:root {
  --bg: #f6f4ef; --card: #ffffff; --ink: #2b2724; --muted: #7c736b;
  --accent: #5a4a9e; --accent2: #2f6b5e; --line: #e7e1d8;
  --ok: #2f8f5b; --bad: #c0392b; --note: #fbf3e6; --noteline: #e6c79a;
  --shadow: 0 1px 3px rgba(0,0,0,.06), 0 6px 18px rgba(0,0,0,.05);
}
* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  background: var(--bg); color: var(--ink);
  font-family: "Noto Sans TC", "PingFang TC", "Microsoft JhengHei", system-ui, sans-serif;
  line-height: 1.7; -webkit-font-smoothing: antialiased;
}
#topbar {
  position: sticky; top: 0; z-index: 10; display: flex; align-items: center; gap: 12px;
  padding: 12px 16px; background: rgba(246,244,239,.92); backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.brand { font-weight: 700; letter-spacing: .5px; }
.spacer { flex: 1; }
.back { border: 0; background: none; color: var(--accent); font-size: 15px; cursor: pointer; padding: 4px 6px; }
.pill { font-size: 12px; color: var(--muted); background: var(--card); border: 1px solid var(--line); padding: 4px 10px; border-radius: 999px; }
main { max-width: 760px; margin: 0 auto; padding: 20px 16px 64px; }
#foot { max-width: 760px; margin: 0 auto; padding: 20px 16px 48px; color: var(--muted); font-size: 12px; text-align: center; }
.loading { color: var(--muted); padding: 40px 0; text-align: center; }

.hero h1 { font-size: 24px; margin: 6px 0 2px; }
.hero p { color: var(--muted); margin: 0 0 18px; }

.track-head { margin: 26px 0 10px; display: flex; align-items: baseline; gap: 10px; }
.track-head h2 { font-size: 16px; margin: 0; }
.track-head .sub { color: var(--muted); font-size: 13px; }

.daily-top { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin: 2px 0 12px; }
.daily-date { color: var(--muted); font-size: 13px; }
.archive-link { color: var(--accent2); font-size: 13px; text-decoration: none; white-space: nowrap; }
.archive-link:hover { text-decoration: underline; }
.arch-day { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 12px 14px; margin: 8px 0; box-shadow: var(--shadow); }
.arch-date { font-size: 12px; color: var(--muted); margin-bottom: 6px; }
.arch-row { display: flex; align-items: center; gap: 8px; padding: 4px 0; flex-wrap: wrap; }
.arch-tag { font-size: 11px; color: #fff; border-radius: 6px; padding: 1px 7px; flex: none; }
.arch-tag.w { background: var(--accent); }
.arch-tag.s { background: var(--accent2); }
.arch-tx { font-weight: 600; color: var(--ink); }
.arch-zh { color: var(--muted); font-size: 13px; flex: 1; min-width: 80px; }

.daily { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin: 4px 0 22px; }
@media (max-width: 560px) { .daily { grid-template-columns: 1fr; } }
.daily-card { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 14px 16px; box-shadow: var(--shadow); display: flex; flex-direction: column; }
.daily-h { display: inline-flex; align-items: center; gap: 6px; align-self: flex-start;
  font-size: 11px; letter-spacing: 1px; color: #fff; padding: 3px 5px 3px 10px; border-radius: 999px; margin-bottom: 10px; }
.daily-h .play { background: rgba(255,255,255,.92); width: 20px; height: 20px; font-size: 11px; }
.daily-h .play:hover { background: #fff; }
.dc-word .daily-h { background: var(--accent); }
.dc-sent .daily-h { background: var(--accent2); }
.dterm { display: flex; align-items: center; gap: 8px; font-size: 19px; font-weight: 700; line-height: 1.4; }
.dterm-tx { flex: 1; }
.dc-word .dterm-tx { color: var(--accent); }
.dc-sent .dterm-tx { color: var(--accent2); }
.dgloss { margin-top: 6px; font-size: 14.5px; color: var(--ink); }
.dgloss .pos { color: var(--muted); font-size: 13px; }
.play { border: 0; background: #efe9df; color: var(--ink); border-radius: 999px; width: 32px; height: 32px;
  flex: none; font-size: 15px; cursor: pointer; line-height: 1; padding: 0; }
.play:hover { background: #e3dac8; }
.play:active { transform: scale(.92); }

