/* ==========================================================================
   Lingua

   The surface reads as a well-set book rather than a dashboard: a serif for
   anything the learner reads as English, a clean sans for the machinery around
   it, generous line height, and one warm accent that means "this is where the
   action is" and nothing else. Correct and wrong get their own colours and no
   others compete with them.
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Fraunces:opsz,wght@9..144,400;9..144,500;9..144,600;9..144,700&family=Inter:wght@400;450;500;600&family=JetBrains+Mono:wght@400;500&display=swap');

:root {
  --paper: #FBFAF8;
  --card: #FFFFFF;
  --ink: #1B1D22;
  --ink-soft: #4A5058;
  --muted: #838B95;
  --rule: #E6E3DD;
  --rule-soft: #F0EEE9;

  --accent: #C2410C;
  --accent-soft: #FDF3EC;
  --right: #15694A;
  --right-soft: #EDF7F2;
  --wrong: #B02418;
  --wrong-soft: #FDF1EF;

  --serif: 'Fraunces', Georgia, serif;
  --sans: 'Inter', system-ui, -apple-system, sans-serif;
  --mono: 'JetBrains Mono', ui-monospace, monospace;

  --r-sm: 6px;
  --r-md: 10px;
  --r-lg: 16px;
  --shadow: 0 1px 2px rgba(27, 29, 34, .04), 0 8px 24px -12px rgba(27, 29, 34, .12);
  --shadow-lift: 0 2px 4px rgba(27, 29, 34, .05), 0 16px 40px -16px rgba(27, 29, 34, .18);
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #14161A;
    --card: #1B1E23;
    --ink: #F2F0EC;
    --ink-soft: #C3C7CE;
    --muted: #8A929C;
    --rule: #2C3037;
    --rule-soft: #23262C;
    --accent: #F97316;
    --accent-soft: #2A1D14;
    --right: #4ADE9B;
    --right-soft: #16241E;
    --wrong: #F87171;
    --wrong-soft: #2A1917;
    --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 8px 24px -12px rgba(0, 0, 0, .6);
    --shadow-lift: 0 2px 4px rgba(0, 0, 0, .4), 0 16px 40px -16px rgba(0, 0, 0, .7);
  }
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--sans);
  background: var(--paper);
  color: var(--ink);
  line-height: 1.6;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

::selection { background: var(--accent-soft); color: var(--accent); }

/* --------------------------------------------------------------- layout */

.shell { max-width: 860px; margin: 0 auto; padding: 0 20px 96px; }

header.top {
  position: sticky;
  top: 0;
  z-index: 40;
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--rule);
}

.top-inner {
  max-width: 860px;
  margin: 0 auto;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  gap: 14px;
}

.logo {
  font-family: var(--serif);
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: -.02em;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
}
.logo .mark {
  width: 22px; height: 22px;
  border-radius: 6px;
  background: var(--accent);
  display: grid; place-items: center;
  color: #fff; font-size: .78rem; font-weight: 600;
  font-family: var(--sans);
}

.top-spacer { flex: 1; }

.streak {
  font-family: var(--mono);
  font-size: .76rem;
  color: var(--accent);
  background: var(--accent-soft);
  padding: 4px 9px;
  border-radius: 999px;
  white-space: nowrap;
}
.streak.hidden { display: none; }

/* --------------------------------------------------------------- controls */

.icon-btn {
  border: 1px solid var(--rule);
  background: var(--card);
  color: var(--ink-soft);
  width: 34px; height: 34px;
  border-radius: var(--r-sm);
  display: grid; place-items: center;
  cursor: pointer;
  transition: border-color .15s, color .15s;
}
.icon-btn:hover { border-color: var(--muted); color: var(--ink); }
.icon-btn svg { width: 17px; height: 17px; }

button, .btn {
  font-family: var(--sans);
  font-size: .93rem;
  font-weight: 500;
  border-radius: var(--r-sm);
  border: 1px solid transparent;
  padding: 10px 18px;
  cursor: pointer;
  transition: transform .12s, background .15s, border-color .15s, opacity .15s;
}
button:active:not(:disabled) { transform: translateY(1px); }
button:disabled { opacity: .45; cursor: not-allowed; }

.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover:not(:disabled) { background: color-mix(in srgb, var(--accent) 88%, #000); }

.btn-ghost { background: transparent; border-color: var(--rule); color: var(--ink); }
.btn-ghost:hover:not(:disabled) { border-color: var(--muted); }

