/* 美化顶部导航栏 */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: linear-gradient(135deg, #2563eb, #1e40af);
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    padding: 12px 5%;
    position: fixed;
    top: 0;
    left: 0;
    width: 90%;
    z-index: 1000;
    color: white;
    font-family: 'Inter', 'SF Pro Display', -apple-system, sans-serif;
    transition: all 0.3s ease;
}

.header h1 {
    margin: 0;
    font-size: 1.8rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 10px;
}

.header h1::before {
    content: '';
    display: inline-block;
    width: 32px;
    height: 32px;
    background: url('../images/logo.svg') no-repeat center;
    background-size: contain;
}

/* 主导航样式 */
.main-nav ul {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
    gap: 5px;
}

.main-nav a {
    text-decoration: none;
    color: white;
    font-weight: 500;
    padding: 8px 16px;
    border-radius: 20px;
    transition: all 0.3s ease;
}

.main-nav a:hover {
    background: rgba(255,255,255,0.2);
    transform: translateY(-2px);
}

.main-nav a.active {
    background: rgba(255,255,255,0.3);
    font-weight: 600;
}

/* 语言切换器 */
.language-switcher {
    display: flex;
    gap: 8px;
}

.language-switcher button {
    background: rgba(255,255,255,0.1);
    border: none;
    color: white;
    padding: 6px 12px;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9rem;
}

.language-switcher button:hover {
    background: rgba(255,255,255,0.3);
}

.language-switcher button.active {
    background: white;
    color: #2563eb;
    font-weight: 600;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .header {
        flex-direction: column;
        gap: 12px;
        padding: 12px;
        width: 100%;
    }
    
    .main-nav ul {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .main-nav a {
        padding: 6px 12px;
        font-size: 0.9rem;
    }
}

@media (max-width: 480px) {
    .header h1 {
        font-size: 1.5rem;
    }
    
    .main-nav ul {
        flex-direction: column;
        align-items: center;
    }
    
    .main-nav li {
        width: 100%;
        text-align: center;
    }
}