.preview {
    display: flex;
    align-items: center;
    align-content: space-around;
}

.preview-result, .preview-input {
    display: inline-block;
    width: 50%;
    padding: 10px;
    margin: 10px;
    position: relative;
}

.preview-input.error {
    border: 1px solid red;
}

.preview-result::before {
    content: "Type your data in and I'll do the work for you!";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(255, 255, 255, 0.8);
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
    animation: pop-out .5s forwards;
}

.preview-result.need-data::before {
    animation: pop-in .5s forwards;
}

/* ------------------------------------- */
/* ------------ Explanation ------------ */
/* ------------------------------------- */

.explanations {
    display: grid;
    grid-template-columns: 50% 50%;
    grid-gap: 20px;
}

.explanation {
    margin: 0;
}