/* ===== 基础变量 ===== */
:root {
  --c-primary: #1a1a1a;
  --c-primary-light: #333333;
  --c-primary-lighter: #4a4a4a;
  --c-accent: #c9a962;
  --c-accent-light: #d8bd7a;
  --c-accent-dark: #a88b4a;
  --c-bg: #ffffff;
  --c-bg-alt: #f7f7f7;
  --c-bg-dark: #1a1a1a;
  --c-text: #1a1a1a;
  --c-text-secondary: #666666;
  --c-text-light: #999999;
  --c-border: #e8e8e8;
  --c-white: #ffffff;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 3px rgba(26,26,26,0.06);
  --shadow-md: 0 4px 16px rgba(26,26,26,0.08);
  --shadow-lg: 0 12px 40px rgba(26,26,26,0.12);
  --transition: 0.3s ease;
  --container-max: 1200px;
}

/* ===== Reset ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", system-ui, sans-serif;
  color: var(--c-text);
  background: var(--c-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
a { text-decoration: none; color: inherit; }
img { max-width: 100%; display: block; }
ul { list-style: none; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }
input, textarea, select { font-family: inherit; font-size: 14px; }

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

/* ===== 导航栏 ===== */
.header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(255,255,255,0.96);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--c-border);
  transition: var(--transition);
}
.header.scrolled { box-shadow: var(--shadow-sm); }
.nav-wrap {
  display: flex; align-items: center; justify-content: space-between;
  height: 70px;
}
.logo { display: flex; align-items: center; }
.logo-img { height: 44px; width: auto; display: block; }
.nav { display: flex; gap: 32px; }
.nav-link {
  font-size: 15px; color: var(--c-text); font-weight: 500;
  position: relative; padding: 4px 0; transition: var(--transition);
  display: flex; flex-direction: column; align-items: center; gap: 1px; line-height: 1.15;
}
.nav-en {
  font-size: 10px; font-weight: 400; letter-spacing: 1.6px;
  color: var(--c-accent-dark); opacity: 0.85;
  text-transform: uppercase; white-space: nowrap;
}
.nav-link::after {
  content: ''; position: absolute; bottom: -2px; left: 0;
  width: 0; height: 2px; background: var(--c-accent);
  transition: width 0.3s ease;
}
.nav-link:hover { color: var(--c-accent); }
.nav-link:hover::after { width: 100%; }
.nav-link.active { color: var(--c-accent); }
.nav-link.active::after { width: 100%; }

.menu-toggle { display: none; flex-direction: column; gap: 5px; padding: 8px; }
.menu-toggle span {
  width: 22px; height: 2px; background: var(--c-primary);
  transition: var(--transition); border-radius: 2px;
}
.menu-toggle.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.menu-toggle.active span:nth-child(2) { opacity: 0; }
.menu-toggle.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ===== Hero ===== */
.hero {
  position: relative; min-height: 100vh; display: flex; align-items: center;
  background: linear-gradient(135deg, #111111 0%, #1a1a1a 50%, #2a2a2a 100%);
  color: var(--c-white);
  overflow: hidden;
}
.hero-overlay {
  position: absolute; inset: 0;
  background:
    radial-gradient(circle at 25% 30%, rgba(201,169,98,0.12) 0%, transparent 45%),
    radial-gradient(circle at 75% 70%, rgba(201,169,98,0.08) 0%, transparent 45%);
}
.hero::before {
  content: ''; position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.015) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.015) 1px, transparent 1px);
  background-size: 50px 50px;
}
.hero-content {
  position: relative; z-index: 2; padding-top: 70px;
  max-width: var(--container-max);
}
.hero-tag {
  display: inline-block; font-size: 14px; letter-spacing: 2px;
  color: var(--c-accent-light); margin-bottom: 20px;
  padding: 6px 16px; border: 1px solid rgba(201,169,98,0.4);
  border-radius: 30px; width: fit-content;
}
.hero-title {
  font-size: 48px; font-weight: 700; line-height: 1.3;
  margin-bottom: 20px; letter-spacing: 1px;
}
.text-accent {
  background: linear-gradient(90deg, #c9a962, #d8bd7a);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero-desc {
  font-size: 17px; color: rgba(255,255,255,0.72);
  margin-bottom: 36px; line-height: 1.8;
}
.hero-actions { display: flex; gap: 16px; margin-bottom: 60px; }
.hero-stats {
  display: flex; gap: 48px; flex-wrap: wrap;
  padding-top: 36px; border-top: 1px solid rgba(255,255,255,0.1);
}
.stat-item { display: flex; flex-direction: column; gap: 4px; }
.stat-num {
  font-size: 36px; font-weight: 700; color: var(--c-white);
  line-height: 1;
}
.stat-label { font-size: 14px; color: rgba(255,255,255,0.55); }
.scroll-hint {
  position: absolute; bottom: 30px; left: 50%;
  transform: translateX(-50%); color: rgba(255,255,255,0.35);
  animation: bounce 2s infinite;
}
@keyframes bounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(8px); }
}

