@media (max-width: 768px) {
    :root {
        --header-height: 56px;
    }

    #main {
        padding: var(--spacing-4) var(--spacing-3);
    }

    .exercise-question {
        padding: var(--spacing-6);
    }

    .question-math .katex {
        font-size: 1.25em;
    }

    .answer-input {
        width: 160px;
        font-size: var(--font-size-lg);
    }

    .fraction-input-container .fraction-numerator,
    .fraction-input-container .fraction-denominator {
        width: 60px;
        font-size: var(--font-size-lg);
    }

    .fraction-input-container .fraction-line {
        width: 70px;
    }

    .scaffold-step {
        flex-direction: column;
        gap: var(--spacing-2);
    }

    .progress-stats {
        grid-template-columns: 1fr;
    }

    .session-summary {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .exercise-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .exercise-question {
        padding: var(--spacing-4);
    }

    .answer-input-container {
        flex-direction: column;
    }

    .combined-answer-input {
        flex-direction: column;
    }

    .answer-input {
        width: 100%;
        max-width: 200px;
    }

    .exercise-actions {
        flex-direction: column;
    }

    .exercise-actions .btn {
        width: 100%;
    }
}

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
    }
}