/* ──────────────────────────────────────────────────────────────
   LEXICON — bilingual technical dictionary
   Aesthetic: editorial reference book · cream paper · vermilion accent
   ────────────────────────────────────────────────────────────── */

@import url('https://fonts.googleapis.com/css2?family=Fraunces:ital,opsz,wght,SOFT,WONK@0,9..144,300..900,0..100,0..1;1,9..144,300..900,0..100,0..1&family=Newsreader:ital,opsz,wght@0,6..72,300..700;1,6..72,300..700&family=JetBrains+Mono:wght@300..700&family=Noto+Serif+SC:wght@400..700&display=swap');

/* Change html font-size (currently 16px) to rescale the entire UI. */
:root {
  --paper:        #f4ecd8;
  --paper-2:      #ece2c7;
  --paper-deep:   #e3d6b3;
  --ink:          #1a1414;
  --ink-soft:     #3a342f;
  --ink-mute:     #6b6258;
  --ink-light:    #8c8275;
  --rule:         #1a1414;
  --vermilion:    #b9351b;
  --vermilion-dk: #8a2510;
  --moss:         #4a5a3a;
  --gold:         #a07a2c;

  --serif-d:      'Fraunces', ui-serif, Georgia, serif;
  --serif:        'Newsreader', ui-serif, Georgia, serif;
  --mono:         'JetBrains Mono', ui-monospace, 'SF Mono', Menlo, monospace;
  --cn:           'Noto Serif SC', 'Songti SC', 'STSong', serif;

  --max:          123.75rem;
  --gutter:       clamp(1.875rem, 4vw, 6rem);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; overflow-x: hidden; }
body {
  font-family: var(--serif);
  font-feature-settings: "kern", "liga", "onum";
  background: var(--paper);
  color: var(--ink);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  min-height: 100vh;
  overflow-x: hidden;
  background-image:
    radial-gradient(at 12% 8%,  rgba(185,53,27,0.05) 0, transparent 38%),
    radial-gradient(at 88% 78%, rgba(74,90,58,0.04) 0, transparent 42%),
    radial-gradient(at 50% 100%, rgba(160,122,44,0.05) 0, transparent 50%);
  background-attachment: fixed;
  position: relative;
}
body::before {
  content: '';
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 1;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 240 240' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.92' numOctaves='2'/%3E%3CfeColorMatrix values='0 0 0 0 0.1 0 0 0 0 0.08 0 0 0 0 0.07 0 0 0 0.16 0'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  opacity: 0.5;
  mix-blend-mode: multiply;
}

::selection { background: var(--vermilion); color: var(--paper); }

/* ── Layout shell ─────────────────────────────────────────── */
.shell { position: relative; z-index: 2; }
.container {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

/* ── Top bar ──────────────────────────────────────────────── */
.topbar {
  border-bottom: 1px solid var(--rule);
  padding: 0.875rem 0;
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--paper);
  background-image:
    linear-gradient(180deg, var(--paper) 92%, rgba(244,236,216,0.85) 100%);
  backdrop-filter: saturate(140%);
}
.topbar .container {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
  align-items: center;
  gap: 2rem;
}
.topbar .brand { justify-self: start; }
.topbar .search-wrap { justify-self: center; }
.topbar .meta { justify-self: end; }
.brand {
  font-family: var(--serif-d);
  font-variation-settings: 'opsz' 144, 'SOFT' 100, 'WONK' 1;
  font-weight: 800;
  font-size: clamp(1.75rem, 3.4vw, 2.75rem);
  letter-spacing: -0.04em;
  line-height: 0.95;
  color: var(--ink);
  text-decoration: none;
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
}
.brand .dot { color: var(--vermilion); font-style: italic; }
.brand small {
  font-family: var(--mono);
  font-size: 0.6875rem;
  font-weight: 400;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--ink-mute);
  align-self: center;
  padding-left: 0.875rem;
  border-left: 1px solid var(--ink-light);
}
.topbar .meta {
  font-family: var(--mono);
  font-size: 0.8125rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-mute);
  text-align: right;
  line-height: 1.65;
  align-self: center;
}
.topbar .meta b { color: var(--vermilion); font-weight: 600; }

.search-wrap {
  position: relative;
  align-self: center;
}
.search {
  width: min(22.5rem, 36vw);
  font-family: var(--serif);
  font-size: 1rem;
  padding: 0.625rem 0.875rem 0.625rem 2.25rem;
  border: 1px solid var(--ink);
  background: var(--paper-2);
  color: var(--ink);
  border-radius: 0;
  outline: none;
  transition: background 0.2s ease, border-color 0.2s ease;
}
.search:focus { background: var(--paper); border-color: var(--vermilion); }
.search-wrap::before {
  content: '⌕';
  position: absolute;
  left: 0.75rem;
  top: 50%;
  transform: translateY(-50%);
  font-size: 1.125rem;
  color: var(--ink);
  font-family: var(--serif-d);
  font-weight: 700;
  pointer-events: none;
}

/* ── Hero ─────────────────────────────────────────────────── */
.hero {
  padding: clamp(3.75rem, 6vw, 7.5rem) 0 clamp(3rem, 5vw, 5.625rem);
  border-bottom: 1px solid var(--rule);
  position: relative;
}
.hero-inner {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
  gap: clamp(2.625rem, 5vw, 7.5rem);
  align-items: center;
}
.hero-inner > div { min-width: 0; }
.hero-eyebrow {
  font-family: var(--mono);
  font-size: 1rem;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  color: var(--vermilion);
  margin-bottom: 1.6875rem;
  display: flex;
  align-items: center;
  gap: 1.3125rem;
}
.hero-eyebrow::before, .hero-eyebrow::after {
  content: '';
  display: inline-block;
  height: 0.0625rem;
  background: currentColor;
  flex: 0 0 2.625rem;
}
.hero-eyebrow::after { flex: 1; }

