@each $tuple in
    'wf-100' 100%, 'wf-80' 80%, 'wf-20' 20%, 'wf-66' 66.66%,
    'wf-50' 50%, 'wf-33' 33.33%, 'wf-25' 25%, 'wf-75' 75% {
    .#{nth($tuple, 1)} {
        width: #{nth($tuple, 2)};
    }
}

.spacer {
    padding: 5px;
}

.resizable {
    resize: both;
    overflow: auto;
}