.page-loader {
    position: fixed;
    inset: 0;
    background: rgba(15, 23, 42, 0.85);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    backdrop-filter: blur(6px);
}

.page-loader.hidden {
    opacity: 0;
    pointer-events: none;
    transition: opacity .3s ease;
}

.spinner {
    width: 48px;
    height: 48px;
    border: 4px solid rgba(255,255,255,.2);
    border-top-color: #38bdf8;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* animación de entrada del contenido */
.fade-in {
    animation: fadeIn .4s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(8px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}