/* ===== CSS RESET & BASE STYLES ===== */
        *,
        *::before,
        *::after {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }

        :root {
            --primary: #3498db;
            --primary-dark: #2980b9;
            --primary-light: #e1f0fa;
            --secondary: #27ae60;
            --secondary-dark: #219653;
            --secondary-light: #e8f5e9;
            --danger: #e74c3c;
            --danger-dark: #c0392b;
            --warning: #f39c12;
            --warning-dark: #e67e22;
            --info: #2c3e50;
            --success: #2ecc71;
            --gray-50: #fafafa;
            --gray-100: #f5f5f5;
            --gray-200: #eeeeee;
            --gray-300: #e0e0e0;
            --gray-400: #bdbdbd;
            --gray-500: #9e9e9e;
            --gray-600: #757575;
            --gray-700: #616161;
            --gray-800: #424242;
            --gray-900: #212121;
            --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.12), 0 1px 2px rgba(0, 0, 0, 0.24);
            --shadow-md: 0 3px 6px rgba(0, 0, 0, 0.15), 0 2px 4px rgba(0, 0, 0, 0.12);
            --shadow-lg: 0 10px 20px rgba(0, 0, 0, 0.15), 0 3px 6px rgba(0, 0, 0, 0.10);
            --shadow-xl: 0 15px 25px rgba(0, 0, 0, 0.15), 0 5px 10px rgba(0, 0, 0, 0.05);
            --radius-sm: 4px;
            --radius-md: 8px;
            --radius-lg: 12px;
            --radius-xl: 16px;
            --radius-full: 9999px;
            --transition-fast: 150ms ease;
            --transition-normal: 300ms ease;
            --transition-slow: 500ms ease;
            --font-sans: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            --font-mono: 'SF Mono', 'Monaco', 'Inconsolata', 'Roboto Mono', monospace;
            --font-size-xs: 0.75rem;
            --font-size-sm: 0.875rem;
            --font-size-base: 1rem;
            --font-size-lg: 1.125rem;
            --font-size-xl: 1.25rem;
            --font-size-2xl: 1.5rem;
            --font-size-3xl: 1.875rem;
            --font-size-4xl: 2.25rem;
            --font-size-5xl: 3rem;
            --line-height-tight: 1.25;
            --line-height-normal: 1.5;
            --line-height-relaxed: 1.75;
            --container-width: 1200px;
            --spacing-xs: 0.25rem;
            --spacing-sm: 0.5rem;
            --spacing-md: 1rem;
            --spacing-lg: 1.5rem;
            --spacing-xl: 2rem;
            --spacing-2xl: 3rem;
            --spacing-3xl: 4rem;
            --z-index-dropdown: 1000;
            --z-index-sticky: 1020;
            --z-index-fixed: 1030;
            --z-index-modal: 1040;
            --z-index-popover: 1050;
            --z-index-tooltip: 1060;
            --z-index-toast: 1070;
        }

        html {
            scroll-behavior: smooth;
            font-size: 16px;
            line-height: var(--line-height-normal);
        }

        body {
            font-family: var(--font-sans);
            background: linear-gradient(135deg, var(--gray-50) 0%, var(--gray-100) 100%);
            margin: 0;
            padding: var(--spacing-xl);
            color: var(--gray-900);
            line-height: var(--line-height-normal);
            font-weight: 400;
            min-height: 100vh;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            position: relative;
            overflow-x: hidden;
        }

        body::before {
            content: '';
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: radial-gradient(circle at 50% 50%, rgba(255, 255, 255, 0.8) 0%, rgba(245, 247, 250, 0.8) 100%);
            z-index: -1;
        }

        /* ===== TYPOGRAPHY ===== */
        h1,
        h2,
        h3,
        h4,
        h5,
        h6 {
            font-weight: 700;
            line-height: var(--line-height-tight);
            margin-bottom: var(--spacing-md);
            color: var(--gray-900);
        }

        h1 {
            font-size: var(--font-size-4xl);
            letter-spacing: -0.025em;
            position: relative;
            display: inline-block;
        }

        h1::after {
            content: '';
            position: absolute;
            bottom: -8px;
            left: 0;
            width: 60px;
            height: 4px;
            background: linear-gradient(90deg, var(--primary), var(--secondary));
            border-radius: var(--radius-full);
        }

        h2 {
            font-size: var(--font-size-3xl);
            margin-top: var(--spacing-2xl);
            padding-bottom: var(--spacing-sm);
            border-bottom: 1px solid var(--gray-300);
        }

        h3 {
            font-size: var(--font-size-2xl);
            color: var(--gray-800);
            margin-top: var(--spacing-xl);
        }

        h4 {
            font-size: var(--font-size-xl);
            color: var(--gray-700);
            margin-top: var(--spacing-lg);
        }

        h5 {
            font-size: var(--font-size-lg);
            color: var(--gray-600);
            margin-top: var(--spacing-md);
        }

        h6 {
            font-size: var(--font-size-base);
            color: var(--gray-500);
            text-transform: uppercase;
            letter-spacing: 0.05em;
        }

        p {
            margin-bottom: var(--spacing-md);
            max-width: 65ch;
        }

        a {
            color: var(--primary);
            text-decoration: none;
            transition: color var(--transition-fast);
            position: relative;
        }

        a:hover {
            color: var(--primary-dark);
        }

        a::after {
            content: '';
            position: absolute;
            bottom: -2px;
            left: 0;
            width: 0;
            height: 1px;
            background-color: var(--primary);
            transition: width var(--transition-normal);
        }

        a:hover::after {
            width: 100%;
        }

        strong {
            font-weight: 600;
            color: var(--gray-900);
        }

        em {
            font-style: italic;
            color: var(--gray-700);
        }

        blockquote {
            border-left: 4px solid var(--primary);
            padding-left: var(--spacing-lg);
            margin: var(--spacing-xl) 0;
            font-style: italic;
            color: var(--gray-700);
            background-color: var(--gray-50);
            padding: var(--spacing-lg);
            border-radius: 0 var(--radius-md) var(--radius-md) 0;
        }

        code {
            font-family: var(--font-mono);
            background-color: var(--gray-100);
            padding: var(--spacing-xs) var(--spacing-sm);
            border-radius: var(--radius-sm);
            font-size: var(--font-size-sm);
            color: var(--danger-dark);
            border: 1px solid var(--gray-200);
        }

        pre {
            background-color: var(--gray-900);
            color: var(--gray-100);
            padding: var(--spacing-lg);
            border-radius: var(--radius-md);
            overflow-x: auto;
            margin: var(--spacing-lg) 0;
            font-family: var(--font-mono);
            font-size: var(--font-size-sm);
            line-height: var(--line-height-normal);
            box-shadow: var(--shadow-md);
        }

        pre code {
            background-color: transparent;
            color: inherit;
            padding: 0;
            border: none;
            font-size: inherit;
        }

        /* ===== LAYOUT & CONTAINERS ===== */
        .container {
            max-width: var(--container-width);
            width: 100%;
            margin: var(--spacing-2xl) auto;
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(10px);
            padding: var(--spacing-2xl);
            border-radius: var(--radius-xl);
            box-shadow: var(--shadow-xl);
            position: relative;
            overflow: hidden;
            border: 1px solid rgba(255, 255, 255, 0.5);
        }

        .container::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 6px;
            background: linear-gradient(90deg, var(--primary), var(--secondary), var(--warning), var(--danger));
            border-radius: var(--radius-xl) var(--radius-xl) 0 0;
        }

        .header {
            text-align: center;
            margin-bottom: var(--spacing-2xl);
            padding-bottom: var(--spacing-xl);
            border-bottom: 1px solid var(--gray-200);
            position: relative;
        }

        .tagline {
            color: var(--gray-600);
            font-size: var(--font-size-lg);
            margin-top: var(--spacing-sm);
            font-weight: 300;
            letter-spacing: 0.02em;
        }

        .main-content {
            display: grid;
            grid-template-columns: 1fr 1.2fr;
            gap: var(--spacing-2xl);
            margin-top: var(--spacing-xl);
        }

        .left-panel {
            grid-column: 1;
            display: flex;
            flex-direction: column;
            gap: var(--spacing-xl);
        }

        .right-panel {
            grid-column: 2;
            display: flex;
            flex-direction: column;
            gap: var(--spacing-xl);
        }

        .section {
            background: var(--gray-50);
            border-radius: var(--radius-lg);
            padding: var(--spacing-lg);
            border: 1px solid var(--gray-200);
            transition: transform var(--transition-normal), box-shadow var(--transition-normal);
        }

        .section:hover {
            transform: translateY(-2px);
            box-shadow: var(--shadow-md);
        }

        .section-title {
            display: flex;
            align-items: center;
            gap: var(--spacing-sm);
            margin-bottom: var(--spacing-lg);
            padding-bottom: var(--spacing-sm);
            border-bottom: 1px solid var(--gray-200);
            color: var(--gray-800);
            font-weight: 600;
        }

        .section-title svg {
            color: var(--primary);
        }

        /* ===== DROP ZONE ===== */
        .drop-zone {
            border: 2px dashed var(--primary);
            border-radius: var(--radius-lg);
            padding: var(--spacing-2xl) var(--spacing-xl);
            margin: var(--spacing-lg) 0;
            cursor: pointer;
            transition: all var(--transition-normal);
            text-align: center;
            position: relative;
            background: var(--gray-50);
            min-height: 200px;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
        }

        .drop-zone:hover {
            background-color: var(--primary-dark);
            border-color: var(--primary-light);
            transform: translateY(-2px);
            box-shadow: var(--shadow-md);
        }

        .drop-zone.dragover {
            background-color: var(--primary-light);
            border-color: var(--primary-dark);
            transform: scale(1.02);
            box-shadow: var(--shadow-lg);
        }

        .drop-zone p {
            margin: var(--spacing-sm) 0;
            color: var(--gray-600);
        }

        .drop-zone .browse-btn {
            background-color: var(--primary);
            color: white;
            border: none;
            padding: var(--spacing-sm) var(--spacing-lg);
            border-radius: var(--radius-md);
            cursor: pointer;
            font-size: var(--font-size-base);
            margin-top: var(--spacing-md);
            transition: all var(--transition-normal);
            display: inline-flex;
            align-items: center;
            gap: var(--spacing-sm);
            box-shadow: var(--shadow-sm);
        }

        .drop-zone .browse-btn:hover {
            background-color: var(--primary-dark);
            transform: translateY(-2px);
            box-shadow: var(--shadow-md);
        }

        .drop-zone .browse-btn:active {
            transform: translateY(0);
            box-shadow: var(--shadow-sm);
        }

        .file-input {
            display: none;
        }

        /* ===== FILE COUNT ===== */
        .file-count {
            margin: var(--spacing-md) 0;
            font-weight: 500;
            color: var(--gray-600);
            display: flex;
            align-items: center;
            gap: var(--spacing-sm);
            padding: var(--spacing-sm) var(--spacing-md);
            background: var(--gray-100);
            border-radius: var(--radius-md);
            border: 1px solid var(--gray-200);
        }

