header {
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(10px);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    padding: 1rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo img {
    height: 40px;
    width: auto;
    transition: transform var(--transition-speed);
}

.logo:hover img {
    transform: scale(1.1);
}

nav {
    display: flex;
    gap: 2rem;
}

nav a {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    font-size: 1rem;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    transition: all var(--transition-speed);
    position: relative;
    overflow: hidden;
}

nav a::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient);
    transition: width var(--transition-speed);
}

nav a:hover {
    color: var(--accent-hover);
    background: rgba(59, 130, 246, 0.1);
}

nav a:hover::before {
    width: 100%;
}

nav a {
    animation: fadeInUp 0.5s ease-out forwards;
    opacity: 0;
}

nav a:nth-child(1) { animation-delay: 0.1s; }
nav a:nth-child(2) { animation-delay: 0.2s; }
nav a:nth-child(3) { animation-delay: 0.3s; }