/* ============================================================
   厦门立特煜天科技有限公司 官网样式
   商务工业蓝风格 · 响应式
   ============================================================ */
:root {
  --primary: #1a5cb0;        /* 立特蓝 */
  --primary-dark: #10406f;
  --primary-darker: #0b2d52;
  --accent: #d43a2f;         /* 立特红点缀 */
  --text: #2b3440;
  --text-light: #6b7684;
  --bg-light: #f4f6f9;
  --bg-white: #ffffff;
  --border: #e3e8ef;
  --radius: 6px;
  --shadow: 0 2px 16px rgba(16, 64, 111, 0.08);
  --shadow-hover: 0 8px 28px rgba(16, 64, 111, 0.16);
  --container: 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);
  background: var(--bg-white);
  line-height: 1.7;
  font-size: 15px;
}

img { max-width: 100%; display: block; }
a { text-decoration: none; color: inherit; transition: color 0.25s; }
ul { list-style: none; }

.container { max-width: var(--container); margin: 0 auto; padding: 0 20px; }

/* ---------- 顶部信息条 ---------- */
.topbar {
  background: var(--primary-darker);
  color: rgba(255, 255, 255, 0.85);
  font-size: 13px;
}
.topbar .container {
  display: flex; justify-content: space-between; align-items: center;
  height: 34px;
}
.topbar span + span { margin-left: 22px; }
.topbar a { color: rgba(255, 255, 255, 0.85); }
.topbar a:hover { color: #fff; }

/* ---------- 主导航 ---------- */
.header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255, 255, 255, 0.97);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 1px 10px rgba(0, 0, 0, 0.04);
}
.header .container {
  display: flex; align-items: center; justify-content: space-between;
  height: 74px;
}
.logo img { height: 46px; width: auto; }
.nav { display: flex; align-items: center; gap: 6px; }
.nav a {
  display: block; padding: 8px 18px;
  font-size: 16px; font-weight: 500; color: var(--text);
  border-radius: 4px; position: relative;
}
.nav a:hover { color: var(--primary); }
.nav a.active { color: var(--primary); font-weight: 600; }
.nav a.active::after {
  content: ""; position: absolute; left: 18px; right: 18px; bottom: 2px;
  height: 3px; background: var(--accent); border-radius: 2px;
}
.nav .nav-cta {
  background: var(--primary); color: #fff; margin-left: 12px; padding: 9px 22px;
}
.nav .nav-cta:hover { background: var(--primary-dark); color: #fff; }
.nav .nav-cta.active { color: #fff; }
.nav .nav-cta.active::after { display: none; }

/* 移动端汉堡按钮 */
.menu-toggle {
  display: none; flex-direction: column; gap: 5px;
  background: none; border: none; cursor: pointer; padding: 8px;
}
.menu-toggle span {
  width: 26px; height: 3px; background: var(--primary-dark);
  border-radius: 2px; transition: all 0.3s;
}

/* ---------- Banner 轮播 ---------- */
.banner { position: relative; height: 560px; overflow: hidden; }
.banner .slide {
  position: absolute; inset: 0; opacity: 0; transition: opacity 0.9s ease;
  display: flex; align-items: center;
}
.banner .slide.on { opacity: 1; z-index: 1; }
.banner .slide .bg {
  position: absolute; inset: 0;
  background-size: cover; background-position: center;
}
.banner .slide.s1 .bg { background-image: linear-gradient(100deg, rgba(11,45,82,0.92) 0%, rgba(16,64,111,0.55) 45%, rgba(16,64,111,0.18) 100%), url("../img/hero-system.jpg"); }
.banner .slide.s2 .bg { background-image: linear-gradient(100deg, rgba(11,45,82,0.92) 0%, rgba(16,64,111,0.55) 45%, rgba(16,64,111,0.18) 100%), url("../img/hero-factory.jpg"); }
.banner .slide.s3 .bg { background-image: linear-gradient(100deg, rgba(11,45,82,0.92) 0%, rgba(16,64,111,0.55) 45%, rgba(16,64,111,0.18) 100%), url("../img/hero-port.jpg"); background-position: center 30%; }
.banner .slide .inner {
  position: relative; z-index: 2; color: #fff; max-width: 640px;
  padding: 0 20px; margin-left: calc((100% - var(--container)) / 2);
}
.banner .slide .kicker {
  display: inline-block; font-size: 14px; letter-spacing: 4px;
  border: 1px solid rgba(255,255,255,0.5); padding: 4px 14px;
  border-radius: 3px; margin-bottom: 22px;
}
.banner .slide h2 {
  font-size: 42px; line-height: 1.3; margin-bottom: 18px; font-weight: 700;
}
.banner .slide p {
  font-size: 17px; color: rgba(255,255,255,0.88); margin-bottom: 34px;
  max-width: 520px;
}
.banner .slide .btn {
  display: inline-block; background: var(--accent); color: #fff;
  padding: 13px 38px; border-radius: 4px; font-size: 16px; letter-spacing: 2px;
}
.banner .slide .btn:hover { background: #b52e24; }
.banner .dots {
  position: absolute; bottom: 26px; left: 50%; transform: translateX(-50%);
  display: flex; gap: 10px; z-index: 5;
}
.banner .dots button {
  width: 34px; height: 4px; border: none; border-radius: 2px;
  background: rgba(255,255,255,0.4); cursor: pointer; transition: background 0.3s;
}
.banner .dots button.on { background: #fff; }

