Cacher is the code snippet organizer for pro developers

THE BIGGEST DIFFERENCE BETWEEN EXTEND AND MIXIN - 
!WHEN YOU ADD MIXIN TO A CLASS, IT COPIES MIXIN'S CONTENT INTO A CLASS!
!WHEN YOU ADD AN EXTEND TO A CLASS, IT COPIES A NAME OF ALL CLASSES WITH THAT EXTEND AND CREATES A NEW BLOCK OF CSS VALUES!

EXTENDS SHOULD WORK WITH RELATED ELEMENTS ONLY

<nav>
  <ul class="navigation"
      <li><a href="#">About Us</a></li>
      <li><a href="#">Pricing</a></li>
      <li><a href="#">Contact</a></li>
  </ul>
  <div class="button">
    <a class="btn-main" href="#">Sign Up</a>
    <a class="btn-hot" href="#">Get a Quote</a>
  </div>
</nav>


* {
  margin: 0;
  padding: 0;
}

$color-primary: #f9ed69;
$color-secondary: #f08a5d;
$color-tertiary: #b83b5e;
$color-text-dark: #333;
$color-text-light: #eee;
$width-button: 150px;

@mixin clearfix {
  &::after { //fixes collapsed element (floats)//
    content: "";
    clear: both;
    display: table;
  }
}

@mixin style-link-text($col) {
   text-decoration: none;
   text-transform: uppercase;
   color: $col;
}

@function divide($a, $b) {
  @return ($a / $b) * 1px;
}

nav {
  margin:divide(60,2); //30px
  background-color: $color-primary;
  
  @include clearfix;
}

.navigation {
  list-style:none;
  float: left;
  
  li {
    display: inline-block;
    margin-left: 30px;
    
    &:first-child {
      margin: 0;
    }
    
    a:link {
      @include style-link-text($color-text-dark);
    }
  }
}

.button {
  float: right;
}

%btn-placeholder {
  padding: 10px;
  display: inline-block;
  text-align: center;
  border-radius: 100px;
  width: $width-button;
  @include style-link-text($color-text-light);
}

.btn-main {
  &:link {
    @extend %btn-placeholder;
    background-color: $color-secondary;
  }
  
  &:hover {
    background-color: darken($color-secondary, 15%); //inbuilt sass function
  }
}

.btn-hot {
  &:link {
    @extend %btn-placeholder;
    background-color: $color-tertiary;
  }
  
  &:hover {
    background-color: lighten($color-tertiary, 15%); //inbuilt sass function
  }
}