.btn-quiet {
  background: transparent; border: none; color: var(--muted);
  padding: 6px 8px; font-size: .86rem;
}
.btn-quiet:hover { color: var(--ink); }

.btn-row { display: flex; gap: 10px; flex-wrap: wrap; }

input[type="text"], textarea, select {
  font-family: var(--sans);
  font-size: 1rem;
  width: 100%;
  padding: 13px 15px;
  border: 1px solid var(--rule);
  border-radius: var(--r-md);
  background: var(--card);
  color: var(--ink);
  transition: border-color .15s, box-shadow .15s;
}
input[type="text"]:focus, textarea:focus, select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}
textarea { resize: vertical; min-height: 150px; line-height: 1.6; }
::placeholder { color: var(--muted); }

/* --------------------------------------------------------------- pieces */

.eyebrow {
  font-family: var(--mono);
  font-size: .68rem;
  letter-spacing: .13em;
  text-transform: uppercase;
  color: var(--muted);
  display: block;
  margin-bottom: 10px;
}

.card {
  background: var(--card);
  border: 1px solid var(--rule);
  border-radius: var(--r-lg);
  padding: 24px;
  box-shadow: var(--shadow);
}

.hero { padding: 44px 0 30px; }
.hero h1 {
  font-family: var(--serif);
  font-size: clamp(2.1rem, 6vw, 3rem);
  font-weight: 600;
  line-height: 1.08;
  letter-spacing: -.03em;
  margin-bottom: 12px;
}
.hero p { color: var(--ink-soft); font-size: 1.06rem; max-width: 40ch; }

/* --------------------------------------------------------------- tabs */

.tabs {
  display: flex;
  gap: 2px;
  background: var(--rule-soft);
  padding: 3px;
  border-radius: var(--r-md);
  margin-bottom: 18px;
}
.tab {
  flex: 1;
  background: transparent;
  border: none;
  padding: 9px 10px;
  border-radius: 7px;
  font-size: .88rem;
  font-weight: 500;
  color: var(--muted);
}
.tab.active { background: var(--card); color: var(--ink); box-shadow: var(--shadow); }

.panel { display: none; }
.panel.active { display: block; }

.chips { display: flex; flex-wrap: wrap; gap: 7px; margin-top: 12px; }
.chip {
  font-size: .84rem;
  padding: 6px 12px;
  border-radius: 999px;
  border: 1px solid var(--rule);
  background: var(--card);
  color: var(--ink-soft);
}
.chip:hover { border-color: var(--accent); color: var(--accent); }

/* --------------------------------------------------------------- dropzone */

.dropzone {
  border: 1.5px dashed var(--rule);
  border-radius: var(--r-lg);
  padding: 44px 24px;
  text-align: center;
  cursor: pointer;
  transition: border-color .15s, background .15s;
}
.dropzone:hover, .dropzone.over { border-color: var(--accent); background: var(--accent-soft); }
.dropzone svg { width: 30px; height: 30px; color: var(--muted); margin-bottom: 10px; }
.dropzone strong { display: block; font-weight: 500; margin-bottom: 4px; }
.dropzone span { color: var(--muted); font-size: .87rem; }
.preview { max-width: 100%; border-radius: var(--r-md); margin-top: 16px; }

/* --------------------------------------------------------------- settings */

.settings { display: grid; gap: 18px; margin-top: 22px; }
.field label {
  display: block;
  font-size: .8rem;
  font-weight: 500;
  color: var(--ink-soft);
  margin-bottom: 7px;
}

.segmented { display: flex; gap: 5px; flex-wrap: wrap; }
.segmented button {
  flex: 1;
  min-width: 58px;
  padding: 9px 6px;
  border: 1px solid var(--rule);
  background: var(--card);
  border-radius: var(--r-sm);
  font-size: .85rem;
  color: var(--ink-soft);
}
.segmented button.on {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 500;
}
.segmented .sub { display: block; font-size: .68rem; color: var(--muted); margin-top: 1px; }
.segmented button.on .sub { color: var(--accent); }

/* --------------------------------------------------------------- lesson */

.lesson-head { margin-bottom: 26px; }
.lesson-head h2 {
  font-family: var(--serif);
  font-size: 1.85rem;
  font-weight: 600;
  letter-spacing: -.02em;
  line-height: 1.2;
}
.lesson-meta {
  font-family: var(--mono);
  font-size: .72rem;
  color: var(--muted);
  letter-spacing: .06em;
  text-transform: uppercase;
  margin-top: 6px;
}

