:root {
  --bg: #ffffff;
  --panel: #f6f7f9;
  --ink: #16181d;
  --muted: #63676f;
  --line: #e2e5ea;
  --accent: #2f6bff;
  --accent-soft: #eaf0ff;
  --warn: #8a5a00;
  --warn-bg: #fff7e6;
  --radius: 14px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1115;
    --panel: #171a21;
    --ink: #e8eaee;
    --muted: #9aa0aa;
    --line: #262b34;
    --accent: #7aa2ff;
    --accent-soft: #1b2440;
    --warn: #ffcf7a;
    --warn-bg: #2a2213;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.55 ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
h1, h2, h3 { line-height: 1.25; }
code, textarea, .output, .cards { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; }

/* ---------- header ---------- */
.top {
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  flex-wrap: wrap;
  padding: 20px clamp(16px, 4vw, 40px);
  border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 14px; }
.logo {
  width: 42px; height: 42px; flex: none;
  display: grid; place-items: center;
  border-radius: 12px;
  background: var(--accent); color: #fff;
  font-weight: 700; font-size: 22px;
}
.top h1 { margin: 0; font-size: 1.15rem; }
.top p { margin: 2px 0 0; color: var(--muted); font-size: .875rem; }
.repo {
  color: var(--accent); text-decoration: none; font-size: .9rem; font-weight: 600;
  white-space: nowrap;
}
.repo:hover { text-decoration: underline; }

main { max-width: 1060px; margin: 0 auto; padding: clamp(16px, 3vw, 28px); }

/* ---------- language bar ---------- */
.langbar {
  display: flex; align-items: center; gap: 8px; margin-bottom: 10px;
}
.lang {
  flex: 1; padding: 10px 14px; min-width: 0;
  border: 1px solid var(--line); border-radius: 999px;
  background: var(--panel); color: var(--ink);
  font: inherit; font-weight: 600; font-size: .95rem;
  cursor: default;
}
.swap {
  flex: none; width: 42px; height: 42px;
  border: 1px solid var(--line); border-radius: 50%;
  background: var(--bg); color: var(--accent);
  font-size: 18px; cursor: pointer;
  transition: transform .18s ease, background .18s ease;
}
.swap:hover { background: var(--accent-soft); }
.swap:active { transform: rotate(180deg); }

/* ---------- panes ---------- */
.panes { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
@media (max-width: 720px) { .panes { grid-template-columns: 1fr; } }

.pane {
  display: flex; flex-direction: column;
  border: 1px solid var(--line); border-radius: var(--radius);
  background: var(--panel);
  overflow: hidden;
}
.pane.out { background: var(--bg); }
textarea, .output {
  flex: 1; min-height: 190px;
  padding: 18px; border: 0; margin: 0;
  background: transparent; color: var(--ink);
  font-size: 1.05rem; line-height: 1.6;
  resize: vertical; outline: none;
  white-space: pre-wrap; word-break: break-word;
}
.output:empty::before { content: "Translation"; color: var(--muted); }
.paneFoot {
  display: flex; align-items: center; justify-content: space-between; gap: 10px;
  padding: 8px 14px; border-top: 1px solid var(--line);
  color: var(--muted); font-size: .8rem; min-height: 38px;
}
.ghost {
  border: 1px solid var(--line); border-radius: 8px;
  background: transparent; color: var(--ink);
  padding: 4px 12px; font: inherit; font-size: .8rem; cursor: pointer;
}
.ghost:hover { background: var(--accent-soft); border-color: var(--accent); }

/* ---------- translation options ---------- */
.translationOptions {
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  flex-wrap: wrap; margin-top: 10px; color: var(--muted); font-size: .8rem;
}
.translationOptions label {
  display: inline-flex; align-items: center; gap: 8px; color: var(--ink);
  font-weight: 600; cursor: pointer;
}
.translationOptions input { accent-color: var(--accent); }

/* ---------- notes ---------- */
.notes {
  margin-top: 12px; padding: 12px 16px;
  border: 1px solid color-mix(in srgb, var(--warn) 35%, transparent);
  border-radius: var(--radius);
  background: var(--warn-bg); color: var(--warn);
  font-size: .875rem;
}
.notes ul { margin: 0; padding-left: 20px; }
.notes li + li { margin-top: 5px; }

