目录
1. 移动端基础
1.1 浏览器现状
1.2 手机屏幕现状
1.3 常见移动端屏幕尺寸
1.4 移动端调试方法
2. 视口
3. 二倍图
3.1 物理像素&物理像素比
3.2 多倍图
3.3 背景缩放
3.4 多倍图切图cutterman
4. 移动端开发选择
4.1 主流方案
4.2 单独制作
4.3 响应式兼容
5. 移动端技术解决方案
5.1 移动端浏览器
5.2 CSS初始化
5.3 CSS3盒子模型box-sizing
5.4 特殊样式
6. 移动端常见布局
6.1 流式布局（百分比布局）
京东案例
1. 移动端基础
1.1 浏览器现状
1.2 手机屏幕现状
1.3 常见移动端屏幕尺寸
1.4 移动端调试方法
总结
2. 视口
3. 二倍图
3.1 物理像素&物理像素比
3.2 多倍图
3.3 背景缩放
/* 1.只写一个参数，肯定是宽度 高度省略了 会等比例缩放 *//* background-size: 500px; *//* 2.单位可以跟百分比 *//* background-size: 50%; *//* 3.cover 等比例拉伸，要完全覆盖盒子，可能有部分显示不全 *//* background-size: cover; *//* 4.高度宽度等比例拉伸 当宽度或高度铺满div盒子就不再进行拉伸 可能有部分空白区域 */background-size: contain;}3.4 多倍图切图cutterman
4. 移动端开发选择
4.1 主流方案
4.2 单独制作
4.3 响应式兼容
5. 移动端技术解决方案
5.1 移动端浏览器
5.2 CSS初始化
5.3 CSS3盒子模型box-sizing
5.4 特殊样式
6. 移动端常见布局
6.1 流式布局（百分比布局）
京东案例
index.html
<!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8"><meta name="viewport"content="width=device-width, initial-scale=1.0,maximum-scale=1.0,minimum-scale=1.0,user-scalable=no"><title>Document</title><!-- 引入CSS初始化文件 --><link rel="stylesheet" href="css/normalize.css"><!-- 引入首页的CSS --><link rel="stylesheet" href="css/index.css">
</head><body><!-- 顶部 --><header class="app"><ul><li><img src="images/close.png" alt=""></li><li><img src="images/logo.png" alt=""></li><li>打开京东app</li><li>立即打开</li></ul></header><!-- 搜索 --><div class="search-wrap"><div class="search-btn"></div><div class="search"><div class="jd-icon"></div><div class="sou"></div></div><div class="search-login">登录</div></div><!-- 主题内容部分 --><div class="main-content"><!-- 滑动图 --><div class="slider"><img src="upload/banner.dpg" alt=""></div><!-- 品牌日 --><div class="brand"><a href="#"><div><img src="upload/pic11.dpg" alt=""></div></a><a href="#"><div><img src="upload/pic22.dpg" alt=""></div></a><a href="#"><div><img src="upload/pic33.dpg" alt=""></div></a></div><!-- nav部分 --><nav><a href=""><img src="upload/nav1.webp" alt=""><span>京东超市</span></a><a href=""><img src="upload/nav2.webp" alt=""><span>京东超市</span></a><a href=""><img src="upload/nav3.webp" alt=""><span>京东超市</span></a><a href=""><img src="upload/nav1.webp" alt=""><span>京东超市</span></a><a href=""><img src="upload/nav1.webp" alt=""><span>京东超市</span></a><a href=""><img src="upload/nav1.webp" alt=""><span>京东超市</span></a><a href=""><img src="upload/nav1.webp" alt=""><span>京东超市</span></a><a href=""><img src="upload/nav1.webp" alt=""><span>京东超市</span></a><a href=""><img src="upload/nav1.webp" alt=""><span>京东超市</span></a><a href=""><img src="upload/nav1.webp" alt=""><span>京东超市</span></a></nav><!-- 新闻模块 --><div class="news"><a href="#"><img src="upload/new1.dpg" alt=""></a><a href="#"><img src="upload/new2.dpg" alt=""></a><a href="#"><img src="upload/new3.dpg" alt=""></a></div></div>
</body></html>index.css
* {margin: 0;padding: 0;
}body {width: 100%;min-width: 320px;max-width: 640px;margin: 0 auto;font-family: -apple-system, Helvetica, sans-serif;font-size: 14px;color: #666;line-height: 1.5;
}.app {height: 45px;
}/* ul {margin: 0;padding: 0;
} */
img {/* 清除图片底部空白缝隙 */vertical-align: middle;
}.app ul li {float: left;height: 45px;background-color: #333;list-style: none;text-align: center;line-height: 45px;color: #fff;
}.app ul li:nth-child(1) {width: 8%;
}.app ul li:nth-child(1) img {width: 10px;
}.app ul li:nth-child(2) {width: 10%;
}.app ul li:nth-child(2) img {width: 30px;/* 和基线对齐，文字或图片小可以居中，行内块元素用vertical-align: middle;实现居中对齐 */vertical-align: middle;
}.app ul li:nth-child(3) {width: 57%;
}.app ul li:nth-child(4) {width: 25%;background-color: #F63515;
}/* 搜索 */
.search-wrap {/* 加了固定定位的盒子要给宽 最好再设置过一遍min-width max-width */position: fixed;/* 给父级添加 overflow: hidden; 避免外边距合并问题 */overflow: hidden;width: 100%;height: 44px;min-width: 320px;max-width: 640px;
}.search-btn {position: absolute;top: 0;left: 0;width: 40px;height: 44px;
}.search-btn::before {content: "";display: block;width: 20px;height: 18px;background: url(../images/s-btn.png) no-repeat;background-size: 20px 18px;margin: 14px 0 0 15px;
}.search-login {position: absolute;right: 0;top: 0;width: 40px;height: 44px;color: #fff;line-height: 44px;
}.search {position: relative;height: 30px;margin: 7px 50px;border-radius: 15px;background-color: #fff;
}.jd-icon {width: 20px;height: 15px;position: absolute;top: 8px;left: 13px;background: url(../images/jd.png) no-repeat;background-size: 20px 15px;
