Wordpress title won't change size

[Catherine]

Between the posts and pages on my website, the h1 size won't change:
I've added to the CSS - h1.entry-title {font-size: 100px;}

In the first link (post) it changes, but in the second (a page) it doesn't. It seems to be overridden somewhere and I can't work out where.

Any ideas what's going on?

[Bella]

Add this as custom CSS for.

.ast-single-post .entry-title, .page-title {
font-size: 55px !important;
font-family: sans-serif !important;
font-weight: 700;
}