🐛 Fixed #140, add selection backgroud make it show clear.

assets/css/_common/scaffolding/base.scss

@@ -1,6 +1,7 @@
 ::selection {
-  background: $selection-bg;
-  color: $selection-color;
+  background: var(--selection-bg);
+  color: var(--selection-color);
+
 }
 
 html, body {

assets/css/_common/scaffolding/highlight/copy-code.scss

@@ -3,6 +3,7 @@
 
   background: var(--highlight-background);
   margin-bottom: 26px;
+  line-height: 1.185;
 
   //TODO  Need fixed the copy button show position.
   div:first-child {
@@ -12,14 +13,16 @@
   pre {
     position: relative;
     overflow-x: auto;
-    padding: 4px;
+    padding: 6px;
+    overflow-wrap: break-word;
+    line-break: anywhere;
   }
 
-  table tbody tr {
+ /* table tbody tr {
     //TODO Fixed the too long code line over
     // layout background color.
     background: #272822;    
-  }
+  }*/
 
   /* pre > code span {
     white-space: break-spaces;