/**
 * Scroll-to-top — стеклянная (glass) кнопка «Наверх» в правом нижнем углу.
 * Используется на Premium Landings (rooms/uslugi/zabota/all-inclusive/pravila).
 * Параллельно существует inline-вариант на main/index-new/couples/gallery-new/rooms-info/booking-success.
 */

.scroll-top-tz {
    position: fixed;
    z-index: 1000;
    bottom: 28px;
    right: 32px;
    width: 46px;
    height: 46px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid rgba(255, 255, 255, 0.40);
    padding: 0;
    margin: 0;
    cursor: pointer;
    line-height: 1;
    box-sizing: border-box;
    font-size: 0;
    color: #fff;

    /* Стекло (teal — гармонирует с lime Wi-Fi бейджем) */
    background:
        radial-gradient(circle at 30% 25%, rgba(180, 230, 225, 0.30) 0%, transparent 55%),
        linear-gradient(150deg, rgba(20, 140, 140, 0.82) 0%, rgba(13, 110, 110, 0.78) 45%, rgba(9, 85, 85, 0.85) 100%);
    backdrop-filter: blur(14px) saturate(160%);
    -webkit-backdrop-filter: blur(14px) saturate(160%);
    box-shadow:
        inset 0 2px 3px rgba(255, 255, 255, 0.45),
        inset 0 -3px 5px rgba(0, 0, 0, 0.25),
        0 6px 16px rgba(13, 110, 110, 0.40),
        0 2px 6px rgba(0, 0, 0, 0.18);

    opacity: 0;
    visibility: hidden;
    transition: opacity 0.25s ease, visibility 0.25s ease, transform 0.2s ease, box-shadow 0.25s ease;
}

.scroll-top-tz svg {
    width: 22px;
    height: 22px;
    display: block;
    flex-shrink: 0;
    pointer-events: none;
}

.scroll-top-tz.show {
    opacity: 1;
    visibility: visible;
}

.scroll-top-tz:hover {
    transform: translateY(-2px);
    box-shadow:
        inset 0 2px 3px rgba(255, 255, 255, 0.55),
        inset 0 -3px 5px rgba(0, 0, 0, 0.28),
        0 10px 22px rgba(13, 110, 110, 0.55),
        0 4px 10px rgba(0, 0, 0, 0.22);
}

.scroll-top-tz:active {
    transform: translateY(0);
}

.scroll-top-tz:focus-visible {
    outline: 2px solid var(--amber, #d4a843);
    outline-offset: 4px;
}

/* Tablet portrait — соосно с .silver-chat-btn (right:32) */
@media (max-width: 1024px) {
    .scroll-top-tz {
        bottom: 24px;
        right: 32px;
        width: 44px;
        height: 44px;
    }
    .scroll-top-tz svg {
        width: 20px;
        height: 20px;
    }
}

/* Mobile — соосно с .silver-chat-btn на мобиле (right:30) */
@media (max-width: 768px) {
    .scroll-top-tz {
        bottom: 20px;
        right: 30px;
        width: 42px;
        height: 42px;
    }
    .scroll-top-tz svg {
        width: 20px;
        height: 20px;
    }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
    .scroll-top-tz {
        transition: opacity 0.15s linear, visibility 0.15s linear;
    }
    .scroll-top-tz:hover,
    .scroll-top-tz:active {
        transform: none;
    }
}