/* Three Habits That Build Wealth — interactive lesson for working adults.

   A teacher drives this in a one-to-one or small-group session, usually on one
   laptop turned sideways or a shared screen. Design notes:

   - English leads and is the only thing on screen by default. Traditional
     Chinese sits behind a small 中 chip on every line, so the learner tries the
     English first and the safety net is one tap away. Instructions, task
     prompts and the contents list stay bilingual throughout — those are
     scaffolding, not comprehension practice.
   - Interactive parts look interactive: anything with a border and a hand
     cursor can be clicked. Nothing else moves.
   - Wrong answers wobble and stay open. There is no score, no streak and no
     progress bar; the teacher is the feedback, and the exercise is a reason to
     talk.
   - Light theme only. It is read side by side in a lit room, and the source
     PDF is the reference.
   - Text sizes are set for adults reading at arm's length on a shared screen,
     a size up from a personal document. */

:root {
  --paper: #f7f6f2;
  --card: #ffffff;
  --ink: #1c2430;
  --ink-soft: #566171;
  --ink-faint: #8b95a3;

  --navy: #1d3f6e;
  --navy-soft: #eaf0f8;
  --navy-line: #c2d3e7;

  --gold: #a1741a;
  --gold-soft: #fbf1da;
  --gold-line: #f2c14e;

  --good: #2c7a58;
  --good-soft: #e4f2ea;
  --good-line: #a8d6be;

  --line: #e3e0d8;
  --rule: #cdc8bc;

  --font-en: "Iowan Old Style", "Palatino Linotype", Palatino, Charter, Georgia, "Times New Roman", serif;
  --font-zh: "PingFang TC", "Heiti TC", "Noto Sans TC", "Microsoft JhengHei", "Hiragino Sans CNS", sans-serif;
  --font-ui: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;

  --bar-h: 54px;
  --measure: 46rem;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--bar-h) + 16px); }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-en);
  font-size: 18px;
  line-height: 1.6;
  -webkit-text-size-adjust: 100%;
}

/* ---------------- the Chinese layer ----------------

   Hidden everywhere by default. A line opens on its own when tapped; the 中文
   switch in the bar opens all of them at once, at which point the individual
   chips are just clutter and go away. */

.zh {
  display: none;
  font-family: var(--font-zh);
  font-size: 0.82em;
  line-height: 1.7;
  color: var(--ink-soft);
  letter-spacing: .01em;
}

.open .zh,
body.zh-all .zh { display: block; }

.zh-chip {
  font-family: var(--font-zh);
  font-size: 11px;
  line-height: 1;
  vertical-align: 2px;
  margin-left: 6px;
  padding: 3px 5px;
  color: var(--ink-faint);
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 5px;
  cursor: pointer;
  transition: color .12s, border-color .12s, background .12s;
}
.zh-chip:hover { color: var(--navy); border-color: var(--navy-line); background: var(--navy-soft); }
.open > .zh-chip,
.open .en > .zh-chip { opacity: .35; }
body.zh-all .zh-chip { display: none; }

/* Lines the learner is not being tested on stay bilingual at all times. Two
   groups qualify: scaffolding that only helps if it is understood (hints, task
   prompts, navigation), and anything already sitting behind a deliberate reveal
   — a flipped phrase card, an opened "useful language" list — where a second
   tap would only be in the way. */
.hint-zh, .source .zh, .prompt .zh, .toc .t .zh, .why .zh,
.starters .zh, .frames .zh, .tick-t .zh { display: block; }

.pair[data-zh] { cursor: pointer; }
.pair p { margin: 0; }
.pair .zh { margin-top: 4px; }

.skip { position: absolute; left: -9999px; }
.skip:focus {
  left: 12px; top: 12px; z-index: 40;
  background: var(--card); padding: 10px 16px; border-radius: 8px;
}

:focus-visible { outline: 2px solid var(--navy); outline-offset: 2px; }

/* ---------------- top bar ---------------- */

.bar {
  position: sticky;
  top: 0;
  z-index: 30;
  height: var(--bar-h);
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 0 16px;
  background: rgba(247, 246, 242, .93);
  backdrop-filter: saturate(1.6) blur(10px);
  border-bottom: 1px solid var(--line);
}