.hero-headline {
  font-family: var(--serif-d);
  font-variation-settings: 'opsz' 144, 'SOFT' 30, 'WONK' 0;
  font-weight: 300;
  font-size: clamp(3.75rem, 6.2vw, 9rem);
  line-height: 0.96;
  letter-spacing: -0.035em;
  color: var(--ink);
}
.hero-headline em {
  font-style: italic;
  font-weight: 400;
  font-variation-settings: 'opsz' 144, 'SOFT' 100, 'WONK' 1;
  color: var(--vermilion);
}
.hero-headline .amp {
  font-family: var(--serif-d);
  font-style: italic;
  font-weight: 200;
  color: var(--ink-light);
}

.hero-deck {
  font-family: var(--serif);
  font-size: clamp(1.375rem, 1.4vw, 1.75rem);
  line-height: 1.5;
  color: var(--ink-soft);
  max-width: 56ch;
  margin-top: clamp(1.875rem, 3vw, 3rem);
  font-style: italic;
  font-variation-settings: 'opsz' 36;
}

/* Word of the day — right column */
.wotd {
  border: 1px solid var(--rule);
  padding: 2.0625rem 2.0625rem 2.25rem;
  background: var(--paper-2);
  position: relative;
}
.wotd .label {
  font-family: var(--mono);
  font-size: 1rem;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--vermilion);
  margin-bottom: 1.3125rem;
  display: flex;
  justify-content: space-between;
}
.wotd .label .num { color: var(--ink-mute); }
.wotd .zh {
  font-family: var(--cn);
  font-size: clamp(1.6875rem, 1.6vw, 2.0625rem);
  font-weight: 500;
  color: var(--ink);
  margin-bottom: 0.5625rem;
}
.wotd .en {
  font-family: var(--serif-d);
  font-variation-settings: 'opsz' 60, 'SOFT' 60;
  font-weight: 600;
  font-size: clamp(2.625rem, 3.6vw, 4.125rem);
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--ink);
  margin-bottom: 0.5625rem;
}
.wotd .ipa {
  font-family: var(--mono);
  font-size: 1.1875rem;
  color: var(--vermilion-dk);
  margin-bottom: 1.3125rem;
}
.wotd .def {
  font-family: var(--serif);
  font-size: 1.375rem;
  line-height: 1.55;
  color: var(--ink-soft);
  border-top: 1px solid var(--ink-light);
  padding-top: 1.3125rem;
}
.wotd .ex {
  font-style: italic;
  font-size: 1.3125rem;
  margin-top: 0.9375rem;
  color: var(--ink-mute);
  border-left: 2px solid var(--vermilion);
  padding-left: 0.9375rem;
}

/* ── Section headers ───────────────────────────────────────── */
.section-header {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: end;
  gap: 2.25rem;
  padding: clamp(3.375rem, 5vw, 5.625rem) 0 1.6875rem;
  border-bottom: 2px solid var(--rule);
}
.section-num {
  font-family: var(--mono);
  font-size: 1.125rem;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--vermilion);
  font-weight: 500;
  padding-bottom: 0.5625rem;
}
.section-title {
  font-family: var(--serif-d);
  font-variation-settings: 'opsz' 60, 'SOFT' 30;
  font-weight: 500;
  font-size: clamp(2.625rem, 3vw, 3.75rem);
  letter-spacing: -0.02em;
  line-height: 1;
}
.section-meta {
  font-family: var(--mono);
  font-size: 1rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--ink-mute);
  padding-bottom: 0.75rem;
}

/* ── Categories grid ──────────────────────────────────────── */
.cats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid var(--rule);
  margin-top: 0;
}
.cat-card {
  border-right: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  padding: 2.4375rem 2.0625rem 2.0625rem;
  background: transparent;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  gap: 0.9375rem;
  text-decoration: none;
  color: inherit;
  position: relative;
  isolation: isolate;
  min-height: 20.625rem;
  transition: background 0.32s ease, transform 0.32s ease;
  overflow: hidden;
}
.cat-card:nth-child(4n) { border-right: none; }
.cat-card::after {
  content: '';
  position: absolute;
  inset: auto 0 0 0;
  height: 0;
  background: var(--vermilion);
  z-index: -1;
  transition: height 0.32s cubic-bezier(0.2, 0.8, 0.2, 1);
}
.cat-card:hover::after { height: 100%; }
.cat-card:hover { color: var(--paper); }
.cat-card:hover .cat-num,
.cat-card:hover .cat-zh,
.cat-card:hover .cat-en,
.cat-card:hover .cat-blurb,
.cat-card:hover .cat-meta { color: var(--paper); }
.cat-card:hover .cat-num::before { background: var(--paper); }

.cat-num {
  font-family: var(--mono);
  font-size: 1rem;
  letter-spacing: 0.2em;
  color: var(--vermilion);
  display: flex;
  align-items: center;
  gap: 0.9375rem;
  transition: color 0.32s ease;
}
.cat-num::before {
  content: '';
  width: 1.6875rem;
  height: 0.0625rem;
  background: var(--vermilion);
  display: inline-block;
  transition: background 0.32s ease;
}
.cat-zh {
  font-family: var(--cn);
  font-weight: 500;
  font-size: 1.6875rem;
  color: var(--ink-soft);
  transition: color 0.32s ease;
}
.cat-en {
  font-family: var(--serif-d);
  font-variation-settings: 'opsz' 48, 'SOFT' 50;
  font-weight: 500;
  font-size: 2.4375rem;
  line-height: 1.05;
  letter-spacing: -0.015em;
  color: var(--ink);
  transition: color 0.32s ease;
  margin-top: -0.1875rem;
}
.cat-blurb {
  font-family: var(--serif);
  font-style: italic;
  font-size: 1.1875rem;
  line-height: 1.45;
  color: var(--ink-mute);
  margin-top: auto;
  transition: color 0.32s ease;
}
.cat-meta {
  font-family: var(--mono);
  font-size: 0.9375rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--ink-mute);
  margin-top: 0.5625rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: color 0.32s ease;
}
.cat-meta .progress-pill {
  font-variant-numeric: tabular-nums;
  border: 1px solid currentColor;
  padding: 0.1875rem 0.625rem;
  font-size: 0.875rem;
}

