Document Type
<!DOCTYPE HTML PUBLIC ><!DOCTYPE html>
Use video and audio tags play video and audio
<video controls> <source src="video/video.webm" type="video/webm"/> <source src="video/video.mp4" type="video/mp4"/> </video>
Default value)
Upper left corner, upper right corner, lower right corner, lower left corner.
##CSS’s syntax is changing with each passing day, making many things that could not be done before. Now it can be done very easily. Let’s talk about a few relatively new and powerful CSS functions:
Before CSS3, all we could do were rectangles, boxes, and boxes.
CSS3
Except for the most common rectangles and circles (
border-radius), here are some other geometric shapes:
//01圆角边的css #circle{
width: 300px;
height: 300px;
border: 1px solid red;
border-radius: 10px;
box-shadow: 5px 5px 5px green;
}<div id="circle">我是圆角边的div</div>//02圆形的css加图片#circleshape{
width: 300px;
height: 300px;
border: 1px solid red;
border-radius: 150px;
background: url("img/001.jpg") 0px 0px no-repeat;
background-size: cover;
opacity: 0.7;
transition: all 5s;
}
#circleshape:hover{
transform: rotate(300deg) scale(1.5);
transition: all 5s linear;
}<div id="circleshape">我是圆形的div</div>//03半圆形的CSS #halfcircle{
width: 300px;
height: 150px;
border: 1px solid red;
border-radius: 150px 150px 0px 0px;
background:linear-gradient(to top,pink,palegreen);
background:radial-gradient(palegoldenrod,palevioletred);
}<div id="halfcircle">我是半圆形的div</div>//04四分之一圆形 #halfcircles{
width: 150px;
height: 150px;
border: 1px solid red;
border-radius: 150px 0px 0px 0px;
}<div id="halfcircles">我是四分之一圆形的div</div>
#halfcircless{
width: 150px;
height: 150px;
border: 1px solid red;
border-radius: 0px 150px 0px 0px;
}<div id="halfcircless">我是四分之一圆形的div</div>
#halfcirclesss{
width: 150px;
height: 150px;
border: 1px solid red;
border-radius: 0px 0px 0px 150px;
}<div id="halfcirclesss">我是四分之一圆形的div</div>#halfcirclessss{
width: 150px;
height: 150px;
border: 1px solid red;
border-radius: 0px 0px 150px 0px;
}<div id="halfcirclessss">我是四分之一圆形的div</div>
#halfcircl{
width: 300px;
height: 150px;
border: 1px solid red;
border-radius: 0px 0px 150px 150px;
}<div id="halfcircl">我是半圆形的div</div>//05：三角形 .traingle {
width: 0;
height: 0;
border-left: 50px solid transparent;
border-right: 50px solid transparent;
border-bottom: 100px solid yellowgreen;
}<div class="traingle ">我的三角形，我是div</div>//06：切角:多重线性渐变实现切角。 .notching {
width: 40px;
height: 40px;
padding: 40px;
background: linear-gradient(135deg, transparent 15px, yellowgreen 0) top left,
linear-gradient(-135deg, transparent 15px, yellowgreen 0) top right,
linear-gradient(-45deg, transparent 15px, yellowgreen 0) bottom right,
linear-gradient(45deg, transparent 15px, yellowgreen 0) bottom left;
background-size: 50% 50%;
background-repeat: no-repeat;
}<div class="notching">我是切角，我是div</div>//07：椭圆形 .ellipse {
width: 120px;
height: 160px;
background-color: yellowgreen;
border-radius: 50% 50% 50% 50% / 60% 60% 40% 40%;
}<div class="ellipse">我是椭圆形，我是div</div>08：梯形：伪元素加旋转透视实现梯形
.trapezoid{
position: relative;
width: 60px;
padding: 60px;
}
.trapezoid::before{
content:"";
position: absolute;
top: 0; right: 0; bottom: 0; left: 0;
transform: perspective(20px) scaleY(1.3) rotateX(5deg);
transform-origin: bottom;
background: yellowgreen;
}<div class="trapezoid">我是上面短的梯形，我是div</div>.trapezoids {
position: relative;
width: 60px;
border-top: 60px solid yellowgreen;
border-left: 40px solid transparent;
border-right: 40px solid transparent;