.bar-title {
  flex: 1;
  margin: 0;
  min-width: 0;
  font-size: 15px;
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.bar-title span {
  font-family: var(--font-zh);
  font-size: 13px;
  font-weight: 400;
  color: var(--ink-faint);
  margin-left: 8px;
}

.bar-btn {
  flex: none;
  font-family: var(--font-ui);
  font-size: 13px;
  color: var(--navy);
  background: transparent;
  border: 1px solid var(--navy-line);
  border-radius: 7px;
  padding: 6px 11px;
  cursor: pointer;
}
.bar-btn:hover { background: var(--navy-soft); }
.bar-btn-quiet { color: var(--ink-soft); border-color: var(--line); font-size: 15px; padding: 4px 9px; }
.bar-btn-zh { font-family: var(--font-zh); }
.bar-btn-zh[aria-pressed="true"] { background: var(--navy); border-color: var(--navy); color: #fff; }

@media (min-width: 900px) { #navToggle { display: none; } }

/* ---------------- shell + contents ---------------- */

.shell {
  display: grid;
  grid-template-columns: 1fr;
  max-width: 76rem;
  margin: 0 auto;
  padding: 0 20px;
}

@media (min-width: 900px) {
  .shell { grid-template-columns: 15rem minmax(0, 1fr); gap: 44px; padding: 0 28px; }
}

.toc { font-family: var(--font-ui); }

@media (min-width: 900px) {
  .toc {
    position: sticky;
    top: var(--bar-h);
    max-height: calc(100vh - var(--bar-h));
    overflow-y: auto;
    padding: 30px 0 40px;
    scrollbar-width: thin;
  }
}

.toc-head {
  margin: 0 0 10px;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

.toc ul { list-style: none; margin: 0; padding: 0; }

.toc a {
  display: grid;
  grid-template-columns: 1.4rem 1fr;
  gap: 8px;
  padding: 8px 10px 8px 6px;
  border-radius: 7px;
  text-decoration: none;
  color: var(--ink-soft);
  border-left: 2px solid transparent;
}
.toc a:hover { background: var(--navy-soft); color: var(--ink); }
.toc a .n {
  font-size: 12px;
  font-variant-numeric: tabular-nums;
  color: var(--ink-faint);
  text-align: right;
  padding-top: 3px;
}
.toc a .t .en { display: block; font-size: 13.5px; line-height: 1.35; }
.toc a .t .zh { font-size: 11.5px; color: var(--ink-faint); }
.toc a.here {
  background: var(--navy-soft);
  border-left-color: var(--navy);
  color: var(--navy);
}
.toc a.here .n, .toc a.here .t .zh { color: var(--navy); }
.toc a.here .t .en { font-weight: 600; }

@media (max-width: 899px) {
  #nav {
    position: fixed;
    top: var(--bar-h);
    left: 0; right: 0;
    z-index: 25;
    max-height: min(70vh, 30rem);
    overflow-y: auto;
    background: var(--card);
    border-bottom: 1px solid var(--line);
    box-shadow: 0 12px 24px rgba(28, 36, 48, .12);
    padding: 14px 18px 18px;
    display: none;
  }
  body.nav-open #nav { display: block; }
  body.nav-open .nav-scrim {
    display: block;
    position: fixed;
    inset: var(--bar-h) 0 0;
    z-index: 20;
    background: rgba(28, 36, 48, .25);
  }
}

/* ---------------- cover ---------------- */

main { max-width: var(--measure); padding-bottom: 6rem; }

.cover { padding: 40px 0 10px; }

/* Set for the Chinese kicker: the tracking that flatters small uppercase Latin
   crowds Chinese glyphs, which need a size up and a little more air. */
.kicker {
  margin: 0 0 14px;
  font-family: var(--font-zh);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .16em;
  color: var(--gold);
}

.cover h1 { margin: 0 0 24px; font-size: 2.2rem; line-height: 1.18; font-weight: 600; }
/* Inline so the 中 chip trails the last word rather than dropping a line. */
.cover h1 .en { display: inline; }
.cover h1 .zh { font-size: .95rem; font-weight: 400; margin-top: 8px; }

