/* Roboto, self-hosted (variable font, all weights) so visitors never contact Google. */
@font-face {
  font-family: 'Roboto';
  font-style: normal;
  font-weight: 100 900;
  font-display: swap;
  src: url('/fonts/roboto-latin.woff2') format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
:root {
  /* light theme: soft sky blues */
  --bg: #e8f1fa; --surface: #f8fbff; --surface-2: #eef5fc; --ink: #14273a; --muted: #4a637b;
  --line: #cbdff0; --accent: #245fa5; --accent-ink: #ffffff; --accent-soft: #d6e7f7;
  --ok: #23795a; --danger: #b3261e; --shadow: 0 1px 2px rgba(20,60,110,.07), 0 6px 20px rgba(20,60,110,.08);
  --serif: 'Roboto', system-ui, -apple-system, 'Segoe UI', sans-serif;
  --sans: 'Roboto', system-ui, -apple-system, 'Segoe UI', sans-serif;
  --radius: 12px;
}
:root[data-theme="light"] { color-scheme: light; }
/* Dark palette: applied by system preference (unless light is forced) or when dark is chosen explicitly. */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --bg: #0e1621; --surface: #152232; --surface-2: #1b2b3f; --ink: #e7eef7; --muted: #98abc0;
    --line: #26384d; --accent: #5db4f0; --accent-ink: #06121f; --accent-soft: #173350;
    --ok: #5fd0a0; --danger: #ff8f8f; --shadow: 0 1px 2px rgba(0,0,0,.45), 0 6px 20px rgba(0,0,0,.4);
  }
}
:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0e1621; --surface: #152232; --surface-2: #1b2b3f; --ink: #e7eef7; --muted: #98abc0;
  --line: #26384d; --accent: #5db4f0; --accent-ink: #06121f; --accent-soft: #173350;
  --ok: #5fd0a0; --danger: #ff8f8f; --shadow: 0 1px 2px rgba(0,0,0,.45), 0 6px 20px rgba(0,0,0,.4);
}
.theme-toggle { padding: 8px 10px; }
.login .theme-toggle { position: fixed; top: 14px; right: 14px; }
* { box-sizing: border-box; }
html, body { margin: 0; height: 100%; }
body { background: var(--bg); color: var(--ink); font: 15px/1.5 var(--sans); -webkit-font-smoothing: antialiased; }
code, pre, kbd, samp { font-family: var(--sans); }
h1, h2, h3 { font-family: var(--serif); font-weight: 600; margin: 0; letter-spacing: -.01em; }
a { color: var(--accent); }
button, input, select, textarea { font: inherit; color: inherit; }
svg.i { width: 18px; height: 18px; stroke: currentColor; fill: none; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; flex: none; }

/* buttons & fields */
.btn { display: inline-flex; align-items: center; gap: 7px; padding: 8px 14px; border-radius: 9px; border: 1px solid var(--line);
  background: var(--surface); cursor: pointer; text-decoration: none; color: var(--ink); white-space: nowrap; }
.btn:hover { border-color: var(--muted); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.btn.primary:hover { filter: brightness(1.08); }
.btn.danger { color: var(--danger); }
.btn.ghost { background: transparent; border-color: transparent; }
.btn.ghost:hover { background: var(--accent-soft); }
.btn.sm { padding: 4px 9px; font-size: 13px; }
.btn:disabled { opacity: .5; cursor: default; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
input[type=text], input[type=password], input[type=url], input[type=search], select, textarea {
  width: 100%; padding: 9px 11px; border-radius: 9px; border: 1px solid var(--line); background: var(--surface); }
textarea { resize: vertical; min-height: 90px; }
label { display: block; font-size: 13px; color: var(--muted); margin: 12px 0 4px; }

