:root {
  --ink: #1a1a1a;
  --muted: #66625d;
  --paper: #fafaf7;
  --paper-deep: #f5f3f0;
  --surface: #ffffff;
  --accent: #9a3412;
  --accent-hover: #7c2d12;
  --accent-soft: #fff8f3;
  --rule: #d4d4d4;
  --rule-dark: #aaa7a2;
  --green: #166534;
  --green-soft: #ecfdf5;
  --red: #991b1b;
  --red-soft: #fef2f2;
  --amber: #854d0e;
  --amber-soft: #fffbea;
  --radius-lg: 8px;
  --radius-md: 6px;
  --radius-sm: 4px;
  --font-serif: "Noto Serif TC", "PingFang TC", "Songti TC", "Times New Roman", serif;
  color: var(--ink);
  background: var(--paper);
  font-family: var(--font-serif);
  font-synthesis: none;
}

* { box-sizing: border-box; }

html { min-width: 320px; background: var(--paper-deep); }

body {
  min-height: 100vh;
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: 0.015em;
}

button, input, select { font: inherit; }
button { -webkit-tap-highlight-color: transparent; }

button:focus-visible,
input:focus-visible,
select:focus-visible,
a:focus-visible {
  outline: 3px solid rgba(154, 52, 18, 0.34);
  outline-offset: 2px;
}

[hidden] { display: none !important; }

.skip-link {
  position: fixed;
  z-index: 100;
  top: 0.75rem;
  left: 0.75rem;
  min-height: 44px;
  padding: 0.5rem 0.9rem;
  border: 1px solid var(--accent);
  border-radius: var(--radius-sm);
  color: var(--accent);
  background: var(--surface);
  transform: translateY(-180%);
  transition: transform 140ms ease;
}

.skip-link:focus { transform: translateY(0); }

.site-shell {
  min-height: 100vh;
  display: grid;
  grid-template-columns: minmax(250px, 310px) minmax(0, 1fr);
}

.side-panel {
  position: sticky;
  top: 0;
  height: 100vh;
  overflow: auto;
  display: flex;
  flex-direction: column;
  gap: 2rem;
  padding: clamp(2rem, 4vw, 3.5rem) clamp(1.5rem, 2.8vw, 2.5rem) 2rem;
  border-right: 1px solid var(--rule);
  color: var(--ink);
  background: var(--paper-deep);
}

.brand-mark {
  width: 70px;
  height: 24px;
  display: flex;
  align-items: center;
  gap: 5px;
  margin-bottom: 2.5rem;
}

.brand-mark span { width: 3px; border-radius: 1px; background: var(--accent); }
.brand-mark span:nth-child(1), .brand-mark span:nth-child(5) { height: 4px; }
.brand-mark span:nth-child(2), .brand-mark span:nth-child(4) { height: 11px; }
.brand-mark span:nth-child(3) { height: 24px; transform: skewX(-14deg); }

.eyebrow,
.section-kicker,
.card-label,
.answer-label {
  margin: 0;
  color: var(--accent);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.side-panel h1 {
  margin: 0.35rem 0 0;
  color: var(--ink);
  font-size: clamp(2.1rem, 3.5vw, 3.15rem);
  line-height: 1.15;
  letter-spacing: 0.02em;
}

.side-copy { max-width: 17rem; margin: 1.2rem 0 0; color: var(--muted); line-height: 1.85; }

.privacy-note {
  display: flex;
  gap: 0.75rem;
  align-items: flex-start;
  padding: 0.9rem 1rem;
  border: 1px solid var(--rule);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius-md);
  background: var(--accent-soft);
}

.privacy-note strong { font-size: 0.92rem; }
.privacy-note p { margin: 0.1rem 0 0; color: var(--muted); font-size: 0.8rem; line-height: 1.55; }
.lock-icon { color: var(--accent); font-size: 0.65rem; transform: translateY(0.35rem); }

.side-stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.75rem;
  margin: auto 0 0;
}

.side-stats div { padding-top: 0.75rem; border-top: 1px solid var(--rule); }
.side-stats dt { color: var(--muted); font-size: 0.72rem; line-height: 1.35; }
.side-stats dd {
  margin: 0.12rem 0 0;
  color: var(--accent);
  font-family: "Times New Roman", var(--font-serif);
  font-size: 1.5rem;
  font-weight: 700;
}
.side-stats small { display: block; margin-top: 0.1rem; color: var(--muted); font-size: 0.62rem; line-height: 1.35; }

