Take a look at this;
Why is the 100% width tab exceeding the container? The content in the container also has a 100% width and this works just fine?
Take a look at this;
Why is the 100% width tab exceeding the container? The content in the container also has a 100% width and this works just fine?
Because the width of the content area is 100%, then you have to add margin, border, padding...
Try:
box-sizing: border-box; width: 100%;
That's because of the padding 10px.
.dc-slick .slick-tab, .dc-slick .slick-tab-image { padding: 10px }
Those extra 20px ( 10px from left and right ) is causing the overflow. If you have firebug installed or a tool like that, such things can be easily figured out.