/* ===== 按钮 ===== */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 12px 32px; font-size: 15px; font-weight: 500;
  border-radius: var(--radius-sm); transition: var(--transition);
  border: 1.5px solid transparent; cursor: pointer;
}
.btn-primary {
  background: var(--c-accent); color: var(--c-white);
  border-color: var(--c-accent);
}
.btn-primary:hover {
  background: var(--c-accent-dark); border-color: var(--c-accent-dark);
  transform: translateY(-2px); box-shadow: var(--shadow-md);
}
.btn-outline {
  background: transparent; color: var(--c-white);
  border-color: rgba(255,255,255,0.3);
}
.btn-outline:hover { border-color: var(--c-white); transform: translateY(-2px); }
.btn-block { width: 100%; }

/* ===== 通用 section ===== */
.section { padding: 100px 0; }
.section-alt { background: var(--c-bg-alt); }
.section-head { text-align: center; margin-bottom: 60px; }
.section-tag {
  display: inline-block; font-size: 13px; letter-spacing: 3px;
  color: var(--c-accent); font-weight: 600; margin-bottom: 12px;
}
.section-title {
  font-size: 32px; font-weight: 700; color: var(--c-primary);
  margin-bottom: 12px;
}
.section-subtitle { font-size: 16px; color: var(--c-text-secondary); }

/* ===== 关于我们 ===== */
.about-grid {
  display: grid; grid-template-columns: 1.3fr 1fr; gap: 60px;
  align-items: start;
}
.about-text p {
  font-size: 15px; color: var(--c-text-secondary);
  margin-bottom: 16px; line-height: 2;
}
.about-features {
  display: grid; grid-template-columns: 1fr 1fr; gap: 16px;
  margin-top: 28px;
}
.about-feature {
  display: flex; align-items: center; gap: 10px;
  padding: 12px 16px; background: var(--c-bg-alt);
  border-radius: var(--radius-sm); font-size: 14px; font-weight: 500;
  color: var(--c-text);
}
.about-cards {
  display: grid; grid-template-columns: 1fr 1fr; gap: 20px;
}
.about-card {
  text-align: center; padding: 36px 20px;
  background: var(--c-primary); border-radius: var(--radius-md);
  color: var(--c-white);
}
.about-card:nth-child(2) { background: var(--c-primary-light); }
.about-card:nth-child(3) { background: var(--c-accent-dark); }
.about-card:nth-child(4) { background: var(--c-primary-light); }
.about-card-num { font-size: 36px; font-weight: 700; line-height: 1; }
.about-card-label { font-size: 14px; opacity: 0.9; margin-top: 8px; }

