body, button, input, select, textarea {
    font-family: 'Karla',sans-serif;
    font-weight: 700;
    font-size: 1rem;
    text-transform: capitalize;
}

Which will capitalize the first letter of all of the words within the body. Change it to inherit or none or something else.

You can find this using your ‘inspector’ in your Chrome browser if you have it.

body, button, input, select, textarea {
    font-family: 'Karla',sans-serif;
    font-weight: 700;
    font-size: 15px;
    font-size: 1rem;
    text-transform: capitalize;
}

Or just add this code to your additional CSS

body, button, input, select, textarea {
    font-family: 'Karla',sans-serif;
    font-weight: 700;
    font-size: 15px;
    font-size: 1rem;
    /* text-transform: capitalize; */
}

Keep in mind that further along in the code most of the above is overwritten by the next cascade of CSS statements.

You can actually use the CSS inspector mentioned above to toggle that on or off and even tweak it further if you wish though on text-transform your choices are limited to uppercase, lowercase and capitalize. Bear in mind that this is only during inspector sessions but you can cut that code when you’re finished and paste it to your working CSS file.