/* ===== 导航栏 ===== */
nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    padding: 1.5rem 2rem;
    z-index: 100;
}

.nav-content {
    max-width: 1400px;
    margin: 0 auto;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    margin-bottom: 1rem;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    font-size: 1rem;
    transition: all 0.3s;
    position: relative;
}

.nav-links a:hover {
    color: white;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
    transition: width 0.3s;
}

.nav-links a:hover::after {
    width: 100%;
}