:root {
  --bg: #14161A;
  --bg-elev: #1E2128;
  --bg-elev-2: #262A33;
  --yellow: #FFC300;
  --yellow-dim: #B38F00;
  --red: #E63946;
  --green: #3DDC97;
  --text: #F2F2F0;
  --text-dim: #9AA0AC;
  --radius: 14px;
  --font-display: 'Oswald', sans-serif;
  --font-body: 'Inter', system-ui, sans-serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  -webkit-tap-highlight-color: transparent;
}

/* Сигнатурный элемент: полоса предупреждающей разметки */
.stripe-bar {
  height: 6px;
  width: 100%;
  background: repeating-linear-gradient(135deg, var(--yellow) 0 14px, #14161A 14px 28px);
}

#app {
  max-width: 480px;
  margin: 0 auto;
  padding: 28px 20px 40px;
  min-height: 100vh;
}

.screen { display: none; animation: fadeIn .25s ease; }
.screen.active { display: block; }

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

.badge {
  display: inline-block;
  font-family: var(--font-display);
  font-size: 12px;
  letter-spacing: .12em;
  font-weight: 600;
  color: #14161A;
  background: var(--yellow);
  padding: 5px 10px;
  border-radius: 4px;
  margin-bottom: 16px;
}

h1 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 30px;
  line-height: 1.15;
  margin: 0 0 12px;
}

h2 {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: 22px;
  line-height: 1.3;
  margin: 20px 0 20px;
}

.lead {
  color: var(--text-dim);
  font-size: 15px;
  line-height: 1.5;
  margin: 0 0 28px;
}

.hint { color: var(--text-dim); font-size: 13px; margin-top: 16px; }

.btn {
  width: 100%;
  border: none;
  border-radius: var(--radius);
  padding: 15px 18px;
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 16px;
  cursor: pointer;
  transition: transform .12s ease, opacity .12s ease;
}
.btn:active { transform: scale(.98); }
.btn-primary { background: var(--yellow); color: #14161A; }
.btn-ghost {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--bg-elev-2);
  margin-top: 10px;
}

.progress-track {
  height: 6px;
  border-radius: 3px;
  background: var(--bg-elev);
  overflow: hidden;
  margin-bottom: 14px;
}
.progress-fill {
  height: 100%;
  width: 0%;
  background: repeating-linear-gradient(135deg, var(--yellow) 0 8px, var(--yellow-dim) 8px 16px);
  transition: width .3s ease;
}

.quiz-meta {
  display: flex;
  justify-content: space-between;
  font-size: 13px;
  color: var(--text-dim);
  font-family: var(--font-display);
  letter-spacing: .04em;
}

.options { display: flex; flex-direction: column; gap: 10px; }

.option {
  text-align: left;
  background: var(--bg-elev);
  border: 1px solid var(--bg-elev-2);
  color: var(--text);
  border-radius: var(--radius);
  padding: 14px 16px;
  font-size: 15px;
  font-family: inherit;
  cursor: pointer;
  transition: border-color .15s ease, background .15s ease;
}
.option:active { transform: scale(.99); }
.option.correct { border-color: var(--green); background: rgba(61,220,151,.12); }
.option.wrong { border-color: var(--red); background: rgba(230,57,70,.12); }
.option.disabled { pointer-events: none; opacity: .85; }

.explanation {
  margin-top: 16px;
  padding: 14px 16px;
  border-radius: var(--radius);
  background: var(--bg-elev);
  color: var(--text-dim);
  font-size: 14px;
  line-height: 1.5;
}

.hidden { display: none; }

.result-actions { margin-top: 8px; }

#resultScore { font-family: var(--font-display); font-size: 44px; margin-bottom: 8px; }

@media (min-width: 520px) {
  #app { padding-top: 48px; }
}