我一直在做一些关于媒体查询的研究，但我仍然不太明白如何针对特定尺寸的设备。
我希望能够瞄准台式机、平板电脑和手机。我知道会有一些差异，但如果有一个通用的系统可以用来针对这些设备就好了。
我找到了一些例子:
# 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)
Or:
# 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?
当前回答
Extra small devices (phones, up to 480px) Small devices (tablets, 768px and up) Medium devices (big landscape tablets, laptops, and desktops, 992px and up) Large devices (large desktops, 1200px and up) portrait e-readers (Nook/Kindle), smaller tablets - min-width:481px portrait tablets, portrait iPad, landscape e-readers - min-width:641px tablet, landscape iPad, lo-res laptops - min-width:961px HTC One device-width: 360px device-height: 640px -webkit-device-pixel-ratio: 3 Samsung Galaxy S2 device-width: 320px device-height: 534px -webkit-device-pixel-ratio: 1.5 (min--moz-device-pixel-ratio: 1.5), (-o-min-device-pixel-ratio: 3/2), (min-device-pixel-ratio: 1.5 Samsung Galaxy S3 device-width: 320px device-height: 640px -webkit-device-pixel-ratio: 2 (min--moz-device-pixel-ratio: 2), - Older Firefox browsers (prior to Firefox 16) - Samsung Galaxy S4 device-width: 320px device-height: 640px -webkit-device-pixel-ratio: 3 LG Nexus 4 device-width: 384px device-height: 592px -webkit-device-pixel-ratio: 2 Asus Nexus 7 device-width: 601px device-height: 906px -webkit-min-device-pixel-ratio: 1.331) and (-webkit-max-device-pixel-ratio: 1.332) iPad 1 and 2, iPad Mini device-width: 768px device-height: 1024px -webkit-device-pixel-ratio: 1 iPad 3 and 4 device-width: 768px device-height: 1024px -webkit-device-pixel-ratio: 2) iPhone 3G device-width: 320px device-height: 480px -webkit-device-pixel-ratio: 1) iPhone 4 device-width: 320px device-height: 480px -webkit-device-pixel-ratio: 2) iPhone 5 device-width: 320px device-height: 568px -webkit-device-pixel-ratio: 2)
其他回答
不要针对特定的设备或尺寸!
一般的智慧不是针对特定的设备或大小，而是重新定义术语“断点”:
首先使用百分比或ems开发移动网站，而不是像素， 然后在一个更大的视口中尝试，注意它开始失败的地方， 重新设计布局，并添加CSS媒体查询，只是为了处理破碎的部分， 重复此过程，直到到达下一个断点。
您可以使用responsivepx.com找到“自然的”断点，如Marc Drummond所写的“断点已死”。
使用自然断点
“断点”将成为你的手机设计开始“崩溃”的实际点，即不再可用或在视觉上令人愉悦。一旦你有了一个运行良好的移动网站，没有媒体查询，你就可以不再关心具体的大小，只需添加媒体查询来处理连续较大的视口。
如果你不打算将设计固定在精确的屏幕尺寸上，这种方法就不需要针对特定的设备。设计本身在每个断点上的完整性确保了它在任何大小下都能保持不变。换句话说，如果一个菜单/内容部分或任何东西在某个大小时停止可用，为该大小设计一个断点，而不是为特定的设备大小设计一个断点。
请参阅Lyza Gardner关于行为断点的帖子，以及Zeldman关于Ethan Marcotte以及响应式网页设计如何从最初的想法演变而来的帖子。
使用语义标记
此外，DOM结构的nav, header, main, section, footer等语义越简单(避免像div class="header"嵌套内部div标签)，就越容易设计响应性，特别是通过使用CSS Grid Layout避免浮动(Sarah Drasner的网格生成器是一个很好的工具)和flexbox根据您的RWD设计计划安排和重新排序。
在我看来，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:改进工作更好的960网格:
@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 */ }
在实践中，许多设计师将像素转换为ems，很大程度上是因为ems提供更好的缩放效果。在标准缩放1em == 16px时，将像素乘以1em/16px得到ems。例如，320px === 20em。
对于这条评论的回应，最小宽度是“移动优先”设计的标准，即你从设计最小的屏幕开始，然后添加不断增加的媒体查询，直至越来越大的屏幕。
无论您是喜欢min-、max-还是它们的组合，都要认识到规则的顺序，记住，如果多个规则匹配同一个元素，后面的规则将覆盖前面的规则。
一个额外的特性是您还可以在<link>标记的media属性中使用media-queries。
<link href="style.css" rel="stylesheet">
<link href="justForFrint.css" rel="stylesheet" media="print">
<link href="deviceSizeDepending.css" rel="stylesheet" media="(min-width: 40em)">
这样，浏览器将下载所有CSS资源，而不考虑介质属性。 区别在于，如果media属性的media-query被赋值为false，那么.css文件及其内容将不会被渲染阻塞。
因此，建议在<link>标签中使用media属性，可以保证更好的用户体验。
在这里你可以阅读谷歌关于这个问题的文章https://developers.google.com/web/fundamentals/performance/critical-rendering-path/render-blocking-css
一些工具，将帮助您自动分离您的css代码在不同的文件根据您的媒体查询
Webpack https://www.npmjs.com/package/media-query-plugin https://www.npmjs.com/package/media-query-splitting-plugin
PostCSS https://www.npmjs.com/package/postcss-extract-media-query
如果你想创建更具体的媒体查询，这里有一个IPhone的例子，从这个链接https://css-tricks.com/snippets/css/media-queries-for-standard-devices/复制，你可以在这个链接中找到更多设备的媒体查询)
