/* ═══════════════════════════════════════
   TOKENS
═══════════════════════════════════════ */
:root {
    --bg: #0C0E14;
    --bg2: #12151E;
    --bg3: #191D28;
    --surface: #1F2435;
    --surface2: #262D42;
    --border: rgba(255, 255, 255, 0.06);
    --border2: rgba(255, 255, 255, 0.11);

    --text1: #EDF0FA;
    --text2: #8B93B0;
    --text3: #4E566E;

    --blue: #3B82F6;
    --blue-d: #2563EB;
    --blue-bg: rgba(59, 130, 246, 0.10);
    --blue-bd: rgba(59, 130, 246, 0.25);

    --indigo: #818CF8;
    --indigo-bg: rgba(129, 140, 248, 0.10);
    --indigo-bd: rgba(129, 140, 248, 0.25);

    --green: #34D399;
    --green-d: #10B981;
    --green-bg: rgba(52, 211, 153, 0.10);
    --green-bd: rgba(52, 211, 153, 0.25);

    --teal: #22D3EE;
    --teal-bg: rgba(34, 211, 238, 0.10);
    --teal-bd: rgba(34, 211, 238, 0.25);

    --amber: #FBBF24;
    --amber-bg: rgba(251, 191, 36, 0.10);
    --amber-bd: rgba(251, 191, 36, 0.25);

    --red: #F87171;
    --red-bg: rgba(248, 113, 113, 0.10);

    --sidebar-w: 224px;
    --r: 10px;
    --r-sm: 7px;
}

/* ═══════════════════════════════════════
     RESET
  ═══════════════════════════════════════ */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 14px;
    scroll-behavior: smooth;
}

body {
    font-family: 'Sora', sans-serif;
    background: var(--bg);
    color: var(--text1);
    display: flex;
    min-height: 100vh;
    overflow-x: hidden;
}

/* ═══════════════════════════════════════
     SIDEBAR
  ═══════════════════════════════════════ */
.sidebar {
    width: var(--sidebar-w);
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    background: var(--bg2);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    z-index: 200;
}

.sidebar-top {
    padding: 20px 16px 16px;
    border-bottom: 1px solid var(--border);
}

.brand {
    display: flex;
    align-items: center;
    gap: 10px;
}

.brand-mark {
    width: 34px;
    height: 34px;
    border-radius: 8px;
    background: var(--blue-bg);
    border: 1px solid var(--blue-bd);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--blue);
    flex-shrink: 0;
}

.brand-text {
    display: flex;
    flex-direction: column;
    line-height: 1;
}

.brand-name {
    font-size: 13px;
    font-weight: 700;
    color: var(--text1);
}

.brand-tag {
    font-size: 10px;
    font-weight: 500;
    color: var(--blue);
    letter-spacing: .08em;
    margin-top: 2px;
}

.nav {
    flex: 1;
    padding: 16px 10px;
}

.nav-section-label {
    font-size: 10px;
    font-weight: 600;
    letter-spacing: .12em;
    color: var(--text3);
    padding: 0 8px;
    margin-bottom: 8px;
}

.nav-btn {
    display: flex;
    align-items: center;
    gap: 9px;
    width: 100%;
    padding: 9px 10px;
    border: 1px solid transparent;
    background: transparent;
    color: var(--text2);
    font-family: 'Sora', sans-serif;
    font-size: 12.5px;
    font-weight: 500;
    border-radius: var(--r-sm);
    cursor: pointer;
    transition: all .17s ease;
    margin-bottom: 3px;
}

.nav-btn:hover {
    background: var(--surface);
    color: var(--text1);
}

.nav-btn.active {
    background: var(--blue-bg);
    color: var(--blue);
    border-color: var(--blue-bd);
}

.nav-btn-icon {
    display: flex;
    align-items: center;
    flex-shrink: 0;
}

.nav-btn-label {
    flex: 1;
    text-align: left;
}

.pill {
    font-size: 10px;
    font-weight: 700;
    padding: 2px 7px;
    border-radius: 20px;
    flex-shrink: 0;
}

.pill.blue {
    background: var(--blue-bg);
    color: var(--blue);
}

.pill.green {
    background: var(--green-bg);
    color: var(--green);
}

.sidebar-bottom {
    padding: 14px 16px;
    border-top: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.conn-status {
    display: flex;
    align-items: center;
    gap: 7px;
}

.conn-dot {
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: var(--text3);
    flex-shrink: 0;
    transition: background .3s;
}

