Loading 效果 - 图1

    HTML

    <div class="spinner"></div>

    CSS

    `.spinner {
    width: 40px;
    height: 40px;
    background-color: #333;

    margin: 100px auto;
    -webkit-animation: sk-rotateplane 1.2s infinite ease-in-out;
    animation: sk-rotateplane 1.2s infinite ease-in-out;
    }

    @-webkit-keyframes sk-rotateplane {
    0% {-webkit-transform: perspective(120px) }
    50% {-webkit-transform: perspective(120px) rotateY(180deg) }
    100% {-webkit-transform: perspective(120px) rotateY(180deg) rotateX(180deg) }
    }

    @keyframes sk-rotateplane {
    0% {
    transform: perspective(120px) rotateX(0deg) rotateY(0deg);
    -webkit-transform: perspective(120px) rotateX(0deg) rotateY(0deg)
    } 50% {
    transform: perspective(120px) rotateX(-180.1deg) rotateY(0deg);
    -webkit-transform: perspective(120px) rotateX(-180.1deg) rotateY(0deg)
    } 100% {
    transform: perspective(120px) rotateX(-180deg) rotateY(-179.9deg);
    -webkit-transform: perspective(120px) rotateX(-180deg) rotateY(-179.9deg);
    }
    }
    `

    解析：定义一个 div 元素，设置边长为 40px 背景白色的正方形，然后设置循环翻转动画实现该加载效果动画

    perspective 属性定义 3D 元素距视图的距离

    Loading 效果 - 图2

    HTML

    `






    CSS

    `.sk-chase {
    width: 40px;
    height: 40px;
    position: relative;
    animation: sk-chase 2.5s infinite linear both;
    }

    .sk-chase-dot {
    width: 100%;
    height: 100%;
    position: absolute;
    left: 0;
    top: 0;
    animation: sk-chase-dot 2.0s infinite ease-in-out both;
    }

    .sk-chase-dot:before {
    content: ‘’;
    display: block;
    width: 25%;
    height: 25%;
    background-color: #fff;
    border-radius: 100%;
    animation: sk-chase-dot-before 2.0s infinite ease-in-out both;
    }

    .sk-chase-dot:nth-child(1) { animation-delay: -1.1s; }
    .sk-chase-dot:nth-child(2) { animation-delay: -1.0s; }
    .sk-chase-dot:nth-child(3) { animation-delay: -0.9s; }
    .sk-chase-dot:nth-child(4) { animation-delay: -0.8s; }
    .sk-chase-dot:nth-child(5) { animation-delay: -0.7s; }
    .sk-chase-dot:nth-child(6) { animation-delay: -0.6s; }
    .sk-chase-dot:nth-child(1):before { animation-delay: -1.1s; }
    .sk-chase-dot:nth-child(2):before { animation-delay: -1.0s; }
    .sk-chase-dot:nth-child(3):before { animation-delay: -0.9s; }
    .sk-chase-dot:nth-child(4):before { animation-delay: -0.8s; }
    .sk-chase-dot:nth-child(5):before { animation-delay: -0.7s; }
    .sk-chase-dot:nth-child(6):before { animation-delay: -0.6s; }

    @keyframes sk-chase {
    100% {transform: rotate(360deg); }
    }

    @keyframes sk-chase-dot {
    80%, 100% {transform: rotate(360deg); }
    }

    @keyframes sk-chase-dot-before {
    50% {
    transform: scale(0.4);
    } 100%, 0% {
    transform: scale(1.0);
    }
    }
    `

    解析：定义一个父元素 div，内含六个白色实心圆点，添加旋转动画，通过设置不同的延迟时间来达到依次出现的效果

    Loading 效果 - 图3

    HTML

    `


    CSS

    `.spinner {
    width: 40px;
    height: 40px;

    position: relative;
    margin: 100px auto;
    }

    .double-bounce1, .double-bounce2 {
    width: 100%;
    height: 100%;
    border-radius: 50%;
    background-color: #333;
    opacity: 0.6;
    position: absolute;
    top: 0;
    left: 0;

