/* Koe Lab — one small design system, shared by the research page and the lab.
   Palette: paper / ink / a persimmon accent, with a cool secondary for data.
   No webfonts: CJK webfonts cost megabytes and the system stacks are excellent. */

:root {
  color-scheme: light dark;

  --paper: #faf7f2;
  --paper-2: #f2ede4;
  --paper-3: #e8e1d5;
  --card: #fffdfa;
  --ink: #191612;
  --ink-2: #4a443c;
  --ink-3: #7d7568;
  --rule: #ddd5c7;
  --accent: #c1502a;
  --accent-soft: #f6e3da;
  --cool: #3f6f80;
  --cool-soft: #dcebef;
  --good: #4a7d52;
  --warn: #a5732a;

  --serif: ui-serif, "Iowan Old Style", Georgia, "Yu Mincho", "Hiragino Mincho ProN",
    "Songti TC", "PMingLiU", serif;
  --sans: system-ui, -apple-system, "Segoe UI", "Hiragino Sans", "Yu Gothic UI",
    "Noto Sans CJK JP", "Microsoft JhengHei", sans-serif;
  --mono: ui-monospace, "SFMono-Regular", "Cascadia Mono", Menlo, Consolas, monospace;

  --shadow: 0 1px 2px rgba(25, 22, 18, .05), 0 8px 24px -12px rgba(25, 22, 18, .18);
  --radius: 12px;
  --measure: 34rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #14120f;
    --paper-2: #1c1915;
    --paper-3: #26221c;
    --card: #1a1713;
    --ink: #f3ede2;
    --ink-2: #c3bbac;
    --ink-3: #8d8477;
    --rule: #322c24;
    --accent: #e5814f;
    --accent-soft: #3a251a;
    --cool: #7fb3c4;
    --cool-soft: #1c2a30;
    --good: #7fb389;
    --warn: #d6a75c;
    --shadow: 0 1px 2px rgba(0, 0, 0, .4), 0 10px 30px -14px rgba(0, 0, 0, .7);
  }
}

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.72;
  font-feature-settings: "palt" 1;
  text-rendering: optimizeLegibility;
}

a { color: inherit; text-decoration-color: var(--accent); text-underline-offset: 3px; }
a:hover { color: var(--accent); }

h1, h2, h3, h4 { font-family: var(--serif); font-weight: 600; line-height: 1.28; margin: 0; }
h1 { font-size: clamp(2.1rem, 5.2vw, 3.4rem); letter-spacing: -.015em; }
h2 { font-size: clamp(1.45rem, 3vw, 1.95rem); letter-spacing: -.01em; }
h3 { font-size: 1.12rem; }
p { margin: 0 0 1.05em; }
small { font-size: .82rem; }
code, kbd { font-family: var(--mono); font-size: .86em; }
code { background: var(--paper-2); padding: .1em .38em; border-radius: 5px; }
kbd {
  background: var(--card); border: 1px solid var(--rule); border-bottom-width: 2px;
  border-radius: 5px; padding: .05em .4em; font-size: .78em; color: var(--ink-2);
}

.wrap { width: min(100% - 2.5rem, 68rem); margin-inline: auto; }
.narrow { max-width: var(--measure); }
.stack > * + * { margin-top: var(--gap, 1rem); }
.muted { color: var(--ink-3); }
.mono-num { font-variant-numeric: tabular-nums; }

/* ---------------------------------------------------------------- chrome */

.topbar {
  position: sticky; top: 0; z-index: 40;
  backdrop-filter: saturate(1.4) blur(12px);
  background: color-mix(in srgb, var(--paper) 86%, transparent);
  border-bottom: 1px solid var(--rule);
}
.topbar__inner {
  display: flex; align-items: center; gap: 1.1rem;
  min-height: 3.4rem;
}
.brand {
  display: inline-flex; align-items: baseline; gap: .5rem;
  font-family: var(--serif); font-size: 1.06rem; font-weight: 600;
  text-decoration: none; letter-spacing: -.01em;
}
.brand .jp { color: var(--accent); font-size: .95em; }
.topnav { margin-left: auto; display: flex; gap: .3rem; flex-wrap: wrap; }
.topnav a {
  text-decoration: none; font-size: .88rem; color: var(--ink-2);
  padding: .3rem .7rem; border-radius: 99px;
}
.topnav a:hover { background: var(--paper-2); color: var(--ink); }
.topnav a[aria-current="page"] { background: var(--accent-soft); color: var(--accent); }

.footer {
  margin-top: 5rem; border-top: 1px solid var(--rule);
  padding: 2.4rem 0 3.4rem; color: var(--ink-3); font-size: .86rem;
}
.footer a { text-decoration-color: var(--rule); }

