source for codepen.io/imjared/full/athzf.

logo.scss

@import "mathsass/dist/math.scss";

$radius: 12px;
$colors : (
  1: #746f86,
  2: #746f86,
  3: #a16e8f,
  4: #a16e8f,
  5: #a9637b,
  6: #a9637b,
  7: #d27484,
  8: #d27484,
  9: #b76861,
  10: #b76861,
  11: #d57867,
  12: #d57867,
  13: #d5835b,
  14: #d5835b
);

@each $color, $barColor in $colors {
    .color-#{$color} {
      .is-active & {
        .bar-inner {
          background: $barColor;
          height: pow((2.42*$color), 1.5) * 1px;
          transition-delay: ($color / 2) * 0.1s;
        }
      }
    }
}

.container {
  width: 200px;
  height: 200px;
  margin: 0 auto;
  display: flex;
}

.bar {
  background: #dad7c6;
  width: 100%;
  height: 100%;
  margin: 0 1px;
  border-radius: $radius;
  position: relative;
  // overflow: hidden;
}

.bar-inner {
  position: absolute;
  bottom: 0;
  width: 100%;
  border-radius: $radius;
  height: 0;
  transition: height 0.8s ease-in-out;
}

h1 {
  text-align: center;
  color: #746f86;
  font-family: 'Source Sans Pro', 'sans-serif';
  font-size: 30px;
  margin: 0;
  .the {
    font-style: italic;
    font-weight: 300;
  }
  span {
    opacity: 0;
    transition: opacity 0.8s;
    .is-active & {
      opacity: 1;
      transition-delay: 1.5s;
    }
  }
}

pow() yanked from https://github.com/terkel/mathsass