.preview-card {
            background: rgba(255, 255, 255, 0.25);
            backdrop-filter: blur(10px);
            border-radius: 28px;
            border: 1px solid rgba(255,255,255,0.3);
            box-shadow: 0 8px 32px rgba(0,0,0,0.1);
            transition: all 0.1s ease;
            padding: 2rem;
            text-align: center;
            color: #1e2a3a;
        }
        .preview-card h3 {
            font-weight: 600;
            margin-bottom: 1rem;
        }
        .preview-card p {
            font-size: 1rem;
            opacity: 0.9;
        }
        .demo-bg-area {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            border-radius: 28px;
            min-height: 380px;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: background 0.2s;
            box-shadow: 0 12px 28px rgba(0,0,0,0.1);
        }
        .code-block {
            background-color: #1e293b;
            color: #e2e8f0;
            padding: 1.2rem;
            border-radius: 16px;
            font-family: 'Fira Code', 'Courier New', monospace;
            font-size: 0.85rem;
            white-space: pre-wrap;
            word-break: break-all;
            margin-top: 1rem;
            border-left: 4px solid #3b82f6; text-align:left;max-height:300px;overflow:auto
        }
        .control-group {
            background-color: #f8fafc;
            border-radius: 20px;
            padding: 1.2rem;
            margin-bottom: 1.5rem;
            border: 1px solid #e2e8f0;
        }
        .slider-label {
            font-weight: 500;
            margin-bottom: 0.3rem;
        }
        .gradient-preview {
            width: 100%;
            height: 40px;
            border-radius: 12px;
            margin-top: 8px;
            border: 1px solid #cbd5e1;
        }
        .img-thumb-preview {
            max-width: 100%;
            max-height: 60px;
            border-radius: 12px;
            object-fit: cover;
            margin-top: 8px;
        }
        .mode-selector .btn-check:checked+.btn {
            background-color: #3b82f6;
            color: white;
            border-color: #3b82f6;
        }
        .mode-selector .btn {
            border-radius: 40px;
            padding: 0.3rem 0.5rem;
        }
        .result-card {
            background: white;
            border-radius: 24px;
            padding: 1.2rem;
            box-shadow: 0 2px 10px rgba(0,0,0,0.03);
        }
        .feature-icon {
            font-size: 1.8rem;
            color: #3b82f6;
            margin-right: 0.75rem;
        }
        .case-study-card {
            background: #f1f5f9;
            border-radius: 20px;
            padding: 1.5rem;
            margin: 1.5rem 0;
            border-left: 5px solid #3b82f6;
        }
        .authority-badge {
            background: #e6f7ff;
            border-radius: 40px;
            padding: 0.2rem 1rem;
            display: inline-block;
            font-size: 0.8rem;
        }
        .legend-color-square {
            width: 20px;
            height: 20px;
            border-radius: 6px;
            display: inline-block;
            margin-right: 6px;
        }
        @media (max-width: 768px) {
            .preview-card { padding: 1.2rem; }
            .demo-bg-area { min-height: 280px; }
        }
        .additional-controls {
            background: white;
            border-radius: 16px;
            padding: 0.75rem;
            border: 1px solid #e2e8f0;
            margin-top: 0.75rem;
        }
        .code-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 0.5rem;
        }
        .copy-feedback {
            font-size: 0.8rem;
            transition: opacity 0.2s;
        }