[jquery] How can I change the width and height of slides on Slick Carousel?

Basically you need to edit the JS and add (in this case, inside $('#featured-articles').slick({ ), this:

variableWidth: true,

This will allow you to edit the width in your CSS where you can, generically use:

.slick-slide {
    width: 100%;
}

or in this case:

.featured {
    width: 100%;
}