.prose {
  font-family: var(--serif);
  font-size: 1.1rem;
  line-height: 1.72;
  color: var(--ink);
}
.prose + .prose { margin-top: 14px; }

.rule-card {
  border-left: 2px solid var(--rule);
  padding-left: 18px;
  margin-bottom: 22px;
}
.rule-card h4 { font-size: 1rem; font-weight: 600; margin-bottom: 5px; }
.rule-card .form {
  font-family: var(--mono);
  font-size: .81rem;
  color: var(--accent);
  margin-bottom: 9px;
}
.rule-card .ex {
  font-family: var(--serif);
  font-size: 1.03rem;
  color: var(--ink);
  margin: 3px 0;
  display: flex;
  align-items: center;
  gap: 8px;
}
.rule-card .note {
  font-size: .87rem;
  color: var(--muted);
  margin-top: 10px;
  padding-top: 9px;
  border-top: 1px dashed var(--rule);
}

.mistake { margin-bottom: 16px; }
.mistake .pair { display: flex; flex-direction: column; gap: 3px; font-family: var(--serif); font-size: 1.02rem; }
.mistake .x { color: var(--wrong); text-decoration: line-through; text-decoration-thickness: 1px; }
.mistake .v { color: var(--right); }
.mistake .why { font-family: var(--sans); font-size: .86rem; color: var(--muted); margin-top: 5px; }

.speak {
  border: none; background: transparent; padding: 2px;
  color: var(--muted); cursor: pointer; line-height: 0;
}
.speak:hover { color: var(--accent); }
.speak svg { width: 15px; height: 15px; }

/* --------------------------------------------------------------- questions */

.question { margin-bottom: 30px; }
.q-head {
  font-family: var(--mono);
  font-size: .68rem;
  letter-spacing: .11em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 7px;
}
.q-stem {
  font-family: var(--serif);
  font-size: 1.18rem;
  line-height: 1.5;
  margin-bottom: 14px;
}
.q-stem .blank {
  display: inline-block;
  min-width: 74px;
  border-bottom: 2px solid var(--accent);
  margin: 0 3px;
}

.options { display: grid; gap: 8px; }
.option {
  text-align: left;
  padding: 13px 16px;
  border: 1px solid var(--rule);
  background: var(--card);
  border-radius: var(--r-md);
  font-size: .98rem;
  color: var(--ink);
  display: flex;
  align-items: center;
  gap: 11px;
}
.option:hover:not(:disabled) { border-color: var(--muted); }
.option .key {
  font-family: var(--mono);
  font-size: .72rem;
  width: 21px; height: 21px;
  border-radius: 5px;
  background: var(--rule-soft);
  color: var(--muted);
  display: grid; place-items: center;
  flex-shrink: 0;
}
.option.picked { border-color: var(--accent); background: var(--accent-soft); }
.option.picked .key { background: var(--accent); color: #fff; }
.option.correct { border-color: var(--right); background: var(--right-soft); }
.option.incorrect { border-color: var(--wrong); background: var(--wrong-soft); }

.verdict {
  margin-top: 12px;
  padding: 12px 15px;
  border-radius: var(--r-md);
  font-size: .92rem;
}
.verdict.right { background: var(--right-soft); color: var(--right); }
.verdict.wrong { background: var(--wrong-soft); color: var(--wrong); }
.verdict .answer { font-family: var(--serif); font-size: 1.04rem; margin: 4px 0; }
.verdict .why { color: var(--ink-soft); margin-top: 6px; }
.verdict .trap {
  margin-top: 9px;
  padding-top: 9px;
  border-top: 1px dashed currentColor;
  font-size: .86rem;
  opacity: .85;
}

/* --------------------------------------------------------------- score */

.score-card { text-align: center; padding: 34px 24px; }
.score-num {
  font-family: var(--serif);
  font-size: 3.6rem;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.03em;
}
.score-label { color: var(--muted); font-size: .9rem; margin-top: 6px; }
.bar { height: 5px; background: var(--rule-soft); border-radius: 999px; overflow: hidden; margin: 20px 0 4px; }
.bar > i { display: block; height: 100%; background: var(--accent); border-radius: 999px; transition: width .6s cubic-bezier(.2,.8,.2,1); }

