/* ===== Theme tokens ===== */
:root {
  --bg: #f6f7f9;
  --surface: #ffffff;
  --surface-2: #eef1f5;
  --text: #1a1d23;
  --text-dim: #5b6472;
  --border: #d9dee6;
  --accent: #2563eb;
  --accent-soft: #dbe6ff;
  --ok: #15803d;
  --ok-soft: #dcfce7;
  --ng: #b91c1c;
  --ng-soft: #fee2e2;
  --shadow: 0 1px 2px rgba(16,24,40,.06), 0 4px 12px rgba(16,24,40,.06);
  --radius: 12px;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #14161a;
    --surface: #1c1f25;
    --surface-2: #252a32;
    --text: #e8eaed;
    --text-dim: #9aa4b2;
    --border: #333944;
    --accent: #6699ff;
    --accent-soft: #1e2a45;
    --ok: #4ade80;
    --ok-soft: #14301f;
    --ng: #f87171;
    --ng-soft: #3a1b1b;
    --shadow: 0 1px 2px rgba(0,0,0,.3), 0 4px 12px rgba(0,0,0,.25);
  }
}
:root[data-theme="dark"] {
  --bg: #14161a; --surface: #1c1f25; --surface-2: #252a32;
  --text: #e8eaed; --text-dim: #9aa4b2; --border: #333944;
  --accent: #6699ff; --accent-soft: #1e2a45;
  --ok: #4ade80; --ok-soft: #14301f; --ng: #f87171; --ng-soft: #3a1b1b;
  --shadow: 0 1px 2px rgba(0,0,0,.3), 0 4px 12px rgba(0,0,0,.25);
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans JP", "Segoe UI", sans-serif;
  line-height: 1.7;
  -webkit-text-size-adjust: 100%;
}
.wrap { max-width: 760px; margin: 0 auto; padding: 16px 16px 64px; }

/* ===== Header ===== */
header {
  display: flex; align-items: center; gap: 12px;
  padding: 12px 0 16px; flex-wrap: wrap;
}
header h1 { font-size: 1.05rem; margin: 0; letter-spacing: .01em; }
header .sub { color: var(--text-dim); font-size: .8rem; }
header .spacer { flex: 1; }

/* ===== Tabs ===== */
nav.tabs { display: flex; gap: 4px; background: var(--surface-2); padding: 4px; border-radius: 10px; margin-bottom: 20px; }
nav.tabs button {
  flex: 1; border: 0; background: transparent; color: var(--text-dim);
  padding: 9px 8px; border-radius: 7px; font-size: .88rem; cursor: pointer;
  font-family: inherit; font-weight: 500; transition: background .12s, color .12s;
}
nav.tabs button:hover { color: var(--text); }
nav.tabs button[aria-selected="true"] { background: var(--surface); color: var(--text); box-shadow: var(--shadow); }

/* ===== 出題レベル ===== */
.levelbar {
  display: flex; align-items: center; gap: 12px;
  margin: -8px 0 16px; flex-wrap: wrap;
}
.levelbar-label { font-size: .78rem; color: var(--text-dim); white-space: nowrap; }
.chips { display: flex; gap: 6px; flex-wrap: wrap; }
.chip {
  display: inline-flex; align-items: center; gap: 7px;
  border: 1px solid var(--border); background: var(--surface); color: var(--text-dim);
  border-radius: 99px; padding: 5px 12px; cursor: pointer;
  font-size: .8rem; font-family: inherit; font-weight: 500;
  transition: background .12s, border-color .12s, color .12s;
}
.chip:hover { border-color: var(--accent); }
.chip .chip-n {
  font-size: .68rem; font-variant-numeric: tabular-nums;
  background: var(--surface-2); border-radius: 99px; padding: 0 6px;
}
.chip.on { background: var(--accent-soft); border-color: var(--accent); color: var(--text); font-weight: 600; }
.chip.on .chip-n { background: var(--accent); color: #fff; }

/* レベル表示 */
.lvtag {
  display: inline-grid; place-items: center; min-width: 20px; height: 18px;
  padding: 0 5px; border-radius: 5px; font-size: .68rem; font-weight: 700;
  background: var(--surface-2); color: var(--text-dim); white-space: nowrap;
}
.lvtag.lv1 { background: var(--ok-soft); color: var(--ok); }
.lvtag.lv2 { background: var(--accent-soft); color: var(--accent); }
.lvtag.lv3 { background: var(--ng-soft); color: var(--ng); }

