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

:root {
  --navy: #0f2b46;
  --navy-2: #16395c;
  --orange: #f26522;
  --orange-dark: #d9531a;
  --bg: #ffffff;
  --bg-alt: #f4f6f9;
  --text: #22303f;
  --muted: #64748b;
  --line: #e2e8f0;
  --radius: 12px;
}

html { scroll-behavior: smooth; }
body {
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
}
.container { max-width: 1160px; margin: 0 auto; padding: 0 20px; }
a { text-decoration: none; color: inherit; }
img { max-width: 100%; display: block; }

/* ===== Top bar ===== */
.topbar { background: var(--navy); color: #cfd9e4; font-size: 13px; }
.topbar-inner { display: flex; justify-content: space-between; align-items: center; height: 38px; }
.lang-switch { display: flex; gap: 4px; }
.lang-btn {
  background: transparent; border: 1px solid rgba(255,255,255,.25); color: #cfd9e4;
  padding: 3px 12px; border-radius: 999px; cursor: pointer; font-size: 12px;
}
.lang-btn:hover { color: #fff; border-color: rgba(255,255,255,.5); }
.lang-btn.active { background: var(--orange); border-color: var(--orange); color: #fff; }

/* ===== Header ===== */
.header {
  position: sticky; top: 0; z-index: 100; background: #fff;
  border-bottom: 1px solid var(--line);
  box-shadow: 0 1px 4px rgba(15,43,70,.05);
}
.header-inner { display: flex; align-items: center; gap: 28px; height: 72px; }
.brand { display: flex; align-items: center; gap: 12px; }
.brand-logo {
  width: 46px; height: 46px; border-radius: 10px; background: linear-gradient(135deg, var(--navy), var(--navy-2));
  color: #fff; display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 17px; letter-spacing: 1px;
}
.brand-text { display: flex; flex-direction: column; line-height: 1.25; }
.brand-name { font-size: 16px; color: var(--navy); }
.brand-sub { font-size: 11px; color: var(--muted); letter-spacing: .5px; text-transform: uppercase; }
.nav { display: flex; gap: 24px; margin-left: auto; }
.nav a { font-size: 15px; color: var(--text); font-weight: 500; position: relative; padding: 6px 0; }
.nav a::after {
  content: ""; position: absolute; left: 0; bottom: 0; width: 0; height: 2px;
  background: var(--orange); transition: width .25s;
}
.nav a:hover::after { width: 100%; }
.nav-cta { margin-left: 8px; }
.menu-toggle { display: none; background: none; border: none; cursor: pointer; margin-left: auto; }
.menu-toggle span { display: block; width: 22px; height: 2px; background: var(--navy); margin: 5px 0; }

/* ===== Buttons ===== */
.btn {
  display: inline-block; padding: 10px 26px; border-radius: 8px;
  font-size: 15px; font-weight: 600; transition: all .2s; border: 1px solid transparent;
}
.btn-primary { background: var(--orange); color: #fff; }
.btn-primary:hover { background: var(--orange-dark); }
.btn-ghost { color: #fff; border-color: rgba(255,255,255,.6); }
.btn-ghost:hover { background: rgba(255,255,255,.12); color: #fff; }
.btn-outline { color: var(--orange); border-color: var(--orange); padding: 8px 20px; font-size: 14px; }
.btn-outline:hover { background: var(--orange); color: #fff; }

/* ===== Hero ===== */
.hero {
  background:
    radial-gradient(circle at 85% 15%, rgba(242,101,34,.28), transparent 45%),
    linear-gradient(115deg, rgba(15,43,70,.92) 0%, rgba(15,43,70,.80) 55%, rgba(22,57,92,.62) 100%),
    url("../images/hero.jpg") center center / cover no-repeat;
  color: #fff; padding: 110px 0 120px;
}
.hero-inner { max-width: 760px; }
.hero-text { max-width: 680px; }
.hero-tag {
  display: inline-block; font-size: 13px; letter-spacing: 1px;
  background: rgba(242,101,34,.18); color: #ffb08a; border: 1px solid rgba(242,101,34,.4);
  padding: 5px 14px; border-radius: 999px; margin-bottom: 20px;
}
.hero h1 { font-size: 44px; line-height: 1.25; margin-bottom: 18px; }
.hero p { color: #b9c7d6; font-size: 16.5px; max-width: 560px; margin-bottom: 30px; }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 40px; }
.hero-stats { display: flex; gap: 36px; flex-wrap: wrap; border-top: 1px solid rgba(255,255,255,.15); padding-top: 26px; }
.stat strong { display: block; font-size: 26px; color: #fff; }
.stat span { font-size: 13px; color: #9fb0c1; }

