1.什么是媒体查询 media query
@media screen and (min-width: 900px) {
body {
background-color: red;
}
2. 为什么需要媒体查询
- 一套样式不可能适应各种大小的屏幕
- 针对不同的屏幕大小写样式
- 让我们的页面在不同大小的屏幕上都能正常显示
3.媒体类型
all(default)
@media (min-width: 900px) { 可以省略 and
body {
background-color: red;
}
screen / print / speech
@media print and (min-width: 900px) {
body {
background-color: red;
}
4. 媒体查询中的逻辑
a.与( and )
@media screen and (min-width: 900px) and (max-width: 1024px) {
body {
background-color: red;
}
}
b.或( , )
@media screen and (min-width: 1024px), (max-width: 900px) {
body {
background-color: red;
}
}
@media screen and (min-width: 1024px), screen and (max-width: 900px) {
body {
background-color: red;
}
}
c.非( not )
@media not screen and (min-width: 900px) and (max-width: 1024px) {
body {
background-color: red;
}
}
@media not screen and (min-width: 1024px), screen and (max-width: 900px) {
body {
background-color: red;
}
}
5. 媒体特征表达式
width/max-width/min-width
-webkit-device-pixel-ratio/-webkit-max-device-pixel-ratio/-webkit-min-pixel-ratio
orientation
landscape/portrait
@media (-webkit-max-device-pixel-ratio: 2) and (orientation: landscape) {
body {
background-color: red;
}
}
height
device-width/device-height
screen.width/screen.height
aspect-ratio 视口的宽高比