.speed-metric {
            background: white;
            border-radius: 12px;
            padding: 1.2rem;
            box-shadow: 0 2px 8px rgba(0,0,0,0.05);
            margin-bottom: 1rem;
            transition: all 0.2s;
        }
        .metric-value {
            font-size: 2rem;
            font-weight: 700;
            color: #0d6efd;
            line-height: 1.2;
        }
        .grade-A { background-color: #d4edda; color: #155724; border-left: 5px solid #28a745; }
        .grade-B { background-color: #fff3cd; color: #856404; border-left: 5px solid #ffc107; }
        .grade-C { background-color: #f8d7da; color: #721c24; border-left: 5px solid #dc3545; }
        .test-loader {
            display: inline-block;
            width: 1.5rem;
            height: 1.5rem;
            border: 3px solid rgba(13,110,253,0.3);
            border-radius: 50%;
            border-top-color: #0d6efd;
            animation: spin 1s ease-in-out infinite;
        }
        @keyframes spin { to { transform: rotate(360deg); } }
        .result-details {
            font-family: 'SF Mono', 'Courier New', monospace;
            font-size: 0.9rem;
            background-color: #f8f9fc;
            padding: 1rem;
            border-radius: 8px;
        }
        .insight-badge {
            background-color: #e9ecef;
            padding: 0.25rem 0.75rem;
            border-radius: 20px;
            font-size: 0.8rem;
            display: inline-block;
            margin-right: 0.5rem;
            margin-bottom: 0.5rem;
        }
        .example-url {
            cursor: pointer;
            transition: 0.1s;
        }
        .example-url:hover {
            background-color: rgba(13,110,253,0.1);
            text-decoration: underline;
        }
        .btn-test {
            min-width: 140px;
        }
        footer {
            background: #f1f3f5;
            padding: 1.5rem 0;
            margin-top: 2rem;
            text-align: center;
            color: #6c757d;
        }