以下是完整代码，拷贝到编辑器即可使用
html>
带四角的边框body {
background: #00AB68;
text-align: center;
}
#box {
position: relative;
margin: 120px auto;
width: 400px;
height: 100px;
font-family: KaiTi;
font-size: 18px;
line-height: 100px;
font-weight: bold;
color: #fff;
}
.content {
position: absolute;
width: 100%;
height: 100%;
border: 1px solid #c0c0c0;
}
.content > div {
position: absolute;
width: 10px;
height: 10px;
}
.lt {
left: -3px;
top: -3px;
border-top: 3px solid #c0c0c0;
border-left: 3px solid #c0c0c0;
}
.rt {
right: -3px;
top: -3px;
border-top: 3px solid #c0c0c0;
border-right: 3px solid #c0c0c0;
}
.rb {
bottom: -3px;
right: -3px;
border-bottom: 3px solid #c0c0c0;
border-right: 3px solid #c0c0c0;
}
.lb {
bottom: -3px;
left: -3px;
border-bottom: 3px solid #c0c0c0;
border-left: 3px solid #c0c0c0;
}
人间四月芳菲尽，山寺桃花始盛开。
