feat: add theme and style

components/theme/util/getAlphaColor.ts

@@ -0,0 +1,29 @@
+import { TinyColor } from '@ctrl/tinycolor'
+
+function isStableColor(color: number): boolean {
+  return color >= 0 && color <= 255
+}
+
+function getAlphaColor(frontColor: string, backgroundColor: string): string {
+  const { r: fR, g: fG, b: fB, a: originAlpha } = new TinyColor(frontColor).toRgb()
+  if (originAlpha < 1) {
+    return frontColor
+  }
+
+  const { r: bR, g: bG, b: bB } = new TinyColor(backgroundColor).toRgb()
+
+  for (let fA = 0.01; fA <= 1; fA += 0.01) {
+    const r = Math.round((fR - bR * (1 - fA)) / fA)
+    const g = Math.round((fG - bG * (1 - fA)) / fA)
+    const b = Math.round((fB - bB * (1 - fA)) / fA)
+    if (isStableColor(r) && isStableColor(g) && isStableColor(b)) {
+      return new TinyColor({ r, g, b, a: Math.round(fA * 100) / 100 }).toRgbString()
+    }
+  }
+
+  // fallback
+  /* istanbul ignore next */
+  return new TinyColor({ r: fR, g: fG, b: fB, a: 1 }).toRgbString()
+}
+
+export default getAlphaColor