Question

I’ve been trying to add a header to my website, but I cannot get the container to fit the full width of the screen, despite the width being set to 100% or auto. It always has about a ~5px margin on both the left and right, even with margin and padding both set to 0.

HTML:

<div id="header">
    <h7>
        <p>Lorem Ipsum</p>
        <p>Lorem Ipsum</p>
        <p>Lorem Ipsum</p>
        <p>Lorem Ipsum</p>
    </h7>
</div>

CSS:

body div#header{
    width: 100%;
    margin: 0;
    padding: 0;
    background-color: #c0c0c0;
}

Answer 1

Add

body, html{
  margin:0;
  padding:0;
}

to your CSS.

Browsers put default margins and/or paddings when rendering websites. With this you can avoid that.