: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;
            --danger-color: #dc3545;
            --crypto-color: #6f42c1;
        }.breadcrumb-item.active{color:#333}
         .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:#333
        }
        .breadcrumb {
            background-color: transparent;
            padding: 0.5rem 0;
            margin-bottom: 0.5rem;
        }
        .breadcrumb-item a {
            color: var(--text-muted);
            text-decoration: none;
        }
        .crypto-output {
            background-color: white;
            border: 1px solid #eee;
            border-radius: 4px;
            padding: 1rem;
            font-family: 'Courier New', monospace;
            word-break: break-all;
            margin: 10px 0;
            max-height: 200px;
            overflow-y: auto;
        }
        .crypto-box {
            background-color: rgba(111, 66, 193, 0.05);
            border-left: 3px solid var(--crypto-color);
            padding: 1rem;
            border-radius: 0 4px 4px 0;
            margin: 1.5rem 0;
        }
        .example-btn {
            background-color: rgba(44, 125, 160, 0.1);
            border: 1px solid rgba(44, 125, 160, 0.2);
            border-radius: 4px;
            padding: 0.5rem 0.75rem;
            font-size: 0.9rem;
            color: var(--primary-color);
            cursor: pointer;
            transition: all 0.2s;
            font-family: 'Courier New', monospace;
        }
        .example-btn:hover {
            background-color: rgba(44, 125, 160, 0.2);
            transform: translateY(-2px);
        }
        .key-length-warning {
            font-size: 0.85rem;
            color: var(--danger-color);
        }
        .mode-description {
            font-size: 0.9rem;
            color: var(--text-muted);
            margin-top: 0.25rem;
        }
        .iv-container {
            display: none;
        }
        .feistel-figure {
            background-color: #f1f3f5;
            padding: 1rem;
            border-radius: 8px;
            text-align: center;
            margin: 1rem 0;
        }
        .feistel-figure pre {
            background: #2d2d2d;
            color: #fff;
            padding: 0.5rem;
            border-radius: 4px;
            display: inline-block;
        }
        .citation {
            font-size: 0.85rem;
            color: var(--text-muted);
            margin-top: 0.5rem;
            border-top: 1px dashed var(--border-color);
            padding-top: 0.5rem;
        }