板式一：
@media screen and (min-width:320px) {
body{font-size:75%;}
}
@media screen and (min-width:480px) {
body{font-size:87.5%;}
}
@media screen and (min-width:540px) {
body{font-size:112.5%;}
}
@media screen and (min-width:550px) {
body{font-size:125%;}
}
@media screen and (min-width:640px) {
body{font-size:150%;}
}
板式二：
@media only screen and (min-width: 1280px){
body{font-size:16px;}
.wai{width:480px;}
}
@media only screen and (min-width: 640px) and (max-width: 1279px){
body{font-size:16px;}
.wai{width:480px;}
}
@media only screen and (min-width: 480px) and (max-width: 639px){
body{font-size:14px;}
.wai{width:100%;}
}
@media only screen and (min-width: 360px) and (max-width: 479px){
body{font-size:12px;}
.wai{width:100%;}
}
@media only screen and (max-width: 360px){
body{font-size:12px;}
.wrapper{width:100%;}
}