/* login */
.login { min-height: 100%; display: grid; place-items: center; padding: 16px; }
.login-card { width: 100%; max-width: 380px; background: var(--surface); border: 1px solid var(--line); border-radius: 16px;
  padding: 32px; box-shadow: var(--shadow); text-align: center; }
.mark { width: 52px; height: 52px; border-radius: 14px; background: var(--accent); color: var(--accent-ink); display: grid; place-items: center;
  font: 600 32px var(--serif); margin: 0 auto 14px; }
.login-card h1 { font-size: 26px; margin-bottom: 4px; }
.login-card p { color: var(--muted); margin: 0 0 18px; }
.login-card .btn { width: 100%; justify-content: center; margin-top: 14px; }
.err { color: var(--danger); font-size: 13px; min-height: 18px; margin-top: 8px; }
code { background: var(--surface-2); border: 1px solid var(--line); padding: 1px 6px; border-radius: 5px; font-size: 13px; }

/* shell */
.shell { display: grid; grid-template-columns: 264px 1fr; height: 100%; }
.side { background: var(--surface); border-right: 1px solid var(--line); display: flex; flex-direction: column; min-height: 0; }
.brand { display: flex; align-items: center; gap: 10px; padding: 18px 18px 10px; font: 600 18px/1.2 var(--serif); text-decoration: none; color: var(--ink); }
.badge.private { background: var(--surface-2); color: var(--muted); border: 1px solid var(--line); }
.brand .mark { width: 32px; height: 32px; font-size: 20px; margin: 0; border-radius: 9px; }
.nav { padding: 8px 10px; overflow-y: auto; flex: 1; }
.nav h4 { margin: 14px 10px 6px; font: 600 11px var(--sans); letter-spacing: .08em; text-transform: uppercase; color: var(--muted); display: flex; justify-content: space-between; align-items: center; }
.nav a.link { display: flex; align-items: center; gap: 10px; padding: 8px 10px; border-radius: 9px; color: var(--ink); text-decoration: none; }
.nav a.link:hover { background: var(--surface-2); }
.nav a.link.on { background: var(--accent-soft); color: var(--accent); font-weight: 600; }
.nav .dot { width: 10px; height: 10px; border-radius: 50%; flex: none; }
.nav .count { margin-left: auto; font-size: 12px; color: var(--muted); }
.meter { padding: 14px 18px 18px; border-top: 1px solid var(--line); font-size: 12px; color: var(--muted); }
.meter .bar { height: 6px; border-radius: 3px; background: var(--line); margin: 6px 0; overflow: hidden; }
.meter .bar i { display: block; height: 100%; background: var(--accent); }
.main { display: flex; flex-direction: column; min-width: 0; min-height: 0; }
.top { display: flex; align-items: center; gap: 10px; padding: 12px 24px; border-bottom: 1px solid var(--line); background: var(--surface); }
.top .search { position: relative; flex: 1; max-width: 520px; }
.top .search svg { position: absolute; left: 11px; top: 50%; transform: translateY(-50%); color: var(--muted); }
.top .search input { padding-left: 36px; }
.top .spacer { flex: 1; }
.menu-btn { display: none; }
.content { flex: 1; overflow-y: auto; padding: 28px 32px 80px; position: relative; }
.wrap { max-width: 1100px; margin: 0 auto; }

/* page headers */
.page-head { display: flex; align-items: flex-start; gap: 14px; flex-wrap: wrap; margin-bottom: 20px; }
.page-head h1 { font-size: 30px; }
.page-head .sub { color: var(--muted); margin-top: 2px; }
.page-head .actions { margin-left: auto; display: flex; gap: 8px; flex-wrap: wrap; }
.chips { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 18px; }
.chip { padding: 5px 12px; border-radius: 99px; border: 1px solid var(--line); background: var(--surface); cursor: pointer; font-size: 13px; }
.chip.on { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }

