:root {
  --bg: #EEF0F3;
  --card: #FFFFFF;
  --ink: #1B1F27;
  --muted: #5F6776;
  --line: #D9DDE4;
  --accent: #2F5BEA;
  --accent-ink: #FFFFFF;
  --ok: #1F8A4C;
  --ok-bg: #E3F4EA;
  --no: #C43D3D;
  --no-bg: #FBE7E7;
  --gold: #D99A00;
  --hint-bg: #FFF6DC;
  --hint-ink: #6B4E00;
  --radius: 14px;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #12151B; --card: #1B2029; --ink: #E9ECF1; --muted: #9AA3B2; --line: #2E3542;
    --accent: #6D8DFF; --accent-ink: #0D1020; --ok: #5CCB8A; --ok-bg: #16301F; --no: #FF7B7B; --no-bg: #3A1B1B; --gold: #F2C14E; --hint-bg: #33290F; --hint-ink: #F2D58A;
  }
}
:root[data-theme="dark"] {
  --bg: #12151B; --card: #1B2029; --ink: #E9ECF1; --muted: #9AA3B2; --line: #2E3542;
  --accent: #6D8DFF; --accent-ink: #0D1020; --ok: #5CCB8A; --ok-bg: #16301F; --no: #FF7B7B; --no-bg: #3A1B1B; --gold: #F2C14E; --hint-bg: #33290F; --hint-ink: #F2D58A;
}

* { box-sizing: border-box; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font: 16px/1.5 "Instrument Sans", system-ui, sans-serif;
}
[lang="ja"] { font-family: "Noto Serif JP", serif; }
[lang="zh-CN"] { font-family: "Noto Serif SC", serif; }
h1, h2 { line-height: 1.2; margin: 0 0 8px; }
button { font: inherit; color: inherit; cursor: pointer; }
button:disabled { cursor: default; }

.top {
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  padding: 12px 16px; border-bottom: 1px solid var(--line); background: var(--card);
  position: sticky; top: 0; z-index: 5;
}
.brand { display: flex; align-items: center; gap: 10px; color: inherit; text-decoration: none; font-weight: 700; }
.brand-mark { display: grid; place-items: center; width: 34px; height: 34px; border-radius: 9px; background: var(--accent); color: var(--accent-ink); }

main { max-width: 640px; margin: 0 auto; padding: 20px 16px 60px; outline: none; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; }
.muted { color: var(--muted); }
.small { font-size: 14px; }
.link { background: none; border: 0; color: var(--accent); padding: 4px 6px; }

.btn {
  border: 1px solid var(--line); background: var(--card); border-radius: 12px;
  padding: 12px 18px; font-weight: 600;
}
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.row { display: flex; gap: 10px; flex-wrap: wrap; justify-content: center; }

.error { color: var(--no); margin: 0; }

/* trilha */
.langs { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; }
.lang {
  display: grid; justify-items: center; gap: 2px; padding: 12px 6px;
  border: 2px solid var(--line); background: var(--card); border-radius: var(--radius);
}
.lang.on { border-color: var(--accent); }
.lang .flag { font-size: 22px; font-weight: 700; }
.lang small { color: var(--muted); }
.bar { height: 10px; background: var(--line); border-radius: 999px; overflow: hidden; margin: 14px 0; flex: 1; }
.bar i { display: block; height: 100%; background: var(--ok); transition: width .3s; }

.levels { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin-top: 20px; }
.lvl {
  min-width: 0; display: grid; justify-items: center; gap: 0; padding: 8px 4px;
  border: 2px solid var(--line); background: var(--card); border-radius: 12px;
}
.lvl b { font-size: 14px; white-space: nowrap; }
.lvl small { color: var(--muted); font-size: 12px; }
.lvl.on { border-color: var(--accent); background: var(--accent); color: var(--accent-ink); }
.lvl.on small { color: inherit; opacity: .85; }
.lvl.complete:not(.on) { border-color: var(--ok); }
.level { margin-top: 20px; }
.abas { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; margin-top: 14px; padding: 4px; background: var(--line); border-radius: 12px; }
.aba { border: 0; background: transparent; border-radius: 9px; padding: 9px; font-weight: 600; color: var(--muted); }
.aba.on { background: var(--card); color: var(--ink); box-shadow: 0 1px 2px rgba(0,0,0,.12); }
.gramatica { display: grid; gap: 10px; margin-top: 14px; }
.regra { padding: 14px 18px; }
.regra summary { cursor: pointer; font-weight: 700; }
.regra .texto { margin-top: 12px; }
.regra .texto p { margin: 0 0 12px; }
.regra .kicker { margin: 6px 0 8px; text-align: left; }
.exemplos { list-style: none; padding: 0; margin: 0 0 14px; display: grid; gap: 8px; }
.exemplos li { display: flex; align-items: center; gap: 10px; }
.exemplos li > span { display: grid; min-width: 0; }
.exemplos small { color: var(--muted); }
.path { list-style: none; padding: 0; margin: 12px 0 0; display: grid; gap: 8px; }
.node button {
  width: 100%; display: flex; align-items: center; gap: 12px; text-align: left;
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 12px 14px;
}
.node .dot { flex: none; display: grid; place-items: center; width: 40px; height: 40px; border-radius: 50%; background: var(--line); font-size: 16px; }
.node .txt { flex: 1; min-width: 0; display: grid; }
.node .txt small { color: var(--muted); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.node .stars { color: var(--gold); letter-spacing: 1px; }
.node.done .dot { background: var(--ok); color: #fff; }
.node.next button { border: 2px solid var(--accent); }
.node.next .dot, .node.open .dot { background: var(--accent); color: var(--accent-ink); }
.node.locked button { opacity: .5; }
.node.rev .dot { border-radius: 10px; }

