Left input takes all available space - css

Question

I know this questions has already been answered before and I've read the topics :
Make div take all space left after another div
Expand div to take remaining width
Expand div to max width when floatleft is set
The magic of overflow hidden (external)
However I can't manage to implement them in my case or they simply don't seem to work as I try to have a fix width on the right and a flexible width on the left (unlike the above examples).
Here is my problem (which is fairly simple) : I have a form with a search field (left) and a span element (right). The span element has a fixed width and height. I want the input to fit the remaining left space.
form :
<div id="container">
<form>
<input type="search" />
<span class="submit"></span>
</form>
</div>
style.css :
#container {
width: 300px;
}
[type="search"] {
/* Positionning
* ------------ */
display: block;
height: 40px;
padding: 0px 10px;
vertical-align: top;
}
.submit {
/* Positionning
* ------------ */
display: block;
height: 40px;
width: 50px;
/* Styling
* ------- */
background-color: #CF0526;
}
From what I've read, I thought that a width: 100%; overflow: hidden on the input and a float: right on the span who be enough, sadly not. Here is a jsfiddle of my problem, hopefully it may help you.
EDIT: I changed the title from "left div" to "left input" as it may matter, especially since this solution does not work while it looks accurate for divs positionning.

Answer 1

You can try with the property calc like this:
input[type="search"] {
width: calc(100% - 40px);
margin:0;
padding:0;
height:30px;
float:left;
}
.submit {
float:left;
width: 40px;
height: 30px;
background-color: red;
}
The demo http://jsfiddle.net/SL3FB/10/ ... Maybe a problem the compatibility
Another solution using box.sizing who has more compatibility: http://jsfiddle.net/SL3FB/18/

Answer 2

You can substract the width from the span to the width from the textfield which is 100%.
Here is the fiddle http://jsfiddle.net/SL3FB/15/.
Code is like this:
width:calc(100% - 50px);
float:left;
Make 'em both float:left; to have a better result!
Hope this works for you.

Answer 3

Use CSS Tables
1) Set display: table-cell for both the input and the span
2) Set a fixed width on the span and (the trick:) width:100% on the input
FIDDLE
#container {
width: 300px;
border: 1px solid black;
}
form
{
display:table;
width: 100%;
}
.submit {
display:table-cell;
width: 40px;
height: 30px;
background-color: red;
}
input
{
width: 100%;
display:table-cell;
}

Answer 4

Does this work for you?
http://jsfiddle.net/SL3FB/4/
I've given your search a width of 85% so it fits up agains the red box.
.search {
width:85%;
}