/* ── Category page ────────────────────────────────────────── */
.cat-header {
  padding: clamp(3rem, 5vw, 6rem) 0 2.625rem;
  border-bottom: 1px solid var(--rule);
}
.cat-header .crumb {
  font-family: var(--mono);
  font-size: 1rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  margin-bottom: 2.25rem;
  color: var(--ink-mute);
}
.cat-header .crumb a {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid var(--ink-light);
  padding-bottom: 0.0625rem;
}
.cat-header .crumb a:hover { color: var(--vermilion); border-color: var(--vermilion); }

.cat-title-wrap {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
  gap: clamp(2.625rem, 5vw, 6rem);
  align-items: end;
}
.cat-title-num {
  font-family: var(--mono);
  font-size: 1.125rem;
  letter-spacing: 0.32em;
  color: var(--vermilion);
  margin-bottom: 1.5rem;
}
.cat-title-zh {
  font-family: var(--cn);
  font-weight: 500;
  font-size: clamp(2.0625rem, 2.2vw, 2.8125rem);
  color: var(--ink-soft);
  margin-bottom: 0.375rem;
}
.cat-title-en {
  font-family: var(--serif-d);
  font-variation-settings: 'opsz' 144, 'SOFT' 30;
  font-weight: 400;
  font-size: clamp(3.75rem, 6.5vw, 8.25rem);
  line-height: 0.95;
  letter-spacing: -0.035em;
}
.cat-blurb-big {
  font-family: var(--serif);
  font-style: italic;
  font-variation-settings: 'opsz' 24;
  font-size: clamp(1.375rem, 1.4vw, 1.75rem);
  line-height: 1.5;
  color: var(--ink-soft);
  max-width: 44ch;
  padding-bottom: 0.75rem;
}
.cat-actions {
  display: flex;
  gap: 1.3125rem;
  margin-top: 2.625rem;
  flex-wrap: wrap;
}
.btn {
  font-family: var(--mono);
  font-size: 1rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  padding: 1.3125rem 2.0625rem;
  border: 1px solid var(--ink);
  background: transparent;
  color: var(--ink);
  cursor: pointer;
  text-decoration: none;
  transition: background 0.2s ease, color 0.2s ease, transform 0.2s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.9375rem;
  font-weight: 500;
}
.btn:hover { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.btn.primary { background: var(--vermilion); border-color: var(--vermilion); color: var(--paper); }
.btn.primary:hover { background: var(--vermilion-dk); border-color: var(--vermilion-dk); color: var(--paper); }
.btn.ghost { border-color: var(--ink-light); color: var(--ink-soft); }
.btn.ghost:hover { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.btn:disabled { opacity: 0.4; cursor: not-allowed; }

/* ── Term list ────────────────────────────────────────────── */
.terms {
  border-top: 0;
}
.term {
  display: grid;
  grid-template-columns: 5.625rem minmax(0, 1.1fr) minmax(0, 1.4fr) auto;
  gap: clamp(1.5rem, 3vw, 3.375rem);
  padding: 2.4375rem 0;
  border-bottom: 1px solid var(--ink-light);
  align-items: baseline;
  position: relative;
  cursor: default;
}
.term:hover { background: rgba(185,53,27,0.04); }
.term.mastered { opacity: 0.55; }
.term.mastered .term-en { text-decoration: line-through; text-decoration-color: var(--vermilion); text-decoration-thickness: 0.0625rem; }

.term-idx {
  font-family: var(--mono);
  font-size: 1rem;
  color: var(--vermilion);
  letter-spacing: 0.18em;
  font-variant-numeric: tabular-nums;
  padding-top: 0.375rem;
}
.term-head .term-zh {
  font-family: var(--cn);
  font-weight: 500;
  font-size: 1.75rem;
  color: var(--ink-soft);
  margin-bottom: 0.375rem;
}
.term-head .term-en {
  font-family: var(--serif-d);
  font-variation-settings: 'opsz' 60, 'SOFT' 50;
  font-weight: 600;
  font-size: 2.4375rem;
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--ink);
}
.term-head .term-ipa {
  font-family: var(--mono);
  font-size: 1.125rem;
  color: var(--vermilion-dk);
  margin-top: 0.375rem;
  font-weight: 400;
}
.term-body .term-def {
  font-family: var(--serif);
  font-size: 1.5625rem;
  line-height: 1.55;
  color: var(--ink);
  font-variation-settings: 'opsz' 18;
}
.term-body .term-ex {
  font-family: var(--serif);
  font-style: italic;
  font-size: 1.3125rem;
  line-height: 1.55;
  color: var(--ink-mute);
  margin-top: 0.75rem;
  padding-left: 1.3125rem;
  border-left: 2px solid var(--vermilion);
}
.term-ex-toggle {
  display: inline;
  margin-left: 0.9375rem;
  border: 0;
  background: transparent;
  color: var(--vermilion);
  cursor: pointer;
  font-family: var(--mono);
  font-size: 1rem;
  font-style: normal;
  letter-spacing: 0.18em;
  text-decoration: underline;
  text-underline-offset: 0.1875rem;
  padding: 0;
}
.term-ex-toggle:hover { color: var(--vermilion-dk); }
.term-ex-zh {
  font-family: var(--cn);
  font-size: 1.3125rem;
  color: var(--ink-soft);
  margin-top: 0.5625rem;
  padding-left: 1.3125rem;
  border-left: 2px solid rgba(185,53,27,0.4);
  line-height: 1.55;
}
.iconbtn-inline {
  width: 2.0625rem;
  height: 2.0625rem;
  border: 0;
  background: transparent;
  color: var(--ink-mute);
  cursor: pointer;
  font-family: var(--serif-d);
  font-size: 1.375rem;
  font-style: normal;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  vertical-align: middle;
  transition: color 0.2s ease;
  padding: 0;
}
.iconbtn-inline:hover { color: var(--vermilion); }

