[Resolved] Chage font size in AMP homepage and categories

Hello!

You so kindly make this CSS to make my AMP hompage and categories lool like this:

https://monosnap.com/file/GBSXhI8lROJcpMLaGIuF9eMZoWwhNa

Here the CSS:

@media (max-width: 768px) {
.post-image {
float: left;
margin-right: 1.5em;
}

.post-image img {
max-width: 100px;
}

.entry-summary {
display: none;
}
}

How can i change the font size only in this CSS, i mean without changing H2 in the post? And how do I add a little excerpt?

Is not urgent.

Thank you in advanced