findCSS supports most of the CSS3 recommendation(plus a few extras). Here is a complete list of all CSS syntax supported.

• *
• div
• div,span,p
• #id
• div#id
• div.classname
• div span
• div > span
• div + div
• div ~ div
• div[id]
• div[id="id"]
• div[id*="id"]
• div[id^="id"]
• div[id$="id"]
• div[class~="classname"]
• a[hreflang|="en"]
• div:first-child
• div:last-child
• div:only-child
• div:empty
• div:nth-child(1)
• div:even or div:nth-child(even)
• div:odd or div:nth-child(odd)
• div:not(div:even)
• div:contains("Some Text")
• div:target
• input:checked
• input:disabled
• input[type="checkbox"]#id.classname:checked:not(input:disabled):even