要点：
1.直接只用<header><nav>等CSS3新标签
2.使用新的盒子模型border-box内减式模型，不用再来回设置盒子大小
3.过渡效果和动画效果的联合使用，不考虑兼容
base.css
*{
box-sizing: border-box;
/*全部定义为内减式盒子模型*/
}
a{
text-decoration: none;
}
body{
background-color: #F7F4F4;
}
li{
margin: 0;
padding: 0;
list-style: none;
}
img{
border: 0;
vertical-align: middle;
/*主要是为了解决图片和文字之间的垂直居中问题*/
}
.w{
width: 1200px;
margin: auto;
}
@font-face {
font-family: 'icomoon';
src: url('../fonts/icomoon.eot?rsc7tj');
src: url('../fonts/icomoon.eot?rsc7tj#iefix') format('embedded-opentype'),
url('../fonts/icomoon.ttf?rsc7tj') format('truetype'),
url('../fonts/icomoon.woff?rsc7tj') format('woff'),
url('../fonts/icomoon.svg?rsc7tj#icomoon') format('svg');
font-weight: normal;
font-style: normal;
}
/*引入字体图标,一定要注意调用fonts文件夹路径一定要正确*/
.mySyllabus dl,.mySyllabus dd,.mySyllabus dt{
padding: 0;
margin: 0;
}
.mySyllabus h5,.mySyllabus a,.mySyllabus ul,.mySyllabus li{
padding: 0;
margin: 0;
}
.pro-bd li,.pro-bd ul{
margin: 0;
padding: 0;
}
normalize.css(不好用，建议下次直接使用京东小米的，放在最后)
index.css代码：
header{
width: 1300px;
height: 100px;
margin: 0 auto;
padding-top: 30px;
/*如果是传统盒子的模型，盒子会变大，就要回去将盒子宽高定义的小一点
在base中将所有的元素定义为内减式的盒子模型*/
}
.logo{
width: 195px;
height: 42px;
float: left;
}
.logo a{
display: block;
width: 195px;
height: 42px;
background: url(../img/logo.png) no-repeat;
text-indent: -999px;
overflow: hidden;
/*怕屏幕页面缩小会暴露出来*/
}
nav{
float: left;
}
nav li{
float: left;
height: 40px;
line-height: 40px;
margin-left: 25px;
}
nav li a{
display: block;
height: 40px;
font-size: 18px;
padding: 0 10px;
color: #000;
}
nav li a:hover{
border-bottom: 2px solid #00a4ff;
}
.search{
width: 410px;
height: 40px;
float: left;
margin-left: 80px;
padding-top: 18px;
}
.search input{
width: 361px;
height: 40px;
border: 1px solid #00a4ff;
outline: none;
padding-left: 10px;
float: left;
}
.search button{
width: 49px;
height: 40px;
border: 0;
outline: none;
float: left;
background: url(../img/fa-search.png) no-repeat;
}
.personal{
float: right;
height: 40px;
line-height: 40px;
}
.personal dt,.personal dd{
float: left;
}
.personal s{
position: relative;
padding-right: 30px;
}
.personal s::before{
content: "";
display: block;
position: absolute;
/*这两步基本是必备的选项，因为伪元素默认
是行内的元素，如果要插入一些东西。需要这两个*/
width: 6px;
height: 6px;
right: 13px;
top: 0;
background-color: red;
border-radius: 50%;
}
.personal span img{
border-radius: 50%;
}
/*顶部通栏模块*/
.banner{
height: 420px;
background-color: #1c036c;
}
.inner{
height: 420px;
position: relative;
}
.subnav{
position: absolute;
left: 0;
top: 0;
height: 100%;
width: 190px;
background: rgba(0,0,0,.2);
padding-top: 20px;
}
.subnav a{
font-size: 14px;
color: #fff;
}
.subnav li{
position: relative;
display: block;
}
.subnav i{
font-family: "icomoon";
color: #fff;
font-style: normal;
font-size: 14px;
line-height: 14px;
position: absolute;
top: 0;
right: 20px;
}
.subnav ul li a:hover{
color: #00b4ff;
}
/*侧边栏模块*/
.circle{
width: 176px;
height: 20px;
position: absolute;
left: 50%;
/*margin-left: -88px;*/
transform: translate(-50%);
/*上面注释需要自己计算，这样就水平向左移动了自己盒子的一半
第二个垂直属性不写，其默认为0*/
bottom: 15px;
}
.circle i {
display: inline-block;
width: 13px;
height: 13px;
