:root {
  --ink: #2d3b45;
  --muted: #5c6b74;
  --line: #d3d9de;
  --canvas: #394b58;
  --accent: #0374b5;
  --accent-hover: #025e92;
  --ok: #0a7d3c;
  --bad: #c71f37;
  --bg: #eef2f5;
  --card: #ffffff;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: "Lato", "Helvetica Neue", Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.45;
  min-height: 100vh;
}

.topbar {
  background: var(--canvas);
  color: #fff;
  padding: 12px 20px;
}
.topbar h1 {
  margin: 0;
  font-size: 18px;
  font-weight: 700;
}
.topbar p {
  margin: 2px 0 0;
  font-size: 13px;
  opacity: 0.85;
}

.wrap {
  max-width: 760px;
  margin: 24px auto;
  padding: 0 16px 48px;
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 22px 24px 20px;
  box-shadow: 0 1px 2px rgba(0,0,0,.06);
}

.meta {
  color: var(--muted);
  font-size: 13px;
  margin: 0 0 12px;
}

.progress {
  height: 8px;
  background: #e3e8ec;
  border-radius: 99px;
  overflow: hidden;
  margin: 0 0 18px;
}
.progress > span {
  display: block;
  height: 100%;
  background: var(--accent);
  width: 0;
}

h2 {
  font-size: 18px;
  margin: 0 0 14px;
  font-weight: 700;
}

.figure {
  margin: 0 0 16px;
  padding: 12px;
  background: #f7f9fa;
  border: 1px solid var(--line);
  border-radius: 4px;
  text-align: center;
}
.figure img {
  max-width: 100%;
  height: auto;
  max-height: 340px;
  vertical-align: middle;
}

.choices {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}
.choices label {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 10px 12px;
  cursor: pointer;
  background: #fff;
}
.choices label:hover { border-color: var(--accent); }
.choices input { margin-top: 3px; }
.choices.locked label { cursor: default; }

.choices label.correct {
  border-color: var(--ok);
  background: #eaf7ef;
}
.choices label.wrong {
  border-color: var(--bad);
  background: #fdecee;
}

.why {
  margin: 14px 0 0;
  padding: 10px 12px;
  background: #f4f8fb;
  border-left: 4px solid var(--accent);
  font-size: 14px;
}

.actions {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  margin-top: 18px;
}
button {
  appearance: none;
  border: 0;
  border-radius: 4px;
  padding: 9px 16px;
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
}
button.primary {
  background: var(--accent);
  color: #fff;
}
button.primary:hover { background: var(--accent-hover); }
button.primary:disabled {
  background: #9bb8c9;
  cursor: not-allowed;
}
button.ghost {
  background: #fff;
  color: var(--accent);
  border: 1px solid var(--accent);
}

.score {
  font-size: 28px;
  margin: 8px 0 6px;
}
.score.good { color: var(--ok); }
.score.mid { color: #b36b00; }
.score.low { color: var(--bad); }

.review-item {
  border-top: 1px solid var(--line);
  padding: 14px 0;
}
.review-item h3 {
  font-size: 15px;
  margin: 0 0 8px;
}
.mark-ok { color: var(--ok); font-weight: 700; }
.mark-bad { color: var(--bad); font-weight: 700; }

.note {
  font-size: 13px;
  color: var(--muted);
  margin-top: 16px;
}