我一直在研究媒体查询，但我仍然不太明白如何针对特定大小的设备进行定位。
我想能够针对桌面、平板和手机进行定位。我知道会有一些差异，但有一个通用系统可以用来定位这些设备会很好。
我找到了一些示例：
# Mobile
only screen and (min-width: 480px)
# Tablet
only screen and (min-width: 768px)
# Desktop
only screen and (min-width: 992px)
# Huge
only screen and (min-width: 1280px)
或者：
# Phone
only screen and (max-width:320px)
# Tablet
only screen and (min-width:321px) and (max-width:768px)
# Desktop
only screen and (min-width:769px)
每个设备的断点应该是什么？
我认为这些是最好的断点：
@media (min-width:320px) { /* smartphones, portrait iPhone, portrait 480x320 phones (Android) */ }
@media (min-width:480px) { /* smartphones, Android phones, landscape iPhone */ }
@media (min-width:600px) { /* portrait tablets, portrait iPad, e-readers (Nook/Kindle), landscape 800x480 phones (Android) */ }
@media (min-width:801px) { /* tablet, landscape iPad, lo-res laptops ands desktops */ }
@media (min-width:1025px) { /* big landscape tablets, laptops, and desktops */ }
@media (min-width:1281px) { /* hi-res laptops and desktops */ }
编辑：对于960网格进行了优化：
@media (min-width:320px) { /* smartphones, iPhone, portrait 480x320 phones */ }
@media (min-width:481px) { /* portrait e-readers (Nook/Kindle), smaller tablets @ 600 or @ 640 wide. */ }
@media (min-width:641px) { /* portrait tablets, portrait iPad, landscape e-readers, landscape 800x480 or 854x480 phones */ }
@media (min-width:961px) { /* tablet, landscape iPad, lo-res laptops ands desktops */ }
@media (min-width:1025px) { /* big landscape tablets, laptops, and desktops */ }
@media (min-width:1281px) { /* hi-res laptops and desktops */ }
实际上，许多设计师将像素转换为em，主要是因为em更容易缩放。在标准缩放下，1em === 16px，将像素乘以1em/16px即可得到em。例如，320px === 20em。
针对这个评论，min-width 在“移动优先”的设计中是标准的，你可以从最小屏幕开始设计，然后逐步添加越来越大的媒体查询，扩展到更大的屏幕。
无论你偏好使用 min-、max- 还是两者结合，都要注意你的规则顺序，如果有多条规则匹配同一个元素，则后面的规则会覆盖之前的规则。
min-width: 320px的CSS覆盖min-width: 801px？ - user2019515普遍的智慧是不要针对特定设备或尺寸，而是重新定义“断点”的概念：
您可以使用responsivepx.com找到“自然”的断点，如Marc Drummond所说的'断点已死'。
如果您想针对特定设备进行目标定位，则只需编写min-device-width即可。例如：
@media only screen and (min-device-width: 480px){}
@media only screen and (min-device-width: 768px){}
以下是一些不错的文章:
@media only screen and (min-device-width: 1024){} 或类似的内容来覆盖这些更改。
或者，如果您从桌面设计开始并且只想对小于1024的内容进行更改，则可以执行 @media only screen and (MAX-device-width: 1024){}。 - Steelydevice-width（和 height）已被弃用：https://developer.mozilla.org/en/docs/Web/CSS/@media/device-width - Asons我使用这个网站来查找分辨率和根据实际数字开发CSS。 我的数字与上面的答案相差很大，但我的CSS实际上可以适用于所需的设备。
此外，在媒体查询之后加入这段调试代码，例如：
@media only screen and (min-width: 769px) and (max-width: 1281px) {
/* for 10 inches tablet screens */
body::before {
content: "tablet to some desktop media query (769 > 1281) fired";
font-weight: bold;
display: block;
text-align: center;
background: rgba(255, 255, 0, 0.9); /* Semi-transparent yellow */
position: absolute;
top: 0;
left: 0;
right: 0;
z-index: 99;
}
}
在每个媒体查询中添加此调试项，您将看到应用了哪个查询。
/* Custom, iPhone Retina */
@media only screen and (min-width : 320px) {
}
/* Extra Small Devices, Phones */
@media only screen and (min-width : 480px) {
}
/* Small Devices, Tablets */
@media only screen and (min-width : 768px) {
}
/* Medium Devices, Desktops */
@media only screen and (min-width : 992px) {
}
/* Large Devices, Wide Screens */
@media only screen and (min-width : 1200px) {
}
来源：https://scotch.io/tutorials/default-sizes-for-twitter-bootstraps-media-queries
