:root {
  --bg: #f6f4ef;
  --panel: #fffdf8;
  --panel-2: #f0ece3;
  --fg: #1d1b18;
  --muted: #7a746a;
  --line: #ddd6c9;
  --ink: #1d1b18;
  --ghost: #d9d2c4;
  --accent: #c8432b;
  --accent-fg: #fff;
  --good: #3c8a4a;
  --good-bg: #e3f1e5;
  --bad: #c8432b;
  --bad-bg: #f8e3df;
  --young: #d8a32a;
  --mature: #3c8a4a;
  --radius: 12px;
  --jp: "Hiragino Mincho ProN", "Yu Mincho", "Noto Serif CJK JP", "Noto Serif JP", serif;
  color-scheme: light;
}
:root[data-theme="dark"] {
  --bg: #161513; --panel: #201e1b; --panel-2: #2a2723; --fg: #ece7dd; --muted: #958e82; --line: #36322c;
  --ink: #ece7dd; --ghost: #3d3830; --accent: #e0674e; --accent-fg: #1a1210; --good: #69b878; --good-bg: #1f3323;
  --bad: #e0674e; --bad-bg: #3a221d; --young: #d9ac45; --mature: #69b878;
  color-scheme: dark;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #161513; --panel: #201e1b; --panel-2: #2a2723; --fg: #ece7dd; --muted: #958e82; --line: #36322c;
    --ink: #ece7dd; --ghost: #3d3830; --accent: #e0674e; --accent-fg: #1a1210; --good: #69b878; --good-bg: #1f3323;
    --bad: #e0674e; --bad-bg: #3a221d; --young: #d9ac45; --mature: #69b878;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.45 system-ui, -apple-system, "Segoe UI", sans-serif;
  -webkit-tap-highlight-color: transparent;
}
a { color: var(--accent); }
h1, h2, h3 { margin: 0.4em 0; }
.title { font-size: 24px; }
.muted { color: var(--muted); }
.small { font-size: 13px; }
.hidden { display: none !important; }
.jp, .word, .kanji-char, .kanji-wall, .grid-cell, .choice.jp, .example .ja, .kb-c { font-family: var(--jp); }

#app { min-height: 100vh; display: flex; flex-direction: column; }
.screen {
  flex: 1;
  width: 100%;
  max-width: 560px;
  margin: 0 auto;
  padding: 12px 16px 88px;
}

/* ---- navigation ---- */
.tabbar {
  position: fixed; bottom: 0; left: 0; right: 0;
  display: flex; justify-content: center;
  background: var(--panel); border-top: 1px solid var(--line);
  padding-bottom: env(safe-area-inset-bottom);
  z-index: 10;
}
.tabbar a {
  flex: 1; max-width: 140px; text-align: center; padding: 14px 0;
  color: var(--muted); text-decoration: none; font-weight: 600; font-size: 14px;
}
.tabbar a.on { color: var(--accent); }
.tabbar .brand { display: none; }

/* Desktop / tablet: the bar becomes a sticky header at the top (phones keep it at the
   bottom, within thumb reach). */
@media (min-width: 768px) {
  .tabbar {
    position: sticky; top: 0; bottom: auto; order: -1;
    border-top: none; border-bottom: 1px solid var(--line);
    padding: 0 max(16px, calc((100% - 960px) / 2));
    justify-content: flex-end; gap: 4px;
  }
  .tabbar a { flex: 0 0 auto; max-width: none; padding: 16px 14px; font-size: 15px; border-bottom: 2px solid transparent; }
  .tabbar a.on { border-bottom-color: var(--accent); }
  .tabbar a:hover { color: var(--fg); }
  .tabbar .brand { display: block; margin-right: auto; padding-left: 0; color: var(--fg); font-size: 17px; }
  .screen { padding-bottom: 40px; }
  .toast { bottom: 32px; }
  .home-title { display: none; } /* the top bar already shows the name */
}

