:root {
  --bg: #f6f7fb;
  --card: #ffffff;
  --text: #1c2033;
  --muted: #646b85;
  --line: #e3e6ef;
  --accent: #4f46e5;
  --accent-soft: #eef0ff;
  --good: #15803d;
  --mid: #b45309;
  --low: #b91c1c;
  --warn-bg: #fff4e5;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font: 16px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
}
[hidden] { display: none !important; }

.top {
  display: flex; justify-content: space-between; align-items: center;
  padding: 14px 24px; background: var(--card); border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 20px; }
.logo {
  display: grid; place-items: center; width: 32px; height: 32px; border-radius: 8px;
  background: var(--accent); color: #fff; font-size: 18px;
}
.nav { display: flex; gap: 4px; flex-wrap: wrap; }
.nav button { border: none; background: transparent; color: var(--muted); padding: 8px 12px; }
.nav button.active { background: var(--accent-soft); color: var(--accent); font-weight: 600; }

main { max-width: 1100px; margin: 28px auto; padding: 0 16px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 24px; }
.narrow { max-width: 720px; margin: 0 auto; }
.layout { display: grid; grid-template-columns: minmax(0, 1fr) 320px; gap: 20px; align-items: start; }
@media (max-width: 860px) { .layout { grid-template-columns: 1fr; } }

h1 { margin: 0 0 8px; font-size: 28px; }
h1 em { color: var(--accent); font-style: normal; }
h2 { margin: 6px 0 12px; font-size: 22px; line-height: 1.35; }
h3 { margin: 0 0 12px; font-size: 16px; }
.muted { color: var(--muted); }

.drop {
  display: block; margin: 18px 0 10px; padding: 26px; text-align: center; cursor: pointer;
  border: 2px dashed var(--line); border-radius: 12px; color: var(--muted);
}
.drop:hover { border-color: var(--accent); color: var(--accent); }
.drop input { display: none; }
details { margin-bottom: 14px; color: var(--muted); }
textarea, select {
  width: 100%; font: inherit; color: inherit; padding: 10px 12px;
  border: 1px solid var(--line); border-radius: 10px; background: #fff;
}
select { width: auto; margin-left: 8px; }
textarea:focus, select:focus { outline: 2px solid var(--accent-soft); border-color: var(--accent); }

.row { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; margin-top: 12px; }
.options { justify-content: space-between; margin-bottom: 18px; }
.check { display: flex; align-items: center; gap: 8px; }

button {
  font: inherit; border: 1px solid var(--line); background: #fff; color: var(--text);
  padding: 9px 16px; border-radius: 10px; cursor: pointer;
}
button:disabled { opacity: 0.5; cursor: not-allowed; }
.primary { background: var(--accent); border-color: var(--accent); color: #fff; font-weight: 600; }
.big { width: 100%; padding: 12px; font-size: 17px; }
.ghost { background: transparent; }
.small { padding: 4px 10px; font-size: 13px; }
.mic.rec { background: var(--low); border-color: var(--low); color: #fff; }

.msg { min-height: 1.4em; color: var(--muted); }
.msg.error { color: var(--low); }

.qhead { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
.chip {
  font-size: 12px; padding: 2px 10px; border-radius: 999px;
  background: var(--accent-soft); color: var(--accent);
}
.chip.warn { background: var(--warn-bg); color: var(--mid); }
.answer { margin-top: 16px; }
.live { min-height: 1.4em; color: var(--muted); font-style: italic; margin-top: 4px; }

.eval { margin-top: 16px; padding: 14px 16px; border-radius: 12px; border: 1px solid var(--line); border-left-width: 5px; }
.eval p { margin: 6px 0; }
.eval.s5, .eval.s4 { border-left-color: var(--good); }
.eval.s3 { border-left-color: var(--mid); }
.eval.s2, .eval.s1, .eval.s0 { border-left-color: var(--low); }
.eval-head, .rrow-head { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; }
.score { font-weight: 700; padding: 2px 8px; border-radius: 8px; background: var(--accent-soft); color: var(--accent); }

.trace { margin: 0; padding-left: 20px; font-size: 14px; max-height: 70vh; overflow: auto; }
.trace li { margin-bottom: 8px; }
.trace b { color: var(--accent); }

.score-head { display: flex; gap: 20px; align-items: center; margin-bottom: 12px; }
.big-score { font-size: 48px; font-weight: 800; }
.big-score.good { color: var(--good); }
.big-score.mid { color: var(--mid); }
.big-score.low { color: var(--low); }
.flag-line { color: var(--low); margin: 0; }
.rrow { border-top: 1px solid var(--line); padding: 14px 0; }
.rrow p { margin: 4px 0 6px; }
blockquote {
  margin: 8px 0 0; padding: 8px 12px; background: var(--bg);
  border-left: 3px solid var(--accent); border-radius: 6px; font-size: 14px;
}

footer { text-align: center; color: var(--muted); font-size: 13px; padding: 20px; }

/* settings */
.settings { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 12px 18px; margin: 4px 0 18px; }
.settings label { display: flex; flex-direction: column; gap: 4px; font-size: 14px; color: var(--muted); }
.settings select { margin-left: 0; width: 100%; }
.settings .check { flex-direction: row; align-items: center; color: var(--text); grid-column: 1 / -1; }
.small-text { font-size: 13px; margin-top: 0; }
.error { color: var(--low); }
.empty { padding: 24px; text-align: center; color: var(--muted); border: 2px dashed var(--line); border-radius: 12px; }

