.btn {
    position: relative;
    padding: 1rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    color: white;
    background: none;
    /*border: 2px solid #4164a6;*/
    border-radius: 6px;
    cursor: pointer;
    overflow: hidden;
    transition: all 0.3s ease;
}

.liquid {
    background: linear-gradient(#4164a6 0 0) no-repeat calc(200% - var(--p, 0%))
    100% / 200% var(--p, 0.2em);
    transition: 0.3s var(--t, 0s),
    background-position 0.3s calc(0.3s - var(--t, 0s));
}

.liquid:hover {
    --p: 100%;
    --t: 0.3s;
    color: #fff;
}