:root {
  color-scheme: light dark;
  --ink: #252525; --muted: #656565; --primary: #245aa7; --selection: #cfe1ff;
  --canvas: #f3f3f3; --surface: #ffffff; --soft: #ededed; --line: #d8d8d8;
  --accent: #245aa7; --accent-soft: #eeeeee; --button: #245aa7; --on-button: #fff;
  --focus: #245aa7; --positive: #174c87; --positive-bg: #f0f0f0; --positive-line: #b2cef2;
  --negative: #923d2c; --negative-bg: #f0f0f0; --negative-line: #bdbdbd;
  --notice: #745735; --notice-bg: #f0f0f0; --notice-line: #d0d0d0;
  --radius: 16px; --control-line: #858585; --sticky-height: 0px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --ink: #e6edf8; --muted: #aab9cf; --primary: #94bbff; --selection: #2c4771;
    --canvas: #111927; --surface: #1a2434; --soft: #243147; --line: #3a4b65;
    --accent: #94bbff; --accent-soft: #263d60; --button: #94bbff; --on-button: #10213c;
    --focus: #accbff; --positive: #bcdbff; --positive-bg: #1d3550; --positive-line: #456b94;
    --negative: #ffd0bc; --negative-bg: #432b24; --negative-line: #925d49;
    --notice: #e6cea8; --notice-bg: #3a3223; --notice-line: #6b5d40; --control-line: #778aa6;
  }
}
*, *::before, *::after { box-sizing: border-box; }
body, h1, h2, h3, p, figure { margin: 0; }
html { scroll-padding-top: calc(var(--sticky-height) + 16px); }
body { background: var(--canvas); color: var(--ink); font: 15px/1.55 'Segoe UI Variable', 'Segoe UI', system-ui, sans-serif; -webkit-font-smoothing: antialiased; }
button, input, select { font: inherit; color: inherit; }
button { cursor: pointer; border: 0; background: none; }
button:disabled { cursor: default; opacity: .45; }
a { color: inherit; text-underline-offset: 3px; }
img { display: block; max-width: 100%; }
[hidden] { display: none !important; }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 3px; }
::selection { background: var(--selection); color: var(--ink); }
h1, h2, h3 { font-weight: 620; }
h1 { font-size: clamp(27px, 3.1vw, 42px); line-height: 1.2; letter-spacing: -1.3px; max-width: 1000px; text-wrap: balance; }
h2 { font-size: 24px; line-height: 1.3; letter-spacing: -.5px; }
h3 { font-size: 14px; }
select { background: var(--surface); border: 1px solid var(--line); border-radius: 8px; padding: 10px 28px 10px 11px; min-width: 0; min-height: 44px; width: 100%; cursor: pointer; }
input[type=checkbox], input[type=radio] { accent-color: var(--button); }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
.skip-link { position: fixed; top: -80px; left: 16px; z-index: 20; background: var(--button); color: var(--on-button); padding: 12px 18px; border-radius: 10px; }
.skip-link:focus { top: 12px; }
.site-header { display: flex; align-items: center; justify-content: space-between; gap: 25px; min-height: 74px; border-bottom: 1px solid var(--line); padding: 0 max(24px, calc((100vw - 1400px)/2)); background: var(--surface); }
.brand { min-height: 64px; user-select: none; -webkit-user-select: none; display: flex; gap: 11px; align-items: center; text-decoration: none; font-size: 23px; line-height: 1; font-weight: 750; letter-spacing: -1px; white-space: nowrap; }
.brand-light { font-weight: 450; }
.brand-mark { display: grid; grid-template-columns: 9px 9px; gap: 3px; width: 26px; }
.brand-mark i { display: block; height: 9px; background: var(--primary); border-radius: 2px; }
.brand-mark i:last-child { transform: rotate(15deg); opacity: .65; }
.site-header nav { display: flex; align-items: stretch; align-self: stretch; gap: 26px; }
.site-header nav > * { display: flex; align-items: center; text-decoration: none; font-size: 13px; color: var(--muted); position: relative; padding: 0; }
.site-header nav .nav-active { color: var(--primary); font-weight: 650; }
.nav-active::after { position: absolute; content: ''; height: 3px; background: var(--primary); bottom: 0; left: 0; right: 0; }
