I updated the site design a bit, so Iโd like to share the CSS I used.
Implementing Striped Stripes
.site-header
background: #009999;
background-image: -webkit-gradient(linear,0 0,100% 100%, color-stop(.25,#ffffff), color-stop(.25,transparent), color-stop(.5,transparent), color-stop(.5,#ffffff), color-stop(.75,#ffffff), color-stop(.75,transparent),to(transparent));
-webkit-background-size: 1000px;
You can change the color by modifying the color code fff in the above code.
You can adjust the size of the stripes by changing the value of -webkit-background-size: 1000px;.
Making Elements Semi-transparent
.main-body-in
background-color: rgba(255, 255, 255, 0.7);
Also, since the background being too assertive makes it hard to read, I placed a semi-transparent white sheet in the background. You can change the semi-transparency by tweaking the value of 0.7. 1.0 is opaque.