.conn-dot.ok {
    background: var(--green);
    box-shadow: 0 0 5px var(--green);
}

.conn-dot.busy {
    background: var(--amber);
    animation: blink 1s infinite;
}

.conn-dot.error {
    background: var(--red);
}

.conn-label {
    font-size: 11px;
    color: var(--text3);
}

.version-tag {
    font-size: 10px;
    color: var(--text3);
    font-family: 'JetBrains Mono', monospace;
}

@keyframes blink {

    0%,
    100% {
        opacity: 1
    }

    50% {
        opacity: .3
    }
}

/* ═══════════════════════════════════════
     MAIN
  ═══════════════════════════════════════ */
.main {
    margin-left: var(--sidebar-w);
    flex: 1;
    padding: 28px 32px;
    min-height: 100vh;
}

/* ── Disabled scan button wrapper ───────────────── */
.scan-btn-wrap {
    position: relative;
    display: inline-block;
    width: 100%;
}

.scan-btn-wrap .btn:disabled {
    pointer-events: none;
    /* let the wrapper catch hover */
}

/* The tooltip bubble */
.scan-btn-wrap::after {
    content: attr(data-tip);
    position: absolute;
    bottom: calc(100% + 8px);
    left: 50%;
    transform: translateX(-50%) translateY(4px);
    background: var(--surface2, #1e2030);
    color: var(--text1, #e2e8f0);
    font-size: 11.5px;
    font-family: 'Sora', sans-serif;
    white-space: nowrap;
    padding: 6px 11px;
    border-radius: 7px;
    border: 1px solid var(--border, rgba(255, 255, 255, 0.08));
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.35);
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.18s ease, transform 0.18s ease;
    z-index: 50;
}

/* Arrow */
.scan-btn-wrap::before {
    content: '';
    position: absolute;
    bottom: calc(100% + 2px);
    left: 50%;
    transform: translateX(-50%) translateY(4px);
    border: 5px solid transparent;
    border-top-color: var(--surface2, #1e2030);
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.18s ease, transform 0.18s ease;
    z-index: 51;
}

.scan-btn-wrap:has(.btn:disabled):hover::after {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

.scan-btn-wrap:has(.btn:disabled):hover::before {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

/* ═══════════════════════════════════════
     PANELS
  ═══════════════════════════════════════ */
.panel {
    display: none;
}

.panel.active {
    display: block;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(8px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ═══════════════════════════════════════
     PAGE HEADER
  ═══════════════════════════════════════ */
.page-hdr {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 16px;
    margin-bottom: 26px;
}

.page-hdr-left h1 {
    font-size: 20px;
    font-weight: 700;
    color: var(--text1);
}

.page-hdr-left p {
    font-size: 12.5px;
    color: var(--text2);
    margin-top: 3px;
}

.page-hdr-right {
    display: flex;
    align-items: center;
    gap: 10px;
}

/* ═══════════════════════════════════════
     GRID
  ═══════════════════════════════════════ */
.grid-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 14px;
    margin-bottom: 26px;
}

@media (max-width: 860px) {
    .grid-2 {
        grid-template-columns: 1fr;
    }
}

/* ═══════════════════════════════════════
     CARDS
  ═══════════════════════════════════════ */
.card {
    background: var(--bg2);
    border: 1px solid var(--border);
    border-radius: var(--r);
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 14px;
    transition: border-color .2s, box-shadow .2s;
}

.card:hover {
    border-color: var(--border2);
    box-shadow: 0 6px 28px rgba(0, 0, 0, .35);
}

.card-hd {
    display: flex;
    flex-direction: row;
    align-items: center;
    gap: 12px;
}

.card-hd>div h3 {
    font-size: 15px;
    font-weight: 700;
    color: var(--text1);
    margin-bottom: 4px;
}

.card-hd>div p {
    font-size: 12px;
    color: var(--text2);
    line-height: 1.5;
}

.card-icon {
    width: 44px;
    height: 44px;
    flex-shrink: 0;
    border-radius: var(--r-sm);
    display: flex;
    align-items: center;
    justify-content: center;
}

.card-icon.blue {
    background: var(--blue-bg);
    color: var(--blue);
    border: 1px solid var(--blue-bd);
}

.card-icon.indigo {
    background: var(--indigo-bg);
    color: var(--indigo);
    border: 1px solid var(--indigo-bd);
}

.card-icon.green {
    background: var(--green-bg);
    color: var(--green);
    border: 1px solid var(--green-bd);
}

