あまり知られていない！ CSSを使用してオーロラ効果を作成する

<p class="g-wrap">
</p>

@function randomNum($max, $min: 0, $u: 1) {
 @return ($min + random($max)) * $u;
}

@function shadowSet($n, $size) {
    $shadow : 0 0 0 0 #fff;
    
    @for $i from 0 through $n { 
        $x: randomNum(350);
        $y: randomNum(500);
        $scale: randomNum($size) / 10;
        
        $shadow: $shadow, #{$x}px #{$y}px 0 #{$scale}px rgba(255, 255, 255, .8);
    }
    
    @return $shadow;
}

.g-wrap {
    position: relative;
    width: 350px;
    height: 500px;
    background: #0b1a3a;
    overflow: hidden;
    
    &::before {
        content: "";
        position: absolute;
        width: 1px;
        height: 1px;
        border-radius: 50%;
        box-shadow: shadowSet(100, 6);
}

<p class="g-wrap">
  <p class="g-aurora"></p>
</p>

.g-aurora {
    width: 400px;
    height: 300px;
    background: radial-gradient(
        circle at 100% 100%,
        transparent 45%,
        #bd63c1 55%,
        #53e5a6 65%,
        transparent 85%
    );
}

.g-aurora {
    ...
    transform: rotate(45deg) scaleX(1.4);
}

.g-aurora {
    ...
    transform: rotate(45deg) scaleX(1.4);
    mix-blend-mode: color-dodge;
}

<p class="g-wrap">
  <p class="g-aurora"></p>
</p>

.g-aurora {
    ...
    transform: rotate(45deg) scaleX(1.4);
    mix-blend-mode: color-dodge;
    filter: url(#wave);
}

var filter = document.querySelector("#turbulence");
var frames = 0;
var rad = Math.PI / 180;

function freqAnimation() {
  bfx = 0.005;
  bfy = 0.005;
  frames += .5
  bfx += 0.0025 * Math.cos(frames * rad);
  bfy += 0.0025 * Math.sin(frames * rad);

  bf = bfx.toString() + ' ' + bfy.toString();
  filter.setAttributeNS(null, 'baseFrequency', bf);
  window.requestAnimationFrame(freqAnimation);
}

window.requestAnimationFrame(freqAnimation);