/* ---- building blocks ---- */
.card {
  background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 14px 16px; margin: 12px 0;
}
.row { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; margin: 8px 0; }
.row.between { justify-content: space-between; }
.row.center { justify-content: center; }
.row.end { justify-content: flex-end; }
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  font: inherit; font-weight: 600; color: var(--fg); background: var(--panel-2);
  border: 1px solid var(--line); border-radius: 10px; padding: 10px 18px;
  text-decoration: none; cursor: pointer; min-height: 44px;
}
.btn:active { transform: translateY(1px); }
.btn.primary { background: var(--accent); color: var(--accent-fg); border-color: var(--accent); }
.btn.disabled, .btn:disabled { opacity: 0.45; pointer-events: none; }
.btn.small { padding: 6px 12px; min-height: 34px; font-size: 14px; }
.btn.danger { color: var(--bad); border-color: var(--bad); background: transparent; }
.icon-btn {
  background: none; border: none; color: var(--muted); font-size: 18px; cursor: pointer;
  padding: 6px 8px; border-radius: 8px;
}
.icon-btn:hover { color: var(--fg); }
.banner { padding: 10px 14px; border-radius: var(--radius); margin: 8px 0; }
.banner.bad { background: var(--bad-bg); color: var(--bad); }
.label { font-weight: 700; }
.big-number { font-size: 40px; font-weight: 700; line-height: 1; }
.seg { display: inline-flex; border: 1px solid var(--line); border-radius: 10px; overflow: hidden; }
.seg button {
  font: inherit; font-size: 14px; border: none; background: var(--panel); color: var(--fg);
  padding: 7px 12px; cursor: pointer; border-left: 1px solid var(--line);
}
.seg button:first-child { border-left: none; }
.seg button.on { background: var(--fg); color: var(--bg); }
ruby { ruby-align: center; }
ruby rt { font-size: 0.42em; color: var(--muted); font-family: system-ui, sans-serif; }

/* ---- home ---- */
.preview { list-style: none; padding: 0; margin: 10px 0 0; }
.preview li { padding: 6px 0; border-top: 1px solid var(--line); display: flex; gap: 6px; align-items: baseline; flex-wrap: wrap; }
.preview li.learned { opacity: 0.5; }
.preview .jp { font-size: 20px; }
.preview-meaning { margin-left: auto; color: var(--muted); font-size: 14px; text-align: right; max-width: 60%; }
.stats .stat { margin: 4px 0; }
.forecast { display: flex; gap: 6px; align-items: flex-end; height: 90px; margin-top: 12px; }
.fc-day { flex: 1; display: flex; flex-direction: column; align-items: center; justify-content: flex-end; height: 100%; }
.fc-bar { width: 100%; background: var(--accent); opacity: 0.7; border-radius: 4px 4px 0 0; min-height: 2px; }
.fc-n { font-size: 12px; font-weight: 600; }
.fc-label { font-size: 11px; color: var(--muted); }

/* ---- lessons ---- */
details.level { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); margin: 10px 0; overflow: hidden; }
details.level summary { padding: 12px 16px; font-weight: 700; cursor: pointer; display: flex; justify-content: space-between; }
.lesson-row {
  display: flex; gap: 10px; align-items: center; padding: 10px 16px; border-top: 1px solid var(--line);
  color: var(--fg); text-decoration: none;
}
.lesson-row.done { opacity: 0.55; }
.lesson-row.next { background: var(--panel-2); }
.lesson-n { width: 3.2em; color: var(--muted); font-size: 13px; }
.lesson-words { flex: 1; font-size: 18px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.lesson-status { font-size: 12px; color: var(--muted); }
.lesson-row.next .lesson-status { color: var(--accent); font-weight: 700; }
.lesson-row.partial .lesson-status { color: var(--young); }