.source-note { margin: 0; color: #817d77; font-size: 0.72rem; }

.main-panel { min-width: 0; padding: clamp(1.5rem, 4vw, 4rem); background: var(--paper); }
.view { width: min(100%, 940px); margin-inline: auto; }
.mobile-header { display: none; }

.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;
}

.site-header {
  position: sticky;
  z-index: 40;
  top: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  width: 100%;
  padding: 0.7rem clamp(1rem, 3vw, 2.5rem);
  border-bottom: 1px solid var(--rule);
  background: var(--surface);
  font-size: 0.86rem;
}

.site-header .breadcrumb { min-width: 0; color: var(--muted); }
.site-header .toolbar { display: flex; flex-wrap: wrap; align-items: center; justify-content: flex-end; gap: 0.5rem; }
.site-header button,
.public-chip,
.algorithm-chip,
.deadline-chip {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  padding: 0.35rem 0.75rem;
  border: 1px solid var(--rule);
  border-radius: var(--radius-sm);
  color: var(--ink);
  background: var(--surface);
  font-size: 0.82rem;
}
.public-chip { color: var(--green); border-color: #86d6ad; background: var(--green-soft); }
.algorithm-chip { color: var(--accent); border-color: #d6b7aa; background: var(--accent-soft); }
.deadline-chip { color: var(--amber); border-color: #e5bd69; background: var(--amber-soft); }

.home-heading {
  display: flex;
  justify-content: space-between;
  gap: 2rem;
  align-items: flex-end;
  margin-bottom: clamp(1.75rem, 4vw, 3rem);
  padding-bottom: 1.2rem;
  border-bottom: 1px solid var(--rule);
}

.home-heading h2 {
  max-width: 700px;
  margin: 0.5rem 0 0;
  font-size: clamp(2rem, 4.3vw, 3.5rem);
  line-height: 1.3;
  letter-spacing: 0.01em;
}

.sprint-panel {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
  gap: 1rem 2rem;
  align-items: center;
  margin-bottom: 1rem;
  padding: 1rem 1.15rem;
  border: 1px solid #e5bd69;
  border-left: 4px solid var(--amber);
  border-radius: var(--radius-md);
  background: var(--amber-soft);
}
.sprint-panel h3 { margin: 0.12rem 0 0; font-size: 1.05rem; }
.sprint-panel strong { color: var(--amber); }
.sprint-panel p:not(.section-kicker) { margin: 0.12rem 0 0; color: var(--muted); font-size: 0.8rem; line-height: 1.55; }

.date-copy { flex: 0 0 auto; margin: 0 0 0.35rem; color: var(--muted); font-size: 0.86rem; }

.review-filter-control {
  min-width: 0;
  display: grid;
  gap: 0.3rem;
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 700;
}
.review-filter-control select,
.browse-controls select {
  width: 100%;
  max-width: 100%;
  min-height: 48px;
  padding: 0.55rem 2.25rem 0.55rem 0.75rem;
  border: 1px solid var(--rule-dark);
  border-radius: var(--radius-sm);
  color: var(--ink);
  background: var(--surface);
}
.review-filter-panel {
  display: grid;
  grid-template-columns: minmax(180px, 280px) minmax(0, 1fr);
  gap: 0.75rem 1rem;
  align-items: end;
  margin-bottom: 1rem;
  padding: 0.8rem 0.9rem;
  border: 1px solid var(--rule);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius-md);
  background: var(--paper-deep);
}
.review-filter-panel[hidden] { display: none; }
.review-filter-panel p {
  margin: 0 0 0.7rem;
  color: var(--muted);
  font-size: 0.78rem;
  line-height: 1.55;
}

.mode-grid { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 1rem; }

.mode-card {
  min-height: 330px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: clamp(1.35rem, 3vw, 2.2rem);
  border: 1px solid var(--rule);
  border-radius: var(--radius-lg);
  background: var(--surface);
}