/* cards & lists */
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 14px; }
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow);
  text-decoration: none; color: inherit; display: block; }
a.card:hover { border-color: var(--muted); }
.course-card { padding: 16px 16px 14px; border-top: 5px solid var(--c, var(--accent)); }
.course-card h3 { font-size: 18px; margin-bottom: 4px; }
.course-card .meta, .meta { color: var(--muted); font-size: 13px; }
.thumb { aspect-ratio: 16/9; background: #000 center/cover no-repeat; position: relative; }
.thumb .play { position: absolute; inset: 0; display: grid; place-items: center; color: #fff; background: linear-gradient(transparent 50%, rgba(0,0,0,.55)); }
.thumb .pbar { position: absolute; left: 0; right: 0; bottom: 0; height: 4px; background: rgba(255,255,255,.3); }
.thumb .pbar i { display: block; height: 100%; background: #e5484d; }
.card .body { padding: 10px 12px 12px; }
.card .body .t { font-weight: 600; line-height: 1.3; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.section { margin: 30px 0 12px; display: flex; align-items: baseline; gap: 10px; }
.section h2 { font-size: 20px; }
.topic { margin: 22px 0 8px; font: 600 12px var(--sans); letter-spacing: .08em; text-transform: uppercase; color: var(--muted); }
.list { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.row { display: flex; align-items: center; gap: 12px; padding: 11px 14px; border-bottom: 1px solid var(--line); text-decoration: none; color: inherit; }
.row:last-child { border-bottom: 0; }
.row:hover { background: var(--surface-2); }
.row .ico { width: 34px; height: 34px; border-radius: 9px; background: var(--accent-soft); color: var(--accent); display: grid; place-items: center; flex: none; }
.row .main-col { flex: 1; min-width: 0; }
.row .title { font-weight: 600; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.row .prog { width: 70px; height: 4px; background: var(--line); border-radius: 2px; overflow: hidden; flex: none; }
.row .prog i { display: block; height: 100%; background: var(--accent); }
.badge { font-size: 11px; padding: 1px 7px; border-radius: 99px; background: var(--accent-soft); color: var(--accent); }
.done { color: var(--ok); }
.empty { text-align: center; padding: 56px 20px; color: var(--muted); border: 2px dashed var(--line); border-radius: var(--radius); }
.empty h3 { color: var(--ink); margin-bottom: 6px; font-size: 20px; }
.empty .btn { margin-top: 14px; }

/* item view */
.item-head { display: flex; align-items: flex-start; gap: 12px; flex-wrap: wrap; margin-bottom: 16px; }
.item-head h1 { font-size: 26px; flex: 1; min-width: 200px; }
.crumb { font-size: 13px; color: var(--muted); margin-bottom: 8px; }
.crumb a { text-decoration: none; }
.viewer { display: grid; grid-template-columns: minmax(0, 1fr) 320px; gap: 18px; align-items: start; }
.player { background: #000; border-radius: var(--radius); overflow: hidden; aspect-ratio: 16/9; }
.player iframe, .player video, .player > div { width: 100%; height: 100%; display: block; border: 0; }
audio { width: 100%; }
.speeds { display: flex; gap: 6px; margin-top: 10px; flex-wrap: wrap; align-items: center; color: var(--muted); font-size: 13px; }
.speeds button { padding: 3px 9px; border-radius: 7px; border: 1px solid var(--line); background: var(--surface); cursor: pointer; font-size: 13px; }
.speeds button.on { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.panel { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 14px; }
.panel h3 { font-size: 16px; margin-bottom: 10px; }
.note-add { display: flex; gap: 6px; margin-bottom: 10px; }
.vnotes { max-height: 460px; overflow-y: auto; display: flex; flex-direction: column; gap: 8px; }
.vnote { display: flex; gap: 8px; font-size: 14px; }
.vnote .ts { font: 600 12px var(--sans); font-variant-numeric: tabular-nums; background: var(--accent-soft); color: var(--accent); border: 0; border-radius: 6px; padding: 2px 7px; cursor: pointer; height: fit-content; flex: none; }
.vnote .x { margin-left: auto; opacity: .4; background: none; border: 0; cursor: pointer; color: inherit; }
.vnote .x:hover { opacity: 1; color: var(--danger); }
.hint { font-size: 12px; color: var(--muted); margin-top: 10px; }
.doc-frame { width: 100%; height: 78vh; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); }
.doc-img { max-width: 100%; border-radius: var(--radius); border: 1px solid var(--line); }
.file-card { text-align: center; padding: 48px 20px; }
.file-card .big { width: 64px; height: 64px; border-radius: 16px; background: var(--accent-soft); color: var(--accent); display: grid; place-items: center; margin: 0 auto 14px; }
.file-card .big svg { width: 30px; height: 30px; }
pre.text { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px; overflow: auto; white-space: pre-wrap; font: 14px/1.6 var(--sans); }
.editor-bar { display: flex; gap: 8px; align-items: center; margin-bottom: 10px; }
.editor-bar .saved { margin-left: auto; font-size: 12px; color: var(--muted); }
.note-edit { min-height: 60vh; font: 15px/1.65 var(--sans); }
.md { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px 28px; line-height: 1.7; }
.md h1, .md h2, .md h3, .md h4 { margin: 1.1em 0 .4em; }
.md h1:first-child, .md h2:first-child { margin-top: 0; }
.md p { margin: .6em 0; } .md ul, .md ol { padding-left: 1.4em; margin: .5em 0; }
.md blockquote { margin: .8em 0; padding: 2px 14px; border-left: 3px solid var(--accent); color: var(--muted); }
.md pre { background: var(--surface-2); padding: 10px 12px; border-radius: 8px; overflow: auto; }
.md hr { border: 0; border-top: 1px solid var(--line); margin: 1.2em 0; }