.term-actions {
  display: flex;
  gap: 0.75rem;
  align-self: start;
  padding-top: 0.375rem;
}
.iconbtn {
  width: 3rem;
  height: 3rem;
  border: 1px solid var(--ink-light);
  background: transparent;
  color: var(--ink-soft);
  cursor: pointer;
  font-family: var(--serif-d);
  font-size: 1.5rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease;
  border-radius: 0;
  padding: 0;
}
.iconbtn:hover { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.iconbtn.active { background: var(--vermilion); color: var(--paper); border-color: var(--vermilion); }

/* ── Flashcard study mode ─────────────────────────────────── */
.study {
  padding: clamp(1.75rem, 5vw, 3.5rem) 0;
  min-height: calc(100vh - 5.625rem);
  display: flex;
  flex-direction: column;
}
.study-header {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: end;
  gap: 1.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--rule);
}
.study-header .crumb {
  font-family: var(--mono);
  font-size: 0.6875rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--ink-mute);
}
.study-header .crumb a {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid var(--ink-light);
}
.study-header .crumb a:hover { color: var(--vermilion); border-color: var(--vermilion); }
.study-header h2 {
  font-family: var(--serif-d);
  font-variation-settings: 'opsz' 60, 'SOFT' 30;
  font-weight: 500;
  font-size: clamp(1.375rem, 2.4vw, 2rem);
  letter-spacing: -0.02em;
  line-height: 1;
}
.study-progress {
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  color: var(--vermilion);
  font-variant-numeric: tabular-nums;
}

.flashcard-stage {
  flex: 1;
  display: grid;
  place-items: center;
  padding: clamp(1.5rem, 6vw, 5rem) 0;
  perspective: 125rem;
}
.flashcard {
  width: min(45rem, 95%);
  aspect-ratio: 1.45 / 1;
  position: relative;
  transform-style: preserve-3d;
  transition: transform 0.62s cubic-bezier(0.18, 0.85, 0.18, 1);
  cursor: pointer;
}
.flashcard.flipped { transform: rotateY(180deg); }
.flashcard-side {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  border: 1px solid var(--ink);
  background: var(--paper-2);
  padding: clamp(1.75rem, 5vw, 3.5rem);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  box-shadow:
    0 0.0625rem 0 rgba(26,20,20,0.08),
    0 0.5rem 1.5rem -1rem rgba(26,20,20,0.4),
    0 1.75rem 5rem -2.5rem rgba(26,20,20,0.4);
}
.flashcard-side.back {
  transform: rotateY(180deg);
  background: var(--paper);
}
.fc-meta {
  display: flex;
  justify-content: space-between;
  font-family: var(--mono);
  font-size: 0.65625rem;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--vermilion);
}
.fc-front .fc-zh {
  font-family: var(--cn);
  font-weight: 500;
  font-size: clamp(3rem, 8vw, 6rem);
  line-height: 1;
  text-align: center;
  color: var(--ink);
  letter-spacing: 0.03em;
}
.fc-hint {
  text-align: center;
  font-family: var(--serif);
  font-style: italic;
  color: var(--ink-mute);
  font-size: 0.8125rem;
}
.fc-back-en {
  font-family: var(--serif-d);
  font-variation-settings: 'opsz' 144, 'SOFT' 60;
  font-weight: 500;
  font-size: clamp(2rem, 5vw, 3.75rem);
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--ink);
}
.fc-back-ipa {
  font-family: var(--mono);
  font-size: 0.875rem;
  color: var(--vermilion-dk);
  margin-top: 0.625rem;
}
.fc-back-def {
  font-family: var(--serif);
  font-size: 1.0625rem;
  line-height: 1.55;
  margin-top: 1.125rem;
  color: var(--ink);
}
.fc-back-ex {
  font-family: var(--serif);
  font-style: italic;
  font-size: 0.90625rem;
  line-height: 1.55;
  color: var(--ink-mute);
  margin-top: 0.75rem;
  padding-left: 0.875rem;
  border-left: 2px solid var(--vermilion);
}
.fc-back-ex-zh {
  font-family: var(--cn);
  color: var(--ink-soft);
  font-size: 0.875rem;
  line-height: 1.55;
  margin-top: 0.5rem;
}

.study-controls {
  border-top: 1px solid var(--rule);
  padding-top: 1.375rem;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 1rem;
  align-items: center;
}
.study-controls .left,
.study-controls .right { display: flex; gap: 0.625rem; }
.study-controls .right { justify-content: flex-end; }

.kb-hint {
  font-family: var(--mono);
  font-size: 0.65625rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-mute);
  text-align: center;
}
.kb-hint kbd {
  font-family: var(--mono);
  font-size: 0.625rem;
  border: 1px solid var(--ink-light);
  padding: 0.125rem 0.375rem;
  background: var(--paper-2);
  margin: 0 0.1875rem;
  letter-spacing: 0;
}

