IPython/frontend/html/notebook/static/codemirror/lib/codemirror.css

.CodeMirror {
  line-height: 1em;
  font-family: monospace;
}

.CodeMirror-scroll {
  overflow: auto;
  height: 300px;
  /* This is needed to prevent an IE[67] bug where the scrolled content
     is visible outside of the scrolling box. */
  position: relative;
}

.CodeMirror-gutter {
  position: absolute; left: 0; top: 0;
  z-index: 10;
  background-color: #f7f7f7;
  border-right: 1px solid #eee;
  min-width: 2em;
  height: 100%;
}
.CodeMirror-gutter-text {
  color: #aaa;
  text-align: right;
  padding: .4em .2em .4em .4em;
  white-space: pre !important;
}
.CodeMirror-lines {
  padding: .4em;
}

.CodeMirror pre {
  -moz-border-radius: 0;
  -webkit-border-radius: 0;
  -o-border-radius: 0;
  border-radius: 0;
  border-width: 0; margin: 0; padding: 0; background: transparent;
  font-family: inherit;
  font-size: inherit;
  padding: 0; margin: 0;
  white-space: pre;
  word-wrap: normal;
}

.CodeMirror-wrap pre {
  word-wrap: break-word;
  white-space: pre-wrap;
}
.CodeMirror-wrap .CodeMirror-scroll {
  overflow-x: hidden;
}

.CodeMirror textarea {
  outline: none !important;
}

.CodeMirror pre.CodeMirror-cursor {
  z-index: 10;
  position: absolute;
  visibility: hidden;
  border-left: 1px solid black;
}
.CodeMirror-focused pre.CodeMirror-cursor {
  visibility: visible;
}

div.CodeMirror-selected { background: #d9d9d9; }
.CodeMirror-focused div.CodeMirror-selected { background: #d7d4f0; }

.CodeMirror-searching {
  background: #ffa;
  background: rgba(255, 255, 0, .4);
}

/* Default theme */

.cm-s-default span.cm-keyword {color: #708;}
.cm-s-default span.cm-atom {color: #219;}
.cm-s-default span.cm-number {color: #164;}
.cm-s-default span.cm-def {color: #00f;}
.cm-s-default span.cm-variable {color: black;}
.cm-s-default span.cm-variable-2 {color: #05a;}
.cm-s-default span.cm-variable-3 {color: #085;}
.cm-s-default span.cm-property {color: black;}
.cm-s-default span.cm-operator {color: black;}
.cm-s-default span.cm-comment {color: #a50;}
.cm-s-default span.cm-string {color: #a11;}
.cm-s-default span.cm-string-2 {color: #f50;}
.cm-s-default span.cm-meta {color: #555;}
.cm-s-default span.cm-error {color: #f00;}
.cm-s-default span.cm-qualifier {color: #555;}
.cm-s-default span.cm-builtin {color: #30a;}
.cm-s-default span.cm-bracket {color: #cc7;}
.cm-s-default span.cm-tag {color: #170;}
.cm-s-default span.cm-attribute {color: #00c;}
.cm-s-default span.cm-header {color: #a0a;}
.cm-s-default span.cm-quote {color: #090;}
.cm-s-default span.cm-hr {color: #999;}
.cm-s-default span.cm-link {color: #00c;}

span.cm-header, span.cm-strong {font-weight: bold;}
span.cm-em {font-style: italic;}
span.cm-emstrong {font-style: italic; font-weight: bold;}
span.cm-link {text-decoration: underline;}

div.CodeMirror span.CodeMirror-matchingbracket {color: #0f0;}
div.CodeMirror span.CodeMirror-nonmatchingbracket {color: #f22;}