/* ---------------------------------------------------------------- pieces */

.pill {
  display: inline-flex; align-items: center; gap: .35rem;
  font-size: .74rem; letter-spacing: .04em; text-transform: uppercase;
  padding: .18rem .6rem; border-radius: 99px;
  background: var(--paper-2); color: var(--ink-3); border: 1px solid var(--rule);
  white-space: nowrap;
}
.pill--accent { background: var(--accent-soft); color: var(--accent); border-color: transparent; }
.pill--cool { background: var(--cool-soft); color: var(--cool); border-color: transparent; }

.card {
  background: var(--card); border: 1px solid var(--rule);
  border-radius: var(--radius); padding: 1.15rem 1.25rem;
}

.btn {
  font: inherit; font-size: .9rem; cursor: pointer;
  display: inline-flex; align-items: center; justify-content: center; gap: .45rem;
  padding: .48rem .95rem; border-radius: 9px;
  border: 1px solid var(--rule); background: var(--card); color: var(--ink);
  transition: background .12s, border-color .12s, transform .06s;
}
.btn:hover { background: var(--paper-2); }
.btn:active { transform: translateY(1px); }
.btn[aria-pressed="true"], .btn--on { background: var(--accent-soft); border-color: transparent; color: var(--accent); }
.btn--primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn--primary:hover { background: color-mix(in srgb, var(--accent) 86%, #000); }
.btn--ghost { border-color: transparent; background: transparent; color: var(--ink-3); }
.btn--ghost:hover { background: var(--paper-2); color: var(--ink); }
.btn:disabled { opacity: .42; cursor: not-allowed; }

.seg { display: inline-flex; background: var(--paper-2); border: 1px solid var(--rule); border-radius: 10px; padding: 2px; gap: 2px; }
.seg button {
  font: inherit; font-size: .86rem; cursor: pointer; border: 0; background: transparent;
  color: var(--ink-3); padding: .34rem .8rem; border-radius: 8px; white-space: nowrap;
}
.seg button[aria-selected="true"] { background: var(--card); color: var(--ink); box-shadow: var(--shadow); }

table { width: 100%; border-collapse: collapse; font-size: .9rem; }
th, td { text-align: left; padding: .55rem .7rem; border-bottom: 1px solid var(--rule); vertical-align: top; }
th { font-size: .76rem; letter-spacing: .05em; text-transform: uppercase; color: var(--ink-3); font-weight: 600; }
tbody tr:hover { background: var(--paper-2); }
.scroll-x { overflow-x: auto; -webkit-overflow-scrolling: touch; }

hr { border: 0; border-top: 1px solid var(--rule); margin: 2.6rem 0; }

/* ------------------------------------------------------------- research */

.hero { padding: clamp(3rem, 9vw, 6rem) 0 2.5rem; }
.hero__kicker { font-size: .82rem; letter-spacing: .12em; text-transform: uppercase; color: var(--accent); margin-bottom: 1rem; }
.hero__lede { font-size: clamp(1.02rem, 2.2vw, 1.2rem); color: var(--ink-2); max-width: 40rem; }
.hero__actions { display: flex; flex-wrap: wrap; gap: .6rem; margin-top: 1.8rem; }

.figures { display: grid; gap: 1px; background: var(--rule); border: 1px solid var(--rule);
  border-radius: var(--radius); overflow: hidden; grid-template-columns: repeat(auto-fit, minmax(9.5rem, 1fr)); margin: 2.5rem 0; }
.figure { background: var(--card); padding: 1.05rem 1.1rem; }
.figure__n { font-family: var(--serif); font-size: 1.85rem; line-height: 1.1; font-variant-numeric: tabular-nums; }
.figure__l { font-size: .8rem; color: var(--ink-3); margin-top: .2rem; }

.section { padding: 2.6rem 0; scroll-margin-top: 4.5rem; }
.section > h2 { margin-bottom: .3rem; }
.section__sub { color: var(--ink-3); font-size: .9rem; margin-bottom: 1.6rem; }
.prose { max-width: 44rem; }
.prose ul { padding-left: 1.15rem; margin: 0 0 1.05em; }
.prose li { margin-bottom: .35em; }
.prose li::marker { color: var(--accent); }

.callout {
  border-left: 3px solid var(--accent); background: var(--paper-2);
  padding: .95rem 1.15rem; border-radius: 0 var(--radius) var(--radius) 0; margin: 1.4rem 0;
}
.callout--cool { border-left-color: var(--cool); }
.callout p:last-child { margin-bottom: 0; }
.callout__t { font-weight: 650; margin-bottom: .25rem; display: block; }

.toc {
  position: sticky; top: 4.4rem; align-self: start; font-size: .86rem;
  border-left: 1px solid var(--rule); padding-left: 1rem;
}
.toc a { display: block; padding: .22rem 0; text-decoration: none; color: var(--ink-3); }
.toc a:hover, .toc a.is-active { color: var(--accent); }
.layout-toc { display: grid; gap: 3rem; grid-template-columns: minmax(0, 1fr); }
@media (min-width: 62rem) { .layout-toc { grid-template-columns: minmax(0, 1fr) 12rem; } }

