How to add line below every heading of H2 level

Hi there,

try this CSS - not sure if you wanted H2 or H3

.entry-content h2:before {
    content: '';
    width: 100%;
    height: 3px;
    position: absolute;
    top: 100%;
    left: 0;
    background-color: #f5f5f5;
}
.entry-content h2:after {
    content: '';
    width: 10%;
    height: 3px;
    position: absolute;
    top: 100%;
    left: 0;
    background-color: #2f4468;
}

I want to add line after every heading except main heading of blog

its not working

I want line like this

Can you provide me a link to your site.
You can edit your original topic and use the Site URL field to share it privately.