Problem: Currently there is no way to manually add to the <head> of an email.
This means:
1) It is impossible to add dark mode support (we have to rely on auto inversion)
2) We can't add our own non-inline styles as gmail ignores style blocks which are outside the head. This means that even though the default 'html' block which is added contains "<div class="our-class"> I'm a new HTML block. </div>" - it is incapable of being targeted at '.our-class'.
Solution:
Provide the ability to add elements to the <head> of the email. This would mean:
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1) We could add dark mode support via:
@media (prefers-color-scheme: dark) {.styles-here…} CSS to control how the email looks in dark mode instead of relying on auto-inversion.
<meta name="color-scheme" content="light dark"> and <meta name="supported-color-schemes"> to signal dark mode support.
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2) We could style our own html blocks by using classes instead of styling each one with inline styles.