@media (max-width: 1180px) {
    .app-shell {
        grid-template-columns: 1fr;
        position: relative;
    }

    .app-shell.menu-open {
        overflow: hidden;
    }

    .sidebar {
        position: fixed;
        top: 0;
        left: 0;
        width: min(340px, 88vw);
        height: 100vh;
        padding: 22px 18px;
        transform: translateX(-105%);
        transition: transform 180ms ease;
        z-index: 15;
        overflow-y: auto;
    }

    .app-shell.menu-open .sidebar {
        transform: translateX(0);
    }

    .sidebar-header {
        display: flex;
    }

    .sidebar-brand {
        display: none;
    }

    .sidebar-toggle {
        display: inline-grid;
        place-items: center;
        align-self: flex-start;
    }

    .sidebar-close {
        display: grid;
    }

    .sidebar-backdrop[hidden] {
        display: none;
    }

    .topbar {
        position: sticky;
        top: 0;
        z-index: 9;
        padding: 10px 0 4px;
        background: rgba(244, 241, 234, 0.9);
        backdrop-filter: blur(14px);
    }

    .topbar-heading {
        align-items: flex-start;
        flex: 1;
    }

    .topbar-actions {
        justify-content: flex-end;
    }

    .app-content {
        padding: 22px;
        gap: 18px;
    }

    .panel {
        padding: 20px;
    }

    .stats-grid,
    .preview-panel,
    .proof-correction-paths,
    .proof-stat-strip,
    .version-grid,
    .camera-summary-grid,
    .student-picker-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .columns-4,
    .columns-5 {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .proof-hero {
        grid-template-columns: 1fr;
    }

    .proof-side-actions {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .proof-side-actions .btn {
        width: 100%;
    }

    .table-wrap {
        margin: 0 -4px;
        padding: 0 4px 8px;
        overflow-x: auto;
        overflow-y: hidden;
        -webkit-overflow-scrolling: touch;
        scrollbar-width: thin;
        touch-action: pan-x;
    }

    .data-table {
        min-width: 720px;
    }

    .exam-sheet {
        width: min(100%, 210mm);
        margin: 14px auto 32px;
        padding: 12mm;
    }

    .exam-header {
        grid-template-columns: minmax(0, 1fr) 160px;
    }

    .omr-response-zone {
        padding: 18px 22px;
    }
}

@media (max-width: 920px) {
    .auth-body,
    .app-content {
        padding: 18px;
    }

    .panel-row,
    .section-heading-inline,
    .proof-header-grid,
    .version-card-header,
    .question-title-row {
        flex-direction: column;
        align-items: flex-start;
    }

    .columns-2,
    .columns-3,
    .columns-4,
    .columns-5,
    .preview-panel,
    .proof-correction-paths,
    .proof-stat-strip,
    .version-grid,
    .stats-grid,
    .camera-summary-grid,
    .student-picker-grid,
    .exam-header,
    .exam-detail-list,
    .exam-summary-grid,
    .enumere-grid,
    .omr-sheet-header,
    .omr-sheet-meta {
        grid-template-columns: 1fr;
    }

    .button-row {
        width: 100%;
    }

    .button-row .btn,
    .form-actions .btn {
        flex: 1 1 220px;
    }

    .topbar {
        align-items: flex-start;
    }

    .topbar-actions {
        width: 100%;
        justify-content: flex-start;
    }

    .topbar-user {
        max-width: 100%;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
    }

    .version-actions-grid,
    .answer-card-grid,
    .proof-side-actions,
    .type-selection-grid {
        grid-template-columns: 1fr;
    }

    .proof-side-actions {
        width: 100%;
    }

    .performance-row {
        grid-template-columns: 1fr;
        gap: 10px;
    }

    .data-table {
        min-width: 660px;
    }

    .omr-table-grid {
        flex-direction: column;
        gap: 18px;
    }

    .omr-table {
        width: 100%;
        max-width: none;
    }
}

@media (max-width: 768px) {
    .panel {
        padding: 18px;
        border-radius: 20px;
    }

    .app-content {
        padding: 16px;
    }

    .topbar h1 {
        font-size: clamp(1.55rem, 6vw, 2.1rem);
    }

    .btn,
    input,
    select,
    textarea {
        min-height: 50px;
    }

    .btn {
        width: 100%;
    }

    .button-row .btn,
    .form-actions .btn {
        flex: 1 1 100%;
    }

    .proof-showcase,
    .panel-intro {
        padding: 18px;
    }

    .proof-stat-card,
    .summary-box,
    .preview-card,
    .proof-meta-box,
    .hint-box {
        padding: 14px;
    }

    .data-table {
        min-width: 600px;
    }

    .exam-sheet {
        width: calc(100% - 12px);
        padding: 16px;
        margin: 8px auto 24px;
        border-radius: 16px;
    }

    .print-toolbar {
        padding: 12px;
        flex-wrap: wrap;
    }

    .omr-response-zone {
        padding: 16px 18px;
    }
}

@media (max-width: 640px) {
    .auth-body {
        padding: 18px;
    }

    .login-card {
        grid-template-columns: 1fr;
    }

    .login-copy {
        min-height: 300px;
        padding: 28px;
    }

    .sidebar {
        width: min(320px, 92vw);
    }

    .topbar-heading {
        width: 100%;
    }

    .sidebar-toggle {
        margin-bottom: 8px;
    }

    .table-wrap {
        margin: 0 -8px;
        padding: 0 8px 8px;
    }

    .data-table {
        min-width: 560px;
    }
}

@media (orientation: portrait) and (max-width: 1180px) {
    .topbar {
        padding-top: 6px;
    }
}

@media (orientation: landscape) and (max-width: 1180px) {
    .sidebar {
        width: min(360px, 56vw);
    }
}