/* apl-uni demo — shared design tokens + component classes.
   Two themes via html[data-theme="dark"|"light"]. Dark (graphite-silver) is default. */

:root,
html[data-theme="dark"] {
  color-scheme: dark;
  --bg: #18191c;
  --surface: #25272b;
  --surface-hi: #2e3035;
  --surface-low: #202226;
  --ink: #f5f4ed;
  --muted: #c3c5c7;
  --faint: #a4aaa9;
  --line: #4d5355;
  --line-soft: #383e40;
  --accent: #cddbd5;
  --accent-hover: #f1f5f0;
  --danger: #ebafa4;

  --rail-start: #24262b;
  --rail-end: #181a1e;
  --rail-line: #50565b;
  --rail-ink: #f4f4f0;
  --rail-muted: #bfc5c6;
  --rail-icon: #d5ded7;
  --rail-active: #3e4949;
  --rail-accent: #e3e7e3;

  --btn-start: #e4e7e1;
  --btn-end: #b6c1bd;
  --btn-ink: #202624;
  --soft-accent: #353e3c;

  --success-fg: #c3dec9;
  --success-bg: #2b4135;
  --success-line: #64826e;
  --info-fg: #c4dbe3;
  --info-bg: #2b3c46;
  --info-line: #5f7989;
  --warn-fg: #e9d1a9;
  --warn-bg: #463f33;
  --warn-line: #8d805f;
  --danger-fg: #efbfb6;
  --danger-bg: #4a3233;
  --danger-line: #946867;
  --chart: #88b49d;

  --radius: 6px;
  --shadow: 0 18px 46px rgba(0, 0, 0, 0.35);
  --font-serif: "Tinos", "Times New Roman", "Liberation Serif", Times, serif;
  --font-body: "Arimo", Arial, "Liberation Sans", Helvetica, sans-serif;
}

html[data-theme="light"] {
  color-scheme: light;
  --bg: #f4f0e5;
  --surface: #fcfaf3;
  --surface-hi: #f1ebdc;
  --surface-low: #e8e3d5;
  --ink: #343726;
  --muted: #65614f;
  --faint: #69604f;
  --line: #d4cdb9;
  --line-soft: #e2dccb;
  --accent: #a44327;
  --accent-hover: #813317;
  --danger: #a8382e;

  --rail-start: #fcfaf3;
  --rail-end: #f1ebdc;
  --rail-line: #d4cdb9;
  --rail-ink: #343726;
  --rail-muted: #65614f;
  --rail-icon: #a44327;
  --rail-active: #eee0d4;
  --rail-accent: #a44327;

  --btn-start: #a94a2e;
  --btn-end: #8b3822;
  --btn-ink: #fff7ea;
  --soft-accent: #eee0d4;

  --success-fg: #3c5b2f;
  --success-bg: #e6ecdc;
  --success-line: #a6b892;
  --info-fg: #355b60;
  --info-bg: #e0eae6;
  --info-line: #97b7ad;
  --warn-fg: #884b24;
  --warn-bg: #f3e5ce;
  --warn-line: #c4a072;
  --danger-fg: #9e3d31;
  --danger-bg: #f6e4d8;
  --danger-line: #cd9a87;
  --chart: #587544;

  --shadow: 0 18px 46px rgba(60, 45, 20, 0.16);
}

/* ---------- reset & base ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 15px/1.5 var(--font-body);
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3, h4 {
  font-family: var(--font-serif);
  font-weight: 400;
  margin: 0 0 8px;
  color: var(--ink);
}
h1 { font-size: 30px; }
h2 { font-size: 22px; }
h3 { font-size: 18px; }
h4 { font-size: 16px; }
p { margin: 0 0 10px; color: var(--muted); }
a { color: inherit; }
button { font: inherit; color: inherit; }
ul { margin: 0; padding: 0; list-style: none; }
img { max-width: 100%; display: block; }
::selection { background: var(--accent); color: var(--btn-ink); }

.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0;
}

:focus { outline: none; }
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}
/* programmatic focus (e.g. the h1 focused after navigation for a11y) should not show a visual ring */
[tabindex="-1"]:focus { outline: none; }
[tabindex="-1"]:focus:not(:focus-visible) { outline: none; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; animation: none !important; }
}

