:root {
  /* World / grid */
  --world-size: 200;
  --grid-cell-size: 1;
  --brick-height: 0.6;

  /* Scene colours */
  --color-sky: #8fd0f0;
  --color-ground: #5f8a4c;
  --color-grid-line: #ffffff;

  /* Grid targeting highlight */
  --color-highlight-valid: #4caf50;
  --color-highlight-invalid: #e5453e;

  /* Brick palette (index order = hotkeys 1-6) */
  --brick-color-1: #d5352e; /* red */
  --brick-color-2: #f2c230; /* yellow */
  --brick-color-3: #2f6fdd; /* blue */
  --brick-color-4: #3aa655; /* green */
  --brick-color-5: #f2f2f2; /* white */
  --brick-color-6: #2b2b2b; /* black */

  /* HUD chrome */
  --font-hud: system-ui, -apple-system, "Segoe UI", sans-serif;
  --color-hud-bg: rgba(20, 20, 22, 0.72);
  --color-hud-border: rgba(255, 255, 255, 0.18);
  --color-hud-text: #f2f2f2;
  --color-hud-muted: rgba(242, 242, 242, 0.65);
  --color-error-bg: rgba(180, 40, 30, 0.85);
  --spacing-hud: 12px;
  --radius-hud: 8px;
}