/* ===== 产品中心 ===== */
.product-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px;
}
.product-card {
  background: var(--c-white); border-radius: var(--radius-md);
  overflow: hidden; border: 1px solid var(--c-border);
  transition: var(--transition); display: flex; flex-direction: column;
}
.product-card:hover {
  box-shadow: var(--shadow-lg); transform: translateY(-6px);
  border-color: transparent;
}
.product-img {
  height: 180px; width: 100%; display: block; object-fit: cover;
}
.product-body { padding: 22px; flex: 1; display: flex; flex-direction: column; }
.product-name {
  font-size: 18px; font-weight: 600; color: var(--c-primary);
  margin-bottom: 10px;
}
.product-desc {
  font-size: 13.5px; color: var(--c-text-secondary); line-height: 1.8;
  margin-bottom: 14px; flex: 1;
}
.product-specs {
  margin-bottom: 14px; padding: 10px 0;
  border-top: 1px solid var(--c-border); border-bottom: 1px solid var(--c-border);
}
.product-specs li {
  font-size: 12.5px; color: var(--c-text-secondary); padding: 2px 0;
  display: flex; align-items: center; gap: 6px;
}
.product-specs li::before {
  content: ''; width: 4px; height: 4px; border-radius: 50%;
  background: var(--c-accent);
}
.product-link {
  font-size: 14px; color: var(--c-accent); font-weight: 500;
  transition: var(--transition);
}
.product-link:hover { color: var(--c-primary); }
.product-card-cta {
  background: linear-gradient(135deg, var(--c-primary), var(--c-primary-light));
  border: none; color: var(--c-white);
}
.product-card-cta .product-name { color: var(--c-white); }
.product-card-cta .product-desc { color: rgba(255,255,255,0.8); }
.product-card-cta .btn-primary {
  background: var(--c-white); color: var(--c-primary); border-color: var(--c-white);
}
.product-card-cta .btn-primary:hover {
  background: var(--c-accent); border-color: var(--c-accent); color: var(--c-white);
}

/* ===== 核心优势 ===== */
.advantage-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 30px;
  margin-bottom: 50px;
}
.advantage-card {
  text-align: center; padding: 40px 24px;
  background: var(--c-white); border-radius: var(--radius-md);
  border: 1px solid var(--c-border); transition: var(--transition);
}
.advantage-card:hover {
  box-shadow: var(--shadow-md); transform: translateY(-4px);
  border-color: var(--c-accent);
}
.advantage-icon {
  width: 64px; height: 64px; margin: 0 auto 20px;
  display: flex; align-items: center; justify-content: center;
  background: rgba(201,169,98,0.1); border-radius: 50%;
}
.advantage-title {
  font-size: 18px; font-weight: 600; color: var(--c-primary);
  margin-bottom: 12px;
}
.advantage-desc {
  font-size: 14px; color: var(--c-text-secondary); line-height: 1.8;
}
.advantage-banner {
  background: linear-gradient(135deg, var(--c-primary), var(--c-primary-light));
  border-radius: var(--radius-md); padding: 36px 40px;
  text-align: center; color: var(--c-white);
}
.advantage-banner-text h3 { font-size: 22px; margin-bottom: 10px; }
.advantage-banner-text p { font-size: 16px; opacity: 0.85; letter-spacing: 1px; }

/* ===== 成功案例 ===== */
.case-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px;
}
.case-card {
  background: var(--c-white); border-radius: var(--radius-md);
  overflow: hidden; border: 1px solid var(--c-border);
  transition: var(--transition);
}
.case-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); }
.case-img { height: 180px; display: flex; align-items: center; justify-content: center; }
.case-body { padding: 24px; }
.case-tag {
  display: inline-block; font-size: 12px; font-weight: 600;
  color: var(--c-accent); background: rgba(201,169,98,0.1);
  padding: 3px 12px; border-radius: 20px; margin-bottom: 12px;
}
.case-title {
  font-size: 17px; font-weight: 600; color: var(--c-primary);
  margin-bottom: 10px; line-height: 1.5;
}
.case-desc {
  font-size: 14px; color: var(--c-text-secondary); line-height: 1.8;
  margin-bottom: 16px;
}
.case-meta {
  display: flex; flex-wrap: wrap; gap: 16px;
  padding-top: 12px; border-top: 1px solid var(--c-border);
}
.case-meta span {
  font-size: 13px; color: var(--c-text-light);
  display: flex; align-items: center; gap: 4px;
}
.case-meta span::before {
  content: ''; width: 4px; height: 4px; border-radius: 50%;
  background: var(--c-accent);
}

