<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0"> 

@media screen and (orientation: portrait) {
 /*竖屏 css*/
} 
@media screen and (orientation: landscape) {
 /*横屏 css*/
}

@media screen and (orientation: landscape) {
 /*横屏 css*/
}

<link rel="stylesheet" media="all and (orientation:landscape)" href="landscape.css" rel="external nofollow" >

<link rel="stylesheet" media="all and (orientation:portrait)" href="portrait.css" rel="external nofollow" >

//判断手机横竖屏状态：
  window.addEventListener("onorientationchange" in window "orientationchange" : "resize", function() {
    if (window.orientation === 180 || window.orientation === 0) { 
      console.log("竖屏");
      $(".codeIg_s").removeClass('vercreen');//取消横屏样式
    } 
    if (window.orientation === 90 || window.orientation === -90 ){ 
      console.log("横屏");
      $(".codeIg_s").addClass('vercreen');//添加横屏样式
    } 
  }, false);