background: rgba(255,255,255,.4);
margin: 0 5px;
border-radius: 50%;
/*高度的50%如果是正方形，可以形成圆*/
transition: all 0.4s;
}
.circle .current, i:hover{
width: 20px;
border-radius: 6px;
/*这里直接写50%会成椭圆，直接定义为高度的一半，可以形成圆角*/
background-color: #fff;
}
/*侧边栏模块*/
.mySyllabus{
width: 228px;
height: 300px;
position: absolute;
right: 0;
top: 50%;
transform:translateY(-50%);
background-color: #fff;
}
.mySyllabus dl dt{
height: 50px;
background-color: #9bceea;
font-weight: 700;
color: #fff;
line-height: 50px;
font-size: 18px;
text-align: center;
}
.mySyllabus dd{
padding: 15px 20px 0;
}
.mySyllabus dd li{
height: 60px;
border-bottom: 1px solid #ccc;
padding-top: 6px;
}
.mySyllabus dd li:last-child{
border: 0;
}
.mySyllabus h5{
font-size: 15px;
font-weight: normal;
}
.mySyllabus p{
font-size:12px;
}
.mySyllabus .all{
height: 40px;
border: 1px solid #22b0ff;
color: #22b0ff;
display: block;
text-align: center;
line-height: 40px;
font-size: 18px;
}
.mySyllabus .all:hover{
background-color: #22b0ff;
color: #fff;
}
/*导航栏模块*/
.recommend{
margin-top: 10px;
height: 60px;
line-height: 60px;
position: relative;
background-color: #fff;
box-shadow: 0px 1px 12px rgba(0,0,0,.4);
/*阴影非常不好调，可以先在浏览器中，用开发工具写
边试边看效果*/
}
.rec-1{
padding-left: 30px;
}
.rec-1 a{
color: #000;
margin: 0 15px;
font-size: 14px;
}
.rec-1 a:hover{
color: #22b0ff;
}
.rec-1 a:first-child{
color: #22b0ff;
font-size: 14px;
margin-right: 15px;
}
.recommend em{
position: absolute;
right: 56px;
bottom: 0;
font-style: normal;
color: #22b0ff;
}
.pro-hd{
height: 40px;
position: relative;
}
.pro-hd h4{
font-weight: normal;
font-size: 18px;
}
.pro-hd a{
position: absolute;
top: 0;
right: 20px;
}
.pro-bd li{
width: 228px;
height: 270px;
float: left;
margin-right: 15px;
margin-bottom: 15px;
background-color: #fff;
overflow: hidden;
/*隐藏超出盒子部分的图片*/
}
.pro-bd li:hover{
box-shadow: 2px 2px 10px rgba(0,0,0,.3);
transform: translateY(-5px);
}
.pro-bd li:nth-child(5n){
margin-right: 0;
}
/*nth-child(5n)里面这种是表达式，筛选出*5的倍数子孩子*/
.pro-title{
width: 185px;
margin: 20px auto 16px;
font-size: 14px;
color: #050505;
}
.pro-bd p{
width: 185px;
margin: 0 auto;
color: #999;
}
.pro-bd p span{
color: #ff7c2d;
}
.pic img{
transition: all 0.4s;
}
.pic img:hover{
margin-left: -5px;
}
/*为选中图片之后添加动画，那个元素变化，将过渡给那个元素*/
html代码：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>学成在线教育平台——愿每个认真坚持的学子学有所成</title>
<link rel="stylesheet" type="text/css" href="css/normalize.css">
<link rel="stylesheet" type="text/css" href="css/base.css">
<link rel="stylesheet" type="text/css" href="css/index.css">
<link rel="shortcut icon" href="favicon.ico">
<!-- 注意rel代表的是引入的类型，字体图标格式-->
</head>
<body>
<header>
<div class="logo">
<h1><a href="#"></a></h1>
</div>
<nav>
<ul>
<li><a href="#">首页</a></li>
<li><a href="#">课程</a></li>
<li><a href="#">职业规划</a></li>
</ul>
</nav>
<div class="search">
<input type="search" placeholder="请输入关键字">
<button></button>
</div>
<div class="personal">
<dl>
<dt>个人中心</dt>
<dd>
<s><img src="img/ld.png"></s>
<span>
<img src="img/pic.png">
rainbow
</span>
</dd>
</dl>
</div>
</header>
<!-- 头部通栏模块 -->
<div class="banner">
<div class="w inner">
<ul>
