:root {
  --bg: #f5f4f8;
  --fg: #1b1a22;
  --muted: #6b6878;
  --accent: #e23b54;
  --accent-2: #ff6b6b;
  --card: #ffffff;
  --card-2: #fbfbfd;
  --line: #e7e5ee;
  --good: #1f9d57;
  --mid: #c98a00;
  --bad: #d23b3b;
  --shadow: 0 1px 2px rgba(20, 18, 40, 0.04), 0 8px 24px rgba(20, 18, 40, 0.06);
  --shadow-sm: 0 1px 2px rgba(20, 18, 40, 0.05), 0 2px 8px rgba(20, 18, 40, 0.05);
  --radius: 18px;
  --radius-sm: 12px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #100f15;
    --fg: #f0eef6;
    --muted: #9b96aa;
    --accent: #ff5470;
    --accent-2: #ff7a7a;
    --card: #1a1922;
    --card-2: #201f2a;
    --line: #2a2834;
    --shadow: 0 1px 2px rgba(0,0,0,0.3), 0 10px 30px rgba(0,0,0,0.35);
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.3), 0 3px 10px rgba(0,0,0,0.25);
  }
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

html, body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: ui-rounded, "SF Pro Rounded", -apple-system, BlinkMacSystemFont,
    "Segoe UI", Roboto, "Hiragino Maru Gothic ProN", "Hiragino Kaku Gothic ProN",
    "Yu Gothic", system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

#app {
  max-width: 600px;
  margin: 0 auto;
  padding: 0.75rem 1.1rem 5rem;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

/* ---- Top bar ---- */
#topbar {
  display: grid;
  grid-template-columns: 2.5rem 1fr 2.5rem;
  align-items: center;
  padding: 0.5rem 0 0.25rem;
  position: sticky;
  top: 0;
  background: linear-gradient(var(--bg) 70%, transparent);
  z-index: 5;
}
#app-title {
  font-size: 1.4rem;
  margin: 0;
  text-align: center;
  letter-spacing: 0.04em;
  background: linear-gradient(120deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  font-weight: 800;
}
.icon-btn {
  width: 2.4rem; height: 2.4rem;
  border-radius: 50%;
  border: 1px solid var(--line);
  background: var(--card);
  color: var(--fg);
  font-size: 1.2rem;
  cursor: pointer;
  box-shadow: var(--shadow-sm);
  display: flex; align-items: center; justify-content: center;
}
.streak {
  justify-self: end;
  font-size: 0.85rem;
  font-weight: 700;
  white-space: nowrap;
}

.screen { display: flex; flex-direction: column; gap: 1rem; animation: fade 0.25s ease; }
@keyframes fade { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }

.label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--muted);
  font-weight: 700;
}

/* ---- Home: stats ---- */
.stats {
  display: flex;
  gap: 0.6rem;
}
.stat-tile {
  flex: 1;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 0.75rem;
  text-align: center;
  box-shadow: var(--shadow-sm);
}
.stat-num { font-size: 1.5rem; font-weight: 800; line-height: 1; }
.stat-lbl { font-size: 0.7rem; color: var(--muted); margin-top: 0.3rem; }

.review-btn {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}

/* ---- Home: lesson map ---- */
#lesson-map { display: flex; flex-direction: column; gap: 1.5rem; }
.section-block { display: flex; flex-direction: column; gap: 0.7rem; }
.section-head {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}
.section-title { font-size: 1.05rem; font-weight: 800; margin: 0; }
.section-rule { flex: 1; height: 1px; background: var(--line); }

button.lesson-tile {
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
  text-align: left;
  width: 100%;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1rem 1.1rem;
  cursor: pointer;
  box-shadow: var(--shadow-sm);
  transition: transform 0.08s ease, box-shadow 0.15s ease;
}
button.lesson-tile:active { transform: scale(0.99); }
.tile-top { display: flex; align-items: flex-start; justify-content: space-between; gap: 0.75rem; }
.tile-title { font-size: 1.1rem; font-weight: 700; line-height: 1.25; }
.tile-grammar { font-size: 0.78rem; color: var(--muted); margin-top: 0.2rem; }
.tile-badge {
  font-size: 0.7rem;
  font-weight: 700;
  padding: 0.25rem 0.55rem;
  border-radius: 999px;
  white-space: nowrap;
}
.badge-new   { background: color-mix(in srgb, var(--accent) 14%, transparent); color: var(--accent); }
.badge-due   { background: color-mix(in srgb, var(--mid) 18%, transparent); color: var(--mid); }
.badge-done  { background: color-mix(in srgb, var(--good) 16%, transparent); color: var(--good); }