/* aula */
.lesson-top { display: flex; align-items: center; gap: 10px; margin-bottom: 16px; }
.lesson-top .bar { margin: 0; }
.lesson-top .small { flex: none; max-width: 35%; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.stage { display: grid; gap: 14px; justify-items: center; text-align: center; }
.kicker { margin: 0; text-transform: uppercase; letter-spacing: .08em; font-size: 12px; font-weight: 700; color: var(--muted); }
.word { display: grid; justify-items: center; gap: 4px; position: relative; }
.word .main { font-size: 26px; font-weight: 700; overflow-wrap: anywhere; }
.word.big .main { font-size: clamp(32px, 9vw, 52px); }
.word .sub { color: var(--muted); }
.word .say { position: static; }
.say { border: 1px solid var(--line); background: var(--bg); border-radius: 999px; padding: 6px 12px; font-size: 18px; }
.say.huge { font-size: 40px; padding: 18px 26px; }
.meaning { margin: 0; font-size: 20px; font-weight: 600; }
.meaning.big { font-size: 28px; }
.stars.huge { font-size: 44px; color: var(--gold); margin: 0; letter-spacing: 4px; }

.opts { width: 100%; display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.opt {
  display: grid; gap: 2px; align-content: center; min-height: 64px; padding: 10px;
  border: 2px solid var(--line); background: var(--card); border-radius: 12px; font-weight: 600; overflow-wrap: anywhere;
}
.opts.target .opt .main { font-size: 20px; }
.opt small { color: var(--muted); font-weight: 400; }
.opt.right { border-color: var(--ok); background: var(--ok-bg); }
.opt.wrong { border-color: var(--no); background: var(--no-bg); }
.opt.dim { opacity: .5; }
.feedback { width: 100%; display: flex; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap; padding: 12px 14px; border-radius: 12px; text-align: left; }
.feedback.ok { background: var(--ok-bg); color: var(--ok); }
.feedback.no { background: var(--no-bg); color: var(--no); }

.recap { list-style: none; padding: 0; margin: 0; width: 100%; display: grid; gap: 8px; }
.recap li { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 10px 12px; border: 1px solid var(--line); border-radius: 12px; }
.recap .word { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; justify-items: start; text-align: left; }
.recap .word .main { font-size: 20px; }
.recap li > span { color: var(--muted); text-align: right; }

/* revisão, ajustes e textos */
.aviso { margin-top: 4px; padding: 14px 18px; border-color: var(--gold); }
.aviso p { margin: 6px 0 0; font-size: 14px; color: var(--muted); }
.review { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 16px 18px; margin-top: 4px; }
.review > div { display: grid; }
.settings, .about { margin-top: 12px; padding: 14px 18px; }
.settings summary, .about summary { cursor: pointer; font-weight: 600; }
.settings label { display: flex; gap: 10px; align-items: center; margin-top: 12px; }
.settings input { width: 18px; height: 18px; accent-color: var(--accent); }
.voz { display: grid; grid-template-columns: minmax(0, 1fr); gap: 6px; margin-top: 14px; }
.voz label { font-weight: 600; }
.voz-row { display: flex; gap: 8px; min-width: 0; }
.voz select {
  flex: 1; min-width: 0; font: inherit; padding: 8px 10px; border-radius: 10px;
  border: 1px solid var(--line); background: var(--bg); color: var(--ink);
}
.voz .btn { flex: none; padding: 8px 12px; }
.about { margin-top: 32px; }
.about p { margin: 12px 0 0; }
.btn.skip { margin-top: 8px; font-size: 14px; padding: 8px 14px; }
.nota .texto { text-align: left; width: 100%; }
.nota .texto p { margin: 0 0 12px; }

