.quiz-screen {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  z-index: 1;
  padding: 6rem 1.5rem 3rem;
}

.quiz-screen.hidden { display: none; }

.quiz-start-inner {
  max-width: 600px;
  text-align: center;
  animation: fadeInUp 0.8s ease both;
}

.quiz-badge {
  display: inline-block;
  padding: 0.4rem 1.2rem;
  background: var(--green-glow);
  border: 1px solid var(--border);
  border-radius: 50px;
  font-size: 0.85rem;
  color: var(--green);
  margin-bottom: 1.5rem;
}

.quiz-title {
  font-size: clamp(3rem,7vw,5rem);
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 1rem;
}

.quiz-title em { color: var(--green); font-style: italic; }
.quiz-desc { color: var(--text-muted); font-size: 1.05rem; margin-bottom: 2rem; }

.quiz-info-row {
  display: flex;
  justify-content: center;
  gap: 2rem;
  margin-bottom: 2rem;
}

.quiz-info-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.difficulty-select { margin-bottom: 2.5rem; }

.diff-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 0.75rem;
  font-family: 'Space Mono', monospace;
}

.diff-btns { display: flex; gap: 0.75rem; justify-content: center; }

.diff-btn {
  padding: 0.5rem 1.2rem;
  background: var(--glass);
  border: 1px solid var(--border);
  border-radius: 50px;
  color: var(--text-muted);
  font-family: 'Plus Jakarta Sans', sans-serif;
  font-size: 0.85rem;
  cursor: pointer;
  transition: var(--transition);
}

.diff-btn.active,
.diff-btn[aria-checked="true"],
.diff-btn:hover {
  background: var(--green-glow);
  color: var(--green);
  border-color: var(--green);
}

.diff-btn:focus {
  outline: 2px solid var(--green);
  outline-offset: 2px;
}

.quiz-start-btn { font-size: 1rem; padding: 1rem 2.5rem; }

/* ACTIVE */
.quiz-active-inner { width: 100%; max-width: 700px; }

.quiz-top-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.75rem;
}

.quiz-progress-text {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-family: 'Space Mono', monospace;
}

.quiz-score-display {
  font-size: 0.85rem;
  color: var(--green);
  font-family: 'Space Mono', monospace;
}

.quiz-timer {
  width: 46px; height: 46px;
  background: var(--green-glow);
  border: 2px solid var(--green);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'Space Mono', monospace;
  font-size: 1rem;
  font-weight: 700;
  color: var(--green);
  transition: all 0.3s;
}

.quiz-timer.urgent {
  background: rgba(239,68,68,0.2);
  border-color: #ef4444;
  color: #ef4444;
  animation: timerPulse 0.5s infinite;
}

@keyframes timerPulse {
  0%,100% { transform: scale(1); }
  50%      { transform: scale(1.1); }
}

.quiz-progress-bar {
  height: 4px;
  background: rgba(255,255,255,0.1);
  border-radius: 2px;
  margin-bottom: 2rem;
  overflow: hidden;
}

.quiz-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--green-muted), var(--green));
  border-radius: 2px;
  transition: width 0.4s ease;
}

.question-card {
  background: var(--glass);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2.5rem;
  margin-bottom: 1.5rem;
  animation: fadeInUp 0.4s ease;
}

.q-category {
  font-size: 0.7rem;
  font-family: 'Space Mono', monospace;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--green);
  margin-bottom: 1rem;
}

.q-text {
  font-size: clamp(1.1rem,2.5vw,1.4rem);
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 2rem;
}

.options-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
}

.option-btn {
  padding: 0.9rem 1.2rem;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-family: 'Plus Jakarta Sans', sans-serif;
  font-size: 0.9rem;
  cursor: pointer;
  transition: var(--transition);
  text-align: left;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  line-height: 1.4;
}

.option-btn:hover:not(:disabled) {
  border-color: var(--green);
  background: var(--green-glow);
  transform: translateY(-1px);
}

.option-btn:focus {
  outline: 2px solid var(--green);
  outline-offset: 2px;
}

.option-btn.correct {
  background: rgba(34,197,94,0.15);
  border-color: #22c55e;
  color: #22c55e;
}

.option-btn.wrong {
  background: rgba(239,68,68,0.15);
  border-color: #ef4444;
  color: #ef4444;
}

.option-label {
  width: 26px; height: 26px;
  background: var(--border);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-family: 'Space Mono', monospace;
  font-weight: 700;
  flex-shrink: 0;
}

.quiz-nav { display: flex; justify-content: flex-end; }

.quiz-skip-btn {
  background: none;
  border: 1px solid var(--border);
  color: var(--text-muted);
  padding: 0.5rem 1.2rem;
  border-radius: 50px;
  font-family: 'Plus Jakarta Sans', sans-serif;
  font-size: 0.85rem;
  cursor: pointer;
  transition: var(--transition);
}

.quiz-skip-btn:hover { border-color: var(--green); color: var(--green); }
.quiz-skip-btn:focus { outline: 2px solid var(--green); outline-offset: 2px; }

/* RESULT */
.quiz-result-inner { text-align: center; max-width: 500px; animation: fadeInUp 0.8s ease; }
.result-emoji { font-size: 4rem; margin-bottom: 0.5rem; }
.result-grade { font-size: 2.5rem; font-weight: 800; color: var(--green); margin-bottom: 2rem; }

.result-score-ring { position: relative; width: 160px; margin: 0 auto 1.5rem; }
.score-ring-svg { width: 100%; }

.score-ring-text {
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%,-50%);
  text-align: center;
}

.score-num { font-size: 2.5rem; font-weight: 800; color: var(--green); display: block; }
.score-denom { font-size: 0.9rem; color: var(--text-muted); }
.result-message { color: var(--text-muted); margin-bottom: 1.5rem; }

.result-breakdown {
  background: var(--glass);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  text-align: left;
  margin-bottom: 2rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.breakdown-row {
  display: flex;
  justify-content: space-between;
  font-size: 0.9rem;
}

.breakdown-row span:last-child { font-weight: 600; color: var(--green); }
.result-actions { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }

@media (max-width:600px) {
  .options-grid { grid-template-columns: 1fr; }
  .quiz-info-row { gap: 1rem; }
}