/* ---- sessions ---- */
.session-head { display: flex; align-items: center; gap: 8px; }
.session-title { font-weight: 700; }
.progress-label { margin-left: auto; color: var(--muted); font-size: 14px; }
.progress { height: 4px; background: var(--line); border-radius: 2px; overflow: hidden; margin: 6px 0 12px; }
.progress-fill { height: 100%; background: var(--accent); transition: width 0.3s; width: 0; }
.step {
  position: relative; background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 18px 16px; text-align: center;
}
.step > .corner + * { margin-top: 30px; } /* keep the prompt clear of the corner button */
.step.done { padding: 28px 16px; }
.corner {
  position: absolute; top: 8px; right: 8px; font: inherit; font-size: 12px;
  background: none; border: 1px solid var(--line); color: var(--muted); border-radius: 8px;
  padding: 4px 8px; cursor: pointer;
}
.corner:disabled { opacity: 0.35; cursor: default; }
.corner:not(:disabled) { color: var(--fg); }
.prompt { margin: 14px 0 10px; }
.question { color: var(--muted); font-size: 14px; margin-bottom: 6px; }
.word.big { font-size: 48px; line-height: 1.5; }
.word.huge { font-size: 56px; line-height: 1.5; }
.kana { font-size: 22px; display: inline-flex; align-items: center; gap: 4px; }
.speak { font-size: 18px; }
.hint-meaning, .meaning { color: var(--muted); margin: 6px 0; }
.meaning-big { font-size: 22px; font-weight: 600; }
.readings { color: var(--muted); display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.choices { display: grid; gap: 8px; margin-top: 12px; }
.choice {
  display: flex; align-items: center; gap: 10px; text-align: left; font: inherit; color: var(--fg);
  background: var(--panel-2); border: 2px solid transparent; border-radius: 10px;
  padding: 12px 14px; cursor: pointer; min-height: 52px;
}
.choice.jp .label { font-size: 22px; }
.choices.many { gap: 6px; }
.choices.many .choice { min-height: 40px; padding: 6px 10px; font-size: 14px; line-height: 1.25; }
.choices.many:not(.cols) .label { display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.word-line { display: flex; align-items: center; justify-content: center; gap: 4px; }
.choices.many.cols { grid-template-columns: 1fr 1fr; }
.choices.many.jp .label, .choices.many.cols .label { font-size: 19px; }
.choice .key { font-size: 12px; color: var(--muted); width: 1em; font-family: system-ui, sans-serif; }
.choice:disabled { cursor: default; }
.choice.right { border-color: var(--good); background: var(--good-bg); }
.choice.wrong { border-color: var(--bad); background: var(--bad-bg); }
.blanked { display: flex; gap: 2px; justify-content: center; align-items: center; margin-top: 4px; }
.blank {
  display: inline-flex; align-items: center; justify-content: center;
  width: 1.1em; height: 1.1em; line-height: 1; margin: 0 2px;
  border: 2px dashed var(--accent); border-radius: 8px;
}
.blank.right { border: 2px solid transparent; color: var(--good); }
.blank.wrong { border: 2px solid var(--bad); color: var(--bad); }
.kanji-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin: 14px auto 6px; max-width: 320px; }
.kanji-grid.wide { grid-template-columns: repeat(4, 1fr); max-width: 400px; }
.grid-cell {
  aspect-ratio: 1; font-size: 36px; background: var(--panel-2); color: var(--fg);
  border: 1px solid var(--line); border-radius: 10px; cursor: pointer;
}
.grid-cell:active { background: var(--line); }
.verdict { font-weight: 700; margin-bottom: 4px; }
.verdict.ok { color: var(--good); }
.verdict.bad { color: var(--bad); }
.kanji-breakdown { display: flex; gap: 8px; justify-content: center; flex-wrap: wrap; margin: 10px 0; }
.kb {
  display: flex; flex-direction: column; align-items: center; text-decoration: none; color: var(--fg);
  background: var(--panel-2); border-radius: 8px; padding: 4px 10px; min-width: 56px;
}
.kb-c { font-size: 24px; }
.kb-m { font-size: 11px; color: var(--muted); }
.example { margin: 12px 0 4px; padding: 10px; background: var(--panel-2); border-radius: 10px; }
.example .ja { font-size: 18px; display: flex; align-items: center; justify-content: center; gap: 4px; flex-wrap: wrap; }
.example .en { color: var(--muted); font-size: 14px; }
.rate-row { margin-top: 16px; }
.rate { flex: 1; flex-direction: column; gap: 0; max-width: 140px; }
.rate small { font-weight: 400; font-size: 12px; opacity: 0.8; }
.rate.r2 { border-color: var(--young); }
.rate.r3 { background: var(--accent); color: var(--accent-fg); border-color: var(--accent); }
.rate.r4 { border-color: var(--good); }