}.jd-icon::after {content: "";position: absolute;top: 0;right: -8px;display: block;width: 1px;height: 15px;background-color: #ccc;
}.sou {position: absolute;top: 8px;left: 50px;width: 18px;height: 15px;background: url(../images/jd-sprites.png) no-repeat -81px 0;background-size: 200px auto;
}.slider img {width: 100%;
}/* 品牌日 */
.brand {overflow: hidden;border-radius: 10px 10px 0 0;
}.brand div {float: left;width: 33.3333%;
}.brand div img {width: 100%;
}/* nav */
nav {padding-top: 5px;
}nav a {float: left;width: 20%;text-align: center;text-decoration: none;color: #666;
}nav a img {width: 40px;margin: 10px 0;
}nav a span {display: block;
}/* news */
.news {margin-top: 20px;
}.news img {width: 100%;
}.news a {float: left;box-sizing: border-box;
}.news a:nth-child(1) {width: 50%;
}/* 从第2个往后选 */
.news a:nth-child(n+2) {width: 25%;border-left: 2px solid #ccc;
}normalize.css
/*! normalize.css v5.0.0 | MIT License | github.com/necolas/normalize.css *//*** 1. Change the default font family in all browsers (opinionated).* 2. Correct the line height in all browsers.* 3. Prevent adjustments of font size after orientation changes in* IE on Windows Phone and in iOS.*//* Document========================================================================== */html {font-family: sans-serif; /* 1 */line-height: 1.15; /* 2 */-ms-text-size-adjust: 100%; /* 3 */-webkit-text-size-adjust: 100%; /* 3 */
}/* Sections========================================================================== *//*** Remove the margin in all browsers (opinionated).*/body {margin: 0;
}/*** Add the correct display in IE 9-.*/article,
aside,
footer,
header,
nav,
section {display: block;
}/*** Correct the font size and margin on `h1` elements within `section` and* `article` contexts in Chrome, Firefox, and Safari.*/h1 {font-size: 2em;margin: 0.67em 0;
}/* Grouping content========================================================================== *//*** Add the correct display in IE 9-.* 1. Add the correct display in IE.*/figcaption,
figure,
main { /* 1 */display: block;
}/*** Add the correct margin in IE 8.*/figure {margin: 1em 40px;
}/*** 1. Add the correct box sizing in Firefox.* 2. Show the overflow in Edge and IE.*/hr {box-sizing: content-box; /* 1 */height: 0; /* 1 */overflow: visible; /* 2 */
}/*** 1. Correct the inheritance and scaling of font size in all browsers.* 2. Correct the odd `em` font sizing in all browsers.*/pre {font-family: monospace, monospace; /* 1 */font-size: 1em; /* 2 */
}/* Text-level semantics========================================================================== *//*** 1. Remove the gray background on active links in IE 10.* 2. Remove gaps in links underline in iOS 8+ and Safari 8+.*/a {background-color: transparent; /* 1 */-webkit-text-decoration-skip: objects; /* 2 */
}/*** Remove the outline on focused links when they are also active or hovered* in all browsers (opinionated).*/a:active,
a:hover {outline-width: 0;
}/*** 1. Remove the bottom border in Firefox 39-.* 2. Add the correct text decoration in Chrome, Edge, IE, Opera, and Safari.*/abbr[title] {border-bottom: none; /* 1 */text-decoration: underline; /* 2 */text-decoration: underline dotted; /* 2 */
}/*** Prevent the duplicate application of `bolder` by the next rule in Safari 6.*/b,
strong {font-weight: inherit;
}/*** Add the correct font weight in Chrome, Edge, and Safari.*/b,
strong {font-weight: bolder;
}/*** 1. Correct the inheritance and scaling of font size in all browsers.* 2. Correct the odd `em` font sizing in all browsers.*/code,
kbd,
samp {font-family: monospace, monospace; /* 1 */font-size: 1em; /* 2 */
}/*** Add the correct font style in Android 4.3-.*/dfn {font-style: italic;
}/*** Add the correct background and color in IE 9-.*/mark {background-color: #ff0;color: #000;
}/*** Add the correct font size in all browsers.*/small {font-size: 80%;
}/*** Prevent `sub` and `sup` elements from affecting the line height in* all browsers.*/sub,
sup {font-size: 75%;line-height: 0;position: relative;vertical-align: baseline;
}sub {bottom: -0.25em;
}sup {top: -0.5em;
}/* Embedded content========================================================================== *//*** Add the correct display in IE 9-.*/audio,
