scale.js

const getFontSize = (textLength) => {
  const baseSize = 9
  if (textLength >= baseSize) {
    textLength = baseSize - 2
  }
  const fontSize = baseSize - textLength
  return `${fontSize}vw`
}

const boxes = document.querySelectorAll('.content h1')
  
boxes.forEach(box => {
  box.style.fontSize = getFontSize(box.textContent.length)
})