@media (max-width: 900px) {
    .lesson-shell .header {
        flex-direction: column;
        align-items: flex-start;
        gap: 16px;
    }

    .lesson-shell .stats {
        width: 100%;
        justify-content: space-between;
        flex-wrap: wrap;
        gap: 10px;
    }

    .lesson-shell .xp-cluster {
        width: 100%;
        flex-direction: column;
        align-items: stretch;
        gap: 10px;
    }

    .lesson-shell .progress-pills {
        width: 100%;
        flex-direction: column;
        align-items: stretch;
        gap: 8px;
    }

    .lesson-shell .mode-selector,
    .lesson-shell .mode-toggle {
        width: 100%;
        flex-wrap: wrap;
        justify-content: center;
    }

    .lesson-shell .mode-btn {
        flex: 1 1 48%;
        min-width: 140px;
    }

    .lesson-shell .prompt-compare {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 700px) {
    .lesson-shell .challenge-title {
        font-size: 28px;
    }

    .lesson-shell .activity-card,
    .lesson-shell .learning-card,
    .lesson-shell .story-card,
    .lesson-shell .card,
    .lesson-shell .panel {
        padding: 18px;
    }

    .lesson-shell .word-options {
        grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
        gap: 10px;
    }

    .lesson-shell .voice-grid,
    .lesson-shell .content-grid,
    .lesson-shell .learning-showcase {
        display: flex;
        flex-direction: column;
        gap: 16px;
    }

    .lesson-shell .chat-controls {
        flex-direction: column;
        align-items: stretch;
    }

    .lesson-shell .chat-controls select,
    .lesson-shell .chat-controls button {
        width: 100%;
    }

    .lesson-shell .story-card {
        min-height: auto;
    }

    .lesson-shell .step-selector {
        flex-direction: column;
    }

    .lesson-shell .step-pill {
        width: 100%;
    }
}

@media (max-width: 520px) {
    .lesson-shell .challenge-title {
        font-size: 24px;
    }

    .lesson-shell .mode-btn {
        flex: 1 1 100%;
        min-width: 0;
    }

    .lesson-shell .activity-card,
    .lesson-shell .learning-card,
    .lesson-shell .story-card,
    .lesson-shell .self-checklist,
    .lesson-shell .card,
    .lesson-shell .panel {
        padding: 14px;
    }

    .lesson-shell .word-options {
        grid-template-columns: 1fr;
    }

    .lesson-shell .tone-word-bank,
    .lesson-shell .path-steps,
    .lesson-shell .mission-checklist {
        gap: 8px;
    }

    .lesson-shell .progress-pills .progress-pill {
        text-align: center;
    }
}