.xia {
     display: flex;
     flex-direction: column;
     box-sizing: border-box;
   }


   .you {
     display: flex;
     flex-direction: row;
     box-sizing: border-box;

   }

   .zon {
     display: flex;
     justify-content: center;
     align-items: center;
   }


   

   .铺满 {
     width: 100%;
     height: 100%;
   }

   .原位 {
     position: absolute;
     top: 0;
     left: 0;
   }

   .正比 {
     aspect-ratio: 1 / 1;
   }

   .文本限制长度 {
     overflow: hidden;
     white-space: nowrap;
     /* text-overflow: ellipsis; */
   }

   .禁用框选文本 {
     user-select: none;
     -webkit-user-select: none;
     -moz-user-select: none;
     -ms-user-select: none;
   }

   /* ////////////////////////////////////////////// */
   body {
     display: flex;
     justify-content: center;
     align-items: center;
     min-height: 100vh;
     height: 100vh;
     box-sizing: border-box;
     margin: 0;
     overflow: hidden;

     user-select: none;
     -webkit-user-select: none;
     -moz-user-select: none;
     -ms-user-select: none;
   }

   :root {
     --sf: 1
   }

   /* const sf=getComputedStyle(document.documentElement).getPropertyValue('--sf');
        const sfValue=parseFloat(sf); */

   /* //////////////////////////////////////// */