/* ==========================================================
   广荣环保 官网样式表
   配色：科技蓝主色（深蓝 #0a3d8f + 亮蓝 #0a63c9）+ 深灰页脚
   ========================================================== */
:root {
  --blue-dark: #0a3d8f;
  --blue: #0a63c9;
  --blue-light: #1f8fff;
  --blue-grad: linear-gradient(135deg, #0a3d8f 0%, #0a63c9 60%, #1f8fff 100%);
  --text-main: #333333;
  --text-sub: #666666;
  --text-light: #999999;
  --line: #e5e5e5;
  --bg-gray: #f5f7fa;
  --footer-bg: #22272e;
  --white: #ffffff;
  --radius: 6px;
  --maxw: 1200px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: "Microsoft YaHei", "PingFang SC", "Helvetica Neue", Arial, sans-serif;
  color: var(--text-main);
  font-size: 14px;
  line-height: 1.7;
  background: var(--white);
}

a { text-decoration: none; color: inherit; }
ul, ol { list-style: none; }
img { max-width: 100%; display: block; }

.container { max-width: var(--maxw); margin: 0 auto; padding: 0 15px; }

/* ============ 顶部电话栏 ============ */
.topbar {
  background: var(--blue-grad);
  color: #fff;
  font-size: 13px;
  padding: 7px 0;
}
.topbar .container { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 6px; }
.topbar .hot-words span { margin-right: 18px; opacity: .92; }
.topbar .tel { font-weight: bold; letter-spacing: .5px; }
.topbar .tel b { font-size: 15px; margin-left: 4px; }

/* ============ 导航 ============ */
.header {
  background: var(--white);
  box-shadow: 0 2px 10px rgba(0, 0, 0, .06);
  position: sticky; top: 0; z-index: 999;
}
.header .container { display: flex; align-items: center; justify-content: space-between; height: 78px; }
.logo { display: flex; align-items: center; gap: 12px; }
.logo img { height: 54px; width: auto; }
.logo .logo-text { line-height: 1.2; }
.logo .logo-text .cn { font-size: 22px; font-weight: bold; color: var(--blue-dark); letter-spacing: 1px; }
.logo .logo-text .en { font-size: 11px; color: var(--text-light); letter-spacing: 2px; text-transform: uppercase; }

.nav ul { display: flex; }
.nav ul li { position: relative; }
.nav ul li a {
  display: block; padding: 0 17px; line-height: 78px;
  color: #222; font-size: 15px; font-weight: 500;
  transition: color .2s;
}
.nav ul li a:hover, .nav ul li a.active { color: var(--blue); }
.nav ul li a.active::after {
  content: ""; position: absolute; left: 17px; right: 17px; bottom: 0;
  height: 3px; background: var(--blue-grad); border-radius: 2px 2px 0 0;
}
.nav-toggle { display: none; background: none; border: none; font-size: 24px; color: var(--blue-dark); cursor: pointer; }

