.scroll-to-top {
    width: 52px;
    height: 52px;
    border: 1px solid var(--color-border);
    border-radius: 50%;
    background: #ffffff;
    box-shadow: var(--shadow-card);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0;
    position: fixed;
    right: var(--space-5);
    bottom: var(--space-5);
    z-index: 45;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    cursor: pointer;
    transform: translateY(12px);
    transition: opacity 180ms ease, visibility 180ms ease, transform 180ms ease, box-shadow 180ms ease;
}

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

.scroll-to-top:hover,
.scroll-to-top:focus-visible {
    box-shadow: var(--shadow-blue);
    transform: translateY(-2px);
}

.scroll-to-top[data-tooltip]::after {
    position: absolute;
    right: calc(100% + var(--space-2));
    top: 50%;
    padding: var(--space-1) var(--space-2);
    border: 1px solid rgba(255, 255, 255, 0.18);
    border-radius: var(--radius-sm);
    background: var(--color-dark);
    box-shadow: 0 8px 20px rgba(3, 15, 29, 0.28);
    color: #ffffff;
    content: attr(data-tooltip);
    font-size: 12px;
    font-weight: 700;
    line-height: 1.35;
    opacity: 0;
    pointer-events: none;
    transform: translate(4px, -50%);
    transition: opacity 140ms ease, transform 140ms ease;
    white-space: nowrap;
    z-index: 1;
}

.scroll-to-top[data-tooltip]:hover::after,
.scroll-to-top[data-tooltip]:focus-visible::after {
    opacity: 1;
    transform: translate(0, -50%);
}

.scroll-to-top__icon {
    width: 34px;
    height: 34px;
    background: var(--color-primary);
    display: block;
    mask: url('../../svg/arrow-up-circle.svg') center / contain no-repeat;
    -webkit-mask: url('../../svg/arrow-up-circle.svg') center / contain no-repeat;
}

.mobile-menu-open .scroll-to-top {
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
}

@media (max-width: 560px) {
    .scroll-to-top {
        width: 46px;
        height: 46px;
        right: var(--space-4);
        bottom: var(--space-4);
    }

    .scroll-to-top__icon {
        width: 30px;
        height: 30px;
    }
}

@media (prefers-reduced-motion: reduce) {
    .scroll-to-top {
        transition-duration: 0.01ms;
    }
}