        /* ===== OPTIONS PANEL ===== */
        .options {
            background: linear-gradient(to bottom, var(--gray-50), var(--gray-100));
            border-radius: var(--radius-lg);
            padding: var(--spacing-xl);
            border: 1px solid var(--gray-300);
            box-shadow: var(--shadow-sm);
        }

        .option-group {
            margin-bottom: var(--spacing-xl);
            padding-bottom: var(--spacing-lg);
            border-bottom: 1px solid var(--gray-200);
        }

        .option-group:last-child {
            margin-bottom: 0;
            padding-bottom: 0;
            border-bottom: none;
        }

        .option-title {
            font-weight: 600;
            margin-bottom: var(--spacing-md);
            color: var(--gray-800);
            display: flex;
            align-items: center;
            gap: var(--spacing-sm);
            font-size: var(--font-size-lg);
        }

        .option-title svg {
            color: var(--primary);
            flex-shrink: 0;
        }

        label {
            display: block;
            margin-bottom: var(--spacing-xs);
            font-weight: 500;
            color: var(--gray-700);
            font-size: var(--font-size-sm);
        }

        input[type="text"],
        input[type="number"],
        input[type="email"],
        input[type="password"],
        input[type="url"],
        input[type="tel"],
        input[type="date"],
        select,
        textarea {
            width: 100%;
            padding: var(--spacing-sm) var(--spacing-md);
            border: 1px solid var(--gray-300);
            border-radius: var(--radius-md);
            margin-bottom: var(--spacing-md);
            font-family: var(--font-sans);
            font-size: var(--font-size-base);
            transition: all var(--transition-fast);
            background: white;
            color: var(--gray-800);
        }

        input[type="text"]:focus,
        input[type="number"]:focus,
        input[type="email"]:focus,
        input[type="password"]:focus,
        input[type="url"]:focus,
        input[type="tel"]:focus,
        input[type="date"]:focus,
        select:focus,
        textarea:focus {
            outline: none;
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.1);
            transform: translateY(-1px);
        }

        .checkbox-group {
            margin: var(--spacing-md) 0;
            display: flex;
            align-items: center;
        }

        .checkbox-group label {
            display: flex;
            align-items: center;
            font-weight: normal;
            cursor: pointer;
            margin-bottom: 0;
            color: var(--gray-700);
            font-size: var(--font-size-base);
        }

        .checkbox-group input[type="checkbox"] {
            margin-right: var(--spacing-sm);
            cursor: pointer;
            width: 18px;
            height: 18px;
            accent-color: var(--primary);
        }

        /* ===== ADVANCED OPTIONS ===== */
        .advanced-options {
            margin-top: var(--spacing-lg);
            padding-top: var(--spacing-lg);
            border-top: 1px dashed var(--gray-300);
        }

        .toggle-advanced {
            background: none;
            border: none;
            color: var(--primary);
            cursor: pointer;
            font-size: var(--font-size-sm);
            display: flex;
            align-items: center;
            padding: 0;
            margin-top: var(--spacing-md);
            transition: color var(--transition-fast);
            font-weight: 500;
        }

        .toggle-advanced:hover {
            color: var(--primary-dark);
        }

        .toggle-advanced svg {
            margin-right: var(--spacing-xs);
            transition: transform var(--transition-normal);
        }

        .toggle-advanced[aria-expanded="true"] svg {
            transform: rotate(180deg);
        }

        /* ===== PREVIEW AREA ===== */
        .preview-container {
            border: 1px solid var(--gray-300);
            border-radius: var(--radius-lg);
            overflow: hidden;
            background: white;
            box-shadow: var(--shadow-sm);
            height: 100%;
            display: flex;
            flex-direction: column;
        }

        .preview-header {
            background: linear-gradient(to right, var(--gray-100), var(--gray-200));
            padding: var(--spacing-md) var(--spacing-lg);
            font-weight: 600;
            display: flex;
            justify-content: space-between;
            align-items: center;
            border-bottom: 1px solid var(--gray-300);
            color: var(--gray-700);
        }

        .preview-content {
            flex: 1;
            overflow-y: auto;
            padding: var(--spacing-md);
            background: var(--gray-50);
            max-height: 400px;
        }

        .file-preview {
            display: flex;
            justify-content: space-between;
            padding: var(--spacing-sm) 0;
            border-bottom: 1px solid var(--gray-200);
            font-family: var(--font-mono);
            font-size: var(--font-size-sm);
            align-items: center;
            gap: var(--spacing-md);
        }

        .file-preview:last-child {
            border-bottom: none;
        }

        .original-name {
            color: var(--gray-600);
            text-overflow: ellipsis;
            overflow: hidden;
            white-space: nowrap;
            flex: 1;
        }

        .new-name {
            color: var(--secondary);
            font-weight: 500;
            text-overflow: ellipsis;
            overflow: hidden;
            white-space: nowrap;
            flex: 1;
            text-align: right;
        }

        /* ===== ACTION BUTTONS ===== */
        .action-buttons {
            margin-top: var(--spacing-xl);
            display: flex;
            gap: var(--spacing-md);
        }

        .btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: var(--spacing-sm);
            padding: var(--spacing-md) var(--spacing-lg);
            border-radius: var(--radius-md);
            cursor: pointer;
            font-size: var(--font-size-base);
            font-weight: 500;
            transition: all var(--transition-normal);
            border: none;
            text-decoration: none;
            position: relative;
            overflow: hidden;
        }

        .btn::before {
            content: '';
            position: absolute;
            top: 0;
            left: -100%;
            width: 100%;
            height: 100%;
            background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
            transition: left 0.5s;
        }

        .btn:hover::before {
            left: 100%;
        }

        .btn-primary {
            background: linear-gradient(135deg, var(--primary), var(--primary-dark));
            color: white;
            box-shadow: var(--shadow-md);
        }

        .btn-primary:hover {
            background: linear-gradient(135deg, var(--primary-dark), var(--primary));
            transform: translateY(-2px);
            box-shadow: var(--shadow-lg);
        }

        .btn-primary:active {
            transform: translateY(0);
            box-shadow: var(--shadow-md);
        }

        .btn-secondary {
            background: linear-gradient(135deg, var(--secondary), var(--secondary-dark));
            color: white;
            box-shadow: var(--shadow-md);
        }

        .btn-secondary:hover {
            background: linear-gradient(135deg, var(--secondary-dark), var(--secondary));
            transform: translateY(-2px);
            box-shadow: var(--shadow-lg);
        }

        .btn-danger {
            background: linear-gradient(135deg, var(--danger), var(--danger-dark));
            color: white;
            box-shadow: var(--shadow-md);
        }

        .btn-danger:hover {
            background: linear-gradient(135deg, var(--danger-dark), var(--danger));
            transform: translateY(-2px);
            box-shadow: var(--shadow-lg);
        }

        .btn:disabled {
            background: var(--gray-400);
            color: var(--gray-600);
            cursor: not-allowed;
            transform: none;
            box-shadow: none;
        }

        .btn:disabled:hover {
            background: var(--gray-400);
            transform: none;
            box-shadow: none;
        }

        .btn-lg {
            padding: var(--spacing-md) var(--spacing-xl);
            font-size: var(--font-size-lg);
        }

        .btn-sm {
            padding: var(--spacing-xs) var(--spacing-md);
            font-size: var(--font-size-sm);
        }

        .btn-full {
            width: 100%;
        }

        /* ===== TOAST NOTIFICATIONS ===== */
        .toast {
            position: fixed;
            bottom: var(--spacing-xl);
            right: var(--spacing-xl);
            padding: var(--spacing-md) var(--spacing-lg);
            background-color: var(--info);
            color: white;
            border-radius: var(--radius-md);
            box-shadow: var(--shadow-lg);
            opacity: 0;
            transition: opacity var(--transition-normal), transform var(--transition-normal);
            transform: translateY(20px);
            z-index: var(--z-index-toast);
            display: flex;
            align-items: center;
            gap: var(--spacing-sm);
            max-width: 400px;
        }

        .toast.show {
            opacity: 1;
            transform: translateY(0);
        }

        .toast-success {
            background-color: var(--success);
        }

        .toast-error {
            background-color: var(--danger);
        }

        .toast-warning {
            background-color: var(--warning);
        }

        .toast-info {
            background-color: var(--info);
        }

        /* ===== ANIMATIONS ===== */
        @keyframes fileAdded {
            0% {
                background-color: var(--primary-light);
                transform: scale(1.02);
            }

            100% {
                background-color: transparent;
                transform: scale(1);
            }
        }

        .file-added {
            animation: fileAdded 1s ease;
        }

        @keyframes spin {
            0% {
                transform: rotate(0deg);
            }

            100% {
                transform: rotate(360deg);
            }
        }

        .spinner {
            animation: spin 1s linear infinite;
        }

        @keyframes fadeIn {
            from {
                opacity: 0;
                transform: translateY(10px);
            }

            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        .fade-in {
            animation: fadeIn 0.3s ease forwards;
        }

        @keyframes slideIn {
            from {
                opacity: 0;
                transform: translateX(20px);
            }

            to {
                opacity: 1;
                transform: translateX(0);
            }
        }

        .slide-in {
            animation: slideIn 0.3s ease forwards;
        }

        @keyframes pulse {
            0% {
                transform: scale(1);
            }

            50% {
                transform: scale(1.05);
            }

            100% {
                transform: scale(1);
            }
        }

        .pulse {
            animation: pulse 2s infinite;
        }

        /* ===== ICONS ===== */
        .icon {
            width: 18px;
            height: 18px;
            vertical-align: middle;
            margin-right: var(--spacing-xs);
            flex-shrink: 0;
        }

        .icon-sm {
            width: 16px;
            height: 16px;
        }

        .icon-lg {
            width: 24px;
            height: 24px;
        }

        .icon-xl {
            width: 32px;
            height: 32px;
        }

        /* ===== UTILITY CLASSES ===== */
        .text-center {
            text-align: center;
        }

