/* ═══════════ Heavy Duty Truck Parts — Global Styles ═══════════ */
:root {
  --navy: #16233a;
  --navy-2: #1e3050;
  --orange: #f07d00;
  --orange-2: #d96d00;
  --gray-bg: #f4f6f9;
  --border: #dde3ec;
  --text: #2b3442;
  --text-2: #6b7686;
  --radius: 6px;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: "Segoe UI", "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif; color: var(--text); background: var(--gray-bg); font-size: 14px; }
a { color: inherit; text-decoration: none; }
a:hover { color: var(--orange); }
.container { max-width: 1360px; margin: 0 auto; padding: 0 16px; }

/* ── 顶部工具条 ── */
.utility-bar { background: var(--navy); color: #b9c4d6; font-size: 12px; }
.utility-inner { display: flex; justify-content: space-between; align-items: center; height: 34px; }
.utility-links { display: flex; align-items: center; gap: 18px; }
.utility-links a:hover { color: #fff; }
.lang-switch { display: flex; gap: 2px; margin-left: 8px; }
.lang-switch button { background: transparent; border: 1px solid #3a4c68; color: #b9c4d6; padding: 2px 8px; border-radius: 3px; cursor: pointer; font-size: 11px; }
.lang-switch button.on { background: var(--orange); border-color: var(--orange); color: #fff; }

/* ── 主头部 ── */
.site-header { background: #fff; border-bottom: 3px solid var(--orange); }
.header-inner { display: flex; align-items: center; gap: 32px; padding: 16px; }
.logo { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }
.logo-icon { font-size: 34px; }
.logo-text { font-size: 20px; font-weight: 600; color: var(--navy); line-height: 1.1; }
.logo-text strong { color: var(--orange); }
.logo-text small { display: block; font-size: 10px; font-weight: 400; color: var(--text-2); letter-spacing: .5px; }

/* OEM 搜索块 */
.search-block { flex: 1; max-width: 720px; position: relative; }
.search-tabs { display: flex; gap: 0; margin-bottom: -1px; position: relative; z-index: 2; }
.search-tabs button { border: 1px solid var(--border); border-bottom: none; background: var(--gray-bg); padding: 5px 14px; font-size: 12px; border-radius: 5px 5px 0 0; cursor: pointer; color: var(--text-2); }
.search-tabs button.on { background: var(--navy); color: #fff; border-color: var(--navy); font-weight: 600; }
.search-row { display: flex; border: 2px solid var(--navy); border-radius: 0 var(--radius) var(--radius) var(--radius); overflow: hidden; }
.search-row input { flex: 1; border: none; padding: 12px 14px; font-size: 14px; outline: none; }
.search-btn { background: var(--orange); color: #fff; border: none; padding: 0 28px; font-size: 15px; font-weight: 600; cursor: pointer; }
.search-btn:hover { background: var(--orange-2); }
.search-hint { font-size: 11px; color: var(--text-2); margin-top: 5px; }
.search-suggest { position: absolute; top: 100%; left: 0; right: 0; background: #fff; border: 1px solid var(--border); border-radius: var(--radius); box-shadow: 0 8px 24px rgba(0,0,0,.12); z-index: 50; max-height: 340px; overflow: auto; }
.suggest-item { display: grid; grid-template-columns: 150px 1fr auto; gap: 10px; padding: 10px 14px; border-bottom: 1px solid var(--gray-bg); align-items: center; }
.suggest-item:hover { background: #fff8f0; }
.suggest-oem { font-weight: 700; color: var(--navy); font-family: Consolas, monospace; }
.suggest-name { color: var(--text); }
.suggest-brands { font-size: 11px; color: var(--text-2); }

