Make the menu button disappear, etc..

hi again, I painted white the menu button and words and that is ok now, but I can’t paint the line under the title… can you tell me where to change that? Also the posts are justified left and I need them to be centered like the title: https://www.martinezramos.com/?p=25
thank you,
ana

You can add this custom CSS.

.entry-title::before, .widget-title::before { background-color: #fff; }