        .text-left {
            text-align: left;
        }

        .text-right {
            text-align: right;
        }

        .mt-0 {
            margin-top: 0;
        }

        .mt-1 {
            margin-top: var(--spacing-xs);
        }

        .mt-2 {
            margin-top: var(--spacing-sm);
        }

        .mt-3 {
            margin-top: var(--spacing-md);
        }

        .mt-4 {
            margin-top: var(--spacing-lg);
        }

        .mt-5 {
            margin-top: var(--spacing-xl);
        }

        .mt-6 {
            margin-top: var(--spacing-2xl);
        }

        .mb-0 {
            margin-bottom: 0;
        }

        .mb-1 {
            margin-bottom: var(--spacing-xs);
        }

        .mb-2 {
            margin-bottom: var(--spacing-sm);
        }

        .mb-3 {
            margin-bottom: var(--spacing-md);
        }

        .mb-4 {
            margin-bottom: var(--spacing-lg);
        }

        .mb-5 {
            margin-bottom: var(--spacing-xl);
        }

        .mb-6 {
            margin-bottom: var(--spacing-2xl);
        }

        .p-0 {
            padding: 0;
        }

        .p-1 {
            padding: var(--spacing-xs);
        }

        .p-2 {
            padding: var(--spacing-sm);
        }

        .p-3 {
            padding: var(--spacing-md);
        }

        .p-4 {
            padding: var(--spacing-lg);
        }

        .p-5 {
            padding: var(--spacing-xl);
        }

        .p-6 {
            padding: var(--spacing-2xl);
        }

        .d-flex {
            display: flex;
        }

        .d-inline-flex {
            display: inline-flex;
        }

        .d-block {
            display: block;
        }

        .d-inline-block {
            display: inline-block;
        }

        .d-none {
            display: none;
        }

        .align-items-center {
            align-items: center;
        }

        .align-items-start {
            align-items: flex-start;
        }

        .align-items-end {
            align-items: flex-end;
        }

        .justify-content-center {
            justify-content: center;
        }

        .justify-content-between {
            justify-content: space-between;
        }

        .justify-content-around {
            justify-content: space-around;
        }

        .justify-content-start {
            justify-content: flex-start;
        }

        .justify-content-end {
            justify-content: flex-end;
        }

        .flex-column {
            flex-direction: column;
        }

        .flex-row {
            flex-direction: row;
        }

        .flex-wrap {
            flex-wrap: wrap;
        }

        .w-100 {
            width: 100%;
        }

        .w-75 {
            width: 75%;
        }

        .w-50 {
            width: 50%;
        }

        .w-25 {
            width: 25%;
        }

        .h-100 {
            height: 100%;
        }

        .h-75 {
            height: 75%;
        }

        .h-50 {
            height: 50%;
        }

        .h-25 {
            height: 25%;
        }

        .rounded {
            border-radius: var(--radius-md);
        }

        .rounded-sm {
            border-radius: var(--radius-sm);
        }

        .rounded-lg {
            border-radius: var(--radius-lg);
        }

        .rounded-full {
            border-radius: var(--radius-full);
        }

        .shadow {
            box-shadow: var(--shadow-md);
        }

        .shadow-sm {
            box-shadow: var(--shadow-sm);
        }

        .shadow-lg {
            box-shadow: var(--shadow-lg);
        }

        .shadow-none {
            box-shadow: none;
        }

        .border {
            border: 1px solid var(--gray-300);
        }

        .border-0 {
            border: none;
        }

        .position-relative {
            position: relative;
        }

        .position-absolute {
            position: absolute;
        }

        .position-fixed {
            position: fixed;
        }

        .position-sticky {
            position: sticky;
        }

        .overflow-hidden {
            overflow: hidden;
        }

        .overflow-auto {
            overflow: auto;
        }

        .overflow-scroll {
            overflow: scroll;
        }

        /* ===== RESPONSIVE DESIGN ===== */
        @media (max-width: 1024px) {
            .container {
                margin: var(--spacing-xl) auto;
                padding: var(--spacing-xl);
            }

            .main-content {
                grid-template-columns: 1fr;
                gap: var(--spacing-xl);
            }

            .right-panel {
                grid-column: 1;
            }

            h1 {
                font-size: var(--font-size-3xl);
            }

            h2 {
                font-size: var(--font-size-2xl);
            }
        }

        @media (max-width: 768px) {
            body {
                padding: var(--spacing-md);
            }

            .container {
                padding: var(--spacing-lg);
                border-radius: var(--radius-lg);
            }

            .action-buttons {
                flex-direction: column;
            }

            .btn {
                width: 100%;
            }

            .file-preview {
                flex-direction: column;
                align-items: flex-start;
                gap: var(--spacing-xs);
            }

            .new-name {
                text-align: left;
            }

            .toast {
                left: var(--spacing-md);
                right: var(--spacing-md);
                bottom: var(--spacing-md);
                max-width: none;
            }
        }

        @media (max-width: 480px) {
            :root {
                --spacing-xl: 1.5rem;
                --spacing-2xl: 2rem;
            }

            body {
                padding: var(--spacing-sm);
            }

            .container {
                padding: var(--spacing-md);
                border-radius: var(--radius-md);
            }

            h1 {
                font-size: var(--font-size-2xl);
            }

            .drop-zone {
                padding: var(--spacing-xl) var(--spacing-md);
            }

            .options {
                padding: var(--spacing-md);
            }

            .section {
                padding: var(--spacing-md);
            }
        }

        /* ===== PRINT STYLES ===== */
        @media print {
            body {
                background: white;
                padding: 0;
                color: black;
            }

            .container {
                box-shadow: none;
                border: none;
                margin: 0;
                padding: 0;
                width: 100%;
                max-width: 100%;
            }

            .action-buttons,
            .drop-zone,
            .file-input,
            .toggle-advanced,
            .toast {
                display: none !important;
            }

            .options {
                display: block !important;
                border: none;
                background: white;
            }

            .preview-container {
                break-inside: avoid;
            }

            a {
                color: black;
                text-decoration: underline;
            }

            a::after {
                content: " (" attr(href) ") ";
            }
        }

        /* ===== DARK MODE SUPPORT ===== */
        @media (prefers-color-scheme: dark) {
            :root {
                --gray-50: #1a1a1a;
                --gray-100: #242424;
                --gray-200: #333333;
                --gray-300: #444444;
                --gray-400: #666666;
                --gray-500: #888888;
                --gray-600: #aaaaaa;
                --gray-700: #cccccc;
                --gray-800: #e5e5e5;
                --gray-900: #ffffff;
            }

            body {
                background: linear-gradient(135deg, #121212 0%, #1a1a1a 100%);
                color: var(--gray-800);
            }

            body::before {
                background: radial-gradient(circle at 50% 50%, rgba(30, 30, 30, 0.8) 0%, rgba(26, 26, 26, 0.8) 100%);
            }

            .container {
                background: rgba(30, 30, 30, 0.95);
                border: 1px solid rgba(255, 255, 255, 0.1);
            }

            .section {
                background: var(--gray-100);
                border-color: var(--gray-300);
            }

            .drop-zone {
                background: var(--gray-100);
                border-color: var(--primary);
            }

            .options {
                background: linear-gradient(to bottom, var(--gray-100), var(--gray-200));
                border-color: var(--gray-300);
            }

            input[type="text"],
            input[type="number"],
            input[type="email"],
            input[type="password"],
            input[type="url"],
            input[type="tel"],
            input[type="date"],
            select,
            textarea {
                background: var(--gray-200);
                border-color: var(--gray-400);
                color: var(--gray-800);
            }

            .preview-container {
                background: var(--gray-100);
                border-color: var(--gray-300);
            }

            .preview-header {
                background: linear-gradient(to right, var(--gray-200), var(--gray-300));
                border-color: var(--gray-400);
            }

            .preview-content {
                background: var(--gray-100);
            }

            .file-count {
                background: var(--gray-200);
                border-color: var(--gray-300);
            }
        }

        /* ===== HIGH CONTRAST MODE SUPPORT ===== */
        @media (prefers-contrast: high) {
            :root {
                --primary: #0000ff;
                --primary-dark: #0000cc;
                --secondary: #008000;
                --secondary-dark: #006400;
                --danger: #ff0000;
                --danger-dark: #cc0000;
            }

            body {
                background: white;
                color: black;
            }

            .container {
                border: 2px solid black;
            }

            .drop-zone {
                border: 2px dashed black;
            }

            input,
            select,
            textarea {
                border: 2px solid black;
            }
        }

        /* ===== REDUCED MOTION SUPPORT ===== */
        @media (prefers-reduced-motion: reduce) {

            *,
            *::before,
            *::after {
                animation-duration: 0.01ms !important;
                animation-iteration-count: 1 !important;
                transition-duration: 0.01ms !important;
                scroll-behavior: auto !important;
            }

            .btn::before {
                display: none;
            }
        }

        /* ===== CUSTOM SCROLLBAR ===== */
        ::-webkit-scrollbar {
            width: 8px;
            height: 8px;
        }

        ::-webkit-scrollbar-track {
            background: var(--gray-100);
            border-radius: var(--radius-full);
        }

        ::-webkit-scrollbar-thumb {
            background: var(--gray-400);
            border-radius: var(--radius-full);
        }

        ::-webkit-scrollbar-thumb:hover {
            background: var(--gray-500);
        }

        /* ===== SELECTION STYLES ===== */
        ::selection {
            background-color: rgba(52, 152, 219, 0.3);
            color: inherit;
        }

        ::-moz-selection {
            background-color: rgba(52, 152, 219, 0.3);
            color: inherit;
        }

        /* ===== FOCUS STYLES ===== */
        :focus-visible {
            outline: 2px solid var(--primary);
            outline-offset: 2px;
        }

        /* ===== PLACEHOLDER STYLES ===== */
        ::placeholder {
            color: var(--gray-500);
            opacity: 1;
        }

        :-ms-input-placeholder {
            color: var(--gray-500);
        }

        ::-ms-input-placeholder {
            color: var(--gray-500);
        }

        /* ===== ACCESSIBILITY ===== */
        .sr-only {
            position: absolute;
            width: 1px;
            height: 1px;
            padding: 0;
            margin: -1px;
            overflow: hidden;
            clip: rect(0, 0, 0, 0);
            white-space: nowrap;
            border: 0;
        }

        .skip-link {
            position: absolute;
            top: -40px;
            left: 0;
            background: var(--primary);
            color: white;
            padding: var(--spacing-sm) var(--spacing-md);
            text-decoration: none;
            z-index: var(--z-index-skip-link);
            transition: top 0.3s;
        }

        .skip-link:focus {
            top: 0;
        }

        /* ===== LOADING STATES ===== */
        .is-loading {
            position: relative;
            color: transparent !important;
            pointer-events: none;
        }

        .is-loading::after {
            content: '';
            position: absolute;
            top: 50%;
            left: 50%;
            width: 20px;
            height: 20px;
            margin: -10px 0 0 -10px;
            border: 2px solid rgba(255, 255, 255, 0.3);
            border-radius: 50%;
            border-top-color: white;
            animation: spin 0.8s ease infinite;
        }

        /* ===== VALIDATION STATES ===== */
        .is-valid {
            border-color: var(--success) !important;
            box-shadow: 0 0 0 3px rgba(46, 204, 113, 0.1) !important;
        }

        .is-invalid {
            border-color: var(--danger) !important;
            box-shadow: 0 0 0 3px rgba(231, 76, 60, 0.1) !important;
        }

        .validation-message {
            font-size: var(--font-size-sm);
            margin-top: calc(var(--spacing-xs) * -1);
            margin-bottom: var(--spacing-md);
        }

        .validation-message.is-valid {
            color: var(--success);
        }

        .validation-message.is-invalid {
            color: var(--danger);
        }

        /* ===== CUSTOM CHECKBOX AND RADIO ===== */
        .form-check {
            display: flex;
            align-items: center;
            gap: var(--spacing-sm);
            margin-bottom: var(--spacing-sm);
        }

        .form-check-input {
            width: 18px;
            height: 18px;
            margin: 0;
        }

        .form-check-label {
            margin: 0;
            font-weight: normal;
        }

        /* ===== CUSTOM RANGE SLIDER ===== */
        .form-range {
            width: 100%;
            height: 8px;
            background: var(--gray-300);
            border-radius: var(--radius-full);
            outline: none;
            margin: var(--spacing-md) 0;
            -webkit-appearance: none;
        }

