Websites/webkit.org/demos/intersection-observer/triggered-animation/style.css

body {
    background-color: rgba(239, 175, 82, 1);
    font-family: Helvetica;
    color: rgba(230, 131, 99, 1);
}

p {
    color: rgba(54, 115, 171, 1);
}

.animation-container h1 {
    font-variant: small-caps;
    margin-top: 0.2em;
    font-size: 34pt;
    font-weight: bold;
    text-align: center;
}

.animation-container {
    position: relative;
    overflow: hidden;
    height: 400px;
    width: calc(100% - 100px);
    margin: 1200px 50px;
    padding: 20px;
    box-sizing: border-box;
    background-color: rgba(54, 115, 171, 1);
    border: 10px solid rgba(94, 189, 186, 1);
    border-radius: 20px;
}

.animation-container .box {
    position: relative;
    width: 200px;
    height: 200px;
    background-color: rgba(219, 89, 54, 1);
    border-radius: 10px;
}

.slide.box {
    display: inline-block;
    transform: translateX(2000px);
}

.animation-container.visible > .slide.box {
    transform: translateX(20px);
    transition: transform 2s;
}

.slide.animation-container div:nth-of-type(1) {
    transition-delay: 1s !important;
}
.slide.animation-container div:nth-of-type(2) {
    transition-delay: 1.4s !important;;
}
.slide.animation-container div:nth-of-type(3) {
    transition-delay: 1.8s !important;;
}

.spin {
    margin: 50px calc((100% - 200px) / 2);
}

.animation-container.visible .spin {
    animation: spin 3s 1s 10;
}

@keyframes spin {
    from { transform: rotate(0); }
    to   { transform: rotate(360deg); }
}

.animation-container.svg {
    height: 650px;
}

.animation-container.svg path {
    stroke-width: 8px;
    fill: none;
    stroke: #f9727f;
    stroke-dasharray: 80px;
    stroke-linecap: round;
}

.animation-container.svg.visible {
    animation-name: stroke-move;
    animation-duration: 6s;
    animation-delay: 1s;
    animation-timing-function: ease-in-out;
    animation-iteration-count: infinite;
    animation-direction: alternate;
}

@keyframes stroke-move {
  from {
      stroke-dashoffset: 0;
  }
  to {
      stroke-dashoffset: 500px;
  }
}

.animation-container.svg circle {
    fill: #c26c84;
    stroke-width: 12px;
    stroke: #fab193;
    r: 50px;
}

.animation-container.svg.visible circle {
    animation-name: circle-scale;
    animation-duration: 1.5s;
    animation-delay: 2s;
    animation-timing-function: ease-in-out;
    animation-iteration-count: infinite;
    animation-direction: alternate;
}

.animation-container.svg circle:nth-of-type(2) {
    animation-duration: 1.7s;
}

.animation-container.svg circle:nth-of-type(3) {
    animation-duration: 1.2s;
}

.animation-container.svg circle:nth-of-type(4) {
    animation-duration: 2.1s;
}

.animation-container.svg circle:nth-of-type(5) {
    animation-duration: 1.6s;
}

@keyframes circle-scale {
  from {
      stroke-width: 12px;
      fill-opacity: 1;
      r: 50px;
  }
  to {
      stroke-width: 2px;
      fill-opacity: 0.3;
      r: 80px;
  }
}