:root {
  --bg: #f6f3ee;
  --surface: #ffffff;
  --text: #1d1b19;
  --muted: #6b655d;
  --line: #e2dcd3;
  --accent: #b5362e;
  --accent-ink: #ffffff;
  --ok: #2f7d4f;
  --ok-bg: #e4f3ea;
  --warn: #9a6b00;
  --warn-bg: #fbf0d2;
  --bad: #b5362e;
  --bad-bg: #fbe4e2;
  --radius: 14px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-ja: "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", "Yu Gothic", sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #15140f; --surface: #1f1d18; --text: #efe9df; --muted: #a39b8f; --line: #35312a;
    --accent: #e0574d; --accent-ink: #15140f;
    --ok: #6fcf97; --ok-bg: #1d3327; --warn: #e3b341; --warn-bg: #3a2f10; --bad: #e0574d; --bad-bg: #3a1d1b;
  }
}
:root[data-theme="dark"] {
  --bg: #15140f; --surface: #1f1d18; --text: #efe9df; --muted: #a39b8f; --line: #35312a;
  --accent: #e0574d; --accent-ink: #15140f;
  --ok: #6fcf97; --ok-bg: #1d3327; --warn: #e3b341; --warn-bg: #3a2f10; --bad: #e0574d; --bad-bg: #3a1d1b;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html, body { margin: 0; padding: 0; }
body { background: var(--bg); color: var(--text); font-family: var(--font); line-height: 1.45; -webkit-font-smoothing: antialiased; }
button, input, textarea { font: inherit; color: inherit; }
button { cursor: pointer; }
code { font-size: 0.9em; background: var(--line); padding: 0 4px; border-radius: 4px; }

.top { display: flex; align-items: center; justify-content: space-between; padding: 12px 16px; border-bottom: 1px solid var(--line); gap: 12px; flex-wrap: wrap; }
.brand { background: none; border: 0; font-family: var(--font-ja); font-size: 22px; font-weight: 700; padding: 0; display: flex; align-items: baseline; gap: 8px; }
.brand span { font-family: var(--font); font-size: 13px; color: var(--muted); font-weight: 500; }
nav { display: flex; gap: 4px; }
nav button { background: none; border: 1px solid transparent; border-radius: 999px; padding: 6px 12px; color: var(--muted); }
nav button.active, nav button:hover { color: var(--text); border-color: var(--line); }
nav button:focus-visible, button:focus-visible, input:focus-visible, textarea:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.view { max-width: 640px; margin: 0 auto; padding: 16px; }
.panel h1 { font-size: 24px; margin: 8px 0 4px; }
.panel h2 { font-size: 15px; text-transform: uppercase; letter-spacing: 0.06em; color: var(--muted); margin: 24px 0 8px; }
.muted { color: var(--muted); }
.small { font-size: 13px; }

.deck-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 8px; margin: 12px 0; }
.deck { display: flex; flex-direction: column; gap: 2px; text-align: left; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 12px; }
.deck.on { border-color: var(--accent); box-shadow: inset 0 0 0 1px var(--accent); }
.deck strong { font-size: 15px; }
.deck span { font-size: 12px; color: var(--muted); }

.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(110px, 1fr)); gap: 8px; margin: 8px 0; }
.stat { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 10px 12px; }
.stat b { display: block; font-size: 22px; }
.stat span { font-size: 12px; color: var(--muted); }

.modes { display: grid; gap: 8px; }
.mode { text-align: left; display: flex; flex-direction: column; gap: 4px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 14px 16px; }
.mode:hover { border-color: var(--accent); }
.mode strong { font-size: 17px; }
.mode span { color: var(--muted); font-size: 14px; }

.progressbar { height: 4px; background: var(--line); border-radius: 2px; overflow: hidden; margin: 4px 0 8px; }
.progressbar div { height: 100%; background: var(--accent); width: 0; transition: width .2s; }
.study-meta { display: flex; justify-content: space-between; font-size: 13px; color: var(--muted); margin-bottom: 8px; }

