<!-- 主要借助了滤镜 blur contrast 的融合效果-->
<!-- 尝试注释掉这一行 filter: blur(20px) contrast(30) -->
<!-- 完整详细内容：https://github.com/chokcoco/iCSS/issues/30-->

.g-container
    .g-fire
        - for (var j = 1; j <=40; j++)
            .g-dot

$douCount: 40;
$animationTime: 2;
$delayTime: 3;

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

body {
    background: #000;
    overflow: hidden;
}

:root {
    --fireWidth: 115px;
    --fireHeight: 200px;
    --dotSize: 24px;
    --fireColor: #b5932f;
    // --fireColor: #008eff;
    // --fireColor: #ff9900;
    
}

.g-container {
    position: relative;
    width: 384px;
    height: 300px;
    margin: 0 auto;
    background-color: #000;
}

.g-fire {
    position: absolute;
    width: 0;
    height: 0;
    bottom: 100px;
    left: 50%;
    border-radius: 45%;
    box-sizing: border-box;
    border: 200px solid #000;
    border-bottom: 200px solid transparent;
    transform: translate(-50%, 0) scaleX(.4);
    background-color: var(--fireColor);
    filter: blur(20px) contrast(30);
}

.g-dot {
    position: absolute;
    bottom: -210px;
    left: 0;
    width: var(--dotSize);
    height: var(--dotSize);
    background: #000;
    border-radius: 50%;
}

@for $i from 1 to $douCount + 1 {
    .g-dot:nth-child(#{$i}) {
        bottom: -#{randomNum(120, 240)}px;
        left: #{randomNum(300, -160)}px;
        animation: move #{randomNum($animationTime * 13, 7) / 10}s infinite #{randomNum($delayTime * 20) / 10}s linear;
    }
}

@keyframes move {
    100% {
        transform: translate3d(0, -350px, 0);
    }
}