How can I force all page elements to inherit the font size from the body and not from the immediate parent in em units?

Question

css

I'm doing a responsive layout and would like to transfer all fonts, margins, padding values ​​to em units. But when setting the font size on the parent, the element automatically multiplies it by the number of ems, even though I want the BODY size (16px(default for all) * 62.5% = 10 | 1.6em = 16px -- in the entire document). How to cancel inheritance, or somehow get around it? Here is the part of the code where the SPAN element multiplies the font-size from .LOGO by 2, which gives 80px. I'm counting on 20:

html, body, div, span, applet, object, iframe,
h1, h2, h3, h4, h5, h6, p, blockquote, pre,
a, abbr, acronym, address, big, cite, code,
del, dfn, em, img, ins, kbd, q, s, samp,
small, strike, strong, sub, sup, tt, var,
b, u, i, center,
dl, dt, dd, ol, ul, li,
fieldset, form, label, legend,
table, caption, tbody, tfoot, thead, tr, th, td,
article, aside, canvas, details, embed,
figure, figcaption, footer, header, hgroup,
main, menu, nav, output, ruby, section, summary,
time, mark, audio, video {
  margin: 0;
  padding: 0;
  box-sizing: border-box;

  // includes margins and paddings
  // in heigth and width of every element on the page
  // 16px(default for all) * 62.5% = 10 | 1.6em = 16px
  font: 62.5% $regular;
  font: inherit;
  border: 0;
  vertical-align: baseline;
}

/* HTML5 display-role reset for older browsers */
article, aside, details, figcaption, figure,
footer, header, hgroup, main, menu, nav, section {
  display: block;
}

ol, ul {
  list-style: none;
}

a {
  text-decoration: none;
}

blockquote, q {
  quotes: none;

  &:before, &:after {
    content: '';
    content: none;
  }
}

table {
  border-collapse: collapse;
  border-spacing: 0;
}

header, section, footer {
  font-size: 1.6em;
  padding: 2em;
  margin: 0 auto;
}

/* ========================================================
   || Begining
   ======================================================== */

header .row {
  background-color: #76c7c0;
  height: 80px;

  .logo {
    font: 2.5em $regular;
    span {
      font: 2em $extrabold;
    }
    color: #fff;
  }
}

Answer 1

How to undo inheritance

1em = font size of the parent element
1rem = font size of the root ( :root ) element, in this case html
You probably need to use rem units.