老师，发现显示在这个地方时，给article设置了宽度，但是好像没有用，图片还是超出了

*{

font-family: Arial;

font-size: 14px;

margin: 0;

padding: 0;

border: none;

}

a {

text-decoration: none;

}

ul{

list-style: none;

}

header{

height: 80px;

background: #000;

}

header > .container{

width: 1200px;

margin: 0 auto;

}

header > .container > a{

display: block;

float: left;

margin: 5px 25px;

}

header > .container > nav{

float: right;

}

header > .container > nav > a{

font-size: 24px;

display: block;

float: left;

height: 73px;

line-height: 73px;

width: 110px;

text-align: center;

color: #fff;

}

header > .container > nav > a.Home{background: #433b90;}

header > .container > nav > a.Course{background: #017fcb;}

header > .container > nav > a.Actual{background: #78b917;}

header > .container > nav > a.Plan{background: #feb800;}

header > .container > nav > a.FAQ{background: #f27c01;}

header > .container > nav > a.Notes{background: #d40112;}

header > .container > nav > a:hover,

header > .container > nav > a.active{

padding-bottom: 7px;

}

.banner{

background: #eaeaea;

}

.banner > ul{

position: relative;

width: 1490px;

height: 538px;

overflow: hidden;/*超出部分隐藏*/

margin: 0 auto;

}

.banner > ul > li{

position: absolute;

width: 610px;

height: 300px;

overflow: hidden;

}

.banner > ul > li.active{

z-index: 2;/*设置层级关系*/

top: 37px;

right: 0;

left: 0;/*居中显示*/

width: 960px;

height: 460px;

margin: auto;

border: 1px solid #fff;

}

.banner > ul > li.left{

z-index: 1;

top: 0;

bottom: 0;

left: 0;

margin: auto;

}

.banner > ul > li.right{

z-index: 1;

top: 0;

right: 0;

bottom: 0;

margin: auto;

}

.banner > ul > li > img{

position: absolute;

left: -30%;

height: 100%;

}

.main{

width: 1200px;

height: 473px;

margin: 34px auto 0;

}

.main h1{

font-size: 30px;

font-weight: lighter;

margin-bottom: 23px;

}

.main h1 > samp {

font-size: 30px;

color: #7c7c7c;

}

.main > aside {

float: left;

width: 450px;

}

.main > article {

float: right;

width: 720px;

overflow: hidden;

}