/* ============ 轮播 Banner ============ */
.banner { position: relative; height: 520px; overflow: hidden; background: var(--blue-dark); }
.banner .slide {
  position: absolute; inset: 0; opacity: 0; transition: opacity .8s ease; z-index: 1;
  display: flex; align-items: center;
}
.banner .slide.active { opacity: 1; z-index: 2; }
.banner .slide img.bg { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.banner .slide .mask {
  position: absolute; inset: 0;
  background: linear-gradient(90deg, rgba(6, 30, 70, .86) 0%, rgba(10, 61, 143, .68) 45%, rgba(10, 99, 201, .25) 100%);
}
.banner .slide .content { position: relative; z-index: 3; color: #fff; max-width: var(--maxw); margin: 0 auto; padding: 0 15px; width: 100%; }
.banner .slide .content .tag {
  display: inline-block; background: rgba(255,255,255,.16); border: 1px solid rgba(255,255,255,.45);
  padding: 4px 14px; border-radius: 20px; font-size: 13px; margin-bottom: 16px; letter-spacing: 1px;
}
.banner .slide .content h2 { font-size: 42px; font-weight: bold; margin-bottom: 12px; line-height: 1.25; letter-spacing: 1px; }
.banner .slide .content p { font-size: 17px; opacity: .92; max-width: 640px; margin-bottom: 26px; }
.banner .slide .content .btns { display: flex; gap: 14px; }
.banner .slide .content .btn {
  display: inline-block; padding: 11px 30px; border-radius: 4px; font-size: 15px; font-weight: 600;
  background: var(--blue-light); color: #fff; transition: all .2s;
}
.banner .slide .content .btn:hover { background: #fff; color: var(--blue-dark); }
.banner .slide .content .btn.btn-ghost { background: transparent; border: 1px solid #fff; }
.banner .slide .content .btn.btn-ghost:hover { background: #fff; color: var(--blue-dark); }
.banner .dots { position: absolute; bottom: 22px; left: 50%; transform: translateX(-50%); z-index: 5; display: flex; gap: 10px; }
.banner .dots i { width: 34px; height: 4px; border-radius: 2px; background: rgba(255,255,255,.4); cursor: pointer; transition: background .2s; }
.banner .dots i.active { background: #fff; }
.banner .arrow {
  position: absolute; top: 50%; transform: translateY(-50%); z-index: 5;
  width: 44px; height: 44px; border-radius: 50%; border: 1px solid rgba(255,255,255,.5);
  background: rgba(255,255,255,.08); color: #fff; font-size: 20px; cursor: pointer; line-height: 42px; text-align: center;
  transition: background .2s; display: none;
}
.banner:hover .arrow { display: block; }
.banner .arrow:hover { background: rgba(255,255,255,.25); }
.banner .arrow.prev { left: 24px; }
.banner .arrow.next { right: 24px; }

/* ============ 通用板块 ============ */
.section { padding: 60px 0; }
.section.gray { background: var(--bg-gray); }
.section-head { text-align: center; margin-bottom: 42px; }
.section-head .cn { font-size: 30px; font-weight: bold; color: var(--blue-dark); letter-spacing: 2px; }
.section-head .en { font-size: 13px; color: var(--text-light); letter-spacing: 4px; text-transform: uppercase; margin-top: 4px; }
.section-head .line { width: 56px; height: 3px; background: var(--blue-grad); margin: 14px auto 0; border-radius: 2px; }

/* ============ 产品中心 ============ */
.product-wrap { display: flex; gap: 24px; }
.p-cats { width: 220px; flex-shrink: 0; }
.p-cats h3 {
  background: var(--blue-grad); color: #fff; font-size: 16px; font-weight: 600;
  padding: 13px 18px; border-radius: var(--radius) var(--radius) 0 0; letter-spacing: 1px;
}
.p-cats ul li a {
  display: block; padding: 11px 18px; background: #f0f3f8; color: #444; font-size: 14px;
  border-bottom: 1px solid #e3e8f0; transition: all .2s; cursor: pointer;
}
.p-cats ul li a:hover, .p-cats ul li a.active { background: var(--blue); color: #fff; }
.p-grid { flex: 1; display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.p-card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden; transition: all .25s;
}
.p-card:hover { transform: translateY(-4px); box-shadow: 0 10px 24px rgba(10, 61, 143, .12); border-color: var(--blue-light); }
.p-card .pic { height: 185px; background: #fafbfd; display: flex; align-items: center; justify-content: center; overflow: hidden; }
.p-card .pic img { width: 100%; height: 100%; object-fit: cover; transition: transform .3s; }
.p-card:hover .pic img { transform: scale(1.05); }
.p-card .pic.ph {
  background: linear-gradient(135deg, #e8eef7 0%, #d3e0f2 100%);
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 6px;
  color: #8aa3c8; font-size: 12px;
}
.p-card .pic.ph .ph-icon { font-size: 36px; }
.p-card .name { text-align: center; padding: 13px 8px; font-size: 15px; font-weight: 600; color: #222; }
.p-card:hover .name { color: var(--blue); }
.more-btn { text-align: center; margin-top: 34px; }
.more-btn a {
  display: inline-block; padding: 10px 38px; border: 1px solid var(--blue); color: var(--blue);
  border-radius: 30px; font-size: 14px; transition: all .25s;
}
.more-btn a:hover { background: var(--blue); color: #fff; }

