Normalize vertical centering of form items across browsers.

input-height.less

/**
 * This will normalize vertical centering of input text across browsers.
 */
.mixin-input-height (@font-size, @height-scale: 2.5) {
	@input-height: @font-size * @height-scale;
	@input-padding-vertical: (@input-height - @font-size) / 2;

	font-size: @font-size;
	height: @input-height + 2; // webkit seems to have a weird 1px gap
	// to vertically center input text in IE <= 8, but not stretch caret in modern browsers
	// @see http://www.paulirish.com/2009/browser-specific-css-hacks/
	line-height: e(%("%d\9", @input-height));
}

/**
 * This will normalize vertical centering of form items (inputs, buttons, etc.) across browsers.
 */
.mixin-form-items-height (@font-size, @height-scale: 2.5) {
	@input-height: @font-size * @height-scale;
	@input-padding-vertical: (@input-height - @font-size) / 2;

	input, button {
		font-size: @font-size;
	}

	input[type="text"], input[type="search"], input[type="email"] {
	  	.mixin-input-height(@font-size, @height-scale);
	}

	button[type="submit"] {
		line-height: @font-size;
		padding-top: @input-padding-vertical;
		padding-bottom: @input-padding-vertical;
	}
}