* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Noto Sans SC', sans-serif;
    background: #f5f5f5;
    color: #333;
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ========== Header ========== */
.header {
    background: white;
    border-bottom: 1px solid #e0e0e0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}

.header-content {
    display: flex;
    align-items: center;
    height: 60px;
    gap: 2rem;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: #2563eb;
    text-decoration: none;
    white-space: nowrap;
    flex-shrink: 0;
}

/* ========== 导航 ========== */
.main-nav {
    display: flex;
    align-items: center;
    gap: 0.25rem;
    flex: 1;
}

.nav-link {
    display: inline-flex;
    align-items: center;
    padding: 0.5rem 0.75rem;
    color: #333;
    text-decoration: none;
    font-size: 0.95rem;
    border-radius: 6px;
    transition: background 0.15s;
    white-space: nowrap;
}

.nav-link:hover {
    background: #f0f4ff;
    color: #2563eb;
}

.nav-arrow {
    margin-left: 0.25rem;
    font-size: 0.75rem;
    color: #999;
}

.nav-item {
    position: relative;
}

.nav-dropdown {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background: white;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    min-width: 160px;
    padding: 0.5rem 0;
    z-index: 200;
}

.nav-item:hover .nav-dropdown {
    display: block;
}

.nav-dropdown a {
    display: block;
    padding: 0.5rem 1rem;
    color: #333;
    text-decoration: none;
    font-size: 0.9rem;
    transition: background 0.15s;
}

.nav-dropdown a:hover {
    background: #f0f4ff;
    color: #2563eb;
}

/* ========== Header 搜索 + 操作区 ========== */
.header-actions {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-shrink: 0;
}

.header-search {
    display: flex;
    align-items: center;
    border: 1px solid #e0e0e0;
    border-radius: 20px;
    overflow: hidden;
    background: #f9f9f9;
    transition: border-color 0.15s;
}

.header-search:focus-within {
    border-color: #2563eb;
    background: #fff;
}

.header-search .search-input {
    border: none;
    outline: none;
    padding: 0.4rem 0.75rem;
    font-size: 0.9rem;
    background: transparent;
    width: 180px;
    font-family: inherit;
}

.header-search .search-btn {
    border: none;
    background: #2563eb;
    color: white;
    cursor: pointer;
    padding: 0.5rem 0.7rem;
    font-size: 0.9rem;
    line-height: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.2s;
}

.header-search .search-btn:hover {
    background: #1d4ed8;
}

.search-toggle {
    display: none;
    border: none;
    background: transparent;
    cursor: pointer;
    font-size: 1.2rem;
    padding: 0.4rem;
}

/* ========== 汉堡菜单 ========== */
.hamburger {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 32px;
    height: 32px;
    border: none;
    background: transparent;
    cursor: pointer;
    padding: 4px;
}

.hamburger span {
    display: block;
    width: 100%;
    height: 2px;
    background: #333;
    border-radius: 1px;
    transition: transform 0.2s, opacity 0.2s;
}

.hamburger.active span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* ========== 移动端搜索栏 ========== */
.mobile-search {
    display: none;
    background: white;
    border-top: 1px solid #f0f0f0;
    padding: 0.75rem 0;
}

.mobile-search.active {
    display: block;
}

.mobile-search form {
    display: flex;
    gap: 0.5rem;
}

.mobile-search .search-input {
    flex: 1;
    border: 1px solid #e0e0e0;
    border-radius: 6px;
    padding: 0.5rem 0.75rem;
    font-size: 0.9rem;
    font-family: inherit;
    outline: none;
}

.mobile-search .search-input:focus {
    border-color: #2563eb;
}

.mobile-search .search-btn {
    border: none;
    background: #2563eb;
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9rem;
    font-family: inherit;
}

/* ========== 面包屑 ========== */
.breadcrumb {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
    color: #666;
}

.breadcrumb a {
    color: #2563eb;
    text-decoration: none;
}

.breadcrumb a:hover {
    text-decoration: underline;
}

.breadcrumb-separator {
    color: #ccc;
}

/* ========== Footer ========== */
.site-footer {
    background: #1a1a2e;
    color: #ccc;
    padding: 3rem 0 0;
    margin-top: 2rem;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: 2rem;
    padding-bottom: 2rem;
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.footer-logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: #fff;
    text-decoration: none;
}

.footer-desc {
    font-size: 0.85rem;
    color: #999;
    line-height: 1.8;
}

.footer-col {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.footer-col-title {
    font-size: 0.95rem;
    font-weight: 500;
    color: #fff;
    margin-bottom: 0.25rem;
}

.footer-col a {
    color: #aaa;
    text-decoration: none;
    font-size: 0.85rem;
    transition: color 0.15s;
}

.footer-col a:hover {
    color: #fff;
}

.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.1);
    padding: 1rem 0;
    text-align: center;
    font-size: 0.8rem;
    color: #777;
}

.footer-bottom a {
    color: #888;
    text-decoration: none;
}

.footer-bottom a:hover {
    color: #ccc;
}

/* ========== 响应式 ========== */
@media (max-width: 768px) {
    .header-content {
        gap: 0.5rem;
    }

    .main-nav {
        display: none;
        position: absolute;
        top: 60px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 0.5rem 0;
        border-top: 1px solid #f0f0f0;
        box-shadow: 0 4px 12px rgba(0,0,0,0.1);
        gap: 0;
    }

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

    .nav-link {
        padding: 0.75rem 1.25rem;
        border-radius: 0;
        width: 100%;
    }

    .nav-item {
        width: 100%;
    }

    .nav-dropdown {
        position: static;
        border: none;
        box-shadow: none;
        border-radius: 0;
        padding: 0;
        display: none;
        background: #f9f9f9;
    }

    .nav-item.open .nav-dropdown {
        display: block;
    }

    .nav-dropdown a {
        padding-left: 2.5rem;
    }

    .header-search {
        display: none;
    }

    .search-toggle,
    .hamburger {
        display: flex;
    }

    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 1.5rem;
    }

    .footer-brand {
        grid-column: 1 / -1;
    }
}

@media (max-width: 480px) {
    .footer-grid {
        grid-template-columns: 1fr;
    }
}