/* dialogs, toasts, upload queue */
dialog { border: 1px solid var(--line); border-radius: 16px; padding: 0; background: var(--surface); color: var(--ink); width: min(480px, calc(100vw - 32px)); box-shadow: 0 20px 60px rgba(0,0,0,.35); }
dialog::backdrop { background: rgba(10,8,6,.5); }
dialog form { padding: 22px 24px 20px; }
dialog h2 { font-size: 22px; margin-bottom: 4px; }
dialog .foot { display: flex; justify-content: flex-end; gap: 8px; margin-top: 20px; }
dialog .files { max-height: 160px; overflow: auto; font-size: 13px; color: var(--muted); border: 1px solid var(--line); border-radius: 8px; padding: 6px 10px; margin-top: 4px; }
#toasts { position: fixed; bottom: 18px; left: 50%; transform: translateX(-50%); display: flex; flex-direction: column; gap: 8px; z-index: 100; }
.toast { background: var(--ink); color: var(--bg); padding: 10px 16px; border-radius: 10px; box-shadow: var(--shadow); font-size: 14px; }
.toast.bad { background: var(--danger); color: #fff; }
.uploads { position: fixed; right: 18px; bottom: 18px; width: 340px; max-width: calc(100vw - 36px); background: var(--surface); border: 1px solid var(--line);
  border-radius: 14px; box-shadow: var(--shadow), 0 10px 40px rgba(0,0,0,.2); z-index: 50; overflow: hidden; }
.uploads header { display: flex; align-items: center; padding: 10px 14px; font-weight: 600; border-bottom: 1px solid var(--line); }
.uploads header button { margin-left: auto; }
.uploads .u { padding: 9px 14px; font-size: 13px; border-bottom: 1px solid var(--line); }
.uploads .u:last-child { border-bottom: 0; }
.uploads .u .n { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.uploads .bar { height: 5px; border-radius: 3px; background: var(--line); margin-top: 5px; overflow: hidden; }
.uploads .bar i { display: block; height: 100%; width: 0; background: var(--accent); transition: width .2s; }
.uploads .u.fail .bar i { background: var(--danger); }
.uploads .u.ok .bar i { background: var(--ok); }
.dropveil { position: fixed; inset: 0; z-index: 60; background: color-mix(in srgb, var(--accent) 20%, transparent); border: 4px dashed var(--accent);
  display: none; place-items: center; font: 600 28px var(--serif); color: var(--accent); pointer-events: none; }
.dropveil.on { display: grid; }

/* responsive */
@media (max-width: 860px) {
  .shell { grid-template-columns: 1fr; }
  .side { position: fixed; inset: 0 auto 0 0; width: 280px; z-index: 40; transform: translateX(-100%); transition: transform .2s; box-shadow: var(--shadow); }
  .side.open { transform: none; }
  .menu-btn { display: inline-flex; }
  .content { padding: 20px 16px 80px; }
  .top { padding: 10px 16px; }
  .viewer { grid-template-columns: 1fr; }
  .page-head h1 { font-size: 24px; }
}