.tile-bar { height: 7px; border-radius: 999px; background: var(--line); overflow: hidden; }
.tile-bar > i { display: block; height: 100%; border-radius: 999px; background: linear-gradient(90deg, var(--accent), var(--accent-2)); transition: width 0.4s ease; }

/* ---- Lesson intro ---- */
#lesson-title { font-size: 1.55rem; margin: 0; line-height: 1.25; }
.lesson-grammar {
  align-self: flex-start;
  background: linear-gradient(120deg, var(--accent), var(--accent-2));
  color: #fff;
  font-size: 0.85rem;
  font-weight: 700;
  padding: 0.4rem 0.8rem;
  border-radius: 999px;
  box-shadow: var(--shadow-sm);
}
.lesson-note { margin: 0; color: var(--muted); font-size: 0.98rem; line-height: 1.55; }
.tap-hint { text-transform: none; letter-spacing: 0; font-size: 0.68rem; opacity: 0.7; margin-left: 0.4rem; font-weight: 500; }

.vocab-list { display: flex; flex-direction: column; gap: 0.45rem; }
button.vocab-row {
  display: grid;
  grid-template-columns: 6.5rem 6.5rem 1fr;
  align-items: baseline;
  gap: 0.5rem;
  text-align: left;
  padding: 0.6rem 0.85rem;
  border: 1px solid;
  border-radius: var(--radius-sm);
  width: 100%;
  cursor: pointer;
  transition: transform 0.06s ease;
}
button.vocab-row:active { transform: scale(0.99); }
.vocab-row .v-jp { font-size: 1.25rem; font-weight: 700; }
.vocab-row .v-romaji { font-size: 0.82rem; opacity: 0.85; font-style: italic; }
.vocab-row .v-en { font-size: 0.92rem; }

/* ---- Drill ---- */
#progress-bar { height: 8px; border-radius: 999px; background: var(--line); overflow: hidden; }
#progress-fill { height: 100%; width: 0; border-radius: 999px; background: linear-gradient(90deg, var(--accent), var(--accent-2)); transition: width 0.35s ease; }

#card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.5rem 1.3rem;
  min-height: 190px;
  display: flex;
  flex-direction: column;
  gap: 1.1rem;
  box-shadow: var(--shadow);
}
#prompt-en { font-size: 1.55rem; line-height: 1.35; font-weight: 600; }

#hint-row { font-size: 0.95rem; }
#hint {
  margin-top: 0.5rem;
  padding: 0.6rem 0.8rem;
  background: var(--card-2);
  border-left: 3px solid var(--accent);
  border-radius: 6px;
  color: var(--muted);
  font-size: 0.9rem;
}

#reveal-area { border-top: 1px dashed var(--line); padding-top: 1rem; display: flex; flex-direction: column; gap: 0.4rem; }
#answer-kana { font-size: 1.7rem; line-height: 1.4; font-weight: 700; }
#answer-romaji { font-size: 0.95rem; color: var(--muted); font-style: italic; }

/* ---- Word breakdown chips ---- */
.word-breakdown { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-top: 0.6rem; padding-top: 0.85rem; border-top: 1px dashed var(--line); }
.word-chip { display: flex; flex-direction: column; align-items: center; padding: 0.35rem 0.55rem; border-radius: 10px; border: 1px solid; text-align: center; min-width: 2.5rem; line-height: 1.15; }
.wc-jp { font-size: 1rem; font-weight: 700; }
.wc-en { font-size: 0.65rem; margin-top: 0.15rem; opacity: 0.85; }