.mode-card--exam { border-top: 4px solid var(--accent); }
.mode-card--review { background: #fffdfa; }
.mode-card--browse { grid-column: 1 / -1; min-height: 250px; background: var(--paper-deep); }
.mode-number {
  align-self: flex-end;
  color: var(--accent);
  font-family: "Times New Roman", serif;
  font-size: 2rem;
  font-weight: 700;
  line-height: 1;
  opacity: 0.48;
}
.mode-card .card-label { color: var(--accent); }
.mode-card h3 { max-width: 18ch; margin: 0.35rem 0 0.65rem; font-size: clamp(1.45rem, 2.4vw, 2rem); line-height: 1.35; }
.mode-card p:not(.card-label) { max-width: 36rem; margin: 0; color: var(--muted); }
.mode-note { font-size: 0.78rem; line-height: 1.55; }

.action-row,
.result-actions,
.utility-actions { display: flex; flex-wrap: wrap; gap: 0.65rem; }

.formal-exam-entry {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 0.7rem 1rem;
  align-items: center;
  margin-top: 1.2rem;
  padding-top: 1.1rem;
  border-top: 1px solid var(--rule);
}
.formal-exam-entry strong { display: block; color: var(--ink); font-size: 0.95rem; }
.formal-exam-entry p { margin-top: 0.1rem !important; font-size: 0.78rem; line-height: 1.55; }
.formal-exam-entry small { grid-column: 1 / -1; color: var(--muted); font-size: 0.7rem; line-height: 1.55; }

.button,
.text-button,
.icon-button,
.flag-button,
.rating-grid button,
.option-button { border: 0; cursor: pointer; }

.button {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  padding: 0.6rem 1rem;
  border: 1px solid var(--rule-dark);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 700;
  transition: color 120ms ease, background 120ms ease, border-color 120ms ease;
}

.button:hover { border-color: var(--accent); }
.button:disabled { cursor: not-allowed; opacity: 0.46; }
.button--light, .button--secondary { color: var(--ink); background: var(--surface); }
.button--ghost-light { color: var(--accent); border-color: #d7aa98; background: var(--accent-soft); }
.button--dark { color: #fff; border-color: var(--ink); background: var(--ink); }
.button--dark:hover { border-color: #333; background: #333; }
.button--accent { color: #fff; border-color: var(--accent); background: var(--accent); }
.button--accent:hover { border-color: var(--accent-hover); background: var(--accent-hover); }

.utility-panel {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
  margin-top: 1rem;
  padding: 1.15rem 1.25rem;
  border: 1px solid var(--rule);
  border-radius: var(--radius-md);
  background: var(--paper-deep);
}

.utility-panel h3, .list-heading h3 { margin: 0.12rem 0 0; font-size: 1.05rem; }
.utility-panel p:not(.section-kicker), .list-heading p { margin: 0.12rem 0 0; color: var(--muted); font-size: 0.84rem; }
.text-button {
  min-height: 44px;
  padding: 0.35rem 0.25rem;
  color: var(--accent);
  background: transparent;
  font-weight: 700;
  text-decoration: underline;
  text-decoration-color: rgba(154, 52, 18, 0.35);
  text-underline-offset: 4px;
}

.task-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.15rem;
  padding-bottom: 0.85rem;
  border-bottom: 1px solid var(--rule);
}

.icon-button {
  width: 46px;
  height: 46px;
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  border: 1px solid var(--rule);
  border-radius: 50%;
  color: var(--ink);
  background: var(--surface);
  font-size: 1.45rem;
}
.icon-button:hover { border-color: var(--accent); color: var(--accent); }
.task-progress-wrap { min-width: 0; flex: 1; }

.task-progress-copy,
.review-header-copy,
.question-meta,
.list-heading { display: flex; align-items: center; justify-content: space-between; gap: 1rem; }
.question-actions { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 0.45rem; }

.task-progress-copy,
.review-header-copy { margin-bottom: 0.35rem; color: var(--muted); font-size: 0.84rem; font-weight: 700; }
.timer { color: var(--accent); font-family: "Times New Roman", serif; font-variant-numeric: tabular-nums; }
.progress-track { height: 5px; overflow: hidden; border-radius: 2px; background: #e7e5e1; }
.progress-fill { width: 10%; height: 100%; border-radius: inherit; background: var(--accent); transition: width 180ms ease; }

.question-card {
  padding: clamp(1.3rem, 4vw, 2.5rem);
  border: 1px solid var(--rule);
  border-radius: var(--radius-lg);
  background: var(--surface);
}

