/* ============ Reset & Variables ============ */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --primary: #0d9488;
  --primary-light: #14b8a6;
  --primary-dark: #0f766e;
  --primary-bg: #f0fdfa;
  --bg: #faf9f7;
  --bg-white: #ffffff;
  --bg-secondary: #f5f5f4;
  --bg-sidebar: #f5f3f0;
  --text: #1c1917;
  --text-secondary: #78716c;
  --text-muted: #a8a29e;
  --border: #e7e5e4;
  --border-light: #f0eeec;
  --error: #ef4444;
  --code-bg: #1c1917;
  --shadow: 0 1px 3px rgba(0,0,0,0.04), 0 1px 2px rgba(0,0,0,0.03);
  --shadow-lg: 0 4px 16px rgba(0,0,0,0.06);
  --radius: 12px;
  --radius-sm: 8px;
  --sidebar-width: 280px;
  --font-sans: 'Outfit', -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  --font-serif: 'Fraunces', 'Georgia', serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', 'Fira Code', 'Menlo', monospace;
}

html, body {
  height: 100%;
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
}

/* ============ Shared Animations ============ */
@keyframes cardFadeIn {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ============ Shared Components ============ */
.logout-btn {
  width: 100%;
  padding: 8px;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-family: var(--font-sans);
  font-size: 13px;
  cursor: pointer;
  transition: all 0.2s;
}

.logout-btn:hover {
  border-color: var(--error);
  color: var(--error);
}

.quiz-btn {
  padding: 10px 24px;
  border-radius: var(--radius-sm);
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  border: none;
}

.quiz-btn-primary {
  background: var(--primary);
  color: #fff;
}

.quiz-btn-primary:hover {
  background: var(--primary-dark);
}

.quiz-btn-primary:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.quiz-btn-secondary {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border);
}

.quiz-btn-secondary:hover {
  border-color: var(--primary-light);
  color: var(--primary);
}

/* ============ Scrollbar ============ */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: #d6d3d1;
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: #a8a29e;
}