/* ----------- iPhone 4 and 4S ----------- */ /* Portrait and Landscape */ @media only screen and (min-device-width: 320px) and (max-device-width: 480px) and (-webkit-min-device-pixel-ratio: 2) { } /* Portrait */ @media only screen and (min-device-width: 320px) and (max-device-width: 480px) and (-webkit-min-device-pixel-ratio: 2) and (orientation: portrait) { } /* Landscape */ @media only screen and (min-device-width: 320px) and (max-device-width: 480px) and (-webkit-min-device-pixel-ratio: 2) and (orientation: landscape) { } /* ----------- iPhone 5, 5S, 5C and 5SE ----------- */ /* Portrait and Landscape */ @media only screen and (min-device-width: 320px) and (max-device-width: 568px) and (-webkit-min-device-pixel-ratio: 2) { } /* Portrait */ @media only screen and (min-device-width: 320px) and (max-device-width: 568px) and (-webkit-min-device-pixel-ratio: 2) and (orientation: portrait) { } /* Landscape */ @media only screen and (min-device-width: 320px) and (max-device-width: 568px) and (-webkit-min-device-pixel-ratio: 2) and (orientation: landscape) { } /* ----------- iPhone 6, 6S, 7 and 8 ----------- */ /* Portrait and Landscape */ @media only screen and (min-device-width: 375px) and (max-device-width: 667px) and (-webkit-min-device-pixel-ratio: 2) { } /* Portrait */ @media only screen and (min-device-width: 375px) and (max-device-width: 667px) and (-webkit-min-device-pixel-ratio: 2) and (orientation: portrait) { } /* Landscape */ @media only screen and (min-device-width: 375px) and (max-device-width: 667px) and (-webkit-min-device-pixel-ratio: 2) and (orientation: landscape) { } /* ----------- iPhone 6+, 7+ and 8+ ----------- */ /* Portrait and Landscape */ @media only screen and (min-device-width: 414px) and (max-device-width: 736px) and (-webkit-min-device-pixel-ratio: 3) { } /* Portrait */ @media only screen and (min-device-width: 414px) and (max-device-width: 736px) and (-webkit-min-device-pixel-ratio: 3) and (orientation: portrait) { } /* Landscape */ @media only screen and (min-device-width: 414px) and (max-device-width: 736px) and (-webkit-min-device-pixel-ratio: 3) and (orientation: landscape) { } /* ----------- iPhone X ----------- */ /* Portrait and Landscape */ @media only screen and (min-device-width: 375px) and (max-device-width: 812px) and (-webkit-min-device-pixel-ratio: 3) { } /* Portrait */ @media only screen and (min-device-width: 375px) and (max-device-width: 812px) and (-webkit-min-device-pixel-ratio: 3) and (orientation: portrait) { } /* Landscape */ @media only screen and (min-device-width: 375px) and (max-device-width: 812px) and (-webkit-min-device-pixel-ratio: 3) and (orientation: landscape) { }
Extra small devices (phones, up to 480px) Small devices (tablets, 768px and up) Medium devices (big landscape tablets, laptops, and desktops, 992px and up) Large devices (large desktops, 1200px and up) portrait e-readers (Nook/Kindle), smaller tablets - min-width:481px portrait tablets, portrait iPad, landscape e-readers - min-width:641px tablet, landscape iPad, lo-res laptops - min-width:961px HTC One device-width: 360px device-height: 640px -webkit-device-pixel-ratio: 3 Samsung Galaxy S2 device-width: 320px device-height: 534px -webkit-device-pixel-ratio: 1.5 (min--moz-device-pixel-ratio: 1.5), (-o-min-device-pixel-ratio: 3/2), (min-device-pixel-ratio: 1.5 Samsung Galaxy S3 device-width: 320px device-height: 640px -webkit-device-pixel-ratio: 2 (min--moz-device-pixel-ratio: 2), - Older Firefox browsers (prior to Firefox 16) - Samsung Galaxy S4 device-width: 320px device-height: 640px -webkit-device-pixel-ratio: 3 LG Nexus 4 device-width: 384px device-height: 592px -webkit-device-pixel-ratio: 2 Asus Nexus 7 device-width: 601px device-height: 906px -webkit-min-device-pixel-ratio: 1.331) and (-webkit-max-device-pixel-ratio: 1.332) iPad 1 and 2, iPad Mini device-width: 768px device-height: 1024px -webkit-device-pixel-ratio: 1 iPad 3 and 4 device-width: 768px device-height: 1024px -webkit-device-pixel-ratio: 2) iPhone 3G device-width: 320px device-height: 480px -webkit-device-pixel-ratio: 1) iPhone 4 device-width: 320px device-height: 480px -webkit-device-pixel-ratio: 2) iPhone 5 device-width: 320px device-height: 568px -webkit-device-pixel-ratio: 2)
