/* ============================================================
           头部布局
           ============================================================ */
        .header-main {
            padding: 12px 0;
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 24px;
            min-height: 88px;
        }
        .header-main .logo-section {
            display: flex; align-items: center; gap: 14px; flex-shrink: 0;
        }
        .header-main .logo-icon {
            width: 64px; height: 64px;
            object-fit: contain; cursor: pointer; display: block;
        }
        .header-main .logo-text h1 {
            color: var(--white); font-size: 30px; font-weight: 600;letter-spacing: 0.8px;
            margin-bottom: 3px; cursor: pointer; line-height: 1.2;
            white-space: nowrap;
        }
        .header-main .logo-text p {
            color: rgba(255, 255, 255, 0.8); font-size: 6px;
            letter-spacing: 0.35px; line-height: 1.2; white-space: nowrap;
        }
        .header-right-stack {
            display: flex; flex-direction: column; justify-content: center;
            gap: 6px; height: 64px; flex-shrink: 0;
        }
        .header-search-row {
            display: flex; justify-content: flex-end; align-items: center;
            height: 28px;
        }
        .nav-search-btn {
            background: rgba(255, 255, 255, 0.12);
            border: 1px solid rgba(255, 255, 255, 0.2);
            color: #fff; height: 28px; padding: 0 14px;
            border-radius: 14px; display: flex; align-items: center;
            gap: 6px; cursor: pointer; transition: all 0.3s ease;
            font-size: 13px; font-family: inherit; white-space: nowrap;
            flex-shrink: 0;
        }
        .nav-search-btn:hover {
            background: rgba(255, 255, 255, 0.25); transform: scale(1.03);
        }
        .nav-search-btn svg {
            width: 15px; height: 15px; fill: none; stroke: #fff;
            stroke-width: 2.2; stroke-linecap: round; stroke-linejoin: round;
            flex-shrink: 0;
        }
        .header-nav-row {
            display: flex; justify-content: flex-end; align-items: center;
            height: 30px; position: relative;
        }
        .header-nav-row nav { display: flex; align-items: center; height: 100%; }
        .nav-menu { display: flex; gap: 2px; align-items: center; height: 100%; }
        .nav-menu > li {
            position: relative; height: 100%; display: flex; align-items: center;
        }
        .nav-menu > li > a {
            padding: 0 14px; color: var(--white); font-size: 14px;
            display: flex; align-items: center; gap: 4px;
            border-radius: 4px; transition: background 0.25s ease;
            white-space: nowrap; height: 100%; line-height: 1;
        }
        .nav-menu > li > a:hover,
        .nav-menu > li > a.active { background: rgba(255, 255, 255, 0.15); }
        .nav-menu > li.has-submenu > a::after {
            content: ''; display: inline-block; width: 0; height: 0;
            border-left: 4px solid transparent;
            border-right: 4px solid transparent;
            border-top: 5px solid rgba(255, 255, 255, 0.7);
            margin-left: 5px; transition: transform 0.25s ease;
            vertical-align: middle;
        }
        .nav-menu > li.has-submenu:hover > a::after {
            transform: rotate(180deg); border-top-color: #fff;
        }
        .submenu {
            position: absolute; top: 100%; left: 0;
            min-width: 220px; background: #fff;
            border-radius: 0 0 8px 8px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.18);
            padding: 8px 0; opacity: 0; visibility: hidden;
            transform: translateY(8px);
            transition: all 0.28s cubic-bezier(0.4, 0, 0.2, 1);
            z-index: 1100; list-style: none; margin: 0;
            border-top: 3px solid var(--accent-red);
        }
        .nav-menu > li.has-submenu:hover > .submenu {
            opacity: 1; visibility: visible; transform: translateY(0);
        }
        .submenu li { margin: 0; }
        .submenu li a {
            display: block; padding: 11px 22px; color: var(--text-dark);
            font-size: 14px; transition: all 0.2s ease;
            border-left: 3px solid transparent;
        }
        .submenu li a:hover {
            background: var(--light-blue); color: var(--primary-blue);
            border-left-color: var(--accent-red); padding-left: 26px;
        }

