style: update styles.

Author: jaywcjlove

src/codemirror.css

@@ -33,7 +33,6 @@
   background-color: #f7f7f7;
   white-space: nowrap;
 }
-.CodeMirror-linenumbers {}
 .CodeMirror-linenumber {
   padding: 0 3px 0 5px;
   min-width: 20px;
@@ -94,9 +93,6 @@
   100% {}
 }
 
-/* Can style cursor different in overwrite (non-insert) mode */
-.CodeMirror-overwrite .CodeMirror-cursor {}
-
 .cm-tab { display: inline-block; text-decoration: inherit; }
 
 .CodeMirror-rulers {
@@ -125,10 +121,6 @@
 .cm-s-default .cm-atom {color: #219;}
 .cm-s-default .cm-number {color: #164;}
 .cm-s-default .cm-def {color: #00f;}
-.cm-s-default .cm-variable,
-.cm-s-default .cm-punctuation,
-.cm-s-default .cm-property,
-.cm-s-default .cm-operator {}
 .cm-s-default .cm-variable-2 {color: #05a;}
 .cm-s-default .cm-variable-3, .cm-s-default .cm-type {color: #085;}
 .cm-s-default .cm-comment {color: #a50;}