/* Botão global: voltar ao topo */
.voltar-topo {
    position: fixed;
    right: 24px;
    bottom: 24px;
    z-index: 120;
    width: 52px;
    height: 52px;
    display: grid;
    place-items: center;
    padding: 0;
    border: 1px solid rgba(255, 255, 255, .28);
    border-radius: 999px;
    background: #AF3527;
    color: #FFF;
    box-shadow: 0 14px 36px rgba(102, 45, 33, .28);
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transform: translateY(10px);
    transition: opacity .2s ease, transform .2s ease, background-color .2s ease, visibility .2s ease;
}

.voltar-topo.is-visible {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transform: translateY(0);
}

.voltar-topo:hover,
.voltar-topo:focus-visible {
    background: #E94E3A;
}

.voltar-topo:focus-visible {
    outline: 3px solid rgba(233, 78, 58, .35);
    outline-offset: 3px;
}

.voltar-topo svg {
    width: 24px;
    height: 24px;
    display: block;
    fill: none;
    stroke: currentColor;
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
}

@media (max-width: 640px) {
    .voltar-topo {
        right: 16px;
        bottom: 16px;
        width: 48px;
        height: 48px;
    }
}

@media (prefers-reduced-motion: reduce) {
    .voltar-topo {
        transition: none;
    }
}