/* ── Quiz mode ────────────────────────────────────────────── */
.quiz {
  padding: clamp(1.75rem, 5vw, 3.5rem) 0;
  min-height: calc(100vh - 5.625rem);
}
.quiz-stage {
  max-width: min(55rem, 92%);
  margin: clamp(2rem, 4vw, 4.5rem) auto 0;
  border: 1px solid var(--rule);
  background: var(--paper-2);
  padding: clamp(2rem, 4vw, 3.5rem);
}
.quiz-question-meta {
  font-family: var(--mono);
  font-size: 0.8125rem;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--vermilion);
  margin-bottom: 1.625rem;
  display: flex;
  justify-content: space-between;
}
.quiz-prompt-zh {
  font-family: var(--cn);
  font-size: 1.3125rem;
  color: var(--ink-soft);
  margin-bottom: 0.5rem;
}
.quiz-prompt-en {
  font-family: var(--serif-d);
  font-variation-settings: 'opsz' 60, 'SOFT' 40;
  font-weight: 500;
  font-size: clamp(2.125rem, 3.6vw, 3.25rem);
  line-height: 1.05;
  letter-spacing: -0.018em;
  color: var(--ink);
}
.quiz-prompt-ipa {
  font-family: var(--mono);
  font-size: 0.9375rem;
  color: var(--vermilion-dk);
  margin-top: 0.4375rem;
}
.quiz-question-text {
  font-family: var(--serif);
  font-style: italic;
  color: var(--ink-mute);
  margin: 1.625rem 0 1rem;
  font-size: 1rem;
}
.quiz-choices {
  display: grid;
  gap: 0.6875rem;
}
.choice {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1rem;
  padding: 0.9375rem 1.25rem;
  border: 1px solid var(--ink-light);
  background: var(--paper);
  font-family: var(--cn);
  font-size: 1.1875rem;
  text-align: left;
  cursor: pointer;
  transition: all 0.18s ease;
  align-items: center;
  color: var(--ink);
}
.choice:hover:not(:disabled) { border-color: var(--ink); transform: translateX(0.125rem); }
.choice .ix {
  font-family: var(--mono);
  font-size: 0.875rem;
  letter-spacing: 0.18em;
  color: var(--vermilion);
  width: 1.625rem;
}
.choice.correct { background: var(--moss); color: var(--paper); border-color: var(--moss); }
.choice.correct .ix { color: var(--paper); }
.choice.wrong { background: var(--vermilion); color: var(--paper); border-color: var(--vermilion); }
.choice.wrong .ix { color: var(--paper); }
.choice:disabled { cursor: default; }

.quiz-feedback {
  margin-top: 1.75rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--ink-light);
  font-family: var(--serif);
  font-size: 1rem;
  line-height: 1.55;
  color: var(--ink-soft);
  font-variation-settings: 'opsz' 18;
  display: none;
}
.quiz-feedback.show { display: block; animation: fadeIn 0.32s ease both; }
.quiz-feedback strong {
  font-family: var(--serif-d);
  font-weight: 600;
}
.quiz-ex-zh {
  margin-top: 0.375rem;
  font-family: var(--cn);
  font-size: 0.9375rem;
  color: var(--ink-soft);
  line-height: 1.55;
}
.quiz-next {
  margin-top: 1.25rem;
  display: flex;
  justify-content: flex-end;
}

.quiz-result {
  text-align: center;
  padding: clamp(2.5rem, 8vw, 5rem) 0;
}
.quiz-result .score {
  font-family: var(--serif-d);
  font-variation-settings: 'opsz' 144, 'SOFT' 0, 'WONK' 1;
  font-weight: 400;
  font-size: clamp(6rem, 18vw, 13.75rem);
  line-height: 1;
  color: var(--vermilion);
  letter-spacing: -0.05em;
}
.quiz-result .score .total { color: var(--ink-light); font-size: 0.6em; }
.quiz-result .lbl {
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  color: var(--ink-mute);
  margin-top: 0.625rem;
}
.quiz-result .verdict {
  font-family: var(--serif-d);
  font-variation-settings: 'opsz' 60, 'SOFT' 40;
  font-style: italic;
  font-weight: 400;
  font-size: clamp(1.375rem, 2.4vw, 1.875rem);
  margin: 1.5rem 0 2.25rem;
  color: var(--ink);
}
.quiz-result-actions {
  display: flex;
  gap: 0.875rem;
  justify-content: center;
  flex-wrap: wrap;
}