.card-icon.teal {
    background: var(--teal-bg);
    color: var(--teal);
    border: 1px solid var(--teal-bd);
}

.card-icon.amber {
    background: var(--amber-bg);
    color: var(--amber);
    border: 1px solid var(--amber-bd);
}

/* ═══════════════════════════════════════
     UPLOAD ZONE
  ═══════════════════════════════════════ */
.upload-zone {
    border: 1.5px dashed var(--border2);
    border-radius: var(--r-sm);
    transition: border-color .2s, background .2s;
}

.upload-zone.drag-over {
    border-color: var(--blue);
    background: var(--blue-bg);
}

.upload-zone-inner {
    padding: 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    color: var(--text3);
}

.upload-zone-inner:hover {
    color: var(--text2);
}

.upload-zone-text {
    font-size: 12.5px;
}

.upload-zone-text u {
    color: var(--blue);
}

.upload-zone-sub {
    font-size: 11px;
    color: var(--text3);
    font-family: 'JetBrains Mono', monospace;
}


/* Set selector tabs (Answer Key card) */
.set-tabs {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
}

.set-tab {
    font-size: 12px;
    font-weight: 600;
    padding: 5px 14px;
    border-radius: 7px;
    border: 1.5px solid var(--border, #2e3449);
    background: transparent;
    color: var(--text3, #6b7280);
    cursor: pointer;
    transition: border-color 0.15s, color 0.15s, background 0.15s;
    font-family: inherit;
}

.set-tab:hover {
    border-color: #f59e0b;
    color: #f59e0b;
}

.set-tab.active {
    background: rgba(251, 191, 36, 0.12);
    border-color: #f59e0b;
    color: #f59e0b;
}

/* ═══════════════════════════════════════
     PROGRESS PANEL
  ═══════════════════════════════════════ */
.progress-panel {
    background: var(--bg2);
    border: 1px solid var(--border2);
    border-radius: var(--r);
    margin-bottom: 24px;
    overflow: hidden;
}

.progress-hdr {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 18px;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
}

.progress-title {
    display: flex;
    align-items: center;
    gap: 9px;
    font-size: 12px;
    font-weight: 600;
    color: var(--text2);
}

.live-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--green);
    box-shadow: 0 0 6px var(--green);
    animation: blink 1s infinite;
}

.progress-meta {
    font-family: 'JetBrains Mono', monospace;
    font-size: 12px;
    color: var(--text3);
}

.progress-bar-wrap {
    height: 3px;
    background: var(--surface2);
}

.progress-bar {
    height: 100%;
    background: var(--blue);
    transition: width .3s ease;
}

.progress-log {
    padding: 12px 18px;
    max-height: 180px;
    overflow-y: auto;
    font-family: 'JetBrains Mono', monospace;
    font-size: 11.5px;
    color: var(--text2);
    line-height: 1.9;
}

.progress-log .pf {
    color: var(--blue);
    font-weight: 600;
}

.progress-log .pid {
    color: var(--teal);
}

.progress-log .psc {
    color: var(--amber);
}

.progress-log .ps {
    color: var(--green);
}

.progress-log .pe {
    color: var(--red);
}

.progress-log .pd {
    color: var(--indigo);
}

.progress-footer {
    padding: 10px 18px;
    border-top: 1px solid var(--border);
    display: flex;
    gap: 10px;
    align-items: center;
}

/* ═══════════════════════════════════════
     SECTION BAR + TABLE
  ═══════════════════════════════════════ */
.section-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 12px;
}

.section-ttl {
    font-size: 14px;
    font-weight: 600;
    color: var(--text1);
}

.section-acts {
    display: flex;
    gap: 8px;
    align-items: center;
}

.tbl-wrap {
    background: var(--bg2);
    border: 1px solid var(--border);
    border-radius: var(--r);
    overflow: auto;
    margin-bottom: 30px;
}

.tbl {
    width: 100%;
    border-collapse: collapse;
}

.tbl thead th {
    padding: 10px 14px;
    text-align: center;
    font-size: 10.5px;
    font-weight: 700;
    letter-spacing: .08em;
    text-transform: uppercase;
    color: var(--text3);
    background: var(--bg3);
    border-bottom: 1px solid var(--border);
    white-space: nowrap;
}

.tbl tbody td {
    padding: 10px 14px;
    border-bottom: 1px solid var(--border);
    font-size: 12.5px;
    color: var(--text2);
    vertical-align: middle;
    text-align: center;
    justify-items: center;
}

