Laser Etch

const css = `
  @property --btn-laser-etch-p { syntax: '<percentage>'; inherits: true; initial-value: 0%; }
  /* The beam switches off once the pass is done. */
  @keyframes btn-laser-etch-beam {
    0%, 92% { opacity: 1; }
    100% { opacity: 0; }
  }
  @keyframes btn-laser-etch-spark {
    from { transform: translate(0, 0) scale(1); opacity: 1; }
    to { transform: translate(var(--sx), var(--sy)) scale(0.3); opacity: 0; }
  }
  .btn-laser-etch {
    --btn-laser-etch-p: 0%;
    position: relative;
    display: grid;
    place-items: center;
    width: 200px;
    height: 60px;
    padding: 0;
    border: 1px solid light-dark(#dbdde1, #2e3035);
    border-radius: 10px;
    background: light-dark(#f3f4f7, #1a1c1f);
    font-family: inherit;
    cursor: pointer;
    transition: --btn-laser-etch-p 0.35s cubic-bezier(0.4, 0, 1, 1), border-color 0.3s ease;
  }
  .btn-laser-etch:hover, .btn-laser-etch:focus-visible {
    --btn-laser-etch-p: 100%;
    border-color: light-dark(#6d7179, #7d8087);
    transition: --btn-laser-etch-p 1.1s linear, border-color 0.3s ease;
  }
  .btn-laser-etch:focus-visible { outline: 2px solid light-dark(#42454c, #e5e6e9); outline-offset: 3px; }
  /* Both copies span the whole button, so the etch and the beam share one coordinate. */
  .btn-laser-etch__text {
    grid-area: 1 / 1;
    justify-self: stretch;
    text-align: center;
    font-size: 22px;
    font-weight: 600;
    letter-spacing: 0.12em;
    text-transform: uppercase;
  }
  .btn-laser-etch__text--outline {
    color: transparent;
    -webkit-text-stroke: 1px light-dark(#6d7179, #7d8087);
  }
  .btn-laser-etch__text--etched {
    color: light-dark(#373a40, #f1f2f3);
    clip-path: inset(0 calc(100% - var(--btn-laser-etch-p)) 0 0);
    text-shadow: 0 0 8px color-mix(in oklab, light-dark(#373a40, #f1f2f3) 40%, transparent);
  }
  .btn-laser-etch__beam {
    position: absolute;
    top: 6px;
    bottom: 6px;
    left: var(--btn-laser-etch-p);
    width: 2px;
    margin-left: -1px;
    border-radius: 2px;
    background: light-dark(#373a40, #f1f2f3);
    box-shadow: 0 0 8px 1px light-dark(#373a40, #f1f2f3), 0 0 18px 4px color-mix(in oklab, light-dark(#373a40, #f1f2f3) 35%, transparent);
    opacity: 0;
    transition: opacity 0.2s ease;
  }
  .btn-laser-etch:hover .btn-laser-etch__beam,
  .btn-laser-etch:focus-visible .btn-laser-etch__beam { animation: btn-laser-etch-beam 1.2s linear forwards; }
  .btn-laser-etch__spark {
    position: absolute;
    left: 0;
    top: 50%;
    width: 3px;
    height: 3px;
    border-radius: 50%;
    background: light-dark(#373a40, #f1f2f3);
    opacity: 0;
  }
  .btn-laser-etch:hover .btn-laser-etch__spark,
  .btn-laser-etch:focus-visible .btn-laser-etch__spark { animation: btn-laser-etch-spark 0.45s ease-out var(--d) infinite; }
  @media (prefers-reduced-motion: reduce) {
    .btn-laser-etch, .btn-laser-etch:hover { transition: none; }
    .btn-laser-etch__beam, .btn-laser-etch__spark { display: none; }
  }
`;

const SPARKS = [
  { sx: '9px', sy: '-14px', d: '0s' },
  { sx: '-12px', sy: '6px', d: '0.12s' },
  { sx: '6px', sy: '16px', d: '0.24s' },
  { sx: '16px', sy: '-5px', d: '0.06s' },
  { sx: '-9px', sy: '12px', d: '0.31s' },
  { sx: '7px', sy: '-18px', d: '0.18s' },
];

export function LaserEtchButton() {
  return (
    <>
      <style>
        {css}
      </style>
      <button type="button" className="btn-laser-etch" aria-label="Engrave">
        <span className="btn-laser-etch__text btn-laser-etch__text--outline" aria-hidden="true">
          Engrave
        </span>
        <span className="btn-laser-etch__text btn-laser-etch__text--etched" aria-hidden="true">
          Engrave
        </span>
        <span className="btn-laser-etch__beam" aria-hidden="true">
          {SPARKS.map((s, i) => (
            <span
              key={i}
              className="btn-laser-etch__spark"
              style={{ '--sx': s.sx, '--sy': s.sy, '--d': s.d } as React.CSSProperties}
            />
          ))}
        </span>
      </button>
    </>
  );
}