/* ── Vocab admin ─────────────────────────────────────────── */
.admin {
  padding: clamp(1.75rem, 5vw, 3.5rem) 0;
}
.admin-header {
  border-bottom: 1px solid var(--rule);
  padding-bottom: 1.5rem;
}
.admin-header .crumb {
  font-family: var(--mono);
  font-size: 0.6875rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--ink-mute);
  margin-bottom: 1.25rem;
}
.admin-header .crumb a {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid var(--ink-light);
}
.admin-header .crumb a:hover { color: var(--vermilion); border-color: var(--vermilion); }
.admin-title-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 1.5rem;
  align-items: end;
}
.admin h1 {
  font-family: var(--serif-d);
  font-variation-settings: 'opsz' 144, 'SOFT' 30;
  font-weight: 400;
  font-size: clamp(2.375rem, 6vw, 4.875rem);
  line-height: 0.95;
  letter-spacing: -0.035em;
}
.admin-header p {
  max-width: 62ch;
  margin-top: 0.875rem;
  font-size: 1.0625rem;
  line-height: 1.5;
  color: var(--ink-soft);
  font-style: italic;
}
.admin-toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  padding: 1.375rem 0 0.875rem;
}
.admin-stats {
  font-family: var(--mono);
  font-size: 0.6875rem;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--vermilion);
  border-top: 1px solid var(--ink-light);
  border-bottom: 1px solid var(--ink-light);
  padding: 0.75rem 0;
}
.admin-search-wrap {
  margin: 1.125rem 0;
}
.admin-search {
  width: min(32.5rem, 100%);
}
.admin-import-modal {
  border: 1px solid var(--rule);
  background: var(--paper-2);
  padding: 1rem;
  margin: 1.125rem 0 1.75rem;
}
.admin-import-modal textarea {
  width: 100%;
  min-height: 6.875rem;
  resize: vertical;
  border: 1px solid var(--ink-light);
  background: var(--paper);
  color: var(--ink);
  font-family: var(--mono);
  font-size: 0.75rem;
  line-height: 1.5;
  padding: 0.75rem;
  outline: none;
}
.admin-import-modal textarea:focus {
  border-color: var(--vermilion);
  background: var(--paper-2);
}
.admin-import-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 0.75rem;
}
.admin-import-actions p,
.admin-message {
  font-family: var(--mono);
  font-size: 0.65625rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-mute);
}
.admin-message {
  min-height: 1.125rem;
  margin-top: 0.625rem;
  color: var(--moss);
}
.admin-message.error { color: var(--vermilion); }
.admin-saved-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  border: 1px solid var(--ink-light);
  background: var(--paper-2);
  padding: 0.5rem 0.625rem;
  font-family: var(--mono);
  font-size: 0.625rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-mute);
  white-space: nowrap;
}
.admin-saved-pill .dot {
  width: 0.5rem;
  height: 0.5rem;
  border-radius: 50%;
  background: var(--moss);
  display: inline-block;
}
.admin-saved-pill.unsaved { color: var(--vermilion); border-color: var(--vermilion); }
.admin-saved-pill.unsaved .dot { background: var(--vermilion); }
.admin-cat-section {
  border-top: 1px solid var(--rule);
  margin-top: 1.375rem;
  background: rgba(236,226,199,0.42);
}
.admin-cat-section[open] {
  border-bottom: 1px solid var(--rule);
}
.admin-cat-header {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 1.125rem;
  align-items: center;
  padding: 1.125rem 0;
  cursor: pointer;
  font-family: var(--mono);
  font-size: 0.6875rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--vermilion);
}
.admin-cat-title {
  font-family: var(--serif-d);
  font-size: clamp(1.375rem, 2.5vw, 2.125rem);
  letter-spacing: -0.02em;
  line-height: 1.05;
  text-transform: none;
  color: var(--ink);
}
.admin-cat-fields {
  display: grid;
  grid-template-columns: minmax(7.5rem, 0.65fr) repeat(2, minmax(10rem, 1fr)) minmax(13.75rem, 1.4fr);
  gap: 0.75rem;
  padding-bottom: 1rem;
}
.admin-table {
  border-top: 1px solid var(--ink-light);
}
.admin-table-row {
  display: grid;
  grid-template-columns: minmax(6.875rem, 0.9fr) minmax(8.125rem, 1fr) minmax(6.25rem, 0.8fr) minmax(13.75rem, 1.55fr) minmax(13.75rem, 1.55fr) minmax(13.75rem, 1.45fr) 3.375rem;
  gap: 0.625rem;
  border-bottom: 1px solid var(--ink-light);
  padding: 0.75rem 0;
  align-items: start;
  position: relative;
}
.admin-table-row.head {
  font-family: var(--mono);
  font-size: 0.625rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--ink-mute);
  padding: 0.625rem 0;
}
.admin-cell {
  display: flex;
  flex-direction: column;
  gap: 0.375rem;
  min-width: 0;
  font-family: var(--mono);
  font-size: 0.625rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-mute);
}
.admin-cell input,
.admin-cell textarea {
  width: 100%;
  border: 1px solid var(--ink-light);
  background: var(--paper-2);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 0.9375rem;
  line-height: 1.35;
  letter-spacing: 0;
  text-transform: none;
  padding: 0.5625rem 0.625rem;
  outline: none;
}
.admin-cell textarea {
  min-height: 5.5rem;
  resize: vertical;
}
.admin-cell input:focus,
.admin-cell textarea:focus {
  border-color: var(--vermilion);
  background: var(--paper);
}
.admin-cell.actions {
  align-items: flex-end;
}
.admin-delete {
  color: var(--vermilion);
  border-color: rgba(185,53,27,0.45);
}
.admin-delete:hover {
  background: var(--vermilion);
  border-color: var(--vermilion);
}
.admin-add-term {
  margin: 1rem 0 1.125rem;
}

/* ── Footer ───────────────────────────────────────────────── */
.foot {
  border-top: 2px solid var(--rule);
  margin-top: 6rem;
  padding: 3.375rem 0 5.25rem;
  font-family: var(--mono);
  font-size: 1rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-mute);
}
.foot .container {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 2.8125rem;
  align-items: center;
}
.foot .pageno {
  font-family: var(--serif-d);
  font-variation-settings: 'opsz' 144, 'SOFT' 100, 'WONK' 1;
  font-weight: 300;
  font-style: italic;
  font-size: 3rem;
  text-transform: none;
  letter-spacing: -0.02em;
  color: var(--vermilion);
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 1.3125rem;
}
.admin-foot-link {
  font-family: var(--mono);
  font-size: 0.9375rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-mute);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  white-space: nowrap;
  display: none;
}
body.editable .admin-foot-link { display: inline-block; }
.admin-foot-link:hover { color: var(--vermilion); border-color: var(--vermilion); }
.foot .center { text-align: center; }

.admin-readonly-block {
  border: 1px solid var(--rule);
  background: var(--paper-2);
  padding: 1.5rem 1.5rem 1.75rem;
  margin-top: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  align-items: flex-start;
  font-family: var(--serif);
  font-size: 1rem;
  line-height: 1.55;
  color: var(--ink-soft);
}