/* ===== 新闻动态 ===== */
.news-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px;
}
.news-card {
  display: flex; gap: 20px; padding: 28px;
  background: var(--c-white); border-radius: var(--radius-md);
  border: 1px solid var(--c-border); transition: var(--transition);
}
.news-card:hover { box-shadow: var(--shadow-md); transform: translateY(-4px); }
.news-date {
  font-size: 14px; color: var(--c-accent); font-weight: 600;
  white-space: nowrap; padding-right: 20px;
  border-right: 2px solid var(--c-border);
}
.news-body { flex: 1; }
.news-cat {
  font-size: 12px; color: var(--c-text-light); margin-bottom: 6px; display: block;
}
.news-title {
  font-size: 16px; font-weight: 600; color: var(--c-primary);
  margin-bottom: 8px; line-height: 1.5;
}
.news-excerpt {
  font-size: 13px; color: var(--c-text-secondary); line-height: 1.7;
  margin-bottom: 12px;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical;
  overflow: hidden;
}
.news-link { font-size: 14px; color: var(--c-accent); }
.news-link:hover { color: var(--c-primary); }

/* ===== 联系我们 ===== */
.contact-grid {
  display: grid; grid-template-columns: 1fr 1.2fr; gap: 50px;
}
.contact-info-title {
  font-size: 22px; font-weight: 600; color: var(--c-primary);
  margin-bottom: 28px;
}
.contact-item {
  display: flex; align-items: flex-start; gap: 14px;
  margin-bottom: 22px;
}
.contact-item svg { flex-shrink: 0; margin-top: 2px; }
.contact-label { display: block; font-size: 13px; color: var(--c-text-light); margin-bottom: 4px; }
.contact-value { font-size: 15px; color: var(--c-text); font-weight: 500; }
.contact-qr {
  margin-top: 32px; display: flex; flex-direction: column;
  align-items: center; gap: 10px;
}
.qr-placeholder {
  width: 130px; height: 130px; background: var(--c-white);
  border: 1px solid var(--c-border); border-radius: var(--radius-sm);
  display: flex; align-items: center; justify-content: center;
  overflow: hidden;
}
.qr-img { width: 100%; height: 100%; object-fit: cover; display: block; }
.qr-label { font-size: 13px; color: var(--c-text-secondary); }

.contact-form-wrap {
  background: var(--c-white); border-radius: var(--radius-md);
  padding: 36px; border: 1px solid var(--c-border);
}
.contact-form-title { font-size: 20px; font-weight: 600; color: var(--c-primary); }
.contact-form-hint { font-size: 14px; color: var(--c-text-secondary); margin: 8px 0 24px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.form-group { margin-bottom: 20px; }
.form-group label {
  display: block; font-size: 14px; font-weight: 500;
  color: var(--c-text); margin-bottom: 8px;
}
.form-group input, .form-group textarea, .form-group select {
  width: 100%; padding: 11px 14px;
  border: 1px solid var(--c-border); border-radius: var(--radius-sm);
  color: var(--c-text); transition: var(--transition);
  background: var(--c-bg);
}
.form-group input:focus, .form-group textarea:focus, .form-group select:focus {
  outline: none; border-color: var(--c-accent);
  box-shadow: 0 0 0 3px rgba(201,169,98,0.12);
}
.form-group textarea { resize: vertical; }
.form-success {
  display: none; text-align: center; color: #1d9e75;
  font-size: 14px; margin-top: 16px; font-weight: 500;
}
.form-success.show { display: block; }