/* ---------- unknown-term resolver ---------- */
.unknownResolver {
  margin-top: 12px; padding: 14px 16px;
  border: 1px solid var(--line); border-radius: var(--radius);
  background: var(--panel);
}
.unknownResolver h2 { margin: 0; font-size: .95rem; }
.unknownResolver p { margin: 2px 0 12px; color: var(--muted); font-size: .8rem; }
.unknownItems { display: grid; gap: 8px; }
.unknownItem {
  display: grid; grid-template-columns: minmax(100px, .7fr) minmax(180px, 1.5fr) auto;
  align-items: center; gap: 8px;
}
.unknownItem code { overflow-wrap: anywhere; }
.unknownItem input {
  min-width: 0; width: 100%; padding: 7px 10px;
  border: 1px solid var(--line); border-radius: 8px;
  background: var(--bg); color: var(--ink); font: inherit; font-size: .82rem;
}
.unknownItem input:focus { outline: 2px solid var(--accent-soft); border-color: var(--accent); }
.unknownItem button {
  border: 1px solid var(--line); border-radius: 8px;
  background: var(--bg); color: var(--ink); padding: 7px 11px;
  font: inherit; font-size: .8rem; cursor: pointer;
}
.unknownItem button:hover { border-color: var(--accent); color: var(--accent); }
.unknownItem .invalid { border-color: var(--warn); }
@media (max-width: 600px) {
  .unknownItem { grid-template-columns: 1fr auto; }
  .unknownItem code { grid-column: 1 / -1; }
}

/* ---------- examples ---------- */
.examples {
  display: flex; align-items: center; gap: 8px; flex-wrap: wrap;
  margin-top: 16px;
}
.examples .label { color: var(--muted); font-size: .85rem; }
.examples button {
  border: 1px solid var(--line); border-radius: 999px;
  background: var(--panel); color: var(--ink);
  padding: 6px 13px; font: inherit; font-size: .82rem; cursor: pointer;
}
.examples button:hover { border-color: var(--accent); color: var(--accent); }

/* ---------- breakdown ---------- */
.breakdown { margin-top: 34px; }
.breakdown h2, .explain h2 { font-size: 1.05rem; margin: 0 0 6px; }
.hint, .small { color: var(--muted); font-size: .875rem; margin: 0 0 14px; }
.cards { display: flex; flex-wrap: wrap; gap: 10px; }
.card {
  flex: 1 1 168px; min-width: 0;
  border: 1px solid var(--line); border-radius: 12px;
  background: var(--panel); padding: 12px 14px;
}
.card .w { font-size: 1.1rem; font-weight: 700; letter-spacing: .3px; }
.card .g { font-size: .85rem; margin-top: 3px; font-family: ui-sans-serif, system-ui, sans-serif; }
.card .d {
  font-size: .74rem; color: var(--muted); margin-top: 7px;
  font-family: ui-sans-serif, system-ui, sans-serif;
}
.card .tag {
  display: inline-block; margin-top: 8px; padding: 1px 8px;
  border-radius: 999px; background: var(--accent-soft); color: var(--accent);
  font-size: .68rem; font-weight: 700; letter-spacing: .5px; text-transform: uppercase;
  font-family: ui-sans-serif, system-ui, sans-serif;
}

/* ---------- explainer ---------- */
.explain { margin-top: 40px; border-top: 1px solid var(--line); padding-top: 26px; }
.cols { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; }
@media (max-width: 720px) { .cols { grid-template-columns: 1fr; } }
.explain h3 { font-size: .95rem; margin: 0 0 6px; }
.explain p { margin: 0 0 10px; font-size: .9rem; color: var(--muted); }
.explain table { border-collapse: collapse; font-size: .875rem; }
.explain td { padding: 3px 14px 3px 0; }
.explain code {
  background: var(--panel); border: 1px solid var(--line);
  border-radius: 6px; padding: 1px 7px; font-size: .85rem;
}

footer {
  max-width: 1060px; margin: 0 auto; padding: 30px clamp(16px, 3vw, 28px) 60px;
  color: var(--muted); font-size: .85rem;
}
footer a { color: var(--accent); }

