Have block level element fill 100% width of overflow-x: scroll container

Question

I\'ve got a container element that\'s a certain width, with overflow-x: auto. In it I have a block level header element (h1) that\'s supposed to, being a block

Answer 1

Change this CSS code like the following then check and let me know if you want this:

#one {
width: 100%;
overflow: auto;
border: solid 1px;
}