/* ===== 全局重置 ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    background-color: #F4F6F9;
    color: #1E2A3A;
    line-height: 1.7;
}

a {
    text-decoration: none;
    color: inherit;
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== 头部 ===== */
.header {
    background-color: #1E2A3A;
    color: white;
    padding: 16px 0;
    box-shadow: 0 4px 12px rgba(0,0,0,0.04);
    position: sticky;
    top: 0;
    z-index: 200;
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo-area {
    display: flex;
    align-items: baseline;
    gap: 8px;
}

.logo-area h1 {
    font-size: 28px;
    font-weight: 700;
    letter-spacing: 0.5px;
    background: linear-gradient(135deg, #FFFFFF 0%, #E0E6ED 100%);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.logo-area span {
    font-size: 14px;
    opacity: 0.75;
    font-weight: 400;
    color: #B0C4DE;
}

.nav {
    display: flex;
    align-items: center;
    gap: 28px;
}

.nav a {
    color: #EDF2F7;
    font-size: 15px;
    font-weight: 500;
    transition: color 0.2s;
}

.nav a:hover {
    color: #F39C12;
}

.mega-menu-trigger {
    background: rgba(255,255,255,0.12);
    padding: 8px 20px;
    border-radius: 30px;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    transition: background 0.2s, box-shadow 0.2s;
    border: 1px solid rgba(255,255,255,0.05);
    backdrop-filter: blur(4px);
}

.mega-menu-trigger:hover {
    background: rgba(255,255,255,0.2);
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
}

.header-divider {
    height: 2px;
    background: linear-gradient(90deg, transparent, #F39C12, transparent);
    opacity: 0.3;
}

/* ===== Mega Menu 开关（纯 CSS） ===== */
#megaMenuToggle {
    display: none;
}

#megaMenuToggle:checked ~ .mega-menu-panel {
    display: block;
}
#megaMenuToggle:checked ~ .menu-overlay {
    display: block;
}

/* ===== Mega Menu 面板 ===== */
.mega-menu-panel {
    position: fixed;
    top: 72px;
    left: 0;
    width: 100%;
    background: white;
    box-shadow: 0 20px 40px rgba(0,0,0,0.12);
    z-index: 199;
    display: none;
    border-top: 1px solid #E2E8F0;
    border-bottom: 1px solid #E2E8F0;
    max-height: calc(100vh - 72px);
    overflow-y: auto;
}

.mega-menu-inner {
    max-width: 1280px;
    margin: 0 auto;
    padding: 30px 24px;
    display: flex;
    gap: 40px;
}

/* 左侧一级分类 */
.mega-categories {
    flex: 0 0 200px;
    border-right: 1px solid #E2E8F0;
    padding-right: 20px;
    max-height: 500px;
    overflow-y: auto;
}

.mega-category-item {
    padding: 10px 16px;
    margin-bottom: 4px;
    border-radius: 8px;
    font-weight: 500;
    color: #2C3E50;
    cursor: pointer;
    transition: all 0.15s;
    display: flex;
    align-items: center;
    gap: 10px;
}

.mega-category-item:hover {
    background: #F8F9FA;
    color: #F39C12;
}

.mega-category-item.active {
    background: #FDEBD0;
    color: #D35400;
    font-weight: 600;
}

/* ===== 右侧二级分类面板（由 JS 控制显示/隐藏） ===== */
.mega-subcategories {
    flex: 1;
    position: relative;
}

.subcat-panel {
    display: none;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px 20px;
    align-content: start;
    width: 100%;
}

/* 默认第一个面板显示（JS 也会控制，这里做兜底） */
.subcat-panel:first-child {
    display: grid;
}

.subcategory-group h4 {
    font-size: 16px;
    font-weight: 700;
    color: #1E2A3A;
    margin-bottom: 16px;
    padding-bottom: 6px;
    border-bottom: 2px solid #F39C12;
    display: inline-block;
}

.subcategory-group ul {
    list-style: none;
}

.subcategory-group li {
    margin-bottom: 12px;
}

.subcategory-group a {
    color: #4A5A6A;
    font-size: 14px;
    transition: all 0.15s;
}

.subcategory-group a:hover {
    color: #F39C12;
    padding-left: 4px;
}

.view-more-link {
    margin-top: 12px;
    font-size: 13px;
    grid-column: 1 / -1;
}

.view-more-link a {
    color: #F39C12;
    font-weight: 500;
}

/* 遮罩 */
.menu-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.2);
    backdrop-filter: blur(2px);
    z-index: 198;
    display: none;
    cursor: pointer;
}

/* ===== 响应式 ===== */
@media (max-width: 900px) {
    .mega-menu-inner {
        flex-direction: column;
    }
    .mega-categories {
        flex: auto;
        border-right: none;
        border-bottom: 1px solid #E2E8F0;
        max-height: 200px;
        display: flex;
        flex-wrap: wrap;
        gap: 8px;
        padding-right: 0;
        padding-bottom: 12px;
    }
    .mega-category-item {
        width: calc(50% - 8px);
    }
    .subcat-panel {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .header-content {
        flex-wrap: wrap;
        gap: 12px;
    }
    .nav {
        flex-wrap: wrap;
        gap: 16px;
    }
}