style.css

.CodeMirror {
  border: 1px solid #eee;
}

.CodeMirror-lint-mark-style {
  background-position: left bottom;
  background-repeat: repeat-x;
}

.CodeMirror-lint-mark-style {
  background-image: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAQAAAADCAYAAAC09K7GAAAABmJLR0QA/wD/AP+gvaeTAAAACXBIWXMAAAsTAAALEwEAmpwYAAAAB3RJTUUH4AcfER8yeKO8ogAAAB1pVFh0Q29tbWVudAAAAAAAQ3JlYXRlZCB3aXRoIEdJTVBkLmUHAAAANklEQVQI12NkgAK9DV8WMjAwdDPqbfgSysDA4MPAwNDNwMCwiImBgaGSgYGh+1IAzxUGBoYUAPEkCg3hrXiCAAAAAElFTkSuQmCC');
}

.CodeMirror-lint-marker-style {
  background-position: center center;
  background-repeat: no-repeat;
  cursor: pointer;
  display: inline-block;
  height: 16px;
  width: 16px;
  vertical-align: middle;
  position: relative;
}

.CodeMirror-lint-message-style {
  padding-left: 18px;
  background-position: top left;
  background-repeat: no-repeat;
}

.CodeMirror-lint-marker-style, .CodeMirror-lint-message-style {
  background-image: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAABmJLR0QA/wD/AP+gvaeTAAAACXBIWXMAAAsTAAALEwEAmpwYAAAAB3RJTUUH4AcfER8kjHcJ8wAAANhJREFUOMvNkz0OgkAUhN+AMSFACDYWXkDvsvESttbEDlvus3fRK9hIiBASQMdCC9Dlp2Sbzb7MvHxvdldk1guaB2gSmodezYDZYZHd4AY+i+wBN1hTofzVWQMAR7iBLyLy3Y+TCaAZMk/v8EKhgkBTmKcCL1xRIZ1CEMELu00/52h0BGhuWJUnU1dW5QmamzGCGEvHHOynHvdmAM0tX88LLLs3Wb6eAsveUeH6R8CmTn7NVN2cYdnCpk7MI9iL/aQX1tJ1GgAwXel/raWDwXAeA6DCeT4f7g3oo0iKtxG/4QAAAABJRU5ErkJggg==')
}

.cm-s3c-delimiter {
  background-color: #fec;
}

.cm-comment + .cm-s3c-delimiter {
  color: #a50;
  background-color: inherit;
}

.s3c-runtime-error {
  background-color: #fbb;
}

.cm-comment + .cm-s3c-delimiter + .s3c-runtime-error {
  color: #a50;
  background-color: inherit;
}

#button-run {
  background-color: #2ecc71;
  color: white;
  text-shadow: 0 1px 0 rgba(0,0,0,0.15);
  font-size: 140%;
  border: 1px solid #27ae60;
  border-radius: 4px;
  padding: 0.25em 0.5em;
  cursor: pointer;
}

#button-run:hover {
  background-color: #27ae60;
}

#button-run.in-progress {
  background-color: #f39c12;
  border: 1px solid #f39c12;
}

#button-run.parse-error {
  background-color: #c0392b;
  border: 1px solid #c0392b;
  cursor: default;
}

label[for="timeout"] {
  margin-left: 2em;
}