用 scss 寫出一個 ie 也沒問題的 self-clear

self-clear.scss

@mixin self-clear {
	clear: both;
	&:after {
		content: ".";
		display: block;
		height: 0;
		clear: both;
		visibility: hidden;
	}
	*:first-child+html & { min-height: 1px; } // hack ie7
	* html & { height: 1%; } // hack ie6
}

// example:

.group, .section, section {
	@include self-clear;
}