header {
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(0,0,0,0.35);
    backdrop-filter: blur(10px);
    transition: background 0.3s;
}

header.scrolled {
    background: rgba(0,0,0,0.9);
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 40px;
}

.navbar-brand {
    color: #4fc3f7;
    font-size: 20px;
    display: inline-flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
}

.navbar-logo {
    width: 28px;
    height: 28px;
    object-fit: contain;
    filter: drop-shadow(0 0 8px rgba(79, 195, 247, 0.6));
}

.navbar-nombre {
    font-family: 'Orbitron', sans-serif;
    letter-spacing: 1px;
}

nav ul {
    list-style: none;
    display: flex;
    gap: 25px;
}

nav a {
    text-decoration: none;
    color: #4fc3f7;
    font-size: 14px;
    transition: 0.3s;
    padding-bottom: 3px;
}

nav a:hover,
nav a.active {
    color: white;
    text-shadow: 0 0 10px #4fc3f7;
}

nav a.active {
    border-bottom: 2px solid #4fc3f7;
}

.menu-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    background: none;
    border: none;
    padding: 4px;
}

.menu-toggle span {
    width: 25px;
    height: 3px;
    background: #4fc3f7;
    margin: 4px 0;
    transition: transform 0.3s ease, opacity 0.3s ease;
}

.menu-toggle[aria-expanded="true"] span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.menu-toggle[aria-expanded="true"] span:nth-child(2) {
    opacity: 0;
}

.menu-toggle[aria-expanded="true"] span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

@media (max-width: 768px) {
    nav ul {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        width: 100%;
        background: rgba(0, 0, 0, 0.95);
        flex-direction: column;
        padding: 18px 30px;
        gap: 18px;
        opacity: 0;
        transform: translateY(-8px);
        pointer-events: none;
        transition: opacity 0.25s ease, transform 0.25s ease;
    }

    nav ul.active {
        display: flex;
        opacity: 1;
        transform: translateY(0);
        pointer-events: auto;
    }

    .menu-toggle {
        display: flex;
    }
}