/* exercícios */
.opt { position: relative; }
.opt kbd { position: absolute; top: 6px; left: 8px; font: 600 11px/1 "Instrument Sans", sans-serif; color: var(--muted); }
.opts.frases { grid-template-columns: 1fr; }
.opts.frases .opt .main { font-size: 17px; }
.word.frase .main { font-size: clamp(22px, 6vw, 30px); }
.word.big.frase .main { font-size: clamp(24px, 6.5vw, 34px); }

.typing { width: 100%; display: flex; flex-wrap: wrap; gap: 10px; }
.typing .btn { flex: 1 0 auto; }
.typing input {
  flex: 1 1 200px; min-width: 0; font: inherit; font-size: 18px; padding: 12px 14px; border-radius: 12px;
  border: 2px solid var(--line); background: var(--bg); color: var(--ink);
}
.typing input:focus { outline: none; border-color: var(--accent); }

.built {
  width: 100%; min-height: 64px; display: flex; flex-wrap: wrap; gap: 6px; align-items: center; justify-content: center;
  padding: 10px; border: 2px dashed var(--line); border-radius: 12px;
}
.built.ok { border-color: var(--ok); border-style: solid; }
.built.no { border-color: var(--no); border-style: solid; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; }
.chip {
  border: 2px solid var(--line); background: var(--card); border-radius: 10px; padding: 8px 12px;
  font-size: 18px; font-weight: 600; box-shadow: 0 2px 0 var(--line);
}
.chips .chip:disabled { opacity: .25; box-shadow: none; }
.built .chip { border-color: var(--accent); }

.btn.dica { border-color: var(--gold); color: var(--hint-ink); background: var(--card); font-size: 15px; padding: 8px 16px; }
.dica-box {
  width: 100%; text-align: left; padding: 12px 14px; border-radius: 12px;
  background: var(--hint-bg); color: var(--hint-ink); border: 1px solid var(--gold);
}
.dica-box p { margin: 0; }
.dica-box details { margin-top: 10px; color: var(--ink); }
.dica-box summary { cursor: pointer; font-weight: 600; color: var(--hint-ink); }
.dica-box .texto { margin-top: 8px; font-size: 15px; }
.dica-box .texto p { margin: 0 0 10px; }
.padrao { font: 600 18px/1.4 ui-monospace, SFMono-Regular, Menlo, monospace; letter-spacing: 2px; word-break: break-word; }
.opt.out { opacity: .25; text-decoration: line-through; }

.mic.on { animation: pulse 1s infinite; }
@keyframes pulse { 50% { opacity: .6; } }
.heard { margin: 0; color: var(--muted); }
.heard.ok { color: var(--ok); }

@media (max-width: 480px) {
  .card { padding: 18px; }
  .opts { grid-template-columns: 1fr; }
}

/* aulas de gramática */
.aula-card { display: grid; gap: 4px; text-align: left; padding: 16px 18px; width: 100%; }
.aula-card:hover { border-color: var(--accent); }
.aula-n { font-size: 12px; font-weight: 700; letter-spacing: .06em; text-transform: uppercase; color: var(--accent); }
.sub-h { margin: 18px 0 2px; font-size: 16px; color: var(--muted); }
.aula h1 { font-size: 26px; margin: 4px 0 10px; }
.aula .kicker { text-align: left; }
.aula .objetivo { background: var(--bg); border-radius: 10px; padding: 10px 12px; margin: 0 0 8px; }
.aula section { margin-top: 22px; }
.aula h2 { font-size: 19px; margin: 0 0 8px; }
.aula section p { margin: 0 0 10px; }
.aula .leitura { color: var(--accent); }
.tabela { overflow-x: auto; margin: 8px 0 12px; }
.tabela table { border-collapse: collapse; width: 100%; font-size: 15px; }
.tabela th, .tabela td { border: 1px solid var(--line); padding: 7px 9px; text-align: left; vertical-align: top; }
.tabela th { background: var(--bg); font-weight: 700; }
.erros { background: var(--no-bg); border-radius: 12px; padding: 12px 16px; }
.erros h2 { color: var(--no); }
.erros ul { margin: 0; padding-left: 18px; }
.erros li { margin: 4px 0; }
.questao { border: 1px solid var(--line); border-radius: 10px; padding: 10px 12px; margin-top: 8px; }
.questao summary { cursor: pointer; font-weight: 600; }
.questao summary span { color: var(--accent); }
.questao p { margin: 8px 0 0; color: var(--ok); font-weight: 600; }
.aula-nav { margin-top: 24px; }