/* PART 2: Insert full CSS from Part 2 here */
    :root {
  --bg-gradient-start: #0f172a;
  --bg-gradient-end: #020617;
  --accent: #38bdf8;
  --accent-soft: rgba(56, 189, 248, 0.12);
  --accent-strong: #0ea5e9;
  --danger: #f87171;
  --success: #4ade80;
  --card-bg: rgba(15, 23, 42, 0.96);
  --card-border: rgba(148, 163, 184, 0.2);
  --card-bg-secondary: rgba(15, 23, 42, 0.85);
  --text-main: #e5e7eb;
  --text-soft: #9ca3af;
  --text-muted: #6b7280;
  --shadow-soft: 0 18px 45px rgba(15, 23, 42, 0.85);
  --radius-lg: 18px;
  --radius-pill: 999px;
  --transition-fast: 0.18s ease-out;
  --transition-med: 0.22s ease-out;
  --border-subtle: 1px solid var(--card-border);
  --font-main: system-ui, -apple-system, BlinkMacSystemFont, "SF Pro Text",
    "Segoe UI", sans-serif;
}

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

html,
body {
  margin: 0;
  padding: 0;
  min-height: 100%;
}

body {
  font-family: var(--font-main);
  background: radial-gradient(circle at top left, #1e3a8a, transparent 55%),
    radial-gradient(circle at bottom right, #0f766e, transparent 55%),
    linear-gradient(135deg, var(--bg-gradient-start), var(--bg-gradient-end));
  color: var(--text-main);
}

/* Layout */

.app-wrapper {
  min-height: 100vh;
  display: flex;
  align-items: stretch;
  justify-content: center;
  padding: 24px 16px;
}

.app-shell {
  width: 100%;
  max-width: 1120px;
  background: radial-gradient(circle at top, rgba(56, 189, 248, 0.25), transparent 60%),
    linear-gradient(145deg, rgba(15, 23, 42, 0.96), rgba(15, 23, 42, 0.96));
  border-radius: 26px;
  border: 1px solid rgba(148, 163, 184, 0.4);
  box-shadow: var(--shadow-soft);
  padding: 18px 18px 24px;
  position: relative;
  overflow: hidden;
}

.app-shell::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 15% 0%, rgba(96, 165, 250, 0.22), transparent 50%),
    radial-gradient(circle at 85% 100%, rgba(45, 212, 191, 0.18), transparent 50%);
  pointer-events: none;
  mix-blend-mode: soft-light;
  opacity: 0.9;
}

.app-header,
.app-main {
  position: relative;
  z-index: 1;
}

/* Header */

.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 4px 4px 10px;
  border-bottom: 1px solid rgba(148, 163, 184, 0.35);
  margin-bottom: 10px;
}

.app-title-group {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.app-title {
  margin: 0;
  font-size: 1.1rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: #e5e7eb;
}

.app-subtitle {
  margin: 0;
  font-size: 0.9rem;
  color: var(--text-soft);
}

.app-badge {
  border-radius: var(--radius-pill);
  padding: 6px 14px;
  font-size: 0.8rem;
  border: 1px solid rgba(56, 189, 248, 0.7);
  background: radial-gradient(circle at top, rgba(56, 189, 248, 0.26), transparent 60%),
    rgba(15, 23, 42, 0.85);
  color: #e0f2fe;
}

/* Main layout */

.app-main {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 4px;
}

/* Cards */

.card {
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  border: var(--border-subtle);
  box-shadow: 0 18px 40px rgba(15, 23, 42, 0.75);
  padding: 18px 18px 16px;
  backdrop-filter: blur(20px);
}

.card-secondary {
  background: var(--card-bg-secondary);
}

.card h2,
.card h3 {
  margin-top: 0;
}

.card h2 {
  font-size: 1.25rem;
  margin-bottom: 4px;
}

.card h3 {
  font-size: 1.02rem;
  margin-bottom: 4px;
}

.card-section {
  margin-top: 12px;
  border-top: 1px dashed rgba(148, 163, 184, 0.35);
  padding-top: 10px;
}