.header-actions { display: flex; gap: 10px; flex-shrink: 0; }
.action-btn { display: inline-flex; align-items: center; gap: 6px; border: 1px solid var(--border); padding: 10px 16px; border-radius: var(--radius); font-weight: 600; color: var(--navy); }
.action-btn.rfq { background: var(--navy); color: #fff; border-color: var(--navy); }
.action-btn.rfq:hover { background: var(--navy-2); color: #fff; }
.badge { background: var(--orange); border-radius: 10px; padding: 1px 7px; font-size: 11px; }

/* ── 主导航 ── */
.main-nav { background: var(--navy-2); position: relative; z-index: 40; }
.nav-inner { display: flex; align-items: stretch; }
.nav-item { position: relative; display: flex; }
.nav-link { display: flex; align-items: center; padding: 13px 16px; color: #dde5f0; font-weight: 600; font-size: 13.5px; background: none; border: none; cursor: pointer; font-family: inherit; white-space: nowrap; }
.nav-link:hover, .nav-item:hover > .nav-link { background: var(--orange); color: #fff; }
.all-cat-btn { background: var(--orange); color: #fff; min-width: 200px; }
.all-cat-btn:hover { background: var(--orange-2) !important; }

/* Mega Menu 三级 */
.mega-menu { position: absolute; top: 100%; left: 0; display: flex; background: #fff; color: var(--text); box-shadow: 0 10px 30px rgba(0,0,0,.18); border: 1px solid var(--border); min-height: 380px; width: 920px; }
.mega-l1 { width: 230px; background: var(--gray-bg); border-right: 1px solid var(--border); padding: 8px 0; }
.mega-l1-item { display: flex; justify-content: space-between; align-items: center; padding: 0 16px; }
.mega-l1-item a { flex: 1; padding: 11px 0; font-weight: 600; font-size: 13px; }
.mega-l1-item a small { color: var(--text-2); font-weight: 400; margin-left: 4px; }
.mega-l1-item.on, .mega-l1-item:hover { background: #fff; box-shadow: inset 3px 0 0 var(--orange); }
.mega-l1-item.on a { color: var(--orange); }
.mega-l1-item .arrow { color: var(--text-2); }
.mega-l23 { flex: 1; padding: 18px 24px; }
.mega-l1-title { font-size: 15px; border-bottom: 2px solid var(--orange); display: inline-block; padding-bottom: 6px; margin-bottom: 14px; }
.mega-l1-title a { color: var(--navy); }
.mega-l2-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px 28px; }
.mega-l2-col h4 { font-size: 13px; margin-bottom: 6px; }
.mega-l2-col h4 a { color: var(--navy); font-weight: 700; }
.mega-l2-col h4 small { color: var(--text-2); font-weight: 400; }
.mega-l2-col ul { list-style: none; }
.mega-l2-col li a { display: block; font-size: 12.5px; color: var(--text-2); padding: 3px 0; }
.mega-l2-col li a:hover { color: var(--orange); }

/* 下拉（品牌 / 车型） */
.dropdown { position: absolute; top: 100%; left: 0; background: #fff; color: var(--text); display: flex; gap: 0; box-shadow: 0 10px 30px rgba(0,0,0,.18); border: 1px solid var(--border); padding: 14px 0; max-height: 430px; overflow: auto; }
.brand-dd { min-width: 420px; }
.model-dd { min-width: 720px; flex-wrap: wrap; }
.dd-col { min-width: 190px; padding: 0 20px; border-right: 1px solid var(--gray-bg); }
.dd-col:last-child { border-right: none; }
.dd-col h5 { font-size: 12px; color: var(--orange); text-transform: uppercase; letter-spacing: .5px; margin: 6px 0 8px; }
.dd-col a { display: block; padding: 5px 0; font-size: 13px; color: var(--text); }
.dd-col a:hover { color: var(--orange); }

/* ── 面包屑 ── */
.breadcrumb { list-style: none; display: flex; flex-wrap: wrap; gap: 6px; padding: 12px 0 0; font-size: 12.5px; color: var(--text-2); }
.breadcrumb li { display: flex; gap: 6px; align-items: center; }
.breadcrumb a { color: var(--navy); }
.breadcrumb .sep { color: var(--border); }