.page-shell { max-width: 1400px; padding: 0 24px; margin: auto; }
.intro { padding: 35px 0 33px; }
.workspace { display: grid; grid-template-columns: 286px minmax(0, 1fr); gap: 32px; align-items: start; }
.filters { border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); overflow: auto; position: sticky; top: 16px; max-height: calc(100dvh - 32px); scrollbar-width: thin; }
.filter-top { padding: 18px 20px; display: flex; justify-content: space-between; align-items: center; border-bottom: 1px solid var(--line); }
.filter-top h2 { font-size: 15px; letter-spacing: -.2px; }
.filter-top > span { font-size: 23px; color: var(--muted); line-height: 1; }
.filter-section { padding: 18px; border-bottom: 1px solid var(--line); }
.filter-section:last-of-type { border-bottom: 0; }
.filter-section h3 { display: flex; gap: 9px; align-items: center; margin-bottom: 13px; }
.step { font-size: 11px; color: var(--muted); font-weight: 500; }
.subject-switch { display: grid; grid-template-columns: 1fr 1fr; background: var(--soft); padding: 4px; border-radius: 9px; gap: 4px; }
.subject-switch button { border-radius: 6px; min-height: 44px; padding: 9px 7px; font-size: 14px; font-weight: 600; display: flex; align-items: center; justify-content: center; gap: 7px; color: var(--muted); }
.subject-switch button[aria-pressed=true] { background: var(--button); color: var(--on-button); }
.subject-switch button > span { font-size: 19px; line-height: 1; }
.section-heading { display: flex; justify-content: space-between; gap: 8px; align-items: baseline; }
.small-link { font-size: 12px; color: var(--accent); padding: 4px 0; }
.small-link:hover, .text-button:hover { text-decoration: underline; text-underline-offset: 3px; }
.topic-search { display: flex; align-items: center; gap: 8px; background: var(--surface); border: 1px solid var(--line); border-radius: 8px; padding: 0 11px; margin-bottom: 9px; }
.topic-search:focus-within { outline: 2px solid var(--focus); outline-offset: 1px; }
.topic-search svg { width: 17px; height: 17px; stroke: var(--muted); stroke-width: 1.6; fill: none; flex-shrink: 0; }
.topic-search input { width: 100%; min-width: 0; min-height: 44px; background: none; border: 0; outline: 0; padding: 10px 0; font-size: 13px; }
.topic-search input::placeholder { color: var(--muted); }
.topic-list { max-height: 300px; overflow: auto; scrollbar-width: thin; scrollbar-color: var(--line) transparent; padding-right: 3px; }
.topic-row { display: flex; align-items: center; gap: 10px; min-height: 44px; padding: 9px 4px; border-radius: 5px; cursor: pointer; font-size: 13px; line-height: 1.4; }
.topic-row:hover { background: var(--soft); }
.topic-row:has(input:checked) { color: var(--primary); font-weight: 600; }
.topic-row input { width: 17px; height: 17px; margin: 0; flex-shrink: 0; }
.topic-row > span:first-of-type { flex: 1; min-width: 0; }
.topic-count { font-size: 11px; color: var(--muted); font-weight: 400; }
.all-topics { margin-bottom: 5px; border-radius: 0; border-bottom: 1px solid var(--line); }
.filter-hint { color: var(--muted); font-size: 11px; line-height: 1.6; margin-top: 12px; }
.filter-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 12px; }
.field { display: grid; gap: 6px; color: var(--muted); font-size: 12px; min-width: 0; }
.field select { width: 100%; color: var(--ink); font-size: 13px; }
.progress-field { margin-top: 12px; }
.reset-filters { margin-top: 12px; min-height: 36px; }
.practice { min-width: 0; padding-top: 3px; }
.results-toolbar { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: 14px; margin-bottom: 14px; }
.eyebrow { color: var(--muted); font-size: 10px; line-height: 1.6; font-weight: 700; letter-spacing: 1.6px; margin-bottom: 5px; }
.results-toolbar h2 { display: flex; align-items: center; gap: 10px; }
