Highlight rules suck. I think these work. This is what happens when an iOS Dev tries his hand at CSS.
diff --git a/themes/prism-solarizedlight b/themes/prism-solarizedlight
index 9aa4bd3..d733f37 100644
--- a/themes/prism-solarizedlight
+++ b/themes/prism-solarizedlight
@@ -119,8 +119,10 @@ pre[class*="language-"] {
cursor: help;
}
-pre>code.highlight {
- outline: 0.4em solid #dc322f;
- outline-offset: .4em
+::selection {
+ background: #CAD6D9;
+}
+::-moz-selection {
+ background: #CAD6D9;
}