/* subjects + filter chips */
.chip .n { opacity: .7; font-size: 12px; margin-left: 4px; }
.chip.sm { padding: 3px 11px; font-size: 12.5px; }
.chips.subjects .chip { font-weight: 500; }
.chips.kinds { margin-top: -6px; }
.topic .n { font-weight: 400; opacity: .7; margin-left: 4px; }
dialog.wide { width: min(780px, calc(100vw - 32px)); }
dialog input[type=file] { width: 100%; padding: 6px 0; color: var(--muted); font-size: 14px; }
dialog input[type=file]::file-selector-button { font: inherit; margin-right: 12px; padding: 8px 14px; border-radius: 9px; border: 1px solid var(--line);
  background: var(--surface); color: var(--ink); cursor: pointer; }
dialog input[type=file]::file-selector-button:hover { border-color: var(--muted); }
.subj-list { margin: 14px 0 6px; display: flex; flex-direction: column; gap: 8px; max-height: 50vh; overflow: auto; }
.subj-row { display: flex; align-items: center; gap: 4px; }
.subj-row input { flex: 1; }
.subj-row .count { min-width: 26px; text-align: center; }
.subj-add { display: flex; gap: 8px; margin-top: 12px; }

/* quiz player */
.quiz-card { background: var(--surface); border: 1px solid var(--line); border-radius: 16px; padding: 26px; box-shadow: var(--shadow); max-width: 820px; }
.quiz-meta { color: var(--muted); margin-bottom: 6px; }
.quiz-last { margin: 4px 0 8px; }
.quiz-fs { border: 0; padding: 0; margin: 18px 0 0; }
.quiz-fs legend { padding: 0; font: 600 11px var(--sans); letter-spacing: .08em; text-transform: uppercase; color: var(--muted); margin-bottom: 4px; }
.quiz-check { display: flex; align-items: flex-start; gap: 10px; margin: 6px 0; color: var(--ink); font-size: 14.5px; cursor: pointer; }
.quiz-check input { width: auto; margin-top: 4px; flex: none; accent-color: var(--accent); }
.quiz-check.inline { margin: 0; }
.quiz-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 24px; }
.quiz-top { margin-bottom: 18px; }
.quiz-bar { height: 8px; border-radius: 4px; background: var(--line); overflow: hidden; }
.quiz-bar i { display: block; height: 100%; background: var(--accent); transition: width .25s; }
.quiz-bar.big { height: 12px; margin: 6px 0 18px; }
.quiz-count { display: flex; align-items: center; gap: 14px; margin-top: 10px; font-size: 14px; }
.quiz-count .btn { margin-left: auto; }
.quiz-sec { font: 600 11px var(--sans); letter-spacing: .08em; text-transform: uppercase; color: var(--muted); margin-bottom: 8px; }
.quiz-h { font-size: 20px; margin: 0 0 8px; color: var(--accent); }
.quiz-stem p { margin: 0 0 .7em; line-height: 1.65; }
.quiz-choices { display: flex; flex-direction: column; gap: 10px; margin: 18px 0 4px; }
.qchoice { display: flex; align-items: flex-start; gap: 12px; width: 100%; text-align: left; padding: 12px 14px; border-radius: 12px;
  border: 2px solid var(--line); background: var(--surface); cursor: pointer; color: var(--ink); line-height: 1.5; }
.qchoice:hover:not(:disabled):not(.static) { border-color: var(--accent); background: var(--surface-2); }
.qchoice:disabled { cursor: default; }
.qchoice.static { cursor: default; }
.qletter { flex: none; width: 28px; height: 28px; border-radius: 50%; display: grid; place-items: center; font-weight: 600; font-size: 13px; background: var(--surface-2); color: var(--muted); border: 1px solid var(--line); }
.qtext { flex: 1; min-width: 0; }
.qchoice.picked { border-color: var(--accent); background: var(--accent-soft); }
.qchoice.picked .qletter { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.qchoice.correct { border-color: var(--ok); background: color-mix(in srgb, var(--ok) 14%, var(--surface)); }
.qchoice.correct .qletter { background: var(--ok); color: var(--bg); border-color: var(--ok); }
.qchoice.wrong { border-color: var(--danger); background: color-mix(in srgb, var(--danger) 12%, var(--surface)); }
.qchoice.wrong .qletter { background: var(--danger); color: var(--bg); border-color: var(--danger); }
.quiz-feedback { display: flex; align-items: center; gap: 8px; margin-top: 16px; padding: 11px 14px; border-radius: 10px; font-weight: 500; }
.quiz-feedback.ok { color: var(--ok); background: color-mix(in srgb, var(--ok) 14%, var(--surface)); }
.quiz-feedback.bad { color: var(--danger); background: color-mix(in srgb, var(--danger) 12%, var(--surface)); }
.quiz-expl { margin-top: 12px; padding: 14px 16px; background: var(--surface-2); border-left: 4px solid var(--accent); border-radius: 10px; }
.quiz-expl p { margin: .4em 0; line-height: 1.65; }
.quiz-nav { display: flex; align-items: center; gap: 10px; margin-top: 22px; }
.quiz-nav .spacer { flex: 1; }
.quiz-score { display: flex; align-items: baseline; gap: 14px; }
.quiz-score .big { font-size: 42px; font-weight: 500; letter-spacing: -.02em; }
.quiz-score .pct { font-size: 22px; color: var(--muted); }
.quiz-secs { margin: 4px 0 4px; }
.quiz-secs .row2 { display: flex; justify-content: space-between; gap: 12px; padding: 8px 0; border-bottom: 1px solid var(--line); }
.quiz-revhead { display: flex; align-items: center; justify-content: space-between; margin: 28px 0 8px; }
.quiz-revhead h3 { font-size: 18px; }
.quiz-rev { border: 1px solid var(--line); border-radius: 12px; margin: 8px 0; overflow: hidden; background: var(--surface); }
.quiz-rev summary { display: flex; align-items: center; gap: 10px; padding: 11px 14px; cursor: pointer; list-style: none; }
.quiz-rev summary::-webkit-details-marker { display: none; }
.quiz-rev .rmark { flex: none; display: grid; place-items: center; }
.quiz-rev.ok .rmark { color: var(--ok); }
.quiz-rev.bad .rmark { color: var(--danger); }
.quiz-rev .rl { flex: 1; min-width: 0; }
.quiz-rev-body { padding: 0 16px 16px; }
.quiz-rev-body .quiz-h { font-size: 17px; }
@media (max-width: 860px) { .quiz-card { padding: 18px; } .quiz-score .big { font-size: 34px; } }

