/* ピクセルとdpi、ppi、dppxと解像度の話  < http://scene-live.com/smart/page.php?page=94 > */
/* CSSを使ってフォントサイズを変更する方法｜さきちんWEB < http://sakichin.com/chapter02/chapter02_step03_02.html > */
/* いまさら聞けないRetina対応のための「ピクセル」の話 | Rriver < https://parashuto.com/rriver/development/pixel-related-info-for-coping-with-retina-displays > */
/*
 * calc と  var でまとめられないかねぇ？ calc (4px * (2 * var(min-resolusion, var(-webkit-min-device-pixel-ratio, 1.0)) ))
 * calc はだいたい対応済みらしいが var はまだ少ないみたい　2018/01/13
 */
@media only screen and (min-resolution: 1.5dppx), only screen and (-webkit-min-device-pixel-ratio: 1.5) {
body { font-size:calc(4px * (2 * 2  )); } /* 16px */
}
@media only screen and (min-resolution:   2dppx), only screen and (-webkit-min-device-pixel-ratio: 2  ) {
body { font-size:calc(4px * (2 * 2.5)); } /* 20px */
}
@media only screen and (min-resolution: 2.5dppx), only screen and (-webkit-min-device-pixel-ratio: 2.5) {
body { font-size:calc(4px * (2 * 3 )); } /* 24px */
}
@media only screen and (min-resolution:   3dppx), only screen and (-webkit-min-device-pixel-ratio: 3  ) {
body { font-size:calc(4px * (2 * 3.5)); } /* 28px */
}
@media only screen and (min-resolution: 3.5dppx), only screen and (-webkit-min-device-pixel-ratio: 3.5) {
body { font-size:calc(4px * (2 * 4  )); } /* 32px */
}
@media only screen and (min-resolution:   4dppx), only screen and (-webkit-min-device-pixel-ratio: 4  ) {
body { font-size:calc(4px * (2 * 4.5)); } /* 36px */
}
@media only screen and (min-resolution:   5dppx), only screen and (-webkit-min-device-pixel-ratio: 5  ) {
body { font-size:calc(4px * (2 * 6  )); } /* 48px */
}
@media only screen and (min-resolution:   6dppx), only screen and (-webkit-min-device-pixel-ratio: 6  ) {
body { font-size:calc(4px * (2 * 7  )); } /* 56px */
}