.question-meta {
  padding-bottom: 0.75rem;
  border-bottom: 1px dashed var(--rule);
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.flag-button {
  min-height: 44px;
  padding: 0.35rem 0.65rem;
  border: 1px solid var(--rule);
  border-radius: var(--radius-sm);
  color: var(--muted);
  background: var(--paper-deep);
  font-size: 0.78rem;
  font-weight: 700;
}
.flag-button[aria-pressed="true"] { color: var(--amber); border-color: #f0c76f; background: var(--amber-soft); }
.flag-button:disabled { cursor: not-allowed; opacity: 0.45; }
.review-meta-actions { display: flex; flex-wrap: wrap; align-items: center; justify-content: flex-end; gap: 0.45rem; }
.pattern-badge {
  min-height: 32px;
  display: inline-flex;
  align-items: center;
  padding: 0.2rem 0.55rem;
  border: 1px solid #e5bd69;
  border-radius: 999px;
  color: var(--amber);
  background: var(--amber-soft);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.03em;
  white-space: nowrap;
}

.question-stem {
  margin: 1.2rem 0 1.4rem;
  font-size: clamp(1.2rem, 2.15vw, 1.65rem);
  line-height: 1.7;
  letter-spacing: 0.01em;
  white-space: pre-line;
}

.option-list { display: grid; gap: 0.45rem; }
.option-button {
  width: 100%;
  min-height: 52px;
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 0.75rem;
  align-items: center;
  padding: 0.7rem 0.8rem;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  color: var(--ink);
  background: var(--surface);
  text-align: left;
  transition: color 120ms ease, border-color 120ms ease, background 120ms ease;
}
.option-button:hover { border-color: var(--rule); background: var(--paper); }
.option-button[aria-pressed="true"], .option-button.is-selected { border-color: #d4a574; background: var(--accent-soft); }
.option-button.is-correct { border-color: #10b981; background: var(--green-soft); }
.option-button.is-wrong { border-color: #ef4444; background: var(--red-soft); }
.option-button:disabled { cursor: default; opacity: 1; }

.option-key {
  width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  border: 1px solid var(--rule);
  border-radius: var(--radius-sm);
  color: var(--ink);
  background: var(--paper-deep);
  font-family: "Times New Roman", serif;
  font-weight: 700;
}
.option-button[aria-pressed="true"] .option-key, .option-button.is-selected .option-key { color: #fff; border-color: var(--accent); background: var(--accent); }
.option-button.is-correct .option-key { color: #fff; border-color: var(--green); background: var(--green); }
.option-button.is-wrong .option-key { color: #fff; border-color: var(--red); background: var(--red); }

.task-footer { display: flex; justify-content: flex-end; gap: 0.65rem; margin-top: 1rem; }

.result-hero {
  margin-bottom: 2.2rem;
  padding: clamp(1.5rem, 4vw, 2.5rem);
  border: 1px solid var(--rule);
  border-top: 4px solid var(--accent);
  border-radius: var(--radius-lg);
  color: var(--ink);
  background: var(--surface);
}
.result-hero .section-kicker { color: var(--accent); }
.result-hero h2 {
  margin: 0.15rem 0 0;
  color: var(--accent);
  font-family: "Times New Roman", var(--font-serif);
  font-size: clamp(4rem, 10vw, 7rem);
  line-height: 1;
  letter-spacing: -0.04em;
}
.result-hero h2 small { margin-left: 0.25rem; color: var(--ink); font-size: 1rem; letter-spacing: 0; }
.result-hero > p:not(.section-kicker) { margin: 0.85rem 0 1.35rem; color: var(--muted); }

.result-breakdown {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.7rem;
  margin: 0 0 1.3rem;
}
.result-breakdown > div {
  display: grid;
  gap: 0.15rem;
  padding: 0.8rem 0.9rem;
  border: 1px solid var(--rule);
  border-radius: var(--radius-sm);
  background: var(--paper-deep);
}
.result-breakdown span { color: var(--muted); font-size: 0.75rem; }
.result-breakdown strong { color: var(--accent); font-size: 1.15rem; }
.result-breakdown small { color: var(--muted); font-size: 0.74rem; }
.result-breakdown > p {
  grid-column: 1 / -1;
  margin: 0 !important;
  color: var(--muted);
  font-size: 0.72rem;
  line-height: 1.6;
}

