/* ==========================================================================
   Scroll to Top Button — Front-end Styles
   ========================================================================== */

#stb-btn {
    position: fixed;
    bottom: 1.5rem;
    right: 1.5rem; /* overridden by inline CSS from PHP settings */
    z-index: 9999;

    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 3rem;
    height: 3rem;
    border: none;
    border-radius: 50%;
    cursor: pointer;

    background-color: var(--stb-bg, #333);
    color: var(--stb-color, #fff);
    font-size: 1.25rem;
    line-height: 1;

    opacity: 0;
    transform: translateY(0.5rem);
    transition: opacity 0.25s ease, transform 0.25s ease;

    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.25);
}

#stb-btn[hidden] {
    display: none;
}

#stb-btn.stb-visible {
    opacity: 1;
    transform: translateY(0);
}

#stb-btn:hover,
#stb-btn:focus-visible {
    filter: brightness(1.15);
    outline: 2px solid var(--stb-bg, #333);
    outline-offset: 3px;
}