:root {
  --bg: #14171c;
  --panel: #1c2026;
  --panel-2: #232830;
  --text: #e8eaed;
  --muted: #8a93a0;
  --accent: #4f8cff;
  --accent-press: #3b76ea;
  --good: #2ea66a;
  --good-soft: #1c4030;
  --bad: #d4495a;
  --bad-soft: #3c1f25;
  --border: #2c323b;
  --kbd-bg: #2a2f38;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

#app {
  max-width: 760px;
  margin: 0 auto;
  padding: 24px 16px 80px;
  min-height: 100vh;
}

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

.hidden { display: none !important; }
.muted { color: var(--muted); }
.small { font-size: 0.85rem; }

h1 {
  font-size: 1.7rem;
  margin: 0 0 8px;
  font-weight: 600;
}

h2 { margin: 0; font-weight: 600; }

code, kbd {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.88em;
  background: var(--kbd-bg);
  padding: 1px 6px;
  border-radius: 4px;
}

/* ───── start screen ───── */

.controls {
  display: grid;
  gap: 14px;
  margin: 22px 0 14px;
}

.controls label {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.controls label > span {
  font-size: 0.85rem;
  color: var(--muted);
}

select {
  width: 100%;
  background: var(--panel);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 12px;
  font-size: 1rem;
  font-family: inherit;
  appearance: none;
  -webkit-appearance: none;
}

fieldset.length {
  border: none;
  padding: 0;
  margin: 0;
}

fieldset.length legend {
  font-size: 0.85rem;
  color: var(--muted);
  padding: 0 0 6px;
}

.length-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.length-buttons .len {
  flex: 1;
  min-width: 56px;
  padding: 9px 10px;
  background: var(--panel);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.95rem;
  font-family: inherit;
}

.length-buttons .len:hover { background: var(--panel-2); }
.length-buttons .len.active {
  background: var(--accent);
  border-color: var(--accent);
  color: white;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 18px 0 8px;
}

button.primary, button.secondary {
  flex: 1;
  min-width: 140px;
  padding: 14px 18px;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  font-family: inherit;
  font-weight: 600;
  cursor: pointer;
}

button.primary {
  background: var(--accent);
  color: white;
}
button.primary:hover { background: var(--accent-press); }
button.primary:disabled {
  background: var(--panel-2);
  color: var(--muted);
  cursor: not-allowed;
}

button.secondary {
  background: var(--panel);
  color: var(--text);
  border: 1px solid var(--border);
  font-weight: 500;
}
button.secondary:hover { background: var(--panel-2); }

button.link {
  background: none;
  border: none;
  color: var(--muted);
  cursor: pointer;
  font-size: 0.9rem;
  padding: 4px 8px;
  font-family: inherit;
}
button.link:hover { color: var(--text); }

.footer-note { margin-top: 28px; }
.footer-note kbd { font-size: 0.78rem; }

.error {
  background: var(--bad-soft);
  border: 1px solid var(--bad);
  border-radius: 8px;
  padding: 12px 14px;
  margin-bottom: 16px;
}
.error p { margin: 6px 0 0; }
.error code { background: rgba(0,0,0,0.3); }

/* ───── quiz screen ───── */

.topbar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 8px 0 16px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 22px;
}

.progress { font-size: 0.95rem; color: var(--muted); }
.score {
  flex: 1;
  font-size: 0.95rem;
  font-variant-numeric: tabular-nums;
}

.qcard {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

#q-meta { margin: 0; }

.qtext {
  font-size: 1.35rem;
  line-height: 1.4;
  margin: 0 0 4px;
  word-break: break-word;
}

.answers {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
}

@media (min-width: 640px) {
  .answers {
    grid-template-columns: 1fr 1fr;
  }
}

.ans {
  display: flex;
  align-items: center;
  gap: 12px;
  text-align: left;
  padding: 14px 16px;
  background: var(--panel);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 10px;
  font-size: 1rem;
  font-family: inherit;
  cursor: pointer;
  word-break: break-word;
  min-width: 0;
  transition: background 0.08s;
}

.ans:hover:not(:disabled) { background: var(--panel-2); }

.ans .num {
  flex-shrink: 0;
  width: 26px;
  height: 26px;
  background: var(--panel-2);
  border-radius: 6px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--muted);
}