video {display: inline-block;
}/*** Add the correct display in iOS 4-7.*/audio:not([controls]) {display: none;height: 0;
}/*** Remove the border on images inside links in IE 10-.*/img {border-style: none;
}/*** Hide the overflow in IE.*/svg:not(:root) {overflow: hidden;
}/* Forms========================================================================== *//*** 1. Change the font styles in all browsers (opinionated).* 2. Remove the margin in Firefox and Safari.*/button,
input,
optgroup,
select,
textarea {font-family: sans-serif; /* 1 */font-size: 100%; /* 1 */line-height: 1.15; /* 1 */margin: 0; /* 2 */
}/*** Show the overflow in IE.* 1. Show the overflow in Edge.*/button,
input { /* 1 */overflow: visible;
}/*** Remove the inheritance of text transform in Edge, Firefox, and IE.* 1. Remove the inheritance of text transform in Firefox.*/button,
select { /* 1 */text-transform: none;
}/*** 1. Prevent a WebKit bug where (2) destroys native `audio` and `video`* controls in Android 4.* 2. Correct the inability to style clickable types in iOS and Safari.*/button,
html [type="button"], /* 1 */
[type="reset"],
[type="submit"] {-webkit-appearance: button; /* 2 */
}/*** Remove the inner border and padding in Firefox.*/button::-moz-focus-inner,
[type="button"]::-moz-focus-inner,
[type="reset"]::-moz-focus-inner,
[type="submit"]::-moz-focus-inner {border-style: none;padding: 0;
}/*** Restore the focus styles unset by the previous rule.*/button:-moz-focusring,
[type="button"]:-moz-focusring,
[type="reset"]:-moz-focusring,
[type="submit"]:-moz-focusring {outline: 1px dotted ButtonText;
}/*** Change the border, margin, and padding in all browsers (opinionated).*/fieldset {border: 1px solid #c0c0c0;margin: 0 2px;padding: 0.35em 0.625em 0.75em;
}/*** 1. Correct the text wrapping in Edge and IE.* 2. Correct the color inheritance from `fieldset` elements in IE.* 3. Remove the padding so developers are not caught out when they zero out* `fieldset` elements in all browsers.*/legend {box-sizing: border-box; /* 1 */color: inherit; /* 2 */display: table; /* 1 */max-width: 100%; /* 1 */padding: 0; /* 3 */white-space: normal; /* 1 */
}/*** 1. Add the correct display in IE 9-.* 2. Add the correct vertical alignment in Chrome, Firefox, and Opera.*/progress {display: inline-block; /* 1 */vertical-align: baseline; /* 2 */
}/*** Remove the default vertical scrollbar in IE.*/textarea {overflow: auto;
}/*** 1. Add the correct box sizing in IE 10-.* 2. Remove the padding in IE 10-.*/[type="checkbox"],
[type="radio"] {box-sizing: border-box; /* 1 */padding: 0; /* 2 */
}/*** Correct the cursor style of increment and decrement buttons in Chrome.*/[type="number"]::-webkit-inner-spin-button,
[type="number"]::-webkit-outer-spin-button {height: auto;
}/*** 1. Correct the odd appearance in Chrome and Safari.* 2. Correct the outline style in Safari.*/[type="search"] {-webkit-appearance: textfield; /* 1 */outline-offset: -2px; /* 2 */
}/*** Remove the inner padding and cancel buttons in Chrome and Safari on macOS.*/[type="search"]::-webkit-search-cancel-button,
[type="search"]::-webkit-search-decoration {-webkit-appearance: none;
}/*** 1. Correct the inability to style clickable types in iOS and Safari.* 2. Change font properties to `inherit` in Safari.*/::-webkit-file-upload-button {-webkit-appearance: button; /* 1 */font: inherit; /* 2 */
}/* Interactive========================================================================== *//** Add the correct display in IE 9-.* 1. Add the correct display in Edge, IE, and Firefox.*/details, /* 1 */
menu {display: block;
}/** Add the correct display in all browsers.*/summary {display: list-item;
}/* Scripting========================================================================== *//*** Add the correct display in IE 9-.*/canvas {display: inline-block;
}/*** Add the correct display in IE.*/template {display: none;
}/* Hidden========================================================================== *//*** Add the correct display in IE 10-.*/[hidden] {display: none;
}
1.和基线对齐，文字或图片小可以居中，行内块元素用vertical-align: middle;实现居中对齐
2.加了固定定位的盒子一定要给宽
3.清除图片底部空白缝隙 vertical-align: top/middle;