.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px 18px; }
.prompt { font-size: 26px; font-weight: 600; min-height: 1.3em; margin-bottom: 14px; }
.prompt.ja { font-family: var(--font-ja); }
.prompt .hint { display: block; font-size: 14px; color: var(--muted); font-weight: 400; margin-top: 4px; }
.audio-row { display: flex; gap: 8px; margin: 8px 0 12px; }
.audio-row button { background: var(--bg); border: 1px solid var(--line); border-radius: 999px; padding: 8px 14px; }

.field { display: flex; flex-direction: column; gap: 6px; margin: 10px 0; }
.field > span { font-size: 13px; color: var(--muted); }
.field input, .field textarea { background: var(--bg); border: 1px solid var(--line); border-radius: 10px; padding: 12px; font-size: 18px; width: 100%; }
.field.check { flex-direction: row; align-items: center; }
.field.check input { width: auto; }

.confidence { border: 0; padding: 0; margin: 12px 0; }
.confidence legend { font-size: 13px; color: var(--muted); margin-bottom: 6px; padding: 0; }
.confidence label { display: inline-flex; align-items: center; margin: 0 6px 6px 0; }
.confidence input { position: absolute; opacity: 0; width: 0; height: 0; }
.confidence span { display: inline-block; padding: 8px 14px; border-radius: 999px; border: 1px solid var(--line); background: var(--bg); }
.confidence input:checked + span { background: var(--text); color: var(--bg); border-color: var(--text); }
.confidence input:focus-visible + span { outline: 2px solid var(--accent); outline-offset: 2px; }

.primary { width: 100%; background: var(--accent); color: var(--accent-ink); border: 0; border-radius: 10px; padding: 14px; font-size: 17px; font-weight: 600; margin-top: 8px; }
.primary:disabled { opacity: .45; cursor: not-allowed; }
.link { background: none; border: 0; color: var(--muted); text-decoration: underline; margin: 16px auto 0; display: block; }
.btn { display: inline-block; background: var(--surface); border: 1px solid var(--line); border-radius: 10px; padding: 10px 14px; cursor: pointer; }
.row { display: flex; gap: 8px; flex-wrap: wrap; }
.row button { background: var(--surface); border: 1px solid var(--line); border-radius: 10px; padding: 10px 14px; }
.row .danger { color: var(--bad); border-color: var(--bad); }

.verdict { padding: 10px 12px; border-radius: 10px; font-weight: 600; margin-bottom: 12px; }
.verdict.ok { background: var(--ok-bg); color: var(--ok); }
.verdict.almost { background: var(--warn-bg); color: var(--warn); }
.verdict.bad { background: var(--bad-bg); color: var(--bad); }
.verdict small { display: block; font-weight: 400; margin-top: 2px; }
.reveal .ja { font-family: var(--font-ja); font-size: 30px; font-weight: 600; }
.reveal .romaji { font-size: 18px; color: var(--muted); }
.reveal .en { font-size: 17px; margin-top: 6px; }
.reveal .notes { font-size: 14px; color: var(--muted); margin-top: 8px; }
.reveal .notes:empty, .reveal .example:empty { display: none; }
.example { margin-top: 12px; padding: 10px 12px; border-left: 3px solid var(--line); font-size: 15px; }
.example .ja { font-size: 18px; font-weight: 500; }
.example .romaji, .example .en { font-size: 14px; }

.players { display: grid; gap: 8px; margin: 14px 0 4px; }
.player { display: flex; align-items: center; justify-content: space-between; gap: 8px; }
.player .name { font-weight: 600; }
.player .grade { display: flex; gap: 6px; }
.player .grade button { border: 1px solid var(--line); background: var(--bg); border-radius: 999px; width: 44px; height: 40px; font-size: 18px; }
.player .grade button.ok.on { background: var(--ok-bg); color: var(--ok); border-color: var(--ok); }
.player .grade button.bad.on { background: var(--bad-bg); color: var(--bad); border-color: var(--bad); }
.scoreboard { margin-top: 14px; display: flex; gap: 8px; flex-wrap: wrap; }
.scoreboard .stat { flex: 1; min-width: 100px; }

