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/comehope/pen/QrxxaW
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/p/pEgDAM/cgRgQHr
源代码下载
请从 github 下载。
https://github.com/comehope/front-end-daily-challenges/tree/master/021-a-text-sliding-effect-ui
代码解读
定义 dom，容器中包含 question 和 answer：
<div>
<p>
<span class="question">Who gives you milk?</span>
<span class="answer">cow</span>
</p>
</div>居中显示：
html, body {
height: 100%;
display: flex;
align-items: center;
justify-content: center;
background: darkcyan;
}设置文本样式：
p {
width: 400px;
height: 2.5em;
color: gold;
font-size: 24px;
border: 2px solid gold;
line-height: 2.5em;
text-align: center;
border-radius: 10px;
font-family: sans-serif;
letter-spacing: 2px;
word-spacing: 2px;
box-shadow: 5px 5px 10px rgba(0, 0, 0, 0.2);
}设置答案的样式：
p {
position: relative;
}
p span {
position: absolute;
width: 100%;
top: 0;
left: 0;
}
p .answer {
color: whitesmoke;
font-size: 1.1em;
text-transform: uppercase;
background: rgba(0, 0, 0, 0.1);
}增加问题与答案滑动切换的动画效果：
p {
overflow: hidden;
}
p span {
transition: 0.5s ease-out;
}
p .question {
left: 0;
}
p:hover .question {
left: 100%;
}
p .answer {
left: -100%;
}
p:hover .answer {
left: 0;
}dom 中再增加 2 个问题：
<div>
<p>
<span class="question">Who gives you milk?</span>
<span class="answer">cow</span>
</p>
<p>
<span class="question">Who likes to eat flies?</span>
<span class="answer">frog</span>
</p>
<p>
<span class="question">Who have large claws?</span>
<span class="answer">crab</span>
</p>
</div>dom 中增加标题：
<div>
<h1>Who Am I</h1>
<p>
<span class="question">Who gives you milk?</span>
<span class="answer">cow</span>
</p>
<p>
<span class="question">Who likes to eat flies?</span>
<span class="answer">frog</span>
</p>
<p>
<span class="question">Who have large claws?</span>
<span class="answer">crab</span>
</p>
</div>设置标题样式：
h1 {
font-family: sans-serif;
color: gold;
text-align: center;
}最后，用伪元素增加大问号作为装饰背景：
h1 {
position: relative;
}
h1::after {
content: '?';
position: absolute;
top: -0.35em;
left: 0;
font-size: 25em;
transform: rotate(15deg);
color: cyan;
filter: opacity(0.3);
text-shadow: 10px 10px 10px rgba(0, 0, 0, 0.2);
}