:root {
    --loader-color: #2563eb; /* Un bleu moderne type Tailwind */
    --loader-bg: rgba(255, 255, 255, 0.7); /* Fond blanc translucide */
}

#loader-overlay {
    position: fixed;
    inset: 0; /* Remplace top, left, right, bottom: 0 */
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: var(--loader-bg);
    backdrop-filter: blur(3px); /* Flou d'arrière-plan */
    -webkit-backdrop-filter: blur(8px);
    z-index: 10000;
    transition: opacity 0.4s ease, visibility 0.4s;

    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease-in-out; /* Animation douce */
}

/* Classes pour le contrôle JS */
.loader-hidden {
    opacity: 0;
    visibility: hidden;
}

.loader-visible {
    opacity: 1 !important;
    visibility: visible !important;
}

.loader-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
}

/* Le Spinner Minimaliste */
.spinner-ring {
    width: 40px;
    height: 40px;
    border: 3px solid rgba(0, 0, 0, 0.1);
    border-radius: 50%;
    border-top-color: var(--loader-color);
    animation: spin 0.8s cubic-bezier(0.6, 0.2, 0.4, 0.8) infinite;
}

.loader-text {
    font-family: 'Inter', -apple-system, sans-serif;
    font-size: 0.9rem;
    font-weight: 500;
    color: #1f2937;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

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