Only 1 Div Not 100% in Mobile - html

Question

So I'm working on a quick portfolio and in mobile, the "email me" does not expand across the entire screen as it should, as seen on this screenshot.
I've fiddled around with content width, device width, etc. using numbers, percentages, text values, and nothing has worked to make this page perfect. I rewrote the code to be cleaner and still can't find my mistake. Is it just something I'm overlooking?
You can just view my source to get my code, since the CSS should be there.
UPDATE: I removed the navigation padding and changed all of the device-width values but now the navigation bar does not go completely across. I am very confused since the #navigation and #mobilecontact should essentially have the same widths. I'm using Safari on iPhone.

Answer 1

Can you add the browser and version that you are testing on, because Email me button looks fine for me (occupies entire width) in latest chrome - developer tools.
May be your browser didn't understand 100vw
If you are concerned about the clickable area of "email me" anchor text.
You can make the anchor as display:block, so that it takes up entire row

Answer 2

I think you are using mac safari browser and in safari browser "vw" is not supported so now you can use "px" or "%" and button will be expand.

Answer 3

I have checked.. you need to fix following this
First of all you should remove "width=500" from your meta, highlighted in below image.
Add following in your CSS to fix paddings
* {
box-sizing:border-box;
}
Instead of width: device-width use width: 100% and add more properties in #title . see image
Update CSS for #about, #experience, #skills to width:100%
and thats it you all are done.
Here is final result
All you need to do is to fix font-size

Answer 4

When you want to have a responsive design; you don't need to use specific Width for block level elements.
just
remove numerical width from body's children, then add
body,html
{
width:100%;
box-sizing:border-box;
-webkit-box-sizing:border-box;
-moz-box-sizing:border-box;
}
and then if you want to set padding or margin to viewport element; the standard way is just one element with specific class handle width like bootstrap container class

Answer 5

So I have managed to achieve the required result.
Basically the extra padding you are adding on <div id="navigation"> (padding-left: 350px) is part of the issue.
Also you are incorrectly using the device-width attribute value. One cannot specify the width of html elements using width=device-width;. Width attribute does not accept device-width as an acceptable value.
So replace that with width=100%; or width=100vw; everywhere you have used it. See here for documentation on responsive web design using viewport meta tag and device-width.
I was able to get the button to occupy 100% of the screen width by making these changes.
Remove padding-left: 350px from <div id="navigation">.
For <div id="title"> and <div id="about"> in the media queries for max-width: 500px, changing width from width: device-width to 100% or 100vw.
Here is the output. Let me know if it works out.