/* ---------- app shell ---------- */
.app-shell { min-height: 100vh; }

.rail {
  position: fixed;
  inset: 0 auto 0 0;
  width: 232px;
  display: flex;
  flex-direction: column;
  background: linear-gradient(165deg, var(--rail-start), var(--rail-end) 92%);
  border-right: 1px solid var(--rail-line);
  color: var(--rail-ink);
  padding: 22px 16px;
  overflow-y: auto;
  z-index: 40;
  transition: transform 0.2s ease;
}

.rail-brand { padding: 0 6px 18px; }
.rail-wordmark {
  font-family: var(--font-serif);
  font-size: 30px;
  color: var(--rail-ink);
  margin: 0;
}
.rail-caption {
  font-size: 11px;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--rail-muted);
  margin-top: 4px;
}

.rail-nav { display: flex; flex-direction: column; gap: 2px; margin-top: 6px; flex: 1 0 auto; }
.rail-nav a {
  display: flex;
  align-items: center;
  gap: 11px;
  padding: 10px 10px;
  border-radius: var(--radius);
  color: var(--rail-ink);
  text-decoration: none;
  font-size: 14px;
  border: 1px solid transparent;
  transition: background 0.15s ease, border-color 0.15s ease;
}
.rail-nav a .nav-icon { color: var(--rail-icon); display: flex; flex-shrink: 0; }
.rail-nav a:hover { background: var(--rail-active); }
.rail-nav a.active { background: var(--rail-active); border-color: var(--rail-line); }
.rail-nav a.active .nav-icon { color: var(--rail-accent); }
.nav-label { flex: 1; }
.nav-badge {
  min-width: 20px;
  height: 20px;
  padding: 0 6px;
  border-radius: 999px;
  background: var(--rail-accent);
  color: var(--rail-end);
  font-size: 11px;
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.rail-theme {
  margin-top: 18px;
  padding-top: 16px;
  border-top: 1px solid var(--rail-line);
}
.rail-theme-label {
  font-size: 10px;
  letter-spacing: 1.1px;
  text-transform: uppercase;
  color: var(--rail-muted);
  margin-bottom: 8px;
}
.theme-switch {
  display: flex;
  background: rgba(0, 0, 0, 0.18);
  border: 1px solid var(--rail-line);
  border-radius: var(--radius);
  padding: 3px;
  gap: 3px;
}
.theme-switch button {
  flex: 1;
  border: none;
  background: transparent;
  color: var(--rail-muted);
  padding: 6px 8px;
  border-radius: 4px;
  cursor: pointer;
  font-size: 12px;
  transition: background 0.15s ease, color 0.15s ease;
}
.theme-switch button.active {
  background: var(--rail-accent);
  color: var(--rail-end);
  font-weight: 700;
}

.rail-user {
  margin-top: 18px;
  padding-top: 16px;
  border-top: 1px solid var(--rail-line);
  display: flex;
  align-items: center;
  gap: 10px;
}
.rail-user-name { font-size: 13px; font-weight: 700; color: var(--rail-ink); }
.rail-user-subtitle { font-size: 11px; color: var(--rail-muted); }

.rail-note {
  margin-top: 14px;
  font-size: 11px;
  line-height: 1.5;
  color: var(--rail-muted);
}

.rail-backdrop {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 39;
}

.content { margin-left: 232px; display: flex; flex-direction: column; min-height: 100vh; }

/* ---------- topbar ---------- */
.topbar {
  position: sticky;
  top: 0;
  z-index: 30;
  height: 72px;
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 0 28px;
  background: var(--surface-low);
  border-bottom: 1px solid var(--line);
}
.topbar-menu { display: none; }
.icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border-radius: var(--radius);
  border: 1px solid transparent;
  background: transparent;
  color: var(--ink);
  cursor: pointer;
  position: relative;
  transition: background 0.15s ease, border-color 0.15s ease;
}
.icon-btn:hover { background: var(--soft-accent); border-color: var(--line); }

.topbar-search {
  flex: 1;
  max-width: 420px;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 9px 14px;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: var(--surface-hi);
  color: var(--faint);
  cursor: pointer;
  transition: border-color 0.15s ease, background 0.15s ease;
}
.topbar-search:hover { border-color: var(--accent); background: var(--surface); }
.topbar-search span { font-size: 13px; }

.topbar-actions { display: flex; align-items: center; gap: 10px; margin-left: auto; }

