/**
 * To Top Button
 * Style minimaliste et accessible
 */
.to-top-button {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--wp--preset--color--contrast, #000);
    color: var(--wp--preset--color--base, #fff);
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s;
    z-index: 999;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    display: flex;
    align-items: center;
    justify-content: center;
}

.to-top-button svg {
    display: block;
}

.to-top-button.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.to-top-button:hover {
    background: var(--wp--preset--color--contrast, #333);
    transform: translateY(-3px);
}

.to-top-button:focus {
    outline: 2px solid var(--wp--preset--color--contrast, #000);
    outline-offset: 3px;
}

/* Responsive */
@media (max-width: 768px) {
    .to-top-button {
        bottom: 1rem;
        right: 1rem;
        width: 45px;
        height: 45px;
    }
}

/* Accessibilité */
@media (prefers-reduced-motion: reduce) {
    .to-top-button {
        transition: opacity 0.1s, visibility 0.1s;
        transform: none !important;
    }
}