使用到的技术
background-image scale
//1pxonRetina//-----------------------------------------------------------------------------.tina(
top:transpant,right:transpant,bottom:transpant,left:transpant,w:1px){mediaonlyscenand(-webkit-min-device-pixel-ratio:2),onlyscenand(min--moz-device-pixel-ratio:2),onlyscenand(-o-min-device-pixel-ratio:2/1),onlyscenand(min-device-pixel-ratio:2),onlyscenand(min-solution:dpi),onlyscenand(min-solution:2dppx){border:none;background-image:-webkit-linear-gradient(deg,top,top50%,transpant50%),-webkit-linear-gradient(deg,right,right50%,transpant50%),-webkit-linear-gradient(90deg,bottom,bottom50%,transpant50%),-webkit-linear-gradient(0,left,left50%,transpant50%);background-image:-moz-linear-gradient(deg,top,top50%,transpant50%),-moz-linear-gradient(deg,right,right50%,transpant50%),-moz-linear-gradient(90deg,bottom,bottom50%,transpant50%),-moz-linear-gradient(0,left,left50%,transpant50%);background-image:-o-linear-gradient(deg,top,top50%,transpant50%),-o-linear-gradient(deg,right,right50%,transpant50%),-o-linear-gradient(90deg,bottom,bottom50%,transpant50%),-o-linear-gradient(0,left,left50%,transpant50%);background-image:linear-gradient(deg,top,top50%,transpant50%),linear-gradient(deg,right,right50%,transpant50%),linear-gradient(0deg,bottom,bottom50%,transpant50%),linear-gradient(90deg,left,left50%,transpant50%);background-size:%w,w%,%w,w%;background-peat:no-peat;background-position:top,righttop,bottom,lefttop;}}.top-1px(color:transpant,w:1px){mediaonlyscenand(-webkit-min-device-pixel-ratio:2),onlyscenand(min--moz-device-pixel-ratio:2),onlyscenand(-o-min-device-pixel-ratio:2/1),onlyscenand(min-device-pixel-ratio:2),onlyscenand(min-solution:dpi),onlyscenand(min-solution:2dppx){border:none;background-image:-webkit-linear-gradient(deg,color,color50%,transpant50%);background-image:-moz-linear-gradient(deg,color,color50%,transpant50%);background-image:-o-linear-gradient(deg,color,color50%,transpant50%);background-image:linear-gradient(deg,color,color50%,transpant50%);background-size:%w;background-peat:no-peat;background-position:top;}}.right-1px(color:transpant,w:1px){mediaonlyscenand(-webkit-min-device-pixel-ratio:2),onlyscenand(min--moz-device-pixel-ratio:2),onlyscenand(-o-min-device-pixel-ratio:2/1),onlyscenand(min-device-pixel-ratio:2),onlyscenand(min-solution:dpi),onlyscenand(min-solution:2dppx){border:none;background-image:-webkit-linear-gradient(deg,color,color50%,transpant50%);background-image:-moz-linear-gradient(deg,color,color50%,transpant50%);background-image:-o-linear-gradient(deg,color,color50%,transpant50%);background-image:linear-gradient(90deg,color,color50%,transpant50%);background-size:w%;background-peat:no-peat;background-position:right;}}.bottom-1px(color:transpant,w:1px){mediaonlyscenand(-webkit-min-device-pixel-ratio:2),onlyscenand(min--moz-device-pixel-ratio:2),onlyscenand(-o-min-device-pixel-ratio:2/1),onlyscenand(min-device-pixel-ratio:2),onlyscenand(min-solution:dpi),onlyscenand(min-solution:2dppx){border:none;background-image:-webkit-linear-gradient(90deg,color,color50%,transpant50%);background-image:-moz-linear-gradient(90deg,color,color50%,transpant50%);background-image:-o-linear-gradient(90deg,color,color50%,transpant50%);background-image:linear-gradient(0,color,color50%,transpant50%);background-size:%w;background-peat:no-peat;background-position:bottom;}}.left-1px(color:transpant,w:1px){mediaonlyscenand(-webkit-min-device-pixel-ratio:2),onlyscenand(min--moz-device-pixel-ratio:2),onlyscenand(-o-min-device-pixel-ratio:2/1),onlyscenand(min-device-pixel-ratio:2),onlyscenand(min-solution:dpi),onlyscenand(min-solution:2dppx){border:none;background-image:-webkit-linear-gradient(0deg,color,color50%,transpant50%);background-image:-moz-linear-gradient(0deg,color,color50%,transpant50%);background-image:-o-linear-gradient(0deg,color,color50%,transpant50%);background-image:linear-gradient(deg,color,color50%,transpant50%);background-size:w%;background-peat:no-peat;background-position:left;}}.border-1px(ratio:2,color,radius:0){position:lative;border:none!important;::after{content:;position:absolute;left:0;top:0;right:(1-ratio)*%;bottom:(1-ratio)*%;border:1pxsolidcolor;border-radius:radius;.transform(scale(1/ratio));.transform-origin(00);pointer-events:none;}}