How to make full width sections

Hello,

I am using the optimizer theme to create a website. I have the layout set to “full-width layout.” In addition, I am using Magee Shortcodes to create content sections on pages.

I added the following CSS to increase the width of the sections (which were not full-width, even though I have it set to the full width layout):
*/
.lay4 {
width: 100%;
float: left;
padding: 0;
}

body {
background: #ffffff;
margin: 0;
padding: 0;
font-family: Arial, Helvetica, sans-serif;
font-size: 16px;
color: #000000;
}

.center {
width: 100%;
margin: 0;
}

img {
max-width: 100%;
}

The width of the sections increased, but they are still not full width. There is now a small margin between the backgrounds of the sections and the page background.

Here is the URL for reference:
https://d1f.8dd.myftpupload.com/

In addition, if anyone can recommend some better plugins for testimonials (one that looks really sharp), that would be great!

Thank you!