.card-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 14px;
}

/* Text helpers */

.lead {
  margin: 4px 0 10px;
  color: var(--text-soft);
  font-size: 0.95rem;
}

.hint {
  margin: 2px 0 6px;
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* Buttons */

.btn {
  border-radius: var(--radius-pill);
  padding: 8px 16px;
  font-size: 0.9rem;
  border: none;
  cursor: pointer;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast),
    background var(--transition-fast), border-color var(--transition-fast),
    color var(--transition-fast);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  font-weight: 500;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-strong), #22c55e);
  color: #ecfeff;
  box-shadow: 0 12px 25px rgba(8, 47, 73, 0.6);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 16px 35px rgba(8, 47, 73, 0.75);
}

.btn-outline {
  background: transparent;
  border: 1px solid rgba(148, 163, 184, 0.7);
  color: var(--text-main);
}

.btn-outline:hover {
  border-color: var(--accent-strong);
  background: rgba(15, 23, 42, 0.95);
}

.btn-ghost {
  background: transparent;
  color: var(--text-soft);
}

.btn-ghost:hover {
  background: rgba(15, 23, 42, 0.6);
  color: var(--text-main);
}

/* Timer pills */

.timer-options {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.pill-option {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  border-radius: var(--radius-pill);
  padding: 6px 12px;
  border: 1px solid rgba(148, 163, 184, 0.5);
  background: rgba(15, 23, 42, 0.8);
  cursor: pointer;
  font-size: 0.85rem;
  color: var(--text-soft);
  transition: border-color var(--transition-fast), background var(--transition-fast),
    box-shadow var(--transition-fast), color var(--transition-fast);
}

.pill-option input {
  accent-color: var(--accent-strong);
}

.pill-option:hover {
  border-color: var(--accent-strong);
  color: var(--text-main);
}

.pill-option input:checked + span,
.pill-option input:checked ~ span {
  color: #e0f2fe;
}

/* Feature list */

.feature-list {
  margin: 4px 0 0;
  padding-left: 18px;
  color: var(--text-soft);
  font-size: 0.9rem;
}

.feature-list li {
  margin: 2px 0;
}

/* Views */

.view {
  display: none;
  animation: fadeInUp 0.28s var(--transition-med);
}

.view-active {
  display: block;
}

.view-hidden {
  display: none;
}

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

/* Quiz header */

.quiz-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.quiz-header-left h2 {
  margin: 0;
  font-size: 1.08rem;
}

.quiz-header-left .hint {
  margin-top: 2px;
}

/* Timer display */

.timer-display {
  border-radius: var(--radius-pill);
  padding: 6px 10px;
  background: radial-gradient(circle at top, rgba(56, 189, 248, 0.3), transparent 70%),
    rgba(15, 23, 42, 0.9);
  border: 1px solid rgba(56, 189, 248, 0.7);
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
}

.timer-hidden {
  display: none;
}

.timer-label {
  font-size: 0.75rem;
  color: #bae6fd;
}

.timer-value {
  font-family: "SF Mono", ui-monospace, Menlo, Monaco, Consolas, "Liberation Mono",
    "Courier New", monospace;
  font-size: 0.95rem;
}

/* Progress bar */

.progress-bar {
  margin-top: 10px;
  height: 6px;
  border-radius: var(--radius-pill);
  background: rgba(15, 23, 42, 0.9);
  border: 1px solid rgba(30, 64, 175, 0.55);
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--accent), #22c55e);
  transition: width 0.25s ease-out;
}

/* Quiz card */

.quiz-card {
  margin-top: 10px;
}

.quiz-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 6px;
}

.question-type-label {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  border-radius: var(--radius-pill);
  background: rgba(15, 23, 42, 0.95);
  border: 1px solid rgba(148, 163, 184, 0.65);
  font-size: 0.78rem;
  color: var(--text-soft);
}