.cover-intro { margin-bottom: 26px; font-size: 1.06rem; }

.goals {
  padding: 20px 22px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
}
.goals-intro { font-family: var(--font-ui); font-size: .88rem; color: var(--ink-soft); }
.goals ul { margin: 12px 0 0; padding-left: 1.1rem; }
.goals li { margin: 0 0 8px; font-size: .98rem; }
.goals li .zh { font-size: .8rem; }

.source {
  margin: 22px 0 0;
  font-family: var(--font-ui);
  font-size: .76rem;
  line-height: 1.6;
  color: var(--ink-faint);
}
.source .zh { font-size: .95em; color: var(--ink-faint); margin-top: 2px; }

/* ---------------- photographs ----------------

   One picture opens the lesson and one opens each habit. They are illustration,
   not content, so they stay quiet: a fixed 16:9 band the text column can sit
   against, no shadow, and a hairline that matches every other card on the page.
   Each file is 16:9 already; `object-position` (set per photo in content.js)
   decides what survives the tighter crop on a narrow screen. */

.photo { margin: 0 0 26px; }

.photo img {
  display: block;
  width: 100%;
  /* The width/height attributes reserve the space before the file arrives, but
     they also set a used height — `auto` hands control back to aspect-ratio. */
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: var(--navy-soft);   /* holds the space while the file loads */
}

.photo figcaption {
  margin-top: 7px;
  font-family: var(--font-ui);
  font-size: .7rem;
  letter-spacing: .02em;
  color: var(--ink-faint);
  text-align: right;
}

/* On the cover the picture sits between the title and the standfirst, and can
   run a little shallower — the goals card below it is the thing to reach. */
.photo-hero { margin: 0 0 24px; }
.photo-hero img { aspect-ratio: 21 / 9; }

@media (max-width: 620px) {
  .photo img, .photo-hero img { aspect-ratio: 3 / 2; }
}

/* ---------------- steps ---------------- */

.step { padding-top: 46px; }

.step-head {
  display: grid;
  grid-template-columns: 2.4rem 1fr;
  gap: 14px;
  align-items: start;
  margin: 0 0 22px;
  padding-bottom: 14px;
  border-bottom: 2px solid var(--gold-line);
  font-size: 1.55rem;
  font-weight: 600;
  line-height: 1.25;
}
.step-head .n {
  font-family: var(--font-ui);
  font-size: 1rem;
  font-weight: 700;
  color: #fff;
  background: var(--navy);
  border-radius: 8px;
  text-align: center;
  padding: 4px 0;
  margin-top: 5px;
}
.step-head .titles .en { display: inline; }
.step-head .titles .zh { font-size: .95rem; font-weight: 400; margin-top: 4px; }

.lead {
  margin: 0 0 24px;
  font-size: 1.1rem;
  font-style: italic;
  color: var(--ink-soft);
}
.lead .zh { font-style: normal; }

/* ---------------- quote ---------------- */

.quote {
  margin: 0 0 26px;
  padding: 4px 0 4px 20px;
  border-left: 4px solid var(--gold-line);
}
.quote blockquote { margin: 0; font-size: 1.22rem; line-height: 1.5; }
.quote blockquote p { margin: 0; }
.quote .zh { font-size: .82rem; margin-top: 8px; font-style: normal; }
.quote figcaption {
  margin-top: 8px;
  font-family: var(--font-ui);
  font-size: .78rem;
  color: var(--ink-faint);
}

.summary { margin: 0 0 20px; }

/* ---------------- note ---------------- */

.note {
  margin: 26px 0;
  padding: 18px 22px;
  background: var(--gold-soft);
  border: 1px solid #ecdcb4;
  border-radius: 12px;
}
.note h4 {
  margin: 0 0 8px;
  font-family: var(--font-ui);
  font-size: .84rem;
  font-weight: 700;
  letter-spacing: .04em;
  text-transform: uppercase;
  color: var(--gold);
}
.note h4 .en { display: inline; }
.note h4 .zh { text-transform: none; letter-spacing: 0; margin-top: 4px; }
.note p { font-size: .96rem; }

