Fix styling issues in the sidebar

_static/css/custom.css

@@ -1030,6 +1030,7 @@ kbd.compound > .kbd,
 .wy-menu-vertical li a button.toctree-expand {
     position: relative;
     width: 12px;
+    min-width: 12px; /* Forces the size to stay this way in the flexbox model. */
     height: 18px;
 }
 

_static/js/custom.js

@@ -324,3 +324,8 @@ $(document).ready(() => {
     registerOnScrollEvent(mediaQuery);
   }
 });
+
+// Override the default implementation from doctools.js to avoid this behavior.
+Documentation.highlightSearchWords = function() {
+  // Nope.
+}