.review-list { display: grid; gap: 0.8rem; margin-top: 1rem; }
.review-item {
  padding: 1rem 1.1rem;
  border: 1px solid var(--rule);
  border-left: 4px solid var(--green);
  border-radius: var(--radius-md);
  background: var(--surface);
}
.review-item.is-wrong { border-left-color: var(--red); }
.review-item.is-blank { border-left-color: var(--amber); }
.review-item h4 { margin: 0.18rem 0 0.6rem; font-size: 1rem; line-height: 1.65; }
.review-item p { margin: 0.15rem 0; color: var(--muted); font-size: 0.84rem; }
.result-options { display: grid; gap: 0.3rem; margin: 0.7rem 0; }
.result-option {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.5rem 0.65rem;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  color: var(--muted);
  background: var(--paper-deep);
  font-size: 0.84rem;
}
.result-option.is-correct { color: var(--green); border-color: #86d6ad; background: var(--green-soft); }
.result-option.is-wrong { color: var(--red); border-color: #f3a6a6; background: var(--red-soft); }
.result-option small { flex: 0 0 auto; font-weight: 700; }

.question-card--review { min-height: 480px; }
.recall-label { color: var(--muted); }
.reveal-button { width: 100%; margin-top: 0.8rem; }
.answer-panel { margin-top: 1.2rem; padding-top: 1.25rem; border-top: 1px solid var(--rule); }
.answer-panel > strong { display: block; margin: 0.2rem 0 0.55rem; color: var(--accent); font-size: 1.4rem; }
.reference-copy { margin: 0; color: var(--muted); font-size: 0.86rem; }
.rating-prompt { margin-top: 1.35rem; }
.rating-prompt > p { margin: 0 0 0.55rem; font-weight: 700; }
.rating-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 0.5rem; }
.rating-grid button {
  min-height: 72px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 0.5rem;
  border: 1px solid var(--rule);
  border-radius: var(--radius-sm);
  color: var(--ink);
  background: var(--surface);
}
.rating-grid button:hover { color: var(--accent); border-color: var(--accent); background: var(--accent-soft); }
.rating-grid span { color: var(--muted); font-size: 0.7rem; }

.empty-state {
  min-height: 480px;
  display: grid;
  place-content: center;
  justify-items: center;
  padding: 2rem;
  border: 1px solid var(--rule);
  border-radius: var(--radius-lg);
  background: var(--surface);
  text-align: center;
}
.completion-mark {
  width: 68px;
  height: 68px;
  display: grid;
  place-items: center;
  border: 1px solid #86d6ad;
  border-radius: 50%;
  color: var(--green);
  background: var(--green-soft);
  font-size: 1.8rem;
  font-weight: 700;
}
.empty-state h2 { margin: 0.9rem 0 0.2rem; font-size: 1.85rem; }
.empty-state p { max-width: 26rem; margin: 0 0 1.15rem; color: var(--muted); }
.empty-state .waiting-copy {
  padding: 0.55rem 0.75rem;
  border: 1px solid #d6b7aa;
  border-radius: var(--radius-sm);
  color: var(--accent);
  background: var(--accent-soft);
  font-size: 0.88rem;
}

