/* =========================================================
   龙鼎鸿图（北京）科技有限公司 — 官网样式
   简约 · 时尚 · 科技感
   ========================================================= */

:root {
  --primary: #2E6BFF;
  --primary-2: #12C9F0;
  --accent: #FF8A2E;
  --ink: #0F1B3D;
  --text: #3D4A63;
  --muted: #6B7A99;
  --bg: #FFFFFF;
  --bg-soft: #F5F8FF;
  --line: #E6ECF8;
  --navy: #0B1430;
  --radius: 16px;
  --radius-sm: 10px;
  --shadow-sm: 0 4px 16px rgba(15, 27, 61, 0.06);
  --shadow-md: 0 12px 32px rgba(15, 27, 61, 0.10);
  --shadow-lg: 0 24px 56px rgba(46, 107, 255, 0.16);
  --grad: linear-gradient(120deg, #2E6BFF, #12C9F0);
  --grad-gold: linear-gradient(120deg, #FFC24B, #FF8A2E);
  --font: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", -apple-system, "Segoe UI", Roboto, sans-serif;
  --container: 1200px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- 通用按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 26px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease, color 0.2s ease;
}
.btn--primary {
  background: var(--grad);
  color: #fff;
  box-shadow: 0 8px 24px rgba(46, 107, 255, 0.30);
}
.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 12px 30px rgba(46, 107, 255, 0.40); }
.btn--ghost {
  background: transparent;
  color: var(--ink);
  border-color: #D6DFF2;
}
.btn--ghost:hover { border-color: var(--primary); color: var(--primary); transform: translateY(-2px); }
.btn--light {
  background: #fff;
  color: var(--primary);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.18);
}
.btn--light:hover { transform: translateY(-2px); box-shadow: 0 12px 30px rgba(0, 0, 0, 0.26); }

/* ---------- 顶部导航 ---------- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.82);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: box-shadow 0.3s ease, border-color 0.3s ease;
}
.nav.is-scrolled {
  border-color: var(--line);
  box-shadow: 0 4px 20px rgba(15, 27, 61, 0.06);
}
.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
  gap: 20px;
}
.nav__logo { height: 46px; width: auto; }
.nav__links { display: flex; align-items: center; gap: 34px; }
.nav__links a {
  font-size: 15px;
  font-weight: 500;
  color: var(--text);
  position: relative;
  padding: 6px 0;
  transition: color 0.2s ease;
}
.nav__links a::after {
  content: "";
  position: absolute;
  left: 0; bottom: 0;
  width: 0; height: 2px;
  border-radius: 2px;
  background: var(--grad);
  transition: width 0.25s ease;
}
.nav__links a:hover { color: var(--primary); }
.nav__links a:hover::after { width: 100%; }
.nav__cta { padding: 10px 22px; font-size: 14px; }

.nav__burger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: 0;
  cursor: pointer;
  padding: 8px;
}
.nav__burger span {
  width: 22px; height: 2px;
  background: var(--ink);
  border-radius: 2px;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

/* ---------- Hero ---------- */
.hero {
  position: relative;
  padding: 180px 0 90px;
  background:
    radial-gradient(1000px 500px at 85% -10%, rgba(18, 201, 240, 0.16), transparent 60%),
    radial-gradient(800px 420px at -10% 20%, rgba(46, 107, 255, 0.14), transparent 60%),
    linear-gradient(180deg, #F7FAFF 0%, #FFFFFF 100%);
  overflow: hidden;
}
.hero__bg { position: absolute; inset: 0; pointer-events: none; }
.hero__circuit { position: absolute; inset: 0; width: 100%; height: 100%; }
.hero__orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(70px);
  opacity: 0.5;
}
.hero__orb--1 { width: 380px; height: 380px; top: -120px; right: -80px; background: rgba(46, 107, 255, 0.28); }
.hero__orb--2 { width: 300px; height: 300px; bottom: -120px; left: -80px; background: rgba(18, 201, 240, 0.24); }

