:root {
  --bg: #f4f5f7;
  --surface: #ffffff;
  --surface-2: #eceef2;
  --text: #1a1d24;
  --muted: #667085;
  --border: #dfe3ea;
  --primary: #2f5bd0;
  --primary-ink: #ffffff;
  --accent: #f0b429;
  --good: #1f9d55;
  --bad: #d64545;
  --ok: #c98a04;
  --radius: 14px;
  --maxw: 620px;
  --safe-b: env(safe-area-inset-bottom, 0px);
}
:root[data-theme="dark"], :root:not([data-theme="light"]) {
  --bg: #0e1117;
  --surface: #171b23;
  --surface-2: #1f242e;
  --text: #e8eaee;
  --muted: #9aa4b2;
  --border: #2b313c;
  --primary: #5b86e5;
  --primary-ink: #0b0e13;
  --accent: #f0b429;
  --good: #35c07a;
  --bad: #ef6d6d;
  --ok: #e0a63a;
}
:root[data-theme="light"] {
  --bg: #f4f5f7; --surface: #fff; --surface-2: #eceef2; --text: #1a1d24;
  --muted: #667085; --border: #dfe3ea; --primary: #2f5bd0; --primary-ink: #fff;
  --good: #1f9d55; --bad: #d64545; --ok: #c98a04;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  background: var(--bg); color: var(--text);
  font: 16px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  padding-bottom: calc(64px + var(--safe-b));
}
a { color: var(--primary); text-decoration: none; }
h1 { font-size: 1.5rem; margin: 0 0 .3em; }
h2 { font-size: 1.25rem; margin: 0 0 .4em; }
h3 { font-size: 1rem; margin: 1.4em 0 .5em; color: var(--muted); text-transform: uppercase; letter-spacing: .04em; font-weight: 700; }
.muted { color: var(--muted); }
.small { font-size: .85rem; }

.appbar {
  position: sticky; top: 0; z-index: 20;
  background: var(--surface); border-bottom: 1px solid var(--border);
  padding: 12px 16px; padding-top: calc(12px + env(safe-area-inset-top, 0px));
}
.brand { font-weight: 800; letter-spacing: -.01em; color: var(--text); }

.screen { max-width: var(--maxw); margin: 0 auto; padding: 18px 16px 32px; }
.screen.no-pad { padding: 0; }
.screen.center { text-align: center; padding-top: 48px; }
.stack { display: flex; flex-direction: column; gap: 10px; margin: 16px 0; }
.row-btns { display: flex; gap: 10px; flex-wrap: wrap; }

/* botões */
.btn {
  appearance: none; border: 1px solid var(--border); background: var(--surface);
  color: var(--text); padding: 12px 16px; border-radius: 12px; font-size: 1rem;
  font-weight: 600; cursor: pointer; text-align: center; transition: transform .05s, background .15s;
}
.btn:active { transform: scale(.98); }
.btn:disabled { opacity: .45; cursor: default; }
.btn-primary { background: var(--primary); color: var(--primary-ink); border-color: transparent; }
.btn-danger { color: var(--bad); border-color: var(--bad); }
.btn-ghost { background: transparent; }
.btn-lg { padding: 14px 18px; }
.btn-xl { padding: 18px; font-size: 1.1rem; }
.btn-sm { padding: 7px 11px; font-size: .85rem; font-weight: 600; }
.btn-speak { display: inline-flex; align-items: center; gap: 6px; align-self: flex-start; }
.btn-speak.btn-icon { padding: 8px 10px; }
.ico { font-size: .95em; }

/* home */
.home-head p { margin-top: 0; }
.stat-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin: 16px 0; }
.stat { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; }
.stat-value { font-size: 1.8rem; font-weight: 800; line-height: 1; }
.stat-label { color: var(--muted); font-size: .85rem; margin-top: 6px; }
.stat.streak .stat-value { color: var(--accent); }
.stat.due .stat-value { color: var(--primary); }
.done-badge { background: color-mix(in srgb, var(--good) 15%, transparent); color: var(--good); border-radius: 10px; padding: 10px 12px; font-weight: 600; text-align: center; margin-bottom: 8px; }
.home-links { display: flex; justify-content: space-between; margin-top: 20px; font-size: .9rem; }
.streak-strip { margin-top: 28px; }
.hgrid { display: grid; grid-template-columns: repeat(14, 1fr); gap: 4px; margin-top: 8px; }
.hcell { aspect-ratio: 1; border-radius: 3px; background: var(--surface-2); }
.hcell.on { background: var(--accent); }