.tbl tbody tr:last-child td {
    border-bottom: none;
}

.tbl tbody tr:hover td {
    background: var(--surface);
    color: var(--text1);
}

.tbl-empty {
    text-align: center;
    padding: 36px !important;
    color: var(--text3) !important;
    font-size: 12.5px !important;
}

.badge-set {
    display: inline-block;
    padding: 2px 8px;
    border-radius: 20px;
    font-size: 10.5px;
    font-weight: 700;
    background: var(--surface2);
    color: var(--text2);
}

.badge-ans {
    font-family: 'JetBrains Mono', monospace;
    font-size: 10.5px;
    color: var(--text3);
    max-width: 180px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    display: block;
}

.badge-score {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 2px 8px;
    border-radius: 20px;
    font-size: 10.5px;
    font-weight: 700;
    background: var(--green-bg);
    color: var(--green);
}

.badge-score.na {
    background: var(--surface);
    color: var(--text3);
}

/* ═══════════════════════════════════════
     LOCK SCREEN
  ═══════════════════════════════════════ */
.lock-screen {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 80px 20px;
}

.lock-icon {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: var(--surface);
    border: 1px solid var(--border2);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text3);
    margin-bottom: 20px;
}

.lock-screen h2 {
    font-size: 18px;
    font-weight: 700;
    color: var(--text1);
    margin-bottom: 8px;
}

.lock-screen p {
    font-size: 13px;
    color: var(--text2);
    margin-bottom: 24px;
}

.lock-btn-row {
    display: flex;
    gap: 12px;
    align-items: center;
    flex-wrap: wrap;
    justify-content: center;
}

.teacher-actions {
    display: flex;
    align-items: center;
    gap: 8px;
}

.teacher-badge {
    display: flex;
    align-items: center;
    gap: 7px;
    background: var(--green-bg);
    color: var(--green);
    border: 1px solid var(--green-bd);
    border-radius: var(--r-sm);
    padding: 7px 13px;
    font-size: 12.5px;
    font-weight: 600;
}

/* ═══════════════════════════════════════
     INPUTS / CONTROLS
  ═══════════════════════════════════════ */
.inp,
.sel,
.search-inp {
    background: var(--bg3);
    border: 1px solid var(--border2);
    color: var(--text1);
    border-radius: var(--r-sm);
    font-family: 'Sora', sans-serif;
    font-size: 13px;
    padding: 8px 12px;
    outline: none;
    transition: border-color .15s;
}

.inp:focus,
.sel:focus,
.search-inp:focus {
    border-color: var(--blue);
}

.inp::placeholder,
.search-inp::placeholder {
    color: var(--text3);
}

.inp {
    width: 100%;
}

.sel option {
    background: var(--bg3);
}

.search-inp {
    width: 210px;
}

.field {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.field-lbl {
    font-size: 11px;
    font-weight: 600;
    color: var(--text3);
    letter-spacing: .05em;
    text-transform: uppercase;
}

.field-group {
    display: flex;
    flex-direction: column;
    gap: 5px;
}

@keyframes idle-pulse {

    0%,
    100% {
        outline: 2px solid transparent;
    }

    50% {
        outline: 2px solid var(--blue);
    }
}

.sel-idle {
    animation: idle-pulse 1.8s ease-in-out infinite;
}

#student-exam-sel:focus {
    animation: none;
    outline: none;
}

#teacher-exam-sel-active:focus {
    animation: none;
    outline: none;
}

.req {
    color: var(--red);
}

.btn-row {
    display: flex;
    gap: 8px;
    align-items: center;
}

/* ═══════════════════════════════════════
     BUTTONS
  ═══════════════════════════════════════ */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 9px 18px;
    border-radius: var(--r-sm);
    font-family: 'Sora', sans-serif;
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    border: 1px solid transparent;
    transition: all .15s ease;
    align-self: flex-start;
}

.btn:disabled {
    opacity: .38;
    cursor: not-allowed;
    transform: none !important;
}

.btn:not(:disabled):hover {
    transform: translateY(-1px);
    filter: brightness(1.12);
}

.btn:not(:disabled):active {
    transform: translateY(0);
}

.btn.blue {
    background: var(--blue-bg);
    color: var(--blue);
    border-color: var(--blue-bd);
}

.btn.indigo {
    background: var(--indigo-bg);
    color: var(--indigo);
    border-color: var(--indigo-bd);
}

.btn.green {
    background: var(--green-bg);
    color: var(--green);
    border-color: var(--green-bd);
}

.btn.teal {
    background: var(--teal-bg);
    color: var(--teal);
    border-color: var(--teal-bd);
}