/* ---- drawing ---- */
.drawpad-wrap { width: min(100%, 340px, max(180px, calc(100dvh - var(--chrome, 432px)))); margin: 8px auto 0; }
.kanji-panel { --chrome: 385px; }
.drawpad {
  width: 100%; aspect-ratio: 1; display: block; background: var(--bg);
  border-radius: var(--radius); touch-action: none; cursor: crosshair;
}
.drawpad-msg { min-height: 1.4em; font-size: 14px; margin-top: 4px; }
.drawpad-msg.bad { color: var(--bad); }
.grid rect { fill: none; stroke: var(--line); stroke-width: 0.6; }
.grid line { stroke: var(--line); stroke-width: 0.4; stroke-dasharray: 2 2; }
svg path, svg polyline { fill: none; stroke-linecap: round; stroke-linejoin: round; }
.ghost path { stroke: var(--ghost); stroke-width: 4; }
.ghost path.next { stroke: var(--muted); }
.ghost circle { fill: var(--accent); }
.done path { stroke: var(--ink); stroke-width: 4; }
.done path.fresh { animation: settle 0.25s ease-out; }
.done.complete path { stroke: var(--good); transition: stroke 0.3s; }
.hint path { stroke: var(--accent); stroke-width: 4; opacity: 0.8; }
.hint circle { fill: var(--accent); }
.ink polyline { stroke: var(--ink); stroke-width: 3.5; opacity: 0.7; }
.ink polyline.bad { stroke: var(--bad); transition: opacity 0.4s; opacity: 0; }
@keyframes settle { from { opacity: 0.4; } to { opacity: 1; } }

/* ---- kanji ---- */
.kanji-detail {
  display: grid; grid-template-columns: 1fr 1fr; gap: 12px; align-items: center; text-align: center;
  margin: 14px 0; background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 14px;
}
@media (max-width: 480px) { .kanji-detail { grid-template-columns: 1fr; } }
.kanji-panel { margin-top: 6px; }
.kanji-head { display: flex; gap: 14px; align-items: center; justify-content: center; text-align: left; }
.kanji-head .kanji-char { font-size: 60px; line-height: 1.1; }
.kanji-head .meaning { margin: 0 0 2px; color: var(--fg); font-weight: 600; }
.readings.left { justify-content: flex-start; font-size: 14px; gap: 2px 10px; }
.kanji-char { font-size: 72px; line-height: 1.2; }
.kanji-info .readings { flex-direction: column; gap: 2px; }
.pad-holder .drawpad-wrap { margin-top: 0; }
.legend { display: flex; gap: 12px; font-size: 13px; margin: 10px 0; flex-wrap: wrap; }
.legend span::before { content: ''; display: inline-block; width: 10px; height: 10px; border-radius: 3px; margin-right: 4px; vertical-align: -1px; }
.legend .k-new::before { background: var(--panel-2); border: 1px solid var(--line); }
.legend .k-young::before { background: var(--young); }
.legend .k-mature::before { background: var(--mature); }
.kanji-wall { display: grid; grid-template-columns: repeat(auto-fill, minmax(44px, 1fr)); gap: 4px; }
.kanji-wall a {
  aspect-ratio: 1; display: grid; place-items: center; font-size: 24px; text-decoration: none;
  border-radius: 8px; color: var(--fg); background: var(--panel); border: 1px solid var(--line);
}
.kanji-wall a.k-new { color: var(--muted); }
.kanji-wall a.k-young { background: var(--young); color: #1d1b18; border-color: transparent; }
.kanji-wall a.k-mature { background: var(--mature); color: #fff; border-color: transparent; }
.k-status { display: inline-block; padding: 2px 10px; border-radius: 10px; font-size: 13px; margin-top: 6px; background: var(--panel-2); }
.k-status.k-young { background: var(--young); color: #1d1b18; }
.k-status.k-mature { background: var(--mature); color: #fff; }
.word-list { list-style: none; padding: 0; margin: 0; background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); }
.word-list li { display: flex; gap: 10px; align-items: center; padding: 8px 14px; border-top: 1px solid var(--line); }
.word-list li:first-child { border-top: none; }
.word-list li::before { content: ''; width: 8px; height: 8px; border-radius: 50%; background: var(--line); flex: none; }
.word-list li.stage-young::before { background: var(--young); }
.word-list li.stage-mature::before { background: var(--mature); }
.wl-word { font-size: 22px; min-width: 4em; }
.wl-meaning { flex: 1; color: var(--muted); font-size: 14px; }
.wl-lesson { font-size: 12px; }

