CSS does not fit

Issue

I am building a page example on this fiddle

The scrollbar (horizontal) appears :

I want this page to be fit on the browser, to there should not a scrollbar. please help _/_

Solution

The reason is because of this section:

#content{
    position: relative;
    width: calc(100%-260px);
    left: 260px;
}

You can change the left to margin-left which will solve your issue, like below (you can also get rid of the width: calc(100%-260px); then):

#content{
    position: relative;
    margin-left: 260px;
}

Answered By - Corné