/* css/bottom-type.css — P4-04. Seafloor bottom-type fills (reef/sand/pavement).
   Owned by P4-04.

   RULES (same contract as css/coverage.css):

   1. EVERY VISUAL VALUE IS A CUSTOM PROPERTY. The polygons render through a
      Leaflet canvas renderer, so js/bottom-type.js reads these --btype-*
      properties ONCE at init with getComputedStyle (they also seed the
      CLASS_COLORS export the legend uses). Change a colour here, not in JS.

   2. NOTHING GLOBAL. Only --btype-* custom properties on :root.

   COLOURS: three-way palette chosen to survive deutan/protan/tritan vision
   over a dark ocean basemap: the trio differs in LIGHTNESS as much as hue
   (light warm sand, saturated dark orange reef, light cool purple pavement).
   reef/pavement = structure, sand = not — the two structure classes sit at
   the saturated ends, sand is the pale one.

   LOADING: js/bottom-type.js injects a <link> to this file at module load,
   guarded by element id. The integrator can replace that with a static
   <link> in index.html (and add this file to the service-worker precache). */

:root {
  --btype-reef:     #e66101;   /* dark vivid orange — coral/aggregate reef  */
  --btype-sand:     #ffd97d;   /* pale warm sand                            */
  --btype-pavement: #b19ce0;   /* light cool purple — consolidated hardflat */

  --btype-fill-opacity:   0.42;
  --btype-stroke-opacity: 0.8;
  --btype-stroke-weight:  0.75;  /* px — hairline seam between habitat cells */
}