.msf-slider {
    position: relative;
    max-width: 600px;
    margin: 1em auto;
    height: 80px;
    overflow: hidden;
    background: #222;
    color: #fff;
    border-radius: 8px;
}
.msf-track { position: relative; width: 100%; height: 100%; }
.msf-slide {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5em;
    opacity: 0;
    transition: opacity .6s ease;
}
.msf-slide-active { opacity: 1; }