.count-badge { color: var(--accent); font-size: 12px; letter-spacing: 0; font-weight: 600; padding: 4px 9px; background: var(--accent-soft); border-radius: 7px; }
.ordering { display: flex; align-items: center; gap: 9px; min-width: 0; }
.ordering .button { padding: 10px 12px; }
.sort-field { min-width: 130px; font-size: 12px; }
.sort-field select { font-size: 12px; }
.active-filters { display: flex; flex-wrap: wrap; gap: 7px; }
.active-filters:not(:empty) { padding-bottom: 10px; }
.filter-chip { display: flex; gap: 9px; align-items: center; border: 1px solid var(--line); border-radius: 20px; padding: 6px 11px; font-size: 12px; color: var(--accent); background: var(--accent-soft); text-align: left; }
.filter-chip span { font-size: 16px; }
.feed-status { color: var(--muted); font-size: 12px; border-top: 1px solid var(--line); padding: 13px 0; }
.question-card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; margin-bottom: 24px; scroll-margin-top: 20px; }
.question-header { padding: 22px 26px 19px; border-bottom: 1px solid var(--line); }
.question-header-top { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 12px; }
.question-kind { color: var(--muted); font-size: 11px; font-weight: 650; letter-spacing: 1px; text-transform: uppercase; }
.source-link { font-size: 12px; color: var(--accent); text-decoration: none; white-space: nowrap; }
.source-link:hover { text-decoration: underline; }
.question-title-row { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: 12px; }
.question-title { font-size: 23px; letter-spacing: -.5px; }
.calculator-tag { display: inline-flex; align-items: center; font-size: 11px; font-weight: 600; border: 1px solid var(--line); padding: 5px 9px; border-radius: 5px; color: var(--accent); background: var(--accent-soft); }
.calculator-tag.prohibited { color: var(--notice); background: var(--notice-bg); border-color: var(--notice-line); }
.question-topics { display: flex; flex-wrap: wrap; gap: 7px; margin-top: 12px; }
.topic-tag { color: var(--muted); border-radius: 4px; font-size: 11px; background: var(--soft); padding: 3px 7px; }
.topic-tag.matched { background: var(--accent-soft); color: var(--accent); }
.question-body { padding: 24px; }
.question-segment + .question-segment { margin-top: 24px; padding-top: 18px; border-top: 1px dashed var(--line); }
.question-segment figcaption { color: var(--muted); font-size: 12px; margin-bottom: 10px; }
/* Scans keep their original bytes and colours in either interface theme. */
.scan-link { display: block; background: #fff; color-scheme: only light; cursor: zoom-in; border-radius: 3px; overflow: hidden; }
.scan { width: 100%; height: auto; background: #fff; filter: none; mix-blend-mode: normal; opacity: 1; color-scheme: only light; }
.focus-note { border-left: 3px solid var(--line); background: var(--soft); padding: 11px 14px; font-size: 12px; margin-bottom: 20px; }
.focus-note strong { display: block; font-size: 12px; margin-bottom: 4px; }
.focus-note p + p { margin-top: 4px; }
.focus-note .context-note { color: var(--muted); font-size: 11px; margin-top: 7px; }
.button { display: inline-flex; justify-content: center; align-items: center; gap: 12px; padding: 11px 17px; min-height: 44px; border-radius: 8px; border: 1px solid transparent; font-size: 13px; font-weight: 600; text-decoration: none; }
.button-primary { background: var(--button); color: var(--on-button); }
.button-primary:hover:not(:disabled) { opacity: .86; }
.button-outline { border-color: var(--line); background: var(--surface); }
.button-outline:hover:not(:disabled) { background: var(--soft); }
.button-done { background: var(--accent-soft); color: var(--accent); border-color: var(--line); }
.answer-area { background: var(--soft); border-top: 1px solid var(--line); padding: 22px 26px; }
