How can I make a TextArea 100% width without overflowing when padding is present in CSS?

Question

I have the following CSS and HTML snippet being rendered.

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Answer 1

If you're not too bothered about the width of the padding, this solution will actually keep the padding in percentages too..

textarea
{
    border:1px solid #999999;
    width:98%;
    margin:5px 0;
    padding:1%;
}

Not perfect, but you'll get some padding and the width adds up to 100% so its all good