/* ===== 页脚 ===== */
.footer {
  background: var(--c-bg-dark); color: rgba(255,255,255,0.7);
  padding: 60px 0 0;
}
.footer-grid {
  display: grid; grid-template-columns: 1.5fr 1fr 1fr 1.3fr;
  gap: 40px; padding-bottom: 50px;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}
.footer-brand .logo { margin-bottom: 16px; }
.logo-img-footer {
  height: 52px; width: auto; display: block;
  background: var(--c-white); padding: 8px; border-radius: 8px;
}
.footer-desc {
  font-size: 14px; line-height: 1.8; max-width: 280px;
}
.footer-title {
  font-size: 16px; font-weight: 600; color: var(--c-white);
  margin-bottom: 18px;
}
.footer-col a {
  display: block; font-size: 14px; color: rgba(255,255,255,0.6);
  margin-bottom: 10px; transition: var(--transition);
}
.footer-col a:hover { color: var(--c-accent-light); }
.footer-col p { font-size: 14px; margin-bottom: 10px; }
.footer-bottom { padding: 20px 0; }
.footer-bottom .container {
  display: flex; justify-content: space-between;
  flex-wrap: wrap; gap: 10px;
}
.footer-bottom span { font-size: 13px; color: rgba(255,255,255,0.4); }

/* ===== 回到顶部 ===== */
.back-to-top {
  position: fixed; bottom: 30px; right: 30px; z-index: 99;
  width: 48px; height: 48px; border-radius: 50%;
  background: var(--c-primary); color: var(--c-white);
  display: flex; align-items: center; justify-content: center;
  opacity: 0; pointer-events: none; transition: var(--transition);
  box-shadow: var(--shadow-md);
}
.back-to-top.show { opacity: 1; pointer-events: auto; }
.back-to-top:hover { background: var(--c-accent); transform: translateY(-3px); }

/* ===== 滚动动画 ===== */
.animate-up { opacity: 0; transform: translateY(30px); animation: fadeUp 0.8s ease forwards; }
.animate-up:nth-child(1) { animation-delay: 0.1s; }
.animate-up:nth-child(2) { animation-delay: 0.25s; }
.animate-up:nth-child(3) { animation-delay: 0.4s; }
.animate-up:nth-child(4) { animation-delay: 0.55s; }
.animate-up:nth-child(5) { animation-delay: 0.7s; }
@keyframes fadeUp { to { opacity: 1; transform: translateY(0); } }

.reveal {
  opacity: 0; transform: translateY(40px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.visible { opacity: 1; transform: translateY(0); }

/* ===== 响应式 ===== */
@media (max-width: 1200px) {
  .product-grid { grid-template-columns: repeat(3, 1fr); }
}
@media (max-width: 1024px) {
  .hero-title { font-size: 36px; }
  .product-grid { grid-template-columns: repeat(2, 1fr); }
  .advantage-grid { grid-template-columns: repeat(2, 1fr); }
  .case-grid, .news-grid { grid-template-columns: 1fr; }
  .about-grid { grid-template-columns: 1fr; gap: 40px; }
  .contact-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
  .nav {
    position: fixed; top: 70px; left: 0; right: 0;
    background: var(--c-white); flex-direction: column;
    gap: 0; padding: 0; max-height: 0; overflow: hidden;
    transition: max-height 0.35s ease; border-bottom: 1px solid var(--c-border);
  }
  .nav.open { max-height: 560px; }
  .nav-link {
    padding: 12px 24px; border-bottom: 1px solid var(--c-border);
    flex-direction: row; align-items: baseline; gap: 10px;
  }
  .nav-link .nav-en { font-size: 11px; letter-spacing: 1.2px; }
  .menu-toggle { display: flex; }
  .logo-img { height: 36px; }
  .logo-img-footer { height: 44px; }
  .hero-title { font-size: 28px; line-height: 1.4; }
  .hero-desc { font-size: 15px; }
  .hero-stats { gap: 24px; }
  .stat-num { font-size: 28px; }
  .section { padding: 60px 0; }
  .section-title { font-size: 24px; }
  .product-grid { grid-template-columns: 1fr; }
  .advantage-grid { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .about-cards { grid-template-columns: 1fr 1fr; }
  .about-features { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-bottom .container { flex-direction: column; text-align: center; }
  .back-to-top { bottom: 20px; right: 20px; width: 42px; height: 42px; }
}