    -webkit-animation: sk-bounce 2.0s infinite ease-in-out;
    animation: sk-bounce 2.0s infinite ease-in-out;
    }

    .double-bounce2 {
    -webkit-animation-delay: -1.0s;
    animation-delay: -1.0s;
    }

    @-webkit-keyframes sk-bounce {
    0%, 100% {-webkit-transform: scale(0.0) }
    50% {-webkit-transform: scale(1.0) }
    }

    @keyframes sk-bounce {
    0%, 100% {
    transform: scale(0.0);
    -webkit-transform: scale(0.0);
    } 50% {
    transform: scale(1.0);
    -webkit-transform: scale(1.0);
    }
    }
    `

    解析：两个子元素 div 实现半透明的圆形，设置绝对定位重叠在一起，然后设置相同的动画通过不同的延迟时间交替放大缩小。

    Loading 效果 - 图4

    HTML

    `





    CSS

    `.spinner {
    margin: 100px auto;
    width: 50px;
    height: 40px;
    text-align: center;
    font-size: 10px;
    }

    .spinner > div {
    background-color: #333;
    height: 100%;
    width: 6px;
    display: inline-block;

    -webkit-animation: sk-stretchdelay 1.2s infinite ease-in-out;
    animation: sk-stretchdelay 1.2s infinite ease-in-out;
    }

    .spinner .rect2 {
    -webkit-animation-delay: -1.1s;
    animation-delay: -1.1s;
    }

    .spinner .rect3 {
    -webkit-animation-delay: -1.0s;
    animation-delay: -1.0s;
    }

    .spinner .rect4 {
    -webkit-animation-delay: -0.9s;
    animation-delay: -0.9s;
    }

    .spinner .rect5 {
    -webkit-animation-delay: -0.8s;
    animation-delay: -0.8s;
    }

    @-webkit-keyframes sk-stretchdelay {
    0%, 40%, 100% {-webkit-transform: scaleY(0.4) }
    20% {-webkit-transform: scaleY(1.0) }
    }

    @keyframes sk-stretchdelay {
    0%, 40%, 100% {
    transform: scaleY(0.4);
    -webkit-transform: scaleY(0.4);
    } 20% {
    transform: scaleY(1.0);
    -webkit-transform: scaleY(1.0);
    }
    }
    `

    解析：在类名为 spinner 元素下有五个 div 实现的长方形元素，设置 Y 轴的缩放，通过不同的延迟时间来达到依次变化的效果。

    Loading 效果 - 图5

    HTML

    `


    CSS

    `.cube1, .cube2 {
    background-color: #333;
    width: 15px;
    height: 15px;
    position: absolute;
    top: 0;
    left: 0;

    -webkit-animation: sk-cubemove 1.8s infinite ease-in-out;
    animation: sk-cubemove 1.8s infinite ease-in-out;
    }

    .cube2 {
    -webkit-animation-delay: -0.9s;
    animation-delay: -0.9s;
    }

    @-webkit-keyframes sk-cubemove {
    25% {-webkit-transform: translateX(42px) rotate(-90deg) scale(0.5) }
    50% {-webkit-transform: translateX(42px) translateY(42px) rotate(-180deg) }
    75% {-webkit-transform: translateX(0px) translateY(42px) rotate(-270deg) scale(0.5) }
    100% {-webkit-transform: rotate(-360deg) }
    }

    @keyframes sk-cubemove {
    25% {
    transform: translateX(42px) rotate(-90deg) scale(0.5);
    -webkit-transform: translateX(42px) rotate(-90deg) scale(0.5);
    } 50% {
    transform: translateX(42px) translateY(42px) rotate(-179deg);
    -webkit-transform: translateX(42px) translateY(42px) rotate(-179deg);
    } 50.1% {
    transform: translateX(42px) translateY(42px) rotate(-180deg);
    -webkit-transform: translateX(42px) translateY(42px) rotate(-180deg);
    } 75% {
    transform: translateX(0px) translateY(42px) rotate(-270deg) scale(0.5);
    -webkit-transform: translateX(0px) translateY(42px) rotate(-270deg) scale(0.5);
    } 100% {
    transform: rotate(-360deg);
    -webkit-transform: rotate(-360deg);
    }
    }
    `

