/* ============================================================
   Hangul study — styles
   ============================================================ */

:root {
  --bg: #f6f7fb;
  --surface: #ffffff;
  --surface-2: #eef0f7;
  --text: #1c1e26;
  --muted: #6b7180;
  --border: #e2e5ee;
  --accent: #3b5bdb;
  --accent-soft: #e7ecfd;
  --good: #2b8a3e;
  --good-soft: #e6f4ea;
  --bad: #c92a2a;
  --bad-soft: #fcebec;
  --shadow: 0 1px 3px rgba(20, 22, 40, .06), 0 6px 20px rgba(20, 22, 40, .05);
  --radius: 14px;
  --font: "Noto Sans KR", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #14151a;
    --surface: #1e2027;
    --surface-2: #262933;
    --text: #e8eaf0;
    --muted: #9aa0ad;
    --border: #2e313b;
    --accent: #748ffc;
    --accent-soft: #28304a;
    --good: #51cf66;
    --good-soft: #1c3025;
    --bad: #ff8787;
    --bad-soft: #3a2326;
    --shadow: 0 1px 3px rgba(0, 0, 0, .3), 0 6px 20px rgba(0, 0, 0, .35);
  }
}
:root[data-theme="dark"] {
  --bg: #14151a;
  --surface: #1e2027;
  --surface-2: #262933;
  --text: #e8eaf0;
  --muted: #9aa0ad;
  --border: #2e313b;
  --accent: #748ffc;
  --accent-soft: #28304a;
  --good: #51cf66;
  --good-soft: #1c3025;
  --bad: #ff8787;
  --bad-soft: #3a2326;
  --shadow: 0 1px 3px rgba(0, 0, 0, .3), 0 6px 20px rgba(0, 0, 0, .35);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* ---------- Header / nav ---------- */
header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: color-mix(in srgb, var(--surface) 86%, transparent);
  backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--border);
}
.bar {
  max-width: 920px;
  margin: 0 auto;
  padding: 10px 16px;
  display: flex;
  align-items: center;
  gap: 12px;
}
.brand {
  font-weight: 800;
  font-size: 1.1rem;
  letter-spacing: -.01em;
  display: flex;
  align-items: center;
  gap: 8px;
  margin-right: auto;
}
.brand .logo {
  font-size: 1.4rem;
  background: var(--accent-soft);
  color: var(--accent);
  border-radius: 10px;
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
}
.theme-btn {
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  border-radius: 10px;
  width: 38px;
  height: 38px;
  font-size: 1.1rem;
  cursor: pointer;
}
.theme-btn:hover { background: var(--surface-2); }

nav.tabs {
  max-width: 920px;
  margin: 0 auto;
  padding: 0 10px 8px;
  display: flex;
  gap: 4px;
  overflow-x: auto;
  scrollbar-width: none;
}
nav.tabs::-webkit-scrollbar { display: none; }
.tab {
  flex: 0 0 auto;
  border: none;
  background: transparent;
  color: var(--muted);
  font-family: inherit;
  font-size: .92rem;
  font-weight: 600;
  padding: 8px 14px;
  border-radius: 999px;
  cursor: pointer;
  white-space: nowrap;
}
.tab:hover { color: var(--text); background: var(--surface-2); }
.tab.active { color: #fff; background: var(--accent); }

/* ---------- Layout ---------- */
main {
  max-width: 920px;
  margin: 0 auto;
  padding: 22px 16px 80px;
}
section.view { display: none; animation: fade .25s ease; }
section.view.active { display: block; }
@keyframes fade { from { opacity: 0; transform: translateY(4px); } to { opacity: 1; transform: none; } }

h1 { font-size: 1.6rem; margin: .2em 0 .1em; letter-spacing: -.02em; }
h2 { font-size: 1.15rem; margin: 1.6em 0 .6em; }
.lede { color: var(--muted); margin: 0 0 1.2em; }
.hint { color: var(--muted); font-size: .9rem; }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 18px;
}

/* ---------- Home ---------- */
.home-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
  gap: 14px;
  margin-top: 18px;
}
.home-card {
  text-align: left;
  cursor: pointer;
  font-family: inherit;
  color: inherit;
}
.home-card:hover { border-color: var(--accent); transform: translateY(-2px); transition: .15s; }
.home-card .big { font-size: 1.8rem; }
.home-card h3 { margin: .4em 0 .2em; font-size: 1.05rem; }
.home-card p { margin: 0; color: var(--muted); font-size: .9rem; }

/* ---------- Letter grids ---------- */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(76px, 1fr));
  gap: 10px;
}
.letter {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 10px 6px 8px;
  text-align: center;
  cursor: pointer;
  transition: .12s;
}
.letter:hover { border-color: var(--accent); background: var(--accent-soft); }
.letter .glyph { font-size: 2rem; line-height: 1.1; font-weight: 600; }
.letter .rom { font-size: .82rem; color: var(--accent); font-weight: 700; }
.letter .name { font-size: .68rem; color: var(--muted); }

