:root {
  color-scheme: light dark;
  --page: #f5f7fa;
  --card: #fff;
  --text: #182b3b;
  --muted: #526574;
  --border: #cbd5de;
  --accent: #156b70;
  --hover: #f0f7f7;
  --good: #166344;
  --good-bg: #edf8f1;
  --bad: #a12d35;
  --bad-bg: #fff1f1;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  padding: 48px 20px;
  background: var(--page);
  color: var(--text);
  font: 17px/1.6 system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
.question-card { --card-gutter: 40px; max-width: 720px; margin: 0 auto; }
.question-header, .question-panel { border: 1px solid var(--border); border-radius: 20px; background: var(--card); box-shadow: 0 12px 40px #182b3b08; }
.question-header { display: flex; flex-direction: column; align-items: center; justify-content: center; overflow: hidden; margin-bottom: 12px; padding: 24px var(--card-gutter) 16px; }
.question-panel { padding: 24px var(--card-gutter) 32px; }
h1 { width: fit-content; margin: 0; color: var(--text); line-height: 1; text-align: center; }
.question-logo { position: relative; display: block; padding: 0 22px 4px; color: var(--accent); font-family: "Caudex", Georgia, serif; font-size: clamp(2.6rem, 9vw, 3.7rem); font-weight: 700; line-height: 1.15; letter-spacing: -.035em; white-space: nowrap; }
.title-subtitle { display: flex; align-items: center; justify-content: center; gap: 6px; margin-top: 2px; color: var(--muted); font-size: .75rem; font-weight: 650; line-height: 1.5; letter-spacing: .16em; text-transform: uppercase; }
.title-subtitle::before, .title-subtitle::after { content: ""; width: 24px; height: 1px; margin: 0 5px; background: var(--border); }
.question-date { display: block; width: calc(100% + 2 * var(--card-gutter)); margin-top: 12px; margin-bottom: -16px; margin-inline: calc(-1 * var(--card-gutter)); padding: 4px var(--card-gutter); border-top: 1px solid var(--border); background: var(--hover); color: var(--accent); text-align: center; font-size: .75rem; font-weight: 550; line-height: 1.35; font-variant-numeric: tabular-nums; letter-spacing: .03em; }
fieldset { min-width: 0; padding: 0; margin: 0; border: 0; }
legend { width: 100%; padding: 0; margin-bottom: 24px; font-size: 1.13rem; font-weight: 550; }
.choices { display: grid; gap: 12px; }
.choice {
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr);
  align-items: center;
  gap: 12px;
  width: 100%;
  padding: 16px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--card);
  color: var(--text);
  text-align: left;
  font: inherit;
  cursor: pointer;
  overflow-wrap: anywhere;
}
.choice:not([aria-disabled]):hover { border-color: var(--accent); background: var(--hover); }
.choice-letter { display: grid; place-items: center; width: 30px; min-height: 30px; border: 1px solid currentColor; border-radius: 50%; color: var(--muted); font-size: .8rem; font-weight: 650; }
.choice[aria-disabled] { cursor: default; }
.choice.is-correct { border-color: var(--good); background: var(--good-bg); }
.choice.is-incorrect { border-color: var(--bad); background: var(--bad-bg); }
.choice-status { grid-column: 2; font-size: .86rem; font-weight: 650; }
.is-correct .choice-status { color: var(--good); }
.is-incorrect .choice-status { color: var(--bad); }
.feedback { margin-top: 28px; padding: 22px; border-left: 4px solid; border-radius: 0 12px 12px 0; scroll-margin: 20px; }
.feedback.correct { border-color: var(--good); background: var(--good-bg); }
.feedback.incorrect { border-color: var(--bad); background: var(--bad-bg); }
h2 { display: flex; align-items: center; gap: 12px; margin: 0 0 16px; font-size: 1.15rem; }
.correct h2 { color: var(--good); }
.incorrect h2 { color: var(--bad); }
p { margin: 0; }
.references { display: flex; flex-wrap: wrap; align-items: center; justify-content: center; gap: 8px 12px; margin-top: 28px; padding-top: 20px; border-top: 1px solid var(--border); font-size: .9rem; color: var(--muted); }
.reference-pill { display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 8px 16px; border: 1px solid var(--border); border-radius: 999px; background: var(--page); color: var(--muted); font-weight: 650; }
