@media (min-width: 768px) {
    .side-nav {
    position: fixed;
    left: 20px;
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    height: 70vh;
    z-index: 20;
    }

    .side-nav span {
    width: 6px;
    height: 6px;
    background: #a5a5a55d;
    opacity: 0.4;
    
    margin: 0 auto;
    transition: transform 0.4s ease, background 1s ease, opacity 1s ease;
    }

    .side-nav span.active {
    transform: scale(1.4);
    background-color: purple;
    opacity: 1;
    }

    .side-nav .line {
    position: absolute;
    left: 50%;
    width: 1px;
    background-color: purple;
    transform: translateX(-50%);
    opacity: 0.3; /* base légère */
    border-radius: 2px;
    transition: background 0.5s ease-in-out, opacity 0.5s ease-in-out, height 0.3s ease-in-out;
    }
    .side-nav .line.active {
    opacity: 1;
    }
}