/* ── 主体布局 ── */
.main-layout { display: grid; grid-template-columns: 250px 1fr; gap: 22px; padding-top: 14px; padding-bottom: 40px; }

/* 左侧分类树 */
.sidebar { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; align-self: start; position: sticky; top: 12px; max-height: calc(100vh - 24px); overflow: auto; }
.side-title { font-size: 14px; color: var(--navy); border-bottom: 2px solid var(--orange); padding-bottom: 7px; margin-bottom: 10px; }
.side-title:not(:first-child) { margin-top: 22px; }
.cat-tree, .cat-tree ul { list-style: none; }
.tree-l1, .tree-l2 { display: flex; align-items: center; flex-wrap: wrap; gap: 2px 6px; padding: 5px 0; cursor: pointer; }
.tree-l1 a { font-weight: 600; font-size: 13px; }
.tree-l1 small { color: var(--text-2); font-size: 10.5px; flex-basis: 100%; padding-left: 20px; margin-top: -2px; }
.cat-tree ul { padding-left: 18px; }
.tree-l2 a { font-size: 12.5px; color: var(--text-2); font-weight: 600; }
.tree-l3 { padding: 2px 0 2px 24px; }
.tree-l3 a { font-size: 12px; color: var(--text-2); }
.tree-l3 a.on, .tree-l3 a:hover { color: var(--orange); font-weight: 600; }
.twisty { display: inline-block; width: 14px; color: var(--text-2); font-size: 10px; transition: transform .15s; }
.twisty.open { transform: rotate(90deg); color: var(--orange); }
.brand-filter { display: flex; flex-direction: column; gap: 6px; }
.brand-check { font-size: 12.5px; color: var(--text); display: flex; gap: 7px; align-items: center; cursor: pointer; }
.brand-check input { accent-color: var(--orange); }

/* 车型查找器 Hero */
.fitment-finder { background: linear-gradient(115deg, var(--navy) 0%, var(--navy-2) 70%, #274069 100%); color: #fff; border-radius: var(--radius); padding: 34px 32px 30px; margin-bottom: 18px; }
.fitment-finder h1 { font-size: 25px; line-height: 1.3; margin-bottom: 8px; }
.hero-sub { color: #b9c4d6; margin-bottom: 20px; }
.fitment-row { display: flex; gap: 10px; flex-wrap: wrap; }
.fitment-row select { flex: 1; min-width: 170px; padding: 12px; border-radius: var(--radius); border: none; font-size: 14px; background: #fff; }
.fitment-btn { background: var(--orange); color: #fff; border: none; padding: 0 30px; border-radius: var(--radius); font-size: 15px; font-weight: 700; cursor: pointer; min-height: 46px; }
.fitment-btn:hover { background: var(--orange-2); }

/* 筛选条件 */
.active-filters { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 10px 14px; margin-bottom: 14px; font-size: 12.5px; }
.filter-tag { background: #fff3e3; border: 1px solid var(--orange); color: var(--orange-2); border-radius: 14px; padding: 3px 10px; display: inline-flex; gap: 6px; align-items: center; }
.filter-tag button { background: none; border: none; color: var(--orange-2); cursor: pointer; font-size: 14px; line-height: 1; }
.clear-all { background: none; border: none; color: var(--text-2); text-decoration: underline; cursor: pointer; }