本文介绍了 Twitter Bootstrap 框架中媒体查询的默认大小。这些媒体查询用于响应式设计，以便在不同的设备上呈现不同的样式。文章详细解释了媒体查询的工作原理，并提供了一张表格来展示默认的媒体查询大小和应用场景。如果你正在使用 Bootstrap 框架开发响应式网站，本文将为你提供有价值的参考。/* Smartphones (portrait and landscape) ----------- */
@media only screen and (min-device-width : 320px) and (max-device-width : 480px) {
/* Styles */
}
/* Smartphones (landscape) ----------- */
@media only screen and (min-width : 321px) {
/* Styles */
}
/* Smartphones (portrait) ----------- */
@media only screen and (max-width : 320px) {
/* Styles */
}
/* iPads (portrait and landscape) ----------- */
@media only screen and (min-device-width : 768px) and (max-device-width : 1024px) {
/* Styles */
}
/* iPads (landscape) ----------- */
@media only screen and (min-device-width : 768px) and (max-device-width : 1024px) and (orientation : landscape) {
/* Styles */
}
/* iPads (portrait) ----------- */
@media only screen and (min-device-width : 768px) and (max-device-width : 1024px) and (orientation : portrait) {
/* Styles */
}
/**********
iPad 3
**********/
@media only screen and (min-device-width : 768px) and (max-device-width : 1024px) and (orientation : landscape) and (-webkit-min-device-pixel-ratio : 2) {
/* Styles */
}
@media only screen and (min-device-width : 768px) and (max-device-width : 1024px) and (orientation : portrait) and (-webkit-min-device-pixel-ratio : 2) {
/* Styles */
}
/* Desktops and laptops ----------- */
@media only screen and (min-width : 1224px) {
/* Styles */
}
/* Large screens ----------- */
@media only screen and (min-width : 1824px) {
/* Styles */
}
/* iPhone 4 ----------- */
@media only screen and (min-device-width : 320px) and (max-device-width : 480px) and (orientation : landscape) and (-webkit-min-device-pixel-ratio : 2) {
/* Styles */
}
@media only screen and (min-device-width : 320px) and (max-device-width : 480px) and (orientation : portrait) and (-webkit-min-device-pixel-ratio : 2) {
/* Styles */
}
/* iPhone 5 ----------- */
@media only screen and (min-device-width: 320px) and (max-device-height: 568px) and (orientation : landscape) and (-webkit-device-pixel-ratio: 2){
/* Styles */
}
@media only screen and (min-device-width: 320px) and (max-device-height: 568px) and (orientation : portrait) and (-webkit-device-pixel-ratio: 2){
/* Styles */
}
/* iPhone 6 ----------- */
@media only screen and (min-device-width: 375px) and (max-device-height: 667px) and (orientation : landscape) and (-webkit-device-pixel-ratio: 2){
/* Styles */
}
@media only screen and (min-device-width: 375px) and (max-device-height: 667px) and (orientation : portrait) and (-webkit-device-pixel-ratio: 2){
/* Styles */
}
/* iPhone 6+ ----------- */
@media only screen and (min-device-width: 414px) and (max-device-height: 736px) and (orientation : landscape) and (-webkit-device-pixel-ratio: 2){
/* Styles */
}
@media only screen and (min-device-width: 414px) and (max-device-height: 736px) and (orientation : portrait) and (-webkit-device-pixel-ratio: 2){
/* Styles */
}
/* Samsung Galaxy S3 ----------- */
@media only screen and (min-device-width: 320px) and (max-device-height: 640px) and (orientation : landscape) and (-webkit-device-pixel-ratio: 2){
/* Styles */
}
@media only screen and (min-device-width: 320px) and (max-device-height: 640px) and (orientation : portrait) and (-webkit-device-pixel-ratio: 2){