/* ===== Card ===== */
.card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 22px; box-shadow: var(--shadow);
}
.card + .card, .grid + .card { margin-top: 14px; }

/* ===== Quiz ===== */
.passage {
  background: var(--surface-2); border-radius: 10px; padding: 16px 18px;
  font-size: 1rem; line-height: 1.9; margin-bottom: 20px;
  font-family: Georgia, "Times New Roman", serif;
}
.passage .target { color: var(--accent); font-weight: 700; text-decoration: underline; text-underline-offset: 3px; }
.stem { font-size: .95rem; margin-bottom: 14px; }
.stem b { font-family: Georgia, serif; }

.choices { display: grid; gap: 8px; }
.choice {
  display: flex; align-items: center; gap: 12px; width: 100%; text-align: left;
  background: var(--surface); color: var(--text);
  border: 1px solid var(--border); border-radius: 10px;
  padding: 12px 14px; font-size: .95rem; font-family: inherit;
  cursor: pointer; transition: border-color .12s, background .12s;
}
.choice:hover:not(:disabled) { border-color: var(--accent); background: var(--accent-soft); }
.choice:disabled { cursor: default; }
.choice .key {
  flex: none; width: 24px; height: 24px; border-radius: 6px;
  background: var(--surface-2); color: var(--text-dim);
  display: grid; place-items: center; font-size: .78rem; font-weight: 600;
}
.choice.correct { border-color: var(--ok); background: var(--ok-soft); }
.choice.correct .key { background: var(--ok); color: #fff; }
.choice.wrong { border-color: var(--ng); background: var(--ng-soft); }
.choice.wrong .key { background: var(--ng); color: #fff; }

.feedback { margin-top: 18px; padding-top: 18px; border-top: 1px solid var(--border); }
.feedback .verdict { font-weight: 700; font-size: .95rem; margin-bottom: 12px; }
.feedback .verdict.ok { color: var(--ok); }
.feedback .verdict.ng { color: var(--ng); }

/* ===== 解説 ===== */
.expl-head {
  display: flex; align-items: baseline; gap: 10px; flex-wrap: wrap;
  padding-bottom: 12px; margin-bottom: 4px; border-bottom: 1px solid var(--border);
}
.expl-head .hw { font-family: Georgia, serif; font-size: 1.25rem; font-weight: 700; }
.expl-head .hw-pos {
  font-size: .7rem; color: var(--text-dim);
  background: var(--surface-2); border-radius: 99px; padding: 1px 8px;
}
.expl-head .hw-ja { font-size: .95rem; font-weight: 600; }
.expl-head .hw-syn { font-family: Georgia, serif; color: var(--accent); font-size: .88rem; }

/* ===== 再生ボタン ===== */
.spk {
  border: 1px solid var(--border); background: var(--surface);
  border-radius: 7px; padding: 1px 6px; cursor: pointer;
  font-size: .8rem; line-height: 1.5; color: var(--text);
  transition: background .12s, border-color .12s, transform .08s;
}
.spk:hover { background: var(--accent-soft); border-color: var(--accent); }
.spk:active { transform: scale(.92); }
.spk-lg { font-size: 1rem; padding: 3px 10px; }

.flash .word-line { display: flex; align-items: center; justify-content: center; gap: 12px; }

.expl-sec { margin-top: 16px; }
.expl-sec h4 {
  margin: 0 0 6px; font-size: .74rem; font-weight: 600;
  color: var(--text-dim); letter-spacing: .06em;
  display: flex; align-items: center; gap: 8px;
}
.expl-sec p { margin: 0; font-size: .9rem; }
.expl-sec .ex-en { font-family: Georgia, serif; line-height: 1.8; }
.expl-sec .ex-en .target { color: var(--accent); font-weight: 700; }
.expl-sec .ex-ja { margin-top: 4px; color: var(--text-dim); }

.opts { list-style: none; margin: 0; padding: 0; display: grid; gap: 5px; }
.opts li {
  display: flex; align-items: baseline; gap: 8px; flex-wrap: wrap;
  font-size: .88rem; padding: 7px 11px;
  border-radius: 8px; background: var(--surface-2);
  border-left: 3px solid transparent;
}
.opts li.is-ok { background: var(--ok-soft); border-left-color: var(--ok); }
.opts li.is-ng { background: var(--ng-soft); border-left-color: var(--ng); }
.opts .opt-en { font-family: Georgia, serif; font-weight: 700; }
.opts .opt-ja { color: var(--text-dim); font-size: .84rem; }
.opts .tag {
  margin-left: auto; font-size: .68rem; font-weight: 600;
  padding: 1px 7px; border-radius: 99px; white-space: nowrap;
}
.opts .tag.ok { background: var(--ok); color: #fff; }
.opts .tag.ng { background: var(--ng); color: #fff; }