    解析：两个子元素实现白色的方块，添加动画属性，在 X 轴和 Y 轴分别设置移动距离和缩放，通过不同的延迟时间来分离他们，rorate 实现围绕中心旋转。

    Loading 效果 - 图6

    HTML

    <div class="spinner"></div>

    CSS

    `.spinner {
    width: 40px;
    height: 40px;
    margin: 100px auto;
    background-color: #333;

    border-radius: 100%;
    -webkit-animation: sk-scaleout 1.0s infinite ease-in-out;
    animation: sk-scaleout 1.0s infinite ease-in-out;
    }

    @-webkit-keyframes sk-scaleout {
    0% {-webkit-transform: scale(0) }
    100% {
    -webkit-transform: scale(1.0);
    opacity: 0;
    }
    }

    @keyframes sk-scaleout {
    0% {
    -webkit-transform: scale(0);
    transform: scale(0);
    } 100% {
    -webkit-transform: scale(1.0);
    transform: scale(1.0);
    opacity: 0;
    }
    }
    `

    解析：唯一的 div 元素实现白色背景圆点，通过设置缩放和透明度实现呼吸灯的效果。

    Loading 效果 - 图7

    HTML

    `


    CSS

    `.spinner {
    margin: 100px auto;
    width: 40px;
    height: 40px;
    position: relative;
    text-align: center;

    -webkit-animation: sk-rotate 2.0s infinite linear;
    animation: sk-rotate 2.0s infinite linear;
    }

    .dot1, .dot2 {
    width: 60%;
    height: 60%;
    display: inline-block;
    position: absolute;
    top: 0;
    background-color: #333;
    border-radius: 100%;

    -webkit-animation: sk-bounce 2.0s infinite ease-in-out;
    animation: sk-bounce 2.0s infinite ease-in-out;
    }

    .dot2 {
    top: auto;
    bottom: 0;
    -webkit-animation-delay: -1.0s;
    animation-delay: -1.0s;
    }

    @-webkit-keyframes sk-rotate {100% { -webkit-transform: rotate(360deg) }}
    @keyframes sk-rotate {100% { transform: rotate(360deg); -webkit-transform: rotate(360deg) }}

    @-webkit-keyframes sk-bounce {
    0%, 100% {-webkit-transform: scale(0.0) }
    50% {-webkit-transform: scale(1.0) }
    }

    @keyframes sk-bounce {
    0%, 100% {
    transform: scale(0.0);
    -webkit-transform: scale(0.0);
    } 50% {
    transform: scale(1.0);
    -webkit-transform: scale(1.0);
    }
    }
    `

    解析：两个实心圆形围绕中心做循环的缩放旋转运动，因为不同的延迟时间来达到它们同一时间呈现相反的表现。

    Loading 效果 - 图8

    HTML

    `



    CSS

    `.spinner {
    margin: 100px auto 0;
    width: 70px;
    text-align: center;
    }

    .spinner > div {
    width: 18px;
    height: 18px;
    background-color: #333;

    border-radius: 100%;
    display: inline-block;
    -webkit-animation: sk-bouncedelay 1.4s infinite ease-in-out both;
    animation: sk-bouncedelay 1.4s infinite ease-in-out both;
    }

    .spinner .bounce1 {
    -webkit-animation-delay: -0.32s;
    animation-delay: -0.32s;
    }

    .spinner .bounce2 {
    -webkit-animation-delay: -0.16s;
    animation-delay: -0.16s;
    }

