如何用纯 CSS 创作一个冒着热气的咖啡杯

特效实现

浏览数:897

2018-11-20

效果预览

在线演示

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

可交互视频教程

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请用 chrome, safari, edge 打开观看。

https://scrimba.com/c/cBm4eU9

源代码下载

本地下载

请从 github 下载。

https://github.com/comehope/front-end-daily-challenges/tree/master/013-hot-coffee-cup

代码解读

定义 dom,一个名为 coffee 的容器,其中包含一个名为 cup 的元素:

<div class="coffee">
    <div class="cup"></div>
</div>

居中显示:

html, body {
    height: 100%;
    align-items: center;
    justify-content: center;
    background-color: brown;
}

画出杯子主体:

.coffee .cup {
    width: 10em;
    height: 9em;
    background-color: white;
    border-bottom-left-radius: 1.5em;
    border-bottom-right-radius: 1.5em;
}

用伪元素画出杯口:

.coffee .cup {
    position: relative;
}

.coffee .cup::before {
    content: '';
    position: absolute;
    width: 100%;
    height: 2em;
    background-color: chocolate;
    border: 0.5em solid white;
    box-sizing: border-box;
    border-radius: 50%;
    top: -1em;
    box-shadow: inset 0 0 1em rgba(0, 0, 0, 0.5);
}

用伪元素画出杯子把手:

.coffee .cup::after {
    content: '';
    position: absolute;
    width: 3em;
    height: 3.5em;
    border: 0.8em solid white;
    border-radius: 50%;
    top: 20%;
    left: 80%;
}

dom 元素增加托盘:

<div class="coffee">
    <div class="cup"></div>
    <div class="plate"></div>
</div>

画出托盘:

.coffee {
    display: flex;
    flex-direction: column;
    align-items: center;
    height: calc(9em + 1em);
    position: relative;
}

.coffee .plate {
    width: 16em;
    height: 1em;
    background-color: white;
    border-bottom-left-radius: 50%;
    border-bottom-right-radius: 50%;
    position: absolute;
    bottom: -1px;
}

dom 元素增加杯中冒出的热气:

<div class="coffee">
    <div class="vapor">
        <span></span>
        <span></span>
        <span></span>
        <span></span>
        <span></span>
    </div>
    <div class="cup"></div>
    <div class="plate"></div>
</div>

画出杯中冒出的热气:

.coffee {
    height: calc(9em + 1em + 2em);
}

.coffee .vapor {
    width: 7em;
    display: flex;
    justify-content: space-between;
}

.coffee .vapor span {
    width: 0.1em;
    min-width: 1px;
    height: 2em;
    background-color: white;
}

定义热气冒出的动画:

.coffee .vapor span {
    animation: evaporation 2s linear infinite;
    filter: opacity(0);
}

@keyframes evaporation {
    from {
        transform: translateY(0);
        filter: opacity(1) blur(0.2em);
    }

    to {
        transform: translateY(-4em);
        filter: opacity(0) blur(0.4em);
    }
}

最后,调整每条热气的延迟时间,使动感更强:

.coffee .vapor span:nth-child(1) {
    animation-delay: 0.5s;
}

.coffee .vapor span:nth-child(2) {
    animation-delay: 0.1s;
}

.coffee .vapor span:nth-child(3) {
    animation-delay: 0.3s;
}

.coffee .vapor span:nth-child(4) {
    animation-delay: 0.4s;
}

.coffee .vapor span:nth-child(5) {
    animation-delay: 0.2s;
}

大功告成!

知识点

原文地址:https://segmentfault.com/a/1190000014734039