这是一款超酷的CSS3垂直时间轴特效。该CSS3垂直时间轴特效通过伪元素来制作超酷的半圆形，所有半圆形连接为一条曲线路径，从而组成了时间轴的线路。

使用方法

在页面中引入bootstrap.min.css文件。

HTML结构

该CSS3垂直时间轴的HTML结构如下：

2018

CSS样式

为该CSS3垂直时间轴添加下面的CSS代码。

.main-timeline{    overflow: hidden;    position: relative;}.main-timeline .timeline{    position: relative;    margin-top: -79px;}.main-timeline .timeline:first-child{ margin-top: 0; }.main-timeline .timeline:before,.main-timeline .timeline:after{    content: "";    display: block;    width: 100%;    clear: both;}.main-timeline .timeline:before{    content: "";    width: 100%;    height: 100%;    position: absolute;    top: 0;    right: 0;    z-index: 2;}.main-timeline .timeline-icon{    width: 210px;    height: 210px;    border-radius: 50%;    border: 25px solid transparent;    border-top-color: #f44556;    border-right-color: #f44556;    margin: auto;    position: absolute;    top: 0;    left: 0;    bottom: 0;    right: 0;    z-index: 1;    transform: rotate(45deg);}.main-timeline .year{    display: block;    width: 110px;    height: 110px;    line-height: 110px;    border-radius: 50%;    background: #fff;    box-shadow: 0 0 20px rgba(0,0,0,0.4);    margin: auto;    font-size: 30px;    font-weight: bold;    color: #f44556;    text-align: center;    position: absolute;    top: 0;    left: 0;    bottom: 0;    right: 0;    transform: rotate(-45deg);}.main-timeline .timeline-content{    width: 35%;    float: right;    background: #f44556;    padding: 30px 20px;    margin: 50px 0;    z-index: 1;    position: relative;}.main-timeline .timeline-content:before{    content: "";    width: 20%;    height: 15px;    background: #f44556;    position: absolute;    top: 50%;    left: -20%;    z-index: -1;    transform: translateY(-50%);}.main-timeline .title{    font-size: 20px;    font-weight: bold;    color: #fff;    margin: 0 0 10px 0;}.main-timeline .description{    font-size: 16px;    color: #fff;    line-height: 24px;    margin: 0;}.main-timeline .timeline:nth-child(2n) .timeline-icon{ transform: rotate(-135deg); }.main-timeline .timeline:nth-child(2n) .year{ transform: rotate(135deg); }.main-timeline .timeline:nth-child(2n) .timeline-content{ float: left; }.main-timeline .timeline:nth-child(2n) .timeline-content:before{    left: auto;    right: -20%;}.main-timeline .timeline:nth-child(2n) .timeline-icon{    border-top-color: #e97e2e;    border-right-color: #e97e2e;}.main-timeline .timeline:nth-child(2n) .year{ color: #e97e2e; }.main-timeline .timeline:nth-child(2n) .timeline-content,.main-timeline .timeline:nth-child(2n) .timeline-content:before{ background: #e97e2e; }.main-timeline .timeline:nth-child(3n) .timeline-icon{    border-top-color: #13afae;    border-right-color: #13afae;}.main-timeline .timeline:nth-child(3n) .year{ color: #13afae; }.main-timeline .timeline:nth-child(3n) .timeline-content,.main-timeline .timeline:nth-child(3n) .timeline-content:before{ background: #13afae; }.main-timeline .timeline:nth-child(4n) .timeline-icon{    border-top-color: #105572;    border-right-color: #105572;}.main-timeline .timeline:nth-child(4n) .year{ color: #105572; }.main-timeline .timeline:nth-child(4n) .timeline-content,.main-timeline .timeline:nth-child(4n) .timeline-content:before{ background: #105572; }@media only screen and (max-width: 1199px){    .main-timeline .timeline{ margin-top: -103px; }    .main-timeline .timeline-content:before{ left: -18%; }    .main-timeline .timeline:nth-child(2n) .timeline-content:before{ right: -18%; }}@media only screen and (max-width: 990px){    .main-timeline .timeline{ margin-top: -127px; }    .main-timeline .timeline-content:before{ left: -2%; }    .main-timeline .timeline:nth-child(2n) .timeline-content:before{ right: -2%; }}@media only screen and (max-width: 767px){    .main-timeline .timeline{        margin-top: 0;        overflow: hidden;    }    .main-timeline .timeline:before,    .main-timeline .timeline:nth-child(2n):before{        box-shadow: none;    }    .main-timeline .timeline-icon,    .main-timeline .timeline:nth-child(2n) .timeline-icon{        margin-top: -30px;        margin-bottom: 20px;        position: relative;        transform: rotate(135deg);    }    .main-timeline .year,    .main-timeline .timeline:nth-child(2n) .year{ transform: rotate(-135deg); }    .main-timeline .timeline-content,    .main-timeline .timeline:nth-child(2n) .timeline-content{        width: 100%;        float: none;        border-radius: 0 0 20px 20px;        text-align: center;        padding: 25px 20px;        margin: 0 auto;    }    .main-timeline .timeline-content:before,    .main-timeline .timeline:nth-child(2n) .timeline-content:before{        width: 15px;        height: 25px;        position: absolute;        top: -22px;        left: 50%;        z-index: -1;        transform: translate(-50%,0);    }}

该CSS3代码中用了很多变形、角度等CSS3特性，不熟悉CSS3的同学可以参考CSS3手册。