.answer-heading { margin-bottom: 16px; }
.answer-heading h3 { font-size: 16px; }
.answer-heading p { font-size: 13px; color: var(--muted); margin-top: 3px; }
.answer-form fieldset { border: 0; padding: 0; margin: 0; }
.options { display: grid; grid-template-columns: repeat(5, minmax(44px, 53px)); gap: 9px; }
.option { position: relative; display: flex; align-items: center; justify-content: center; border: 1px solid var(--line); border-radius: 8px; height: 47px; font-size: 16px; font-weight: 650; background: var(--surface); cursor: pointer; }
.option input { position: absolute; opacity: 0; width: 1px; height: 1px; }
.option:has(input:focus-visible) { outline: 3px solid var(--focus); outline-offset: 3px; }
.option:has(input:checked) { background: var(--button); color: var(--on-button); border-color: var(--button); }
.option:hover:has(input:not(:disabled)) { border-color: var(--primary); }
.option:has(input:disabled) { cursor: default; }
.option.answer-correct { border: 2px solid var(--positive-line); background: var(--positive-bg); color: var(--positive); }
.option.answer-wrong { border-color: var(--negative-line); background: var(--negative-bg); color: var(--negative); }
.answer-actions { display: flex; align-items: center; gap: 14px; margin-top: 17px; }
.answer-feedback { border: 1px solid var(--positive-line); background: var(--positive-bg); border-radius: 8px; padding: 13px 16px; color: var(--positive); margin-top: 18px; display: flex; gap: 10px; align-items: flex-start; font-size: 13px; }
.answer-feedback strong { display: block; }
.answer-feedback.incorrect { background: var(--negative-bg); border-color: var(--negative-line); color: var(--negative); }
.feedback-icon { font-size: 19px; line-height: 1.2; }
.marking-details { border-top: 1px solid var(--line); background: var(--soft); }
.marking-details > summary { display: flex; align-items: center; gap: 11px; cursor: pointer; padding: 20px 26px; list-style: none; font-size: 13px; font-weight: 600; }
.marking-details > summary::-webkit-details-marker { display: none; }
.marking-details > summary::after { content: ''; mask: url('./icons/phosphor/caret-down.svg') center/contain no-repeat; background: currentColor; width: 18px; height: 18px; margin-left: auto; font-size: 21px; color: var(--accent); font-weight: 400; }
.marking-details[open] > summary::after { transform: rotate(180deg); }
.marking-details > summary:hover { background: var(--accent-soft); }
.marking-icon { font-size: 19px; color: var(--accent); }
.marking-content { padding: 0 20px 22px; }
.marking-content .question-segment { padding: 12px; border: 1px solid var(--line); border-radius: 8px; background: var(--surface); }
.marking-content .question-segment + .question-segment { margin-top: 16px; }
.marking-source { display: block; text-align: right; margin-top: 12px; white-space: normal; }
.multiple-choice-key { margin: 17px 0 0; border: 1px solid var(--line); border-radius: 8px; }
.multiple-choice-key > summary { padding: 12px 15px; font-size: 12px; }
.multiple-choice-key .marking-content { padding: 0 14px 14px; }
.written-footer { display: flex; align-items: center; justify-content: space-between; gap: 15px; padding: 16px 26px; border-top: 1px solid var(--line); background: var(--surface); }
.written-footer p { color: var(--muted); font-size: 12px; }
.written-footer .button { flex-shrink: 0; font-size: 12px; }
.feed-tail { text-align: center; padding: 4px 0 20px; }
.feed-tail p { font-size: 12px; color: var(--muted); margin-top: 12px; }
.load-earlier { width: 100%; margin-bottom: 18px; }
.loading-state, .empty-state { text-align: center; background: var(--surface); padding: 50px 22px; border: 1px solid var(--line); border-radius: var(--radius); }
.loading-state h2, .empty-state h2 { font-size: 22px; }