/* ---------- 通用区块 ---------- */
.section { padding: 80px 0; }
.section.gray { background: var(--bg-light); }
.sec-head { text-align: center; margin-bottom: 52px; }
.sec-head .en {
  font-size: 14px; letter-spacing: 3px; color: var(--accent);
  text-transform: uppercase; font-weight: 600;
}
.sec-head h2 {
  font-size: 32px; color: var(--primary-dark); margin-top: 6px;
  font-weight: 700;
}
.sec-head .line {
  width: 56px; height: 4px; background: var(--primary);
  margin: 18px auto 0; border-radius: 2px; position: relative;
}
.sec-head .line::after {
  content: ""; position: absolute; left: 62px; top: 1px;
  width: 10px; height: 2px; background: var(--accent); border-radius: 1px;
}
.sec-head p.desc { color: var(--text-light); margin-top: 16px; max-width: 720px; margin-left: auto; margin-right: auto; }

/* ---------- 首页产品分类 ---------- */
.cat-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 26px;
}
.cat-card {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  overflow: hidden; transition: transform 0.3s, box-shadow 0.3s;
  display: block;
}
.cat-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-hover); }
.cat-card .pic { height: 220px; overflow: hidden; }
.cat-card .pic img {
  width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s;
}
.cat-card:hover .pic img { transform: scale(1.06); }
.cat-card .txt { padding: 22px 24px 26px; }
.cat-card .txt h3 { font-size: 19px; color: var(--primary-dark); margin-bottom: 8px; }
.cat-card .txt h3 i {
  font-style: normal; color: var(--accent); font-size: 14px;
  margin-right: 8px; font-family: Georgia, serif;
}
.cat-card .txt p { color: var(--text-light); font-size: 14px; }

/* ---------- 精选产品 ---------- */
.prod-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px;
}
.prod-card {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  overflow: hidden; transition: transform 0.3s, box-shadow 0.3s;
  display: flex; flex-direction: column;
}
.prod-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-hover); }
.prod-card .pic {
  height: 190px; display: flex; align-items: center; justify-content: center;
  background: #fff; overflow: hidden; padding: 12px;
}
.prod-card .pic img { max-height: 100%; object-fit: contain; transition: transform 0.4s; }
.prod-card:hover .pic img { transform: scale(1.05); }
.prod-card .txt { padding: 16px 18px 20px; border-top: 1px solid var(--border); }
.prod-card .txt .tag {
  display: inline-block; font-size: 12px; color: var(--primary);
  background: #eaf1fa; padding: 2px 10px; border-radius: 20px; margin-bottom: 8px;
}
.prod-card .txt h3 { font-size: 16px; color: var(--text); line-height: 1.5; }
.prod-more { text-align: center; margin-top: 44px; }
.btn-outline {
  display: inline-block; border: 2px solid var(--primary); color: var(--primary);
  padding: 11px 42px; border-radius: 4px; font-size: 16px; letter-spacing: 1px;
  transition: all 0.3s;
}
.btn-outline:hover { background: var(--primary); color: #fff; }