.demo-pill {
  font-size: 11px;
  letter-spacing: 0.4px;
  padding: 6px 12px;
  border-radius: 999px;
  border: 1px solid var(--line);
  color: var(--accent);
  cursor: default;
}

.user-menu { position: relative; }
.avatar-btn {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 5px 8px;
  border-radius: var(--radius);
  border: 1px solid transparent;
  background: transparent;
  cursor: pointer;
  transition: background 0.15s ease, border-color 0.15s ease;
}
.avatar-btn:hover { background: var(--soft-accent); border-color: var(--line); }
.avatar-btn-meta { display: flex; flex-direction: column; align-items: flex-start; line-height: 1.3; }
.avatar-btn .user-name { font-size: 13px; font-weight: 700; }
.avatar-btn .user-sub { font-size: 11px; color: var(--muted); }
.avatar-btn .chev { color: var(--muted); display: flex; }

.avatar {
  width: 34px;
  height: 34px;
  border-radius: 999px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--btn-start), var(--btn-end));
  color: var(--btn-ink);
  font-size: 12px;
  font-weight: 700;
  flex-shrink: 0;
}

.dropdown {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  min-width: 200px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 6px;
  z-index: 35;
}
.dropdown button {
  display: block;
  width: 100%;
  text-align: left;
  padding: 9px 10px;
  border-radius: 4px;
  border: none;
  background: transparent;
  cursor: pointer;
  font-size: 13px;
  color: var(--ink);
}
.dropdown button:hover { background: var(--soft-accent); }

/* ---------- main & footer ---------- */
.main {
  flex: 1;
  width: 100%;
  max-width: 1400px;
  margin: 0 auto;
  padding: 28px;
}
.footer {
  padding: 18px 28px 28px;
  font-size: 12px;
  color: var(--faint);
  text-align: center;
}

/* ---------- page heading ---------- */
.page-heading {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 22px;
}
.page-heading .eyebrow {
  font-size: 11px;
  letter-spacing: 1.2px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 6px;
}
.page-heading h1 { margin-bottom: 6px; }
.page-heading .desc { color: var(--muted); max-width: 640px; margin: 0; }
.page-heading .actions { display: flex; gap: 10px; flex-wrap: wrap; }

/* ---------- panel ---------- */
.panel {
  background: linear-gradient(160deg, var(--surface-hi), var(--surface));
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
  margin-bottom: 18px;
}
.panel-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
}
.panel-title-wrap { display: flex; align-items: center; gap: 10px; }
.panel-icon { color: var(--accent); display: flex; flex-shrink: 0; }
.panel-title { margin: 0; font-size: 18px; }
.panel-sub { font-size: 12px; color: var(--muted); margin-top: 2px; }
.panel-actions { display: flex; gap: 8px; flex-wrap: wrap; flex-shrink: 0; }
.panel-body { color: var(--ink); }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 16px;
  font-size: 13px;
  font-weight: 700;
  border-radius: var(--radius);
  border: 1px solid var(--btn-end);
  background: linear-gradient(130deg, var(--btn-start), var(--btn-end));
  color: var(--btn-ink);
  box-shadow: inset 0 1px rgba(255, 255, 255, 0.12);
  cursor: pointer;
  transition: transform 0.12s ease, box-shadow 0.12s ease, background 0.12s ease, border-color 0.12s ease;
}
.btn:hover { box-shadow: var(--shadow); transform: translateY(-1px); }
.btn:active { transform: translateY(0); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; transform: none; box-shadow: none; }

.btn-secondary {
  background: transparent;
  border-color: var(--accent);
  color: var(--accent);
  box-shadow: none;
}
.btn-secondary:hover { background: var(--soft-accent); border-color: var(--accent-hover); }

.btn-ghost {
  background: transparent;
  border-color: transparent;
  color: var(--accent);
  box-shadow: none;
}
.btn-ghost:hover { background: var(--soft-accent); border-color: var(--line); }

.btn-danger {
  background: var(--danger-bg);
  color: var(--danger-fg);
  border-color: var(--danger-line);
  box-shadow: none;
}
.btn-danger:hover { background: var(--danger-bg); border-color: var(--danger); }

