前端（各種demo）一：css實現三角形，css實現梯形，pop彈層，css偽類before，after使用，svg使用（持續更新中）

文章出處

各種demo：

1、css實現正方形

思路：width為0；height為0；使用boder-width為正方形的邊長的一半，不占任何字節；border-style為固體；border-color為正方形的填充色。

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title></title>
        <style type="text/css">
            .triangle{
                width: 0;
                height: 0;
                border-width: 30px;
                border-style: solid;
                border-color:#e66161; 
            }
        </style>
    </head>
    <body>
        <div class="triangle"></div>
    </body>
</html>

圖形

2、css實現三角形

思路：寬度width為0；height為0；border-width為直角三角形斜邊的一半；border-color里有四個顏色屬性，第一個為上--直角三角形內充填充色，第二個為右--直角三角形內填充色，第三個為下--直角三角形內填充色，第四個為左--直角三角形內填充色。

代碼：

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title></title>
        <style type="text/css">
            .triangle{
                width: 0;
                height: 0;
                border-width: 30px;
                border-style: solid;
                border-color: #000000 transparent transparent transparent;
            }
        </style>
    </head>
    <body>
        <div class="triangle"></div>
    </body>
</html>

圖形

代碼：

.triangle{
                width: 0;
                height: 0;
                border-width: 30px;
                border-style: solid;
                border-color: #000000 #000000 transparent transparent;
            }

圖形

代碼：

.triangle{
                width: 0;
                height: 0;
                border-width: 30px;
                border-style: solid;
                border-color: #000000 #f50303 transparent transparent;
            }

圖形

3、css實現正方形外梯形

思路：還是之前的思路，width為20；高度為20；梯形的短底邊為div的width；梯形的長邊=width+border-width*2；

代碼：

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title></title>
        <style type="text/css">
            .triangle{
                width: 20px;
                height: 20px;
                border-width:30px;
                border-style: solid;
                border-color: #000000 transparent transparent transparent;
            }
        </style>
    </head>
    <body>
        <div class="triangle"></div>
    </body>
</html>

圖形：

代碼：

.triangle{
                width: 0;
                height: 0;
                border-width: 30px;
                border-style: solid;
                border-color:#e66161 #f3bb5b #94e24f #85bfda;
            }

圖形：

4、css實現pop彈層

思路：利用兩個三角形進行拼接，一個是背景色，一個是邊框色，然后利用定位重疊在一起，定位要相差一個像素。

代碼：

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title></title>
        <style type="text/css">
            .box{
                position: relative;
                width: 240px;
                height: 60px;
                line-height: 60px;
                background: #e9fbe4;
                box-shadow: 1px 2px 3px #e9fbe4;
                border: 1px solid #c9e9c0;
                border-radius: 4px;
                text-align: center;
                color: #0c7823;
            }
            .triangle-border{
                width: 0;
                height: 0;
                border-width: 10px;
                border-style: solid;
                position: absolute;
                left: 30px;
                overflow: hidden;
                
            }
            .border{
                bottom:-20px;
                border-color: #C9E9C0 transparent transparent transparent;
            }
            .background{
                bottom: -19px;
                border-color: #E9FBE4 transparent transparent transparent;
            }
        </style>
    </head>
    <body>
        <div class="box">
            <span>我是利用border屬性實現</span>
            <div class="triangle-border border"></div>
            <div class="triangle-border background"></div>
        </div>
    </body>
</html>

5、css實現字體漸變色

5.1使用gradient屬性

存在的不足：IE瀏覽器都不支持。

<!DOCTYPE html>
<html>

    <head>
        <meta charset="utf-8" />
        <title></title>
        <style type="text/css">
            .promotion-floor-title {
                text-align: center;
                margin: 60px auto 40px;
            }
            
            .promotion-floor-title .title p {
                display: inline-block;
                text-align: center;
                font-size: 42px;
                background-image: -webkit-gradient(linear, 0 0, 0 bottom, from(#2ED4FB), to(#236BEC));
                -webkit-background-clip: text;
                -webkit-text-fill-color: transparent;
            }
        </style>
    </head>

    <body>
        <div class="promotion-floor-title">
            <div class="title">
                <p>Hello</p>
            </div>
        </div>

    </body>

</html>

5.2使用svg，支持IE9以及以上

<!DOCTYPE html>
<html>

    <head>
        <meta charset="utf-8" />
        <title></title>
        <style type="text/css">
            .promotion-floor-title {
                text-align: center;
                margin: 60px auto 40px;
            }
            
            .promotion-floor-title .title {
                min-width: 590px;
                height: 41px;
                display: inline-block;
                position: relative;
            }
            
            .promotion-floor-title .title svg {
                margin: 0 223px;
                height: 41px;
            }
        </style>
    </head>