.reference-link { min-height: 44px; border-color: var(--accent); background: var(--hover); color: var(--accent); text-decoration: none; }
.reference-link:hover { background: var(--page); color: var(--accent); }
a:focus-visible, button:focus-visible { outline: 3px solid var(--accent); outline-offset: 4px; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; border: 0; }
[hidden] { display: none !important; }
@media (max-width: 540px) {
  body { padding: 20px 12px; }
  .question-card { --card-gutter: 18px; }
  .question-header, .question-panel { border-radius: 16px; }
  .question-header { padding-top: 20px; }
  .question-panel { padding: 18px var(--card-gutter) 26px; }
  .choice { padding: 14px 12px; gap: 10px; }
  .feedback { padding: 18px 16px; }
}
@media (prefers-color-scheme: dark) {
  :root { --page: #101a23; --card: #182630; --text: #e7eef3; --muted: #b1c2cf; --border: #455966; --accent: #80d4cf; --hover: #20383d; --good: #8ee0b2; --good-bg: #193b30; --bad: #ffb1b6; --bad-bg: #40272d; }
}

.answer-animation { display: inline-flex; flex: 0 0 48px; width: 48px; height: 48px; transform-origin: center; }
.answer-animation svg { display: block; width: 100%; height: 100%; overflow: visible; stroke: currentColor; stroke-width: 3; stroke-linecap: round; stroke-linejoin: round; }
.answer-ring { stroke-width: 2; opacity: .45; }
.answer-check, .answer-cross { display: none; stroke-dasharray: 48; stroke-dashoffset: 0; }
.correct .answer-check, .incorrect .answer-cross { display: block; }
.celebration { position: fixed; inset: 0; display: grid; place-items: center; pointer-events: none; z-index: 50; overflow: hidden; }
.confetti { position: absolute; left: 50%; top: 50%; margin: -6.5px 0 0 -4px; width: 8px; height: 13px; border-radius: 2px; animation: confetti 1.1s ease-out forwards; }
.celebration-badge { position: relative; width: 120px; height: 120px; border-radius: 50%; color: var(--card); display: grid; place-items: center; box-shadow: 0 8px 35px #0002; }
.celebration-badge svg { width: 64px; height: 64px; }
.celebration-correct { background: var(--good); animation: check-pop 1.1s ease both; }
.celebration-incorrect { width: 156px; height: 156px; background: var(--bad); animation: cross-pop 1.1s ease both; }
.celebration-incorrect svg { width: 88px; height: 88px; }
@keyframes confetti { 0% { transform: translate(0,0) rotate(0); opacity: 0; } 12% { opacity: 1; } 100% { transform: translate(var(--x),var(--y)) rotate(var(--r)); opacity: 0; } }
@keyframes check-pop { 0% { opacity: 0; transform: scale(.5); } 20% { opacity: 1; transform: scale(1.1); } 40%, 70% { opacity: 1; transform: scale(1); } 100% { opacity: 0; transform: scale(.95); } }
@keyframes cross-pop { 0% { opacity: 0; transform: scale(.5); } 20% { opacity: 1; transform: scale(1.1); } 30%, 50% { opacity: 1; transform: rotate(-8deg); } 40%, 60% { opacity: 1; transform: rotate(8deg); } 70% { opacity: 1; transform: scale(1); } 100% { opacity: 0; transform: scale(.95); } }
@media (prefers-reduced-motion: reduce) {
  .celebration { display: none; }
  .celebration * { animation: none !important; }
}

.answer-instruction { margin: -12px 0 18px; color: var(--muted); font-size: .9rem; }
.choice-checkbox { width: 22px; height: 22px; margin: 0 auto; accent-color: var(--accent); }
.choice-checkbox:focus-visible { outline: 3px solid var(--accent); outline-offset: 4px; }
.check-answer { width: 100%; margin-top: 18px; min-height: 48px; padding: 12px 18px; border: 1px solid var(--accent); border-radius: 12px; background: var(--accent); color: var(--card); font: inherit; font-weight: 650; cursor: pointer; }
.check-answer:disabled { opacity: .55; cursor: default; }
.feedback.review { border-color: var(--accent); background: var(--hover); }
.partial-note { margin-bottom: 16px; color: var(--muted); font-size: .9rem; }
.submit-status:empty { display: none; }
.submit-status { margin-top: 16px; color: var(--muted); font-size: .9rem; }
.page-message { text-align: center; padding: 20px 0; }