/* Part-of-speech colors — light */
.pos-n    { background: #dbeafe; border-color: #93c5fd; color: #1e3a8a; }
.pos-v    { background: #fef3c7; border-color: #fbbf24; color: #78350f; }
.pos-adj  { background: #ede9fe; border-color: #a78bfa; color: #4c1d95; }
.pos-adv  { background: #d1fae5; border-color: #6ee7b7; color: #064e3b; }
.pos-prt  { background: #f1f1f5; border-color: #d4d3dd; color: #45434f; }
.pos-cop  { background: #f1f1f5; border-color: #d4d3dd; color: #45434f; }
.pos-expr { background: #fee2e2; border-color: #fca5a5; color: #7f1d1d; }
.pos-aux  { background: #fef9c3; border-color: #fde047; color: #713f12; }
.pos-conj { background: #ccfbf1; border-color: #5eead4; color: #134e4a; }

@media (prefers-color-scheme: dark) {
  .pos-n    { background: #1c3357; border-color: #3b82f6; color: #bfdbfe; }
  .pos-v    { background: #3d2407; border-color: #d97706; color: #fde68a; }
  .pos-adj  { background: #2c1065; border-color: #7c3aed; color: #ddd6fe; }
  .pos-adv  { background: #06433a; border-color: #059669; color: #a7f3d0; }
  .pos-prt  { background: #26252f; border-color: #4b4956; color: #cbc9d6; }
  .pos-cop  { background: #26252f; border-color: #4b4956; color: #cbc9d6; }
  .pos-expr { background: #45161a; border-color: #dc2626; color: #fecaca; }
  .pos-aux  { background: #3a2906; border-color: #ca8a04; color: #fef08a; }
  .pos-conj { background: #06302c; border-color: #14b8a6; color: #99f6e4; }
}

/* ---- Buttons ---- */
button { font: inherit; cursor: pointer; transition: transform 0.06s ease, box-shadow 0.15s ease, background 0.15s ease; }
button:active { transform: scale(0.97); }
button:disabled { opacity: 0.4; cursor: not-allowed; }

#controls { display: flex; gap: 0.55rem; flex-wrap: wrap; }
button.primary, button.secondary {
  border-radius: 999px;
  padding: 0.9rem 1.2rem;
  font-size: 1rem;
  border: 1px solid var(--line);
}
button.primary {
  background: linear-gradient(120deg, var(--accent), var(--accent-2));
  color: #fff;
  border-color: transparent;
  font-weight: 700;
  flex: 1;
  min-width: 170px;
  box-shadow: 0 6px 18px color-mix(in srgb, var(--accent) 35%, transparent);
}
button.secondary { background: var(--card); color: var(--fg); box-shadow: var(--shadow-sm); }
button.link { background: none; border: none; color: var(--muted); text-decoration: underline; padding: 0.25rem 0; font-size: 0.85rem; }

#grade .grade-row { display: flex; gap: 0.5rem; }
button.grade { flex: 1; padding: 1rem 0.5rem; font-weight: 700; border-radius: var(--radius-sm); border: 1.5px solid var(--line); background: var(--card); box-shadow: var(--shadow-sm); }
button.grade.nope { color: var(--bad); border-color: color-mix(in srgb, var(--bad) 45%, var(--line)); }
button.grade.kinda { color: var(--mid); border-color: color-mix(in srgb, var(--mid) 45%, var(--line)); }
button.grade.got { color: var(--good); border-color: color-mix(in srgb, var(--good) 45%, var(--line)); }

/* ---- Lesson complete ---- */
#lesson-done { text-align: center; align-items: center; padding: 2rem 0; }
.done-emoji { font-size: 3rem; }
#lesson-done h2 { margin: 0.25rem 0 0; font-size: 1.7rem; }
.done-actions { display: flex; gap: 0.6rem; justify-content: center; margin-top: 1.25rem; flex-wrap: wrap; width: 100%; }

footer { margin-top: auto; display: flex; justify-content: center; font-size: 0.8rem; color: var(--muted); }
#voice-warn { color: var(--bad); font-size: 0.75rem; text-align: center; }