        /* ============================================================
           移动端适配
           ============================================================ */
        @media (max-width: 768px) {
            .header-main { padding: 10px 0; gap: 10px; min-height: 66px; }
            .header-main .logo-icon { width: 44px; height: 44px; }
            .header-main .logo-text h1 { font-size: 14px; }
            .header-main .logo-text p { display: none; }
            .header-right-stack {
                height: 44px; gap: 8px; flex-direction: row; align-items: center;
            }
            .header-search-row { height: 100%; order: 1; }
            .nav-search-btn {
                height: 34px; padding: 0 10px; font-size: 12px;
                gap: 4px; border-radius: 17px;
            }
            .nav-search-btn svg { width: 14px; height: 14px; }
            .header-nav-row { height: 100%; order: 2; }
            .header-nav-row nav { height: 100%; position: relative; }
            .nav-menu {
                display: none; position: absolute;
                top: calc(100% + 12px); right: 0; left: auto;
                min-width: 240px; max-height: calc(100vh - 130px);
                overflow-y: auto;
                background: linear-gradient(135deg, var(--primary-blue) 0%, var(--secondary-blue) 100%);
                flex-direction: column; gap: 0; padding: 10px 0;
                box-shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
                z-index: 999; border-radius: 8px; height: auto;
            }
            body.mobile-nav-open .nav-menu { display: flex; }
            .nav-menu > li { width: 100%; height: auto; }
            .nav-menu > li > a {
                padding: 14px 20px; font-size: 15px;
                justify-content: space-between;
                border-bottom: 1px solid rgba(255, 255, 255, 0.1);
                border-radius: 0; height: auto;
            }
            .nav-menu > li:last-child > a { border-bottom: none; }
            .nav-menu > li.has-submenu > a::after { margin-left: auto; }
            .submenu {
                position: static; opacity: 1; visibility: visible;
                transform: none; box-shadow: none;
                background: rgba(0, 0, 0, 0.2); border-radius: 0;
                border-top: none; padding: 0; max-height: 0;
                overflow: hidden;
                transition: max-height 0.35s ease, padding 0.35s ease;
            }
            .nav-menu > li.has-submenu.active > .submenu {
                max-height: 500px; padding: 6px 0;
            }
            .submenu li a {
                padding: 11px 20px 11px 40px;
                color: rgba(255, 255, 255, 0.85); font-size: 14px;
                border-bottom: 1px solid rgba(255, 255, 255, 0.05);
            }
            .submenu li a:hover {
                background: rgba(255, 255, 255, 0.1); color: #fff;
                border-left-color: var(--accent-red); padding-left: 44px;
            }
            .mobile-menu-btn {
                display: flex; flex-direction: column; justify-content: center;
                gap: 5px; width: 38px; height: 38px;
                background: rgba(255, 255, 255, 0.1); border: none;
                cursor: pointer; padding: 8px; border-radius: 4px;
                transition: background 0.3s; flex-shrink: 0;
            }
            .mobile-menu-btn:hover { background: rgba(255, 255, 255, 0.2); }
            .mobile-menu-btn span {
                display: block; width: 100%; height: 2px;
                background: #fff; border-radius: 2px;
                transition: all 0.3s ease;
            }
            body.mobile-nav-open .mobile-menu-btn span:nth-child(1) {
                transform: translateY(7px) rotate(45deg);
            }
            body.mobile-nav-open .mobile-menu-btn span:nth-child(2) { opacity: 0; }
            body.mobile-nav-open .mobile-menu-btn span:nth-child(3) {
                transform: translateY(-7px) rotate(-45deg);
            }
        }
        @media (max-width: 480px) {
            .header-main .logo-text h1 {
                font-size: 12px; max-width: 150px;
                overflow: hidden; text-overflow: ellipsis;
            }
            .header-right-stack { gap: 6px; }
            .nav-search-btn {
                height: 30px; padding: 0 8px; font-size: 11px;
            }
            .nav-search-btn svg { width: 13px; height: 13px; }
            .mobile-menu-btn { width: 34px; height: 34px; gap: 4px; }
            .nav-menu { min-width: 200px; max-height: calc(100vh - 110px); }
        }

        /* ============================================================
           搜索蒙版层（原生表单提交）
           ============================================================ */
        .search-overlay {
            position: fixed; top: 0; left: 0;
            width: 100%; height: 100%;
            background: rgba(0, 0, 0, 0.6);
            backdrop-filter: blur(4px);
            z-index: 2000;
            display: flex; align-items: center; justify-content: center;
            visibility: hidden; opacity: 0;
            transition: all 0.3s ease;
            padding: 20px; box-sizing: border-box;
        }
        .search-overlay.active { visibility: visible; opacity: 1; }
        .search-overlay-content {
            background: #fff;
            width: 90%; max-width: 600px;
            border-radius: 16px;
            padding: 28px 28px 26px;
            box-shadow: 0 25px 50px rgba(0, 0, 0, 0.3);
            transform: scale(0.95);
            transition: transform 0.3s ease;
            position: relative;
        }
        .search-overlay.active .search-overlay-content { transform: scale(1); }
        .search-overlay-close {
            position: absolute; top: 14px; right: 18px;
            background: none; border: none; font-size: 26px;
            color: #999; cursor: pointer; line-height: 1;
            transition: color 0.2s; padding: 0 5px;
        }
        .search-overlay-close:hover { color: #c41e3a; }
        .search-overlay-content h3 {
            color: #003366; font-size: 20px;
            margin-bottom: 16px; text-align: center; font-weight: 600;
        }
        .search-input-wrapper {
            display: flex; gap: 10px;
            background: #f0f4fa; border-radius: 50px;
            padding: 4px 4px 4px 20px;
            border: 2px solid transparent;
            transition: border-color 0.2s, box-shadow 0.2s;
        }
        .search-input-wrapper:focus-within {
            border-color: #0055a5;
            box-shadow: 0 0 0 4px rgba(0, 85, 165, 0.15);
        }
        .search-input-wrapper input {
            flex: 1; border: none; background: transparent;
            padding: 12px 0; font-size: 15px;
            outline: none; color: #333; min-width: 0;
        }
        .search-input-wrapper input::placeholder { color: #999; }
        .search-input-wrapper button {
            background: linear-gradient(135deg, #003366, #0055a5);
            color: #fff; border: none; border-radius: 50px;
            padding: 10px 26px; font-size: 15px; font-weight: 500;
            cursor: pointer;
            transition: background 0.2s, transform 0.1s;
            white-space: nowrap;
            font-family: inherit;
        }
        .search-input-wrapper button:hover {
            background: linear-gradient(135deg, #004488, #0066cc);
        }
        .search-input-wrapper button:active { transform: scale(0.97); }
        .search-hot-tags {
            margin-top: 14px; display: flex; flex-wrap: wrap;
            gap: 8px; justify-content: center;
        }
        .search-hot-tags a {
            font-size: 12px; color: #666;
            padding: 4px 12px; background: #f0f4fa;
            border-radius: 50px; cursor: pointer;
            transition: all 0.2s;
            text-decoration: none;
            display: inline-block;
        }
        .search-hot-tags a:hover { background: #003366; color: #fff; }

        .header-main nav { display: flex; align-items: center; }