:root {
            --primary-color: #2c7da0;
            --secondary-color: #a9d6e5;
            --accent-color: #01497c;
            --light-gray: #f8f9fa;
            --border-color: #eaeaea;
            --text-color: #333;
            --text-muted: #6c757d;
            --success-color: #28a745;
            --warning-color: #ffc107;
            --math-color: #6f42c1;
            --calc-color: #e83e8c;
        }
       .page-header {
            background: linear-gradient(135deg, rgba(169, 214, 229, 0.4) 0%, rgba(44, 125, 160, 0.4) 100%);
            padding: 1.5rem 0;
            margin-bottom: 2rem;
            border-bottom: 1px solid rgba(44, 125, 160, 0.2);
            position: relative;
            overflow: hidden;   color: var(--text-color);
        }
        .breadcrumb {
            background-color: transparent;
            padding: 0.5rem 0;
            margin-bottom: 0.5rem;
        }
        .breadcrumb-item a {
            color: var(--text-muted);
            text-decoration: none;
        }
        .breadcrumb-item.active {
            color: var(--text-color);
        }
        .form-control:focus {
            border-color: var(--primary-color);
            box-shadow: 0 0 0 3px rgba(44, 125, 160, 0.15);
        }
        .color-input-group {
            display: flex;
            align-items: center;
            gap: 10px;
        }
        .color-preview-box {
            width: 60px;
            height: 50px;
            border: 1px solid #ddd;
            border-radius: 6px;
            cursor: pointer;
        }
        .color-preview-large {
            width: 100%;
            height: 120px;
            border-radius: 8px;
            border: 2px solid white;
            box-shadow: 0 2px 8px rgba(0,0,0,0.1);
            margin: 15px 0;
            transition: background-color 0.2s;
        }
        .math-result {
            padding: 12px;
            background-color: white;
            border-radius: 4px;
            border: 1px solid #eee;
            font-size: 1.1rem;
            font-family: 'Courier New', monospace;
            margin: 10px 0;
            text-align: center;
        }
        .hsv-value {
            font-size: 1.2rem;
            font-weight: 600;
            color: var(--accent-color);
        }
        .color-swatch-grid {
            display: flex;
            flex-wrap: wrap;
            gap: 0.5rem;
            margin: 1rem 0;
        }
        .swatch-item {
            width: 40px;
            height: 40px;
            border-radius: 4px;
            border: 1px solid #ddd;
            cursor: pointer;
            transition: transform 0.1s;
        }
        .swatch-item:hover {
            transform: scale(1.1);
            border-color: var(--primary-color);
        }
        .math-box {
            background-color: rgba(111, 66, 193, 0.05);
            border-left: 3px solid var(--math-color);
            padding: 1rem;
            border-radius: 0 4px 4px 0;
            margin: 1.5rem 0;
        }
        @media (max-width: 768px) {
            }
        .color-examples {
            display: flex;
            flex-wrap: wrap;
            gap: 0.5rem;
            margin: 1rem 0;
        }
        .example-swatch {
            width: 50px;
            height: 50px;
            border-radius: 6px;
            border: 2px solid transparent;
            transition: all 0.2s;
            cursor: pointer;
            box-shadow: 0 2px 5px rgba(0,0,0,0.1);
        }
        .example-swatch:hover {
            transform: scale(1.1);
            border-color: var(--primary-color);
        }