modernscale.css

body {
  font-size: 100%;
}

body, caption, th, td, input, textarea, select, option, legend, fieldset, h1, h2, h3, h4, h5, h6 {
  font-size-adjust: 0.5;
}

#page {
  font-size: 1em;
  /* equivalent to 16px */
  line-height: 1.25;
  /* equivalent to 20px */
}

@media (min-width: 43.75em) {
  #page {
    font-size: 1em;
    /* equivalent to 16px */
    line-height: 1.375;
    /* equivalent to 22px */
  }
}

h1 {
  font-size: 2em;
  /* 2x body copy size = 32px */
  line-height: 1.25;
  /* 45px / 36px */
}

@media (min-width: 43.75em) {
  h1 {
    font-size: 2.5em;
    /* 2.5x body copy size = 40px */
    line-height: 1.125;
  }
}

@media (min-width: 56.25em) {
  h1 {
    font-size: 3em;
    /* 3x body copy size = 48px */
    line-height: 1.05;
    /* keep to a multiple of the 20px line height and something more appropriate for display headings */
  }
}

h2 {
  font-size: 1.625em;
  /* 1.625x body copy size = 26px */
  line-height: 1.15384615;
  /* 30px / 26px */
}

@media (min-width: 43.75em) {
  h2 {
    font-size: 2em;
    /* 2x body copy size = 32px */
    line-height: 1.25;
  }
}

@media (min-width: 56.25em) {
  h2 {
    font-size: 2.25em;
    /* 2.25x body copy size = 36px */
    line-height: 1.25;
  }
}

h3 {
  font-size: 1.375em;
  /* 1.375x body copy size = 22px */
  line-height: 1.13636364;
  /* 25px / 22px */
}

@media (min-width: 43.75em) {
  h3 {
    font-size: 1.5em;
    /* 1.5x body copy size = 24px */
    line-height: 1.25;
  }
}

@media (min-width: 56.25em) {
  h3 {
    font-size: 1.75em;
    /* 1.75x body copy size = 28px */
    line-height: 1.25;
  }
}

h4 {
  font-size: 1.125em;
  /* 1.125x body copy size = 18px */
  line-height: 1.11111111;
}

@media (min-width: 43.75em) {
  h4 {
    line-height: 1.22222222;
    /* (22px / 18px */
  }
}

blockquote {
  font-size: 1.25em;
  /* 20px / 16px */
  line-height: 1.25;
  /* 25px / 20px */
}

@media (min-width: 43.75em) {
  blockquote {
    font-size: 1.5em;
    /* 24px / 16px = */
    line-height: 1.45833333;
    /* 35px / 24px */
  }
}