.btn-sm, .btn.small { padding: 6px 12px; font-size: 12px; }

/* ---------- badges ---------- */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 3px 10px;
  border-radius: 999px;
  font-size: 11px;
  font-weight: 700;
  border: 1px solid var(--line);
  color: var(--muted);
  background: var(--surface-low);
  white-space: nowrap;
}
.badge-success { color: var(--success-fg); background: var(--success-bg); border-color: var(--success-line); }
.badge-info { color: var(--info-fg); background: var(--info-bg); border-color: var(--info-line); }
.badge-warn { color: var(--warn-fg); background: var(--warn-bg); border-color: var(--warn-line); }
.badge-danger { color: var(--danger-fg); background: var(--danger-bg); border-color: var(--danger-line); }
.badge-accent { color: var(--accent); background: var(--soft-accent); border-color: var(--line); }
/* aliases: items.js (and other call sites) use .badge.success|info|warn|danger|neutral instead of .badge-*  */
.badge.success { color: var(--success-fg); background: var(--success-bg); border-color: var(--success-line); }
.badge.info { color: var(--info-fg); background: var(--info-bg); border-color: var(--info-line); }
.badge.warn { color: var(--warn-fg); background: var(--warn-bg); border-color: var(--warn-line); }
.badge.danger { color: var(--danger-fg); background: var(--danger-bg); border-color: var(--danger-line); }
.badge.neutral { color: var(--muted); background: var(--surface-low); border-color: var(--line); }

/* ---------- metrics ---------- */
.metrics {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 14px;
  margin-bottom: 18px;
}
.metric {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px;
}
.metric-label {
  font-size: 11px;
  letter-spacing: 0.6px;
  text-transform: uppercase;
  color: var(--faint);
  margin-bottom: 8px;
}
.metric-value { font-family: var(--font-serif); font-size: 28px; color: var(--ink); }
.metric-hint { font-size: 12px; color: var(--muted); margin-top: 6px; }

/* ---------- empty state ---------- */
.empty {
  text-align: center;
  padding: 44px 20px;
  color: var(--muted);
}
.empty .empty-icon { color: var(--faint); display: flex; justify-content: center; margin-bottom: 14px; }
.empty h3 { margin-bottom: 6px; }
.empty p { margin: 0 auto; max-width: 380px; }

/* ---------- tabs ---------- */
.tabs {
  display: flex;
  gap: 4px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 18px;
  flex-wrap: wrap;
}
.tabs button {
  border: none;
  background: transparent;
  color: var(--muted);
  padding: 10px 14px;
  border-bottom: 2px solid transparent;
  cursor: pointer;
  font-size: 13px;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: color 0.15s ease, border-color 0.15s ease;
}
.tabs button:hover { color: var(--ink); }
.tabs button.active { color: var(--accent); border-color: var(--accent); }
.tabs button .tab-count {
  font-size: 11px;
  padding: 1px 7px;
  border-radius: 999px;
  background: var(--surface-low);
  color: var(--muted);
}
.tabs button.active .tab-count { background: var(--soft-accent); color: var(--accent); }

/* ---------- progress ---------- */
.progress { display: flex; flex-direction: column; gap: 6px; margin-bottom: 10px; }
.progress:last-child { margin-bottom: 0; }
.progress-track {
  height: 8px;
  border-radius: 999px;
  background: var(--line-soft);
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  border-radius: 999px;
  background: var(--chart);
  transition: width 0.25s ease;
}
.progress-label {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px;
  font-size: 12px;
  color: var(--muted);
}
.progress-label-pct { flex-shrink: 0; color: var(--ink); font-weight: 700; }

/* ---------- timetable ---------- */
.timetable { width: 100%; }
.timetable-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 10px;
}
.timetable-day {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 10px;
  min-height: 60px;
}
.timetable-day-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 12px;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 8px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--line-soft);
}
.timetable-add {
  width: 22px;
  height: 22px;
  border-radius: 5px;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--accent);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
}
.timetable-add:hover { background: var(--soft-accent); }
.timetable-entry {
  background: var(--surface-hi);
  border: 1px solid var(--line-soft);
  border-radius: 5px;
  padding: 7px 9px;
  margin-bottom: 7px;
  font-size: 12px;
}
.timetable-entry:last-child { margin-bottom: 0; }
.timetable-entry .tt-time { font-weight: 700; color: var(--accent); }
.timetable-entry .tt-subject { color: var(--ink); margin: 2px 0; }
.timetable-entry .tt-meta { color: var(--muted); font-size: 11px; }
.timetable-entry .tt-actions { display: flex; gap: 5px; margin-top: 5px; }
.timetable-entry .tt-actions button {
  border: none;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  padding: 2px;
  display: inline-flex;
}
.timetable-entry .tt-actions button:hover { color: var(--accent); }

