@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700;900&display=swap');
        body {
            font-family: 'Inter', sans-serif;
            background-color: #f7f9fc; /* Light, clean background */
        }
        .main-container {
            min-height: calc(100vh - 4rem);
            padding-bottom: 5rem;
        }
        .card-active-shadow {
            box-shadow: 0 8px 15px rgba(239, 68, 68, 0.15);
        }
        .performance-badge {
            font-weight: 700;
            padding: 2px 8px;
            border-radius: 9999px;
            text-transform: uppercase;
            font-size: 0.65rem;
        }
        .badge-elite { background-color: #fca5a5; color: #991b1b; } /* Red */
        .badge-pro { background-color: #93c5fd; color: #1e40af; } /* Blue */
        .badge-comfort { background-color: #a7f3d0; color: #065f46; } /* Green */

        /* Custom checked state for size labels */
        input[type="radio"]:checked + label {
            background-color: #ef4444; /* Red-500 */
            color: white;
            border-color: #ef4444;
        }