/* ===== Placeholder ===== */
.ph {
  position: relative; background: #dfe5ec; border: 2px dashed #b6c2d2;
  border-radius: var(--radius); overflow: hidden; display: flex; align-items: center; justify-content: center;
}
.ph img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; z-index: 2; }
.ph-icon { font-size: 52px; opacity: .45; }
.ph-label { position: absolute; bottom: 10px; left: 0; right: 0; text-align: center; font-size: 12px; color: #7d8ea1; z-index: 1; }
.ph-about { width: 100%; aspect-ratio: 16/11; }
/* ===== Sections ===== */
.section { padding: 84px 0; }
.section-alt { background: var(--bg-alt); }
.section-dark { background: var(--navy); color: #fff; }
.section-head { text-align: center; max-width: 680px; margin: 0 auto 52px; }
.section-tag { color: var(--orange); font-size: 13px; font-weight: 700; letter-spacing: 2px; text-transform: uppercase; }
.section-dark .section-tag { color: #ffab7e; }
.section-head h2 { font-size: 32px; color: var(--navy); margin: 10px 0 12px; }
.section-dark .section-head h2 { color: #fff; }
.section-head p { color: var(--muted); }
.section-dark .section-head p { color: #a9b8c8; }

/* ===== Products ===== */
.products-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.product-card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden; transition: transform .25s, box-shadow .25s; display: flex; flex-direction: column;
}
.product-card:hover { transform: translateY(-5px); box-shadow: 0 14px 30px rgba(15,43,70,.12); }
.product-media { position: relative; }
.product-media .ph { border: none; border-radius: 0; aspect-ratio: 4/3; background: #eef1f5; border-bottom: 1px solid var(--line); }
.product-media .ph-label { font-size: 11px; }
.product-media .ph-icon { font-size: 44px; }
.product-tag {
  position: absolute; top: 12px; left: 12px; z-index: 3; background: var(--navy); color: #fff;
  font-size: 11px; padding: 3px 10px; border-radius: 4px; letter-spacing: .5px;
}
.product-body { padding: 20px 22px 24px; display: flex; flex-direction: column; flex: 1; }
.product-body h3 { font-size: 18px; color: var(--navy); margin-bottom: 8px; }
.product-body .product-desc { font-size: 14px; color: var(--muted); margin-bottom: 14px; flex: 1; }
.product-specs { list-style: none; border-top: 1px dashed var(--line); padding-top: 12px; }
.product-specs li { font-size: 13px; color: var(--text); padding: 3px 0; display: flex; gap: 8px; }
.product-specs li::before { content: "▸"; color: var(--orange); font-weight: 700; }

/* ===== Advantages ===== */
.adv-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.adv-card {
  background: #fff; border-radius: var(--radius); padding: 30px 24px;
  border: 1px solid var(--line); transition: transform .25s, box-shadow .25s;
}
.adv-card:hover { transform: translateY(-4px); box-shadow: 0 12px 26px rgba(15,43,70,.1); }
.adv-icon { font-size: 34px; margin-bottom: 14px; }
.adv-card h3 { font-size: 17px; color: var(--navy); margin-bottom: 8px; }
.adv-card p { font-size: 14px; color: var(--muted); }

/* ===== About ===== */
.about-inner { display: grid; grid-template-columns: .9fr 1.1fr; gap: 56px; align-items: center; }
.about-text h2 { font-size: 30px; color: var(--navy); margin: 10px 0 18px; }
.about-text p { color: var(--muted); margin-bottom: 14px; font-size: 15.5px; }
.about-list { list-style: none; margin-top: 18px; }
.about-list li { padding: 8px 0; font-size: 15px; color: var(--text); border-bottom: 1px dashed var(--line); }

/* ===== Contact ===== */
.contact-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; max-width: 940px; margin: 0 auto; }
.contact-card {
  background: rgba(255,255,255,.06); border: 1px solid rgba(255,255,255,.14);
  border-radius: var(--radius); padding: 34px 26px; text-align: center;
}
.contact-icon { font-size: 34px; margin-bottom: 12px; }
.contact-card h3 { font-size: 17px; margin-bottom: 8px; }
.contact-card p { font-size: 16px; color: #ffcf9f; font-weight: 600; }
.contact-card a { color: #ffcf9f; font-weight: 600; text-decoration: underline; text-underline-offset: 3px; }
.contact-card a:hover { color: #fff; }
.contact-note { display: block; margin-top: 8px; font-size: 12px; color: #8fa3b8; }

/* ===== Footer ===== */
.footer { background: #0a1f33; color: #8fa3b8; padding: 26px 0; }
.footer-inner { display: flex; justify-content: space-between; align-items: center; gap: 16px; flex-wrap: wrap; }
.footer-brand strong { color: #fff; display: block; font-size: 15px; }
.footer-brand span { font-size: 12.5px; }
.footer-note { font-size: 12.5px; }

/* ===== Responsive ===== */
@media (max-width: 960px) {
  .about-inner { grid-template-columns: 1fr; gap: 40px; }
  .products-grid { grid-template-columns: repeat(2, 1fr); }
  .adv-grid { grid-template-columns: repeat(2, 1fr); }
  .hero h1 { font-size: 34px; }
  .nav, .nav-cta, .topbar-note { display: none; }
  .menu-toggle { display: block; }
  .nav.open {
    display: flex; flex-direction: column; position: absolute; top: 72px; left: 0; right: 0;
    background: #fff; border-bottom: 1px solid var(--line); padding: 16px 24px; gap: 14px;
    box-shadow: 0 10px 24px rgba(15,43,70,.1);
  }
}
@media (max-width: 620px) {
  .products-grid, .adv-grid, .contact-grid { grid-template-columns: 1fr; }
  .hero { padding: 60px 0 70px; }
  .section { padding: 60px 0; }
  .hero-stats { gap: 22px; }
}