.missed { margin: 12px 0; display: grid; gap: 6px; }
.missed .item { background: var(--surface); border: 1px solid var(--line); border-radius: 10px; padding: 10px 12px; }
.missed .item .ja { font-family: var(--font-ja); font-weight: 600; }
.missed .item .tag { font-size: 12px; color: var(--bad); }

.browse-deck { margin: 16px 0; }
.browse-deck table { width: 100%; border-collapse: collapse; font-size: 14px; }
.browse-deck td { padding: 6px 4px; border-top: 1px solid var(--line); vertical-align: top; }
.browse-deck td.ja { font-family: var(--font-ja); white-space: nowrap; }
.browse-deck td.r { color: var(--muted); }
.browse-deck .due { font-size: 12px; color: var(--muted); white-space: nowrap; }

@media (max-width: 480px) {
  .top { padding: 10px 16px; }
  nav button { padding: 6px 9px; font-size: 14px; }
  .prompt { font-size: 22px; }
  .reveal .ja { font-size: 26px; }
}
.field > span em { font-style: normal; font-weight: 400; }

.levels { display: flex; gap: 6px; flex-wrap: wrap; margin: 8px 0 4px; }
.levels button { background: var(--surface); border: 1px solid var(--line); border-radius: 999px; padding: 8px 14px; display: flex; flex-direction: column; align-items: flex-start; line-height: 1.2; }
.levels button span { font-size: 11px; color: var(--muted); }
.levels button.on { background: var(--text); color: var(--bg); border-color: var(--text); }
.levels button.on span { color: var(--bg); opacity: .8; }
.levels button:hover { border-color: var(--accent); }
.lvl { display: inline-block; font-size: 11px; color: var(--muted); border: 1px solid var(--line); border-radius: 4px; padding: 0 5px; margin-left: 6px; vertical-align: middle; }

.tip { margin-top: 12px; padding: 10px 12px; border-radius: 10px; background: var(--bg); border: 1px solid var(--line); font-size: 14px; line-height: 1.5; }
.tip-label { display: block; font-size: 11px; text-transform: uppercase; letter-spacing: 0.06em; color: var(--muted); margin-bottom: 4px; }

.morae { display: flex; flex-wrap: wrap; align-items: flex-end; gap: 2px 0; margin: 8px 0 4px; }
.morae .gap { width: 14px; }
.mora { display: inline-flex; flex-direction: column; align-items: center; background: none; border: 0; padding: 2px 3px 0; border-radius: 6px 6px 0 0; }
.mora .k { font-family: var(--font-ja); font-size: 20px; line-height: 1.2; }
.mora .r { font-size: 13px; line-height: 1.3; padding: 0 2px 2px; border-bottom: 3px solid; min-width: 1.2em; text-align: center; }
.mora.a .r { border-color: var(--accent); }
.mora.b .r { border-color: var(--muted); }
.mora:hover, .mora:focus-visible { background: var(--bg); outline: none; }
.mora:focus-visible .r { border-bottom-width: 4px; }