<li><a href="#"><img src="img/banner.jpg"></a></li>
</ul>
<div class="subnav">
<ul>
<li><a href="#">前端开发<i></i></a></li>
</ul>
<ul>
<li><a href="#">后端开发</a><i></i></li>
</ul>
<ul>
<li><a href="#">移动开发</a><i></i></li>
</ul>
<ul>
<li><a href="#">人工智能</a><i></i></li>
</ul>
<ul>
<li><a href="#">商业预测</a><i></i></li>
</ul>
<ul>
<li><a href="#">云计算&大数据</a><i></i></li>
</ul>
<ul>
<li><a href="#">运维&测试</a><i></i></li>
</ul>
<ul>
<li><a href="#">UI设计</a><i></i></li>
</ul>
<ul>
<li><a href="#">JAVA</a><i></i></li>
</ul>
<ul>
<li><a href="#">PYHTON</a><i></i></li>
</ul>
<ul>
<li><a href="#">数据结构</a><i></i></li>
</ul>
</div>
<div class="circle">
<i class="current"></i>
<i></i>
<i></i>
<i></i>
<i></i>
<i></i>
</div>
<div class="mySyllabus">
<dl>
<dt>我的课程表</dt>
<dd>
<ul>
<li>
<h5>继续学习 程序语言设计</h5>
<p>上次学到-没有对象</p>
</li>
<li>
<h5>继续学习 数据库详解</h5>
<p>上次学到-删库跑路</p>
</li>
<li>
<h5>继续学习 Linx基础</h5>
<p>上次学到-半截入土</p>
</li>
</ul>
<a href="#" class="all">全部课程</a>
</dd>
</dl>
</div>
</div>
</div>
<!-- 导航栏模块 -->
<div class="recommend w">
<div class="rec-1">
<a href="#">精品推荐</a>|
<a href="#">jQuery</a>|
<a href="#">Spark</a>|
<a href="#">MySQL</a>|
<a href="#">JavaWeb</a>|
<a href="#">Bootstrap</a>|
<a href="#">Node</a>
</div>
<em>修改选修课程</em>
</div>
<div class="products w">
<div class="pro-hd">
<h4>精品推荐</h4>
<a href="#">查看全部</a>
</div>
<div class="pro-bd">
<ul>
<li>
<div class="pic">
<img src="img/hotpic.png">
</div>
<div class="pro-title">
Think PHP 5.0 博客系统实战项目训练
</div>
<p>
<span>高级</span> * 1125人在学
</p>
</li>
<li>
<div class="pic">
<img src="img/tuijianpic.png">
</div>
<div class="pro-title">
Think PHP 5.0 博客系统实战项目训练
</div>
<p>
<span>高级</span> * 1125人在学
</p>
</li>
<li>
<div class="pic">
<img src="img/tuijianpic.png">
</div>
<div class="pro-title">
Think PHP 5.0 博客系统实战项目训练
</div>
<p>
<span>高级</span> * 1125人在学
</p>
</li>
<li>
<div class="pic">
<img src="img/tuijianpic.png">
</div>
<div class="pro-title">
Think PHP 5.0 博客系统实战项目训练
</div>
<p>
<span>高级</span> * 1125人在学
</p>
</li>
<li>
<div class="pic">
<img src="img/tuijianpic.png">
</div>
<div class="pro-title">
Think PHP 5.0 博客系统实战项目训练
</div>
<p>
<span>高级</span> * 1125人在学
</p>
</li>
<li>
<div class="pic">
<img src="img/hotpic.png">
</div>
<div class="pro-title">
Think PHP 5.0 博客系统实战项目训练
</div>
<p>
<span>高级</span> * 1125人在学
</p>
</li>
<li>
<div class="pic">
<img src="img/tuijianpic.png">
</div>
<div class="pro-title">
Think PHP 5.0 博客系统实战项目训练
</div>
<p>
<span>高级</span> * 1125人在学
</p>
</li>
<li>
<div class="pic">
<img src="img/tuijianpic.png">
</div>
<div class="pro-title">
Think PHP 5.0 博客系统实战项目训练
</div>
<p>
<span>高级</span> * 1125人在学
</p>
</li>
<li>
<div class="pic">
<img src="img/tuijianpic.png">
</div>
<div class="pro-title">
Think PHP 5.0 博客系统实战项目训练
</div>
<p>
<span>高级</span> * 1125人在学
</p>
</li>
<li>
<div class="pic">
<img src="img/tuijianpic.png">
</div>
<div class="pro-title">
Think PHP 5.0 博客系统实战项目训练
</div>
<p>
<span>高级</span> * 1125人在学
</p>
</li>
</ul>
</div>
</div>
</body>
</html>效果：
/*! normalize.css v5.0.0 | MIT License | github.com/necolas/normalize.css */
/*
http://necolas.github.io/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;
}