/* nested dropdowns: subject > category > items */
.acc-tools { display: flex; gap: 6px; justify-content: flex-end; margin: -6px 0 8px; }
.acc { border: 1px solid var(--line); border-radius: 14px; background: var(--surface); margin: 0 0 12px; overflow: hidden; }
.acc > summary { display: flex; align-items: center; gap: 10px; padding: 12px 16px; cursor: pointer; list-style: none; user-select: none; }
.acc > summary::-webkit-details-marker { display: none; }
.acc > summary:hover { background: var(--surface-2); }
.acc .chev { display: grid; place-items: center; color: var(--muted); transition: transform .15s ease; }
.acc[open] > summary > .chev { transform: rotate(90deg); }
.acc > summary .lbl { flex: 1; min-width: 0; font-weight: 600; }
.acc > summary .n { color: var(--muted); font-size: 13px; font-weight: 400; white-space: nowrap; }
.acc > summary > svg.i { color: var(--accent); }
.acc.subj > summary { padding: 15px 18px; }
.acc.subj > summary .lbl { font-size: 17px; }
.acc.subj[open] > summary { border-bottom: 1px solid var(--line); }
.acc-body { padding: 12px 12px 2px; }
.acc.cat { background: var(--surface-2); border-radius: 12px; margin: 0 0 10px; }
.acc.cat > summary { padding: 10px 14px; }
.acc.cat > summary .lbl { font-size: 14.5px; }
.acc.cat[open] > summary { border-bottom: 1px solid var(--line); }
.acc.cat .list { border: 0; border-radius: 0; background: var(--surface); }
#list > .acc.cat { background: var(--surface); }   /* categories shown directly (course with no subjects) */
@media (prefers-reduced-motion: reduce) { .acc .chev { transition: none; } }