/* ---------- 关于我们 ---------- */
.about-wrap { display: grid; grid-template-columns: 1.05fr 1fr; gap: 56px; align-items: center; }
.about-wrap .pic { position: relative; }
.about-wrap .pic img { border-radius: var(--radius); width: 100%; height: 420px; object-fit: cover; }
.about-wrap .pic::before {
  content: ""; position: absolute; left: -18px; bottom: -18px;
  width: 60%; height: 60%; border: 3px solid var(--primary); border-radius: var(--radius);
  z-index: -1; opacity: 0.35;
}
.about-wrap .en-title {
  color: var(--accent); font-size: 14px; letter-spacing: 3px;
  text-transform: uppercase; font-weight: 600;
}
.about-wrap h2 { font-size: 30px; color: var(--primary-dark); margin: 8px 0 22px; }
.about-wrap p { color: var(--text-light); margin-bottom: 14px; text-align: justify; }
.about-nums { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; margin-top: 34px; }
.about-nums .num { text-align: center; background: var(--bg-light); border-radius: var(--radius); padding: 20px 8px; }
.about-nums .num b { display: block; font-size: 30px; color: var(--primary); }
.about-nums .num b i { font-style: normal; font-size: 16px; }
.about-nums .num span { font-size: 13px; color: var(--text-light); }

/* ---------- 应用行业 ---------- */
.ind-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.ind-card {
  position: relative; height: 230px; border-radius: var(--radius); overflow: hidden;
}
.ind-card img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s; }
.ind-card:hover img { transform: scale(1.08); }
.ind-card .mask {
  position: absolute; inset: 0;
  background: linear-gradient(to top, rgba(11,45,82,0.88) 0%, rgba(11,45,82,0.15) 55%, transparent 100%);
  display: flex; align-items: flex-end; padding: 20px;
}
.ind-card .mask h3 { color: #fff; font-size: 19px; font-weight: 600; }
.ind-card .mask span { color: rgba(255,255,255,0.8); font-size: 13px; display: block; }

/* ---------- 优势 ---------- */
.adv-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.adv-card {
  background: #fff; border-radius: var(--radius); padding: 34px 26px;
  border: 1px solid var(--border); transition: transform 0.3s, box-shadow 0.3s;
}
.adv-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-hover); }
.adv-card .ico {
  width: 58px; height: 58px; border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 20px; color: #fff; font-size: 26px;
}
.adv-card h3 { font-size: 18px; color: var(--primary-dark); margin-bottom: 10px; }
.adv-card p { color: var(--text-light); font-size: 14px; }

/* ---------- 联系 CTA ---------- */
.cta-band {
  background: linear-gradient(115deg, var(--primary-darker), var(--primary) 60%, #2e77d0);
  color: #fff; padding: 66px 0;
}
.cta-band .container { display: flex; align-items: center; justify-content: space-between; gap: 30px; flex-wrap: wrap; }
.cta-band h2 { font-size: 30px; margin-bottom: 8px; }
.cta-band p { color: rgba(255,255,255,0.85); }
.cta-band .btn-white {
  background: #fff; color: var(--primary-dark); padding: 14px 44px;
  border-radius: 4px; font-size: 16px; font-weight: 600; white-space: nowrap;
}
.cta-band .btn-white:hover { background: var(--accent); color: #fff; }

/* ---------- 页脚 ---------- */
.footer { background: var(--primary-darker); color: rgba(255,255,255,0.75); padding: 64px 0 0; }
.footer-grid {
  display: grid; grid-template-columns: 1.4fr 1fr 1fr 1.2fr; gap: 40px;
  padding-bottom: 46px;
}
.footer h4 { color: #fff; font-size: 17px; margin-bottom: 20px; position: relative; padding-bottom: 12px; }
.footer h4::after { content: ""; position: absolute; left: 0; bottom: 0; width: 28px; height: 3px; background: var(--accent); border-radius: 2px; }
.footer .flogo img { height: 44px; background: #fff; border-radius: 4px; padding: 6px 10px; margin-bottom: 18px; }
.footer p, .footer li { font-size: 14px; margin-bottom: 10px; }
.footer a:hover { color: #fff; }
.footer li a { display: block; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.12); padding: 18px 0;
  text-align: center; font-size: 13px; color: rgba(255,255,255,0.5);
}

/* ---------- 页头 banner（内页） ---------- */
.page-banner {
  background:
    linear-gradient(100deg, rgba(11,45,82,0.9), rgba(26,92,176,0.75)),
    url("../img/hero-system.jpg") center/cover;
  color: #fff; padding: 88px 0; text-align: center;
}
.page-banner h1 { font-size: 36px; letter-spacing: 4px; }
.page-banner .crumb { margin-top: 12px; font-size: 14px; color: rgba(255,255,255,0.75); }
.page-banner .crumb a:hover { color: #fff; }