.btn.amber {
    background: var(--amber-bg);
    color: var(--amber);
    border-color: var(--amber-bd);
}

.btn.lg {
    padding: 11px 24px;
    font-size: 14px;
}

.btn-sm {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 6px 13px;
    border-radius: var(--r-sm);
    font-family: 'Sora', sans-serif;
    font-size: 12px;
    font-weight: 600;
    cursor: pointer;
    border: 1px solid transparent;
    transition: all .15s ease;
}

.btn-sm:hover {
    transform: translateY(-1px);
    filter: brightness(1.1);
}

.btn-sm.blue {
    background: var(--blue-bg);
    color: var(--blue);
    border-color: var(--blue-bd);
}

.btn-sm.crop-download-btn {
    background: var(--blue-bg);
    border-color: var(--blue-bd);
    color: var(--green);
}

.btn-sm.amber {
    background: var(--amber-bg);
    color: var(--amber);
    border-color: var(--amber-bd);
}

.btn-sm.ghost {
    background: transparent;
    border-color: var(--border2);
    color: var(--text2);
}

.btn-sm.ghost:hover {
    background: var(--surface);
    color: var(--text1);
}

.btn-sm.btn-export-soft {
    display: flex;
    align-items: center;
    gap: 5px;
    background: rgba(49, 130, 206, 0.08);
    color: #3182ce;
    border: 1px solid rgba(49, 130, 206, 0.25);
}

.btn-sm.btn-export-soft:hover {
    background: #3182ce;
    color: #fff;
    border-color: #3182ce;
}

/* Soft danger button — used in exam table delete */
.btn-sm.btn-danger-soft {
    display: flex;
    align-items: center;
    gap: 5px;
    background: rgba(229, 62, 62, 0.08);
    color: #e53e3e;
    border: 1px solid rgba(229, 62, 62, 0.25);
}

.btn-sm.btn-danger-soft:hover {
    background: #e53e3e;
    color: #fff;
    border-color: #e53e3e;
}

.btn-label {
    font-size: 12px;
    font-weight: 600;
    line-height: 1;
}

/* ═══════════════════════════════════════
     MODALS
  ═══════════════════════════════════════ */
.modal-backdrop {
    position: fixed;
    inset: 0;
    z-index: 999;
    background: rgba(0, 0, 0, .7);
    backdrop-filter: blur(6px);
    display: none;
    align-items: center;
    justify-content: center;
}

.modal-backdrop.open {
    display: flex;
    animation: fadeIn .15s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

.modal {
    background: var(--bg2);
    border: 1px solid var(--border2);
    border-radius: 14px;
    width: 100%;
    max-width: 410px;
    box-shadow: 0 30px 90px rgba(0, 0, 0, .8);
    animation: modalPop .2s cubic-bezier(.34, 1.56, .64, 1);
}

@keyframes modalPop {
    from {
        transform: scale(.94);
        opacity: 0;
    }

    to {
        transform: scale(1);
        opacity: 1;
    }
}

.modal-hdr {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 18px 22px;
    border-bottom: 1px solid var(--border);
}

.modal-hdr h3 {
    font-size: 15px;
    font-weight: 700;
    color: var(--text1);
}

.modal-x {
    background: none;
    border: none;
    color: var(--text3);
    font-size: 16px;
    cursor: pointer;
    transition: color .15s;
}

.modal-x:hover {
    color: var(--text1);
}

.modal-body {
    padding: 22px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.modal-ftr {
    display: flex;
    justify-content: flex-end;
    gap: 10px;
    padding: 14px 22px;
    border-top: 1px solid var(--border);
}

.msg {
    font-size: 12.5px;
    border-radius: var(--r-sm);
    padding: 9px 13px;
    display: none;
}

.msg.error {
    background: var(--red-bg);
    color: var(--red);
}

.msg.success {
    background: var(--green-bg);
    color: var(--green);
}

/* ═══════════════════════════════════════════════
   RESULT MODAL
═══════════════════════════════════════ */

.result-meta-box {
    background: var(--surface2, #f5f5f5);
    border-radius: 8px;
    padding: 10px 14px;
    display: flex;
    flex-direction: column;
    gap: 3px;
}

.result-meta-lbl {
    font-size: 11px;
    color: var(--text3);
    text-transform: uppercase;
    letter-spacing: .05em;
}

.result-meta-val {
    font-size: 15px;
    font-weight: 600;
    color: var(--text1);
}

