HTML input textbox with a width of 100% overflows table cells

Question

Does anyone know why the input elements with a width of 100% go over the table\'s cells border.

In the simple example below input box go over the table\'s cells border,

Answer 1

The problem lies in border-width of input element. Shortly, try setting the margin-left of the input element to -2px.

table input {
  margin-left: -2px;
}