        .form-range::-webkit-slider-thumb {
            -webkit-appearance: none;
            width: 20px;
            height: 20px;
            background: var(--primary);
            border-radius: 50%;
            cursor: pointer;
        }

        .form-range::-moz-range-thumb {
            width: 20px;
            height: 20px;
            background: var(--primary);
            border-radius: 50%;
            cursor: pointer;
            border: none;
        }

        /* ===== CUSTOM FILE UPLOAD ===== */
        .custom-file {
            position: relative;
            display: inline-block;
            width: 100%;
            margin-bottom: var(--spacing-md);
        }

        .custom-file-input {
            position: relative;
            z-index: 2;
            width: 100%;
            height: calc(2.25rem + 2px);
            margin: 0;
            opacity: 0;
        }

        .custom-file-label {
            position: absolute;
            top: 0;
            right: 0;
            left: 0;
            z-index: 1;
            height: calc(2.25rem + 2px);
            padding: var(--spacing-sm) var(--spacing-md);
            line-height: 1.5;
            color: var(--gray-700);
            background-color: white;
            border: 1px solid var(--gray-300);
            border-radius: var(--radius-md);
        }

        .custom-file-label::after {
            position: absolute;
            top: 0;
            right: 0;
            bottom: 0;
            z-index: 3;
            display: block;
            height: 100%;
            padding: var(--spacing-sm) var(--spacing-md);
            line-height: 1.5;
            color: var(--gray-700);
            content: "Browse";
            background-color: var(--gray-200);
            border-left: 1px solid var(--gray-300);
            border-radius: 0 var(--radius-md) var(--radius-md) 0;
        }

        /* ===== TOOLTIPS ===== */
        .tooltip {
            position: relative;
            display: inline-block;
        }

        .tooltip .tooltip-text {
            visibility: hidden;
            width: 120px;
            background-color: var(--gray-800);
            color: white;
            text-align: center;
            border-radius: var(--radius-sm);
            padding: var(--spacing-xs) var(--spacing-sm);
            position: absolute;
            z-index: var(--z-index-tooltip);
            bottom: 125%;
            left: 50%;
            transform: translateX(-50%);
            opacity: 0;
            transition: opacity var(--transition-normal);
            font-size: var(--font-size-sm);
        }

        .tooltip .tooltip-text::after {
            content: "";
            position: absolute;
            top: 100%;
            left: 50%;
            margin-left: -5px;
            border-width: 5px;
            border-style: solid;
            border-color: var(--gray-800) transparent transparent transparent;
        }

        .tooltip:hover .tooltip-text {
            visibility: visible;
            opacity: 1;
        }

        /* ===== PROGRESS BARS ===== */
        .progress {
            display: flex;
            height: 1rem;
            overflow: hidden;
            line-height: 0;
            font-size: var(--font-size-xs);
            background-color: var(--gray-200);
            border-radius: var(--radius-full);
            margin-bottom: var(--spacing-md);
        }

        .progress-bar {
            display: flex;
            flex-direction: column;
            justify-content: center;
            overflow: hidden;
            color: white;
            text-align: center;
            white-space: nowrap;
            background-color: var(--primary);
            transition: width var(--transition-slow);
        }

        .progress-bar-striped {
            background-image: linear-gradient(45deg, rgba(255, 255, 255, 0.15) 25%, transparent 25%, transparent 50%, rgba(255, 255, 255, 0.15) 50%, rgba(255, 255, 255, 0.15) 75%, transparent 75%, transparent);
            background-size: 1rem 1rem;
        }

        .progress-bar-animated {
            animation: progress-bar-stripes 1s linear infinite;
        }

        @keyframes progress-bar-stripes {
            0% {
                background-position-x: 1rem;
            }
        }

        /* ===== BADGES ===== */
        .badge {
            display: inline-block;
            padding: var(--spacing-xs) var(--spacing-sm);
            font-size: var(--font-size-xs);
            font-weight: 600;
            line-height: 1;
            text-align: center;
            white-space: nowrap;
            vertical-align: baseline;
            border-radius: var(--radius-full);
        }

        .badge-primary {
            color: white;
            background-color: var(--primary);
        }

        .badge-secondary {
            color: white;
            background-color: var(--secondary);
        }

        .badge-success {
            color: white;
            background-color: var(--success);
        }

        .badge-danger {
            color: white;
            background-color: var(--danger);
        }

        .badge-warning {
            color: var(--gray-900);
            background-color: var(--warning);
        }

        .badge-info {
            color: white;
            background-color: var(--info);
        }

        /* ===== ALERTS ===== */
        .alert {
            position: relative;
            padding: var(--spacing-md) var(--spacing-lg);
            margin-bottom: var(--spacing-md);
            border: 1px solid transparent;
            border-radius: var(--radius-md);
        }

        .alert-primary {
            color: #004085;
            background-color: #cce5ff;
            border-color: #b8daff;
        }

        .alert-secondary {
            color: #383d41;
            background-color: #e2e3e5;
            border-color: #d6d8db;
        }

        .alert-success {
            color: #155724;
            background-color: #d4edda;
            border-color: #c3e6cb;
        }

        .alert-danger {
            color: #721c24;
            background-color: #f8d7da;
            border-color: #f5c6cb;
        }

        .alert-warning {
            color: #856404;
            background-color: #fff3cd;
            border-color: #ffeeba;
        }

        .alert-info {
            color: #0c5460;
            background-color: #d1ecf1;
            border-color: #bee5eb;
        }

        .alert-dismissible {
            padding-right: 4rem;
        }

        .alert-dismissible .close {
            position: absolute;
            top: 0;
            right: 0;
            padding: var(--spacing-md) var(--spacing-lg);
            color: inherit;
        }

        /* ===== CUSTOM CONTAINER QUERIES ===== */
        @container (max-width: 600px) {
            .card {
                flex-direction: column;
            }

            .card-image {
                width: 100%;
                height: 200px;
            }
        }

        /* ===== GRID SYSTEM ===== */
        .grid {
            display: grid;
            gap: var(--spacing-md);
        }

        .grid-2 {
            grid-template-columns: repeat(2, 1fr);
        }

        .grid-3 {
            grid-template-columns: repeat(3, 1fr);
        }

        .grid-4 {
            grid-template-columns: repeat(4, 1fr);
        }

        .grid-auto {
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
        }

        /* ===== FLEXBOX GRID ===== */
        .row {
            display: flex;
            flex-wrap: wrap;
            margin: calc(var(--spacing-md) * -1);
        }

        .col {
            flex: 1 0 0%;
            padding: var(--spacing-md);
        }

        .col-1 {
            flex: 0 0 8.333333%;
            max-width: 8.333333%;
        }

        .col-2 {
            flex: 0 0 16.666667%;
            max-width: 16.666667%;
        }

        .col-3 {
            flex: 0 0 25%;
            max-width: 25%;
        }

        .col-4 {
            flex: 0 0 33.333333%;
            max-width: 33.333333%;
        }

        .col-5 {
            flex: 0 0 41.666667%;
            max-width: 41.666667%;
        }

        .col-6 {
            flex: 0 0 50%;
            max-width: 50%;
        }

        .col-7 {
            flex: 0 0 58.333333%;
            max-width: 58.333333%;
        }

        .col-8 {
            flex: 0 0 66.666667%;
            max-width: 66.666667%;
        }

        .col-9 {
            flex: 0 0 75%;
            max-width: 75%;
        }

        .col-10 {
            flex: 0 0 83.333333%;
            max-width: 83.333333%;
        }

        .col-11 {
            flex: 0 0 91.666667%;
            max-width: 91.666667%;
        }

        .col-12 {
            flex: 0 0 100%;
            max-width: 100%;
        }

        /* ===== CARD COMPONENT ===== */
        .card {
            position: relative;
            display: flex;
            flex-direction: column;
            min-width: 0;
            word-wrap: break-word;
            background-color: white;
            background-clip: border-box;
            border: 1px solid var(--gray-300);
            border-radius: var(--radius-lg);
            overflow: hidden;
        }

        .card-header {
            padding: var(--spacing-md) var(--spacing-lg);
            background-color: var(--gray-100);
            border-bottom: 1px solid var(--gray-300);
        }

        .card-body {
            padding: var(--spacing-lg);
            flex: 1 1 auto;
        }

        .card-footer {
            padding: var(--spacing-md) var(--spacing-lg);
            background-color: var(--gray-100);
            border-top: 1px solid var(--gray-300);
        }

        .card-image {
            width: 100%;
            height: 200px;
            object-fit: cover;
        }

        .card-title {
            margin-bottom: var(--spacing-md);
            font-size: var(--font-size-xl);
        }

        .card-text {
            margin-bottom: var(--spacing-md);
        }

        /* ===== MODAL COMPONENT ===== */
        .modal {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            z-index: var(--z-index-modal);
            display: flex;
            align-items: center;
            justify-content: center;
            background-color: rgba(0, 0, 0, 0.5);
            opacity: 0;
            visibility: hidden;
            transition: all var(--transition-normal);
        }

        .modal.show {
            opacity: 1;
            visibility: visible;
        }

        .modal-dialog {
            width: 100%;
            max-width: 500px;
            margin: var(--spacing-xl);
        }

        .modal-content {
            background-color: white;
            border-radius: var(--radius-lg);
            box-shadow: var(--shadow-xl);
            overflow: hidden;
        }

        .modal-header {
            padding: var(--spacing-lg);
            border-bottom: 1px solid var(--gray-300);
            display: flex;
            align-items: center;
            justify-content: space-between;
        }

        .modal-title {
            margin: 0;
            font-size: var(--font-size-xl);
        }

        .modal-close {
            background: none;
            border: none;
            font-size: var(--font-size-xl);
            cursor: pointer;
            color: var(--gray-600);
        }

        .modal-body {
            padding: var(--spacing-lg);
        }

        .modal-footer {
            padding: var(--spacing-lg);
            border-top: 1px solid var(--gray-300);
            display: flex;
            gap: var(--spacing-sm);
            justify-content: flex-end;
        }

        /* ===== TAB COMPONENT ===== */
        .tabs {
            display: flex;
            flex-wrap: wrap;
            margin-bottom: var(--spacing-lg);
            border-bottom: 1px solid var(--gray-300);
        }

        .tab {
            padding: var(--spacing-sm) var(--spacing-lg);
            cursor: pointer;
            border: 1px solid transparent;
            border-bottom: none;
            border-radius: var(--radius-md) var(--radius-md) 0 0;
            margin-bottom: -1px;
            background: var(--gray-100);
        }

        .tab.active {
            background: white;
            border-color: var(--gray-300);
            border-bottom-color: white;
        }

        .tab-content {
            display: none;
        }

        .tab-content.active {
            display: block;
        }

        /* ===== ACCORDION COMPONENT ===== */
        .accordion {
            border: 1px solid var(--gray-300);
            border-radius: var(--radius-md);
            overflow: hidden;
        }

        .accordion-item {
            border-bottom: 1px solid var(--gray-300);
        }

        .accordion-item:last-child {
            border-bottom: none;
        }

        .accordion-header {
            margin: 0;
        }

        .accordion-button {
            width: 100%;
            padding: var(--spacing-md) var(--spacing-lg);
            text-align: left;
            background: var(--gray-100);
            border: none;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: space-between;
            font-weight: 500;
        }

