@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+KR:wght@400;500;700;900&display=swap');

:root {
  --bg: #0d0d1f;
  --surface: rgba(255,255,255,0.07);
  --border: rgba(255,255,255,0.12);
  --text: #f0f0ff;
  --text-muted: rgba(255,255,255,0.55);
  --radius: 20px;
  --radius-sm: 12px;
  --shadow: 0 8px 32px rgba(0,0,0,0.4);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: 'Noto Sans KR', sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  background-image:
    radial-gradient(ellipse at 20% 50%, rgba(108,99,255,0.15) 0%, transparent 60%),
    radial-gradient(ellipse at 80% 20%, rgba(255,107,157,0.12) 0%, transparent 60%),
    radial-gradient(ellipse at 60% 80%, rgba(0,200,150,0.1) 0%, transparent 60%);
}

#app {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 16px;
  min-height: 100vh;
}

/* ─── Screens ─── */
.screen {
  display: none;
  padding: 40px 0;
  min-height: 100vh;
  animation: fadeIn 0.35s ease;
}
.screen.active { display: block; }

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(18px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ─── SCREEN 1: Topics ─── */
.hero {
  text-align: center;
  margin-bottom: 48px;
}
.hero h1 {
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 900;
  background: linear-gradient(135deg, #a78bfa, #f472b6, #34d399);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -1px;
}
.hero .subtitle {
  margin-top: 10px;
  color: var(--text-muted);
  font-size: 1.05rem;
}

.topics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 18px;
}

.topic-card {
  position: relative;
  border-radius: var(--radius);
  padding: 28px 20px;
  cursor: pointer;
  overflow: hidden;
  transition: transform 0.22s cubic-bezier(.34,1.56,.64,1), box-shadow 0.22s ease;
  border: 1px solid rgba(255,255,255,0.08);
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}
.topic-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(255,255,255,0.07);
  opacity: 0;
  transition: opacity 0.2s;
}
.topic-card:hover { transform: translateY(-6px) scale(1.03); box-shadow: 0 16px 40px rgba(0,0,0,0.5); }
.topic-card:hover::before { opacity: 1; }
.topic-card:active { transform: scale(0.97); }

.topic-icon { font-size: 2.6rem; line-height: 1; }
.topic-name { font-size: 1.1rem; font-weight: 700; color: #fff; }
.topic-count { font-size: 0.78rem; color: rgba(255,255,255,0.65); }

/* ─── SCREEN 2: Count ─── */
.back-btn {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text-muted);
  padding: 8px 16px;
  border-radius: 50px;
  cursor: pointer;
  font-size: 0.9rem;
  transition: all 0.2s;
  font-family: inherit;
}
.back-btn:hover { background: rgba(255,255,255,0.15); color: #fff; }

.count-header {
  text-align: center;
  margin: 48px 0 48px;
}
.count-topic-icon {
  font-size: 3.5rem;
  margin-bottom: 12px;
}
.count-header h2 {
  font-size: 2rem;
  font-weight: 900;
  color: #fff;
}
.count-header p {
  margin-top: 8px;
  color: var(--text-muted);
  font-size: 1.05rem;
}

.count-buttons {
  display: flex;
  gap: 20px;
  justify-content: center;
  flex-wrap: wrap;
}

.count-btn {
  position: relative;
  background: var(--surface);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 36px;
  cursor: pointer;
  color: #fff;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  transition: all 0.25s cubic-bezier(.34,1.56,.64,1);
  font-family: inherit;
  min-width: 140px;
}
.count-btn:hover {
  transform: translateY(-4px);
  border-color: rgba(255,255,255,0.4);
  background: rgba(255,255,255,0.14);
  box-shadow: 0 12px 30px rgba(0,0,0,0.35);
}
.count-btn.featured {
  border-color: #a78bfa;
  background: rgba(167,139,250,0.15);
  box-shadow: 0 0 0 4px rgba(167,139,250,0.12);
}
.count-badge {
  position: absolute;
  top: -12px;
  background: linear-gradient(135deg, #a78bfa, #f472b6);
  padding: 3px 10px;
  border-radius: 50px;
  font-size: 0.72rem;
  font-weight: 700;
  color: #fff;
  letter-spacing: 0.5px;
}
.count-num { font-size: 2.4rem; font-weight: 900; line-height: 1; }
.count-label { font-size: 1rem; font-weight: 600; color: rgba(255,255,255,0.85); }
.count-sub { font-size: 0.78rem; color: var(--text-muted); margin-top: 2px; }

/* ─── SCREEN 3: Quiz ─── */
.quiz-top {
  margin-bottom: 28px;
}
.quiz-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
  font-size: 0.9rem;
}
#quiz-topic-label {
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 4px 12px;
  border-radius: 50px;
  font-size: 0.82rem;
  color: var(--text-muted);
}
#quiz-score-label {
  color: var(--text-muted);
}
#quiz-score-label strong {
  color: #34d399;
  font-size: 1rem;
}
.progress-bar-wrap {
  background: rgba(255,255,255,0.1);
  border-radius: 99px;
  height: 8px;
  overflow: hidden;
}
.progress-bar {
  height: 100%;
  border-radius: 99px;
  background: linear-gradient(90deg, #6C63FF, #f472b6);
  transition: width 0.5s cubic-bezier(.4,0,.2,1);
  width: 0%;
}
.quiz-num {
  text-align: right;
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-top: 6px;
}

