:root {
  --background: 42 54% 96%;
  --foreground: 222 39% 14%;
  --primary: 173 72% 31%;
  --primary-foreground: 0 0% 100%;
  --secondary: 34 88% 58%;
  --secondary-foreground: 222 39% 14%;
  --muted: 42 30% 89%;
  --muted-foreground: 220 13% 42%;
  --destructive: 0 74% 52%;
  --destructive-foreground: 0 0% 100%;
  --border: 42 25% 82%;
  --card: 0 0% 100%;
  --success: 145 63% 37%;
  --warning: 34 88% 58%;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 12px 30px rgba(15, 23, 42, 0.10);
  --shadow-lg: 0 24px 60px rgba(15, 23, 42, 0.16);
  --transition-fast: 150ms ease;
  --transition-smooth: 280ms cubic-bezier(.2,.8,.2,1);
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
}
.dark {
  --background: 220 31% 8%;
  --foreground: 42 54% 96%;
  --primary: 173 68% 45%;
  --primary-foreground: 222 39% 10%;
  --secondary: 34 88% 62%;
  --secondary-foreground: 222 39% 10%;
  --muted: 220 24% 15%;
  --muted-foreground: 220 14% 74%;
  --destructive: 0 70% 58%;
  --destructive-foreground: 0 0% 100%;
  --border: 220 20% 22%;
  --card: 220 28% 12%;
  --success: 145 59% 48%;
  --warning: 34 88% 62%;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(circle at top left, hsl(var(--primary) / 0.16), transparent 30rem),
    radial-gradient(circle at bottom right, hsl(var(--secondary) / 0.18), transparent 28rem),
    hsl(var(--background));
  color: hsl(var(--foreground));
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
button, input, select { font: inherit; }
button, a, input, select { transition: var(--transition-fast); }
.card { background: hsl(var(--card) / .92); border: 1px solid hsl(var(--border)); border-radius: var(--radius-lg); box-shadow: var(--shadow-sm); }
.card-hover:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }
.focus-ring:focus { outline: 3px solid hsl(var(--primary) / .28); outline-offset: 2px; }
.progress-track { height: 10px; border-radius: 999px; background: hsl(var(--muted)); overflow: hidden; }
.progress-fill { height: 100%; border-radius: 999px; background: linear-gradient(90deg, hsl(var(--primary)), hsl(var(--secondary))); }
.timer-display { font-variant-numeric: tabular-nums; }
@media (max-width: 640px) { .mobile-scroll { overflow-x: auto; -webkit-overflow-scrolling: touch; } }