        .accordion-button::after {
            content: '';
            width: 16px;
            height: 16px;
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='%23212529'%3e%3cpath fill-rule='evenodd' d='M1.646 4.646a.5.5 0 0 1 .708 0L8 10.293l5.646-5.647a.5.5 0 0 1 .708.708l-6 6a.5.5 0 0 1-.708 0l-6-6a.5.5 0 0 1 0-.708z'/%3e%3c/svg%3e");
            background-repeat: no-repeat;
            background-size: 16px;
            transition: transform var(--transition-normal);
        }

        .accordion-button[aria-expanded="true"]::after {
            transform: rotate(180deg);
        }

        .accordion-collapse {
            display: none;
        }

        .accordion-collapse.show {
            display: block;
        }

        .accordion-body {
            padding: var(--spacing-md) var(--spacing-lg);
            background: white;
        }

        /* ===== DROPDOWN COMPONENT ===== */
        .dropdown {
            position: relative;
            display: inline-block;
        }

        .dropdown-toggle {
            cursor: pointer;
        }

        .dropdown-menu {
            position: absolute;
            top: 100%;
            left: 0;
            z-index: var(--z-index-dropdown);
            display: none;
            min-width: 160px;
            padding: var(--spacing-sm) 0;
            margin: var(--spacing-xs) 0 0;
            background-color: white;
            border: 1px solid var(--gray-300);
            border-radius: var(--radius-md);
            box-shadow: var(--shadow-lg);
        }

        .dropdown-menu.show {
            display: block;
            animation: fadeIn var(--transition-normal);
        }

        .dropdown-item {
            display: block;
            width: 100%;
            padding: var(--spacing-sm) var(--spacing-md);
            clear: both;
            font-weight: 400;
            color: var(--gray-900);
            text-align: inherit;
            text-decoration: none;
            white-space: nowrap;
            background-color: transparent;
            border: none;
            cursor: pointer;
        }

        .dropdown-item:hover {
            background-color: var(--gray-100);
        }

        .dropdown-divider {
            height: 0;
            margin: var(--spacing-sm) 0;
            overflow: hidden;
            border-top: 1px solid var(--gray-300);
        }

        /* ===== BREADCRUMB COMPONENT ===== */
        .breadcrumb {
            display: flex;
            flex-wrap: wrap;
            padding: var(--spacing-sm) 0;
            margin-bottom: var(--spacing-md);
            list-style: none;
            background-color: transparent;
        }

        .breadcrumb-item {
            display: flex;
            align-items: center;
        }

        .breadcrumb-item+.breadcrumb-item::before {
            content: "/";
            display: inline-block;
            padding: 0 var(--spacing-sm);
            color: var(--gray-600);
        }

        .breadcrumb-item a {
            color: var(--primary);
        }

        .breadcrumb-item.active {
            color: var(--gray-600);
        }

        /* ===== PAGINATION COMPONENT ===== */
        .pagination {
            display: flex;
            padding-left: 0;
            list-style: none;
            border-radius: var(--radius-md);
        }

        .page-item {
            margin: 0 var(--spacing-xs);
        }

        .page-link {
            position: relative;
            display: block;
            padding: var(--spacing-sm) var(--spacing-md);
            color: var(--primary);
            text-decoration: none;
            background-color: white;
            border: 1px solid var(--gray-300);
            border-radius: var(--radius-md);
            transition: all var(--transition-fast);
        }

        .page-link:hover {
            z-index: 2;
            color: var(--primary-dark);
            background-color: var(--gray-100);
            border-color: var(--gray-400);
        }

        .page-item.active .page-link {
            z-index: 3;
            color: white;
            background-color: var(--primary);
            border-color: var(--primary);
        }

        .page-item.disabled .page-link {
            color: var(--gray-600);
            pointer-events: none;
            background-color: white;
            border-color: var(--gray-300);
        }

        /* ===== SPINNER COMPONENT ===== */
        .spinner-border {
            display: inline-block;
            width: 2rem;
            height: 2rem;
            vertical-align: -0.125em;
            border: 0.25em solid currentColor;
            border-right-color: transparent;
            border-radius: 50%;
            animation: spinner-border 0.75s linear infinite;
        }

        .spinner-border-sm {
            width: 1rem;
            height: 1rem;
            border-width: 0.2em;
        }

        @keyframes spinner-border {
            to {
                transform: rotate(360deg);
            }
        }

        /* ===== PLACEHOLDER COMPONENT ===== */
        .placeholder {
            display: inline-block;
            min-height: 1em;
            vertical-align: middle;
            cursor: wait;
            background-color: currentColor;
            opacity: 0.5;
        }

        .placeholder-xs {
            min-height: 0.5em;
        }

        .placeholder-sm {
            min-height: 0.75em;
        }

        .placeholder-lg {
            min-height: 1.25em;
        }

        .placeholder-glow .placeholder {
            animation: placeholder-glow 2s ease-in-out infinite;
        }

        @keyframes placeholder-glow {
            50% {
                opacity: 0.2;
            }
        }

        .placeholder-wave {
            mask-image: linear-gradient(130deg, #000 55%, rgba(0, 0, 0, 0.8) 75%, #000 95%);
            mask-size: 200% 100%;
            animation: placeholder-wave 2s linear infinite;
        }

        @keyframes placeholder-wave {
            100% {
                mask-position: -200% 0%;
            }
        }

        /* ===== RATIO COMPONENT ===== */
        .ratio {
            position: relative;
            width: 100%;
        }

        .ratio::before {
            display: block;
            padding-top: var(--aspect-ratio);
            content: "";
        }

        .ratio>* {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
        }

        .ratio-1x1 {
            --aspect-ratio: 100%;
        }

        .ratio-4x3 {
            --aspect-ratio: calc(3 / 4 * 100%);
        }

        .ratio-16x9 {
            --aspect-ratio: calc(9 / 16 * 100%);
        }

        .ratio-21x9 {
            --aspect-ratio: calc(9 / 21 * 100%);
        }

        /* ===== FIXED POSITIONING ===== */
        .fixed-top {
            position: fixed;
            top: 0;
            right: 0;
            left: 0;
            z-index: var(--z-index-fixed);
        }

        .fixed-bottom {
            position: fixed;
            right: 0;
            bottom: 0;
            left: 0;
            z-index: var(--z-index-fixed);
        }

        .sticky-top {
            position: sticky;
            top: 0;
            z-index: var(--z-index-sticky);
        }

        /* ===== VISIBILITY UTILITIES ===== */
        .visible {
            visibility: visible !important;
        }

        .invisible {
            visibility: hidden !important;
        }

        @media (max-width: 576px) {
            .visible-mobile {
                visibility: visible !important;
            }

            .hidden-mobile {
                visibility: hidden !important;
            }
        }

        /* ===== OPACITY UTILITIES ===== */
        .opacity-0 {
            opacity: 0;
        }

        .opacity-25 {
            opacity: 0.25;
        }

        .opacity-50 {
            opacity: 0.5;
        }

        .opacity-75 {
            opacity: 0.75;
        }

        .opacity-100 {
            opacity: 1;
        }

        /* ===== TEXT UTILITIES ===== */
        .text-truncate {
            overflow: hidden;
            text-overflow: ellipsis;
            white-space: nowrap;
        }

        .text-break {
            word-wrap: break-word;
            word-break: break-word;
        }

        .text-nowrap {
            white-space: nowrap;
        }

        .text-decoration-none {
            text-decoration: none;
        }

        .text-decoration-underline {
            text-decoration: underline;
        }

        .text-decoration-line-through {
            text-decoration: line-through;
        }

        /* ===== VERTICAL ALIGNMENT ===== */
        .align-baseline {
            vertical-align: baseline;
        }

        .align-top {
            vertical-align: top;
        }

        .align-middle {
            vertical-align: middle;
        }

        .align-bottom {
            vertical-align: bottom;
        }

        .align-text-top {
            vertical-align: text-top;
        }

        .align-text-bottom {
            vertical-align: text-bottom;
        }

        /* ===== POINTER EVENTS ===== */
        .pe-none {
            pointer-events: none;
        }

        .pe-auto {
            pointer-events: auto;
        }

        /* ===== USER SELECT ===== */
        .user-select-all {
            user-select: all;
        }

        .user-select-auto {
            user-select: auto;
        }

        .user-select-none {
            user-select: none;
        }

        /* ===== OVERFLOW ===== */
        .overflow-auto {
            overflow: auto;
        }

        .overflow-hidden {
            overflow: hidden;
        }

        .overflow-visible {
            overflow: visible;
        }

        .overflow-scroll {
            overflow: scroll;
        }

        .overflow-x-auto {
            overflow-x: auto;
        }

        .overflow-y-auto {
            overflow-y: auto;
        }

        .overflow-x-hidden {
            overflow-x: hidden;
        }

        .overflow-y-hidden {
            overflow-y: hidden;
        }

        .overflow-x-visible {
            overflow-x: visible;
        }

        .overflow-y-visible {
            overflow-y: visible;
        }

        .overflow-x-scroll {
            overflow-x: scroll;
        }

        .overflow-y-scroll {
            overflow-y: scroll;
        }

        /* ===== FLOAT ===== */
        .float-start {
            float: left;
        }

        .float-end {
            float: right;
        }

        .float-none {
            float: none;
        }

        /* ===== CLEARFIX ===== */
        .clearfix::after {
            display: block;
            clear: both;
            content: "";
        }

        /* ===== POSITION ===== */
        .position-static {
            position: static;
        }

        .position-relative {
            position: relative;
        }

        .position-absolute {
            position: absolute;
        }

        .position-fixed {
            position: fixed;
        }

        .position-sticky {
            position: sticky;
        }

        /* ===== SCROLL MARGIN ===== */
        .scroll-margin {
            scroll-margin-top: var(--spacing-xl);
        }

        /* ===== FOCUS STYLES ===== */
        .focus-ring:focus {
            outline: 0;
            box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.25);
        }

        /* ===== FORM SWITCH ===== */
        .form-switch {
            padding-left: 2.5em;
        }

        .form-switch .form-check-input {
            width: 2em;
            margin-left: -2.5em;
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='-4 -4 8 8'%3e%3ccircle r='3' fill='rgba%280, 0, 0, 0.25%29'/%3e%3c/svg%3e");
            background-position: left center;
            border-radius: 2em;
            transition: background-position 0.15s ease-in-out;
        }

        .form-switch .form-check-input:focus {
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='-4 -4 8 8'%3e%3ccircle r='3' fill='%2386b7fe'/%3e%3c/svg%3e");
        }

        .form-switch .form-check-input:checked {
            background-position: right center;
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='-4 -4 8 8'%3e%3ccircle r='3' fill='%23fff'/%3e%3c/svg%3e");
        }

        /* ===== FORM VALIDATION ===== */
        .was-validated .form-control:valid,
        .form-control.is-valid {
            border-color: var(--success);
            padding-right: calc(1.5em + 0.75rem);
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 8 8'%3e%3cpath fill='%232ecc71' d='M2.3 6.73L.6 4.53c-.4-1.04.46-1.4 1.1-.8l1.1 1.4 3.4-3.8c.6-.63 1.6-.27 1.2.7l-4 4.6c-.43.5-.8.4-1.1.1z'/%3e%3c/svg%3e");
            background-repeat: no-repeat;
            background-position: right calc(0.375em + 0.1875rem) center;
            background-size: calc(0.75em + 0.375rem) calc(0.75em + 0.375rem);
        }

