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div.o-parent
section.c-region
h1.c-region__title Title
p.c-region__subtitle Subtitle
nav.c-region__nav
a(href="#") Link
a(href="#") Link
section
h1 The multiplier
p A quick check across the elements will show you that each right and left margin of siblings also sums to 12. The margins on each element sum to 12 minus the fr unit width of that element.
ul
li g = fixed width of gutter
li c = number of columns
li m = multiplier
p margin-right: g/c * m
p margin-left: g/c * m
p Sum the fr units to the left and right positions to get the multiplier:
p
code grid-template-columns: 2fr 3fr 2fr 4fr 1fr
ul
li 2fr : margin-left: g/c * 0 ; margin-right: g/c * 10 ( 3 + 2 + 4 + 1)
li 3fr : margin-left: g/c * 2 (2 + 0); margin-right: g/c * 7 (2 + 4 + 1)
li 2fr : margin-left: g/c * 5 (0 + 2 + 3); margin-right: g/c * 5 (4 + 1)
li 4fr : margin-left: g/c * 7 ( 2 + 3 + 2 ); margin-right: g/c * 1 (1 +0)
li 1fr : margin-left: g/c * 11 (4 + 2 + 3 + 2) ; margin-right: g/c * 0
div.spacer
// the ONLY case in which you would do this is where:
//1. you are using named areas AND
//2. those areas are sized in fr
$b: 1.25rem; // base spacing unit of site
$cols: 12; // parent grid has 12 cols
@mixin alignToParent($map){
$i: 1; // start the count at 1 for items in map
$m: 0; // set multiplier to 0 as first margin is always 0
$g: $b/$cols; // gutter is the base spacing unit divided by the number of cols in the parent grid
@each $key, $value in $map {
&__#{$key} {
margin-left:calc(#{$g} * #{$m});
$m: $m + $value; //add the current fr unit to pass to the next element as multiplier
@if $i == length($map) { //if we have reached the end of the columns we set the margin to 0
margin-right: 0; //end
} @else {
$r: $cols - $m; //right hand margin is the inverse, so subtract from number of $cols
margin-right:calc(#{$g} * #{$r});
$i: $i + 1; //otherwise increment our counter and go round again
}
}
}
}
// include autoassign mixin
//https://codepen.io/Sally_McGrath/pen/wQyzBX
@mixin template($elements...) {
@each $element in $elements {
&__#{$element} {
grid-area: $element;
}
}
}
/// now apply margins
.c-region {
display:grid;
align-items:center;
@include template(title,subtitle,nav);
grid-template-areas:
"title subtitle nav";
grid-template-columns: 5fr 3fr 4fr;
$assign: (title: 5, subtitle: 3, nav: 4);
@include alignToParent($assign);
}
.o-parent {
display: grid;
grid-template-columns: repeat($cols, 1fr);
grid-gap: $b;
> * {grid-column: 1/-1}
}
//ignore this, just to make something show up
body{font:1em Futura,sans-serif;}
.c-region {
$p: &;
>* {background: pink; height:100%}
}
.spacer {min-height:50vh}
Also see: Tab Triggers