/* Scroll-to-top button */

.z-stt-container {
    /* Es un <button>: reseteamos estilos de UA para que se vea idéntico. */
    border: 0;
    padding: 0;
    -webkit-appearance: none;
    appearance: none;
    position: fixed;
    bottom: 40px;
    right: 40px;
    width: 55px;
    height: 55px;
    cursor: pointer;
    z-index: 10000;
    opacity: 0;
    visibility: hidden;
    transform: translateY(15px);
    transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.3s ease, box-shadow 0.3s ease;
    background-color: var(--zander-black);
    border-radius: 50%;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
}

.z-stt-container.z-stt-visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.z-stt-svg-content {
    position: absolute;
    top: 0; left: 0;
    z-index: 1;
}

.z-stt-circle-bg {
    fill: none;
    stroke: rgba(255, 255, 255, 0.1);
    stroke-width: 4;
}

.z-stt-circle-progress {
    fill: none;
    stroke: var(--zander-yellow);
    stroke-width: 5;
    stroke-linecap: round;
    transition: stroke-dashoffset 10ms linear;
}

.z-stt-arrow {
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2;
    color: var(--zander-yellow);
    transition: transform 0.3s ease, color 0.3s ease;
}

.z-stt-arrow svg {
    width: 26px;
    height: 26px;
}

.z-stt-container:hover {
    transform: scale(1.1);
    box-shadow: 0 14px 32px rgba(0, 0, 0, 0.3);
}

.z-stt-container:hover .z-stt-arrow {
    color: var(--zander-white-soft);
    transform: translateY(-2px);
}

@media (max-width: 768px) {
    .z-stt-container {
        bottom: 25px;
        right: 25px;
        width: 50px;
        height: 50px;
    }
}