Generated by SassMeister.com.

SassMeister-input-HTML.html

<div class="m-box">
  <h3 class="m-box--header">Some buttons</h3>
  <div class="m-box--body">
    <a class="m-button">Button</a>
    <a class="m-button as-small">Small button</a>
    <a class="m-button">
      <i class="m-button--icon">€</i>
      Button with icon
    </a>
    <a class="m-button is-disabled">
      Button disabled
    </a>
    <a class="m-button as-small is-disabled">
      <i class="m-button--icon">€</i>
      Small disabled button with icon
    </a>
    <a class="m-button_secondary">
      <i class="m-button--icon">€</i>
      Secondary button submodule
    </a>
  </div>
</div>

<div class="m-box as-highlighted">
  <h1 class="m-box--header">Highlighted box</h1>
  <p class="m-box--body">Box body:  Lorem ipsum text</p>
</div>

SassMeister-input.sass

// ----
// Sass (v3.3.7)
// Compass (v1.0.0.alpha.18)
// ----

// ---- button ----

// module
.m-button
  background-color: orange
  border-radius: 5px
  padding: 5px 10px
  text-decoration: none
  display: inline-block
  cursor: pointer

  // modifier
  &.as-small
    font-size: 80%
    padding: 2px 5px

  // state
  &.is-disabled
    background-color: silver
    cursor: default
    opacity: .5

// sub component
.m-button--icon
  background-color: white
  border-radius: 100%
  width: 1em
  display: inline-block
  text-align: center

// sub module
.m-button_secondary
  @extend .m-button
  background-color: lightblue
  text-decoration: line-through


// ---- box ----

// module
.m-box
  border: 1px solid black
  margin-bottom: 20px

// sub component
.m-box--header
  font-weight: bold
  text-decoration: underline
  padding: 0px 10px
  background-color: #ccc
  margin: 0
  padding: 10px

// sub component
.m-box--body
  padding: 10px

// modifier that also applies to sub component
.m-box
  &.as-highlighted
    border-color: green
  
    .m-box--header
      background-color: yellow



  

SassMeister-output.css

.m-button, .m-button_secondary {
  background-color: orange;
  border-radius: 5px;
  padding: 5px 10px;
  text-decoration: none;
  display: inline-block;
  cursor: pointer;
}
.m-button.as-small, .as-small.m-button_secondary {
  font-size: 80%;
  padding: 2px 5px;
}
.m-button.is-disabled, .is-disabled.m-button_secondary {
  background-color: silver;
  cursor: default;
  opacity: 0.5;
}

.m-button--icon {
  background-color: white;
  border-radius: 100%;
  width: 1em;
  display: inline-block;
  text-align: center;
}

.m-button_secondary {
  background-color: lightblue;
  text-decoration: line-through;
}

.m-box {
  border: 1px solid black;
  margin-bottom: 20px;
}

.m-box--header {
  font-weight: bold;
  text-decoration: underline;
  padding: 0px 10px;
  background-color: #cccccc;
  margin: 0;
  padding: 10px;
}

.m-box--body {
  padding: 10px;
}

.m-box.as-highlighted {
  border-color: green;
}
.m-box.as-highlighted .m-box--header {
  background-color: yellow;
}

SassMeister-rendered.html

<div class="m-box">
  <h3 class="m-box--header">Some buttons</h3>
  <div class="m-box--body">
    <a class="m-button">Button</a>
    <a class="m-button as-small">Small button</a>
    <a class="m-button">
      <i class="m-button--icon">€</i>
      Button with icon
    </a>
    <a class="m-button is-disabled">
      Button disabled
    </a>
    <a class="m-button as-small is-disabled">
      <i class="m-button--icon">€</i>
      Small disabled button with icon
    </a>
    <a class="m-button_secondary">
      <i class="m-button--icon">€</i>
      Secondary button submodule
    </a>
  </div>
</div>

<div class="m-box as-highlighted">
  <h1 class="m-box--header">Highlighted box</h1>
  <p class="m-box--body">Box body:  Lorem ipsum text</p>
</div>