bootStrap @media 用法

一. @media 格式

@media all and (min-width:xxx) and (max-width:xxx) (亦可以写成@media all and (min-width:xxx) and (max-width:xxx)) {
/*这段查询的all是针对所有设备(有些设备不一定是屏幕，也许是打字机，盲人阅读器)*/
}

@media only screen and (min-width:xxx) and (max-width:xxx){
/*上面针对了所有设备，这段是只(only)针对彩色屏幕设备*/
}

@media only screen and (min-width:1024px) and (max-width:1292px){
    body div{
        font-size:30px;
        color:red;
    }
}