.coll { list-style: none; margin: 0; padding: 0; display: grid; gap: 3px; font-size: .88rem; }
.coll li { padding-left: 14px; position: relative; }
.coll li::before { content: "▸"; position: absolute; left: 0; color: var(--text-dim); font-size: .7em; top: .35em; }

/* ===== Flashcard ===== */
.flash { text-align: center; padding: 34px 22px; }
.flash .word { font-size: 2rem; font-family: Georgia, serif; font-weight: 700; letter-spacing: .01em; }
.flash .pos { color: var(--text-dim); font-size: .82rem; margin-top: 4px; }
.flash .back { margin-top: 22px; padding-top: 22px; border-top: 1px dashed var(--border); }
.flash .ja { font-size: 1.15rem; font-weight: 600; }
.flash .syn { color: var(--accent); font-size: .95rem; margin-top: 6px; font-family: Georgia, serif; }
.flash .expl { text-align: left; margin-top: 4px; }

/* ===== Buttons ===== */
.row { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 18px; }
button.btn {
  border: 1px solid var(--border); background: var(--surface); color: var(--text);
  padding: 9px 16px; border-radius: 9px; cursor: pointer;
  font-size: .88rem; font-family: inherit; font-weight: 500; transition: background .12s, border-color .12s;
}
button.btn:hover { background: var(--surface-2); }
button.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
button.btn.primary:hover { filter: brightness(1.08); }
button.btn.grow { flex: 1; }
button.btn.ok { border-color: var(--ok); color: var(--ok); }
button.btn.ng { border-color: var(--ng); color: var(--ng); }
button.btn:disabled { opacity: .45; cursor: default; }
kbd {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: .72em;
  background: var(--surface-2); border: 1px solid var(--border);
  border-radius: 4px; padding: 1px 5px; color: var(--text-dim);
}

/* ===== ラジオ ===== */
.radio-choices { list-style: none; margin: 0; padding: 0; display: grid; gap: 7px; }
.radio-choices li {
  display: flex; align-items: center; gap: 12px;
  border: 1px solid var(--border); border-radius: 10px;
  padding: 11px 14px; font-size: .95rem;
  transition: border-color .15s, background .15s, transform .15s;
}
.radio-choices .key {
  flex: none; width: 24px; height: 24px; border-radius: 6px;
  background: var(--surface-2); color: var(--text-dim);
  display: grid; place-items: center; font-size: .78rem; font-weight: 600;
}
.radio-choices li.reading {
  border-color: var(--accent); background: var(--accent-soft); transform: translateX(3px);
}
.radio-choices li.reading .key { background: var(--accent); color: #fff; }
.radio-choices li.picked { border-color: var(--text-dim); }
.radio-choices li.picked .key { background: var(--text-dim); color: var(--surface); }
.radio-choices li.is-ok { border-color: var(--ok); background: var(--ok-soft); }
.radio-choices li.is-ok .key { background: var(--ok); color: #fff; }
.radio-choices li.is-ng { border-color: var(--ng); background: var(--ng-soft); }
.radio-choices li.is-ng .key { background: var(--ng); color: #fff; }

.radio-answer { margin-top: 18px; padding-top: 16px; border-top: 1px solid var(--border); }
.radio-answer-head {
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
  font-size: .95rem; margin-bottom: 6px;
}
.radio-answer-head b { font-family: Georgia, serif; color: var(--accent); }
.radio-answer-head .tag {
  font-size: .68rem; font-weight: 600; padding: 1px 8px; border-radius: 99px;
}
.radio-answer-head .tag.ok { background: var(--ok); color: #fff; }
.radio-answer-head .tag.ng { background: var(--ng); color: #fff; }
.radio-answer-ja { font-size: .88rem; color: var(--text-dim); }

/* ===== Progress ===== */
.progressbar { height: 6px; background: var(--surface-2); border-radius: 99px; overflow: hidden; margin-bottom: 18px; }
.progressbar > i { display: block; height: 100%; width: 0; background: var(--accent); transition: width .25s; }
.meta { display: flex; justify-content: space-between; font-size: .8rem; color: var(--text-dim); margin-bottom: 8px; }