/* fila de treino */
.q-wrap { max-width: var(--maxw); margin: 0 auto; padding: 12px 16px 40px; }
.q-top { display: flex; justify-content: space-between; align-items: center; gap: 12px; }
.q-title { font-weight: 700; font-size: .95rem; }
.qbar { height: 6px; background: var(--surface-2); border-radius: 99px; overflow: hidden; margin: 12px 0; }
.qbar-fill { height: 100%; background: var(--primary); width: 0; transition: width .3s; }
.q-heading { display: flex; justify-content: space-between; color: var(--muted); font-size: .85rem; margin-bottom: 10px; }
.q-mode { background: var(--surface-2); padding: 2px 8px; border-radius: 99px; font-weight: 600; }

.card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 20px; display: flex; flex-direction: column; gap: 14px;
}
.frame-chip {
  align-self: flex-start; background: color-mix(in srgb, var(--primary) 14%, transparent);
  color: var(--primary); font-weight: 700; padding: 6px 12px; border-radius: 99px; font-size: .95rem;
}
.prompt-block .prompt-pt { color: var(--muted); font-size: .9rem; }
.prompt-target { font-size: 1.35rem; font-weight: 600; }
.prompt-sub, .hint-line { color: var(--muted); font-size: .88rem; }
.answer { display: flex; flex-direction: column; gap: 6px; border-top: 1px dashed var(--border); padding-top: 12px; }
.hidden { display: none !important; }
.answer-en { font-size: 1.3rem; font-weight: 700; }
.answer-pt { color: var(--muted); }

.sentence-input {
  width: 100%; padding: 13px 14px; font-size: 1.05rem; border-radius: 12px;
  border: 1px solid var(--border); background: var(--bg); color: var(--text);
}
.sentence-input:focus { outline: 2px solid var(--primary); border-color: transparent; }

.feedback { border-radius: 12px; padding: 14px; display: flex; flex-direction: column; gap: 8px; }
.feedback.ok { background: color-mix(in srgb, var(--good) 12%, transparent); }
.feedback.bad { background: color-mix(in srgb, var(--bad) 10%, transparent); }
.fb-label { font-weight: 700; }
.fb-expected { font-size: 1.15rem; font-weight: 600; }
.fb-mine { color: var(--muted); font-size: .9rem; }
.fb-pt { color: var(--muted); }
.w-add { color: var(--bad); text-decoration: line-through; }
.w-del { color: var(--good); font-weight: 700; }

/* blocos */
.build-slots, .build-pool { display: flex; flex-wrap: wrap; gap: 8px; min-height: 44px; }
.build-slots { background: var(--bg); border: 1px dashed var(--border); border-radius: 12px; padding: 10px; }
.build-divider { text-align: center; color: var(--muted); font-size: .78rem; text-transform: uppercase; letter-spacing: .08em; }
.chunk {
  background: var(--surface-2); border: 1px solid var(--border); color: var(--text);
  padding: 9px 12px; border-radius: 10px; font-size: 1rem; cursor: pointer; font-weight: 600;
}
.chunk.placed { background: var(--primary); color: var(--primary-ink); border-color: transparent; }
.chunk:disabled { opacity: .6; }

.listen-reveal { display: flex; flex-direction: column; gap: 4px; }
.mic-result { font-size: .9rem; min-height: 1.2em; }
.mic-hit { color: var(--good); font-weight: 700; }
.mic-miss { color: var(--muted); }

/* gradebar */
.gradebar { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 8px; max-width: var(--maxw); margin: 12px auto 0; }
.grade { padding: 14px 6px; font-weight: 700; }
.g-again { color: var(--bad); border-color: color-mix(in srgb, var(--bad) 40%, var(--border)); }
.g-ok { color: var(--ok); border-color: color-mix(in srgb, var(--ok) 40%, var(--border)); }
.g-easy { color: var(--good); border-color: color-mix(in srgb, var(--good) 40%, var(--border)); }
.grade.suggested { box-shadow: 0 0 0 2px currentColor inset; }
.grade-slot { max-width: var(--maxw); margin: 0 auto; }