/* ── Filtering / search ───────────────────────────────────── */
.cats.filtering .cat-card { transition: opacity 0.24s ease; }
.cats.filtering .cat-card.hidden { opacity: 0.18; pointer-events: none; }
.term.hidden { display: none; }
.search-summary {
  font-family: var(--mono);
  font-size: 0.6875rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--vermilion);
  margin: 0.75rem 0 0;
  padding: 0 var(--gutter);
}

/* ── View transitions ─────────────────────────────────────── */
.view {
  animation: fadeUp 0.45s cubic-bezier(0.18, 0.85, 0.18, 1) both;
}
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(0.5rem); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* Stagger in cat cards */
.cats .cat-card { animation: fadeUp 0.5s cubic-bezier(0.18, 0.85, 0.18, 1) both; }
.cats .cat-card:nth-child(1)  { animation-delay: 0.02s; }
.cats .cat-card:nth-child(2)  { animation-delay: 0.05s; }
.cats .cat-card:nth-child(3)  { animation-delay: 0.08s; }
.cats .cat-card:nth-child(4)  { animation-delay: 0.11s; }
.cats .cat-card:nth-child(5)  { animation-delay: 0.14s; }
.cats .cat-card:nth-child(6)  { animation-delay: 0.17s; }
.cats .cat-card:nth-child(7)  { animation-delay: 0.20s; }
.cats .cat-card:nth-child(8)  { animation-delay: 0.23s; }
.cats .cat-card:nth-child(9)  { animation-delay: 0.26s; }
.cats .cat-card:nth-child(10) { animation-delay: 0.29s; }
.cats .cat-card:nth-child(n+11) { animation-delay: 0.32s; }

/* Term list stagger */
.term { animation: fadeUp 0.4s ease-out both; }
.term:nth-child(1) { animation-delay: 0.02s; }
.term:nth-child(2) { animation-delay: 0.05s; }
.term:nth-child(3) { animation-delay: 0.08s; }
.term:nth-child(4) { animation-delay: 0.11s; }
.term:nth-child(5) { animation-delay: 0.14s; }
.term:nth-child(6) { animation-delay: 0.17s; }
.term:nth-child(7) { animation-delay: 0.20s; }
.term:nth-child(8) { animation-delay: 0.23s; }

/* ── Responsive ───────────────────────────────────────────── */
@media (max-width: 1080px) {
  .cats { grid-template-columns: repeat(3, 1fr); }
  .cats .cat-card:nth-child(4n) { border-right: 0.0625rem solid var(--rule); }
  .cats .cat-card:nth-child(3n) { border-right: none; }
  .hero-inner { grid-template-columns: 1fr; gap: 2.25rem; }
  .cat-title-wrap { grid-template-columns: 1fr; gap: 1.5rem; }
  .admin-cat-fields { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .admin-table-row {
    grid-template-columns: repeat(2, minmax(0, 1fr)) 2.875rem;
  }
  .admin-table-row.head { display: none; }
  .admin-cell::before {
    content: attr(data-label);
    font-family: var(--mono);
    font-size: 0.625rem;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--ink-mute);
  }
  .admin-cell.actions::before { content: ''; }
}
@media (max-width: 760px) {
  :root { --gutter: 1.125rem; }
  .topbar .container {
    grid-template-columns: 1fr auto;
    grid-template-areas:
      "brand meta"
      "search search";
    gap: 0.75rem 0.875rem;
    align-items: center;
  }
  .topbar .brand { grid-area: brand; justify-self: start; }
  .topbar .meta { grid-area: meta; justify-self: end; align-self: center; text-align: right; }
  .topbar .search-wrap { grid-area: search; justify-self: stretch; width: 100%; }
  .search { width: 100%; }

  .hero { padding: 2.25rem 0 1.75rem; }
  .hero-inner { gap: 1.5rem; }
  .hero-eyebrow { font-size: 0.625rem; gap: 0.75rem; margin-bottom: 0.875rem; }
  .hero-eyebrow::before, .hero-eyebrow::after { flex: 0 0 1.25rem; }
  .hero-headline {
    font-size: clamp(2.375rem, 9vw, 3.5rem);
    line-height: 1.02;
    word-break: break-word;
    overflow-wrap: anywhere;
  }
  .hero-deck { font-size: 0.875rem; margin-top: 1.125rem; }

  .wotd { padding: 1.125rem 1rem 1.25rem; }
  .wotd .label { font-size: 0.625rem; margin-bottom: 0.75rem; }
  .wotd .zh { font-size: 1rem; margin-bottom: 0.25rem; }
  .wotd .en {
    font-size: clamp(1.625rem, 6.5vw, 2.25rem);
    line-height: 1.1;
    word-break: break-word;
    overflow-wrap: anywhere;
  }
  .wotd .ipa { font-size: 0.75rem; margin-bottom: 0.75rem; }
  .wotd .def { font-size: 0.875rem; padding-top: 0.75rem; }
  .wotd .ex { font-size: 0.8125rem; margin-top: 0.5rem; padding-left: 0.625rem; }

  .section-header { gap: 1rem; padding: 2rem 0 0.875rem; }
  .section-num { font-size: 0.6875rem; padding-bottom: 0.25rem; }
  .section-title { font-size: clamp(1.5rem, 6vw, 2rem); }
  .section-meta { font-size: 0.625rem; padding-bottom: 0.375rem; }

