main.less

@font-size: 1.2em;
@color: #aaa;

.CodeMirror-foldgutter {
	&-open:after {
    	content: "\25bc";
		font-size: @font-size;
		color: @color;
	}
	&-folded:after {
    	content: "\25b6";
		font-size: @font-size;
		color: @color;
	}
}

.CodeMirror-foldgutter,
.CodeMirror-foldgutter-open,
.CodeMirror-foldgutter-folded,
.CodeMirror-foldgutter-blank {
    width: @font-size;
    cursor: default;
    line-height: 100%;
}

.CodeMirror-foldmarker {
    padding-right: 5px;
    padding-left: 5px;
    margin-right: 3px;
    margin-left: 3px;
    border-radius: 3px;
    cursor: pointer;
	border: 1px solid lighten(@color, 10%);
	color: darken(@color, 20%);
	background-color: lighten(@color, 20%);
}

#code-folding-settings-dialog {
	label {
		width: 40%;
		padding-right: 10px;
	}
	input[type=number] {
		width: 40px;	
	}
}