.hero__inner { position: relative; text-align: center; }
.hero__tag {
  display: inline-block;
  padding: 8px 18px;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 600;
  color: var(--primary);
  background: rgba(46, 107, 255, 0.08);
  border: 1px solid rgba(46, 107, 255, 0.18);
  margin-bottom: 26px;
}
.hero__title {
  font-size: clamp(40px, 6vw, 68px);
  font-weight: 800;
  line-height: 1.18;
  color: var(--ink);
  letter-spacing: 1px;
}
.grad-text {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero__desc {
  max-width: 640px;
  margin: 24px auto 0;
  font-size: 17px;
  color: var(--muted);
}
.hero__actions {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-top: 36px;
  flex-wrap: wrap;
}
.hero__stats {
  display: flex;
  justify-content: center;
  gap: 0;
  margin-top: 64px;
  background: rgba(255, 255, 255, 0.75);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  backdrop-filter: blur(6px);
  overflow: hidden;
}
.hero__stat {
  flex: 1;
  padding: 24px 12px;
  text-align: center;
}
.hero__stat + .hero__stat { border-left: 1px solid var(--line); }
.hero__stat b {
  display: block;
  font-size: 28px;
  font-weight: 800;
  color: var(--ink);
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero__stat span { font-size: 13px; color: var(--muted); }

/* ---------- 通用区块 ---------- */
.section { padding: 104px 0; }
.section--soft { background: var(--bg-soft); }
.section__head { text-align: center; max-width: 640px; margin: 0 auto 56px; }
.section__eyebrow {
  display: inline-block;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 3px;
  color: var(--primary);
  text-transform: uppercase;
  margin-bottom: 10px;
}
.section__title {
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 800;
  color: var(--ink);
  letter-spacing: 0.5px;
}
.section__sub { margin-top: 14px; color: var(--muted); font-size: 16px; }

/* ---------- 关于我们 ---------- */
.about__grid {
  display: grid;
  grid-template-columns: 1fr 1.1fr;
  gap: 64px;
  align-items: start;
}
.about__text p { margin-bottom: 18px; color: var(--text); }
.about__text strong { color: var(--primary); font-weight: 700; }
.about__features { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.about__feature {
  display: flex;
  gap: 14px;
  padding: 22px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.about__feature:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }
.about__feature .icon {
  flex-shrink: 0;
  width: 34px; height: 34px;
  fill: none;
  stroke: url(#gradSvg);
  stroke: var(--primary);
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
  padding: 6px;
  border-radius: 9px;
  background: rgba(46, 107, 255, 0.08);
  box-sizing: border-box;
}
.about__feature b { color: var(--ink); font-size: 16px; }
.about__feature p { margin-top: 4px; font-size: 13.5px; color: var(--muted); }

/* ---------- 产品筛选 ---------- */
.filter {
  display: flex;
  justify-content: center;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 44px;
}
.filter__btn {
  padding: 10px 20px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: #fff;
  font-size: 14.5px;
  font-weight: 600;
  color: var(--text);
  cursor: pointer;
  transition: all 0.2s ease;
}
.filter__btn i {
  font-style: normal;
  font-size: 12px;
  margin-left: 6px;
  color: var(--muted);
  background: var(--bg-soft);
  border-radius: 999px;
  padding: 2px 8px;
}
.filter__btn:hover { border-color: var(--primary); color: var(--primary); }
.filter__btn.is-active {
  background: var(--grad);
  color: #fff;
  border-color: transparent;
  box-shadow: 0 6px 18px rgba(46, 107, 255, 0.28);
}
.filter__btn.is-active i { background: rgba(255, 255, 255, 0.22); color: #fff; }

/* ---------- 产品网格 ---------- */
.products {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 22px;
}
.product {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: transform 0.25s ease, box-shadow 0.25s ease, opacity 0.3s ease;
}
.product:hover { transform: translateY(-6px); box-shadow: var(--shadow-md); }
.product.is-hidden { display: none; }