.browse-header .review-header-copy { min-width: 0; flex: 1; }
.browse-heading { margin-bottom: 1rem; }
.browse-heading h2 { margin: 0.15rem 0 0; }
.browse-filter-panel {
  margin-bottom: 1rem;
  padding: 1rem;
  border: 1px solid var(--rule);
  border-radius: var(--radius-md);
  background: var(--paper-deep);
}
.browse-controls {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.75rem;
}
.browse-controls label {
  min-width: 0;
  display: grid;
  gap: 0.3rem;
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 700;
}
.browse-filter-summary {
  margin: 0.75rem 0 0;
  color: var(--muted);
  font-size: 0.82rem;
}
.browse-list { display: grid; gap: 1rem; }
.browse-card { min-width: 0; }
.browse-card .question-stem { margin-bottom: 1rem; font-size: clamp(1.05rem, 1.8vw, 1.35rem); }
.browse-options { display: grid; gap: 0.4rem; margin: 0; padding: 0; list-style: none; }
.browse-options li,
.browse-option-button {
  min-width: 0;
  display: grid;
  grid-template-columns: 32px minmax(0, 1fr);
  gap: 0.7rem;
  align-items: start;
  padding: 0.65rem 0.7rem;
  border-radius: var(--radius-sm);
  background: var(--paper-deep);
  overflow-wrap: anywhere;
}
.browse-option-button {
  width: 100%;
  min-height: 48px;
  border: 1px solid transparent;
  color: var(--ink);
  text-align: left;
  cursor: pointer;
}
.browse-option-button:hover { border-color: var(--rule-dark); background: var(--paper); }
.browse-option-button[aria-pressed="true"],
.browse-option-button.is-selected { border-color: #d4a574; background: var(--accent-soft); }
.browse-option-button.is-correct { border-color: #86d6ad; background: var(--green-soft); }
.browse-option-button.is-wrong { border-color: #f3a6a6; background: var(--red-soft); }
.browse-option-button:disabled { cursor: default; opacity: 1; }
.browse-options strong { color: var(--accent); font-family: "Times New Roman", serif; text-align: center; }
.browse-reference { margin-top: 1rem; overflow-wrap: anywhere; }
.browse-answer-toggle,
.browse-confirm { width: 100%; min-height: 48px; margin-top: 0.8rem; }
.browse-confirm:disabled { cursor: not-allowed; opacity: 0.55; }
.browse-card-status,
.browse-status {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 0.2rem 0.55rem;
  border: 1px solid var(--rule-dark);
  border-radius: 999px;
  color: var(--muted);
  background: var(--surface);
  font-size: 0.72rem;
  font-weight: 700;
}
.browse-card-status.is-learned,
.browse-status.is-learned { color: var(--green); border-color: #86d6ad; background: var(--green-soft); }
.browse-card-status.is-wrong,
.browse-status.is-wrong { color: var(--red); border-color: #f3a6a6; background: var(--red-soft); }
.browse-answer {
  margin: 0.7rem 0 0;
  padding: 0.75rem 0.9rem;
  border: 1px solid #86d6ad;
  border-radius: var(--radius-sm);
  color: var(--green);
  background: var(--green-soft);
  font-weight: 700;
}
.browse-result,
.browse-error {
  margin: 0.7rem 0 0;
  padding: 0.75rem 0.9rem;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  font-weight: 700;
}
.browse-result { color: var(--green); border: 1px solid #86d6ad; background: var(--green-soft); }
.browse-result.is-wrong,
.browse-error { color: var(--red); border: 1px solid #f3a6a6; background: var(--red-soft); }
.browse-empty {
  margin: 1rem 0;
  padding: clamp(1.25rem, 3vw, 2rem);
  border: 1px dashed var(--rule-dark);
  border-radius: var(--radius-md);
  background: var(--surface);
  text-align: center;
}
.browse-empty strong { font-size: 1.05rem; }
.browse-empty p { margin: 0.35rem 0 0; color: var(--muted); font-size: 0.86rem; }

.site-credit {
  display: grid;
  grid-template-columns: minmax(210px, 0.75fr) minmax(0, 1.6fr);
  gap: 1rem;
  align-items: center;
  margin-top: clamp(2rem, 5vw, 3.5rem);
  padding: 1rem 1.1rem;
  border: 1px solid var(--rule);
  border-top: 3px solid var(--accent);
  border-radius: var(--radius-md);
  background: var(--paper-deep);
}
.site-credit__brand {
  min-width: 0;
  min-height: 52px;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--ink);
  text-decoration: none;
}
.site-credit__brand:hover strong { color: var(--accent); }
.site-credit__avatar {
  width: 40px;
  height: 40px;
  flex: 0 0 40px;
  border: 1px solid var(--rule-dark);
  border-radius: 50%;
  background: var(--surface);
  object-fit: cover;
}
.site-credit__brand span { min-width: 0; display: grid; gap: 0.08rem; }
.site-credit__brand small { color: var(--muted); font-size: 0.7rem; }
.site-credit__brand strong { font-size: 0.92rem; transition: color 120ms ease; }
.site-credit__notice {
  min-width: 0;
  padding-left: 1rem;
  border-left: 1px solid var(--rule);
}
.site-credit__notice strong { color: var(--accent); font-size: 0.82rem; }
.site-credit__notice p {
  margin: 0.2rem 0 0;
  color: var(--muted);
  font-size: 0.76rem;
  line-height: 1.65;
}

.toast {
  position: fixed;
  z-index: 50;
  right: 1rem;
  bottom: 1rem;
  max-width: min(360px, calc(100vw - 2rem));
  padding: 0.75rem 0.9rem;
  border: 1px solid var(--ink);
  border-radius: var(--radius-sm);
  color: #fff;
  background: var(--ink);
  font-size: 0.86rem;
  font-weight: 700;
}

