/* 极简清晰网站头部样式 - 与category_page统一设计 */
.site-header {
    background: linear-gradient(135deg, #f8f9fa 0%, #ffffff 100%);
    color: #1a1a1a;
    padding: 2.5rem 0;
    border-bottom: 1px solid #f0f0f0;
    position: relative;
    font-family: 'Noto Sans CJK SC', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', sans-serif;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.04);
}

.site-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #6b7c93, #8fa3b8, #6b7c93);
    border-radius: 0 0 2px 2px;
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
    z-index: 1;
}

.site-branding {
    flex: 1;
}

.site-title {
    font-size: 2rem;
    font-weight: 300;
    margin: 0;
    letter-spacing: 0.02em;
    line-height: 1.3;
    color: #1a1a1a;
    position: relative;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}


.site-title a {
    color: #1a1a1a;
    text-decoration: none;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
}

.site-title a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, #6b7c93, #8fa3b8);
    transition: width 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    border-radius: 1px;
}

.site-title a:hover {
    color: #6b7c93;
    transform: translateY(-1px);
}

.site-title a:hover::after {
    width: 100%;
}

.site-subtitle {
    font-size: 1rem;
    margin: 1.2rem 0 0 0;
    color: #4a4a4a;
    font-weight: 400;
    letter-spacing: 0.01em;
    line-height: 1.5;
    transition: color 0.3s ease;
}

.main-navigation {
    flex: 1;
    display: flex;
    justify-content: flex-end;
}

.nav-menu {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
    gap: 3rem;
    align-items: center;
}

.nav-item {
    position: relative;
}

.nav-link {
    color: #4a4a4a;
    text-decoration: none;
    font-weight: 400;
    font-size: 1.1rem;
    padding: 0.8rem 1.2rem;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    letter-spacing: 0.01em;
    border-radius: 8px;
    background: transparent;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, #6b7c93, #8fa3b8);
    transition: width 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    border-radius: 1px;
}

.nav-link:hover::after {
    width: 80%;
}

.nav-link:hover {
    color: #6b7c93;
    background: linear-gradient(135deg, rgba(107, 124, 147, 0.05) 0%, rgba(143, 163, 184, 0.05) 100%);
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(107, 124, 147, 0.1);
}

.external-link {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
}

.external-icon {
    font-size: 0.7rem;
    opacity: 0.7;
    color: #6b7c93;
    transition: all 0.3s ease;
}

.nav-link:hover .external-icon {
    opacity: 1;
    color: #8fa3b8;
    transform: translate(2px, -2px);
}

/* Mobile Navigation */
.mobile-nav-toggle {
    display: none;
    background: linear-gradient(135deg, #f8f9fa 0%, #ffffff 100%);
    border: 2px solid #e8e8e8;
    color: #6b7c93;
    font-size: 1.2rem;
    cursor: pointer;
    padding: 0.8rem 1.2rem;
    border-radius: 8px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
}

.mobile-nav-toggle:hover {
    color: #8fa3b8;
    border-color: #6b7c93;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(107, 124, 147, 0.15);
}

.mobile-nav-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: linear-gradient(135deg, #ffffff 0%, #f8f9fa 100%);
    border-top: 1px solid #e8e8e8;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
    z-index: 1000;
    max-height: 80vh;
    overflow-y: auto;
    border-radius: 0 0 12px 12px;
}

.mobile-nav-menu.active {
    display: block;
}

.mobile-nav-menu ul {
    list-style: none;
    margin: 0;
    padding: 0.5rem 0;
}

.mobile-nav-menu li {
    border-bottom: 1px solid #f0f0f0;
}

.mobile-nav-menu li:last-child {
    border-bottom: none;
}

.mobile-nav-menu a {
    display: block;
    padding: 1rem 1.5rem;
    color: #4a4a4a;
    text-decoration: none;
    font-weight: 400;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    letter-spacing: 0.01em;
    font-size: 1rem;
    position: relative;
}

.mobile-nav-menu a:hover {
    background: linear-gradient(135deg, rgba(107, 124, 147, 0.08) 0%, rgba(143, 163, 184, 0.08) 100%);
    color: #6b7c93;
    transform: translateX(4px);
}

.mobile-nav-menu a::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 0;
    background: linear-gradient(90deg, #6b7c93, #8fa3b8);
    transition: width 0.3s ease;
}

.mobile-nav-menu a:hover::before {
    width: 3px;
}

.mobile-nav-menu .external-icon {
    float: right;
    margin-top: 0.2rem;
}

/* 移动端菜单遮罩层 */
.mobile-nav-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.3);
    z-index: 999;
}

.mobile-nav-overlay.active {
    display: block;
}

/* 响应式设计 - 与category_page统一 */
@media (max-width: 768px) {
    .site-header {
        padding: 2rem 0;
    }
    
    .header-container {
        padding: 0 1.5rem;
        flex-direction: column;
        gap: 1.5rem;
    }
    
    .site-branding {
        text-align: center;
        order: 1;
    }
    
    .site-title {
        font-size: 1.8rem;
    }
    
    .site-subtitle {
        font-size: 0.95rem;
        margin-top: 1rem;
    }
    
    .main-navigation {
        order: 2;
        width: 100%;
        justify-content: center;
    }
    
    .nav-menu {
        display: none;
    }
    
    .mobile-nav-toggle {
        display: block;
    }
    
    .mobile-nav-menu {
        display: none;
    }
}

@media (max-width: 480px) {
    .site-header {
        padding: 1.5rem 0;
    }
    
    .header-container {
        padding: 0 1rem;
    }
    
    .site-title {
        font-size: 1.6rem;
    }
    
    .site-subtitle {
        font-size: 0.9rem;
    }
    
    .mobile-nav-toggle {
        padding: 0.6rem 1rem;
        font-size: 1.1rem;
    }
}