/* ------------------------------------------------------------------ lab */

.lab { padding-bottom: 4rem; }
.lab__bar {
  display: flex; flex-wrap: wrap; gap: .6rem; align-items: center;
  padding: .85rem 0; border-bottom: 1px solid var(--rule); margin-bottom: 1.4rem;
}
.lab__bar .spacer { flex: 1 1 auto; }

.panel { display: none; }
.panel.is-active { display: block; }

.line-card { border: 1px solid var(--rule); background: var(--card); border-radius: var(--radius); padding: 1.15rem 1.25rem; }
.line-jp { font-size: clamp(1.3rem, 3.4vw, 1.85rem); font-family: var(--serif); line-height: 1.62; letter-spacing: .01em; }
.line-jp .ch { transition: color .08s, background-color .08s; border-radius: 3px; }
.line-jp .ch.is-on { color: var(--accent); background: var(--accent-soft); }
.line-jp .ch.is-done { color: var(--ink-2); }
.line-sub { font-size: .92rem; color: var(--ink-2); margin-top: .55rem; }
.line-romaji { font-size: .86rem; color: var(--ink-3); font-style: italic; }
.line-gloss { font-size: .95rem; margin-top: .35rem; }
.line-tip { font-size: .86rem; color: var(--ink-2); background: var(--paper-2); border-radius: 9px; padding: .6rem .8rem; margin-top: .8rem; }

.voice-chips { display: flex; flex-wrap: wrap; gap: .4rem; margin-top: 1rem; }
.chip {
  font: inherit; font-size: .84rem; cursor: pointer; border-radius: 99px;
  border: 1px solid var(--rule); background: var(--card); color: var(--ink-2);
  padding: .26rem .72rem; display: inline-flex; align-items: center; gap: .35rem;
}
.chip:hover { border-color: var(--accent); color: var(--ink); }
.chip.is-playing { background: var(--accent); border-color: var(--accent); color: #fff; }
.chip .star { color: var(--warn); font-size: .78em; }
.chip .dot { width: .42rem; height: .42rem; border-radius: 99px; background: var(--cool); opacity: .55; }
.chip[data-gender="male"] .dot { background: var(--cool); }
.chip[data-gender="female"] .dot { background: var(--accent); }
.chip[data-gender="neutral"] .dot { background: var(--good); }

.rate-row { display: flex; gap: .4rem; flex-wrap: wrap; align-items: center; margin-top: 1rem; }
.star-btn {
  font: inherit; cursor: pointer; border: 1px solid var(--rule); background: var(--card);
  border-radius: 9px; width: 2.6rem; height: 2.4rem; font-size: 1rem; color: var(--ink-2);
}
.star-btn:hover { border-color: var(--warn); color: var(--warn); }
.star-btn.is-on { background: var(--warn); border-color: var(--warn); color: #fff; }

.duel { display: grid; gap: 1rem; grid-template-columns: 1fr; margin-top: 1.2rem; }
@media (min-width: 44rem) { .duel { grid-template-columns: 1fr 1fr; } }
.duel__side {
  border: 1px solid var(--rule); background: var(--card); border-radius: var(--radius);
  padding: 1.4rem 1.2rem; text-align: center; cursor: pointer; transition: border-color .12s, background .12s;
}
.duel__side:hover { border-color: var(--accent); background: var(--paper-2); }
.duel__side.is-playing { border-color: var(--accent); box-shadow: inset 0 0 0 1px var(--accent); }
.duel__label { font-family: var(--serif); font-size: 2rem; color: var(--ink-3); }
.duel__hint { font-size: .82rem; color: var(--ink-3); margin-top: .3rem; }

.meter { height: .42rem; border-radius: 99px; background: var(--paper-3); overflow: hidden; min-width: 4rem; }
.meter > i { display: block; height: 100%; background: var(--accent); border-radius: 99px; }
.meter--cool > i { background: var(--cool); }

.rank-name { font-weight: 600; display: flex; align-items: center; gap: .45rem; }
.rank-note { color: var(--ink-3); font-size: .84rem; max-width: 26rem; }
.rank-pos { font-family: var(--serif); font-size: 1.05rem; color: var(--ink-3); font-variant-numeric: tabular-nums; }
.rank-pos.top { color: var(--accent); }

.empty { text-align: center; color: var(--ink-3); padding: 3rem 1rem; border: 1px dashed var(--rule); border-radius: var(--radius); }

.keyhint { font-size: .8rem; color: var(--ink-3); display: flex; flex-wrap: wrap; gap: .8rem; margin-top: 1rem; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition-duration: .01ms !important; animation-duration: .01ms !important; }
}