Letter Cascade

This is a per-letter reveal animation I built entirely with CSS - no JavaScript timing loop, no animation library, just a single custom property doing the heavy lifting.

Each letter gets its own --index, set inline via style={{ '--index': i }} on the span. That value feeds animation-delay: calc(0.03s * var(--index)), so instead of every letter starting at once, each one waits a little longer than the last - letter 0 starts immediately, letter 9 starts 270ms later. That's what gives you the cascade instead of a flat pop-in.

One detail I almost missed: animation-fill-mode: backwards. Without it, every letter flashes into its final position for a frame before its delay kicks in, which looks broken. With backwards, each letter just holds still - translated out of view - until its turn comes up. The easing, a cubic-bezier(.075, .82, .165, 1) curve, slows down hard right at the end so it settles instead of overshooting and bouncing.

LetterCascade.tsx

import './styles.css'

import React from 'react'

export function LetterCascade() {
  return (
      <h1 className={'h1'}>
          {[...'Animations'].map((l, i) => (
              <span
                  key={`${i}-${l}}`}
                  className={'letter'}
                  style={{ '--index': i }}
              >
                  {l}
              </span>
          ))}
      </h1>
  )
}

styles.css

.h1 {
    font-size: clamp(32px, 5vw, 48px);
    font-weight: 600;
    letter-spacing: -0.05em;
    overflow: hidden;
    color: white;
}
.letter {
    display: inline-block;
    animation: yTranslate 1.3s cubic-bezier(.075, .82, .165, 1);
    animation-delay: calc(0.03s * var(--index));
    animation-fill-mode: backwards;
}
.button {
    width: 100%;
    margin-top: 24px;
    position: relative;
    height: 32px;
    font-size: 14px;
    padding-inline: 12px;
    font-weight: 500;
    border-radius: 9999px;
    background: #fff;
    box-shadow:
            0 0 0 1px rgba(0, 0, 0, 0.08),
            0px 2px 2px rgba(0, 0, 0, 0.04);
}

@keyframes yTranslate {
    from {
        transform: translateY(100%)
    }
    to {
        transform: translateY(0);
    }
}

@media (prefers-reduced-motion: reduce) {
    .letter {
        animation: none;
    }
}

It also respects prefers-reduced-motion - if you've told your OS you'd rather skip animations, you just get the final text straight away, no cascade, no fuss.