Awesome CSS icons
Note: it is not possible to use :before or :after pseudo content on <input> elements, however if you instead use <button>Label</button>, it will work as desired.
Below is a Font Awesome cheat sheet of all the content values for each icon:
fa-glass "\f000"
fa-music "\f001"
fa-search "\f002"
fa-envelope-o "\f003"
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