/* =========================================================
   SCROLL TO TOP
   ========================================================= */

.scroll-to-top {
    position: fixed;

    right: 28px;
    bottom: 28px;

    z-index: 950;

    width: 48px;
    height: 48px;

    display: flex;
    align-items: center;
    justify-content: center;

    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);

    background:
        rgba(17, 16, 26, 0.82);

    color: var(--color-text);

    font-family: var(--font-mono);
    font-size: 18px;

    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);

    box-shadow:
        0 10px 30px rgba(0, 0, 0, 0.25);

    opacity: 0;
    visibility: hidden;

    transform:
        translateY(15px);

    pointer-events: none;

    transition:
        opacity var(--transition-base),
        visibility var(--transition-base),
        transform var(--transition-base),
        border-color var(--transition-fast),
        background-color var(--transition-fast),
        box-shadow var(--transition-fast);
}


.scroll-to-top.is-visible {
    opacity: 1;
    visibility: visible;

    transform: translateY(0);

    pointer-events: auto;
}


.scroll-to-top:hover {
    border-color:
        var(--color-primary);

    background:
        var(--color-surface-elevated);

    box-shadow:
        var(--shadow-primary-strong);

    color:
        var(--color-primary-soft);
}


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


/* =========================================================
   MOBILE
   ========================================================= */

@media (max-width: 600px) {

    .scroll-to-top {
        right: 18px;
        bottom: 18px;

        width: 44px;
        height: 44px;
    }
}