.question-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px 32px;
  min-height: 140px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
  backdrop-filter: blur(10px);
  transition: all 0.3s ease;
}
.question-card.correct-flash {
  border-color: #34d399;
  background: rgba(52,211,153,0.1);
}
.question-card.wrong-flash {
  border-color: #f87171;
  background: rgba(248,113,113,0.1);
}
#question-text {
  font-size: clamp(1.05rem, 3vw, 1.3rem);
  font-weight: 600;
  text-align: center;
  line-height: 1.6;
  color: #fff;
}

.answer-area {
  display: flex;
  gap: 12px;
  margin-bottom: 20px;
}
#answer-input {
  flex: 1;
  background: rgba(255,255,255,0.08);
  border: 2px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 14px 20px;
  font-size: 1rem;
  color: #fff;
  font-family: inherit;
  transition: border-color 0.2s;
  outline: none;
}
#answer-input::placeholder { color: rgba(255,255,255,0.3); }
#answer-input:focus { border-color: #a78bfa; background: rgba(255,255,255,0.12); }

#submit-btn {
  background: linear-gradient(135deg, #6C63FF, #a78bfa);
  border: none;
  border-radius: var(--radius-sm);
  padding: 14px 24px;
  color: #fff;
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  font-family: inherit;
  transition: all 0.2s;
  white-space: nowrap;
}
#submit-btn:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(108,99,255,0.4); }
#submit-btn:active { transform: scale(0.96); }

.feedback-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  text-align: center;
  animation: popIn 0.35s cubic-bezier(.34,1.56,.64,1);
  backdrop-filter: blur(10px);
}
.feedback-box.hidden { display: none; }
.feedback-box.correct { border-color: #34d399; background: rgba(52,211,153,0.1); }
.feedback-box.wrong   { border-color: #f87171; background: rgba(248,113,113,0.1); }

@keyframes popIn {
  from { opacity: 0; transform: scale(0.85); }
  to   { opacity: 1; transform: scale(1); }
}

.feedback-icon { font-size: 2.8rem; margin-bottom: 8px; }
.feedback-msg  { font-size: 1.4rem; font-weight: 900; margin-bottom: 8px; }
.feedback-box.correct .feedback-msg { color: #34d399; }
.feedback-box.wrong   .feedback-msg { color: #f87171; }
.correct-answer-hint { font-size: 0.9rem; color: var(--text-muted); margin-bottom: 20px; }
.correct-answer-hint strong { color: #fbbf24; }

.next-btn {
  background: linear-gradient(135deg, #6C63FF, #a78bfa);
  border: none;
  border-radius: var(--radius-sm);
  padding: 12px 28px;
  color: #fff;
  font-size: 0.95rem;
  font-weight: 700;
  cursor: pointer;
  font-family: inherit;
  transition: all 0.2s;
}
.next-btn:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(108,99,255,0.4); }

/* ─── SCREEN 4: Result ─── */
#screen-result {
  display: none;
  align-items: center;
  justify-content: center;
}
#screen-result.active {
  display: flex;
  flex-direction: column;
}

.result-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 28px;
  padding: 48px 40px;
  text-align: center;
  max-width: 480px;
  width: 100%;
  margin: 0 auto;
  backdrop-filter: blur(16px);
  animation: popIn 0.5s cubic-bezier(.34,1.56,.64,1);
}
.result-emoji { font-size: 5rem; margin-bottom: 16px; }
.result-title { font-size: 1.8rem; font-weight: 900; margin-bottom: 24px; color: #fff; }

.result-score-wrap {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 6px;
  margin-bottom: 16px;
}
.result-score {
  font-size: 4rem;
  font-weight: 900;
  background: linear-gradient(135deg, #fbbf24, #f472b6);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
}
.result-total { font-size: 1.4rem; color: var(--text-muted); }

.result-bar-wrap {
  background: rgba(255,255,255,0.1);
  border-radius: 99px;
  height: 10px;
  overflow: hidden;
  margin-bottom: 20px;
}
.result-bar {
  height: 100%;
  border-radius: 99px;
  background: linear-gradient(90deg, #fbbf24, #f472b6);
  transition: width 1s cubic-bezier(.4,0,.2,1);
  width: 0%;
}

.result-msg {
  color: var(--text-muted);
  font-size: 1rem;
  margin-bottom: 32px;
  line-height: 1.6;
}

.result-actions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }

.btn-retry, .btn-home {
  border: none;
  border-radius: var(--radius-sm);
  padding: 13px 28px;
  font-size: 0.95rem;
  font-weight: 700;
  cursor: pointer;
  font-family: inherit;
  transition: all 0.2s;
}
.btn-retry {
  background: linear-gradient(135deg, #6C63FF, #a78bfa);
  color: #fff;
}
.btn-retry:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(108,99,255,0.4); }
.btn-home {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text-muted);
}
.btn-home:hover { background: rgba(255,255,255,0.15); color: #fff; }

/* ─── Confetti ─── */
#confetti-container {
  position: fixed;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
  z-index: 999;
}
.confetti-piece {
  position: absolute;
  width: 10px;
  height: 10px;
  border-radius: 2px;
  animation: confetti-fall linear forwards;
  top: -20px;
}
@keyframes confetti-fall {
  to { transform: translateY(110vh) rotate(720deg); opacity: 0; }
}

/* ─── Responsive ─── */
@media (max-width: 600px) {
  .screen { padding: 24px 0; }
  .topics-grid { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .topic-card { padding: 20px 14px; }
  .topic-icon { font-size: 2rem; }
  .count-buttons { gap: 12px; }
  .count-btn { min-width: 100px; padding: 22px 20px; }
  .question-card { padding: 24px 20px; }
  .answer-area { flex-direction: column; }
  .result-card { padding: 36px 24px; }
}