/* ---------- tabs + learn mode ---------- */
.tabs { display: flex; gap: 8px; margin-bottom: 18px; }
.tab {
  padding: 8px 18px; border: 1px solid var(--line); background: var(--panel);
  color: var(--muted); border-radius: 999px; font-size: .95rem; font-weight: 600;
  cursor: pointer;
}
.tab.active { background: var(--accent); color: #fff; border-color: var(--accent); }

.learnIntro h2 { margin: 0 0 6px; }
.learnIntro p { margin: 0 0 8px; color: var(--muted); }
.learnHead { margin: 28px 0 4px; }

.domainGrid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 10px;
}
.domainTile {
  display: flex; align-items: center; gap: 10px; text-align: left;
  padding: 12px 14px; border: 1px solid var(--line); background: var(--panel);
  border-radius: var(--radius); cursor: pointer; color: var(--ink);
}
.domainTile:hover { border-color: var(--accent); }
.domainTile.active { border-color: var(--accent); background: var(--accent-soft); }
.dLetter {
  font-family: ui-monospace, Menlo, monospace; font-weight: 700; font-size: 1.25rem;
  width: 30px; height: 30px; flex: none; display: grid; place-items: center;
  background: var(--accent); color: #fff; border-radius: 8px;
}
.dLetter.big { width: 36px; height: 36px; font-size: 1.4rem; }
.dName { font-size: .9rem; }

.domainDetail {
  margin-top: 14px; padding: 16px 18px;
  border: 1px solid var(--line); border-radius: var(--radius); background: var(--panel);
}
.domainDetail h4 { margin: 0 0 12px; display: flex; align-items: center; gap: 10px; }
.subRow {
  display: grid; grid-template-columns: 70px 130px 1fr; gap: 10px; align-items: baseline;
  padding: 7px 0; border-top: 1px solid var(--line);
}
.subVowel { font-family: ui-monospace, Menlo, monospace; color: var(--accent); font-weight: 600; }
.subName { color: var(--muted); font-size: .88rem; }
.subRoots code {
  display: inline-block; margin: 0 6px 4px 0; padding: 1px 6px;
  background: var(--bg); border: 1px solid var(--line); border-radius: 6px; font-size: .85rem;
}

.drillCard, .familyDemo {
  margin-top: 8px; padding: 18px; border: 1px solid var(--line);
  border-radius: var(--radius); background: var(--panel);
}
.drillWord {
  font-family: ui-monospace, Menlo, monospace; font-size: 2.6rem; font-weight: 700;
  text-align: center; letter-spacing: 2px; margin-bottom: 14px;
}
.drillChoices { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.choice {
  padding: 10px 12px; border: 1px solid var(--line); background: var(--bg);
  border-radius: 10px; cursor: pointer; color: var(--ink); font-size: .92rem; text-align: left;
}
.choice:hover:not(:disabled) { border-color: var(--accent); }
.choice.right { background: #1f9d5522; border-color: #1f9d55; color: var(--ink); }
.choice.wrong { background: #d33a3a22; border-color: #d33a3a; }
.drillReveal { margin-top: 14px; text-align: center; font-size: 1.05rem; }
.drillReveal .muted { color: var(--muted); }
.drillFoot { display: flex; justify-content: space-between; align-items: center; margin-top: 14px; }
.drillScore { color: var(--muted); font-size: .9rem; }

.familyLesson p { color: var(--muted); }
.famHead { margin: 0 0 12px; color: var(--ink) !important; }
.famRow { display: flex; flex-wrap: wrap; gap: 10px; }
.famWord {
  display: flex; flex-direction: column; min-width: 78px;
  padding: 8px 10px; background: var(--bg); border: 1px solid var(--line); border-radius: 8px;
}
.famWord b { font-family: ui-monospace, Menlo, monospace; font-size: 1.05rem; }
.famWord span { color: var(--muted); font-size: .8rem; }
#familyNext { margin-top: 14px; }

@media (max-width: 560px) {
  .subRow { grid-template-columns: 56px 1fr; }
  .subRow .subRoots { grid-column: 1 / -1; }
  .drillChoices { grid-template-columns: 1fr; }
}