/* ===== Stats ===== */
/* ===== 設定 ===== */
.settings {
  display: grid; grid-template-columns: auto 1fr;
  align-items: center; gap: 10px 14px; margin-bottom: 4px;
}
.settings label { font-size: .84rem; color: var(--text-dim); white-space: nowrap; }
.settings select { width: 100%; }

.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 12px; }
.stat { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; }
.stat .n { font-size: 1.7rem; font-weight: 700; line-height: 1.2; }
.stat .l { font-size: .78rem; color: var(--text-dim); margin-top: 2px; }
.boxes { display: grid; gap: 6px; margin-top: 6px; }
.boxrow { display: grid; grid-template-columns: 112px 1fr 44px; align-items: center; gap: 10px; font-size: .82rem; }
.boxrow .bar { height: 18px; background: var(--surface-2); border-radius: 5px; overflow: hidden; }
.boxrow .bar > i { display: block; height: 100%; background: var(--accent); }
.boxrow > span:first-child { white-space: nowrap; }
.boxrow .c { text-align: right; color: var(--text-dim); font-variant-numeric: tabular-nums; }

/* ===== List ===== */
.tools { display: flex; gap: 8px; margin-bottom: 14px; flex-wrap: wrap; }
input[type="search"], select {
  border: 1px solid var(--border); background: var(--surface); color: var(--text);
  border-radius: 9px; padding: 9px 12px; font-size: .88rem; font-family: inherit;
}
input[type="search"] { flex: 1; min-width: 160px; }
.tablewrap { overflow-x: auto; border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); }
table { border-collapse: collapse; width: 100%; font-size: .88rem; }
th, td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--border); vertical-align: top; }
th { font-size: .76rem; color: var(--text-dim); font-weight: 600; white-space: nowrap; background: var(--surface-2); position: sticky; top: 0; }
tr:last-child td { border-bottom: 0; }
td.w { font-family: Georgia, serif; font-weight: 700; white-space: nowrap; }
td.w .spk { margin-left: 8px; opacity: .45; }
td.pos { white-space: nowrap; }
tr.wordrow:hover td.w .spk, tr.wordrow.open td.w .spk { opacity: 1; }
td.syn { color: var(--accent); font-family: Georgia, serif; white-space: nowrap; }
.badge { display: inline-block; font-size: .7rem; padding: 1px 7px; border-radius: 99px; background: var(--surface-2); color: var(--text-dim); white-space: nowrap; }
.badge.b5 { background: var(--ok-soft); color: var(--ok); }
.badge.b0 { background: var(--surface-2); }

tr.wordrow { cursor: pointer; }
tr.wordrow:hover > td { background: var(--surface-2); }
tr.wordrow.open > td { background: var(--accent-soft); }
tr.detailrow > td { background: var(--surface-2); padding: 4px 16px 18px; }

.empty { text-align: center; color: var(--text-dim); padding: 48px 20px; font-size: .92rem; }
.hint { font-size: .78rem; color: var(--text-dim); margin-top: 12px; }
.hidden { display: none !important; }

/* ===== Narrow screens ===== */
@media (max-width: 480px) {
  .wrap { padding: 12px 12px 56px; }
  header { flex-wrap: nowrap; gap: 8px; }
  header > div:first-child { min-width: 0; flex: 1; }
  header .spacer { display: none; } /* 見出し側が flex:1 なので余白は不要 */
  header h1 { font-size: .98rem; }
  nav.tabs button { font-size: .74rem; padding: 9px 2px; white-space: nowrap; }
  nav.tabs { gap: 2px; padding: 3px; }
  .card { padding: 16px; }
  .levelbar { gap: 6px; }
  .levelbar-label { width: 100%; }
  .chip { padding: 5px 10px; font-size: .76rem; }
  .passage { padding: 14px; font-size: .95rem; }
  .expl-head .hw { font-size: 1.1rem; }
  .opts li { gap: 4px 8px; }
  .opts .tag { margin-left: 0; }
  tr.detailrow > td { padding: 4px 12px 16px; }
  .settings { grid-template-columns: 1fr; gap: 4px; }
  .settings label { margin-top: 8px; }
  .flash { padding: 28px 16px; }
  .flash .word { font-size: 1.6rem; }
}