Евгений Галиев

HTML

<div class="lines">
  <div class="line"></div>
  <div class="line"></div>
  <div class="line"></div>
</div>

Sass

*
  margin: 0
  padding: 0
  box-sizing: border-box !important

html, body
  height: 100%

body
  display: table
  width: 100%
  height: 100%
  background-color: #171717
  color: #000
  line-height: 1.6
  position: relative
  font-family: sans-serif
  overflow: hidden

.lines
  position: absolute
  top: 0
  left: 0
  right: 0
  height: 100%
  margin: auto
  width: 90vw

.line
  position: absolute
  width: 1px
  height: 100%
  top: 0
  left: 50%
  background: rgba(255, 255, 255, 0.1)
  overflow: hidden

  &::after
    content: ''
    display: block
    position: absolute
    height: 15vh
    width: 100%
    top: -50%
    left: 0
    background: linear-gradient(to bottom, rgba(255, 255, 255, 0) 0%, #ffffff 75%, #ffffff 100%)
    animation: drop 7s 0s infinite
    animation-fill-mode: forwards
    animation-timing-function: cubic-bezier(0.4, 0.26, 0, 0.97)

  &:nth-child(1)
    margin-left: -25%
    &::after
      animation-delay: 2s

  &:nth-child(3)
    margin-left: 25%
    &::after
      animation-delay: 2.5s

@keyframes drop
  0%
    top: -50%
  100%
    top: 110%

Или CSS

/* Анимация в обложке */
.ez-anima-lines-block {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 100%;
    margin: auto;
    width: 90vw;
    z-index: -1;
}
.ez-anima-line {
    position: absolute;
    width: 1px;
    height: 100%;
    top: 0;
    left: 50%;
    background: rgba(255, 255, 255, 0.1);
    overflow: hidden;
}
.ez-anima-line::after {
    content: '';
    display: block;
    position: absolute;
    height: 15vh;
    width: 100%;
    top: -50%;
    left: 0;
    background: linear-gradient(to bottom, rgba(255, 255, 255, 0) 0%, #ffffff 75%, #ffffff 100%);
    animation: ezdrop 7s 0s infinite;
    animation-fill-mode: forwards;
    animation-timing-function: cubic-bezier(0.4, 0.26, 0, 0.97);
}
.ez-anima-line:nth-child(1) {
    margin-left: -25%;
}
.ez-anima-line:nth-child(1)::after {
    animation-delay: 2s;
}
.ez-anima-line:nth-child(3) {
    margin-left: 25%;
}
.ez-anima-line:nth-child(3)::after {
    animation-delay: 2.5s;
}
@keyframes ezdrop {
    0% {top: -50%;}
    100% {top: 110%;}
}