        .was-validated .form-control:valid:focus,
        .form-control.is-valid:focus {
            border-color: var(--success);
            box-shadow: 0 0 0 0.2rem rgba(46, 204, 113, 0.25);
        }

        .was-validated .form-control:invalid,
        .form-control.is-invalid {
            border-color: var(--danger);
            padding-right: calc(1.5em + 0.75rem);
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 12 12' width='12' height='12' fill='none' stroke='%23e74c3c'%3e%3ccircle cx='6' cy='6' r='4.5'/%3e%3cpath stroke-linejoin='round' d='M5.8 3.6h.4L6 6.5z'/%3e%3ccircle cx='6' cy='8.2' r='.6' fill='%23e74c3c' stroke='none'/%3e%3c/svg%3e");
            background-repeat: no-repeat;
            background-position: right calc(0.375em + 0.1875rem) center;
            background-size: calc(0.75em + 0.375rem) calc(0.75em + 0.375rem);
        }

        .was-validated .form-control:invalid:focus,
        .form-control.is-invalid:focus {
            border-color: var(--danger);
            box-shadow: 0 0 0 0.2rem rgba(231, 76, 60, 0.25);
        }

        /* ===== CUSTOM RANGE ===== */
        .form-range::-webkit-slider-thumb {
            appearance: none;
            width: 1rem;
            height: 1rem;
            background-color: var(--primary);
            border: 0;
            border-radius: 1rem;
            transition: background-color 0.15s ease-in-out, border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
        }

        .form-range::-webkit-slider-thumb:active {
            background-color: #b6d4fe;
        }

        .form-range::-webkit-slider-runnable-track {
            width: 100%;
            height: 0.5rem;
            color: transparent;
            cursor: pointer;
            background-color: var(--gray-300);
            border-color: transparent;
            border-radius: 1rem;
        }

        .form-range::-moz-range-thumb {
            width: 1rem;
            height: 1rem;
            background-color: var(--primary);
            border: 0;
            border-radius: 1rem;
            transition: background-color 0.15s ease-in-out, border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
        }

        .form-range::-moz-range-thumb:active {
            background-color: #b6d4fe;
        }

        .form-range::-moz-range-track {
            width: 100%;
            height: 0.5rem;
            color: transparent;
            cursor: pointer;
            background-color: var(--gray-300);
            border-color: transparent;
            border-radius: 1rem;
        }

        .form-range:disabled {
            pointer-events: none;
        }

        .form-range:disabled::-webkit-slider-thumb {
            background-color: var(--gray-500);
        }

        .form-range:disabled::-moz-range-thumb {
            background-color: var(--gray-500);
        }

        /* ===== INPUT GROUP ===== */
        .input-group {
            position: relative;
            display: flex;
            flex-wrap: wrap;
            align-items: stretch;
            width: 100%;
        }

        .input-group>.form-control,
        .input-group>.form-select {
            position: relative;
            flex: 1 1 auto;
            width: 1%;
            min-width: 0;
        }

        .input-group>.form-control:focus,
        .input-group>.form-select:focus {
            z-index: 3;
        }

        .input-group-text {
            display: flex;
            align-items: center;
            padding: 0.375rem 0.75rem;
            font-size: 1rem;
            font-weight: 400;
            line-height: 1.5;
            color: var(--gray-700);
            text-align: center;
            white-space: nowrap;
            background-color: var(--gray-200);
            border: 1px solid var(--gray-300);
            border-radius: 0.375rem;
        }

        .input-group-lg>.form-control,
        .input-group-lg>.form-select,
        .input-group-lg>.input-group-text {
            padding: 0.5rem 1rem;
            font-size: 1.25rem;
            border-radius: 0.5rem;
        }

        .input-group-sm>.form-control,
        .input-group-sm>.form-select,
        .input-group-sm>.input-group-text {
            padding: 0.25rem 0.5rem;
            font-size: 0.875rem;
            border-radius: 0.25rem;
        }

        .input-group:not(.has-validation)> :not(:last-child):not(.dropdown-toggle):not(.dropdown-menu),
        .input-group:not(.has-validation)>.dropdown-toggle:nth-last-child(n + 3) {
            border-top-right-radius: 0;
            border-bottom-right-radius: 0;
        }

        .input-group.has-validation> :nth-last-child(n + 3):not(.dropdown-toggle):not(.dropdown-menu),
        .input-group.has-validation>.dropdown-toggle:nth-last-child(n + 4) {
            border-top-right-radius: 0;
            border-bottom-right-radius: 0;
        }

        .input-group> :not(:first-child):not(.dropdown-menu):not(.valid-tooltip):not(.valid-feedback):not(.invalid-tooltip):not(.invalid-feedback) {
            margin-left: -1px;
            border-top-left-radius: 0;
            border-bottom-left-radius: 0;
        }

        /* ===== FLOATING LABELS ===== */
        .form-floating {
            position: relative;
        }

        .form-floating>.form-control,
        .form-floating>.form-select {
            height: calc(3.5rem + 2px);
            line-height: 1.25;
        }

        .form-floating>label {
            position: absolute;
            top: 0;
            left: 0;
            height: 100%;
            padding: 1rem 0.75rem;
            pointer-events: none;
            border: 1px solid transparent;
            transform-origin: 0 0;
            transition: opacity 0.1s ease-in-out, transform 0.1s ease-in-out;
        }

        .form-floating>.form-control::placeholder {
            color: transparent;
        }

        .form-floating>.form-control:focus,
        .form-floating>.form-control:not(:placeholder-shown) {
            padding-top: 1.625rem;
            padding-bottom: 0.625rem;
        }

        .form-floating>.form-control:focus~label,
        .form-floating>.form-control:not(:placeholder-shown)~label,
        .form-floating>.form-select~label {
            opacity: 0.65;
            transform: scale(0.85) translateY(-0.5rem) translateX(0.15rem);
        }

        .form-floating>.form-control:-webkit-autofill~label {
            opacity: 0.65;
            transform: scale(0.85) translateY(-0.5rem) translateX(0.15rem);
        }

        /* ===== VALIDATION FEEDBACK ===== */
        .valid-feedback {
            display: none;
            width: 100%;
            margin-top: 0.25rem;
            font-size: 0.875em;
            color: var(--success);
        }

        .valid-tooltip {
            position: absolute;
            top: 100%;
            z-index: 5;
            display: none;
            max-width: 100%;
            padding: 0.25rem 0.5rem;
            margin-top: 0.1rem;
            font-size: 0.875rem;
            color: #fff;
            background-color: rgba(46, 204, 113, 0.9);
            border-radius: 0.375rem;
        }

        .was-validated :valid~.valid-feedback,
        .was-validated :valid~.valid-tooltip,
        .is-valid~.valid-feedback,
        .is-valid~.valid-tooltip {
            display: block;
        }

        .invalid-feedback {
            display: none;
            width: 100%;
            margin-top: 0.25rem;
            font-size: 0.875em;
            color: var(--danger);
        }

        .invalid-tooltip {
            position: absolute;
            top: 100%;
            z-index: 5;
            display: none;
            max-width: 100%;
            padding: 0.25rem 0.5rem;
            margin-top: 0.1rem;
            font-size: 0.875rem;
            color: #fff;
            background-color: rgba(231, 76, 60, 0.9);
            border-radius: 0.375rem;
        }

        .was-validated :invalid~.invalid-feedback,
        .was-validated :invalid~.invalid-tooltip,
        .is-invalid~.invalid-feedback,
        .is-invalid~.invalid-tooltip {
            display: block;
        }

        /* ===== CUSTOM FILE INPUT ===== */
        .form-file {
            position: relative;
        }

        .form-file-input {
            position: relative;
            z-index: 2;
            width: 100%;
            height: calc(2.25rem + 2px);
            margin: 0;
            opacity: 0;
        }

        .form-file-label {
            position: absolute;
            top: 0;
            right: 0;
            left: 0;
            z-index: 1;
            height: calc(2.25rem + 2px);
            padding: 0.375rem 0.75rem;
            line-height: 1.5;
            color: var(--gray-700);
            background-color: #fff;
            border: 1px solid var(--gray-300);
            border-radius: 0.375rem;
        }

        .form-file-label::after {
            position: absolute;
            top: 0;
            right: 0;
            bottom: 0;
            z-index: 3;
            display: block;
            height: 100%;
            padding: 0.375rem 0.75rem;
            line-height: 1.5;
            color: var(--gray-700);
            content: "Browse";
            background-color: var(--gray-200);
            border-left: inherit;
            border-radius: 0 0.375rem 0.375rem 0;
        }

        /* ===== CUSTOM FORMS ===== */
        .form-check {
            display: block;
            min-height: 1.5rem;
            padding-left: 1.5em;
            margin-bottom: 0.125rem;
        }

        .form-check .form-check-input {
            float: left;
            margin-left: -1.5em;
        }

        .form-check-input {
            width: 1em;
            height: 1em;
            margin-top: 0.25em;
            vertical-align: top;
            background-color: #fff;
            background-repeat: no-repeat;
            background-position: center;
            background-size: contain;
            border: 1px solid rgba(0, 0, 0, 0.25);
            appearance: none;
            print-color-adjust: exact;
        }

        .form-check-input[type="checkbox"] {
            border-radius: 0.25em;
        }

        .form-check-input[type="radio"] {
            border-radius: 50%;
        }

        .form-check-input:active {
            filter: brightness(90%);
        }

        .form-check-input:focus {
            border-color: #86b7fe;
            outline: 0;
            box-shadow: 0 0 0 0.25rem rgba(13, 110, 253, 0.25);
        }

        .form-check-input:checked {
            background-color: #0d6efd;
            border-color: #0d6efd;
        }

        .form-check-input:checked[type="checkbox"] {
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20'%3e%3cpath fill='none' stroke='%23fff' stroke-linecap='round' stroke-linejoin='round' stroke-width='3' d='m6 10 3 3 6-6'/%3e%3c/svg%3e");
        }

        .form-check-input:checked[type="radio"] {
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='-4 -4 8 8'%3e%3ccircle r='2' fill='%23fff'/%3e%3c/svg%3e");
        }

        .form-check-input[type="checkbox"]:indeterminate {
            background-color: #0d6efd;
            border-color: #0d6efd;
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20'%3e%3cpath fill='none' stroke='%23fff' stroke-linecap='round' stroke-linejoin='round' stroke-width='3' d='M6 10h8'/%3e%3c/svg%3e");
        }

        .form-check-input:disabled {
            pointer-events: none;
            filter: none;
            opacity: 0.5;
        }

        .form-check-input:disabled~.form-check-label,
        .form-check-input[disabled]~.form-check-label {
            opacity: 0.5;
        }

        .form-switch {
            padding-left: 2.5em;
        }

        .form-switch .form-check-input {
            width: 2em;
            margin-left: -2.5em;
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='-4 -4 8 8'%3e%3ccircle r='3' fill='rgba%280, 0, 0, 0.25%29'/%3e%3c/svg%3e");
            background-position: left center;
            border-radius: 2em;
            transition: background-position 0.15s ease-in-out;
        }

