Property Declarations And Placeholder

// Property Declarations And Placeholder

.box {
  font-size: 20px;
  font: {
    size: 15px;
    weight: bold;
  }
  padding: 10px;
  margin: auto {
    top: 10px;
    bottom: 15px;
  }
}

%main-box {
  background-color: white;
  padding: 15px;
  border: 1px solid #ccc;
}

.ads {
  @extend %main-box;
  font-size: 20px;
  color: red;
}

.article {
  font-size: 22px;
  @extend %main-box;
  color: green;
}