@media (max-width: 800px) {
  .timetable-grid { grid-template-columns: 1fr; }
}

/* ---------- forms ---------- */
.field { display: block; margin-bottom: 14px; }
.field label, .field-label {
  display: block;
  font-size: 12px;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 6px;
}
.field-hint { font-size: 11px; color: var(--muted); margin-top: 5px; }
.form-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 14px 16px; }

.input, textarea, select {
  width: 100%;
  padding: 9px 12px;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: var(--surface-low);
  color: var(--ink);
  font: inherit;
  transition: border-color 0.15s ease;
}
.input:hover, textarea:hover, select:hover { border-color: var(--accent); }
.input::placeholder, textarea::placeholder { color: var(--faint); }
.input:disabled, textarea:disabled, select:disabled { opacity: 0.85; cursor: default; }
textarea { resize: vertical; min-height: 80px; }
input[type="checkbox"], input[type="radio"] { accent-color: var(--accent); width: auto; }

/* ---------- table ---------- */
.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius); }
.table { width: 100%; border-collapse: collapse; font-size: 13px; }
.table th, .table td {
  text-align: left;
  padding: 11px 14px;
  border-bottom: 1px solid var(--line-soft);
  white-space: nowrap;
}
.table th {
  font-size: 11px;
  letter-spacing: 0.4px;
  text-transform: uppercase;
  color: var(--faint);
  background: var(--surface-low);
}
.table tbody tr:last-child td { border-bottom: none; }
.table tbody tr:hover td { background: var(--surface-hi); }

/* ---------- modal ---------- */
dialog.modal {
  padding: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--ink);
  width: min(560px, 92vw);
  box-shadow: var(--shadow);
}
dialog.modal.wide { width: min(820px, 94vw); }
dialog.modal::backdrop { background: rgba(0, 0, 0, 0.55); }
.modal-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 20px;
  border-bottom: 1px solid var(--line);
}
.modal-head h2 { margin: 0; font-size: 19px; }
.modal-close {
  border: none;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  display: inline-flex;
  padding: 4px;
  border-radius: 4px;
}
.modal-close:hover { background: var(--soft-accent); color: var(--ink); }
.modal-body { padding: 20px; max-height: 64vh; overflow-y: auto; }
.modal-foot {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  padding: 16px 20px;
  border-top: 1px solid var(--line);
  flex-wrap: wrap;
}

/* ---------- toasts ---------- */
.toast-stack {
  position: fixed;
  right: 20px;
  bottom: 20px;
  z-index: 60;
  display: flex;
  flex-direction: column;
  gap: 10px;
  pointer-events: none;
}
.toast {
  pointer-events: auto;
  min-width: 240px;
  max-width: 360px;
  padding: 12px 16px;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: var(--surface-hi);
  color: var(--ink);
  box-shadow: var(--shadow);
  font-size: 13px;
  animation: toast-in 0.2s ease;
}
.toast-success { background: var(--success-bg); color: var(--success-fg); border-color: var(--success-line); }
.toast-error { background: var(--danger-bg); color: var(--danger-fg); border-color: var(--danger-line); }
@keyframes toast-in {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ---------- exercise items (shared/items.js) ---------- */
.item {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px;
  margin-bottom: 14px;
}
.item:last-child { margin-bottom: 0; }
.item-prompt {
  font-weight: 700;
  color: var(--ink);
  line-height: 1.5;
  margin-bottom: 12px;
}

/* options (multiple_choice, true_false) rendered as selectable cards */
.item-options { display: flex; flex-direction: column; gap: 8px; }
.option {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: var(--surface-low);
  cursor: pointer;
  transition: border-color 0.15s ease, background 0.15s ease;
}
.option:hover { border-color: var(--accent); background: var(--surface-hi); }
.option input[type="radio"], .option input[type="checkbox"] { flex-shrink: 0; margin: 0; }
.option span { color: var(--ink); }
.option:has(input:disabled) { cursor: default; }
.option:has(input:disabled):hover { border-color: var(--line); background: var(--surface-low); }
.option:has(input:checked) { border-color: var(--accent); background: var(--soft-accent); }
.option.correct {
  border-color: var(--success-line);
  background: var(--success-bg);
}
.option.correct span { color: var(--success-fg); }
.option.wrong {
  border-color: var(--danger-line);
  background: var(--danger-bg);
}
.option.wrong span { color: var(--danger-fg); }