.empty-state p { color: var(--muted); margin: 10px auto 22px; max-width: 360px; font-size: 13px; }
.loading-mark { display: inline-block; width: 23px; height: 23px; border: 2px solid var(--line); border-top-color: var(--primary); border-radius: 50%; }
.site-footer { border-top: 1px solid var(--line); padding: 22px 0 28px; margin-top: 20px; font-size: 11px; color: var(--muted); }
.info-dialog { position: fixed; border: 1px solid var(--line); border-radius: 18px; max-width: 560px; max-height: calc(100dvh - 32px); width: calc(100% - 32px); padding: 34px; color: var(--ink); background: var(--surface); overflow: auto; }
.info-dialog::backdrop { background: #10251d99; }
.info-dialog h2 { font-size: 27px; margin: 4px 30px 20px 0; }
.icon-button { display: inline-grid; place-content: center; width: 44px; height: 44px; border: 1px solid var(--line); border-radius: 8px; background: var(--surface); font-size: 23px; }
.dialog-close { position: absolute; top: 12px; right: 12px; }
.how-list { padding-left: 20px; font-size: 13px; }
.how-list li { padding-left: 5px; margin: 20px 0; }
.how-list p { color: var(--muted); margin-top: 4px; }
.dialog-note { color: var(--muted); font-size: 12px; border-top: 1px solid var(--line); padding-top: 16px; margin-top: 20px; }
.image-error, .storage-message, .noscript { background: var(--notice-bg); color: var(--notice); border: 1px solid var(--notice-line); border-radius: 8px; padding: 15px; font-size: 12px; }
.storage-message { position: fixed; z-index: 5; bottom: 15px; right: 15px; max-width: 350px; }
.mobile-filter-row, .mobile-apply { display: none; }
@media (max-width: 1100px) {
  .workspace { grid-template-columns: 262px minmax(0, 1fr); gap: 22px; }
  .question-header { padding: 20px; }
  .question-body { padding: 18px; }
  .question-title { font-size: 21px; }
}
@media (max-width: 800px) {
  .site-header { min-height: 66px; gap: 12px; padding: 0 18px; }
  .brand { font-size: 21px; }
  .site-header nav { gap: 0; }
  .site-header nav > a { display: none; }
  .site-header nav > button { font-size: 12px; min-height: 44px; }
  .page-shell { padding: 0 16px; }
  .intro { padding: 26px 0 24px; }
  h1 { letter-spacing: -.9px; font-size: 31px; }
  .workspace { display: block; }
  .mobile-filter-row { display: block; margin-bottom: 22px; }
  #filters-toggle { width: 100%; justify-content: flex-start; }
  #filters-toggle > span:last-child { margin-left: auto; }
  #mobile-filter-count:not(:empty) { background: var(--accent-soft); border-radius: 4px; padding: 0 6px; font-size: 11px; }
  .filters { display: none; position: static; max-height: none; margin-bottom: 24px; overflow: hidden; }
  body.filters-open .filters { display: block; }
  .filter-section { padding: 18px; }
  .topic-list { max-height: 260px; }
  .topic-row { font-size: 14px; min-height: 46px; }
  .topic-row input { width: 19px; height: 19px; }
  .topic-search input, .field select { font-size: 16px; }
  .mobile-apply { display: flex; width: calc(100% - 36px); margin: 0 18px 18px; }
  .question-header { padding: 18px; }
  .question-body { padding: 18px 12px; }
  .answer-area { padding: 20px 18px; }
  .marking-details > summary { padding: 18px; }
  .marking-content { padding: 0 12px 16px; }
  .written-footer { padding: 15px 18px; }
  .site-footer { margin-top: 12px; }
}
@media (max-width: 480px) {
  .site-header { padding: 0 14px; }
  .brand { gap: 6px; font-size: 20px; }
  .brand-mark { width: 24px; }
  .site-header nav > button { font-size: 11px; }
  .page-shell { padding: 0 12px; }
  h1 { font-size: 29px; }
  .results-toolbar { align-items: flex-start; }
  .results-toolbar h2 { font-size: 23px; }
  .ordering { width: 100%; justify-content: space-between; }
  .ordering > * { flex: 1; min-width: 0; }