/* --------------------------------------------------------------- vocabulary */

.game { text-align: center; padding: 28px 20px; }
.game .word {
  font-family: var(--serif);
  font-size: 2.7rem;
  font-weight: 600;
  letter-spacing: -.02em;
  margin-bottom: 4px;
}
.game .pos {
  font-family: var(--mono);
  font-size: .72rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 24px;
}
.game .options { text-align: left; max-width: 460px; margin: 0 auto; }

/* --------------------------------------------------------------- stats */

.stat-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-bottom: 24px; }
.stat { text-align: center; padding: 18px 10px; }
.stat b { font-family: var(--serif); font-size: 1.9rem; font-weight: 600; display: block; }
.stat span { font-size: .78rem; color: var(--muted); }

.skill-row { display: flex; align-items: center; gap: 12px; margin-bottom: 11px; font-size: .89rem; }
.skill-row .name { width: 130px; flex-shrink: 0; color: var(--ink-soft); }
.skill-row .track { flex: 1; height: 7px; background: var(--rule-soft); border-radius: 999px; overflow: hidden; }
.skill-row .fill { height: 100%; border-radius: 999px; }
.skill-row .pct { font-family: var(--mono); font-size: .78rem; color: var(--muted); width: 38px; text-align: right; }

/* --------------------------------------------------------------- chat */

.chat-log { display: flex; flex-direction: column; gap: 12px; margin-bottom: 16px; }
.bubble { padding: 12px 15px; border-radius: var(--r-md); font-size: .94rem; max-width: 88%; }
.bubble.me { align-self: flex-end; background: var(--accent-soft); color: var(--accent); }
.bubble.bot { align-self: flex-start; background: var(--rule-soft); color: var(--ink); }
.chat-form { display: flex; gap: 8px; }

/* --------------------------------------------------------------- misc */

.report { margin-top: 20px; border-top: 1px solid var(--rule); padding-top: 14px; }
.report summary { cursor: pointer; font-size: .84rem; color: var(--muted); }
.report table { width: 100%; border-collapse: collapse; margin-top: 12px; font-size: .82rem; }
.report td { padding: 6px 8px; border-bottom: 1px solid var(--rule-soft); color: var(--ink-soft); vertical-align: top; }
.report td:last-child { color: var(--muted); white-space: nowrap; }

.toast {
  position: fixed;
  left: 50%;
  bottom: 28px;
  transform: translate(-50%, 90px);
  background: var(--ink);
  color: var(--paper);
  padding: 11px 20px;
  border-radius: 999px;
  font-size: .89rem;
  z-index: 90;
  transition: transform .3s cubic-bezier(.2,.8,.2,1);
  max-width: calc(100vw - 40px);
}
.toast.show { transform: translate(-50%, 0); }

.loading { text-align: center; padding: 60px 20px; }
.spinner {
  width: 26px; height: 26px;
  border: 2px solid var(--rule);
  border-top-color: var(--accent);
  border-radius: 50%;
  margin: 0 auto 16px;
  animation: spin .8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }
.loading p { color: var(--muted); font-size: .92rem; }

.error-box {
  background: var(--wrong-soft);
  color: var(--wrong);
  padding: 14px 16px;
  border-radius: var(--r-md);
  font-size: .9rem;
  margin-bottom: 16px;
}

.view { display: none; }
.view.active { display: block; animation: rise .32s cubic-bezier(.2,.8,.2,1); }
@keyframes rise { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }

.sticky-actions {
  position: sticky;
  bottom: 0;
  background: linear-gradient(transparent, var(--paper) 28%);
  padding: 22px 0 16px;
  margin-top: 8px;
}

.section-nav { display: flex; gap: 4px; margin-bottom: 22px; border-bottom: 1px solid var(--rule); }
.section-nav button {
  background: none; border: none; border-bottom: 2px solid transparent;
  padding: 9px 13px; font-size: .9rem; color: var(--muted); border-radius: 0;
}
.section-nav button.on { color: var(--ink); border-bottom-color: var(--accent); font-weight: 500; }

.empty { text-align: center; padding: 46px 20px; color: var(--muted); }
.empty p { max-width: 34ch; margin: 0 auto; font-size: .93rem; }

@media (max-width: 620px) {
  .shell { padding: 0 16px 80px; }
  .hero { padding: 30px 0 22px; }
  .card { padding: 18px; border-radius: var(--r-md); }
  .stat-grid { gap: 8px; }
  .skill-row .name { width: 92px; font-size: .82rem; }
  .game .word { font-size: 2.1rem; }
}

@media print {
  header.top, .sticky-actions, .section-nav, button { display: none !important; }
  body { background: #fff; }
}