}<div class="trapezoids">我是下面短的梯形，我是div</div>//09.五边形:梯形加上三角形，很容易就组合成一个五边形，这里需要借助一个伪元素实现：.pentagon {
position: relative;
width: 60px;
border-bottom: 60px solid yellowgreen;
border-left: 40px solid transparent;
border-right: 40px solid transparent;
}
.pentagon::before {
content:"";
position: absolute;
top: 60px;
left: -40px;
border-top: 60px solid yellowgreen;
border-left: 70px solid transparent;
border-right: 70px solid transparent;
}//10六边形看看上面的梯形，如果两个反方向且底边同样大小的梯形，叠加在一起，是不是就能得到一个六边形呢
.pentagon {
position: relative;
width: 60px;
border-bottom: 60px solid yellowgreen;
border-left: 40px solid transparent;
border-right: 40px solid transparent;
}
.pentagon::before {
content: "";
position: absolute;
width: 60px;
height: 0px;
top: 60px;
left: -40px;
border-top: 60px solid yellowgreen;
border-left: 40px solid transparent;
border-right: 40px solid transparent;
}//11：八边形六边形都解决了，八边形也不在话下，一个矩形加上两个梯形，可以合成一个八边形。
.octagon {
position: relative;
width: 40px;
height: 100px;
background: yellowgreen;
}
.octagon::before {
content: "";
height: 60px;
position: absolute;
top: 0;
left: 40px;
border-left: 30px solid yellowgreen;
border-top: 20px solid transparent;
border-bottom: 20px solid transparent;
}
.octagon::after {
content: "";
height: 60px;
position: absolute;
top: 0;
left: -30px;
border-right: 30px solid yellowgreen;
border-top: 20px solid transparent;
border-bottom: 20px solid transparent;
}//12：五角星好的，探索完多边形，我们继续探索X角星。
先来看看五角星，要怎么实现呢？当然是直接打出来啦 -- ★☆
.star {
margin: 50px 0;
position: relative;
width: 0;
border-right: 100px solid transparent;
border-bottom: 70px solid yellowgreen;
border-left: 100px solid transparent;
transform: rotate(35deg) scale(.6);
}
.star:before {
content: '';
position: absolute;
border-bottom: 80px solid yellowgreen;
border-left: 30px solid transparent;
border-right: 30px solid transparent;
top: -45px;
left: -65px;
transform: rotate(-35deg);
}
.star:after {
content: '';
position: absolute;
top: 3px;
left: -105px;
border-right: 100px solid transparent;
border-bottom: 70px solid yellowgreen;
border-left: 100px solid transparent;
transform: rotate(-70deg);
}//12：六角星六角星呢？想象一下，一个向上的三角形 ▲，叠加上一个向下的三角形 ▼，就可以得到一个六边形：
.sixstar {
position: relative;
width: 0;
border-left: 50px solid transparent;
border-right: 50px solid transparent;
border-bottom: 100px solid yellowgreen;
}
.sixstar:after {
content: "";
position: absolute;
border-left: 50px solid transparent;
border-right: 50px solid transparent;
border-top: 100px solid yellowgreen;
top: 30px;
left: -50px;
}//13：八角星八角星呢？八个角那么多呢。其实使用两个矩形进行旋转拼接就可以了。
.eightstar {
position: relative;
width: 100px;
height: 100px;
background-color: yellowgreen;
transform: rotate(30deg);
}
.eightstar::before {
content: "";
position: absolute;
top: 0;
left: 0;
width: 100px;
height: 100px;
transform: rotate(45deg);
background-color: yellowgreen;
}//14：十二角星好。最后多角星再来一个十二级角星。在八角星的基础上，再增加一个矩形，就能得到十二角啦。也就是要过第一个伪元素。
.twelvestar {
position: relative;
width: 100px;
height: 100px;
margin-bottom: 100px!important;
background-color: yellowgreen;
transform: rotate(30deg);
}
.twelvestar::before {
content: "";
position: absolute;
top: 0;
left: 0;
width: 100px;
height: 100px;
transform: rotate(30deg);
background-color: yellowgreen;
}
.twelvestar::after {
content: "";
position: absolute;
top: 0;
left: 0;
width: 100px;
height: 100px;
transform: rotate(60deg);
background-color: yellowgreen;
}
#
The above is the detailed content of Examples of usage of CSS+HTML5. For more information, please follow other related articles on the PHP Chinese website!
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
