:root {
  color-scheme: dark;
  --ink: #f8fbff;
  --muted: #a9bdd2;
  --navy: #061422;
  --panel: #0b2138;
  --card: #102f4e;
  --blue: #58aefc;
  --blue-soft: #a5d5ff;
  --green: #34d58a;
  --red: #ff6d7a;
  --line: rgba(255,255,255,.15);
}
* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  font-family: "Segoe UI", system-ui, sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at 10% 0%, rgba(42,123,190,.38), transparent 35%),
    linear-gradient(140deg, #061422, #020811 72%);
}
button { font: inherit; }
.app-shell { min-height: 100vh; display: grid; place-items: center; padding: 24px; }
.stage {
  width: min(96vw, 1440px);
  aspect-ratio: 16 / 9;
  min-height: 650px;
  display: grid;
  grid-template-rows: auto auto 1fr;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: linear-gradient(145deg, rgba(11,33,56,.98), rgba(3,12,23,.99));
  box-shadow: 0 28px 90px rgba(0,0,0,.5);
}
.top-bar { display: flex; justify-content: space-between; gap: 24px; padding: 20px 36px 17px; font-weight: 800; }
.brand { color: var(--blue-soft); }
.progress { flex: 0 0 auto; color: var(--blue); font-variant-numeric: tabular-nums; }
.timer-meter { height: 7px; margin: 0 36px; overflow: hidden; border-radius: 99px; background: rgba(88,174,252,.1); }
.timer-meter div { width: 0; height: 100%; background: linear-gradient(90deg, var(--green), var(--blue)); transition: width .15s linear; }
.timer-meter.paused div { background: #f6bd4d; }
.screen { display: none; padding: 38px 64px; opacity: 0; transform: translateY(10px); }
.screen.active { display: block; animation: enter .35s ease forwards; }
@keyframes enter { to { opacity: 1; transform: none; } }
.intro-screen, .end-screen { align-self: center; max-width: 1180px; }
.eyebrow, .question-meta { margin: 0 0 16px; color: var(--blue-soft); font-size: 20px; font-weight: 900; letter-spacing: .06em; text-transform: uppercase; }
h1 { margin: 0; font-size: clamp(43px, 5vw, 76px); line-height: 1.04; }
h2 { margin: 18px 0 0; color: #deedfb; font-size: clamp(26px, 2.7vw, 42px); line-height: 1.16; }
.subline { margin: 24px 0 12px; color: var(--muted); font-size: clamp(21px, 2vw, 30px); }
.coverage { color: var(--blue-soft); font-size: 18px; font-weight: 750; }
.coverage span { padding: 0 9px; color: var(--green); }
.disclaimer { max-width: 950px; color: var(--muted); line-height: 1.5; }
button {
  border: 1px solid rgba(88,174,252,.45);
  border-radius: 12px;
  padding: 16px 25px;
  background: #126bb9;
  color: white;
  font-size: 20px;
  font-weight: 850;
  cursor: pointer;
}
button:hover, button:focus-visible { background: #1980db; outline: 3px solid rgba(88,174,252,.25); outline-offset: 3px; }
.primary { margin-top: 14px; }
.countdown-badge {
  float: right;
  min-width: 78px;
  margin: 0 0 14px 22px;
  padding: 8px 12px;
  border: 1px solid rgba(165,213,255,.25);
  border-radius: 11px;
  background: rgba(88,174,252,.09);
  color: var(--muted);
  text-align: center;
  font-size: 25px;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}
.question-meta { font-size: 14px; letter-spacing: .08em; }
.quiz-screen h1 { font-size: clamp(30px, 3vw, 48px); line-height: 1.14; }
.options { display: grid; grid-template-columns: 1fr 1fr; gap: 15px; margin-top: 26px; }
.option {
  min-height: 92px;
  display: grid;
  grid-template-columns: 46px 1fr;
  align-items: center;
  gap: 15px;
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: rgba(16,47,78,.75);
  font-size: clamp(18px, 1.55vw, 25px);
  line-height: 1.22;
}
.letter {
  width: 46px; height: 46px; display: grid; place-items: center;
  border: 1px solid rgba(255,255,255,.17); border-radius: 10px;
  background: rgba(88,174,252,.14); color: var(--blue-soft); font-weight: 950;
}
.option.correct { border-color: var(--green); background: rgba(52,213,138,.15); }
.option.correct .letter { background: var(--green); color: #03150c; }
.option.incorrect { border-color: rgba(255,109,122,.68); background: rgba(255,109,122,.09); }
.answer-mode { padding-top: 24px; }
.answer-mode .question-meta { margin-bottom: 8px; }
.answer-mode h1 { font-size: clamp(23px, 2.15vw, 35px); }
.answer-mode .options { gap: 9px; margin-top: 13px; }
.answer-mode .option { min-height: 55px; grid-template-columns: 34px 1fr; gap: 10px; padding: 8px 12px; font-size: clamp(14px, 1.03vw, 17px); }
.answer-mode .letter { width: 34px; height: 34px; border-radius: 8px; }
.answer-panel { margin-top: 13px; padding: 14px 18px; border: 1px solid rgba(52,213,138,.35); border-radius: 14px; background: rgba(4,23,32,.76); }
.answer-panel h2 { margin: 0; color: var(--green); font-size: clamp(18px, 1.45vw, 23px); }
.answer-panel p { margin: 7px 0 10px; font-size: clamp(14px, 1vw, 17px); line-height: 1.35; }
.answer-panel h3 { margin: 0 0 5px; color: var(--blue-soft); font-size: clamp(14px, 1vw, 17px); }
.answer-panel ul { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin: 0; padding: 0; list-style: none; color: var(--muted); font-size: clamp(12px, .86vw, 15px); line-height: 1.25; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0,0,0,0); }
@media (max-width: 850px) {
  .app-shell { padding: 0; }
  .stage { width: 100%; min-height: 100vh; aspect-ratio: auto; border: 0; border-radius: 0; }
  .top-bar { padding: 17px 20px; font-size: 13px; }
  .timer-meter { margin: 0 20px; }
  .screen { padding: 30px 20px; }
  .options { grid-template-columns: 1fr; }
  .answer-panel ul { grid-template-columns: 1fr; }
}