/* ---- settings ---- */
.settings h3 { font-size: 16px; }
.setting { display: flex; gap: 12px; justify-content: space-between; align-items: center; padding: 10px 0; border-top: 1px solid var(--line); flex-wrap: wrap; }
.setting-text { display: flex; flex-direction: column; flex: 1 1 200px; }
.setting-text small { font-size: 12px; }
.tag { font-size: 11px; color: var(--muted); }
.setting select, .setting input[type="range"] { font: inherit; }
.setting select { background: var(--panel-2); color: var(--fg); border: 1px solid var(--line); border-radius: 8px; padding: 6px 8px; max-width: 220px; }
.setting input[type="checkbox"] { width: 22px; height: 22px; accent-color: var(--accent); }
.range { display: flex; align-items: center; gap: 8px; }
.range input { accent-color: var(--accent); width: 150px; }
.range output { min-width: 3em; text-align: right; font-variant-numeric: tabular-nums; }

/* ---- overlays ---- */
.overlay { position: fixed; inset: 0; background: rgba(0, 0, 0, 0.45); display: grid; place-items: center; z-index: 50; padding: 16px; }
.dialog { background: var(--panel); border-radius: var(--radius); padding: 18px; max-width: 380px; width: 100%; }
.toast {
  position: fixed; left: 50%; bottom: 90px; transform: translate(-50%, 20px); opacity: 0;
  background: var(--fg); color: var(--bg); padding: 10px 16px; border-radius: 10px; z-index: 60;
  transition: opacity 0.25s, transform 0.25s; max-width: 90vw; text-align: center;
}
.toast.show { opacity: 1; transform: translate(-50%, 0); }
.summary-body > .word.huge:first-child { margin-top: 6px; }

/* ---- import ---- */
.wall-level { font-weight: 700; color: var(--muted); margin: 12px 0 6px; font-size: 13px; }
.kanji-wall.selectable button {
  aspect-ratio: 1; font: inherit; font-family: var(--jp); font-size: 22px; padding: 0; cursor: pointer;
  border-radius: 8px; color: var(--muted); background: var(--panel-2); border: 1px solid var(--line);
}
.kanji-wall.selectable button.on { background: var(--mature); color: #fff; border-color: transparent; }
.kanji-wall.selectable button.locked { opacity: 0.55; cursor: default; }
.paste {
  width: 100%; font: inherit; color: var(--fg); background: var(--panel-2); border: 1px solid var(--line);
  border-radius: 10px; padding: 8px 10px; margin-top: 8px; resize: vertical;
}
.load-chart { display: flex; align-items: flex-end; gap: 1px; height: 70px; margin: 12px 0 4px; }
.load-bar { flex: 1; background: var(--accent); opacity: 0.75; border-radius: 2px 2px 0 0; min-height: 1px; }
details summary { cursor: pointer; }