/* 产品卡片 */
.result-head h2 { font-size: 19px; color: var(--navy); margin-bottom: 12px; }
.result-head small { color: var(--text-2); font-weight: 400; font-size: 13px; }
.product-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 14px; }
.product-card { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); display: flex; gap: 12px; padding: 14px; transition: box-shadow .15s; }
.product-card:hover { box-shadow: 0 6px 18px rgba(22,35,58,.1); border-color: var(--orange); }
.pc-img { width: 74px; height: 74px; background: var(--gray-bg); border-radius: var(--radius); display: flex; align-items: center; justify-content: center; font-size: 32px; flex-shrink: 0; }
.pc-name { font-size: 13.5px; line-height: 1.35; margin-bottom: 3px; }
.pc-name a { color: var(--navy); }
.pc-name a:hover { color: var(--orange); }
.pc-cat { font-size: 11px; color: var(--text-2); margin-bottom: 6px; }
.pc-oem { font-size: 11.5px; display: grid; grid-template-columns: auto 1fr; gap: 2px 8px; margin-bottom: 8px; }
.pc-oem dt { color: var(--text-2); }
.pc-oem dd { color: var(--text); }
.oem-num { font-family: Consolas, monospace; font-weight: 700; color: var(--navy) !important; background: #eef2f8; border-radius: 3px; padding: 0 5px; justify-self: start; }
.pc-foot { display: flex; justify-content: space-between; align-items: center; margin-bottom: 8px; }
.pc-price { font-size: 17px; font-weight: 700; color: var(--orange-2); }
.pc-price small { font-size: 10px; color: var(--text-2); font-weight: 400; }
.pc-stock { font-size: 11px; color: #1a8f3c; background: #e8f7ec; padding: 2px 8px; border-radius: 10px; }
.pc-stock.req { color: #9a6a00; background: #fdf3d8; }
.pc-btn { width: 100%; background: var(--navy); color: #fff; border: none; padding: 8px; border-radius: var(--radius); font-weight: 600; cursor: pointer; }
.pc-btn:hover { background: var(--orange); }
.no-result { background: #fff; border: 1px dashed var(--border); border-radius: var(--radius); padding: 30px; text-align: center; color: var(--text-2); }

/* SEO 文本块 */
.seo-block { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 24px 28px; margin-top: 22px; }
.seo-block h2 { font-size: 17px; color: var(--navy); margin-bottom: 10px; }
.seo-block p { font-size: 13px; line-height: 1.75; color: var(--text-2); margin-bottom: 8px; }

/* ── 页脚 Sitemap ── */
.site-footer { background: var(--navy); color: #b9c4d6; padding: 36px 0 24px; }
.footer-title { color: #fff; font-size: 16px; margin-bottom: 18px; }
.footer-grid { display: grid; grid-template-columns: repeat(6, 1fr); gap: 24px; margin-bottom: 26px; }
.footer-col h3 { font-size: 13px; margin-bottom: 10px; }
.footer-col h3 a { color: #fff; }
.footer-col h4 { font-size: 12px; margin: 10px 0 4px; }
.footer-col h4 a { color: var(--orange); font-weight: 600; }
.f-link { display: block; font-size: 11.5px; color: #93a2b8; padding: 2px 0; }
.f-link:hover { color: #fff; }
.footer-brands { border-top: 1px solid #2c3e5c; padding-top: 18px; }
.footer-brands h3 { color: #fff; font-size: 13px; margin-bottom: 8px; }
.footer-brands .f-link { display: inline-block; margin-right: 16px; }
.footer-brands .f-link.model { color: #75859c; }
.copyright { margin-top: 24px; padding-top: 14px; border-top: 1px solid #2c3e5c; font-size: 11px; color: #75859c; }

/* 响应式 */
@media (max-width: 1000px) {
  .main-layout { grid-template-columns: 1fr; }
  .sidebar { position: static; max-height: none; }
  .mega-menu { width: 100%; }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
  .header-inner { flex-wrap: wrap; }
  .search-block { order: 3; max-width: none; width: 100%; }
}

/* ═══════════ About Us 页面 ═══════════ */
.about-hero { background: linear-gradient(115deg, var(--navy) 0%, var(--navy-2) 70%, #274069 100%); color: #fff; padding: 52px 0 46px; }
.about-hero h1 { font-size: 30px; line-height: 1.25; max-width: 760px; margin-bottom: 10px; }
.about-hero .hero-sub { color: #b9c4d6; font-size: 15px; max-width: 720px; }
.about-hero .hero-tag { display: inline-block; background: rgba(240,125,0,.18); border: 1px solid var(--orange); color: #ffb25e; font-size: 11.5px; letter-spacing: 1px; text-transform: uppercase; border-radius: 3px; padding: 4px 10px; margin-bottom: 16px; }