.product__media {
  background: linear-gradient(160deg, #F3F6FC, #EDF2FB);
  aspect-ratio: 1 / 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 18px;
  position: relative;
  overflow: hidden;
}
.product__media::after {
  content: attr(data-tag);
  position: absolute;
  top: 12px; left: 12px;
  padding: 4px 10px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 600;
  color: var(--primary);
  background: rgba(46, 107, 255, 0.10);
  border: 1px solid rgba(46, 107, 255, 0.16);
}
.product__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 10px;
  transition: transform 0.35s ease;
}
.product:hover .product__media img { transform: scale(1.05); }

.product__body { padding: 16px 18px 18px; display: flex; flex-direction: column; gap: 8px; flex: 1; }
.product__name { font-size: 15.5px; font-weight: 700; color: var(--ink); }
.product__spec { font-size: 13px; color: var(--muted); line-height: 1.5; flex: 1; }
.product__foot { display: flex; align-items: center; justify-content: space-between; margin-top: 4px; }
.product__cat {
  font-size: 12px;
  color: var(--muted);
  background: var(--bg-soft);
  border-radius: 6px;
  padding: 4px 10px;
}
.product__btn {
  font-size: 13.5px;
  font-weight: 600;
  color: var(--primary);
  background: rgba(46, 107, 255, 0.08);
  border-radius: 999px;
  padding: 7px 14px;
  transition: background 0.2s ease, color 0.2s ease;
}
.product__btn:hover { background: var(--grad); color: #fff; }

.products__note { text-align: center; margin-top: 40px; font-size: 13px; color: var(--muted); }

/* ---------- 定制服务 ---------- */
.custom {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 56px;
  align-items: center;
}
.custom__intro p { margin-bottom: 22px; }
.custom__intro strong { color: var(--primary); }
.custom__list { display: flex; flex-direction: column; gap: 14px; }
.custom__list li {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 18px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.custom__list li:hover { transform: translateX(6px); box-shadow: var(--shadow-sm); }
.custom__list b {
  flex-shrink: 0;
  font-size: 14px;
  color: #fff;
  padding: 6px 14px;
  border-radius: 999px;
  background: var(--grad);
}
.custom__list span { font-size: 14px; color: var(--text); }

.custom__boards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.custom__card {
  border-radius: var(--radius);
  overflow: hidden;
  background: #fff;
  border: 1px solid var(--line);
  box-shadow: var(--shadow-sm);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.custom__card:hover { transform: translateY(-5px); box-shadow: var(--shadow-md); }
.custom__card img { aspect-ratio: 1 / 1; object-fit: cover; }
.custom__card figcaption {
  padding: 12px 14px;
  font-size: 13.5px;
  font-weight: 600;
  color: var(--ink);
  text-align: center;
}

/* 定制流程 */
.steps {
  margin-top: 72px;
  padding: 44px 48px;
  background: linear-gradient(120deg, #0E1A3D, #14265C);
  border-radius: 24px;
  color: #fff;
}
.steps__title {
  font-size: 20px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 36px;
}
.steps__list { display: grid; grid-template-columns: repeat(5, 1fr); gap: 18px; }
.steps__list li {
  position: relative;
  text-align: center;
  padding: 0 8px;
}
.steps__list li:not(:last-child)::after {
  content: "";
  position: absolute;
  top: 24px; right: -10px;
  width: 20px; height: 2px;
  background: linear-gradient(90deg, rgba(18, 201, 240, 0.6), transparent);
}
.steps__list span {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px; height: 48px;
  margin: 0 auto 14px;
  border-radius: 14px;
  font-size: 15px;
  font-weight: 800;
  color: #0E1A3D;
  background: var(--grad);
}
.steps__list b { display: block; font-size: 15px; margin-bottom: 6px; }
.steps__list p { font-size: 12.5px; color: rgba(255, 255, 255, 0.65); }