.ans .label { flex: 1; min-width: 0; }

.ans:disabled { cursor: default; }

/* answered states */
.ans.picked-correct {
  background: var(--good-soft);
  border-color: var(--good);
  color: var(--text);
}
.ans.picked-correct .num { background: var(--good); color: white; }

.ans.picked-wrong {
  background: var(--bad-soft);
  border-color: var(--bad);
}
.ans.picked-wrong .num { background: var(--bad); color: white; }

.ans.shown-correct {
  border-color: var(--good);
  outline: 2px solid var(--good);
  outline-offset: -2px;
}
.ans.shown-correct .num { background: var(--good); color: white; }

.ans.dim { opacity: 0.55; }

/* ───── feedback strip ───── */

.feedback {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.feedback.correct { border-color: var(--good); }
.feedback.wrong { border-color: var(--bad); }

.feedback-line {
  margin: 0;
  font-size: 1rem;
  font-weight: 500;
}
.feedback-line .ok { color: var(--good); font-weight: 600; }
.feedback-line .no { color: var(--bad); font-weight: 600; }

.source {
  display: flex;
  flex-direction: column;
  gap: 4px;
  border-top: 1px solid var(--border);
  padding-top: 10px;
}

.source a {
  color: var(--accent);
  text-decoration: none;
  font-size: 0.9rem;
}
.source a:hover { text-decoration: underline; }

.source p {
  margin: 0;
  word-break: break-word;
}

.next-btn { margin-top: 4px; }

/* ───── flag chips ───── */

.flag-row {
  display: flex;
  flex-direction: column;
  gap: 6px;
  border-top: 1px solid var(--border);
  padding-top: 10px;
}

.flag-row-label { font-size: 0.85rem; }

.flag-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.flag-chip {
  background: var(--panel-2);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 999px;
  padding: 6px 12px;
  font-size: 0.85rem;
  font-family: inherit;
  cursor: pointer;
  transition: background 0.08s, border-color 0.08s;
}

.flag-chip:hover { background: var(--border); }

.flag-chip.active {
  background: var(--accent);
  border-color: var(--accent);
  color: white;
}

.flag-chip.active.bad {
  background: var(--bad);
  border-color: var(--bad);
}

.flag-chip.active.good {
  background: var(--good);
  border-color: var(--good);
}

.footer-link { margin-top: 16px; text-align: center; }
.footer-link button.link { font-size: 0.85rem; }

/* ───── stats screen ───── */

.stats-h2 {
  font-size: 1rem;
  margin: 22px 0 10px;
  font-weight: 600;
  color: var(--muted);
}

.stats-totals {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 8px;
  margin: 12px 0 6px;
}

.stats-totals .cell {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 12px;
}

.stats-totals .cell .label {
  font-size: 0.78rem;
  color: var(--muted);
  display: block;
  margin-bottom: 2px;
}

.stats-totals .cell .num {
  font-size: 1.3rem;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

.stats-totals .cell.good { border-color: var(--good); }
.stats-totals .cell.bad { border-color: var(--bad); }

#stats-by-sub .row .val .pill {
  display: inline-block;
  font-size: 0.78rem;
  padding: 1px 7px;
  border-radius: 999px;
  margin-left: 4px;
  background: var(--panel-2);
  color: var(--muted);
}
#stats-by-sub .row .val .pill.bad { background: var(--bad-soft); color: var(--bad); }
#stats-by-sub .row .val .pill.good { background: var(--good-soft); color: var(--good); }

.stats-empty {
  margin: 18px 0;
  padding: 18px;
  background: var(--panel);
  border: 1px dashed var(--border);
  border-radius: 8px;
  color: var(--muted);
  text-align: center;
}

/* ───── end screen ───── */

.end-stats {
  font-size: 1.4rem;
  margin: 16px 0 8px;
}

.breakdown {
  margin: 14px 0 22px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.breakdown .row {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  background: var(--panel);
  border: 1px solid var(--border);
  padding: 8px 12px;
  border-radius: 6px;
  font-size: 0.92rem;
}

.breakdown .row .name { color: var(--muted); word-break: break-word; flex: 1; }
.breakdown .row .val { font-variant-numeric: tabular-nums; flex-shrink: 0; }