.about-wrap { max-width: 1000px; margin: 0 auto; padding: 0 16px 50px; }
.about-sec { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 30px 34px; margin-top: 22px; }
.about-sec h2 { font-size: 20px; color: var(--navy); margin-bottom: 12px; }
.about-sec h2 .accent { color: var(--orange); }
.about-sec p { font-size: 14px; line-height: 1.8; color: #49545f; margin-bottom: 10px; }
.about-sec p strong { color: var(--navy); }

.value-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(270px, 1fr)); gap: 14px; margin-top: 16px; }
.value-card { border: 1px solid var(--border); border-radius: var(--radius); padding: 18px 20px; background: var(--gray-bg); transition: border-color .15s, box-shadow .15s; }
.value-card:hover { border-color: var(--orange); box-shadow: 0 6px 16px rgba(22,35,58,.08); }
.value-card .v-icon { font-size: 24px; }
.value-card h3 { font-size: 14.5px; color: var(--navy); margin: 8px 0 6px; }
.value-card p { font-size: 12.5px; line-height: 1.65; color: var(--text-2); margin: 0; }

.qc-steps { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 14px; margin-top: 16px; counter-reset: qc; }
.qc-step { position: relative; border: 1px solid var(--border); border-radius: var(--radius); padding: 20px 20px 16px 64px; background: #fff; }
.qc-step::before { counter-increment: qc; content: counter(qc); position: absolute; left: 18px; top: 18px; width: 32px; height: 32px; border-radius: 50%; background: var(--orange); color: #fff; font-weight: 700; font-size: 16px; display: flex; align-items: center; justify-content: center; }
.qc-step h3 { font-size: 14px; color: var(--navy); margin-bottom: 6px; }
.qc-step p { font-size: 12.5px; line-height: 1.65; color: var(--text-2); margin: 0; }
.qc-badge { display: inline-flex; align-items: center; gap: 8px; background: #eef2f8; border: 1px solid #c8d4e6; color: var(--navy); border-radius: var(--radius); padding: 8px 14px; font-weight: 700; font-size: 13px; margin-top: 14px; }

.serve-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 14px; margin-top: 16px; }
.serve-card { border-top: 3px solid var(--orange); background: var(--gray-bg); border-radius: 0 0 var(--radius) var(--radius); padding: 18px 20px; }
.serve-card h3 { font-size: 14.5px; color: var(--navy); margin-bottom: 8px; }
.serve-card p { font-size: 12.5px; line-height: 1.7; color: var(--text-2); margin: 0; }

.commit-list { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 12px 24px; margin-top: 14px; list-style: none; }
.commit-list li { display: flex; gap: 10px; font-size: 13.5px; line-height: 1.6; color: #49545f; }
.commit-list .c-icon { color: var(--orange); font-weight: 700; flex-shrink: 0; }
.commit-list strong { color: var(--navy); }

.about-cta { background: linear-gradient(115deg, var(--orange) 0%, var(--orange-2) 100%); color: #fff; border-radius: var(--radius); padding: 34px 34px; margin-top: 22px; display: flex; align-items: center; justify-content: space-between; gap: 24px; flex-wrap: wrap; }
.about-cta h2 { font-size: 21px; margin-bottom: 6px; }
.about-cta p { color: rgba(255,255,255,.9); font-size: 13.5px; margin: 0; max-width: 560px; }
.about-cta .cta-btn { background: var(--navy); color: #fff; padding: 14px 30px; border-radius: var(--radius); font-weight: 700; font-size: 15px; white-space: nowrap; }
.about-cta .cta-btn:hover { background: #0f1828; color: #fff; }