Page Title Font Size

How do I increase the size of the PAGE TITLE font?

Here is the current code

.page-header-title {
    display: block;
    font-size: 24px;
    line-height: 1.4em;
    font-weight: 400;
    margin: 0;
    color: #333;
}

The code above is blocking the H1 style.

Am I missing something? I thought we could change the font size through the customizer.

The page I need help with: [log in to see the link]