/* ============ 关于我们（首页） ============ */
.about-wrap { display: flex; gap: 44px; align-items: center; }
.about-pics { flex: 1; display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.about-pics img { width: 100%; height: 200px; object-fit: cover; border-radius: var(--radius); }
.about-pics img:first-child { grid-row: span 2; height: 100%; }
.about-text { flex: 1.15; }
.about-text h3 { font-size: 24px; color: var(--blue-dark); margin-bottom: 14px; }
.about-text p { color: var(--text-sub); margin-bottom: 12px; text-align: justify; }
.about-text .service-tags { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 18px; }
.about-text .service-tags span {
  background: #eef4fc; color: var(--blue); border: 1px solid #d5e5f9;
  padding: 6px 16px; border-radius: 20px; font-size: 13px;
}
.about-text .about-link { display: inline-block; margin-top: 20px; color: var(--blue); font-weight: 600; }
.about-text .about-link:hover { text-decoration: underline; }

/* ============ 四大优势 ============ */
.adv-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.adv-item {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 30px 22px; text-align: center; transition: all .25s;
}
.adv-item:hover { transform: translateY(-4px); box-shadow: 0 10px 24px rgba(10, 61, 143, .10); border-color: var(--blue-light); }
.adv-item .no { font-size: 30px; font-weight: bold; color: #c9d8ef; line-height: 1; }
.adv-item .icon { font-size: 40px; margin: 14px 0; display: block; }
.adv-item h4 { font-size: 17px; color: var(--blue-dark); margin-bottom: 8px; }
.adv-item p { color: var(--text-sub); font-size: 13px; }

/* ============ 工程案例 ============ */
.case-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.case-item { position: relative; border-radius: var(--radius); overflow: hidden; height: 230px; cursor: pointer; }
.case-item img { width: 100%; height: 100%; object-fit: cover; transition: transform .4s; }
.case-item:hover img { transform: scale(1.06); }
.case-item .cap {
  position: absolute; left: 0; right: 0; bottom: 0; padding: 34px 16px 12px;
  background: linear-gradient(transparent, rgba(6, 24, 54, .82)); color: #fff; font-size: 14px;
}
.case-item .cap b { font-size: 15px; display: block; margin-bottom: 2px; }
.case-item .cap span { font-size: 12px; opacity: .85; }

/* ============ 新闻资讯 ============ */
.news-list { display: grid; grid-template-columns: 1fr 1fr; gap: 0 44px; }
.news-item {
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: 15px 6px; border-bottom: 1px dashed var(--line); transition: padding .2s;
}
.news-item:hover { padding-left: 12px; }
.news-item a.title { color: #333; font-size: 15px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.news-item a.title:hover { color: var(--blue); }
.news-item .date { color: var(--text-light); font-size: 13px; flex-shrink: 0; }

/* ============ 联系我们（首页/页尾） ============ */
.contact-box {
  background: var(--blue-grad); color: #fff; border-radius: 10px;
  padding: 46px 50px; display: flex; justify-content: space-between; align-items: center; gap: 30px; flex-wrap: wrap;
}
.contact-box .cb-title { font-size: 24px; font-weight: bold; margin-bottom: 6px; letter-spacing: 1px; }
.contact-box .cb-sub { opacity: .88; }
.contact-box .cb-tel { font-size: 30px; font-weight: bold; letter-spacing: 1px; }
.contact-box .cb-tel small { display: block; font-size: 13px; font-weight: normal; opacity: .8; margin-bottom: 4px; }
.contact-box .cb-tel .btn { display: inline-block; margin-top: 12px; background: #fff; color: var(--blue-dark); padding: 8px 26px; border-radius: 4px; font-size: 14px; font-weight: 600; }