  .sort-field select { font-size: 14px; }
  .question-header { padding: 16px; }
  .question-title { font-size: 21px; }
  .question-header-top { align-items: flex-start; gap: 9px; }
  .question-kind { font-size: 10px; letter-spacing: .6px; }
  .source-link { font-size: 11px; }
  .question-body { padding: 16px 8px; }
  .options { grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 7px; max-width: 300px; }
  .option { min-width: 0; height: 46px; }
  .answer-area { padding: 18px 14px; }
  .written-footer { flex-direction: column; align-items: stretch; gap: 10px; }
  .written-footer p { text-align: center; }
  .info-dialog { padding: 29px 22px; }
  .question-card { margin-bottom: 18px; }
}
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { animation: none !important; transition: none !important; scroll-behavior: auto !important; } }
@media print {
  .site-header, .intro, .filters, .mobile-filter-row, .results-toolbar, .active-filters, .feed-status, .feed-tail, .load-earlier, .site-footer, .answer-area, .written-footer, .source-link { display: none; }
  .workspace { display: block; } .page-shell { padding: 0; } .question-card { break-inside: avoid; border: 0; }
  .question-header, .question-body { padding: 10px 0; } .marking-details:not([open]) { display: none; }
  :root { color-scheme: light; --surface: #fff; --ink: #111; --muted: #555; --canvas: #fff; }
}

.icon { display: inline-block; width: 20px; height: 20px; flex-shrink: 0; fill: currentColor; vertical-align: middle; }
.brand-mark { display: inline-flex; width: 28px; color: var(--primary); }
.brand-mark .icon { width: 28px; height: 28px; }
.filter-top > .icon { color: var(--muted); }
.topic-search .icon { fill: currentColor; stroke: none; color: var(--muted); }
.source-link { display: inline-flex; align-items: center; gap: 5px; }
.source-link .icon { width: 15px; height: 15px; }
.marking-source { display: flex; justify-content: flex-end; }
.feedback-icon { width: 22px; height: 22px; }
#filters-toggle > .icon { margin-left: auto; }
.field, .sort-field { position: relative; }
select { appearance: none; }
.field::after, .sort-field::after { content: ''; position: absolute; right: 11px; bottom: 14px; width: 16px; height: 16px; background: var(--muted); mask: url('./icons/phosphor/caret-down.svg') center/contain no-repeat; pointer-events: none; }
.written-footer { justify-content: flex-end; }

.header-menu { position: relative; margin-left: auto; }
.header-menu > summary { list-style: none; cursor: pointer; }
.header-menu > summary::-webkit-details-marker { display: none; }
.header-menu[open] > summary { background: var(--soft); }
.header-menu-panel { position: absolute; z-index: 30; top: calc(100% + 9px); right: 0; width: 190px; max-width: calc(100vw - 28px); padding: 6px; border: 1px solid var(--line); border-radius: 10px; background: var(--surface); box-shadow: 0 8px 24px #0002; }
.header-menu-panel button { display: flex; align-items: center; gap: 10px; width: 100%; min-height: 44px; padding: 10px 12px; text-align: left; font-size: 14px; opacity: .65; }

.menu-about { border-top: 1px solid var(--line); margin-top: 4px; }
.menu-about > summary { cursor: pointer; padding: 11px 12px; min-height: 44px; font-size: 14px; }
.menu-about > p { margin: 0; padding: 0 12px 12px; font-size: 12px; line-height: 1.6; color: var(--muted); overflow-wrap: anywhere; }

.questions-subheader { position: sticky; top: 0; z-index: 10; background: var(--canvas); padding: 10px 0 9px; border-bottom: 1px solid var(--line); margin-bottom: 14px; }
.questions-subheader .results-toolbar { flex-wrap: nowrap; margin: 0; gap: 12px; }
.questions-subheader .results-toolbar h2 { font-size: 20px; }
.questions-subheader .eyebrow { font-size: 9px; margin-bottom: 2px; }
.questions-subheader .feed-status { border: 0; padding: 5px 0 0; font-size: 11px; }