    @-webkit-keyframes sk-bouncedelay {
    0%, 80%, 100% {-webkit-transform: scale(0) }
    40% {-webkit-transform: scale(1.0) }
    }

    @keyframes sk-bouncedelay {
    0%, 80%, 100% {
    -webkit-transform: scale(0);
    transform: scale(0);
    } 40% {
    -webkit-transform: scale(1.0);
    transform: scale(1.0);
    }
    }
    `

    解析：三个实色圆形横向排列，线性动画 scale 从 0 到 1，通过给它们不同的延迟时间，呈现依次交替的效果。

    Loading 效果 - 图9

    HTML

    `












    CSS

    `.sk-circle {
    margin: 100px auto;
    width: 40px;
    height: 40px;
    position: relative;
    }
    .sk-circle .sk-child {
    width: 100%;
    height: 100%;
    position: absolute;
    left: 0;
    top: 0;
    }
    .sk-circle .sk-child:before {
    content: ‘’;
    display: block;
    margin: 0 auto;
    width: 15%;
    height: 15%;
    background-color: #333;
    border-radius: 100%;
    -webkit-animation: sk-circleBounceDelay 1.2s infinite ease-in-out both;
    animation: sk-circleBounceDelay 1.2s infinite ease-in-out both;
    }
    .sk-circle .sk-circle2 {
    -webkit-transform: rotate(30deg);
    -ms-transform: rotate(30deg);
    transform: rotate(30deg); }
    .sk-circle .sk-circle3 {
    -webkit-transform: rotate(60deg);
    -ms-transform: rotate(60deg);
    transform: rotate(60deg); }
    .sk-circle .sk-circle4 {
    -webkit-transform: rotate(90deg);
    -ms-transform: rotate(90deg);
    transform: rotate(90deg); }
    .sk-circle .sk-circle5 {
    -webkit-transform: rotate(120deg);
    -ms-transform: rotate(120deg);
    transform: rotate(120deg); }
    .sk-circle .sk-circle6 {
    -webkit-transform: rotate(150deg);
    -ms-transform: rotate(150deg);
    transform: rotate(150deg); }
    .sk-circle .sk-circle7 {
    -webkit-transform: rotate(180deg);
    -ms-transform: rotate(180deg);
    transform: rotate(180deg); }
    .sk-circle .sk-circle8 {
    -webkit-transform: rotate(210deg);
    -ms-transform: rotate(210deg);
    transform: rotate(210deg); }
    .sk-circle .sk-circle9 {
    -webkit-transform: rotate(240deg);
    -ms-transform: rotate(240deg);
    transform: rotate(240deg); }
    .sk-circle .sk-circle10 {
    -webkit-transform: rotate(270deg);
    -ms-transform: rotate(270deg);
    transform: rotate(270deg); }
    .sk-circle .sk-circle11 {
    -webkit-transform: rotate(300deg);
    -ms-transform: rotate(300deg);
    transform: rotate(300deg); }
    .sk-circle .sk-circle12 {
    -webkit-transform: rotate(330deg);
    -ms-transform: rotate(330deg);
    transform: rotate(330deg); }
    .sk-circle .sk-circle2:before {
    -webkit-animation-delay: -1.1s;
    animation-delay: -1.1s; }
    .sk-circle .sk-circle3:before {
    -webkit-animation-delay: -1s;
    animation-delay: -1s; }
    .sk-circle .sk-circle4:before {
    -webkit-animation-delay: -0.9s;
    animation-delay: -0.9s; }
    .sk-circle .sk-circle5:before {
    -webkit-animation-delay: -0.8s;
    animation-delay: -0.8s; }
    .sk-circle .sk-circle6:before {
    -webkit-animation-delay: -0.7s;
    animation-delay: -0.7s; }
    .sk-circle .sk-circle7:before {
    -webkit-animation-delay: -0.6s;
    animation-delay: -0.6s; }
    .sk-circle .sk-circle8:before {
    -webkit-animation-delay: -0.5s;
    animation-delay: -0.5s; }
    .sk-circle .sk-circle9:before {
    -webkit-animation-delay: -0.4s;
    animation-delay: -0.4s; }
    .sk-circle .sk-circle10:before {
    -webkit-animation-delay: -0.3s;
    animation-delay: -0.3s; }
    .sk-circle .sk-circle11:before {
    -webkit-animation-delay: -0.2s;
    animation-delay: -0.2s; }
    .sk-circle .sk-circle12:before {
    -webkit-animation-delay: -0.1s;
    animation-delay: -0.1s; }

