<section class="error-body">
  <video preload="auto" class="background" src="https://s3-us-west-2.amazonaws.com/s.cdpn.io/396624/err.mp4" autoplay muted loop></video>
  <div class="message">
    <h1 t="404">404</h1>
    <div class="bottom">
      <p>You have lost your way</p>
      <a href="#">return home</a>
    </div>
  </div>
</section>

$bg: #11111b;
$red: #ff6778;
$green: #afd33d;
$blue: #1122ff;
$text: $green;

@function font($to, $from, $toWidth, $fromWidth) {
    $slope: ($to - $from) / ($toWidth - $fromWidth);
    $base: $from - $slope * $fromWidth;
    @return calc(#{$base} + #{100vw * $slope});
}
@mixin dotgrid($dot: #aaa,$dot-background: #000,$dot-size: 1px,$dot-spacing: 22px) {
    background: linear-gradient(90deg, $dot-background ($dot-spacing - $dot-size), transparent 1%) center, linear-gradient($dot-background ($dot-spacing - $dot-size), transparent 1%) center, $dot;
    background-size: $dot-spacing $dot-spacing;
    background-position: center;
}

:root {
  box-sizing: border-box;
  cursor: default;
}
::selection {
  color: $bg;
  background-color: lighten($text, 10%);
}
html, body {
  width: 100%;
  height: 100%;
  background-color: $bg;
  color: $text;
  font-size: font(22px, 9px, 1920px, 320px);
}
.error-body {
  position: relative;
  width: 100%;
  height: 100%;
  overflow: hidden;
  &:before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: $text;
    mix-blend-mode: overlay;
    z-index:1;
  }
  &:after {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    @include dotgrid($dot: lighten($bg, 100%), $dot-background: $bg);
    opacity: .2;
    z-index:1;
  }
  .background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    filter: grayscale(1);
    mix-blend-mode: luminosity;
  }
  .message {
    position: relative;
    width: 100%;
    height: 100%;
    text-align: center;
    z-index:3;
    h1 {
      $faded: rgba($text, .3);
      position: absolute;
      top: 10%;
      left: 0%;
      width: 100%;
      font-size: 10em;
      margin: 0;
      animation: shake 600ms ease-in-out infinite alternate;
      text-shadow: 0 0 .07em $text,
               -.2em 0 2em $faded,
                .2em 0 2em $faded;
      user-select: none;
      &:before {
        content: attr(t);
        position: absolute;
        left: 50%;
        transform: translate(-50%, .34em);
        height: .1em;
        line-height: .5em;
        width: 100%;
        animation: scan 500ms ease-in-out infinite alternate random(600)+ms,
          glitch-anim 300ms ease-in-out infinite alternate;
        overflow: hidden;
        opacity: .7;
      }
      &:after {
        $n:random(30);
        content: attr(t);
        position: absolute;
        top: -$n+px;
        left: 50%;
        transform: translate(-50%, .34em);
        height: .5em;
        line-height: .1em;
        width: 100%;
        animation: scan 665ms ease-in-out infinite alternate random(600)+ms,
          glitch-anim 300ms ease-in-out infinite alternate;
        overflow: hidden;
        opacity: .8;
      }
    }
    .bottom {
      position: absolute;
      top: 65%;
      left: 0;
      width: 100%;
    }
    p, a {
      font-size: 2em;
      font-family: monospace;
      text-shadow: 0 0 5px $text;
      filter: blur(.8px);
    }
    a {
      $dd: 225ms;
      
      position: relative;
      color: $text;
      text-decoration: none;
      font-weight: 700;
      border: 2px solid $text;
      text-transform: uppercase;
      padding: 5px 30px;
      box-shadow: inset 0 0 0 0 rgba($text, .2);
      transition: 25ms ease-in-out all 0ms;
      overflow: hidden;
      animation: attn 3s ease-in-out infinite;
      &:hover {
        cursor: crosshair;
        box-shadow: inset 0 -2em 0 0 rgba($text, .2);
        transition: 225ms ease-in-out all $dd;
        animation: none;
        &:before,
        &:after {
          transform: translate(-50%, 0) scale(0, 1);
        }
      }
      &:active {
        box-shadow: inset 0 -2em 0 0 rgba($text, .5);
        transition: 225ms ease-in-out all $dd;
      }
      &:before,
      &:after {
        content: '';
        position: absolute;
        left: 50%;
        transform: translate(-50%, 0) scale(1, 1);
        transform-origin: center;
        background-color: $bg;
        width: 90%;
        height: 5px;
        transition: $dd ease-in-out all;
        mix-blend-mode: hard-light;
      }
      &:before {
        top: -4px;
      }
      &:after {
        bottom: -4px;
      }
    }
  }
}

@keyframes scan {
  $num: random(30);
  $numVal: $num * .01em;
  from , 20%, 100%{
    height: 0;    
    transform: translate(-50%, .44em);
  }
  10%,15% {
    height: 1em;
    line-height: .2em;
    transform: translate(-55%, $numVal);
  }
}
@keyframe pulse {
  $faded: rgba($text, .3);
  from {
    text-shadow: 0 0 0 $text,
                 0 0 0 $faded,
                 0 0 0 $faded;
  }
  to {
    text-shadow: 0 0 .07em $text,
               -.2em 0 2em $faded,
                .2em 0 2em $faded;
  }
}
@keyframes attn {
  0%, 100% {
    opacity: 1;
  }
  30%, 35% {
    opacity: .4;
  }
}
@keyframes shake {
  0%, 100% {
    transform: translate(-1px, 0);
  }
  10% {
    transform: translate(2px, 1px);
  }
  30% {
    transform: translate(-3px, 2px);
  }
  35% {
    transform: translate(2px, -3px);
    filter: blur(4px);
  }
  45% {
    transform: translate(2px, 2px) skewY(-8deg) scale( .96, 1);
    filter: blur(0);
  }
  50% {
    transform: translate(-3px, 1px);
  }
}
@keyframes glitch-anim {
  $steps: 10;
  @for $i from 0 through $steps {
    #{percentage($i*(1/$steps))} {
      clip: rect(random(100)+px, 9999px, random(100)+px, 0);
    }
  }
}