FulidPlyr.js

const FulidPlyr = (parentSelector) => {
  if (parentSelector === undefined) {
    parentSelector = '.FulidPlyr'
  }

  let element = document.querySelector(parentSelector)
  let ratio = 16 / 9
  let height = window.innerHeight
  let width = window.innerWidth
  let windowRatio = width / height
  let margin = {
    x: 0,
    y: 0
  }

  if (windowRatio > ratio) {
    // console.log('横長')
    let newHeight = Math.ceil((width / ratio - height) / 2)
    margin.y = -newHeight + 'px'
  } else if (windowRatio < ratio) {
    // console.log('縦長')
    let newWidth = height * ratio
    margin.x = Math.floor((newWidth - width) / -2) - 8 + 'px'
  }

  element.style.marginLeft = margin.x
  element.style.marginRight = margin.x
  element.style.marginTop = margin.y
}

export default FulidPlyr