代码片段

产生随机颜色

function randomVal(val) {
    return Math.floor(Math.random() * (val + 1));
}
   
function randomColor() {
    return `rgb(${randomVal(255}, ${randomVal(255}, ${randomVal(255})`;
}

渐变色按钮（边框+文字）

<button class="btn">
    <span>渐变按钮</span>
</button>

.btn {
    padding: 1px;
    color: #4cdbbc;
    text-align: center;
    white-space: nowrap;
    cursor: pointer;
    outline: none;
    border: none;
    background: -webkit-linear-gradient(left, #fff 0%, #fff 100%), linear-gradient(90deg, #47d998 0%, #01d5d8 100%);
    background-clip: content-box, padding-box;
}
.btn span {
     background: linear-gradient(90deg, #47d998 0%, #01d5d8 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

向右的箭头（>）

.icon-v-right {
    width: 10px;
    height: 10px;
    border: 1px solid #dbdbdb;
    border-width: 1px 1px 0 0;
    transform: rotate(45deg);
}

translate居中

.center {
  position: absolute;
  top: 50%; /* 父元素高度的一半位置 */
  left: 50%; /* 父元素宽度的一半位置 */
  transform: translate(-50%, -50%); /* 元素本身的一半宽、高 */
}

请使用 animation 实现 loading 效果

/* 四分之一边框 loading */
<div class="loading"></div>
.loading {
    width: 100px;
    height: 100px;
    margin: 60px auto;
    position: relative;
    border: 10px solid rgba(0, 0, 0, 0.2);
    border-top-color: #000;
    border-radius: 50%;
    animation: rotateLoading 1.1s linear infinite;
}
@keyframes rotateLoading {
    from {
        transform: rotate(0deg);
    }
    100% {
        transform: rotate(360deg);
    }
}

/* 柱子 loading */
 <div class="pillar-loading">
    <span class="pillar"></span>
    <span class="pillar"></span>
    <span class="pillar"></span>
    <span class="pillar"></span>
    <span class="pillar"></span>
</div>
.pillar-loading {
    width: 60px;
    display: flex;
    justify-content: space-between;
    margin: 100px auto;
}
.pillar-loading .pillar {
    width: 8px;
    height: 40px;
    border-radius: 4px;
    background: lightgreen;
    animation: pillarLoading 1s ease infinite;
}
.pillar-loading .pillar:nth-child(2) {
    animation-delay: 0.2s;
}
.pillar-loading .pillar:nth-child(3) {
    animation-delay: 0.4s;
}
.pillar-loading .pillar:nth-child(4) {
    animation-delay: 0.6s;
}
.pillar-loading .pillar:nth-child(5) {
    animation-delay: 0.8s;
}
@keyframes pillarLoading {
    0%,
    100% {
        background: lightgreen;
    }
    50% {
        transform: scaleY(1.75);
        background: lightblue;
    }
}

 /* 圆点 loading */
 <div class="point-loading">
    <span class="point"></span>
    <span class="point"></span>
    <span class="point"></span>
    <span class="point"></span>
    <span class="point"></span>
    <span class="point"></span>
    <span class="point"></span>
    <span class="point"></span>
</div>
.point-loading {
    width: 100px;
    height: 100px;
    position: relative;
    margin: 100px auto 0;
}
.point-loading .point {
    position: absolute;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: lightgreen;
    animation: pointLoading 1s infinite;
}
.point-loading .point:nth-child(1) {
    left: 0;
    top: 50%;
    margin-top: -10px;
    animation-delay: 0.13s;
}
.point-loading .point:nth-child(2) {
    left: 14px;
    top: 14px;
    animation-delay: 0.26s;
}
.point-loading .point:nth-child(3) {
    left: 50%;
    top: 0;
    margin-left: -10px;
    animation-delay: 0.39s;
}
.point-loading .point:nth-child(4) {
    top: 14px;
    right: 14px;
    animation-delay: 0.52s;
}
.point-loading .point:nth-child(5) {
    right: 0;
    top: 50%;
    margin-top: -10px;
    animation-delay: 0.65s;
}
.point-loading .point:nth-child(6) {
    right: 14px;
    bottom: 14px;
    animation-delay: 0.78s;
}
.point-loading .point:nth-child(7) {
    bottom: 0;
    left: 50%;
    margin-left: -10px;
    animation-delay: 0.91s;
}
.point-loading .point:nth-child(8) {
    bottom: 14px;
    left: 14px;
    animation-delay: 1.04s;
}
@keyframes pointLoading {
    0% {
        transform: scale(1);
        opacity: 1;
    }
    100% {
        transform: scale(.3);
        opacity: 0.5;
    }
}

白色半透明遮罩层

.mask {
    height: 100px;
    background-image: linear-gradient(0deg, rgba(255,255,255,1) 50%, rgba(255,255,255,.3));
}

Android手机上小圆点变形

当单位为rem时，使用border-radius: 50%;，安卓手机上小圆点变形。

.dot {
   width: .1rem;
   height: .1rem;
   background: red;
   border-radius: 50%;
}

解决方法：将小圆点的width和height放大一倍，使用transform scale(.5)缩小一倍，再用transform-origin调整下小圆点的位置。

.dot {
   width: .2rem;
   height: .2rem;
   background: red;
   border-radius: 50%;
   transform scale(.5);
   transform-origin: 0% center;
}

[参考文章]:
rem单位border-radius:50%在安卓手机中画圆变形