#scroll-top-btn {
    position: fixed;
    bottom: 16px;
    right: 16px;
    width: 36px;
    height: 36px;
    border: 1px solid rgba(15, 118, 110, 0.25);
    border-radius: 10px;
    background: transparent;
    color: #0f766e;
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.5px;
    cursor: pointer;
    box-shadow: none;
    z-index: 9999;
    opacity: 0;
    transform: translateY(8px);
    pointer-events: none;
    transition: opacity 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

#scroll-top-btn.is-visible {
    opacity: 0.6;
    transform: translateY(0);
    pointer-events: auto;
}

#scroll-top-btn:hover {
    opacity: 0.9;
    transform: translateY(-2px);
}

#scroll-top-btn:active {
    transform: translateY(1px);
}

#scroll-top-btn:focus-visible {
    outline: 3px solid rgba(20, 184, 166, 0.35);
    outline-offset: 2px;
}