@import url("https://fonts.googleapis.com/css2?family=Figtree:wght@400;600;700;800&display=swap");

:root {
  --bg: #0f1118;
  --card: rgba(17, 22, 35, 0.85);
  --card-border: rgba(127, 90, 240, 0.35);
  --accent: #7f5af0;
  --accent-strong: #9f7aff;
  --accent-soft: rgba(127, 90, 240, 0.1);
  --text: #f5f6ff;
  --muted: #8b8f9e;
  --success: #2cb1bc;
  --danger: #ef4565;
  --warning: #f5b700;
  --radius: 18px;
  --shadow: 0 18px 55px -30px rgba(127, 90, 240, 0.7);
  --transition-fast: 160ms ease;
  --transition-medium: 260ms ease;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  min-height: 100%;
  color: var(--text);
  font-family: "Figtree", system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  background: radial-gradient(circle at top, rgba(127, 90, 240, 0.35), transparent 35%),
    radial-gradient(circle at bottom, rgba(44, 177, 188, 0.25), transparent 45%), var(--bg);
}

a {
  color: inherit;
}

.wrapper {
  width: min(1100px, 92vw);
  margin: 0 auto;
  padding: 40px 0 120px;
}

header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 36px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 16px;
}

.brand img {
  width: 72px;
  height: 72px;
  border-radius: 24px;
  box-shadow: var(--shadow);
}

.brand h1 {
  margin: 0;
  font-size: clamp(1.8rem, 2.6vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -0.02em;
}

.tagline {
  margin: 4px 0 0;
  color: var(--muted);
  font-weight: 500;
}

.mode-switcher {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.mode-btn {
  padding: 12px 20px;
  border-radius: 999px;
  border: 1px solid transparent;
  background: var(--card);
  color: var(--text);
  font-weight: 600;
  cursor: pointer;
  transition: transform var(--transition-fast), border var(--transition-fast), background var(--transition-fast);
}

.mode-btn.active {
  border-color: var(--accent);
  background: linear-gradient(120deg, rgba(127, 90, 240, 0.5), rgba(44, 177, 188, 0.45));
  transform: translateY(-2px);
}

.grid {
  display: grid;
  gap: 24px;
}

.card {
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: clamp(24px, 3vw, 32px);
  box-shadow: var(--shadow);
  backdrop-filter: blur(18px);
}

.card h2 {
  margin: 0 0 16px;
  font-size: clamp(1.4rem, 2vw, 2rem);
}

.question-number {
  color: var(--accent);
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.question-prompt {
  margin: 12px 0 24px;
  font-size: clamp(1.2rem, 2.2vw, 1.6rem);
  font-weight: 700;
}

.choices {
  display: grid;
  gap: 14px;
}

.choice-btn {
  padding: 14px 18px;
  border-radius: var(--radius);
  border: 1px solid rgba(255, 255, 255, 0.04);
  background: rgba(255, 255, 255, 0.02);
  color: inherit;
  font-weight: 600;
  text-align: left;
  cursor: pointer;
  transition: background var(--transition-medium), transform var(--transition-fast), border var(--transition-fast);
}

.choice-btn:hover,
.choice-btn:focus-visible {
  background: rgba(127, 90, 240, 0.12);
  border-color: rgba(127, 90, 240, 0.4);
  transform: translateY(-2px);
}

.choice-btn.correct {
  border-color: rgba(44, 177, 188, 0.6);
  background: rgba(44, 177, 188, 0.12);
}

.choice-btn.incorrect {
  border-color: rgba(239, 69, 101, 0.6);
  background: rgba(239, 69, 101, 0.12);
}

.status-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 24px;
  color: var(--muted);
  font-size: 0.95rem;
}

.pill {
  padding: 6px 12px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--text);
  font-weight: 600;
}

.primary-action {
  margin-top: 28px;
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 12px 22px;
  border-radius: 14px;
  border: none;
  background: var(--accent);
  color: white;
  font-weight: 700;
  cursor: pointer;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.primary-action:hover,
.primary-action:focus-visible {
  transform: translateY(-2px);
  box-shadow: 0 14px 30px -18px rgba(127, 90, 240, 0.9);
}

.flashcard {
  position: relative;
  min-height: 220px;
  display: grid;
  place-items: center;
  text-align: center;
  padding: 40px 24px;
  border-radius: var(--radius);
  background: linear-gradient(160deg, rgba(127, 90, 240, 0.3), rgba(44, 177, 188, 0.25));
  border: 1px solid rgba(255, 255, 255, 0.12);
}

