Numbered classes in attribute selectors are ignored - Mailchimp

[ivandurst]

Today I noticed a mailchimp issue that caused some of your classes to be ignored. When you use attribute selectors in Mailchimp, such as

*[class="100p"] {
  width: 100% !important;
  height: auto !important;
}

Mailchimp strips out the quotes, so you're left with *[class=100p]. Attribute selectors that begin with numbers and aren't quoted are invalid, and are ignored. Just a heads up, as I've also seen these class names in a Litmus article about "how to build an email from scratch," and this will baffle any newer developers working with Mailchimp.