.sort-menu { position: relative; flex-shrink: 0; }
.sort-menu > summary { list-style: none; cursor: pointer; font-size: 12px; padding: 8px 11px; min-height: 40px; }
.sort-menu > summary::-webkit-details-marker { display: none; }
.sort-menu[open] > summary > .icon { transform: rotate(180deg); }
.sort-panel { position: absolute; top: calc(100% + 6px); right: 0; width: 210px; max-width: calc(100vw - 28px); padding: 8px; background: var(--surface); border: 1px solid var(--line); border-radius: 10px; box-shadow: 0 8px 24px #0002; }
.sort-panel fieldset { border: 0; margin: 0; padding: 0; }
.sort-panel label { display: flex; align-items: center; gap: 10px; min-height: 44px; padding: 8px; font-size: 14px; cursor: pointer; border-radius: 6px; }
.sort-panel label:has(input:checked) { background: var(--accent-soft); }
.sort-panel input { accent-color: var(--primary); }
.sort-panel #shuffle { width: 100%; margin-top: 8px; border-top: 1px solid var(--line); }
@media print { .questions-subheader { display: none; } }

.subjects-back { display: inline-block; margin: 0 0 18px; font-size: 14px; color: var(--accent); }
.subject-search { display: flex; align-items: center; gap: 12px; max-width: 680px; border: 1px solid var(--line); background: var(--surface); border-radius: 10px; padding: 0 16px; }
.subject-search input { width: 100%; min-width: 0; min-height: 54px; border: 0; outline: 0; background: transparent; font-size: 16px; }
.subject-search:focus-within { outline: 2px solid var(--focus); }
.level-picker { display: flex; flex-wrap: wrap; gap: 8px; margin: 22px 0 16px; }
.level-picker button { min-height: 44px; border: 1px solid var(--line); border-radius: 8px; padding: 10px 17px; font-size: 14px; background: var(--surface); }
.level-picker button[aria-pressed=true] { background: var(--button); color: var(--on-button); border-color: var(--button); }
#subject-results { font-size: 13px; color: var(--muted); margin-bottom: 18px; }
.subject-grid { display: grid; grid-template-columns: repeat(auto-fill,minmax(240px,1fr)); gap: 16px; padding-bottom: 32px; }
.subject-tile { display: flex; flex-direction: column; align-items: flex-start; gap: 12px; padding: 22px; border: 1px solid var(--line); border-radius: 14px; background: var(--surface); text-decoration: none; min-height: 205px; }
.subject-tile > .icon { width: 28px; height: 28px; color: var(--accent); }
.subject-tile h2 { font-size: 19px; letter-spacing: -.3px; overflow-wrap: anywhere; }
.subject-level { font-size: 12px; color: var(--muted); }
.subject-availability { margin-top: auto; font-size: 12px; color: var(--muted); background: var(--soft); padding: 4px 9px; border-radius: 6px; }
.subject-tile.available { border-color: var(--accent); }
.subject-tile.available:hover { background: var(--accent-soft); }
.subject-tile.available .subject-availability { color: var(--accent); background: var(--accent-soft); }
@media(max-width:480px) { .subject-grid { grid-template-columns: 1fr; gap: 12px; } .level-picker { gap: 6px; } .level-picker button { padding: 10px 11px; font-size: 13px; } }

/* Compact paper header; sorting stays with the question filters. */
.question-view .site-header { position: sticky; top: 0; z-index: 20; display: grid; grid-template-columns: auto minmax(180px, 520px) 44px; gap: 20px; padding-top: 10px; padding-bottom: 10px; }
.question-view .site-header .header-menu { margin-left: 0; }
.header-search { position: relative; min-width: 0; width: 100%; }
.header-search .subject-search { width: 100%; }
.header-search .subject-search input { min-height: 44px; }
.header-search-results { position: absolute; top: calc(100% + 8px); left: 0; right: 0; background: var(--surface); border: 1px solid var(--control-line); border-radius: 10px; padding: 8px; box-shadow: 0 8px 24px #0002; max-height: min(420px, calc(100dvh - 160px)); overflow-y: auto; }
