set opacity of text layer to always be 1

Fixes the selection color being too light.

Author: octocorvus

viewer/css/text_layer.css

@@ -1,13 +1,12 @@
 :root {
-    --text-layer-opacity: 0.2;
     --text-layer-foreground: transparent;
 }
 
 .textLayer {
     text-align: initial;
     position: absolute;
     overflow: clip;
-    opacity: var(--text-layer-opacity);
+    opacity: 1;
     line-height: 1;
     text-size-adjust: none;
     forced-color-adjust: none;

viewer/js/index.js

@@ -382,13 +382,10 @@ globalThis.abortDocumentOutline = function () {
 
 globalThis.toggleTextLayerVisibility = function () {
     let textLayerForeground = "red";
-    let textLayerOpacity = 1;
     if (isTextLayerVisible) {
         textLayerForeground = "transparent";
-        textLayerOpacity = 0.2;
     }
     document.documentElement.style.setProperty("--text-layer-foreground", textLayerForeground);
-    document.documentElement.style.setProperty("--text-layer-opacity", textLayerOpacity.toString());
     isTextLayerVisible = !isTextLayerVisible;
 };