/* ---------------- speak buttons ---------------- */

.say {
  font-size: .78em;
  line-height: 1;
  margin-left: 7px;
  padding: 3px 5px;
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 6px;
  cursor: pointer;
  opacity: .55;
  transition: opacity .12s, border-color .12s;
}
.say:hover { opacity: 1; border-color: var(--navy-line); }
.say-quiet { border-color: transparent; }

/* ---------------- section labels ---------------- */

.label {
  margin: 32px 0 12px;
  font-family: var(--font-ui);
  font-size: .8rem;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--navy);
}
.label .en { display: inline; }
.label .zh {
  text-transform: none;
  letter-spacing: 0;
  font-size: .82rem;
  font-weight: 400;
  margin-top: 4px;
}

.hint {
  margin: 0 0 14px;
  font-family: var(--font-ui);
  font-size: .84rem;
  color: var(--ink-faint);
}
.hint-zh { font-family: var(--font-zh); font-size: .95em; margin-top: 2px; }

/* ---------------- collocation cards ---------------- */

.cards {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(15rem, 1fr));
  gap: 10px;
  /* Opening one card should not stretch the others sharing its row. */
  align-items: start;
}

.card {
  padding: 12px 14px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  cursor: pointer;
  transition: border-color .12s, box-shadow .12s;
}
.card:hover { border-color: var(--navy-line); box-shadow: 0 2px 8px rgba(28, 36, 48, .06); }
.card-en { margin: 0; font-size: 1rem; font-weight: 600; }
.card-back { display: none; margin-top: 8px; padding-top: 8px; border-top: 1px dashed var(--line); }
.card.open { border-color: var(--navy-line); background: var(--navy-soft); }
.card.open .card-back { display: block; }
.card-zh { margin: 0; font-family: var(--font-zh); font-size: .84rem; color: var(--ink-soft); }
.card-eg { margin: 6px 0 0; font-size: .9rem; font-style: italic; color: var(--ink-soft); }
.card-eg-zh {
  margin: 3px 0 0;
  font-family: var(--font-zh);
  font-size: .78rem;
  line-height: 1.65;
  color: var(--ink-faint);
}

/* ---------------- activities ---------------- */

.activity { margin: 0 0 10px; }

.chip {
  font-family: var(--font-en);
  font-size: .95rem;
  color: var(--ink);
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 9px;
  padding: 8px 13px;
  cursor: pointer;
  text-align: left;
  transition: border-color .12s, background .12s, color .12s;
}
.chip:hover { border-color: var(--navy-line); background: var(--navy-soft); }
.chip.picked { border-color: var(--navy); background: var(--navy-soft); color: var(--navy); font-weight: 600; }
.chip.done {
  border-color: var(--good-line);
  background: var(--good-soft);
  color: var(--good);
  cursor: default;
}
.chip.out { opacity: .4; }

@keyframes wobble {
  0%, 100% { transform: translateX(0); }
  20% { transform: translateX(-5px); }
  45% { transform: translateX(4px); }
  70% { transform: translateX(-2px); }
}
.no { animation: wobble .4s ease; border-color: #d8a08a; }

/* matching */

.match-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.match .col { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; align-content: start; }
.match .chip { width: 100%; }
.match .col-b .chip { color: var(--ink-soft); }

.tally {
  margin: 12px 0 0;
  font-family: var(--font-ui);
  font-size: .8rem;
  color: var(--ink-faint);
  font-variant-numeric: tabular-nums;
}
.match.all-done .tally { color: var(--good); font-weight: 600; }

/* gap fill */

.gap {
  margin: 0 0 18px;
  padding: 14px 16px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
}
/* The number sits in its own narrow column so the sentence, and the Chinese
   under it, share one left edge. */
.gap-line { margin: 0 0 10px; }
.gap-line .en { display: grid; grid-template-columns: 1.6rem 1fr; }
.gap-line .zh { margin-top: 5px; padding-left: 1.6rem; }
.gap-n {
  font-family: var(--font-ui);
  font-size: .8rem;
  color: var(--ink-faint);
  padding-top: 5px;
}
.gap-text { font-size: 1rem; }

