Twenty thirteen theme not responsive in mobile- only front page

Hi,

I am Using twenty thirteen theme, but the front page is not covering the entire screen width when I view in mobile ( iphone). I tried modifying my custom.css and the code can be found below:

/* Enter Your Custom CSS Here */

.single-post .site-content {
max-width:100%;
}

@media (max-width: 360px) {
.site {
max-width:100%;
}

.site-content {
max-width:100%;
}

}

@media (min-width: 360px) and (max-width: 767px) {
.site {
max-width:100%;
}
.site-content {
max-width:100%;
}
}

This is the link to my website: https://www.knurld.io/

Please give me some solution, how to make it work properly on mobile devices.