    @-webkit-keyframes sk-circleBounceDelay {
    0%, 80%, 100% {
    -webkit-transform: scale(0);
    transform: scale(0);
    } 40% {
    -webkit-transform: scale(1);
    transform: scale(1);
    }
    }

    @keyframes sk-circleBounceDelay {
    0%, 80%, 100% {
    -webkit-transform: scale(0);
    transform: scale(0);
    } 40% {
    -webkit-transform: scale(1);
    transform: scale(1);
    }
    }
    `

    解析：整个加载效果由 12 个圆心组成，设置不同的旋转让它们呈现圆形环绕，然后设置不同的延迟时间，让它们做缩放运动。

    Loading 效果 - 图10

    HTML

    `









    CSS

    `.sk-cube-grid {
    width: 40px;
    height: 40px;
    margin: 100px auto;
    }

    .sk-cube-grid .sk-cube {
    width: 33%;
    height: 33%;
    background-color: #333;
    float: left;
    -webkit-animation: sk-cubeGridScaleDelay 1.3s infinite ease-in-out;
    animation: sk-cubeGridScaleDelay 1.3s infinite ease-in-out;
    }
    .sk-cube-grid .sk-cube1 {
    -webkit-animation-delay: 0.2s;
    animation-delay: 0.2s; }
    .sk-cube-grid .sk-cube2 {
    -webkit-animation-delay: 0.3s;
    animation-delay: 0.3s; }
    .sk-cube-grid .sk-cube3 {
    -webkit-animation-delay: 0.4s;
    animation-delay: 0.4s; }
    .sk-cube-grid .sk-cube4 {
    -webkit-animation-delay: 0.1s;
    animation-delay: 0.1s; }
    .sk-cube-grid .sk-cube5 {
    -webkit-animation-delay: 0.2s;
    animation-delay: 0.2s; }
    .sk-cube-grid .sk-cube6 {
    -webkit-animation-delay: 0.3s;
    animation-delay: 0.3s; }
    .sk-cube-grid .sk-cube7 {
    -webkit-animation-delay: 0s;
    animation-delay: 0s; }
    .sk-cube-grid .sk-cube8 {
    -webkit-animation-delay: 0.1s;
    animation-delay: 0.1s; }
    .sk-cube-grid .sk-cube9 {
    -webkit-animation-delay: 0.2s;
    animation-delay: 0.2s; }

    @-webkit-keyframes sk-cubeGridScaleDelay {
    0%, 70%, 100% {
    -webkit-transform: scale3D(1, 1, 1);
    transform: scale3D(1, 1, 1);
    } 35% {
    -webkit-transform: scale3D(0, 0, 1);
    transform: scale3D(0, 0, 1);
    }
    }

    @keyframes sk-cubeGridScaleDelay {
    0%, 70%, 100% {
    -webkit-transform: scale3D(1, 1, 1);
    transform: scale3D(1, 1, 1);
    } 35% {
    -webkit-transform: scale3D(0, 0, 1);
    transform: scale3D(0, 0, 1);
    }
    }
    `

    解析：九个方块通过 grid 布局，形成横向纵向分别三块，设置不同的延迟时间让它们做线性 3D 缩放运动。

    Loading 效果 - 图11

    HTML

    `












    CSS

    `.sk-fading-circle {
    margin: 100px auto;
    width: 40px;
    height: 40px;
    position: relative;
    }

