.back-to-top {
    position: fixed;
    right: 24px;
    bottom: 24px;
    z-index: 1100;
    width: 44px;
    height: 44px;
    padding: 0;
    border: none;
    border-radius: 12px;
    background: var(--primary, #0f62fe);
    color: #fff;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 14px rgba(15, 23, 42, 0.18);
    opacity: 0;
    visibility: hidden;
    transform: translateY(12px);
    transition: opacity 0.2s ease, visibility 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
    pointer-events: none;
}

.back-to-top.is-visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
    pointer-events: auto;
}

.back-to-top:hover {
    box-shadow: 0 6px 20px rgba(15, 23, 42, 0.22);
    filter: brightness(1.05);
}

.back-to-top:active {
    transform: translateY(1px);
}

.back-to-top.is-visible:active {
    transform: translateY(1px);
}

.back-to-top svg {
    width: 20px;
    height: 20px;
    stroke: currentColor;
    fill: none;
    stroke-width: 2.5;
    stroke-linecap: round;
    stroke-linejoin: round;
}

@media (max-width: 768px) {
    .back-to-top {
        right: 16px;
        bottom: 16px;
        width: 40px;
        height: 40px;
    }
}