.slot {
  display: inline-block;
  min-width: 9rem;
  border-bottom: 2px solid var(--navy-line);
  text-align: center;
  color: var(--navy);
  font-weight: 600;
  line-height: 1.3;
}
.gap.solved .slot { border-bottom-color: var(--good); color: var(--good); }

.opts { list-style: none; margin: 0; padding: 0 0 0 1.6rem; display: flex; flex-wrap: wrap; gap: 8px; }
.gap.solved .opts { display: none; }

.why {
  display: none;
  margin: 10px 0 0 1.6rem;
  font-family: var(--font-ui);
  font-size: .84rem;
  color: var(--ink-soft);
}
.gap.solved .why { display: block; }
.why .zh { font-size: .95em; color: var(--ink-faint); margin-top: 2px; }

/* opinion poll */

.poll-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 16px;
  align-items: center;
  justify-content: space-between;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}
.poll-row .pair { flex: 1 1 18rem; }
.poll-btns { display: flex; gap: 6px; flex: none; }
.poll-btns .chip, .role-btns .chip {
  font-family: var(--font-ui);
  font-size: .82rem;
  padding: 5px 11px;
  text-align: center;
}
/* The Chinese rides under the label inside the button, so a two-word answer
   does not become two buttons wide. */
.chip em {
  display: block;
  font-family: var(--font-zh);
  font-style: normal;
  font-size: .72rem;
  line-height: 1.4;
  color: var(--ink-faint);
}
.chip.on { border-color: var(--navy); background: var(--navy); color: #fff; font-weight: 600; }
.chip.on em { color: rgba(255, 255, 255, .8); }

/* kitchen cabinet audit */

.roles {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(16rem, 1fr));
  gap: 12px;
  align-items: start;
}
.role {
  padding: 16px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
}
.role-icon { margin: 0 0 6px; font-size: 1.4rem; line-height: 1; }
.role-desc { margin-top: 6px; font-size: .9rem; color: var(--ink-soft); }
.role-btns { display: flex; gap: 6px; margin-top: 12px; }

/* discussion */

.discuss { margin-bottom: 8px; }
.ask {
  margin: 0 0 16px;
  padding: 16px 18px;
  background: var(--card);
  border: 1px solid var(--line);
  border-left: 3px solid var(--navy-line);
  border-radius: 10px;
}
.ask .en { font-size: 1.04rem; }

.reveal {
  margin-top: 12px;
  font-family: var(--font-ui);
  font-size: .78rem;
  letter-spacing: .02em;
  color: var(--ink-soft);
  background: transparent;
  border: 1px dashed var(--rule);
  border-radius: 7px;
  padding: 5px 10px;
  cursor: pointer;
}
.reveal:hover { color: var(--navy); border-color: var(--navy-line); }
.reveal[aria-expanded="true"] { color: var(--navy); border-style: solid; border-color: var(--navy-line); }

.starters { list-style: none; margin: 12px 0 0; padding: 0; }
.starters li {
  margin: 0 0 8px;
  padding: 8px 12px;
  background: var(--navy-soft);
  border-radius: 8px;
  font-size: .95rem;
  font-style: italic;
  color: var(--ink-soft);
}
.starters li .en, .frames li .en { display: block; }
.starters li .zh, .frames li .zh {
  margin-top: 4px;
  font-style: normal;
  font-size: .78rem;
  color: var(--ink-faint);
}

/* tasks */

.task {
  margin: 0 0 12px;
  padding: 20px 22px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
}
.task > .label { margin-top: 0; }
.task-how { margin-bottom: 14px; font-size: .98rem; }

.prompts { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
.prompt {
  width: 100%;
  text-align: left;
  font-family: var(--font-en);
  font-size: .98rem;
  color: var(--ink);
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 11px 14px;
  cursor: pointer;
}
.prompt:hover { border-color: var(--navy-line); background: var(--navy-soft); }
.prompt .en { display: block; }
.prompt .zh { font-size: .8rem; margin-top: 3px; }
.prompt.on { border-color: var(--navy); background: var(--navy-soft); }
.prompt.on .en { font-weight: 600; color: var(--navy); }