/* stat tiles */
.tiles { display: grid; grid-template-columns: repeat(auto-fit, minmax(130px, 1fr)); gap: 12px; margin: 14px 0 6px; }
.tile { border: 1px solid var(--line); border-radius: 12px; padding: 12px 14px; min-width: 0; }
.tile-label { font-size: 13px; color: var(--muted); }
.tile-value { font-size: 22px; font-weight: 600; overflow-wrap: anywhere; }
.tile-value.long { font-size: 15px; padding-top: 5px; }
.tile-note { font-size: 12px; color: var(--muted); }
#analysed .card + .layout, #progress .card + .layout, #progress .layout + .card { margin-top: 20px; }

/* report analysed */
.chunks { padding-left: 0; list-style: none; margin: 0; font-size: 14px; max-height: 420px; overflow: auto; }
.chunks li { padding: 8px 0; border-top: 1px solid var(--line); }
.chunks b { color: var(--accent); margin-right: 6px; }
.plan { padding-left: 22px; margin: 0 0 14px; }
.plan li { padding: 6px 0; font-weight: 600; }

/* viva progress dots */
.dots { display: flex; gap: 8px; margin-bottom: 12px; flex-wrap: wrap; }
.dot { font-size: 12px; padding: 3px 10px; border-radius: 999px; border: 1px solid var(--line); color: var(--muted); }
.dot.now { border-color: var(--accent); color: var(--accent); font-weight: 600; }
.dot.good { background: #e8f6ee; color: var(--good); border-color: transparent; }
.dot.mid { background: var(--warn-bg); color: var(--mid); border-color: transparent; }
.dot.low { background: #fdecec; color: var(--low); border-color: transparent; }
.trace .ms { color: var(--muted); font-size: 12px; white-space: nowrap; }

/* result tabs and transcript */
.tabs { display: flex; gap: 4px; border-bottom: 1px solid var(--line); margin: 16px 0 4px; }
.tabs button { border: none; border-bottom: 2px solid transparent; border-radius: 0; background: none; color: var(--muted); }
.tabs button.active { color: var(--accent); border-bottom-color: var(--accent); font-weight: 600; }
.turn { border-top: 1px solid var(--line); padding: 14px 0; }
.turn p { margin: 2px 0 10px; }
.who { font-size: 12px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.04em; }
.who.examiner { color: var(--accent); }
.who.student { color: var(--muted); }

/* progress chart */
.chart svg { width: 100%; height: auto; display: block; }
.gridline { stroke: var(--line); stroke-width: 1; }
.axis { font-size: 11px; fill: var(--muted); font-variant-numeric: tabular-nums; }
.value { font-size: 12px; font-weight: 600; fill: var(--text); }
.mark { fill: var(--accent); }
.hit { fill: transparent; }
.bar { cursor: default; outline: none; }
.bar:hover .mark, .bar:focus .mark { fill: #6d66ee; }
.tooltip {
  position: absolute; transform: translate(-50%, -100%); pointer-events: none; z-index: 10;
  background: var(--text); color: #fff; padding: 6px 10px; border-radius: 8px; font-size: 12px;
  display: flex; flex-direction: column; gap: 2px; box-shadow: 0 4px 14px rgba(0, 0, 0, 0.15);
}
.tooltip strong { font-size: 15px; }
.meter-row { margin-bottom: 12px; }
.meter-label { display: flex; justify-content: space-between; gap: 8px; font-size: 14px; margin-bottom: 4px; }
.meter { height: 8px; border-radius: 4px; background: #e8f6ee; }
.meter.mid { background: var(--warn-bg); }
.meter.low { background: #fdecec; }
.meter div { height: 100%; border-radius: 4px; background: var(--good); }
.meter.mid div { background: var(--mid); }
.meter.low div { background: var(--low); }
.history { width: 100%; border-collapse: collapse; font-size: 14px; margin-bottom: 12px; }
.history th, .history td { text-align: left; padding: 8px 6px; border-bottom: 1px solid var(--line); }
.history th { color: var(--muted); font-weight: 600; }
.history .num { text-align: right; font-variant-numeric: tabular-nums; }
#historyCard { overflow-x: auto; }

/* How to improve section */
.improve-card { margin-top: 16px; border-left: 4px solid var(--line); }
.improve-card.good { border-left-color: var(--good); }
.improve-card.mid { border-left-color: var(--mid); }
.improve-card.low { border-left-color: var(--low); }
.improve-q { font-weight: 600; margin: 10px 0 8px; font-size: 15px; }
.improve-answer { background: #fafbfc; border: 1px solid var(--line); border-radius: 8px; padding: 8px 12px; font-size: 13.5px; margin-bottom: 12px; color: var(--text); }
.improve-block { margin-top: 10px; padding-top: 10px; border-top: 1px dashed var(--line); }
.improve-title { margin: 0 0 6px; font-size: 12px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.04em; color: var(--muted); }
.improve-title.warn { color: var(--low); }
.improve-title.error { color: var(--low); }
.improve-title.info { color: var(--accent); }
.improve-list { margin: 0 0 6px; padding-left: 20px; font-size: 14px; }
.improve-list li { margin-bottom: 4px; }
.improve-list.error { color: var(--low); }
.improve-text { margin: 0 0 6px; font-size: 14px; color: var(--text); }
#improveSummary { margin-top: 16px; }

/* how it works */
.steps { padding-left: 22px; }
.steps li { margin-bottom: 10px; }
.diagram { width: 100%; max-width: 560px; display: block; margin: 12px auto 20px; }

@media (max-width: 640px) {
  .top { flex-direction: column; align-items: flex-start; gap: 8px; padding: 12px 16px; }
  main { margin: 16px auto; }
  .card { padding: 18px; }
  h1 { font-size: 23px; }
}

@media print {
  .top, footer, button { display: none !important; }
  body { background: #fff; }
  .card { border: none; }
}