Generated by SassMeister.com.

SassMeister-input.scss

// ----
// libsass (v3.2.4)
// ----

.c-nav {
  position: relative;

  &:before {
    content: 'Menu';
    display: inline-block;
    padding: 1rem;
  }
  
  // less obvious what's going here actually:
  &:focus &,
  &:hover & {
    // also this is repeated
    &:before {
      background-color:grey;
    }  
  }
  
}

SassMeister-output.css

.c-nav {
  position: relative;
}

.c-nav:before {
  content: 'Menu';
  display: inline-block;
  padding: 1rem;
}

.c-nav:focus .c-nav:before,
.c-nav:hover .c-nav:before {
  background-color: grey;
}