.checklist, .frames { margin-top: 20px; padding-top: 16px; border-top: 1px solid var(--line); }
.checklist-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 10px;
  margin: 0 0 10px;
  font-family: var(--font-ui);
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--ink-faint);
}
/* The Chinese belongs beside its English label, so it takes the free space and
   leaves the counter pinned to the right. */
.checklist-head em {
  margin-right: auto;
  font-family: var(--font-zh);
  font-style: normal;
  font-weight: 400;
  letter-spacing: 0;
  text-transform: none;
}
.count { font-weight: 400; letter-spacing: 0; text-transform: none; font-variant-numeric: tabular-nums; }

.checklist ul { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 8px; }
.tick {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  text-align: left;
  font-family: var(--font-en);
  font-size: .92rem;
  color: var(--ink-soft);
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 6px 13px 6px 9px;
  cursor: pointer;
}
.tick .box {
  width: 14px; height: 14px;
  border: 1.5px solid var(--rule);
  border-radius: 4px;
  flex: none;
}
.tick:hover { border-color: var(--navy-line); }
.tick.on { color: var(--good); border-color: var(--good-line); background: var(--good-soft); }
.tick.on .box { background: var(--good); border-color: var(--good); position: relative; }
.tick.on .box::after {
  content: "✓";
  position: absolute;
  inset: 0;
  color: #fff;
  font-size: 11px;
  line-height: 12px;
  text-align: center;
}

.frames ul { list-style: none; margin: 0; padding: 0; }
.frames li {
  margin: 0 0 8px;
  padding: 9px 13px;
  background: var(--paper);
  border-left: 3px solid var(--navy-line);
  border-radius: 0 8px 8px 0;
  font-size: .95rem;
  font-style: italic;
  color: var(--ink-soft);
}

/* ---------------- teacher panel ---------------- */

.panel {
  position: fixed;
  z-index: 40;
  top: calc(var(--bar-h) + 8px);
  right: 14px;
  width: min(22rem, calc(100vw - 28px));
  max-height: calc(100vh - var(--bar-h) - 24px);
  overflow-y: auto;
  padding: 18px 20px 22px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  box-shadow: 0 16px 40px rgba(28, 36, 48, .18);
  font-family: var(--font-ui);
}
.panel[hidden] { display: none; }

.panel-head { display: flex; align-items: baseline; justify-content: space-between; gap: 10px; }
.panel-head h2 { margin: 0 0 4px; font-family: var(--font-ui); font-size: .95rem; }
.panel-head h2 span { font-family: var(--font-zh); font-size: .8rem; font-weight: 400; color: var(--ink-faint); margin-left: 6px; }
.panel-x { background: transparent; border: 0; color: var(--ink-faint); font-size: 15px; cursor: pointer; padding: 2px 4px; }

.panel .row { margin-top: 18px; }
.panel label { display: block; font-size: .78rem; font-weight: 600; color: var(--ink-soft); margin-bottom: 6px; }
/* Chinese inside a panel label, button or note: same line where it fits, its
   own line where it does not, always a shade quieter than the English. */
.panel label em, .panel-btn em, .row-note em {
  font-family: var(--font-zh);
  font-style: normal;
  font-weight: 400;
  color: var(--ink-faint);
}
.panel-btn em { margin-left: 5px; font-size: .82em; }
.panel-btn:not(.panel-btn-quiet) em { color: rgba(255, 255, 255, .78); }
.row-note em { display: block; margin-top: 3px; }
.row-check { display: flex; align-items: center; gap: 9px; cursor: pointer; margin-top: 16px; }
.row-check span { font-size: .88rem; font-weight: 600; color: var(--ink); }
.row-check em { font-family: var(--font-zh); font-style: normal; font-weight: 400; font-size: .8rem; color: var(--ink-faint); margin-left: 5px; }
.row-check input { width: 17px; height: 17px; accent-color: var(--navy); }

