1.1024px显屏 @media screen and (max-width : 1024px)

2.800px显屏 @media screen and (max-width : 800px)

iPad横板显屏 @media screen and (max-device-width: 1024px) and (orientation: landscape)

iPad竖板显屏 @media screen and (max-device-width: 768px) and (orientation: portrait)

iPhone 和 Smartphones

@media screen and (min-device-width: 320px) and (min-device-width: 480px) {              
/* 样式写在这 */            }