/* Responsive – toàn bộ dự án */

@media (max-width: 768px) {
    .header-inner {
        flex-wrap: wrap;
        gap: 12px;
    }

    .nav {
        flex-wrap: wrap;
        width: 100%;
        justify-content: flex-start;
    }

    .container {
        padding: 0 16px;
    }

    .main {
        padding: 20px 0 32px;
    }

    .hero {
        padding: 32px 16px;
    }

    .hero h1 {
        font-size: 20px;
    }

    .quiz-grid {
        grid-template-columns: 1fr;
    }

    .admin-stats {
        grid-template-columns: repeat(2, 1fr);
    }

    .table-responsive {
        font-size: 13px;
    }

    .table th,
    .table td {
        padding: 10px 12px;
    }

    .table td .btn-sm {
        display: inline-block;
        margin-bottom: 4px;
    }

    .answer-row {
        flex-direction: column;
        align-items: flex-start;
    }

    .answer-row input[type="text"] {
        width: 100%;
    }

    .form-card,
    .form-card.form-card--wide {
        max-width: 100%;
    }
}

@media (max-width: 480px) {
    .container > h1,
    .page-title {
        font-size: 18px;
    }

    .quiz-do h1 {
        font-size: 18px;
    }

    .stat-card h3 {
        font-size: 22px;
    }

    .auth-box {
        padding: 24px 20px;
    }
}