/* ── BACK TO TOP ─────────────────────────────────────────── */
#btt {
    position: fixed;
    bottom: 24px;
    right: 24px;
    width: 40px;
    height: 40px;
    background: var(--blue);
    color: #fff;
    border: none;
    border-radius: 10px;
    font-size: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--sh-md);
    cursor: pointer;
    opacity: 0;
    transform: translateY(10px);
    transition: all 0.25s;
    z-index: 999;
}

#btt.show {
    opacity: 1;
    transform: translateY(0);
}

#btt:hover {
    background: var(--blue-mid);
}