/* =========================================================
   SAKAI 酒井工程机械（上海）— 新站样式
   风格参照 sakainet.co.jp：金色 #f9b900 + 深蓝 #14246b
   ========================================================= */
:root {
  --gold: #f9b900;
  --gold-dark: #e0a600;
  --navy: #14246b;
  --navy-dark: #0e1a4f;
  --navy-light: #1e2f7d;
  --gray: #696969;
  --gray-light: #f4f4f4;
  --line: #e5e5e5;
  --text: #2b2b2b;
  --max-w: 1120px;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: "Noto Sans SC", -apple-system, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: #fff;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
.container { max-width: var(--max-w); margin: 0 auto; padding: 0 20px; }

/* ---------- Header ---------- */
.site-header {
  background: var(--navy);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 8px rgba(0,0,0,.15);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
}
.logo { display: flex; align-items: center; gap: 12px; }
.logo-mark {
  background: var(--gold);
  color: var(--navy-dark);
  font-weight: 900;
  font-size: 22px;
  letter-spacing: 1px;
  padding: 4px 12px;
  border-radius: 3px;
  font-family: Arial, sans-serif;
}
.logo-text {
  color: #fff;
  font-size: 17px;
  font-weight: 600;
  letter-spacing: 2px;
}
.main-nav { display: flex; align-items: center; gap: 4px; }
.main-nav a {
  color: rgba(255,255,255,.82);
  font-size: 15px;
  padding: 26px 14px;
  transition: color .2s, background .2s;
  border-bottom: 3px solid transparent;
  letter-spacing: 1px;
}
.main-nav a:hover { color: var(--gold); background: rgba(255,255,255,.06); }
.main-nav a.active {
  color: var(--gold);
  border-bottom-color: var(--gold);
  font-weight: 600;
}
.nav-toggle { display: none; background: none; border: 0; color: #fff; font-size: 24px; cursor: pointer; }
.mobile-nav { display: none; background: var(--navy-dark); flex-direction: column; }
.mobile-nav.open { display: flex; }
.mobile-nav a { color: #fff; padding: 14px 24px; border-top: 1px solid rgba(255,255,255,.08); }

/* ---------- Hero ---------- */
.hero { position: relative; overflow: hidden; }
.hero-slider { display: flex; transition: transform .6s ease; }
.slide { min-width: 100%; }
.slide img { width: 100%; height: 480px; object-fit: cover; }
@media (max-width: 768px) {
  .slide img { height: 260px; }
}

/* ---------- Section ---------- */
.section { padding: 64px 0; }
.bg-gray { background: var(--gray-light); }
.section-head { text-align: center; margin-bottom: 40px; }
.section-head h2 {
  font-size: 30px;
  color: var(--navy);
  font-weight: 800;
  letter-spacing: 2px;
  position: relative;
  padding-bottom: 14px;
  display: inline-block;
}
.section-head h2::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 0;
  transform: translateX(-50%);
  width: 56px;
  height: 4px;
  background: var(--gold);
  border-radius: 2px;
}
.section-head .en {
  font-size: 13px;
  color: var(--gold-dark);
  font-weight: 600;
  letter-spacing: 3px;
  margin-left: 10px;
  vertical-align: middle;
}
.section-head .sub { color: var(--gray); margin-top: 12px; font-size: 15px; }
.section-more { text-align: center; margin-top: 36px; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-block;
  padding: 12px 28px;
  border-radius: 3px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 1px;
  transition: all .2s;
}
.btn-gold { background: var(--gold); color: var(--navy-dark); }
.btn-gold:hover { background: var(--gold-dark); }
.btn-navy { background: var(--navy); color: #fff; }
.btn-navy:hover { background: var(--navy-light); }
.btn-outline { border: 2px solid var(--navy); color: var(--navy); }
.btn-outline:hover { background: var(--navy); color: #fff; }

/* ---------- 公司介绍 ---------- */
.company-box {
  background: #fff;
  border: 1px solid var(--line);
  border-left: 5px solid var(--gold);
  padding: 32px 36px;
  max-width: 860px;
  margin: 0 auto;
  box-shadow: 0 4px 18px rgba(20,36,107,.05);
}
.company-box .lead { font-size: 16px; line-height: 2; color: #444; }
.company-actions { margin-top: 22px; display: flex; gap: 14px; flex-wrap: wrap; }

/* ---------- 产品 ---------- */
.product-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 24px;
}
.product-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 6px;
  overflow: hidden;
  transition: transform .2s, box-shadow .2s, border-color .2s;
}
.product-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 24px rgba(20,36,107,.12);
  border-color: var(--gold);
}
.product-img { background: #fafafa; aspect-ratio: 4/3; display: flex; align-items: center; justify-content: center; }
.product-img img { max-height: 100%; object-fit: contain; padding: 16px; }
.product-name {
  padding: 14px 16px;
  font-weight: 600;
  color: var(--navy);
  text-align: center;
  border-top: 1px solid var(--line);
  font-size: 15px;
}

