/* Topbar modo claro: se activa antes de llegar a #slide4 */
.topbar--light {
    background: rgba(255, 255, 255, 0.92) !important;
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.08) !important;
    transition: background 0.4s ease, border-color 0.4s ease;
}

.topbar--light svg {
    fill: #000 !important;
    transition: fill 0.4s ease;
}

.topbar--light .share-container span {
    color: #000 !important;
    transition: color 0.4s ease;
}

.topbar--light .share-container .line {
    background-color: #000 !important;
    transition: background-color 0.4s ease;
}