Eight-digit hex color is ignored by an older embedded browser

• The layer is entirely absent in the embedded Chromium 76 while no console error is printed
• The DOM keeps the literal `fill="#1a6fd4cc"` on the SVG path
• `CSS.supports('color', '#1a6fd4cc')` returns `false` in that client

1. Read the `fill` attribute string on the path in the Elements panel
2. Paste the value into a CSS `background-color` to see whether the engine parses it
3. Run `CSS.supports('color', '#1a6fd4cc')` inside the target browser
4. Compare rendering across new and old engines to rule out a data problem
5. Check whether the alpha was meant for `fillOpacity` in the first place

Keep the color six digits and set opacity separately (`fillColor: '#1a6fd4', fillOpacity: 0.8`); if eight-digit values already exist, split them at runtime with `hex.slice(0, 7)` and `parseInt(hex.slice(7), 16) / 255`.

console.log(CSS.supports('color', '#1a6fd4cc'));   // false  -> 该内核不支持八位色值
console.log(document.querySelector('path').getAttribute('fill'));   // #1a6fd4cc

L.geoJSON(data, {
  style: {
    fillColor: '#1a6fd4',
    fillOpacity: 0.8,
    color: '#1259ad',
    opacity: 0.9,
    weight: 1
  }
}).addTo(map);

• Assuming a color string valid in modern Chrome parses everywhere; SVG 1.1 `fill` rejects eight-digit hex
• Putting `rgba()` into the `fillColor` option, which Leaflet writes into an SVG attribute rather than CSS