Search form with button search inside of text input

Form.html

<form class="form-search top-left" action="" method="get">
	<span class="sr-only">Search for: </span>
	<input type="text" placeholder="Search..." id="s" name="s">
	<button id="searchsubmit" type="submit"><i class="glyphicon glyphicon-search"></i></button>
</form>

style.less

.form-search {
	@background: white;
	@border-color: @brand-primary;
	@active-background: white;
	@active-border-color: darken(@border-color, 10%);
	@border-radius: 0;
	
	width: 200px;
	position: relative;
	#s {
		border: 1px solid @border-color;
		padding: 5px 40px 5px 15px;
		width: 100%;
		.border-radius(@border-radius);
		background: @background;
	}
	#s:focus {
		background: @active-background;
		border-color: @active-border-color;
	}
	#s:focus+#searchsubmit {
		background: @active-background;
		border-top-color: @active-border-color;
		border-right-color: @active-border-color;
		border-bottom-color: @active-border-color;
	}
	#searchsubmit {
		border: 1px solid @border-color;
		border-left: none;
		position: absolute;
		border-radius: 0 @border-radius @border-radius 0;
		margin-left: -36px;
		padding: 5px 10px;
		background: @background;
		top: 0;
		right: 0;
		height: 100%;
	}
}