.header {
    background-color: #fff;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 100;
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
}

.nav-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.lang-switch {
    display: flex;
    gap: 4px;
}

.lang-btn {
    background: none;
    border: 1px solid #2c3e50;
    color: #2c3e50;
    padding: 4px 8px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.875rem;
}

.lang-btn:hover {
    background-color: #e9ecef;
}

.lang-btn[data-lang="zh"] {
    font-size: 1rem;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: #2c3e50;
    text-decoration: none;
}

.nav-links {
    display: flex;
    gap: 20px;
}

.nav-link {
    color: #2c3e50;
    text-decoration: none;
    padding: 8px 16px;
    border-radius: 4px;
    transition: background-color 0.3s;
}

.nav-link:hover,
.nav-link.active {
    background-color: #e9ecef;
}

.menu-toggle {
    display: none;
    font-size: 1.5rem;
    background: none;
    border: none;
    color: #2c3e50;
    cursor: pointer;
    padding: 5px;
}

@media screen and (max-width: 768px) {
    .menu-toggle {
        display: block;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        flex-direction: column;
        background-color: #fff;
        padding: 1rem;
        box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    }

    .nav-links.active {
        display: flex;
    }

    .nav-link {
        width: 100%;
        text-align: center;
        padding: 12px;
    }
}