/* ============ 页脚 ============ */
.footer { background: var(--footer-bg); color: #b8c0cc; font-size: 13px; padding: 44px 0 0; }
.footer .f-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1.2fr; gap: 36px; padding-bottom: 34px; }
.footer h5 { color: #fff; font-size: 15px; margin-bottom: 16px; position: relative; padding-bottom: 10px; }
.footer h5::after { content: ""; position: absolute; left: 0; bottom: 0; width: 30px; height: 2px; background: var(--blue-light); }
.footer .f-about p { color: #9aa4b2; line-height: 1.9; text-align: justify; }
.footer .f-nav li a { display: block; padding: 4px 0; color: #9aa4b2; transition: color .2s; }
.footer .f-nav li a:hover { color: var(--blue-light); }
.footer .f-contact li { padding: 5px 0; color: #9aa4b2; }
.footer .f-contact li b { color: #cfd6e0; font-weight: normal; }
.footer .f-logo img { height: 44px; margin-bottom: 12px; }
.footer .copyright { border-top: 1px solid #333a44; padding: 16px 0; text-align: center; color: #7c8694; font-size: 12px; }
.footer .copyright a { color: #7c8694; }
.footer .copyright a:hover { color: var(--blue-light); }

/* ============ 内页公共 ============ */
.page-banner { background: var(--blue-grad); color: #fff; padding: 46px 0; text-align: center; }
.page-banner h1 { font-size: 30px; letter-spacing: 2px; }
.page-banner p { opacity: .85; margin-top: 6px; font-size: 14px; }
.crumb { background: #f0f3f8; padding: 9px 0; font-size: 13px; color: var(--text-sub); }
.crumb a { color: var(--blue); }
.crumb a:hover { text-decoration: underline; }
.page-body { padding: 46px 0 60px; }

/* 分类页布局 */
.cat-layout { display: flex; gap: 26px; }
.cat-side { width: 250px; flex-shrink: 0; }
.cat-side .cat-menu { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.cat-side .cat-menu > h3 { background: var(--blue-grad); color: #fff; padding: 14px 18px; font-size: 16px; letter-spacing: 1px; }
.cat-side .cat-menu .group-title { background: #eef2f9; color: var(--blue-dark); font-weight: 600; padding: 10px 18px; font-size: 14px; border-top: 1px solid var(--line); }
.cat-side .cat-menu li a { display: block; padding: 10px 18px 10px 34px; color: #555; font-size: 13.5px; border-top: 1px solid #f2f4f8; transition: all .2s; cursor: pointer; }
.cat-side .cat-menu li a:hover, .cat-side .cat-menu li a.active { color: var(--blue); background: #f0f6ff; }
.cat-main { flex: 1; min-width: 0; }
.cat-main .filter-bar { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 22px; }
.cat-main .filter-bar button {
  padding: 7px 18px; border: 1px solid var(--line); background: #fff; color: #555;
  border-radius: 20px; font-size: 13px; cursor: pointer; transition: all .2s;
}
.cat-main .filter-bar button:hover, .cat-main .filter-bar button.active { background: var(--blue); border-color: var(--blue); color: #fff; }
.p-grid.full { grid-template-columns: repeat(3, 1fr); }
.p-grid .p-card .pic { height: 220px; }

/* 关于页 */
.about-page .intro-wrap { display: flex; gap: 36px; align-items: flex-start; }
.about-page .intro-wrap .txt { flex: 1.2; }
.about-page .intro-wrap .imgs { flex: 1; display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.about-page .intro-wrap .imgs img { height: 150px; width: 100%; object-fit: cover; border-radius: var(--radius); }
.about-page h3.blk-title { font-size: 20px; color: var(--blue-dark); margin: 40px 0 18px; padding-left: 12px; border-left: 4px solid var(--blue-light); }
.about-page p { color: var(--text-sub); margin-bottom: 12px; text-align: justify; }
.feature-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.feature-item { display: flex; gap: 14px; background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 20px; }
.feature-item .fi-no { font-size: 26px; font-weight: bold; color: var(--blue-light); flex-shrink: 0; }
.feature-item h4 { color: var(--blue-dark); font-size: 15px; margin-bottom: 4px; }
.feature-item p { color: var(--text-sub); font-size: 13px; margin: 0; }
.timeline { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.timeline .tl-item { text-align: center; background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 22px 12px; }
.timeline .tl-item .y { font-size: 22px; font-weight: bold; color: var(--blue); }
.timeline .tl-item p { font-size: 13px; color: var(--text-sub); margin: 8px 0 0; }