/* ---------- CTA ---------- */
.cta {
  padding: 90px 0;
  background:
    radial-gradient(700px 300px at 80% 20%, rgba(18, 201, 240, 0.25), transparent 60%),
    linear-gradient(120deg, #2E6BFF, #12C9F0);
}
.cta__inner { text-align: center; color: #fff; }
.cta__title { font-size: clamp(26px, 3.6vw, 38px); font-weight: 800; }
.cta__desc { margin-top: 12px; font-size: 16px; opacity: 0.9; }
.cta .btn { margin-top: 30px; }

/* ---------- 底部 ---------- */
.footer {
  background: var(--navy);
  color: #A7B4D1;
  padding: 64px 0 0;
}
.footer__main {
  display: flex;
  justify-content: space-between;
  gap: 48px;
  flex-wrap: wrap;
  padding-bottom: 44px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}
.footer__brand { max-width: 320px; }
.footer__logo { height: 54px; width: auto; margin-bottom: 18px; filter: brightness(0) invert(1) opacity(0.9); }
.footer__brand p { font-size: 13.5px; line-height: 1.9; }
.footer__links { display: flex; gap: 72px; flex-wrap: wrap; }
.footer__col { display: flex; flex-direction: column; gap: 10px; }
.footer__col b {
  color: #fff;
  font-size: 15px;
  margin-bottom: 6px;
}
.footer__col a, .footer__col span { font-size: 13.5px; transition: color 0.2s ease; }
.footer__col a:hover { color: #fff; }
.footer__bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  padding: 22px 0;
  font-size: 13px;
}
.footer__icp a { color: #A7B4D1; transition: color 0.2s ease; }
.footer__icp a:hover { color: #fff; }

/* ---------- 滚动显现动画 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.is-visible { opacity: 1; transform: none; }

/* ---------- 响应式 ---------- */
@media (max-width: 1080px) {
  .products { grid-template-columns: repeat(3, 1fr); }
  .about__grid, .custom { grid-template-columns: 1fr; gap: 40px; }
  .steps { padding: 36px 28px; }
  .steps__list { grid-template-columns: repeat(5, 1fr); }
}

@media (max-width: 900px) {
  .nav__links {
    position: fixed;
    top: 76px; left: 0; right: 0;
    flex-direction: column;
    gap: 0;
    background: #fff;
    border-bottom: 1px solid var(--line);
    box-shadow: var(--shadow-md);
    padding: 12px 24px 20px;
    transform: translateY(-8px);
    opacity: 0;
    visibility: hidden;
    transition: transform 0.3s ease, opacity 0.3s ease, visibility 0.3s;
  }
  .nav__links.is-open { transform: none; opacity: 1; visibility: visible; }
  .nav__links a { padding: 12px 0; font-size: 16px; width: 100%; }
  .nav__links a::after { display: none; }
  .nav__burger { display: flex; }
  .nav__cta { display: none; }
  .steps__list { grid-template-columns: repeat(2, 1fr); gap: 24px; }
  .steps__list li:nth-child(2n)::after { display: none; }
}

@media (max-width: 720px) {
  .section { padding: 72px 0; }
  .hero { padding: 140px 0 60px; }
  .hero__stats { flex-wrap: wrap; }
  .hero__stat { flex: 1 1 50%; }
  .hero__stat:nth-child(odd) { border-left: none; }
  .hero__stat:nth-child(2) { border-left: 1px solid var(--line); }
  .products { grid-template-columns: repeat(2, 1fr); gap: 14px; }
  .about__features { grid-template-columns: 1fr; }
  .custom__boards { grid-template-columns: 1fr; }
  .footer__links { gap: 40px; }
  .footer__bottom { justify-content: center; text-align: center; }
}

@media (max-width: 480px) {
  .products { grid-template-columns: 1fr 1fr; gap: 10px; }
  .product__body { padding: 12px; }
  .product__name { font-size: 13.5px; }
  .product__spec { font-size: 12px; }
}