instant match hl same as other editors

also enable it when the find dialog is open because selection may be different

edit/codemirror-default.css

@@ -75,6 +75,10 @@
 .CodeMirror-linenumber {
   cursor: pointer; /* for bookmarking */
 }
+.cm-matchhighlight,
+.CodeMirror-selection-highlight-scrollbar {
+  background: hsla(200, 100%, 50%, var(--match-hl-opacity, .1));
+}
 
 /* Custom stuff we add to CodeMirror */
 
@@ -86,6 +90,9 @@
 }
 
 @media screen and (prefers-color-scheme: dark), dark {
+  .CodeMirror {
+    --match-hl-opacity: .18;
+  }
   .CodeMirror-dialog {
     background-color: #333;
   }

edit/codemirror-factory.js

@@ -83,6 +83,7 @@
       const opt = (showToken || value === 'selection') && {
         showToken,
         annotateScrollbar: true,
+        delay: 0,
         onUpdate: updateMatchHighlightCount,
       };
       cm.setOption('highlightSelectionMatches', opt || null);

edit/edit.css

@@ -510,15 +510,6 @@ label {
 .resize-grip-enabled .CodeMirror-scrollbar-filler {
   bottom: 7px; /* make space for resize-grip */
 }
-body:not(.find-open) .cm-matchhighlight,
-body:not(.find-open) .CodeMirror-selection-highlight-scrollbar {
-  animation: fadein-match-highlighter 1s cubic-bezier(.97,.01,.42,.98);
-  animation-fill-mode: both;
-}
-body:not(.find-open) [data-match-highlight-count="1"] .cm-matchhighlight,
-body:not(.find-open) [data-match-highlight-count="1"] .CodeMirror-selection-highlight-scrollbar {
-  animation: none;
-}
 @keyframes highlight {
   from {
     background-color: #ff9;
@@ -535,10 +526,6 @@ body:not(.find-open) [data-match-highlight-count="1"] .CodeMirror-selection-high
     opacity: 1;
   }
 }
-@keyframes fadein-match-highlighter {
-  from { background-color: transparent; }
-  to   { background-color: rgba(1, 151, 193, 0.1); }
-}
 .resize-grip {
   position: absolute;
   display: block;