KNACSS/sass/_library/_base.scss

/* ----------------------------- */
/* ==Base (basic styles)         */
/* ----------------------------- */

$color-base      : $gray-900 !default;
$background-base : $white !default;

$link-color            : $gray-800 !default;
$link-color-hover      : darken($link-color, 15%) !default;
$link-decoration       : underline !default;
$link-decoration-hover : underline !default;

$quote-color     : $gray-200 !default;

// Default margin-bottom
$margin-bottom-base     : 1rem !default;
$headings-margin-bottom : $margin-bottom-base /2 !default;
$paragraph-margin-bottom: $margin-bottom-base !default;

// Line heights
$line-height-s    : 1.3 !default;
$line-height-base : 1.5 !default;
$line-height-l    : 1.7 !default;

// Font weights
$weight-light   : 200 !default;
$weight-book    : 300 !default;
$weight-regular : 400 !default;
$weight-medium  : 500 !default;
$weight-bold    : 700 !default;

// Activate hyphenation on small screens
$hyphens: false !default;

// Font families
$font-family-base      : -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen-Sans, Ubuntu, Cantarell, "Helvetica Neue", sans-serif !default; // system font stack
$font-family-headings  : sans-serif !default; // font for h1, h2.. h6
$font-family-monospace : consolas, courier, monospace !default; // font for code and samples

// Font sizes (1.6rem value is "16px" equivalent)
$font-size-base : 1.6rem !default;

$font-sizes: (
  base: (
    mobile  : 1.4rem,
    desktop : $font-size-base
  ),
  h1: (
    mobile  : 2.8rem,
    desktop : 3.2rem
  ),
  h2: (
    mobile  : 2.4rem,
    desktop : 2.8rem
  ),
  h3: (
    mobile  : 2.0rem,
    desktop : 2.4rem
  ),
  h4: (
    mobile  : 1.8rem,
    desktop : 2.0rem
  ),
  h5: (
    mobile  : 1.6rem,
    desktop : 1.8rem
  ),
  h6: (
    mobile  : 1.4rem,
    desktop : 1.6rem
  )
) !default;

/* switching to border-box model for all elements */
html {
  box-sizing: border-box;
}

*,
*::before,
*::after {
  box-sizing: inherit;
  /* avoid min-width: auto on flex and grid children */
  min-width: 0;
  min-height: 0;
}

html {
  /* set base font-size to equiv "10px", which is adapted to rem unit */
  font-size: 62.5%;
  /* IE9-IE11 math fixing. See http://bit.ly/1g4X0bX */
  font-size: calc(1em * 0.625);
}

body {
  margin: 0;
  @include font-size(base);
  background-color: $background-base;
  color: $color-base;
  font-family: $font-family-base;
  line-height: $line-height-base;
}

/* Links */
a {
  color: $link-color;
  text-decoration: $link-decoration;

  &:focus,
  &:hover,
  &:active {
    color: $link-color-hover;
    text-decoration: $link-decoration-hover;
  }
}

/* Headings */
h1, .h1-like {
  @include font-size(h1);
  @if variable_exists(font-family-headings) and $font-family-headings != $font-family-base{
    font-family: $font-family-headings;
  }
  font-weight: $weight-medium;
}

h2, .h2-like {
  @include font-size(h2);
  @if variable_exists(font-family-headings) and $font-family-headings != $font-family-base{
    font-family: $font-family-headings;
  }
  font-weight: $weight-medium;
}

h3, .h3-like {
  @include font-size(h3);
  font-weight: $weight-medium;
}

h4, .h4-like {
  @include font-size(h4);
  font-weight: $weight-medium;
}

h5, .h5-like {
  @include font-size(h5);
  font-weight: $weight-medium;
}

h6, .h6-like {
  @include font-size(h6);
  font-weight: $weight-medium;
}

/* Vertical rythm */
h1,
h2,
h3,
h4,
h5,
h6,
dd {
  margin-top: 0;
  margin-bottom: $headings-margin-bottom;
}

p,
address,
ol,
ul,
dl,
blockquote,
pre {
  margin-top: 0;
  margin-bottom: $paragraph-margin-bottom;
}

/* Avoid margins on nested elements */
li p,
li .p-like,
li ul,
li ol,
ol ol,
ul ul {
  margin-top: 0;
  margin-bottom: 0;
}

/* Max values */
img,
table,
td,
blockquote,
code,
pre,
textarea,
input,
video,
svg {
  max-width: 100%;
}

img {
  height: auto;
}

/* Styling elements */
ul,
ol {
  padding-left: 2em;
}

img {
  vertical-align: middle;
}

em,
.italic,
address,
cite,
i,
var {
  font-style: italic;
}

code,
kbd,
mark {
  border-radius: 2px;
}

kbd {
  padding: 0 2px;
  border: 1px solid #999;
}

pre {
  tab-size: 2;
}

code {
  padding: 2px 4px;
  background: rgba(0, 0, 0, 0.04);
  color: #b11;
}

pre code {
  padding: 0;
  background: none;
  color: inherit;
  border-radius: 0;
}

mark {
  padding: 2px 4px;
}

sup,
sub {
  vertical-align: 0;
}

sup {
  bottom: 1ex;
}

sub {
  top: 0.5ex;
}

blockquote {
  position: relative;
  padding-left: 3em;
  min-height: 2em;
}

blockquote::before {
  content: "\201C";
  position: absolute;
  left: 0;
  top: 0;
  font-family: georgia, serif;
  font-size: 5em;
  height: .4em;
  line-height: .9;
  color: $quote-color;
}

blockquote > footer {
  margin-top: .75em;
  font-size: 0.9em;
  color: rgba(0, 0, 0, .7);

  &::before {
    content: "\2014 \0020";
  }
}

q {
  font-style: normal;
}

q,
.q {
  quotes: "“" "”" "‘" "’";

  &:lang(fr) {
    quotes: "«\00a0" "\00a0»" "“" "”";
  }
}

hr {
  display: block;
  clear: both;
  height: 1px;
  margin: 1em 0 2em;
  padding: 0;
  border: 0;
  color: #ccc;
  background-color: #ccc;
}

blockquote,
figure {
  margin-left: 0;
  margin-right: 0;
}

code,
pre,
samp,
kbd {
  white-space: pre-wrap;
  font-family: $font-family-monospace;
  line-height: normal;
}