#chargement {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    z-index: 300;
    display: flex;
    align-items: center;
    background: #055;
    opacity: 0;
    pointer-events: none;
    animation: chargement 1.3s;
}

@keyframes chargement {
    0% {
        opacity: 1;
    }
    80% {
        opacity: 1;
    }
}

#sinus {
    background: url(img/sinus.svg);
    min-width: 200%;
    height: 220px;
    animation: onde 1.5s linear;
}

@keyframes onde {
    0% {
        transform: translateX(-400px);
    }
}

#plus-volt,
#moins-volt {
    color: #ef6;
    position: absolute;
    top: 50%;
    left: 10px;
    margin-top: -140px;
    font-size: .8em;
}

#moins-volt {
    margin-top: 120px;
}