/* ---------- 新闻列表 ---------- */
.news-list { max-width: 860px; margin: 0 auto; }
.news-item {
  display: flex;
  align-items: center;
  gap: 20px;
  padding: 18px 8px;
  border-bottom: 1px dashed var(--line);
  transition: background .15s;
}
.news-item:hover { background: #fafbff; }
.news-date {
  background: var(--gold);
  color: var(--navy-dark);
  font-weight: 700;
  font-size: 13px;
  padding: 4px 12px;
  border-radius: 3px;
  white-space: nowrap;
  font-family: Arial, sans-serif;
  letter-spacing: .5px;
}
.news-item a { color: var(--text); font-size: 15px; }
.news-item a:hover { color: var(--navy); text-decoration: underline; }
.badge-pdf {
  display: inline-block;
  font-size: 11px;
  background: #eef0f7;
  color: var(--navy);
  border: 1px solid #d4d9ec;
  padding: 1px 7px;
  border-radius: 3px;
  margin-left: 8px;
  vertical-align: middle;
  font-weight: 600;
}

/* ---------- 内页 banner ---------- */
.page-banner {
  background: var(--navy);
  color: #fff;
  padding: 56px 0;
  position: relative;
  overflow: hidden;
}
.page-banner::after {
  content: "";
  position: absolute;
  left: 0; bottom: 0;
  width: 100%;
  height: 5px;
  background: linear-gradient(90deg, var(--gold) 0 40%, transparent 40%);
}
.page-banner h1 { font-size: 32px; font-weight: 800; letter-spacing: 3px; }
.page-banner p { color: var(--gold); letter-spacing: 5px; margin-top: 6px; font-size: 14px; font-weight: 600; }

/* ---------- 正文 ---------- */
.content-body { max-width: 900px; margin: 0 auto; }
.content-body p { margin-bottom: 18px; font-size: 15.5px; line-height: 2; }
.content-body h3 { color: var(--navy); margin: 28px 0 12px; font-size: 19px; padding-left: 12px; border-left: 4px solid var(--gold); }
.content-body img { margin: 20px auto; border-radius: 4px; }

/* ---------- 产品详情 ---------- */
.product-detail { max-width: 900px; margin: 0 auto; }
.product-detail-top { display: grid; grid-template-columns: 1fr 1fr; gap: 36px; align-items: start; margin-bottom: 30px; }
@media (max-width: 768px) { .product-detail-top { grid-template-columns: 1fr; } }
.product-hero { background: #fafafa; border: 1px solid var(--line); border-radius: 8px; padding: 20px; }
.product-hero img { margin: 0 auto; max-height: 320px; object-fit: contain; }
.product-intro p { margin-bottom: 14px; font-size: 15px; line-height: 2; }
.spec-table-wrap { overflow-x: auto; margin: 20px 0 30px; border: 1px solid var(--line); border-radius: 6px; }
.spec-table { width: 100%; border-collapse: collapse; font-size: 14.5px; }
.spec-table th, .spec-table td { padding: 12px 16px; border: 1px solid var(--line); text-align: left; }
.spec-table th { background: var(--navy); color: #fff; font-weight: 600; width: 26%; white-space: nowrap; }
.spec-table tr:nth-child(even) td { background: #f8f9fc; }
.back-link { margin-top: 20px; }
.back-link a { color: var(--navy); font-weight: 600; }
.back-link a:hover { color: var(--gold-dark); }

/* ---------- 视频 ---------- */
.video-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(340px, 1fr)); gap: 24px; }
.video-card { border: 1px solid var(--line); border-radius: 6px; overflow: hidden; background: #fff; }
.video-card video { width: 100%; background: #000; aspect-ratio: 16/9; }
.video-name { padding: 12px 16px; font-weight: 600; color: var(--navy); font-size: 14.5px; }

/* ---------- 联系我们 ---------- */
.contact-info {
  background: var(--gray-light);
  border-left: 5px solid var(--gold);
  padding: 26px 30px;
  margin-top: 24px;
  border-radius: 4px;
}
.contact-info p { margin-bottom: 8px; }
.contact-info a { color: var(--navy); text-decoration: underline; }

/* ---------- Footer ---------- */
.site-footer { background: var(--navy-dark); color: rgba(255,255,255,.82); margin-top: 40px; }
.footer-inner {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.2fr;
  gap: 36px;
  padding: 52px 20px;
}
@media (max-width: 900px) { .footer-inner { grid-template-columns: 1fr 1fr; } }
.footer-logo { font-size: 24px; font-weight: 900; color: #fff; letter-spacing: 1px; }
.footer-logo span { color: var(--gold); }
.footer-brand p { font-size: 12px; color: rgba(255,255,255,.55); margin-top: 10px; letter-spacing: 1px; }
.footer-links h4, .footer-contact h4 {
  color: var(--gold);
  font-size: 15px;
  margin-bottom: 14px;
  letter-spacing: 1px;
}
.footer-links li { margin-bottom: 8px; }
.footer-links a, .footer-contact a { font-size: 13.5px; color: rgba(255,255,255,.78); }
.footer-links a:hover, .footer-contact a:hover { color: var(--gold); }
.footer-contact p { font-size: 13.5px; color: rgba(255,255,255,.78); margin-bottom: 8px; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.1); padding: 18px 0; text-align: center; }
.footer-bottom p { font-size: 13px; color: rgba(255,255,255,.5); letter-spacing: 1px; }

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  .main-nav { display: none; }
  .nav-toggle { display: block; }
  .section { padding: 44px 0; }
  .section-head h2 { font-size: 24px; }
  .news-item { flex-direction: column; align-items: flex-start; gap: 8px; }
  .product-grid { grid-template-columns: repeat(2, 1fr); gap: 14px; }
  .company-actions { flex-direction: column; }
}