/* ═══════════════════════════════════════
     TOAST
  ═══════════════════════════════════════ */
.toast {
    position: fixed;
    bottom: 22px;
    right: 22px;
    z-index: 9999;
    background: var(--surface2);
    border: 1px solid var(--border2);
    color: var(--text1);
    padding: 10px 18px;
    border-radius: var(--r-sm);
    font-size: 13px;
    font-weight: 500;
    box-shadow: 0 8px 32px rgba(0, 0, 0, .5);
    transform: translateY(16px);
    opacity: 0;
    transition: all .25s ease;
    pointer-events: none;
}

.toast.show {
    transform: translateY(0);
    opacity: 1;
}

/* ═══════════════════════════════════════
     SCROLLBAR
  ═══════════════════════════════════════ */
::-webkit-scrollbar {
    width: 5px;
    height: 5px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: var(--surface2);
    border-radius: 3px;
}

/* ═══════════════════════════════════════
     MOBILE HEADER
  ═══════════════════════════════════════ */
.mobile-header {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 300;
    height: 52px;
    background: var(--bg2);
    border-bottom: 1px solid var(--border);
    align-items: center;
    padding: 0 16px;
    gap: 12px;
}

.mobile-brand {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    font-weight: 700;
    color: var(--text1);
}

.hamburger {
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 36px;
    height: 36px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 6px;
    border-radius: var(--r-sm);
}

.hamburger span {
    display: block;
    width: 100%;
    height: 2.5px;
    border-radius: 2px;
    background: #ffffff !important;
    transition: all .2s ease;
}

.hamburger:hover span {
    display: block;
    background: #ffffff !important;
}

/* Sidebar overlay (mobile) */
.sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 150;
    background: rgba(0, 0, 0, .6);
    backdrop-filter: blur(2px);
}

/* ═══════════════════════════════════════
     RESPONSIVE — LARGE DESKTOP  (≥ 1440px)
  ═══════════════════════════════════════ */
@media (min-width: 1440px) {
    :root {
        --sidebar-w: 248px;
    }

    .main {
        padding: 36px 48px;
        max-width: 1600px;
    }

    html {
        font-size: 15px;
    }

    .grid-2 {
        gap: 18px;
        margin-bottom: 32px;
    }

    .card {
        padding: 24px;
        gap: 18px;
    }

    .page-hdr-left h1 {
        font-size: 22px;
    }

    .progress-log {
        max-height: 220px;
    }
}

/* ═══════════════════════════════════════
     RESPONSIVE — STANDARD DESKTOP  (1200px – 1439px)
  ═══════════════════════════════════════ */
@media (min-width: 1200px) and (max-width: 1439px) {
    .main {
        padding: 28px 36px;
    }

    .grid-2 {
        gap: 16px;
    }
}

/* ═══════════════════════════════════════
     RESPONSIVE — LAPTOP  (1025px – 1199px)
  ═══════════════════════════════════════ */
@media (min-width: 1025px) and (max-width: 1199px) {
    :root {
        --sidebar-w: 210px;
    }

    .main {
        padding: 24px 24px;
    }

    .grid-2 {
        gap: 12px;
    }

    .card {
        padding: 18px;
    }

    .page-hdr-left h1 {
        font-size: 18px;
    }

    .search-inp {
        width: 180px;
    }
}

/* ═══════════════════════════════════════
     RESPONSIVE — TABLET  (≤ 1024px)
  ═══════════════════════════════════════ */
@media (max-width: 1024px) {
    :root {
        --sidebar-w: 200px;
    }

    .main {
        padding: 24px 20px;
    }

    .grid-2 {
        gap: 12px;
    }

    .search-inp {
        width: 170px;
    }

    .page-hdr {
        flex-direction: column;
        gap: 12px;
    }

    .page-hdr-right {
        width: 100%;
    }

    .page-hdr-right .field-group {
        flex-direction: row;
        align-items: center;
        gap: 10px;
    }

    .page-hdr-right .sel {
        flex: 1;
    }
}

/* ═══════════════════════════════════════
     RESPONSIVE — SMALL TABLET  (769px – 900px)
  ═══════════════════════════════════════ */
@media (min-width: 769px) and (max-width: 900px) {
    :root {
        --sidebar-w: 188px;
    }

