if( window.innerWidth < 669 ){
	setTimeout(() => {
		let mv_bg = document.createElement('div')
		mv_bg.innerHTML = `<div class="mv-bg"></div>`
		document.querySelector('body').appendChild(mv_bg)
		let mv_bg_style = document.createElement('link')
		mv_bg_style.innerHTML = `<link rel="stylesheet" href="http://soul2.cn/example/style/mv-bg.css">`
		document.querySelector('head').appendChild(mv_bg_style)
	}, 1)
}