I have the following CSS and HTML snippet being rendered.
The answer to many CSS formatting problems seems to be "add another <div>!"
So, in that spirit, have you tried adding a wrapper div to which the border/padding are applied and then putting the 100% width textarea inside of that? Something like (untested):
textarea
{
width:100%;
}
.textwrapper
{
border:1px solid #999999;
margin:5px 0;
padding:3px;
}
<div style="display: block;" id="rulesformitem" class="formitem">
<label for="rules" id="ruleslabel">Rules:</label>
<div class="textwrapper"><textarea cols="2" rows="10" id="rules"/></div>
</div>
How about negative margins?
textarea {
border:1px solid #999999;
width:100%;
margin:5px -4px; /* 4px = border+padding on one side */
padding:3px;
}
Use box sizing property:
-moz-box-sizing:border-box;
-webkit-box-sizing:border-box;
box-sizing:border-box;
That will help
I was looking for an inline-styling solution instead of CSS solution, and this is the best I can go for a responsive textarea:
<div style="width: 100%; max-width: 500px;">
<textarea style="width: 100%;"></textarea>
</div>
For people who use Bootstrap, textarea.form-control can lead to textarea sizing issues as well. Chrome and Firefox appear to use different heights with the following Bootstrap CSS:
textarea.form-conrtol{
height:auto;
}
Why not forget the hacks and just do it with CSS?
One I use frequently:
.boxsizingBorder {
-webkit-box-sizing: border-box;
-moz-box-sizing: border-box;
box-sizing: border-box;
}
See browser support here.