:root {
  --background: 0 0% 98%;
  --foreground: 0 0% 4%;
  --primary: 0 0% 4%;
  --secondary: 0 0% 92%;
  --muted: 0 0% 38%;
  --destructive: 0 72% 44%;
  --border: 0 0% 84%;
  --card: 0 0% 100%;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.06);
  --shadow-md: 0 14px 35px rgba(0,0,0,0.08);
  --shadow-lg: 0 24px 80px rgba(0,0,0,0.16);
  --transition-fast: 160ms ease;
  --transition-smooth: 320ms cubic-bezier(.2,.8,.2,1);
  --radius-sm: 0.75rem;
  --radius-md: 1rem;
  --radius-lg: 1.5rem;
}

.dark {
  --background: 0 0% 4%;
  --foreground: 0 0% 98%;
  --primary: 0 0% 98%;
  --secondary: 0 0% 12%;
  --muted: 0 0% 68%;
  --destructive: 0 72% 54%;
  --border: 0 0% 20%;
  --card: 0 0% 7%;
}

html {
  scroll-behavior: smooth;
  background: hsl(var(--background));
}

body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: hsl(var(--background));
  color: hsl(var(--foreground));
}

button, a {
  transition: transform var(--transition-fast), background-color var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast), opacity var(--transition-fast);
}

button:focus-visible, a:focus-visible {
  outline: 3px solid hsl(var(--foreground));
  outline-offset: 3px;
}

button:active {
  transform: scale(0.98);
}

input, textarea, select {
  font-size: max(16px, 1rem);
}

section {
  scroll-margin-top: 96px;
}

.grid-bg {
  background-image: linear-gradient(hsl(var(--border)) 1px, transparent 1px), linear-gradient(90deg, hsl(var(--border)) 1px, transparent 1px);
  background-size: 42px 42px;
  mask-image: radial-gradient(circle at top left, black, transparent 72%);
}

::selection {
  background: hsl(var(--foreground));
  color: hsl(var(--background));
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: 1ms !important; animation-duration: 1ms !important; }
}