.question-text {
  font-size: 1rem;
  margin: 6px 0 10px;
}

/* Options */

.options-container {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.option-item {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  padding: 8px 10px;
  border-radius: 12px;
  background: rgba(15, 23, 42, 0.9);
  border: 1px solid rgba(51, 65, 85, 0.9);
  cursor: pointer;
  transition: border-color var(--transition-fast), background var(--transition-fast),
    transform var(--transition-fast), box-shadow var(--transition-fast);
}

.option-item input {
  margin-top: 3px;
  accent-color: var(--accent-strong);
}

.option-label-text {
  font-size: 0.92rem;
  color: var(--text-main);
}

.option-item:hover {
  border-color: var(--accent-strong);
  box-shadow: 0 10px 20px rgba(15, 23, 42, 0.7);
  transform: translateY(-1px);
}

/* Quiz navigation */

.quiz-nav {
  margin-top: 10px;
  display: flex;
  align-items: center;
  gap: 10px;
  justify-content: space-between;
}

.quiz-nav-center {
  flex: 1;
  display: flex;
  justify-content: center;
}

.quiz-nav-right {
  display: flex;
  gap: 6px;
}

/* Results */

.results-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 10px;
}

.stat-pill {
  border-radius: 14px;
  padding: 8px 12px;
  background: rgba(15, 23, 42, 0.9);
  border: 1px solid rgba(148, 163, 184, 0.65);
  min-width: 100px;
}

.stat-label {
  display: block;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.stat-value {
  display: block;
  font-size: 0.98rem;
  margin-top: 2px;
}

/* Attempt history */

.attempt-history {
  margin-top: 8px;
  font-size: 0.88rem;
}

.attempt-history-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.86rem;
}

.attempt-history-table th,
.attempt-history-table td {
  padding: 6px 8px;
  text-align: left;
}

.attempt-history-table th {
  color: var(--text-soft);
  font-weight: 500;
  border-bottom: 1px solid rgba(55, 65, 81, 0.9);
}

.attempt-history-table tr:nth-child(even) td {
  background: rgba(15, 23, 42, 0.8);
}

.attempt-history-table td {
  border-bottom: 1px dashed rgba(31, 41, 55, 0.8);
}

.empty-state {
  color: var(--text-muted);
}

/* Results breakdown cards */

.results-container {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 8px;
}

.result-question-card {
  border-radius: 12px;
  padding: 8px 10px;
  border: 1px solid rgba(51, 65, 85, 0.9);
  background: rgba(15, 23, 42, 0.94);
  font-size: 0.9rem;
}

.result-question-card.correct {
  border-color: rgba(74, 222, 128, 0.9);
  box-shadow: 0 0 0 1px rgba(74, 222, 128, 0.4);
}

.result-question-card.incorrect {
  border-color: rgba(248, 113, 113, 0.9);
  box-shadow: 0 0 0 1px rgba(248, 113, 113, 0.4);
}

.result-question-header {
  display: flex;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 4px;
}

.result-badge {
  border-radius: var(--radius-pill);
  padding: 2px 8px;
  font-size: 0.7rem;
  text-transform: uppercase;
}

.result-badge.correct {
  background: rgba(22, 163, 74, 0.22);
  color: #bbf7d0;
}

.result-badge.incorrect {
  background: rgba(220, 38, 38, 0.24);
  color: #fecaca;
}

.result-question-text {
  margin: 0 0 4px;
}

.result-answer-line {
  margin: 1px 0;
  font-size: 0.86rem;
}

.result-answer-label {
  color: var(--text-muted);
}

/* Color accents for answers */

.correct-text {
  color: var(--success);
}

.incorrect-text {
  color: var(--danger);
}

/* Responsive */

@media (max-width: 768px) {
  .app-shell {
    padding: 14px 12px 18px;
    border-radius: 20px;
  }

  .app-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .quiz-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .quiz-nav {
    flex-direction: column;
    align-items: stretch;
  }

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

  .card {
    padding: 14px 14px 12px;
  }
}