.panel select {
  width: 100%;
  font-family: var(--font-ui);
  font-size: .85rem;
  padding: 7px 9px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
  color: var(--ink);
}

.panel-btn {
  width: 100%;
  font-family: var(--font-ui);
  font-size: .87rem;
  font-weight: 600;
  color: #fff;
  background: var(--navy);
  border: 1px solid var(--navy);
  border-radius: 8px;
  padding: 9px 12px;
  cursor: pointer;
}
.panel-btn:hover { filter: brightness(1.12); }
.panel-btn-quiet { color: var(--ink-soft); background: var(--paper); border-color: var(--line); }
.panel-btn-quiet:hover { filter: none; border-color: var(--rule); }

.row-note { margin: 7px 0 0; font-size: .74rem; line-height: 1.5; color: var(--ink-faint); }

/* ---------------- small screens ---------------- */

@media (max-width: 620px) {
  body { font-size: 17px; }
  .cover h1 { font-size: 1.8rem; }
  .step-head { font-size: 1.3rem; grid-template-columns: 2rem 1fr; gap: 10px; }
  /* Stacked, the two halves need a visible seam or they read as one list. */
  .match-grid { grid-template-columns: 1fr; }
  .match .col-b { margin-top: 14px; padding-top: 14px; border-top: 1px dashed var(--rule); }
  .poll-btns { width: 100%; }
  .bar-title span { display: none; }
}

/* ---------------- print ----------------

   A handout: the lesson without the machinery. Everything hidden behind a tap
   is opened, and anything that only works with a mouse is dropped. */

@media print {
  /* Photographs are dropped: the handout is for the language, and a classroom
     printer should not spend its toner on stock photography. */
  .bar, #nav, .nav-scrim, .panel, .say, .zh-chip, .reveal, .tally, .hint,
  .photo { display: none !important; }
  body { font-size: 11pt; background: #fff; }
  .shell { display: block; padding: 0; }
  main { max-width: none; }
  .zh, .card-back, .starters, .why { display: block !important; }
  .step { break-before: page; padding-top: 0; }
  .cards { grid-template-columns: repeat(2, 1fr); }
  .card, .gap, .ask, .task, .role, .note, .goals { break-inside: avoid; }
  .gap.solved .opts { display: flex; }
  .slot { min-width: 9rem; border-bottom: 1px solid #999; color: transparent; }
}

/* ---------------- 站尾 / site footer ----------------

   同一段樣式複製到每一頁。各頁的色票變數名稱不一樣（兒童頁沒有 --ink-faint、
   成人頁沒有 --blue），所以每個顏色都串一條 fallback，缺哪一個都還是看得到。

   標誌是全站唯一的共用圖檔，放在 public/logo.png，子頁用 ../logo.png 取用。
   它本身就是連結，所以要把文字連結那條底線和左邊距擋掉——文字連結的樣式因此
   收窄成 .site-foot p a，不再套用到整個站尾裡的每個 a。 */

.site-foot {
  max-width: 46rem;
  margin: 0 auto;
  padding: 26px 20px 40px;
  border-top: 1px solid var(--line, #e3e0d8);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 6px 14px;
  /* 換行之後（手機）文字會落到標誌下面一整行，置中才不會左右不對稱。 */
  text-align: center;
  font-family: var(--font-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif);
  font-size: .8rem;
  line-height: 1.7;
  color: var(--ink-faint, var(--ink-soft, #7a8290));
}
.site-foot p { margin: 0; }

.site-foot .site-mark {
  flex: none;
  margin: 0;
  padding: 0;
  border: 0;
  line-height: 0;
  border-radius: 50%;
  transition: opacity .12s;
}
.site-foot .site-mark img { display: block; width: 34px; height: 34px; }
.site-foot .site-mark:hover { opacity: .78; }

.site-foot p a {
  margin-left: 7px;
  padding-bottom: 1px;
  color: var(--navy, var(--blue, #1d3f6e));
  font-weight: 600;
  text-decoration: none;
  border-bottom: 1px solid currentColor;
}
.site-foot p a:hover { opacity: .7; }

@media print { .site-foot { display: none; } }