:root {
  --background: 210 38% 97%;
  --foreground: 222 47% 11%;
  --primary: 212 92% 45%;
  --primary-foreground: 0 0% 100%;
  --secondary: 174 72% 41%;
  --secondary-foreground: 0 0% 100%;
  --muted: 215 22% 90%;
  --muted-foreground: 215 18% 38%;
  --destructive: 0 78% 55%;
  --destructive-foreground: 0 0% 100%;
  --border: 214 24% 84%;
  --card: 0 0% 100%;
  --shadow-sm: 0 2px 10px hsl(222 47% 11% / 0.06);
  --shadow-md: 0 12px 30px hsl(222 47% 11% / 0.10);
  --shadow-lg: 0 24px 60px hsl(222 47% 11% / 0.16);
  --transition-fast: 140ms ease;
  --transition-smooth: 260ms cubic-bezier(.2,.8,.2,1);
  --radius-sm: 0.6rem;
  --radius-md: 1rem;
  --radius-lg: 1.5rem;
}
.dark {
  --background: 222 47% 8%;
  --foreground: 210 40% 96%;
  --primary: 205 95% 62%;
  --primary-foreground: 222 47% 8%;
  --secondary: 174 70% 48%;
  --secondary-foreground: 222 47% 8%;
  --muted: 222 28% 17%;
  --muted-foreground: 215 20% 72%;
  --destructive: 0 82% 64%;
  --destructive-foreground: 222 47% 8%;
  --border: 222 24% 23%;
  --card: 222 36% 12%;
}
* { 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 34rem),
    radial-gradient(circle at top right, hsl(var(--secondary) / 0.14), 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, a, input, select, textarea { transition: var(--transition-smooth); }
input, select, textarea { font-size: max(16px, 1rem); }
button, .tap-target { min-height: 44px; min-width: 44px; }
.card { background: hsl(var(--card) / 0.88); border: 1px solid hsl(var(--border)); box-shadow: var(--shadow-sm); border-radius: var(--radius-lg); backdrop-filter: blur(16px); }
.mermaid-box svg { max-width: 100%; height: auto; }
.safe-bottom { padding-bottom: calc(5.5rem + env(safe-area-inset-bottom)); }
.focus-ring:focus { outline: 3px solid hsl(var(--primary) / 0.28); outline-offset: 2px; }