/* ---------- Flashcards ---------- */
.fc-stage { display: grid; place-items: center; gap: 16px; margin-top: 10px; }
.flashcard {
  width: 100%;
  max-width: 320px;
  aspect-ratio: 3 / 2;
  perspective: 1000px;
  cursor: pointer;
}
.fc-inner {
  position: relative;
  width: 100%;
  height: 100%;
  transition: transform .5s;
  transform-style: preserve-3d;
}
.flashcard.flipped .fc-inner { transform: rotateY(180deg); }
.fc-face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  border-radius: var(--radius);
  background: var(--surface);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  display: grid;
  place-items: center;
  text-align: center;
  padding: 10px;
}
.fc-face .glyph { font-size: 4.5rem; font-weight: 600; }
.fc-back { transform: rotateY(180deg); }
.fc-back .rom { font-size: 2.2rem; font-weight: 800; color: var(--accent); }
.fc-back .note { color: var(--muted); font-size: .95rem; margin-top: 6px; max-width: 240px; }
.fc-controls { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; }
.fc-progress { color: var(--muted); font-size: .9rem; }

/* ---------- Quiz ---------- */
.quiz-prompt { font-size: 3.4rem; text-align: center; font-weight: 600; margin: 8px 0 4px; }
.quiz-sub { text-align: center; color: var(--muted); margin-bottom: 14px; }
.quiz-options { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.opt {
  padding: 16px;
  font-size: 1.3rem;
  font-weight: 700;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
  font-family: inherit;
}
.opt:hover:not(:disabled) { border-color: var(--accent); }
.opt.correct { background: var(--good-soft); border-color: var(--good); color: var(--good); }
.opt.wrong { background: var(--bad-soft); border-color: var(--bad); color: var(--bad); }
.opt:disabled { cursor: default; }
.scorebar { display: flex; justify-content: space-between; align-items: center; margin-bottom: 12px; color: var(--muted); font-size: .92rem; }

/* ---------- Reading ---------- */
.word-list { display: grid; gap: 12px; }
.word {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
}
.word .ko { font-size: 2.1rem; font-weight: 600; cursor: pointer; }
.word .meta { flex: 1; min-width: 160px; }
.word .meta .rom { color: var(--accent); font-weight: 700; }
.word .meta .mean { color: var(--muted); }
.syllables { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 6px; width: 100%; }
.syl {
  background: var(--surface-2);
  border-radius: 10px;
  padding: 6px 10px;
  text-align: center;
  font-size: .85rem;
}
.syl .block { font-size: 1.5rem; font-weight: 600; }
.syl .parts { color: var(--muted); letter-spacing: .05em; }

/* ---------- Typing ---------- */
.keyboard { display: grid; gap: 8px; margin: 16px 0; }
.kb-row { display: flex; gap: 6px; justify-content: center; }
.kb-row.r2 { padding: 0 18px; }
.kb-row.r3 { padding: 0 40px; }
.key {
  flex: 1 1 0;
  min-width: 0;
  max-width: 64px;
  aspect-ratio: 1 / 1.05;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--surface);
  display: grid;
  place-items: center;
  position: relative;
  padding: 4px;
}
.key .j { font-size: 1.3rem; font-weight: 600; }
.key .j2 { position: absolute; top: 3px; right: 5px; font-size: .7rem; color: var(--muted); }
.key .lat { position: absolute; bottom: 2px; left: 5px; font-size: .62rem; color: var(--muted); }
.key.target { background: var(--accent-soft); border-color: var(--accent); box-shadow: 0 0 0 2px var(--accent); }
.key.hit { background: var(--good-soft); border-color: var(--good); }
.key.miss { background: var(--bad-soft); border-color: var(--bad); }
.type-prompt { text-align: center; }
.type-prompt .glyph { font-size: 4rem; font-weight: 600; line-height: 1.1; }
.type-prompt .ask { color: var(--muted); }
.type-input {
  display: block;
  width: 100%;
  max-width: 260px;
  margin: 10px auto 0;
  padding: 12px;
  text-align: center;
  font-size: 1.4rem;
  font-family: inherit;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--surface);
  color: var(--text);
}
.type-input:focus { outline: none; border-color: var(--accent); }

/* ---------- Buttons ---------- */
.btn {
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-family: inherit;
  font-weight: 600;
  font-size: .92rem;
  padding: 9px 16px;
  border-radius: 10px;
  cursor: pointer;
}
.btn:hover { background: var(--surface-2); }
.btn.primary { background: var(--accent); color: #fff; border-color: transparent; }
.btn.primary:hover { filter: brightness(1.05); }
.row { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.seg { display: inline-flex; border: 1px solid var(--border); border-radius: 10px; overflow: hidden; }
.seg button {
  border: none; background: var(--surface); color: var(--muted);
  padding: 8px 14px; font-family: inherit; font-weight: 600; font-size: .9rem; cursor: pointer;
}
.seg button.active { background: var(--accent); color: #fff; }

footer {
  max-width: 920px;
  margin: 0 auto;
  padding: 24px 16px 40px;
  color: var(--muted);
  font-size: .85rem;
  text-align: center;
}

@media (max-width: 480px) {
  .fc-face .glyph { font-size: 3.6rem; }
  .quiz-prompt { font-size: 2.8rem; }
  .key .j { font-size: 1.05rem; }
}