.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;

    margin: 16px;
    border-radius: 16px;
    padding: 1rem 2rem;

    background: rgba(255, 255, 255, 0.18);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);

    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.15);
    z-index: 1000;
    transition: top 1s; /* animação suave */
}

/* NAV */
.header .nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* LOGO */
.logotipo {
    position: relative;
    height: 48px;
}

.logotipo img {
    height: 48px;
    display: block;
    user-select: none;
    pointer-events: none;
}

.logo-base {
    opacity: 1;
    transition: opacity 0.4s ease;
}

.logo-hover {
    position: absolute;
    inset: 0;
    opacity: 0;
    transition: opacity 0.4s ease;
}

.logotipo:hover .logo-base {
    opacity: 0;
}

.logotipo:hover .logo-hover {
    opacity: 1;
}

/* MENU */
.menu {
    list-style: none;
    display: flex;
    gap: 40px;
    margin: 0;
    padding: 0;
}

.menu li a {
    color: #fff;
    text-decoration: none;
    font-weight: 500;
    position: relative;
    transition: color 0.3s ease;
}

.menu li a::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: -6px;
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: width 0.3s ease;
}

.menu li a:hover {
    color: var(--accent);
}

.menu li a:hover::after {
    width: 100%;
}




/* MOBILE (sem hamburger) */
@media (max-width: 768px) {

    .header .nav {
        flex-direction: column;
        gap: 12px;
    }

    .menu {
        justify-content: center;
        gap: 30px;
        margin: 8px;
        flex-wrap: wrap;
    }
}