修复暗色主题下find高亮时光标看不清的问题

src/components/FindReplace.vue

@@ -383,6 +383,10 @@ export default {
 .find-replace-highlighting {
   background-color: $highlighting-color;
   color: $editor-color-light !important;
+
+  .app--dark & {
+    background-color: $dark-highlighting-color;
+  }
 }
 
 .find-replace-selection {

src/styles/variables.scss

@@ -8,6 +8,7 @@ $line-height-base: 1.67;
 $line-height-title: 1.33;
 $font-size-monospace: 0.85em;
 $highlighting-color: #ff0;
+$dark-highlighting-color: rgba(255, 255, 0, 0.6);
 $selection-highlighting-color: #ffb067;
 $info-bg: #ffad3326;
 $code-border-radius: 3px;