    .sk-fading-circle .sk-circle {
    width: 100%;
    height: 100%;
    position: absolute;
    left: 0;
    top: 0;
    }

    .sk-fading-circle .sk-circle:before {
    content: ‘’;
    display: block;
    margin: 0 auto;
    width: 15%;
    height: 15%;
    background-color: #333;
    border-radius: 100%;
    -webkit-animation: sk-circleFadeDelay 1.2s infinite ease-in-out both;
    animation: sk-circleFadeDelay 1.2s infinite ease-in-out both;
    }
    .sk-fading-circle .sk-circle2 {
    -webkit-transform: rotate(30deg);
    -ms-transform: rotate(30deg);
    transform: rotate(30deg);
    }
    .sk-fading-circle .sk-circle3 {
    -webkit-transform: rotate(60deg);
    -ms-transform: rotate(60deg);
    transform: rotate(60deg);
    }
    .sk-fading-circle .sk-circle4 {
    -webkit-transform: rotate(90deg);
    -ms-transform: rotate(90deg);
    transform: rotate(90deg);
    }
    .sk-fading-circle .sk-circle5 {
    -webkit-transform: rotate(120deg);
    -ms-transform: rotate(120deg);
    transform: rotate(120deg);
    }
    .sk-fading-circle .sk-circle6 {
    -webkit-transform: rotate(150deg);
    -ms-transform: rotate(150deg);
    transform: rotate(150deg);
    }
    .sk-fading-circle .sk-circle7 {
    -webkit-transform: rotate(180deg);
    -ms-transform: rotate(180deg);
    transform: rotate(180deg);
    }
    .sk-fading-circle .sk-circle8 {
    -webkit-transform: rotate(210deg);
    -ms-transform: rotate(210deg);
    transform: rotate(210deg);
    }
    .sk-fading-circle .sk-circle9 {
    -webkit-transform: rotate(240deg);
    -ms-transform: rotate(240deg);
    transform: rotate(240deg);
    }
    .sk-fading-circle .sk-circle10 {
    -webkit-transform: rotate(270deg);
    -ms-transform: rotate(270deg);
    transform: rotate(270deg);
    }
    .sk-fading-circle .sk-circle11 {
    -webkit-transform: rotate(300deg);
    -ms-transform: rotate(300deg);
    transform: rotate(300deg);
    }
    .sk-fading-circle .sk-circle12 {
    -webkit-transform: rotate(330deg);
    -ms-transform: rotate(330deg);
    transform: rotate(330deg);
    }
    .sk-fading-circle .sk-circle2:before {
    -webkit-animation-delay: -1.1s;
    animation-delay: -1.1s;
    }
    .sk-fading-circle .sk-circle3:before {
    -webkit-animation-delay: -1s;
    animation-delay: -1s;
    }
    .sk-fading-circle .sk-circle4:before {
    -webkit-animation-delay: -0.9s;
    animation-delay: -0.9s;
    }
    .sk-fading-circle .sk-circle5:before {
    -webkit-animation-delay: -0.8s;
    animation-delay: -0.8s;
    }
    .sk-fading-circle .sk-circle6:before {
    -webkit-animation-delay: -0.7s;
    animation-delay: -0.7s;
    }
    .sk-fading-circle .sk-circle7:before {
    -webkit-animation-delay: -0.6s;
    animation-delay: -0.6s;
    }
    .sk-fading-circle .sk-circle8:before {
    -webkit-animation-delay: -0.5s;
    animation-delay: -0.5s;
    }
    .sk-fading-circle .sk-circle9:before {
    -webkit-animation-delay: -0.4s;
    animation-delay: -0.4s;
    }
    .sk-fading-circle .sk-circle10:before {
    -webkit-animation-delay: -0.3s;
    animation-delay: -0.3s;
    }
    .sk-fading-circle .sk-circle11:before {
    -webkit-animation-delay: -0.2s;
    animation-delay: -0.2s;
    }
    .sk-fading-circle .sk-circle12:before {
    -webkit-animation-delay: -0.1s;
    animation-delay: -0.1s;
    }