/* 案例页 */
.case-page-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.case-card { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; transition: all .25s; }
.case-card:hover { transform: translateY(-4px); box-shadow: 0 10px 24px rgba(10, 61, 143, .10); }
.case-card .pic { height: 200px; overflow: hidden; }
.case-card .pic img { width: 100%; height: 100%; object-fit: cover; transition: transform .4s; }
.case-card:hover .pic img { transform: scale(1.05); }
.case-card .info { padding: 16px 18px 20px; }
.case-card .info h4 { font-size: 15px; color: #222; margin-bottom: 6px; }
.case-card .info p { font-size: 13px; color: var(--text-sub); display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }

/* 新闻列表页 */
.news-page-list .news-row {
  display: flex; align-items: center; gap: 18px; background: #fff;
  border: 1px solid var(--line); border-radius: var(--radius); padding: 16px 20px; margin-bottom: 14px;
  transition: all .2s;
}
.news-page-list .news-row:hover { border-color: var(--blue-light); box-shadow: 0 6px 16px rgba(10, 61, 143, .08); }
.news-page-list .news-row .nd { background: var(--blue-grad); color: #fff; text-align: center; border-radius: var(--radius); padding: 8px 12px; flex-shrink: 0; min-width: 64px; }
.news-page-list .news-row .nd b { display: block; font-size: 20px; line-height: 1.2; }
.news-page-list .news-row .nd span { font-size: 11px; opacity: .9; }
.news-page-list .news-row .nbody { flex: 1; }
.news-page-list .news-row .nbody h4 { font-size: 15px; margin-bottom: 4px; }
.news-page-list .news-row .nbody h4 a:hover { color: var(--blue); }
.news-page-list .news-row .nbody p { font-size: 13px; color: var(--text-sub); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.news-page-list .news-row .arrow { color: var(--text-light); flex-shrink: 0; }

/* 新闻详情 */
.detail-box { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 34px 40px; }
.detail-box h1 { font-size: 24px; color: var(--blue-dark); text-align: center; }
.detail-box .meta { text-align: center; color: var(--text-light); font-size: 13px; padding: 12px 0 22px; border-bottom: 1px solid var(--line); margin-bottom: 24px; }
.detail-box .content p { margin-bottom: 14px; text-align: justify; color: var(--text-sub); }
.detail-box .content h3 { color: var(--blue-dark); font-size: 17px; margin: 20px 0 10px; }
.detail-box .content ul { padding-left: 20px; margin-bottom: 14px; }
.detail-box .content ul li { list-style: disc; color: var(--text-sub); margin-bottom: 6px; }
.detail-nav { display: flex; justify-content: space-between; margin-top: 28px; padding-top: 18px; border-top: 1px solid var(--line); font-size: 13px; }
.detail-nav a { color: var(--blue); }
.detail-nav a:hover { text-decoration: underline; }

/* 联系页 */
.contact-grid { display: grid; grid-template-columns: 1.1fr 1fr; gap: 28px; }
.contact-card { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 28px 30px; }
.contact-card h3 { font-size: 18px; color: var(--blue-dark); margin-bottom: 18px; padding-bottom: 12px; border-bottom: 2px solid #eef2f9; }
.contact-card ul li { display: flex; gap: 12px; padding: 9px 0; color: var(--text-sub); }
.contact-card ul li .ci { width: 36px; height: 36px; border-radius: 50%; background: #eef4fc; color: var(--blue); display: flex; align-items: center; justify-content: center; flex-shrink: 0; font-size: 16px; }
.contact-card ul li .ci b { font-size: 15px; }
.contact-card ul li .c-txt b { color: #222; display: block; }
.map-box { background: linear-gradient(135deg, #e8eef7, #d5e3f5); border: 1px dashed #b9cdea; border-radius: var(--radius); height: 260px; display: flex; flex-direction: column; align-items: center; justify-content: center; color: #7d95bd; }
.map-box .big { font-size: 34px; margin-bottom: 10px; }
.contact-form { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 28px 30px; }
.contact-form h3 { font-size: 18px; color: var(--blue-dark); margin-bottom: 18px; padding-bottom: 12px; border-bottom: 2px solid #eef2f9; }
.contact-form .f-row { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-bottom: 14px; }
.contact-form input, .contact-form textarea {
  width: 100%; padding: 10px 12px; border: 1px solid var(--line); border-radius: 4px;
  font-size: 14px; font-family: inherit; outline: none; transition: border .2s;
}
.contact-form input:focus, .contact-form textarea:focus { border-color: var(--blue-light); }
.contact-form textarea { height: 110px; resize: vertical; }
.contact-form .btn-submit { background: var(--blue-grad); color: #fff; border: none; padding: 11px 40px; border-radius: 4px; font-size: 15px; cursor: pointer; transition: opacity .2s; }
.contact-form .btn-submit:hover { opacity: .88; }
.form-tip { margin-top: 10px; font-size: 13px; color: var(--blue); display: none; }