        .form-switch .form-check-input:focus {
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='-4 -4 8 8'%3e%3ccircle r='3' fill='%2386b7fe'/%3e%3c/svg%3e");
        }

        .form-switch .form-check-input:checked {
            background-position: right center;
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='-4 -4 8 8'%3e%3ccircle r='3' fill='%23fff'/%3e%3c/svg%3e");
        }

        .form-check-inline {
            display: inline-block;
            margin-right: 1rem;
        }

        .btn-check {
            position: absolute;
            clip: rect(0, 0, 0, 0);
            pointer-events: none;
        }

        .btn-check:disabled+.btn,
        .btn-check[disabled]+.btn {
            pointer-events: none;
            filter: none;
            opacity: 0.65;
        }

        /* ===== CUSTOM SELECT ===== */
        .form-select {
            display: block;
            width: 100%;
            padding: 0.375rem 2.25rem 0.375rem 0.75rem;
            font-size: 1rem;
            font-weight: 400;
            line-height: 1.5;
            color: var(--gray-700);
            background-color: #fff;
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3e%3cpath fill='none' stroke='%23343a40' stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='m2 5 6 6 6-6'/%3e%3c/svg%3e");
            background-repeat: no-repeat;
            background-position: right 0.75rem center;
            background-size: 16px 12px;
            border: 1px solid var(--gray-300);
            border-radius: 0.375rem;
            transition: border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
            appearance: none;
        }

        .form-select:focus {
            border-color: #86b7fe;
            outline: 0;
            box-shadow: 0 0 0 0.25rem rgba(13, 110, 253, 0.25);
        }

        .form-select[multiple],
        .form-select[size]:not([size="1"]) {
            padding-right: 0.75rem;
            background-image: none;
        }

        .form-select:disabled {
            background-color: var(--gray-200);
        }

        .form-select:-moz-focusring {
            color: transparent;
            text-shadow: 0 0 0 var(--gray-700);
        }

        /* ===== CUSTOM RANGE ===== */
        .form-range {
            width: 100%;
            height: 1.5rem;
            padding: 0;
            background-color: transparent;
            appearance: none;
        }

        .form-range:focus {
            outline: 0;
        }

        .form-range:focus::-webkit-slider-thumb {
            box-shadow: 0 0 0 1px #fff, 0 0 0 0.25rem rgba(13, 110, 253, 0.25);
        }

        .form-range:focus::-moz-range-thumb {
            box-shadow: 0 0 0 1px #fff, 0 0 0 0.25rem rgba(13, 110, 253, 0.25);
        }

        .form-range::-moz-focus-outer {
            border: 0;
        }

        .form-range::-webkit-slider-thumb {
            width: 1rem;
            height: 1rem;
            margin-top: -0.25rem;
            background-color: #0d6efd;
            border: 0;
            border-radius: 1rem;
            transition: background-color 0.15s ease-in-out, border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
            appearance: none;
        }

        .form-range::-webkit-slider-thumb:active {
            background-color: #b6d4fe;
        }

        .form-range::-webkit-slider-runnable-track {
            width: 100%;
            height: 0.5rem;
            color: transparent;
            cursor: pointer;
            background-color: var(--gray-300);
            border-color: transparent;
            border-radius: 1rem;
        }

        .form-range::-moz-range-thumb {
            width: 1rem;
            height: 1rem;
            background-color: #0d6efd;
            border: 0;
            border-radius: 1rem;
            transition: background-color 0.15s ease-in-out, border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
            appearance: none;
        }

        .form-range::-moz-range-thumb:active {
            background-color: #b6d4fe;
        }

        .form-range::-moz-range-track {
            width: 100%;
            height: 0.5rem;
            color: transparent;
            cursor: pointer;
            background-color: var(--gray-300);
            border-color: transparent;
            border-radius: 1rem;
        }

        .form-range:disabled {
            pointer-events: none;
        }

        .form-range:disabled::-webkit-slider-thumb {
            background-color: var(--gray-500);
        }

        .form-range:disabled::-moz-range-thumb {
            background-color: var(--gray-500);
        }

        /* ===== CUSTOM FILE INPUT ===== */
        .form-file {
            position: relative;
        }

        .form-file-input {
            position: relative;
            z-index: 2;
            width: 100%;
            height: calc(2.25rem + 2px);
            margin: 0;
            opacity: 0;
        }

        .form-file-label {
            position: absolute;
            top: 0;
            right: 0;
            left: 0;
            z-index: 1;
            height: calc(2.25rem + 2px);
            padding: 0.375rem 0.75rem;
            line-height: 1.5;
            color: var(--gray-700);
            background-color: #fff;
            border: 1px solid var(--gray-300);
            border-radius: 0.375rem;
        }

        .form-file-label::after {
            position: absolute;
            top: 0;
            right: 0;
            bottom: 0;
            z-index: 3;
            display: block;
            height: 100%;
            padding: 0.375rem 0.75rem;
            line-height: 1.5;
            color: var(--gray-700);
            content: "Browse";
            background-color: var(--gray-200);
            border-left: inherit;
            border-radius: 0 0.375rem 0.375rem 0;
        }

        .form-file-sm {
            height: calc(1.875rem + 2px);
        }

        .form-file-lg {
            height: calc(2.875rem + 2px);
        }

        .form-file-input:focus~.form-file-label {
            border-color: #86b7fe;
            box-shadow: 0 0 0 0.25rem rgba(13, 110, 253, 0.25);
        }

        .form-file-input:disabled~.form-file-label {
            background-color: var(--gray-200);
        }

        .form-file-input:disabled~.form-file-label::after {
            background-color: var(--gray-300);
        }

        /* ===== INPUT GROUP ===== */
        .input-group {
            position: relative;
            display: flex;
            flex-wrap: wrap;
            align-items: stretch;
            width: 100%;
        }

        .input-group>.form-control,
        .input-group>.form-select {
            position: relative;
            flex: 1 1 auto;
            width: 1%;
            min-width: 0;
        }

        .input-group>.form-control:focus,
        .input-group>.form-select:focus {
            z-index: 3;
        }

        .input-group-text {
            display: flex;
            align-items: center;
            padding: 0.375rem 0.75rem;
            font-size: 1rem;
            font-weight: 400;
            line-height: 1.5;
            color: var(--gray-700);
            text-align: center;
            white-space: nowrap;
            background-color: var(--gray-200);
            border: 1px solid var(--gray-300);
            border-radius: 0.375rem;
        }

        .input-group-lg>.form-control,
        .input-group-lg>.form-select,
        .input-group-lg>.input-group-text {
            padding: 0.5rem 1rem;
            font-size: 1.25rem;
            border-radius: 0.5rem;
        }

        .input-group-sm>.form-control,
        .input-group-sm>.form-select,
        .input-group-sm>.input-group-text {
            padding: 0.25rem 0.5rem;
            font-size: 0.875rem;
            border-radius: 0.25rem;
        }

        .input-group:not(.has-validation)> :not(:last-child):not(.dropdown-toggle):not(.dropdown-menu),
        .input-group:not(.has-validation)>.dropdown-toggle:nth-last-child(n + 3) {
            border-top-right-radius: 0;
            border-bottom-right-radius: 0;
        }

        .input-group.has-validation> :nth-last-child(n + 3):not(.dropdown-toggle):not(.dropdown-menu),
        .input-group.has-validation>.dropdown-toggle:nth-last-child(n + 4) {
            border-top-right-radius: 0;
            border-bottom-right-radius: 0;
        }

        .input-group> :not(:first-child):not(.dropdown-menu):not(.valid-tooltip):not(.valid-feedback):not(.invalid-tooltip):not(.invalid-feedback) {
            margin-left: -1px;
            border-top-left-radius: 0;
            border-bottom-left-radius: 0;
        }

        /* ===== FLOATING LABELS ===== */
        .form-floating {
            position: relative;
        }

        .form-floating>.form-control,
        .form-floating>.form-select {
            height: calc(3.5rem + 2px);
            line-height: 1.25;
        }

        .form-floating>label {
            position: absolute;
            top: 0;
            left: 0;
            height: 100%;
            padding: 1rem 0.75rem;
            pointer-events: none;
            border: 1px solid transparent;
            transform-origin: 0 0;
            transition: opacity 0.1s ease-in-out, transform 0.1s ease-in-out;
        }

        .form-floating>.form-control::placeholder {
            color: transparent;
        }

        .form-floating>.form-control:focus,
        .form-floating>.form-control:not(:placeholder-shown) {
            padding-top: 1.625rem;
            padding-bottom: 0.625rem;
        }

        .form-floating>.form-control:focus~label,
        .form-floating>.form-control:not(:placeholder-shown)~label,
        .form-floating>.form-select~label {
            opacity: 0.65;
            transform: scale(0.85) translateY(-0.5rem) translateX(0.15rem);
        }

        .form-floating>.form-control:-webkit-autofill~label {
            opacity: 0.65;
            transform: scale(0.85) translateY(-0.5rem) translateX(0.15rem);
        }

        /* ===== VALIDATION ===== */
        .was-validated .form-control:valid,
        .form-control.is-valid {
            border-color: var(--success);
            padding-right: calc(1.5em + 0.75rem);
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 8 8'%3e%3cpath fill='%232ecc71' d='M2.3 6.73L.6 4.53c-.4-1.04.46-1.4 1.1-.8l1.1 1.4 3.4-3.8c.6-.63 1.6-.27 1.2.7l-4 4.6c-.43.5-.8.4-1.1.1z'/%3e%3c/svg%3e");
            background-repeat: no-repeat;
            background-position: right calc(0.375em + 0.1875rem) center;
            background-size: calc(0.75em + 0.375rem) calc(0.75em + 0.375rem);
        }

        .was-validated .form-control:valid:focus,
        .form-control.is-valid:focus {
            border-color: var(--success);
            box-shadow: 0 0 0 0.2rem rgba(46, 204, 113, 0.25);
        }

        .was-validated .form-control:invalid,
        .form-control.is-invalid {
            border-color: var(--danger);
            padding-right: calc(1.5em + 0.75rem);
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 12 12' width='12' height='12' fill='none' stroke='%23e74c3c'%3e%3ccircle cx='6' cy='6' r='4.5'/%3e%3cpath stroke-linejoin='round' d='M5.8 3.6h.4L6 6.5z'/%3e%3ccircle cx='6' cy='8.2' r='.6' fill='%23e74c3c' stroke='none'/%3e%3c/svg%3e");
            background-repeat: no-repeat;
            background-position: right calc(0.375em + 0.1875rem) center;
            background-size: calc(0.75em + 0.375rem) calc(0.75em + 0.375rem);
        }

        .was-validated .form-control:invalid:focus,
        .form-control.is-invalid:focus {
            border-color: var(--danger);
            box-shadow: 0 0 0 0.2rem rgba(231, 76, 60, 0.25);
        }

        .was-validated .form-select:valid,
        .form-select.is-valid {
            border-color: var(--success);
        }

