Cacher is the code snippet organizer for pro developers

<h3>BEM Button - Helper klase</h3>

<a class="button" href="#">
  <span class="button__label">
    BEM button - normal
  </span>
</a>

<!-- TODO: maknuti hover i pointer -->
<a class="button is_disabled" href="#">
  <span class="button__label">
    BEM button - is_disabled
  </span>  
</a>

<a class="button is_alert has_icon" href="#">
  <span class="button__label">
    BEM button - is_alert, has_icon
  </span>
</a>

.button {
  display: inline-block;
  padding: 5px 10px;
  color: white;
  text-decoration: none;
  text-shadow: 1px 1px 0 rgba(0, 0, 0, 0.5);
  font-family: sans-serif;
  background: LightSlateGray;
  border-radius: 3px;
  box-shadow: 0 0 2px rgba(0, 0, 0, 0.5);
}

.button:hover {
  box-shadow: none;
}
.button.is_disabled {
  background: #ccc;
  color: #aaa;
}
.button.has_icon {
  padding-left: 5px;
}
.button__label {
  font-weight: bold;
}
.button.is_alert .button__label {
  color: gold;
}

.button.has_icon .button__label {
  padding-left: 5px;
}
.button.has_icon .button__label:before {
  content: "!";
  color: gold;
}

// ----
// Sass (v3.3.9)
// Compass (v1.0.0.alpha.20)
// ----

// BEM Button - Helper klase

// $m je varijabla naziva modula / bloka
// koristimo ga jer je kraće nego uvijek pisati sam naziv
$m: button;
%#{$m} {
  display: inline-block;
  padding: 5px 10px;
  color: white;
  text-decoration: none;
  text-shadow: 1px 1px 0 rgba(0,0,0,0.5);
  font-family: sans-serif;
  background: LightSlateGray;
  border-radius: 3px;
  box-shadow: 0 0 2px rgba(0,0,0,0.5);
}

// START
.#{$m}{
  @extend %#{$m}; 
  
  &:hover {
    box-shadow: none;
  }
  
  // stanje gumba je - disabled
  &.is_disabled {
    background: #ccc;
    color: #aaa;
  }
  // gumb sadrži ikonu
  &.has_icon{
    padding-left: 5px;
  }
  
  // .button__label
  &__label{
    font-weight: bold;
    
    // sve je na jednom mjestu odnosno - pod button__label
    // vraća se u root, uzima prefix is_alert i has_icon
    // a & vraća putanju selektora u kojem se nalazimo
    @at-root  {
      
      .#{$m}.is_alert &{
        color: gold;
      }
      
      .#{$m}.has_icon &{
        padding-left: 5px;
        &:before {
          content:"!";
          color: gold;
        }
      }
    }
  }
}

<h3>BEM Button - Helper klase</h3>

<a class="button" href="#">
  <span class="button__label">
    BEM button - normal
  </span>
</a>

<!-- TODO: maknuti hover i pointer -->
<a class="button is_disabled" href="#">
  <span class="button__label">
    BEM button - is_disabled
  </span>  
</a>

<a class="button is_alert has_icon" href="#">
  <span class="button__label">
    BEM button - is_alert, has_icon
  </span>
</a>