Css calc ()函数中的 Sass 变量

I'm trying to use the calc() function in a Sass stylesheet, but I'm having some issues. Here's my code:

$body_padding: 50px

body
    padding-top: $body_padding
    height: calc(100% - $body_padding)

If I use the literal 50px instead of my body_padding variable, I get exactly what I want. However, when I switch to the variable, this is the output:

body {
    padding-top: 50px;
    height: calc(100% - $body_padding); }

How can I get Sass to recognize that it needs to replace the variable within the calc function?

Interpolate:

body
    height: calc(100% - #{$body_padding})

For this case, border-box would also suffice:

body
    box-sizing: border-box
    height: 100%
    padding-top: $body_padding

Try this:

@mixin heightBox($body_padding){
   height: calc(100% - $body_padding);
}

body{
   @include heightBox(100% - 25%);
   box-sizing: border-box
   padding:10px;
}

To use $variables inside your calc() of the height property :

Html

<div></div>

Scss

$a: 4em;

div {
  height: calc(#{$a} + 7px);
  background: #e53b2c;
}

Here is a really simple solution using SASS/SCSS and a math formula style:

/* frame circle */
.container {
    position: relative;
    border-radius: 50%;
    background-color: white;
    overflow: hidden;
    width: 400px;
    height: 400px; }

/* circle sectors */
.menu-frame-sector {
    position: absolute;
    width: 50%;
    height: 50%;
    z-index: 10000;
    transform-origin: 100% 100%;
  }

$sector_count: 8;
$sector_width: 360deg / $sector_count;

.sec0 {
    transform: rotate(0 * $sector_width) skew($sector_width);
    background-color: red; }
.sec1 {
    transform: rotate(1 * $sector_width) skew($sector_width);
    background-color: blue; }
.sec2 {
    transform: rotate(2 * $sector_width) skew($sector_width);
    background-color: red; }
.sec3 {
    transform: rotate(3 * $sector_width) skew($sector_width);
    background-color: blue; }
.sec4 {
    transform: rotate(4 * $sector_width) skew($sector_width);
    background-color: red; }
.sec5 {
    transform: rotate(5 * $sector_width) skew($sector_width);
    background-color: blue; }
.sec6 {
    transform: rotate(6 * $sector_width) skew($sector_width);
    background-color: red; }
.sec7 {
    transform: rotate(7 * $sector_width) skew($sector_width);
    background-color: blue; }

To conclude, I strongly suggest you to understand transform-origin, rotate() and skew():

https://tympanus.net/codrops/2013/08/09/building-a-circular-navigation-with-css-transforms/