    .main {
        padding: 20px 16px;
    }

    .nav-btn {
        font-size: 11.5px;
        padding: 8px 8px;
    }

    .nav-btn-label {
        font-size: 11.5px;
    }

    .brand-name {
        font-size: 12px;
    }

    .card {
        padding: 16px;
        gap: 12px;
    }

    .card-icon {
        width: 38px;
        height: 38px;
    }

    .card-hd>div h3 {
        font-size: 13px;
    }

    .card-hd>div p {
        font-size: 11.5px;
    }

    .grid-2 {
        gap: 10px;
    }

    .section-bar {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }

    .section-acts {
        width: 100%;
    }

    .search-inp {
        width: 100%;
        flex: 1;
    }

    .progress-hdr {
        flex-direction: column;
        align-items: flex-start;
        gap: 6px;
        padding: 10px 14px;
    }

    .tbl thead th {
        font-size: 10px;
        padding: 8px 10px;
    }

    .tbl tbody td {
        font-size: 12px;
        padding: 8px 10px;
    }

    .sidebar-bottom {
        padding: 10px 12px;
    }

    .modal {
        max-width: 380px;
    }

    .modal-body {
        padding: 18px;
    }
}

/* ═══════════════════════════════════════
     RESPONSIVE — MOBILE  (≤ 768px)
  ═══════════════════════════════════════ */
@media (max-width: 768px) {

    /* Show mobile header, hide desktop sidebar by default */
    .mobile-header {
        display: flex;
    }

    .sidebar {
        transform: translateX(-100%);
        transition: transform .25s ease;
        top: 0;
        z-index: 250;
        width: 210px;
    }

    .sidebar.open {
        transform: translateX(0);
    }

    .sidebar-overlay {
        display: block;
        opacity: 0;
        pointer-events: none;
        transition: opacity .25s;
    }

    .sidebar.open~.sidebar-overlay,
    .sidebar-overlay.visible {
        opacity: 1;
        pointer-events: auto;
    }

    /* Show overlay when sidebar is open */
    .sidebar.open+.sidebar-overlay {
        display: block;
        opacity: 1;
        pointer-events: auto;
    }

    .main {
        margin-left: 0;
        padding: 72px 16px 24px;
        /* top pad for mobile header */
    }

    /* Stack to single column */
    .grid-2 {
        grid-template-columns: 1fr;
        gap: 12px;
    }

    .page-hdr {
        flex-direction: column;
        gap: 10px;
        margin-bottom: 18px;
    }

    .page-hdr-left h1 {
        font-size: 17px;
    }

    .page-hdr-right {
        width: 100%;
    }

    .page-hdr-right .sel {
        width: 100%;
    }

    .section-bar {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }

    .section-acts {
        width: 100%;
    }

    .search-inp {
        width: 100%;
    }

    /* Table — fit to screen, no horizontal scroll */
    .tbl-wrap {
        overflow-x: hidden;
    }

    .tbl {
        min-width: 0;
        width: 100%;
        table-layout: fixed;
    }

    .tbl thead th,
    .tbl tbody td {
        white-space: normal;
        word-break: break-word;
        overflow-wrap: break-word;
    }

    .tbl thead th {
        font-size: 9.5px;
        padding: 8px 8px;
        letter-spacing: .04em;
    }

    .tbl tbody td {
        font-size: 11.5px;
        padding: 8px 8px;
    }

    .badge-ans {
        max-width: 100%;
        white-space: normal;
        word-break: break-word;
    }

    /* Cards */
    .card {
        padding: 16px;
    }

    .card-hd {
        gap: 10px;
    }

    .card-hd>div h3 {
        font-size: 13px;
    }

    .card-icon {
        width: 38px;
        height: 38px;
    }

    /* Upload zone */
    .upload-zone-inner {
        padding: 14px;
    }

    /* Buttons */
    .btn {
        font-size: 12px;
        padding: 8px 14px;
    }

    .btn-row {
        flex-wrap: wrap;
    }

    .btn-row .sel {
        width: 100%;
    }

    .btn-row .btn {
        flex: 1;
        justify-content: center;
    }

    .btn-label {
        display: none;
    }

    /* Progress panel */
    .progress-log {
        max-height: 140px;
        font-size: 10.5px;
    }

    /* Modal */
    .modal {
        max-width: calc(100vw - 32px);
        margin: 0 16px;
    }

    /* Lock screen */
    .lock-screen {
        padding: 50px 16px;
    }

    .lock-screen h2 {
        font-size: 16px;
    }

    /* Teacher header */
    .teacher-badge {
        font-size: 11.5px;
        padding: 5px 10px;
    }

    /* Teacher panel header actions — stack on mobile */
    #teacher-hdr-actions>div {
        flex-wrap: wrap;
        gap: 8px;
    }

