Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.3.0.rc.1)
// Compass (v0.13.alpha.10)
// ----

%my-placeholder {
    background:black;
    padding:20px;
    position:relative;
    color:red;
    
    &:before {
        background:purple;
        content:'I was here before you.';
        padding:20px;
        position:absolute;
        top:0;
        right:100%;
    }
    &:after {
        background:pink;
        content:'I come after you.';
        padding:20px;
        position:absolute;
        top:0;
        left:100%;
    }
}
 
@media all and (max-width: 699px) and (min-width: 520px), (min-width: 1151px) {
    .can-i-extend {
        @extend %my-placeholder;
    }
}

SassMeister-output.css

You may not @extend an outer selector from within @media.
You may only @extend selectors within the same directive.
From "@extend %my-placeholder" on line 27 of /app/lib/sassmeister.rb.