/* ---------- 产品中心页 ---------- */
.prod-layout { display: grid; grid-template-columns: 250px 1fr; gap: 30px; align-items: start; }
.prod-side { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; position: sticky; top: 94px; }
.prod-side .side-title { background: var(--primary); color: #fff; padding: 14px 20px; font-size: 17px; font-weight: 600; }
.prod-side a {
  display: block; padding: 13px 20px; font-size: 15px;
  border-bottom: 1px solid var(--border); color: var(--text);
  border-left: 3px solid transparent;
}
.prod-side a:hover { background: var(--bg-light); color: var(--primary); }
.prod-side a.on { border-left-color: var(--accent); background: #eaf1fa; color: var(--primary); font-weight: 600; }

.prod-grid.page { grid-template-columns: repeat(3, 1fr); }

/* 产品详情（页内手风琴） */
.prod-detail { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); margin-bottom: 26px; overflow: hidden; }
.prod-detail .head {
  display: flex; justify-content: space-between; align-items: center;
  padding: 18px 24px; cursor: pointer; background: var(--bg-light);
  transition: background 0.2s;
}
.prod-detail .head:hover { background: #eaf1fa; }
.prod-detail .head h3 { font-size: 17px; color: var(--primary-dark); }
.prod-detail .head .arrow { color: var(--primary); font-size: 14px; transition: transform 0.3s; }
.prod-detail.open .head .arrow { transform: rotate(180deg); }
.prod-detail .body { display: none; padding: 26px 24px; }
.prod-detail.open .body { display: grid; grid-template-columns: 380px 1fr; gap: 30px; }
.prod-detail .body .pic img { width: 100%; border: 1px solid var(--border); border-radius: 4px; }
.prod-detail .body h4 { color: var(--primary); font-size: 15px; margin: 14px 0 6px; }
.prod-detail .body h4:first-child { margin-top: 0; }
.prod-detail .body p, .prod-detail .body li { color: var(--text-light); font-size: 14px; }
.prod-detail .body ul li { padding-left: 16px; position: relative; margin-bottom: 6px; }
.prod-detail .body ul li::before {
  content: ""; position: absolute; left: 0; top: 9px;
  width: 6px; height: 6px; background: var(--accent); border-radius: 50%;
}
.prod-detail table { width: 100%; border-collapse: collapse; margin-top: 10px; font-size: 13px; }
.prod-detail table th { background: var(--primary); color: #fff; padding: 8px 10px; font-weight: 500; }
.prod-detail table td { border: 1px solid var(--border); padding: 7px 10px; text-align: center; color: var(--text); }
.prod-detail table tr:nth-child(even) td { background: var(--bg-light); }

/* ---------- 关于我们页 ---------- */
.about-body p { color: var(--text-light); text-align: justify; margin-bottom: 16px; font-size: 15.5px; }
.about-2col { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: center; margin-top: 46px; }
.about-2col img { border-radius: var(--radius); height: 330px; width: 100%; object-fit: cover; }
.culture-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; margin-top: 40px; }
.culture-card { background: var(--bg-light); border-radius: var(--radius); padding: 30px 26px; border-top: 3px solid var(--primary); }
.culture-card h3 { color: var(--primary-dark); font-size: 18px; margin-bottom: 10px; }
.culture-card p { color: var(--text-light); font-size: 14px; }