/* 联系页（contact.html 补充类） */
.contact-info { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 28px 30px; }
.contact-info h3 { font-size: 18px; color: var(--blue-dark); margin-bottom: 18px; padding-bottom: 12px; border-bottom: 2px solid #eef2f9; }
.c-list li { padding: 8px 0; color: var(--text-sub); font-size: 14px; }
.c-list li b { color: #222; }
.c-tip { margin-top: 16px; padding: 10px 14px; background: #fff8e6; border: 1px solid #f3e2b0; border-radius: 4px; color: #9a7b24; font-size: 13px; }
.contact-form select {
  width: 100%; padding: 10px 12px; border: 1px solid var(--line); border-radius: 4px;
  font-size: 14px; font-family: inherit; outline: none; background: #fff; color: var(--text-main);
}
.contact-form select:focus { border-color: var(--blue-light); }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-bottom: 14px; }
.form-msg { margin-top: 12px; font-size: 14px; color: var(--blue); }
.map-tip { color: var(--text-sub); font-size: 14px; margin-bottom: 14px; }
.map-placeholder {
  background: linear-gradient(135deg, #e8eef7, #d5e3f5); border: 1px dashed #b9cdea; border-radius: var(--radius);
  height: 260px; display: flex; flex-direction: column; align-items: center; justify-content: center;
  color: #7d95bd; text-align: center;
}
.map-placeholder b { font-size: 18px; color: #5d7bab; }
.map-placeholder p { font-size: 13px; margin-top: 6px; }

/* 返回顶部 */
#toTop {
  position: fixed; right: 24px; bottom: 30px; width: 44px; height: 44px; border-radius: 50%;
  background: var(--blue-grad); color: #fff; border: none; font-size: 20px; cursor: pointer;
  box-shadow: 0 6px 16px rgba(10, 61, 143, .3); z-index: 998; display: none;
}
#toTop.show { display: block; }

/* ============ 响应式 ============ */
@media (max-width: 1024px) {
  .p-grid { grid-template-columns: repeat(3, 1fr); }
  .case-grid, .case-page-grid { grid-template-columns: repeat(2, 1fr); }
  .adv-grid { grid-template-columns: repeat(2, 1fr); }
  .footer .f-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
  .topbar .hot-words { display: none; }
  .nav-toggle { display: block; }
  .nav { position: absolute; top: 78px; left: 0; right: 0; background: #fff; border-top: 1px solid var(--line); display: none; box-shadow: 0 8px 16px rgba(0,0,0,.08); }
  .nav.open { display: block; }
  .nav ul { flex-direction: column; }
  .nav ul li a { line-height: 46px; padding: 0 20px; }
  .nav ul li a.active::after { display: none; }
  .banner { height: 380px; }
  .banner .slide .content h2 { font-size: 28px; }
  .banner .slide .content p { font-size: 14px; }
  .product-wrap { flex-direction: column; }
  .p-cats { width: 100%; }
  .p-grid { grid-template-columns: repeat(2, 1fr); }
  .about-wrap { flex-direction: column; }
  .news-list { grid-template-columns: 1fr; }
  .contact-box { padding: 30px 24px; }
  .cat-layout { flex-direction: column; }
  .cat-side { width: 100%; }
  .timeline { grid-template-columns: repeat(2, 1fr); }
  .contact-grid { grid-template-columns: 1fr; }
  .about-page .intro-wrap { flex-direction: column; }
  .feature-grid { grid-template-columns: 1fr; }
  .detail-box { padding: 22px 18px; }
  .contact-form .f-row { grid-template-columns: 1fr; }
}