    .teacher-actions {
        display: flex;
        flex-wrap: wrap;
        align-items: center;
        gap: 8px
    }

    #teacher-exam-sel-active {
        order: 1;
        flex: 1 1 0;
        min-width: 150px;
        /* controlled minimum */
        max-width: calc(100% - 120px);
    }

    .logout-btn {
        order: 2;
        flex-shrink: 0;
    }

    .btn.green {
        order: 3;
        flex: 0 0 auto;
    }

    .teacher-badge {
        order: 4;
        flex-shrink: 0;
    }

    /* Toast */
    .toast {
        bottom: 16px;
        right: 16px;
        left: 16px;
        text-align: center;
    }

    /* Progress header stack */
    .progress-hdr {
        flex-direction: column;
        align-items: flex-start;
        gap: 6px;
        padding: 10px 14px;
    }

    /* Modal footer stack on narrow screens */
    .modal-ftr {
        flex-direction: column-reverse;
        gap: 8px;
        align-items: stretch;
    }

    .modal-ftr .btn,
    .modal-ftr .btn-sm {
        width: 100%;
        justify-content: center;
        align-self: stretch;
        text-align: center;
    }

    /* Set tabs wrap nicely */
    .set-tabs {
        gap: 5px;
    }

    .set-tab {
        font-size: 11px;
        padding: 4px 10px;
    }

    /* Lock btn row stack */
    .lock-btn-row {
        flex-direction: column;
        width: 100%;
    }

    .lock-btn-row .btn {
        width: 100%;
        justify-content: center;
        align-self: stretch;
    }

    /* Section title smaller */
    .section-ttl {
        font-size: 13px;
    }

    /* Result meta box side-by-side on mobile */
    .result-meta-box {
        padding: 8px 12px;
    }

    .result-meta-val {
        font-size: 14px;
    }

    /* Progress footer wrap */
    .progress-footer {
        flex-wrap: wrap;
        gap: 8px;
        padding: 8px 14px;
    }
}

/* ═══════════════════════════════════════
     RESPONSIVE — SMALL MOBILE  (≤ 480px)
  ═══════════════════════════════════════ */
@media (max-width: 480px) {
    .main {
        overflow-y: auto;
        padding: 68px 14px 20px;
    }

    .card {
        padding: 14px;
        gap: 11px;
    }

    .card-hd>div p {
        font-size: 11px;
    }

    .modal-body {
        padding: 16px;
        gap: 12px;
    }

    .modal-hdr {
        padding: 14px 16px;
    }

    .modal-ftr {
        padding: 12px 16px;
    }

    .progress-hdr {
        padding: 8px 12px;
    }

    .progress-log {
        padding: 10px 12px;
        font-size: 10px;
        max-height: 120px;
    }

    .btn-sm {
        font-size: 11px;
        padding: 5px 10px;
    }

    .inp,
    .sel,
    .search-inp {
        font-size: 12px;
        padding: 7px 10px;
    }

    .tbl {
        min-width: 0;
    }

    .tbl thead th {
        font-size: 9.5px;
        padding: 7px 9px;
    }

    .tbl tbody td {
        font-size: 11.5px;
        padding: 8px 9px;
    }

    .lock-icon {
        width: 64px;
        height: 64px;
    }

    .section-acts {
        flex-wrap: wrap;
    }

    .nav-btn {
        font-size: 12px;
        padding: 8px 9px;
    }

    .page-hdr-left p {
        font-size: 11px;
    }
}

/* ═══════════════════════════════════════
     RESPONSIVE — EXTRA SMALL  (≤ 400px)
  ═══════════════════════════════════════ */
@media (max-width: 400px) {
    .main {
        padding: 66px 12px 20px;
    }

    .card {
        padding: 12px;
        gap: 10px;
    }

    .page-hdr-left h1 {
        font-size: 15px;
    }

    .page-hdr-left p {
        font-size: 11px;
    }

    .btn {
        font-size: 11.5px;
        padding: 7px 12px;
    }

    .btn.lg {
        padding: 9px 18px;
        font-size: 13px;
    }

    .set-tab {
        font-size: 10.5px;
        padding: 3px 8px;
    }

    .conn-label,
    .version-tag {
        font-size: 9.5px;
    }

    .pill {
        font-size: 9px;
        padding: 1px 5px;
    }

    .modal-hdr h3 {
        font-size: 13px;
    }

    .modal-x {
        font-size: 14px;
    }

    html {
        font-size: 13px;
    }
}