satchlj.com/themes/zenn/sass/_icons.scss

#glyphicons-halflings {
    display: inline-block;
    max-width: 1.2em;
    max-height: 1.2em;
    margin-bottom: -5px;
    fill: $color-text;
}

#{headings(1,6)} {
    #glyphicons-halflings {
        fill: $color-header;
    }
}

.muted #glyphicons-halflings {
    fill: $color-text-muted;
}