Generated by SassMeister.com.

SassMeister-input.scss

// Buttons
// ".btn-{modifiername}", background-color, border, color
$buttons: (
  ("primary", #2F9ED8, #2886B7, #FFFFFF),
  ("secondary", #FFFFFF, #DDDDDD, #101010)
);

// Generate Button Modifiers 
@each $b in $buttons {
  .btn.btn-#{nth($b,1)} {
    background-color: #{nth($b,2)};
    border-color: #{nth($b,3)};
    color: #{nth($b,4)};
  }
}

// Base Button
.btn {
  display: inline-block;
  border: 1px solid transparent;
  padding: 0.5rem 1rem;
  border-radius: 3px;
  font-family: sans-serif;
}

SassMeister-output.css

.btn.btn-primary {
  background-color: #2F9ED8;
  border-color: #2886B7;
  color: #FFFFFF;
}

.btn.btn-secondary {
  background-color: #FFFFFF;
  border-color: #DDDDDD;
  color: #101010;
}

.btn {
  display: inline-block;
  border: 1px solid transparent;
  padding: 0.5rem 1rem;
  border-radius: 3px;
  font-family: sans-serif;
}

SassMeister-rendered.html

<a class="btn btn-primary">Primary Button</a>
<a class="btn btn-secondary">Default Button</a>