/* short_answer: bare <input> is a direct child of .item (not nested in a wrapper) */
.item > input[type="text"] {
  width: 100%;
  padding: 9px 12px;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: var(--surface-low);
  color: var(--ink);
  font: inherit;
  transition: border-color 0.15s ease;
}
.item > input[type="text"]:hover { border-color: var(--accent); }
.item > input[type="text"]:disabled { opacity: 0.85; cursor: default; }
.item > input[type="text"]::placeholder { color: var(--faint); }

/* cloze: inline gap inputs sized to their content */
.cloze-text { line-height: 2.2; color: var(--ink); }
.cloze-gap {
  display: inline-block;
  width: 6em;
  field-sizing: content;
  min-width: 48px;
  max-width: 260px;
  padding: 4px 8px;
  margin: 0 2px;
  border-radius: 4px;
  border: 1px solid var(--line);
  background: var(--surface-low);
  color: var(--ink);
  font: inherit;
  text-align: center;
  transition: border-color 0.15s ease;
}
.cloze-gap:hover { border-color: var(--accent); }
.cloze-gap:disabled { opacity: 0.85; cursor: default; }

/* matching: two-column rows (label + select) */
.matching-rows { display: flex; flex-direction: column; gap: 8px; }
.match-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: var(--surface-low);
}
.match-row span { color: var(--ink); font-weight: 700; }
.match-row select { margin: 0; }

/* ordering: rows with compact up/down reorder buttons */
.order-list { display: flex; flex-direction: column; gap: 8px; }
.order-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 10px 12px;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: var(--surface-low);
}
.order-row span:first-child { color: var(--ink); }
.order-actions { display: flex; gap: 6px; flex-shrink: 0; }
.order-up, .order-down { width: 32px; height: 32px; padding: 0; gap: 0; }

/* calculation: narrow value input + unit label */
.calc-row { display: flex; align-items: center; gap: 10px; }
.calc-row input[type="text"] {
  width: 8em;
  field-sizing: content;
  min-width: 110px;
  max-width: 220px;
  padding: 9px 12px;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: var(--surface-low);
  color: var(--ink);
  font: inherit;
  transition: border-color 0.15s ease;
}
.calc-row input[type="text"]:hover { border-color: var(--accent); }
.calc-row input[type="text"]:disabled { opacity: 0.85; cursor: default; }
.unit { color: var(--muted); font-size: 13px; }

/* solution / rubric (shown when a solution or model answer is revealed) */
.solution {
  margin-top: 14px;
  padding: 12px 14px;
  border-left: 3px solid var(--accent);
  background: var(--surface-low);
  border-radius: 0 var(--radius) var(--radius) 0;
  font-size: 13px;
  color: var(--muted);
}
.solution strong { color: var(--ink); }
.solution > div + div { margin-top: 6px; }
.solution ol { margin: 8px 0 0; padding-left: 20px; list-style: decimal; }
.solution ol li { margin-bottom: 4px; }
.rubric { margin: 8px 0 0; padding-left: 20px; list-style: disc; color: var(--muted); font-size: 13px; }
.rubric li { margin-bottom: 4px; }

/* ---------- responsive: rail becomes off-canvas drawer ---------- */
@media (max-width: 899px) {
  .rail {
    transform: translateX(-100%);
  }
  .rail.open { transform: translateX(0); box-shadow: var(--shadow); }
  .rail-backdrop.open { display: block; }
  .content { margin-left: 0; }
  .topbar-menu { display: inline-flex; }
  .topbar-search span { display: none; }
  .topbar-search { max-width: none; flex: 0 0 auto; padding: 9px; }
  .avatar-btn .user-name, .avatar-btn .user-sub { display: none; }
  .main { padding: 18px; }
  .topbar { padding: 0 16px; gap: 10px; }
}

@media (max-width: 480px) {
  .page-heading { align-items: flex-start; }
  .metrics { grid-template-columns: 1fr 1fr; }
  .demo-pill { display: none; }

  .match-row { grid-template-columns: 1fr; gap: 6px; }
  .order-row { flex-wrap: wrap; }
  .calc-row { flex-wrap: wrap; }
}