@tailwind base;
@tailwind components;
@tailwind utilities;

@layer base {
  :root {
    /* Monochrome chrome: the shell carries no color of its own, so the
       five algorithm-state colors below are the only color on the page. */
    --background: 224 15% 6%;
    --foreground: 210 20% 95%;

    --primary: 210 25% 96%;          /* near-white, inverted CTA fill */
    --primary-foreground: 224 20% 9%;
    --secondary: 224 12% 15%;
    --secondary-foreground: 210 15% 90%;
    --accent: 224 12% 17%;           /* neutral hover surface, not a brand color */
    --accent-foreground: 210 20% 95%;
    --destructive: 358 65% 55%;
    --destructive-foreground: 210 20% 96%;
    --muted: 224 12% 13%;
    --muted-foreground: 216 10% 62%;
    --card: 224 14% 9%;
    --card-foreground: 210 20% 95%;
    --popover: 224 16% 8%;
    --popover-foreground: 210 20% 95%;
    --border: 224 12% 18%;
    --input: 224 12% 18%;
    --ring: 205 90% 62%;             /* the one deliberate accent: focus only */
    --radius: 0.75rem;

    /* Algorithm state colors — one meaning each, used everywhere. */
    --state-idle: 205 40% 50%;
    --state-compare: 43 90% 60%;
    --state-swap: 358 75% 59%;
    --state-sorted: 152 55% 48%;
    --state-pivot: 271 70% 66%;
    --state-active-range: 205 60% 55%;
  }
}

@layer base {
  * {
    @apply border-border;
  }

  body {
    @apply bg-background text-foreground;
    background-image:
      linear-gradient(hsl(var(--border) / 0.35) 1px, transparent 1px),
      linear-gradient(90deg, hsl(var(--border) / 0.35) 1px, transparent 1px);
    background-size: 44px 44px;
    background-position: center -1px;
  }

  ::selection {
    background: hsl(var(--accent) / 0.35);
  }

  ::-webkit-scrollbar {
    width: 10px;
    height: 10px;
  }
  ::-webkit-scrollbar-track {
    background: transparent;
  }
  ::-webkit-scrollbar-thumb {
    background: hsl(var(--border));
    border-radius: 999px;
  }
}

@layer utilities {
  .text-balance {
    text-wrap: balance;
  }
  .bg-grid-fade {
    -webkit-mask-image: radial-gradient(ellipse at center, black 40%, transparent 85%);
    mask-image: radial-gradient(ellipse at center, black 40%, transparent 85%);
  }
}