@media (max-width: 820px) {
  .site-shell { display: block; }
  .side-panel { display: none; }
  .main-panel { padding: 1rem; }
  .site-header {
    padding: 0.65rem 1rem;
  }
  .site-header .breadcrumb { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
  .mobile-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    margin: -1rem -1rem 2rem;
    padding: 0.75rem 1rem;
    border-bottom: 1px solid var(--rule);
    background: var(--surface);
  }
  .mobile-header strong { display: block; margin-top: -0.1rem; color: var(--ink); font-size: 1.05rem; }
  .status-pill {
    padding: 0.25rem 0.55rem;
    border: 1px solid #86d6ad;
    border-radius: var(--radius-sm);
    color: var(--green);
    background: var(--green-soft);
    font-size: 0.72rem;
    font-weight: 700;
  }
  .home-heading { display: block; margin-bottom: 1.4rem; }
  .home-heading h2 { font-size: clamp(1.85rem, 8.5vw, 2.75rem); }
  .date-copy { margin-top: 0.65rem; }
  .sprint-panel { grid-template-columns: 1fr; gap: 0.55rem; }
  .mode-grid { grid-template-columns: 1fr; }
  .mode-card { min-height: 290px; }
  .mode-card--browse { min-height: 230px; }
  .formal-exam-entry { grid-template-columns: 1fr; }
  .formal-exam-entry small { grid-column: auto; }
  .formal-exam-entry .button { width: 100%; }
  .utility-panel { align-items: flex-start; flex-direction: column; gap: 0.8rem; }
  .site-credit { grid-template-columns: 1fr; align-items: stretch; }
  .site-credit__notice { padding: 0.85rem 0 0; border-top: 1px solid var(--rule); border-left: 0; }
  .review-filter-panel { grid-template-columns: 1fr; align-items: stretch; }
  .review-filter-panel p { margin: 0; }
  .browse-controls { grid-template-columns: 1fr; }
  .question-card { padding: 1.2rem; }
  .task-footer {
    position: sticky;
    bottom: 0;
    z-index: 10;
    margin: 1rem -1rem -1rem;
    padding: 0.75rem 1rem calc(0.75rem + env(safe-area-inset-bottom));
    border-top: 1px solid var(--rule);
    background: rgba(250, 250, 247, 0.96);
  }
  .task-footer .button { flex: 1; }
  .rating-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 480px) {
  .main-panel { padding: 0.8rem; }
  .site-header { padding: 0.6rem 0.8rem; }
  .site-header .breadcrumb { display: none; }
  .site-header .toolbar { width: 100%; justify-content: space-between; }
  .site-header .toolbar > span { flex: 1 1 auto; justify-content: center; padding-inline: 0.45rem; font-size: 0.72rem; }
  .mobile-header { margin: -0.8rem -0.8rem 1.6rem; padding: 0.7rem 0.8rem; }
  .mode-card { min-height: 270px; padding: 1.25rem; }
  .mode-card--browse { min-height: 230px; }
  .site-credit { padding: 0.9rem; }
  .review-filter-panel { padding: 0.75rem; }
  .review-filter-control,
  .review-filter-control select { width: 100%; min-width: 0; }
  .action-row, .result-actions { display: grid; }
  .action-row .button, .result-actions .button { width: 100%; }
  .question-meta { align-items: flex-start; }
  .review-meta-actions { align-items: flex-end; flex-direction: column; }
  .question-actions { flex: 0 0 auto; }
  .question-stem { font-size: 1.1rem; line-height: 1.75; }
  .option-button { grid-template-columns: 32px minmax(0, 1fr); padding: 0.65rem 0.55rem; }
  .task-footer { margin-right: -0.8rem; margin-left: -0.8rem; }
  .result-option { display: block; }
  .result-option small { display: block; margin-top: 0.15rem; }
  .list-heading { display: block; }
  .result-hero { padding: 1.3rem; }
  .result-breakdown { grid-template-columns: 1fr; }
  .result-breakdown > p { grid-column: auto; }
  .browse-header .review-header-copy { align-items: flex-start; flex-direction: column; gap: 0.15rem; }
  .browse-card { padding: 1rem; }
  .browse-footer { margin-right: -0.8rem; margin-left: -0.8rem; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}