网站换肤/变灰

https://www.zhangxinxu.com/wordpress/2019/02/link-rel-alternate-website-skin/

// 渲染red.css这个皮肤

document.querySelector('link[href="red.css"]').disabled = false;

//CSS
.gray-filter {
		filter: grayscale(100%);
		-webkit-filter: grayscale(100%);
		-moz-filter: grayscale(100%);
		-ms-filter: grayscale(100%);
		-o-filter: grayscale(100%);
		filter: url("data:image/svg+xml;utf8,<svg xmlns=\'http://www.w3.org/2000/svg\'><filter id=\'grayscale\'><feColorMatrix type=\'matrix\' values=\'0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0 0 0 1 0\'/></filter></svg>#grayscale");
		filter: progid:DXImageTransform.Microsoft.BasicImage(grayscale=1);
		-webkit-filter: grayscale(1);
}
//自动判断
        Specialdate();
	function Specialdate() {
		let today = [new Date().getMonth() + 1, new Date().getDay()].join('-');
		let days = ['12-13'];
		if (days.indexOf(today) > -1) document.body.className = 'gray-filter';
	}