    <body>
        <div class="promotion-floor-title">
            <div class="title">
                <svg xmlns="http://www.w3.org/2000/svg" version="1.1">
                    <linearGradient id="grad1" x1="0%" y1="0%" x2="100%" y2="0%">
                        <stop offset="0%" style="stop-color:#2ED4FB;stop-opacity:1" />
                        <stop offset="100%" style="stop-color:#236BEC;stop-opacity:1" />
                    </linearGradient>
                    <text text-anchor="middle" x="50%" y="50%" dy=".36em" class="text" font-size="3.6rem" fill="url(#grad1)">Hello</text>
                </svg>
            </div>
        </div>
    </body>

</html>

6、css實現一條線

思路：使用span標簽，不占文檔流，使用背景色background是線條顏色，定位使用position=absolute也是脫離原先的文檔流，最主要的是設置高度height為1px，設置使用top來定位，以及寬度來限制線的長度。

<!DOCTYPE html>
<html>

    <head>
        <meta charset="utf-8" />
        <title></title>
        <style type="text/css">
            .promotion-floor-title {
                text-align: center;
                margin: 60px auto 40px;
            }
            
            .promotion-floor-title .title {
                min-width: 590px;
                height: 41px;
                display: inline-block;
                position: relative;
            }
            
            .promotion-floor-title .title svg {
                margin: 0 223px;
                height: 41px;
            }
            
            .promotion-floor-title .title span {
                background: #5672EB;
                position: absolute;
                height: 1px;
                width: 28%;
                top: 50%;
            }
            
            .promotion-floor-title .title .left-line {
                left: 0;
            }
            
            .promotion-floor-title .title .right-line {
                right: 0;
            }
            
        </style>
    </head>

    <body>
        <div class="promotion-floor-title">
            <div class="title">
                <svg xmlns="http://www.w3.org/2000/svg" version="1.1">
                    <linearGradient id="grad1" x1="0%" y1="0%" x2="100%" y2="0%">
                        <stop offset="0%" style="stop-color:#2ED4FB;stop-opacity:1" />
                        <stop offset="100%" style="stop-color:#236BEC;stop-opacity:1" />
                    </linearGradient>
                    <text text-anchor="middle" x="50%" y="50%" dy=".36em" class="text" font-size="3.6rem" fill="url(#grad1)">Hello</text>
                </svg>
                <span class="left-line"></span>
                <span class="right-line"></span>
            </div>
        </div>
    </body>

</html>

7、css使用偽類after實現旋轉正方形

思路:在span使用偽類after，第一步設置content為""；第二步增加一個width和height相同的值；第三步使用border邊框設定正方形顏色；第四步以及旋轉transform等于rotateZ(45deg)，設置兼容到webkit，moz，ms瀏覽器內核；使用position的absolute脫離原先的文檔流；使用top來進行定位。

代碼：

<!DOCTYPE html>
<html>

    <head>
        <meta charset="utf-8" />
        <title></title>
        <style type="text/css">
            .promotion-floor-title {
                text-align: center;
                margin: 60px auto 40px;
            }
            
            .promotion-floor-title .title {
                min-width: 590px;
                height: 41px;
                display: inline-block;
                position: relative;
            }
            
            .promotion-floor-title .title svg {
                margin: 0 223px;
                height: 41px;
            }
            
            .promotion-floor-title .title span {
                background: #5672EB;
                position: absolute;
                height: 1px;
                width: 28%;
                top: 50%;
            }
            
            .promotion-floor-title .title span:after {
                content: "";
                position: absolute;
                top: -5px;
                height: 9px;
                width: 9px;
                border: 1px solid #5672EB;
                border-radius: 1px;
                transform: rotateZ(45deg);
                -webkit-transform: rotateZ(45deg);
                -moz-transform: rotateZ(45deg);
                -ms-transform: rotateZ(45deg);
            }
            
            .promotion-floor-title .title .left-line {
                left: 0;
            }
            
            .promotion-floor-title .title .left-line:after {
                right: -13px;
            }
            
            .promotion-floor-title .title .right-line {
                right: 0;
            }
            
            .promotion-floor-title .title .right-line:after {
                left: -13px;
            }
        </style>
    </head>

    <body>
        <div class="promotion-floor-title">
            <div class="title">
                <svg xmlns="http://www.w3.org/2000/svg" version="1.1">
                    <linearGradient id="grad1" x1="0%" y1="0%" x2="100%" y2="0%">
                        <stop offset="0%" style="stop-color:#2ED4FB;stop-opacity:1" />
                        <stop offset="100%" style="stop-color:#236BEC;stop-opacity:1" />
                    </linearGradient>
                    <text text-anchor="middle" x="50%" y="50%" dy=".36em" class="text" font-size="3.6rem" fill="url(#grad1)">Hello</text>
                </svg>
                <span class="left-line"></span>
                <span class="right-line"></span>
            </div>
        </div>
    </body>

</html>