.pick-prompt { color: var(--muted); font-size: 14px; margin: 6px 0 14px; }
.topabout { color: var(--muted); font-size: 13px; text-decoration: none; padding: 4px 8px; border: 1px solid var(--line); border-radius: 999px; white-space: nowrap; }
.topabout:hover { color: var(--accent); border-color: var(--accent); }
.track-choice {
  display: block; text-decoration: none; color: #fff; cursor: pointer;
  border-radius: 18px; padding: 22px 20px; margin: 14px 0; box-shadow: var(--shadow);
  transition: transform .08s ease, box-shadow .12s ease;
}
.track-choice:hover { transform: translateY(-2px); box-shadow: 0 4px 10px rgba(0,0,0,.1), 0 14px 34px rgba(0,0,0,.1); }
.track-phonology { background: linear-gradient(135deg, #3a4f8a, #5c79c4); }
.track-morphology { background: linear-gradient(135deg, #b5562d, #d07a45); }
.track-syntax { background: linear-gradient(135deg, #2f6b5e, #4a9a7e); }
.tc-title { font-size: 22px; font-weight: 700; }
.tc-sub { font-size: 14px; opacity: .92; margin-top: 4px; }
.track-choice .bar { background: rgba(255,255,255,.3); margin-top: 16px; }
.track-choice .bar > i { background: #fff; }
.tc-meta { font-size: 12.5px; opacity: .9; margin-top: 8px; }

.unit {
  display: block; background: var(--card); border: 1px solid var(--line); border-radius: 14px;
  padding: 16px; margin: 10px 0; box-shadow: var(--shadow); cursor: pointer; text-decoration: none; color: inherit;
  transition: transform .08s ease, box-shadow .12s ease;
}
.unit:hover { transform: translateY(-1px); box-shadow: 0 2px 6px rgba(0,0,0,.08), 0 10px 26px rgba(0,0,0,.07); }
.unit.locked { opacity: .55; cursor: default; }
.unit .row { display: flex; align-items: center; gap: 10px; }
.unit .title { font-weight: 600; font-size: 16px; }
.unit .ch { display: inline-block; font-size: 11px; font-weight: 600; color: var(--accent); background: #f3e7df; border-radius: 6px; padding: 1px 7px; margin-right: 8px; vertical-align: middle; }
.unit .summary { color: var(--muted); font-size: 13.5px; margin-top: 4px; }
.badge { font-size: 11px; padding: 2px 8px; border-radius: 999px; border: 1px solid var(--line); color: var(--muted); white-space: nowrap; }
.badge.done { color: #fff; background: var(--accent2); border-color: var(--accent2); }
.badge.soon { background: #efe9df; }
.bar { height: 6px; background: #eee7dc; border-radius: 999px; margin-top: 12px; overflow: hidden; }
.bar > i { display: block; height: 100%; background: var(--accent); border-radius: 999px; }

.lesson-list { margin-top: 8px; }
.lesson-item { display: flex; align-items: center; gap: 12px; background: var(--card); border: 1px solid var(--line);
  border-radius: 12px; padding: 14px 16px; margin: 8px 0; cursor: pointer; box-shadow: var(--shadow); }
.lesson-item .n { width: 26px; height: 26px; flex: none; border-radius: 50%; background: var(--accent); color: #fff;
  display: grid; place-items: center; font-size: 13px; font-weight: 700; }
.lesson-item.done .n { background: var(--ok); }
.lesson-item .t { flex: 1; font-weight: 500; }
.lesson-item .chev { color: var(--muted); }

.unit-title { font-size: 20px; margin: 6px 0 2px; }
.unit-sub { color: var(--muted); margin: 0 0 8px; font-size: 14px; }

article h2.l-title { font-size: 21px; margin: 4px 0 14px; }
article p { margin: 12px 0; }
article ul { margin: 12px 0; padding-left: 22px; }
article li { margin: 6px 0; }
.note { background: var(--note); border: 1px solid var(--noteline); border-left: 4px solid var(--accent);
  border-radius: 10px; padding: 12px 14px; margin: 16px 0; font-size: 14.5px; }
.note b { color: var(--accent); }
table.g { width: 100%; border-collapse: collapse; margin: 16px 0; font-size: 14px; background: var(--card);
  border: 1px solid var(--line); border-radius: 10px; overflow: hidden; }
table.g th { background: #efe9df; text-align: left; padding: 9px 12px; font-weight: 600; }
table.g td { padding: 9px 12px; border-top: 1px solid var(--line); vertical-align: top; }
.tr-word { font-family: "Iowan Old Style", Georgia, serif; }

