Css Heading h3 in child theme

Hi,

I can’t seem to get hold of the h3 style for my page.

Whatever I change, the style isn’t implemented.

What I have tried so far :

.entry h3 {
font-size: 24.5px !important;
color:red !important;
}

h3 {
font-size: 24.5px !important;
color:red !important;
}

I tried to give the h3 a class like this in my wp-page (edited in textmode) <h3 class=”blah”>headline</h3> and then style this class in my childthemes css file. Didn’t work.

I tried everything suggested here http://codex.wordpress.org/Designing_Headings.
Nothing.

I can’t get this to work. Where to style a simple h3 heading in my wordpress page? Appreciate any help.