.flashcard .code {
  font-size: clamp(3.2rem, 8vw, 4.5rem);
  font-weight: 800;
}

.flashcard .label {
  margin-top: 10px;
  color: var(--muted);
  font-weight: 600;
  letter-spacing: 0.12em;
}

.flashcard .answer {
  margin-top: 22px;
  font-size: clamp(1.2rem, 3vw, 1.8rem);
  font-weight: 700;
}

.flashcard .meta {
  margin-top: 10px;
  font-size: 0.95rem;
  color: var(--muted);
}

.flashcard-controls {
  margin-top: 24px;
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

.flashcard-controls button {
  padding: 12px 20px;
  border-radius: var(--radius);
  border: 1px solid transparent;
  background: rgba(255, 255, 255, 0.05);
  color: var(--text);
  font-weight: 600;
  cursor: pointer;
  transition: transform var(--transition-fast), border var(--transition-fast), background var(--transition-fast);
}

.flashcard-controls button.primary {
  background: var(--accent);
}

.flashcard-controls button.success {
  background: rgba(44, 177, 188, 0.12);
  border-color: rgba(44, 177, 188, 0.4);
}

.flashcard-controls button.danger {
  background: rgba(239, 69, 101, 0.12);
  border-color: rgba(239, 69, 101, 0.4);
}

.exam-progress {
  margin: 20px 0;
  height: 12px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: 999px;
  overflow: hidden;
}

.exam-progress span {
  display: block;
  height: 100%;
  background: linear-gradient(120deg, rgba(127, 90, 240, 0.9), rgba(44, 177, 188, 0.9));
  border-radius: inherit;
}

.exam-summary {
  display: grid;
  gap: 12px;
  margin-top: 24px;
}

.exam-summary .score {
  font-size: clamp(1.8rem, 3vw, 2.4rem);
  font-weight: 800;
}

.exam-summary .detail {
  color: var(--muted);
}

/* Exam recap list */
.exam-recap {
  list-style: none;
  padding: 0;
  margin: 14px 0 6px;
  display: grid;
  gap: 10px;
}
.exam-recap .recap-item {
  display: grid;
  grid-template-columns: 36px 70px 1fr auto;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-left-width: 4px;
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.03);
}
.exam-recap .recap-item.correct { border-left-color: var(--success); }
.exam-recap .recap-item.incorrect { border-left-color: var(--danger); }
.exam-recap .recap-item .index { color: var(--muted); font-weight: 700; }
.exam-recap .recap-item .code { font-weight: 800; }
.exam-recap .recap-item .name { opacity: 0.9; }
.exam-recap .recap-item .mark { font-size: 1.1rem; }
.exam-recap .recap-item .user-answer {
  grid-column: 1 / -1;
  margin-top: 6px;
  color: var(--muted);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 18px;
}

.stat-card {
  padding: 22px;
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.stat-card h3 {
  margin: 0;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--muted);
}

.stat-card .value {
  margin-top: 12px;
  font-size: 2rem;
  font-weight: 800;
}

.stat-card .trend {
  margin-top: 6px;
  color: var(--accent);
  font-weight: 600;
}

.toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.toolbar button {
  padding: 10px 18px;
  border-radius: var(--radius);
  border: 1px solid rgba(255, 255, 255, 0.1);
  background: rgba(255, 255, 255, 0.02);
  color: var(--text);
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition-medium), border var(--transition-medium);
}

.toolbar button:hover,
.toolbar button:focus-visible {
  background: rgba(127, 90, 240, 0.15);
  border-color: rgba(127, 90, 240, 0.4);
}

.hidden {
  display: none !important;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

@media (max-width: 840px) {
  header {
    flex-direction: column;
    align-items: flex-start;
  }

  .brand img {
    width: 64px;
    height: 64px;
  }

  .wrapper {
    padding-top: 32px;
  }
}

@media (max-width: 560px) {
  .mode-switcher {
    width: 100%;
  }

  .mode-btn {
    flex: 1 1 auto;
    text-align: center;
  }

  .flashcard {
    padding: 32px 20px;
  }

  .toolbar {
    flex-direction: column;
  }

  .toolbar button {
    width: 100%;
    justify-content: center;
  }
}