        .was-validated .form-select:valid:not([multiple]):not([size]),
        .was-validated .form-select:valid:not([multiple])[size="1"],
        .form-select.is-valid:not([multiple]):not([size]),
        .form-select.is-valid:not([multiple])[size="1"] {
            padding-right: 4.125rem;
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3e%3cpath fill='none' stroke='%23343a40' stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='m2 5 6 6 6-6'/%3e%3c/svg%3e"), url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 8 8'%3e%3cpath fill='%232ecc71' d='M2.3 6.73L.6 4.53c-.4-1.04.46-1.4 1.1-.8l1.1 1.4 3.4-3.8c.6-.63 1.6-.27 1.2.7l-4 4.6c-.43.5-.8.4-1.1.1z'/%3e%3c/svg%3e");
            background-position: right 0.75rem center, center right 2.25rem;
            background-size: 16px 12px, calc(0.75em + 0.375rem) calc(0.75em + 0.375rem);
        }

        .was-validated .form-select:valid:focus,
        .form-select.is-valid:focus {
            border-color: var(--success);
            box-shadow: 0 0 0 0.2rem rgba(46, 204, 113, 0.25);
        }

        .was-validated .form-select:invalid,
        .form-select.is-invalid {
            border-color: var(--danger);
        }

        .was-validated .form-select:invalid:not([multiple]):not([size]),
        .was-validated .form-select:invalid:not([multiple])[size="1"],
        .form-select.is-invalid:not([multiple]):not([size]),
        .form-select.is-invalid:not([multiple])[size="1"] {
            padding-right: 4.125rem;
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3e%3cpath fill='none' stroke='%23343a40' stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='m2 5 6 6 6-6'/%3e%3c/svg%3e"), url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 12 12' width='12' height='12' fill='none' stroke='%23e74c3c'%3e%3ccircle cx='6' cy='6' r='4.5'/%3e%3cpath stroke-linejoin='round' d='M5.8 3.6h.4L6 6.5z'/%3e%3ccircle cx='6' cy='8.2' r='.6' fill='%23e74c3c' stroke='none'/%3e%3c/svg%3e");
            background-position: right 0.75rem center, center right 2.25rem;
            background-size: 16px 12px, calc(0.75em + 0.375rem) calc(0.75em + 0.375rem);
        }

        .was-validated .form-select:invalid:focus,
        .form-select.is-invalid:focus {
            border-color: var(--danger);
            box-shadow: 0 0 0 0.2rem rgba(231, 76, 60, 0.25);
        }

        .was-validated .form-check-input:valid,
        .form-check-input.is-valid {
            border-color: var(--success);
        }

        .was-validated .form-check-input:valid:checked,
        .form-check-input.is-valid:checked {
            background-color: var(--success);
        }

        .was-validated .form-check-input:valid:focus,
        .form-check-input.is-valid:focus {
            box-shadow: 0 0 0 0.25rem rgba(46, 204, 113, 0.25);
        }

        .was-validated .form-check-input:invalid,
        .form-check-input.is-invalid {
            border-color: var(--danger);
        }

        .was-validated .form-check-input:invalid:checked,
        .form-check-input.is-invalid:checked {
            background-color: var(--danger);
        }

        .was-validated .form-check-input:invalid:focus,
        .form-check-input.is-invalid:focus {
            box-shadow: 0 0 0 0.25rem rgba(231, 76, 60, 0.25);
        }

        .invalid-feedback {
            display: none;
            width: 100%;
            margin-top: 0.25rem;
            font-size: 0.875em;
            color: var(--danger);
        }

        .invalid-tooltip {
            position: absolute;
            top: 100%;
            z-index: 5;
            display: none;
            max-width: 100%;
            padding: 0.25rem 0.5rem;
            margin-top: 0.1rem;
            font-size: 0.875rem;
            color: #fff;
            background-color: rgba(231, 76, 60, 0.9);
            border-radius: 0.375rem;
        }

        .was-validated :invalid~.invalid-feedback,
        .was-validated :invalid~.invalid-tooltip,
        .is-invalid~.invalid-feedback,
        .is-invalid~.invalid-tooltip {
            display: block;
        }

        .valid-feedback {
            display: none;
            width: 100%;
            margin-top: 0.25rem;
            font-size: 0.875em;
            color: var(--success);
        }

        .valid-tooltip {
            position: absolute;
            top: 100%;
            z-index: 5;
            display: none;
            max-width: 100%;
            padding: 0.25rem 0.5rem;
            margin-top: 0.1rem;
            font-size: 0.875rem;
            color: #fff;
            background-color: rgba(46, 204, 113, 0.9);
            border-radius: 0.375rem;
        }

        .was-validated :valid~.valid-feedback,
        .was-validated :valid~.valid-tooltip,
        .is-valid~.valid-feedback,
        .is-valid~.valid-tooltip {
            display: block;
        }

        /* ===== CUSTOM FORMS ===== */
        .form-switch {
            padding-left: 2.5em;
        }

        .form-switch .form-check-input {
            width: 2em;
            margin-left: -2.5em;
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='-4 -4 8 8'%3e%3ccircle r='3' fill='rgba%280, 0, 0, 0.25%29'/%3e%3c/svg%3e");
            background-position: left center;
            border-radius: 2em;
            transition: background-position 0.15s ease-in-out;
        }

        .form-switch .form-check-input:focus {
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='-4 -4 8 8'%3e%3ccircle r='3' fill='%2386b7fe'/%3e%3c/svg%3e");
        }

        .form-switch .form-check-input:checked {
            background-position: right center;
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='-4 -4 8 8'%3e%3ccircle r='3' fill='%23fff'/%3e%3c/svg%3e");
        }

        .form-check-inline {
            display: inline-block;
            margin-right: 1rem;
        }

        .btn-check {
            position: absolute;
            clip: rect(0, 0, 0, 0);
            pointer-events: none;
        }

        .btn-check:disabled+.btn,
        .btn-check[disabled]+.btn {
            pointer-events: none;
            filter: none;
            opacity: 0.65;
        }

        /* ===== CUSTOM RANGE ===== */
        .form-range {
            width: 100%;
            height: 1.5rem;
            padding: 0;
            background-color: transparent;
            appearance: none;
        }

        .form-range:focus {
            outline: 0;
        }

        .form-range:focus::-webkit-slider-thumb {
            box-shadow: 0 0 0 1px #fff, 0 0 0 0.25rem rgba(13, 110, 253, 0.25);
        }

        .form-range:focus::-moz-range-thumb {
            box-shadow: 0 0 0 1px #fff, 0 0 0 0.25rem rgba(13, 110, 253, 0.25);
        }

        .form-range::-moz-focus-outer {
            border: 0;
        }

        .form-range::-webkit-slider-thumb {
            width: 1rem;
            height: 1rem;
            margin-top: -0.25rem;
            background-color: #0d6efd;
            border: 0;
            border-radius: 1rem;
            transition: background-color 0.15s ease-in-out, border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
            appearance: none;
        }

        .form-range::-webkit-slider-thumb:active {
            background-color: #b6d4fe;
        }

        .form-range::-webkit-slider-runnable-track {
            width: 100%;
            height: 0.5rem;
            color: transparent;
            cursor: pointer;
            background-color: var(--gray-300);
            border-color: transparent;
            border-radius: 1rem;
        }

        .form-range::-moz-range-thumb {
            width: 1rem;
            height: 1rem;
            background-color: #0d6efd;
            border: 0;
            border-radius: 1rem;
            transition: background-color 0.15s ease-in-out, border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
            appearance: none;
        }

        .form-range::-moz-range-thumb:active {
            background-color: #b6d4fe;
        }

        .form-range::-moz-range-track {
            width: 100%;
            height: 0.5rem;
            color: transparent;
            cursor: pointer;
            background-color: var(--gray-300);
            border-color: transparent;
            border-radius: 1rem;
        }

        .form-range:disabled {
            pointer-events: none;
        }

        .form-range:disabled::-webkit-slider-thumb {
            background-color: var(--gray-500);
        }

        .form-range:disabled::-moz-range-thumb {
            background-color: var(--gray-500);
        }

        /* ===== CUSTOM FILE INPUT ===== */
        .form-file {
            position: relative;
        }

        .form-file-input {
            position: relative;
            z-index: 2;
            width: 100%;
            height: calc(2.25rem + 2px);
            margin: 0;
            opacity: 0;
        }

        .form-file-label {
            position: absolute;
            top: 0;
            right: 0;
            left: 0;
            z-index: 1;
            height: calc(2.25rem + 2px);
            padding: 0.375rem 0.75rem;
            line-height: 1.5;
            color: var(--gray-700);
            background-color: #fff;
            border: 1px solid var(--gray-300);
            border-radius: 0.375rem;
        }

        .form-file-label::after {
            position: absolute;
            top: 0;
            right: 0;
            bottom: 0;
            z-index: 3;
            display: block;
            height: 100%;
            padding: 0.375rem 0.75rem;
            line-height: 1.5;
            color: var(--gray-700);
            content: "Browse";
            background-color: var(--gray-200);
            border-left: inherit;
            border-radius: 0 0.375rem 0.375rem 0;
        }

        .form-file-sm {
            height: calc(1.875rem + 2px);
        }

        .form-file-lg {
            height: calc(2.875rem + 2px);
        }

        .form-file-input:focus~.form-file-label {
            border-color: #86b7fe;
            box-shadow: 0 0 0 0.25rem rgba(13, 110, 253, 0.25);
        }

        .form-file-input:disabled~.form-file-label {
            background-color: var(--gray-200);
        }

        .form-file-input:disabled~.form-file-label::after {
            background-color: var(--gray-300);
        }

        /* ===== INPUT GROUP ===== */
        .input-group {
            position: relative;
            display: flex;
            flex-wrap: wrap;
            align-items: stretch;
            width: 100%;
        }

        .input-group>.form-control,
        .input-group>.form-select {
            position: relative;
            flex: 1 1 auto;
            width: 1%;
            min-width: 0;
        }

        .input-group>.form-control:focus,
        .input-group>.form-select:focus {
            z-index: 3;
        }

        .input-group-text {
            display: flex;
            align-items: center;
            padding: 0.375rem 0.75rem;
            font-size: 1rem;
            font-weight: 400;
            line-height: 1.5;
            color: var(--gray-700);
            text-align: center;
            white-space: nowrap;
            background-color: var(--gray-200);
            border: 1px solid var(--gray-300);
            border-radius: 0.375rem;
        }

/* Navbar */
.navbar {
  width: 100%;
  background: #222;        /* background color */
  padding: 0.75rem 1.5rem;
  border-bottom: 2px solid #333;
  position: sticky;
  top: 0;
  z-index: 100;
  margin-top: -30px;
  width: 1355px;
}

.nav-left {
  display: flex;
  align-items: center;
  gap: 1.5rem;             /* space between logo + buttons */
}

.nav-logo {
  height: 40px;
  width: auto;
  cursor: pointer;
}

.nav-link {
  color: #f0f0f0;
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s ease;
}

.nav-link:hover {
  color: #4cafef;          /* highlight blue on hover */
}


/* Donation Page */
.qr-image {
    border-radius: 20px;
}

/* OTHERS */
.crypto-list {
    list-style-type: none;
}