/* ---------- 联系我们页 ---------- */
.contact-wrap { display: grid; grid-template-columns: 1fr 1.2fr; gap: 44px; align-items: start; }
.contact-info .item { display: flex; gap: 16px; margin-bottom: 28px; }
.contact-info .item .ico {
  flex: none; width: 50px; height: 50px; border-radius: 8px;
  background: #eaf1fa; color: var(--primary); font-size: 22px;
  display: flex; align-items: center; justify-content: center;
}
.contact-info .item h3 { font-size: 16px; color: var(--primary-dark); margin-bottom: 4px; }
.contact-info .item p { color: var(--text-light); font-size: 14.5px; }
.contact-form { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 34px; }
.contact-form h3 { font-size: 20px; color: var(--primary-dark); margin-bottom: 22px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.contact-form label { display: block; font-size: 14px; margin-bottom: 16px; color: var(--text); }
.contact-form label span { color: var(--accent); }
.contact-form input, .contact-form textarea {
  width: 100%; margin-top: 6px; padding: 11px 13px;
  border: 1px solid #ccd4de; border-radius: 4px; font-size: 14px;
  font-family: inherit; outline: none; transition: border 0.2s;
}
.contact-form input:focus, .contact-form textarea:focus { border-color: var(--primary); }
.contact-form textarea { resize: vertical; min-height: 120px; }
.contact-form button {
  background: var(--primary); color: #fff; border: none; cursor: pointer;
  padding: 13px 46px; font-size: 16px; border-radius: 4px; letter-spacing: 2px;
}
.contact-form button:hover { background: var(--primary-dark); }
.form-tip { display: none; margin-top: 14px; padding: 10px 14px; border-radius: 4px; font-size: 14px; }
.form-tip.ok { display: block; background: #e6f6ec; color: #1d7a3e; border: 1px solid #bfe6cd; }
.form-tip.err { display: block; background: #fdeeee; color: #b52e24; border: 1px solid #f2c7c3; }

/* ---------- 回到顶部 ---------- */
.back-top {
  position: fixed; right: 26px; bottom: 30px; width: 46px; height: 46px;
  background: var(--primary); color: #fff; border: none; border-radius: 6px;
  font-size: 20px; cursor: pointer; opacity: 0; pointer-events: none;
  transition: opacity 0.3s; z-index: 99; box-shadow: var(--shadow);
}
.back-top.show { opacity: 1; pointer-events: auto; }
.back-top:hover { background: var(--accent); }

/* ---------- 入场动画 ---------- */
.reveal { opacity: 0; transform: translateY(28px); transition: opacity 0.7s ease, transform 0.7s ease; }
.reveal.vis { opacity: 1; transform: none; }

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 1080px) {
  .prod-grid { grid-template-columns: repeat(3, 1fr); }
  .prod-grid.page { grid-template-columns: repeat(2, 1fr); }
  .adv-grid, .ind-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .banner .slide h2 { font-size: 34px; }
  .prod-detail.open .body { grid-template-columns: 1fr; }
}

@media (max-width: 820px) {
  .topbar .container span.hide-m { display: none; }
  .menu-toggle { display: flex; }
  .nav {
    position: fixed; top: 74px; left: 0; right: 0;
    background: #fff; flex-direction: column; align-items: stretch;
    padding: 12px 20px 20px; gap: 2px;
    border-bottom: 1px solid var(--border);
    box-shadow: 0 12px 24px rgba(0,0,0,0.08);
    transform: translateY(-130%); transition: transform 0.35s ease;
    z-index: 90; max-height: calc(100vh - 74px); overflow: auto;
  }
  .nav.open { transform: none; }
  .nav a { padding: 13px 10px; border-bottom: 1px solid var(--border); }
  .nav a.active::after { display: none; }
  .nav .nav-cta { margin: 14px 0 0; text-align: center; }

  .banner { height: 440px; }
  .banner .slide h2 { font-size: 28px; }
  .banner .slide p { font-size: 15px; }
  .banner .slide .inner { margin: 0 auto; text-align: center; }

  .section { padding: 56px 0; }
  .sec-head h2 { font-size: 26px; }
  .cat-grid, .prod-grid { grid-template-columns: repeat(2, 1fr); gap: 16px; }
  .about-wrap, .contact-wrap, .about-2col { grid-template-columns: 1fr; gap: 34px; }
  .about-wrap .pic img { height: 300px; }
  .prod-layout { grid-template-columns: 1fr; }
  .prod-side { position: static; }
  .prod-side a { padding: 12px 16px; }
  .culture-grid { grid-template-columns: 1fr; }
  .cta-band .container { justify-content: center; text-align: center; }
  .footer-grid { grid-template-columns: 1fr; gap: 30px; }
}

@media (max-width: 520px) {
  .prod-grid, .prod-grid.page { grid-template-columns: 1fr; }
  .cat-grid { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .banner { height: 400px; }
  .banner .slide h2 { font-size: 24px; }
  .page-banner h1 { font-size: 27px; }
  .about-nums { grid-template-columns: repeat(3, 1fr); gap: 10px; }
  .about-nums .num b { font-size: 22px; }
  .contact-form { padding: 22px 18px; }
}