main {
    flex: 1 0 auto;
}

a:hover {
    color: #45a29e;
    text-decoration: underline;
}

.navbar-dark .navbar-nav .nav-link.active {
    font-weight: bold;
    color: #45a29e;
}

.section-title {
    font-weight: 700;
    margin-bottom: 1.5rem;
    border-bottom: 1px solid #8000ff3f;
    padding-bottom: 1.0rem;
}

/* ================= BACK TO TOP ================= */
#backToTop {
    position: fixed;
    bottom: 28px;
    right: 28px;
    width: 48px;
    height: 48px;
    border-radius: 14px;

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

    background: rgba(20, 20, 24, 0.75);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);

    border: 1px solid rgba(127, 0, 255, 0.35);
    color: #ffffff;
    cursor: pointer;

    opacity: 0;
    visibility: hidden;
    transform: translateY(10px) scale(0.95);

    transition: all .28s ease;
    z-index: 999;
}

/* quando aparece */
#backToTop.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0) scale(1);
}

/* hover premium */
#backToTop:hover {
    transform: translateY(-3px) scale(1.05);
    border-color: rgba(127, 0, 255, 0.7);
    box-shadow:
        0 10px 30px rgba(127, 0, 255, 0.25),
        0 0 12px rgba(127, 0, 255, 0.25) inset;
}

/* acessibilidade */
#backToTop:focus-visible {
    outline: 2px solid #7f00ff;
    outline-offset: 3px;
}

/* ================= MOBILE ================= */
@media (max-width: 480px) {
    #backToTop {
        bottom: 20px;
        right: 20px;
        width: 44px;
        height: 44px;
        border-radius: 12px;
    }
}