  .cats { grid-template-columns: repeat(2, 1fr); }
  .cats .cat-card:nth-child(3n) { border-right: 0.0625rem solid var(--rule); }
  .cats .cat-card:nth-child(2n) { border-right: none; }
  .cat-card {
    padding: 1rem 0.875rem 0.875rem;
    gap: 0.4375rem;
    min-height: 10.5rem;
  }
  .cat-num { font-size: 0.59375rem; gap: 0.4375rem; letter-spacing: 0.16em; }
  .cat-num::before { width: 0.75rem; }
  .cat-zh { font-size: 0.875rem; }
  .cat-en {
    font-size: 1.0625rem;
    line-height: 1.1;
    letter-spacing: -0.005em;
    word-break: break-word;
    overflow-wrap: anywhere;
    hyphens: auto;
  }
  .cat-blurb { font-size: 0.6875rem; line-height: 1.4; }
  .cat-meta { font-size: 0.5625rem; margin-top: 0.3125rem; letter-spacing: 0.16em; }
  .cat-meta .progress-pill { padding: 0.0625rem 0.3125rem; font-size: 0.53125rem; }

  .term { padding: 1.25rem 0; gap: 0.875rem; }
  .term-idx { font-size: 0.6875rem; padding-top: 0.1875rem; }
  .term-head .term-zh { font-size: 1rem; margin-bottom: 0.1875rem; }
  .term-head .term-en {
    font-size: 1.375rem;
    line-height: 1.12;
    word-break: break-word;
    overflow-wrap: anywhere;
  }
  .term-head .term-ipa { font-size: 0.75rem; margin-top: 0.1875rem; }
  .term-body .term-def { font-size: 0.9375rem; }
  .term-body .term-ex { font-size: 0.8125rem; margin-top: 0.5rem; padding-left: 0.75rem; }
  .term-ex-zh { font-size: 0.8125rem; padding-left: 0.75rem; }
  .iconbtn { width: 2.125rem; height: 2.125rem; font-size: 1rem; }

  .cat-header { padding: 1.75rem 0 1.375rem; }
  .cat-header .crumb { font-size: 0.6875rem; margin-bottom: 1.125rem; }
  .cat-title-num { font-size: 0.6875rem; margin-bottom: 0.625rem; }
  .cat-title-zh { font-size: 1.25rem; }
  .cat-title-en {
    font-size: clamp(2.125rem, 8vw, 3.25rem);
    line-height: 1.0;
    word-break: break-word;
    overflow-wrap: anywhere;
  }
  .cat-blurb-big { font-size: 0.875rem; }
  .cat-actions { gap: 0.625rem; margin-top: 1.125rem; }
  .btn { font-size: 0.6875rem; padding: 0.75rem 1rem; gap: 0.5rem; }

  .foot { margin-top: 3rem; padding: 1.75rem 0 2.25rem; font-size: 0.6875rem; }
  .foot .container { gap: 0.875rem; }
  .foot .pageno { font-size: 1.5rem; gap: 0.625rem; }
  .admin-foot-link { font-size: 0.625rem; }
  .term {
    grid-template-columns: 2.25rem 1fr auto;
    grid-template-areas:
      "idx head action"
      ".   body body";
  }
  .term-idx  { grid-area: idx; }
  .term-head { grid-area: head; }
  .term-body { grid-area: body; }
  .term-actions { grid-area: action; }
  .foot .container { grid-template-columns: 1fr; gap: 0.875rem; text-align: center; }
  .admin-title-row { grid-template-columns: 1fr; align-items: start; }
  .admin-import-actions { align-items: stretch; flex-direction: column; }
  .admin-cat-fields { grid-template-columns: 1fr; }
  .admin-table-row {
    grid-template-columns: 1fr;
    gap: 0.625rem;
    padding: 1rem 3rem 1rem 0;
  }
  .admin-cell textarea { width: 100%; }
  .admin-cell.actions {
    position: absolute;
    top: 1rem;
    right: 0;
  }
  .foot .pageno { justify-content: center; }
}
@media (max-width: 480px) {
  :root { --gutter: 0.875rem; }
  .cats { grid-template-columns: 1fr; }
  .cats .cat-card { border-right: none; }
  .cat-card {
    padding: 1rem 0.875rem 0.875rem;
    gap: 0.4375rem;
    min-height: 0;
  }
  .cat-num { font-size: 0.625rem; gap: 0.5rem; letter-spacing: 0.18em; }
  .cat-num::before { width: 0.875rem; }
  .cat-zh { font-size: 0.875rem; }
  .cat-en {
    font-size: 1.1875rem;
    line-height: 1.15;
    letter-spacing: -0.01em;
  }
  .cat-blurb { font-size: 0.75rem; line-height: 1.45; }
  .cat-meta { font-size: 0.59375rem; letter-spacing: 0.18em; margin-top: 0.375rem; }
  .cat-meta .progress-pill { padding: 0.125rem 0.375rem; font-size: 0.5625rem; }

  .hero-headline { font-size: clamp(2.125rem, 10vw, 3rem); }
  .wotd .en { font-size: clamp(1.5rem, 8vw, 2rem); }
  .term-head .term-en { font-size: 1.25rem; }
  .cat-title-en { font-size: clamp(1.875rem, 9vw, 2.75rem); }
}

.lang-btn {
  appearance: none;
  -webkit-appearance: none;
  box-sizing: border-box;
  display: inline-block;
  font-family: var(--mono, monospace);
  font-size: 0.78125rem;
  letter-spacing: 0.18em;
  padding: 0.1875rem 0;
  border: 1.5px solid var(--ink);
  background: transparent;
  color: var(--ink);
  cursor: pointer;
  text-transform: uppercase;
  vertical-align: baseline;
  line-height: 1.4;
  margin: 0;
  transition: background 0.18s ease, color 0.18s ease, border-color 0.18s ease;
  white-space: nowrap;
  outline: 0;
  width: 3.5rem;
  text-align: center;
  position: relative;
}
.lang-btn + .lang-btn { margin-left: -1.5px; }
.lang-btn:hover { background: var(--paper-2); }
.lang-btn.active {
  background: var(--vermilion);
  border-color: var(--vermilion-dk);
  color: var(--paper);
  z-index: 1;
}
.topbar .meta .lang-btn { font-weight: 600; }