Has CSS Changed for Common Elements?

Has CSS Changed for Common Elements?

I noticed today that the standard title headings on my Forms and Reports display smaller in size than before. 

Google Dev Tools (attached), seems to confirm my suspicion. Something appears to be overriding the 1.375rem to 1.125rem. The font size on the page is 18px. Here's the styling for the view header from new_theme:

.view-header>.row h3 {
    font-size: 1.375rem;
    color: #333;
    font-weight: 300;
    padding-left: 45px;
    line-height: 34px
}

Am I reading this right? If so, any ideas on what's causing it?

Note, I have not implemented any CSS overrides on this report (or the related form). It's straight out of the box. I cleared Chrome and logged out/in, but still the same result.

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