    @-webkit-keyframes sk-circleFadeDelay {
    0%, 39%, 100% {opacity: 0;}
    40% {opacity: 1;}
    }

    @keyframes sk-circleFadeDelay {
    0%, 39%, 100% {opacity: 0;}
    40% {opacity: 1;}
    }
    `

    解析：加载动画由 12 个实色圆点 360 度依次摆开，依次做旋转和透明度的改变。

    Loading 效果 - 图12

    HTML

    `




    CSS

    `.sk-folding-cube {
    margin: 20px auto;
    width: 40px;
    height: 40px;
    position: relative;
    -webkit-transform: rotateZ(45deg);
    transform: rotateZ(45deg);
    }

    .sk-folding-cube .sk-cube {
    float: left;
    width: 50%;
    height: 50%;
    position: relative;
    -webkit-transform: scale(1.1);
    -ms-transform: scale(1.1);
    transform: scale(1.1);
    }
    .sk-folding-cube .sk-cube:before {
    content: ‘’;
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: #333;
    -webkit-animation: sk-foldCubeAngle 2.4s infinite linear both;
    animation: sk-foldCubeAngle 2.4s infinite linear both;
    -webkit-transform-origin: 100% 100%;
    -ms-transform-origin: 100% 100%;
    transform-origin: 100% 100%;
    }
    .sk-folding-cube .sk-cube2 {
    -webkit-transform: scale(1.1) rotateZ(90deg);
    transform: scale(1.1) rotateZ(90deg);
    }
    .sk-folding-cube .sk-cube3 {
    -webkit-transform: scale(1.1) rotateZ(180deg);
    transform: scale(1.1) rotateZ(180deg);
    }
    .sk-folding-cube .sk-cube4 {
    -webkit-transform: scale(1.1) rotateZ(270deg);
    transform: scale(1.1) rotateZ(270deg);
    }
    .sk-folding-cube .sk-cube2:before {
    -webkit-animation-delay: 0.3s;
    animation-delay: 0.3s;
    }
    .sk-folding-cube .sk-cube3:before {
    -webkit-animation-delay: 0.6s;
    animation-delay: 0.6s;
    }
    .sk-folding-cube .sk-cube4:before {
    -webkit-animation-delay: 0.9s;
    animation-delay: 0.9s;
    }
    @-webkit-keyframes sk-foldCubeAngle {
    0%, 10% {
    -webkit-transform: perspective(140px) rotateX(-180deg);
    transform: perspective(140px) rotateX(-180deg);
    opacity: 0;
    } 25%, 75% {
    -webkit-transform: perspective(140px) rotateX(0deg);
    transform: perspective(140px) rotateX(0deg);
    opacity: 1;
    } 90%, 100% {
    -webkit-transform: perspective(140px) rotateY(180deg);
    transform: perspective(140px) rotateY(180deg);
    opacity: 0;
    }
    }

    @keyframes sk-foldCubeAngle {
    0%, 10% {
    -webkit-transform: perspective(140px) rotateX(-180deg);
    transform: perspective(140px) rotateX(-180deg);
    opacity: 0;
    } 25%, 75% {
    -webkit-transform: perspective(140px) rotateX(0deg);
    transform: perspective(140px) rotateX(0deg);
    opacity: 1;
    } 90%, 100% {
    -webkit-transform: perspective(140px) rotateY(180deg);
    transform: perspective(140px) rotateY(180deg);
    opacity: 0;
    }
    }
    `

    解析：四个等边方块形成一个正方形，整个旋转 45 度，然后每个方块通过不同的延迟时间，沿 X 轴做翻转动画。设置perspective是为了有 3D 的效果。

    结论：以上的这些案例原理都是通过不同的延迟时间，给元素或子元素设置包括 X、Y 和 Z 轴上的移动旋转，以及缩放来达到动画的效果。有了这些参考，加上创意还能做出更多的类型加载效果。