效果预览

按下右侧的“点击预览”按钮可以在当前页面预览，点击链接可以全屏预览。

https://codepen.io/zhang-ou/pen/XqzGLp

可交互视频教程

此视频是可以交互的，你可以随时暂停视频，编辑视频中的代码。

请用 chrome, safari, edge 打开观看。

https://scrimba.com/c/cJdEgc9

源代码下载

请从 github 下载。

https://github.com/comehope/front-end-daily-challenges/tree/master/015-development-skills-card

代码解读

定义 dom，最外层的容器是卡片，内含一个标题，和一个技能说明，分别描述技能的名称和级别：

<div class="card">
    <h2>Development Skills</h2>
    <p class="skill html">
        <span>HTML5</span>
        <span class="level">90%</span>
    </p>
</div>

居中显示：

html, body {
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(dimgray, silver, silver, dimgray);
}

技能卡片布局：

.card {
    width: 400px;
    background: linear-gradient(#333, dimgray);
    box-sizing: border-box;
    padding: 20px;
    font-family: sans-serif;
    color: white;
    letter-spacing: 0.1em;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5);
}

文字布局：

.card h2 {
    text-transform: uppercase;
    text-align: center;
}

.card .skill {
    height: 50px;
}

.card .skill span {
    display: block;
}

.card .skill .level {
    transform: translateY(-1em);
    text-align: right;
}

用伪元素画出条形图：

.card .skill .level {
    position: relative;
}

.card .skill .level::before,
.card .skill .level::after {
    content: '';
    position: absolute;
    top: 1.2em;
    left: 0;
    width: 100%;
    height: 100%;
}

.card .skill .level::before {
    border: 1px solid mediumspringgreen;
    border-radius: 0.2em;
    height: 105%;
}

.card .skill .level::after {
    background-image: linear-gradient(to right, mediumspringgreen, mediumspringgreen);
    background-repeat: no-repeat;
    background-position: top 0.1em left 0.1em;
}

设置条形图的填充比例：

.card .skill.html .level::after {
    background-size: 90% 1em;
}

dom 增加多个技能，每个技能用命名不同的样式类：

<div class="card">
    <h2>Development Skills</h2>
    <p class="skill html">
        <span>HTML</span>
        <span class="level">90%</span>
    </p>
    <p class="skill css">
        <span>CSS</span>
        <span class="level">95%</span>
    </p>
    <p class="skill javascript">
        <span>JavaScript</span>
        <span class="level">80%</span>
    </p>
    <p class="skill svg">
        <span>SVG</span>
        <span class="level">60%</span>
    </p>
    <p class="skill canvas">
        <span>Canvas</span>
        <span class="level">75%</span>
    </p>
</div>

分别定义每个技能的条形图宽度：

.card .skill.css .level::after {
    background-size: 95% 1em;
}

.card .skill.javascript .level::after {
    background-size: 80% 1em;
}

.card .skill.svg .level::after {
    background-size: 60% 1em;
}

.card .skill.canvas .level::after {
    background-size: 75% 1em;
}

最后，增加一点交互效果：

.card .skill:hover {
    background-color: #333;
}

大功告成！

知识点

• linear-gradient() https://developer.mozilla.org/en-US/docs/Web/CSS/linear-gradient
• translateY() https://developer.mozilla.org/en-US/docs/Web/CSS/transform-function/translateY
• background-image https://developer.mozilla.org/en-US/docs/Web/CSS/background-image
• background-repeat https://developer.mozilla.org/en-US/docs/Web/CSS/background-repeat
• background-position https://developer.mozilla.org/en-US/docs/Web/CSS/background-position
• background-size https://developer.mozilla.org/en-US/docs/Web/CSS/background-size