/* passos extras da sessão */
.step-tag { display: inline-block; background: var(--surface-2); color: var(--muted); padding: 4px 10px; border-radius: 99px; font-size: .78rem; font-weight: 700; text-transform: uppercase; letter-spacing: .05em; margin-bottom: 10px; }
.vocab-list { display: flex; flex-direction: column; gap: 8px; margin: 14px 0; }
.vocab-row { display: grid; grid-template-columns: 1fr auto; gap: 4px 10px; background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 12px; align-items: center; }
.vocab-word { font-weight: 700; }
.vocab-ex { grid-column: 1 / -1; font-size: .95rem; }
.vocab-pt { display: block; color: var(--muted); font-size: .85rem; }
.fs-prompt { font-size: 1.3rem; font-weight: 600; margin: 8px 0; }
.fs-hint { color: var(--muted); background: var(--surface-2); padding: 10px 12px; border-radius: 10px; }
.timer { font-size: 2.4rem; font-weight: 800; text-align: center; margin: 16px 0; font-variant-numeric: tabular-nums; }
.timer.done { color: var(--accent); }
.big-check { font-size: 3rem; color: var(--good); }

/* estruturas */
.chips { display: flex; gap: 8px; overflow-x: auto; padding-bottom: 6px; margin-bottom: 8px; }
.chip { white-space: nowrap; border: 1px solid var(--border); background: var(--surface); color: var(--muted); padding: 7px 12px; border-radius: 99px; font-size: .85rem; font-weight: 600; cursor: pointer; }
.chip.on { background: var(--primary); color: var(--primary-ink); border-color: transparent; }
.struct-group { margin-bottom: 18px; }
.struct-row { display: flex; align-items: center; gap: 10px; padding: 13px 12px; background: var(--surface); border: 1px solid var(--border); border-radius: 10px; margin-bottom: 6px; color: var(--text); }
.struct-main { flex: 1; display: flex; flex-direction: column; gap: 2px; min-width: 0; }
.struct-frame { font-weight: 600; }
.struct-cat { font-size: .74rem; color: var(--muted); }
.struct-due { font-size: .76rem; color: var(--muted); white-space: nowrap; }
.dot { width: 10px; height: 10px; border-radius: 99px; background: var(--surface-2); flex: none; border: 1px solid var(--border); }
.dot.new { background: var(--surface-2); }
.dot.learning { background: var(--accent); border-color: transparent; }
.dot.known { background: var(--good); border-color: transparent; }

.back { display: inline-block; margin-bottom: 12px; font-size: .9rem; }
.detail-head { display: flex; align-items: center; gap: 10px; }
.ex-list { display: flex; flex-direction: column; gap: 8px; }
.ex-item { background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 14px; }
.ex-en { font-weight: 700; }
.ex-pt { color: var(--muted); margin: 2px 0 8px; }
.mode-btns, .mode-btns { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }

/* ajustes */
.set-row { display: flex; flex-direction: column; gap: 6px; background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 14px; margin-bottom: 10px; }
.set-row label { font-weight: 600; display: flex; justify-content: space-between; }
.set-row select, .set-row input[type=range] { width: 100%; padding: 8px; border-radius: 8px; border: 1px solid var(--border); background: var(--bg); color: var(--text); }
.set-row.toggle { flex-direction: row; align-items: center; justify-content: space-between; }
.rate-val { color: var(--muted); font-variant-numeric: tabular-nums; }
.about { margin-top: 24px; }

/* tabbar */
.tabbar {
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 30;
  display: flex; background: var(--surface); border-top: 1px solid var(--border);
  padding-bottom: var(--safe-b);
}
.tabbar a {
  flex: 1; display: flex; flex-direction: column; align-items: center; gap: 2px;
  padding: 9px 4px 8px; color: var(--muted); font-size: .68rem; font-weight: 600;
}
.tabbar a.active { color: var(--primary); }
.tabbar .ti { font-size: 1.1rem; line-height: 1; }

@media (min-width: 640px) {
  .mode-btns { grid-template-columns: repeat(4, 1fr); }
}