/* ---- short phones: keep every exercise on one screen ---- */
.session-head { min-height: 40px; }
@media (max-height: 760px) {
  .screen { padding-top: 6px; }
  .progress { margin: 4px 0 8px; }
  .step { padding: 12px 12px; }
  .step > .corner + * { margin-top: 24px; }
  .corner { top: 6px; right: 6px; padding: 3px 7px; }
  .prompt { margin: 4px 0 6px; }
  .question { margin-bottom: 2px; }
  .word.big { font-size: 40px; line-height: 1.35; }
  .word.huge { font-size: 46px; line-height: 1.35; }
  .kana { font-size: 20px; }
  .choices { margin-top: 8px; gap: 6px; }
  .choice { min-height: 46px; padding: 8px 12px; }
  .hint-meaning, .meaning { margin: 3px 0; }
  .kanji-grid { gap: 6px; margin: 8px auto 4px; max-width: 280px; }
  .kanji-grid.wide { max-width: 330px; }
  .grid-cell { font-size: 30px; }
  .example { margin: 8px 0 2px; padding: 8px; }
  .rate-row, .row { margin: 6px 0; }
  .btn { min-height: 42px; padding: 8px 16px; }
  .drawpad-msg { min-height: 1.2em; margin-top: 2px; }
  .choices.many .choice { min-height: 36px; padding: 4px 8px; font-size: 13px; }
}
@media (max-height: 680px) {
  /* 8 translations on a small phone: one line each (the first gloss tells them apart) */
  .choices.many:not(.cols) .label { -webkit-line-clamp: 1; }
}

/* ---- sync ---- */
.sync-pill {
  display: inline-block; font: inherit; font-size: 13px; color: var(--muted); background: none;
  border: 1px solid var(--line); border-radius: 999px; padding: 3px 10px; text-decoration: none; cursor: pointer;
}
.sync-pill.bad { color: var(--bad); border-color: var(--bad); }
.conflict { margin-top: 10px; padding: 12px; border-radius: 10px; background: var(--bad-bg); }
.choices-col { display: grid; gap: 8px; }
.sync-icon { display: inline-flex; vertical-align: -4px; margin-left: 4px; color: var(--muted); }
.sync-icon[hidden] { display: none; }
.sync-icon svg { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }
.sync-icon[data-state="ok"] { color: var(--muted); }
.sync-icon[data-state="busy"] { color: var(--fg); animation: sync-pulse 1.2s ease-in-out infinite; }
.sync-icon[data-state="bad"] { color: var(--bad); }
.sync-icon[data-state="off"], .sync-icon[data-state="offline"] { color: var(--muted); opacity: 0.6; }
.session-head .sync-icon { margin-left: 0; }
@keyframes sync-pulse { 50% { opacity: 0.45; } }

/* ---- static text pages (privacy) ---- */
.prose { line-height: 1.6; }
.prose h3 { margin-top: 1.4em; }
.prose ul { padding-left: 1.2em; }
.prose li { margin: 0.4em 0; }

/* ---- free practice picker ---- */
.picker-wall button {
  aspect-ratio: 1; display: grid; place-items: center; font: inherit; font-family: var(--jp); font-size: 24px;
  border-radius: 8px; color: var(--fg); background: var(--panel); border: 1px solid var(--line); cursor: pointer; padding: 0;
}
.picker-wall button.k-new { color: var(--muted); }
.picker-wall button.sel { background: var(--accent); color: var(--accent-fg); border-color: var(--accent); }
.select-bar {
  position: sticky; bottom: 60px; z-index: 5; margin: 12px 0; padding: 10px 14px;
  background: var(--panel); border: 1px solid var(--accent); border-radius: var(--radius);
}
.select-bar .row { margin: 6px 0 0; }
.select-info { display: flex; flex-wrap: wrap; gap: 4px 10px; align-items: center; }
.select-info label { display: inline-flex; gap: 4px; align-items: center; margin-left: auto; }
@media (min-width: 768px) { .select-bar { bottom: 16px; } }