/* kana section */
.tabs { display: flex; gap: 6px; margin: 8px 0 16px; }
.tabs button { background: var(--surface); border: 1px solid var(--line); border-radius: 999px; padding: 8px 16px; }
.tabs button.on { background: var(--text); color: var(--bg); border-color: var(--text); }
.tabs button:hover { border-color: var(--accent); }
.kana-controls { margin-bottom: 8px; }
.kana-group h2 { margin-top: 18px; }
.kana-grid { display: grid; gap: 6px; }
.kana-grid.cols-5 { grid-template-columns: repeat(5, 1fr); }
.kana-grid.cols-3 { grid-template-columns: repeat(3, 1fr); max-width: 360px; }
.kana-cell { display: flex; flex-direction: column; align-items: center; background: var(--surface); border: 1px solid var(--line); border-radius: 10px; padding: 8px 4px 6px; min-height: 64px; }
.kana-cell.empty { background: none; border: 0; }
.kana-cell .g { font-family: var(--font-ja); font-size: 26px; line-height: 1.1; }
.kana-cell .r { font-size: 12px; color: var(--muted); margin-top: 2px; }
.hide-romaji .kana-cell .r { visibility: hidden; }
.kana-cell.ok { border-color: var(--ok); box-shadow: inset 0 0 0 1px var(--ok); }
.kana-cell.miss { border-color: var(--bad); box-shadow: inset 0 0 0 1px var(--bad); }
.kana-cell:hover { border-color: var(--accent); }
.kana-practice { margin-top: 24px; padding-top: 8px; border-top: 1px solid var(--line); }
.kana-big { font-family: var(--font-ja); font-size: 72px; line-height: 1.1; display: block; text-align: center; padding: 8px 0; }
.kana-big.kanji-prompt { font-size: 44px; }
.kana-choices { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin: 8px 0; }
.kana-choice { font-family: var(--font-ja); font-size: 34px; background: var(--bg); border: 1px solid var(--line); border-radius: 12px; padding: 14px 0; }
.kana-choice:hover { border-color: var(--accent); }
.kanji-list { display: grid; gap: 8px; }
.kanji-card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 12px; }
.kanji-head { display: flex; gap: 12px; align-items: center; }
.kanji-glyph { font-family: var(--font-ja); font-size: 40px; line-height: 1; background: var(--bg); border: 1px solid var(--line); border-radius: 10px; width: 60px; height: 60px; flex: none; }
.kanji-glyph:hover { border-color: var(--accent); }
.kanji-meaning { font-weight: 600; font-size: 16px; }
.kanji-words { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 10px; }
.kanji-word { display: flex; flex-direction: column; align-items: flex-start; text-align: left; background: var(--bg); border: 1px solid var(--line); border-radius: 8px; padding: 6px 10px; }
.kanji-word:hover { border-color: var(--accent); }
.kanji-word .ja { font-family: var(--font-ja); font-size: 16px; }
.kanji-word .r, .kanji-word .e { font-size: 12px; color: var(--muted); }
.kanji-parts { display: flex; flex-wrap: wrap; gap: 6px 14px; margin-top: 8px; font-size: 14px; }
.kanji-parts b { font-family: var(--font-ja); font-size: 18px; margin-right: 4px; }

.tap-speed { margin: 6px 0 10px; }
.tap-speed legend { margin-bottom: 4px; }

.tooltip { position: absolute; z-index: 50; background: var(--text); color: var(--bg); font-size: 12px; line-height: 1.4; padding: 6px 10px; border-radius: 8px; max-width: 260px; pointer-events: none; box-shadow: 0 4px 14px rgba(0,0,0,.25); }
.tooltip[hidden] { display: none; }
.stats + .kana-group h2 { margin-top: 14px; }

.explainer { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); margin: 8px 0 12px; }
.explainer summary { cursor: pointer; padding: 12px 14px; font-weight: 600; list-style: none; display: flex; align-items: center; gap: 8px; }
.explainer summary::-webkit-details-marker { display: none; }
.explainer summary::before { content: '▸'; color: var(--muted); transition: transform .15s; }
.explainer[open] summary::before { transform: rotate(90deg); }
.explainer summary:hover { color: var(--accent); }
.explainer summary:focus-visible { outline: 2px solid var(--accent); outline-offset: -2px; border-radius: var(--radius); }
.explainer-body { padding: 0 14px 12px; font-size: 14px; line-height: 1.5; }
.explainer-body p { margin: 6px 0; }
.explainer-table { border-collapse: collapse; margin: 8px 0; font-size: 14px; }
.explainer-table th, .explainer-table td { text-align: left; padding: 4px 12px 4px 0; border-bottom: 1px solid var(--line); }
.explainer-table th { color: var(--muted); font-weight: 500; font-size: 12px; }

.sync-out { margin-top: 12px; }
.qr { background: #fff; padding: 12px; border-radius: 12px; display: inline-block; }
.qr:empty { display: none; }
.qr img, .qr canvas { display: block; }