.ex-head { margin: 22px 0 6px; font-size: 13px; letter-spacing: 1px; color: var(--muted); text-transform: uppercase; }
.ex { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 12px 14px; margin: 10px 0; box-shadow: var(--shadow); }
.ex .tr { font-size: 17px; font-weight: 600; color: var(--accent); }
.ex .gloss { font-size: 13px; color: var(--muted); margin-top: 3px; font-style: italic; }
.ex .zh { margin-top: 4px; }
.ex .en { font-size: 13px; color: var(--muted); margin-top: 2px; }
.ex .exnote { font-size: 13px; margin-top: 6px; background: var(--note); border-radius: 8px; padding: 6px 9px; }

.quiz { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 16px; margin: 12px 0; box-shadow: var(--shadow); }
.quiz .q { font-weight: 600; margin-bottom: 10px; }
.opt { display: block; width: 100%; text-align: left; background: #faf8f4; border: 1px solid var(--line);
  border-radius: 10px; padding: 11px 13px; margin: 7px 0; cursor: pointer; font: inherit; transition: background .1s; }
.opt:hover:not(:disabled) { background: #f1ece3; }
.opt.correct { background: #e4f4ea; border-color: var(--ok); color: #1d6b40; }
.opt.wrong { background: #fbe7e4; border-color: var(--bad); color: #9c2b1f; }
.opt:disabled { cursor: default; }
.explain { margin-top: 8px; font-size: 14px; color: var(--accent2); }

.feedback { margin-top: 24px; padding: 14px 16px; background: var(--card); border: 1px solid var(--line); border-radius: 14px; box-shadow: var(--shadow); }
.fb-q { font-size: 14px; color: var(--muted); margin-bottom: 10px; }
.fb-btns { display: flex; gap: 8px; }
.fb { flex: 1; border: 1px solid var(--line); background: #faf8f4; border-radius: 10px; padding: 10px; font: inherit; cursor: pointer; }
.fb:hover { background: #f1ece3; }
.fb.on { background: var(--accent); color: #fff; border-color: var(--accent); }
.fb-followup { margin-top: 12px; padding-top: 12px; border-top: 1px solid var(--line); }
.fu-msg { font-size: 14px; margin-bottom: 10px; color: var(--ink); }
.fu-btns { display: flex; gap: 8px; flex-wrap: wrap; }
.fu-btn { border: 0; border-radius: 10px; padding: 9px 14px; font: inherit; font-weight: 600; cursor: pointer; }
.fu-btn.primary { background: var(--accent); color: #fff; }
.fu-btn.ghost { background: var(--card); border: 1px solid var(--line); color: var(--ink); }

.ask { margin-top: 20px; padding: 16px; background: var(--note); border: 1px solid var(--noteline); border-radius: 14px; }
.ask-q { font-weight: 600; margin-bottom: 8px; color: var(--accent); }
.ask textarea { width: 100%; box-sizing: border-box; border: 1px solid var(--line); border-radius: 10px; padding: 10px; font: inherit; resize: vertical; }
.ask #askBtn { margin-top: 8px; }
.ask-answer { margin-top: 12px; padding: 12px 14px; background: var(--card); border: 1px solid var(--line); border-radius: 10px; white-space: pre-wrap; line-height: 1.7; }

.lesson-nav { display: flex; gap: 10px; margin-top: 26px; }
.btn { flex: 1; border: 0; border-radius: 12px; padding: 13px; font: inherit; font-weight: 600; cursor: pointer; }
.btn.primary { background: var(--accent); color: #fff; }
.btn.ghost { background: var(--card); border: 1px solid var(--line); color: var(--ink); }
.btn:disabled { opacity: .4; cursor: default; }

/* Mptgesa (AI tutor) chapter-jump buttons */
.ask-jump { margin-top:.6rem; display:flex; flex-wrap:wrap; gap:.4rem; align-items:center; }
.aj-q { font-size:.85rem; color:#5b5145; }
.aj-btn { font:inherit; font-size:.85rem; background:var(--accent); color:#fff; border:0;
          border-radius:8px; padding:.35rem .7rem; cursor:pointer; }
.aj-btn:hover { filter:brightness(0.92); }