.header-search-results ul { list-style: none; margin: 0; padding: 0; }
.header-search-results a, .header-search-results li > span { display: flex; align-items: center; min-height: 44px; padding: 8px; font-size: 14px; text-decoration: none; overflow-wrap: anywhere; }
.header-search-results a:hover { background: var(--soft); text-decoration: underline; }
.header-search-results li > span, .header-search-results p { color: var(--muted); }
.header-search-results p { font-size: 14px; padding: 8px; }
.header-search-results > a { border-top: 1px solid var(--line); color: var(--accent); }
.landing-introduction { display: grid; grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr); align-items: center; gap: 32px; }
.landing-introduction > p { color: var(--muted); font-size: 15px; line-height: 1.7; max-width: 560px; }
.menu-about h2 { font-size: 14px; letter-spacing: 0; padding: 12px; }
.sort-section .sort-menu > summary { width: 100%; justify-content: space-between; }
.sort-section .sort-panel { position: absolute; z-index: 10; top: calc(100% + 6px); right: 0; width: 100%; max-width: none; margin: 0; max-height: min(360px, calc(100dvh - 160px)); overflow-y: auto; }
#shuffle-message.toast { position: fixed; z-index: 60; bottom: max(20px, env(safe-area-inset-bottom)); left: 50%; transform: translateX(-50%); max-width: calc(100vw - 32px); padding: 12px 20px; border: 1px solid var(--control-line); border-radius: 10px; background: var(--surface); color: var(--ink); box-shadow: 0 6px 24px #0003; font-size: 14px; }
.question-view .page-shell { padding-top: 20px; }
.question-view .filters { top: calc(var(--sticky-height) + 16px); max-height: calc(100dvh - var(--sticky-height) - 32px); }
.question-card { scroll-margin-top: calc(var(--sticky-height) + 16px); }
#shuffle-message:empty, #topic-results:empty { display: none; }
#shuffle-message { font-size: 13px; color: var(--accent); padding-top: 5px; }
#topic-results { margin: 8px 0; }
.skip-link { z-index: 100; }
.small-link { min-height: 44px; min-width: 44px; }
.source-link { min-height: 44px; padding: 6px 0; }
.sort-menu > summary { min-height: 44px; }
select, .subject-search, .topic-search, .button-outline, .icon-button, .option, .level-picker button { border-color: var(--control-line); }
input::placeholder { color: var(--muted); opacity: 1; }
.scan-link:focus-visible { outline-offset: -4px; }
@media (max-width: 800px) {
  .question-view .site-header { gap: 0 8px; padding-top: 8px; }
  .question-view .filters { position: static; max-height: none; }
  .mobile-filter-row { margin-bottom: 14px; }
}
@media (max-height: 480px) { .question-view .site-header { position: relative; } .question-view .filters { position: static; max-height: none; } html { scroll-padding-top: 16px; } }
@media (forced-colors: active) { .option:has(input:checked), .level-picker button[aria-pressed=true] { outline: 2px solid Highlight; } .icon { forced-color-adjust: auto; } }

.header-menu-panel, .sort-panel { max-height: calc(100dvh - 80px); overflow-y: auto; }

@media (max-width: 800px) {
  .question-view .site-header { grid-template-columns: minmax(0, 1fr) 44px; gap: 8px 12px; padding-top: 10px; padding-bottom: 10px; }
  .brand { font-size: 22px; letter-spacing: 0; line-height: 1.2; gap: 9px; }
  .brand-mark, .brand-mark .icon { width: 28px; height: 28px; flex-shrink: 0; }
  .question-view .header-search { grid-column: 1 / -1; grid-row: 2; }
  .question-view .header-menu { grid-column: 2; grid-row: 1; }
  .landing-introduction { grid-template-columns: 1fr; gap: 16px; }
}
@media (max-height: 480px) { .question-view .site-header { position: relative; } }
@media print { .toast, .header-search { display: none; } }