

每日前端实战系列的全部源代码请从 github 下载:
https://github.com/comehope/front-end-daily-challenges
定义 dom,只有 1 个元素:
<p class="loader"></p>
居中显示:
body {
margin: 0;
height: 100vh;
display: flex;
align-items: center;
justify-content: center;
background: radial-gradient(darkgreen 30%, forestgreen);
}定义容器尺寸:
.loader {
width: 10em;
height: 10em;
font-size: 20px;
}用 box-shadow 画出 2 组点阵:
.loader::before,
.loader::after {
content: '';
position: absolute;
width: 1em;
height: 1em;
background-color: currentColor;
box-shadow:
0 0, 2em 0, 4em 0, 6em 0,
0 2em, 2em 2em, 4em 2em, 6em 2em,
0 4em, 2em 4em, 4em 4em, 6em 4em,
0 6em, 2em 6em, 4em 6em, 6em 6em;
border-radius: 50%;
}
.loader::before {
color: gold;
}
.loader::after {
color: dodgerblue;
}定义动画:
@keyframes round {
0% {
transform: translateX(0) translateY(0);
}
25% {
transform: translateX(3em) translateY(0);
}
50% {
transform: translateX(3em) translateY(3em);
}
75% {
transform: translateX(0) translateY(3em);
}
}最后,把动画效果应用到点阵上:
.loader::before,
.loader::after {
animation: round 2s ease infinite;
}
.loader::after {
animation-delay: -1s;
}大功告成!