/* Styles */
}
/* Samsung Galaxy S4 ----------- */
@media only screen and (min-device-width: 320px) and (max-device-height: 640px) and (orientation : landscape) and (-webkit-device-pixel-ratio: 3){
/* Styles */
}
@media only screen and (min-device-width: 320px) and (max-device-height: 640px) and (orientation : portrait) and (-webkit-device-pixel-ratio: 3){
/* Styles */
}
/* Samsung Galaxy S5 ----------- */
@media only screen and (min-device-width: 360px) and (max-device-height: 640px) and (orientation : landscape) and (-webkit-device-pixel-ratio: 3){
/* Styles */
}
@media only screen and (min-device-width: 360px) and (max-device-height: 640px) and (orientation : portrait) and (-webkit-device-pixel-ratio: 3){
/* Styles */
}
这仅适用于那些尚未将其网站设计为“移动优先”并正在寻找快速临时解决方案的人。
针对手机
@media (max-width:480px){}
针对平板电脑
@media (max-width:960px){}
适用于笔记本电脑/台式机
@media (min-width:1025px){}
适用于高分辨率笔记本电脑
@media (max-width:1280px){}
简洁明了
/* Mobile Devices */
@media (max-width: 480px) {
foo > bar {
}
}
/* Low resolution Tablets and iPads */
@media (min-width: 481px) and (max-width: 767px) {
foo > bar {
}
}
/* Tablets iPads (Portrait) */
@media (min-width: 768px) and (max-width: 1024px){
foo > bar {
}
}
/* Laptops and Desktops */
@media (min-width: 1025px) and (max-width: 1280px){
foo > bar {
}
}
/* Big boi Monitors */
@media (min-width: 1281px) {
foo > bar {
}
}
现在最常见的是看到视网膜屏幕设备，换句话说：具有高分辨率和非常高的像素密度的设备（但通常小于6英寸的物理大小）。这就是为什么您需要在CSS中使用视网膜显示器专用的媒体查询。这是我能找到的最完整的例子：
@media only screen and (min-width: 320px) {
/* Small screen, non-retina */
}
@media
only screen and (-webkit-min-device-pixel-ratio: 2) and (min-width: 320px),
only screen and ( min--moz-device-pixel-ratio: 2) and (min-width: 320px),
only screen and ( -o-min-device-pixel-ratio: 2/1) and (min-width: 320px),
only screen and ( min-device-pixel-ratio: 2) and (min-width: 320px),
only screen and ( min-resolution: 192dpi) and (min-width: 320px),
only screen and ( min-resolution: 2dppx) and (min-width: 320px) {
/* Small screen, retina, stuff to override above media query */
}
@media only screen and (min-width: 700px) {
/* Medium screen, non-retina */
}
@media
only screen and (-webkit-min-device-pixel-ratio: 2) and (min-width: 700px),
only screen and ( min--moz-device-pixel-ratio: 2) and (min-width: 700px),
only screen and ( -o-min-device-pixel-ratio: 2/1) and (min-width: 700px),
only screen and ( min-device-pixel-ratio: 2) and (min-width: 700px),
only screen and ( min-resolution: 192dpi) and (min-width: 700px),
only screen and ( min-resolution: 2dppx) and (min-width: 700px) {
/* Medium screen, retina, stuff to override above media query */
}
@media only screen and (min-width: 1300px) {
/* Large screen, non-retina */
}
@media
only screen and (-webkit-min-device-pixel-ratio: 2) and (min-width: 1300px),
only screen and ( min--moz-device-pixel-ratio: 2) and (min-width: 1300px),
only screen and ( -o-min-device-pixel-ratio: 2/1) and (min-width: 1300px),
only screen and ( min-device-pixel-ratio: 2) and (min-width: 1300px),
only screen and ( min-resolution: 192dpi) and (min-width: 1300px),
only screen and ( min-resolution: 2dppx) and (min-width: 1300px) {
/* Large screen, retina, stuff to override above media query */
}
来源： CSS-Tricks网站
- 如何构建移动网站 - Smashing Magazine
- 如何使用CSS3媒体查询创建移动版本的网站 - Smashing Magazine
- Ahsan Rathod