/* ===== Variables ===== */
:root {
  --primary: #1a5fa5;
  --primary-dark: #0c447c;
  --primary-light: #e6f1fb;
  --accent: #378add;
  --text: #2c2c2a;
  --text-light: #666;
  --text-muted: #999;
  --bg: #ffffff;
  --bg-light: #f8f9fa;
  --border: #e0e0e0;
  --border-light: #f0f0f0;
  --white: #ffffff;
  --shadow: 0 2px 8px rgba(0,0,0,0.08);
  --shadow-hover: 0 4px 20px rgba(0,0,0,0.12);
  --radius: 8px;
  --radius-lg: 12px;
  --max-width: 1140px;
}

/* ===== Reset ===== */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
}
a { color: var(--primary); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--primary-dark); }
img { max-width: 100%; height: auto; }
ul { list-style: none; }
h1, h2, h3, h4 { line-height: 1.3; }

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

/* ===== Header ===== */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--white);
  border-bottom: 1px solid var(--border);
}
.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}
.logo { display: flex; align-items: center; font-size: 28px; font-weight: 700; color: var(--primary); letter-spacing: -0.5px; }
.logo img { height: 52px; width: auto; max-width: 220px; display: block; }
.logo span { color: var(--text); font-weight: 400; }
.header-right { display: flex; align-items: center; gap: 40px; margin-left: 80px; }
.nav { display: flex; gap: 36px; }
.nav a {
  color: var(--text);
  font-size: 15px;
  font-weight: 500;
  padding: 6px 0;
  border-bottom: 2px solid transparent;
}
.nav a:hover, .nav a.active { color: var(--primary); border-bottom-color: var(--primary); }
.menu-toggle { display: none; font-size: 24px; background: none; border: none; cursor: pointer; color: var(--text); }
.header-contact { display: flex; align-items: center; gap: 20px; flex-shrink: 0; }
.header-contact-item {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 13px;
  color: var(--text-light);
  white-space: nowrap;
  transition: color 0.2s;
}
.header-contact-item:hover { color: var(--primary); }
.header-contact-item svg { flex-shrink: 0; }

/* ===== Hero ===== */
.hero {
  background: linear-gradient(135deg, rgba(12,68,124,0.85) 0%, rgba(26,95,165,0.80) 50%, rgba(55,138,221,0.75) 100%),
              url('images/hero-banner.png') center center / cover no-repeat;
  color: var(--white);
  padding: 88px 0;
  text-align: center;
}
.hero h1 { font-size: 36px; font-weight: 700; margin-bottom: 16px; }
.hero p { font-size: 17px; opacity: 0.92; max-width: 580px; margin: 0 auto 32px; }

/* ===== Buttons ===== */
.btn {
  display: inline-block;
  padding: 12px 32px;
  border-radius: var(--radius);
  font-size: 15px;
  font-weight: 600;
  text-align: center;
  cursor: pointer;
  border: none;
  transition: all 0.2s;
}
.btn-white { background: var(--white); color: var(--primary); }
.btn-white:hover { background: var(--primary-light); color: var(--primary-dark); }
.btn-blue { background: var(--primary); color: var(--white); }
.btn-blue:hover { background: var(--primary-dark); color: var(--white); }
.btn-outline { background: transparent; color: var(--primary); border: 2px solid var(--primary); }
.btn-outline:hover { background: var(--primary); color: var(--white); }

/* ===== Sections ===== */
.section { padding: 64px 0; }
.section-light { background: var(--bg-light); }
.section-title { text-align: center; font-size: 28px; font-weight: 700; margin-bottom: 8px; }
.section-subtitle { text-align: center; color: var(--text-light); font-size: 16px; margin-bottom: 48px; }

/* ===== Product Grid ===== */
.product-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 24px;
}
.product-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all 0.25s;
}
.product-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-3px);
  border-color: var(--primary);
}
.product-card-banner {
  height: 8px;
}
.product-card-img {
  width: 100%;
  height: 180px;
  object-fit: cover;
  display: block;
  border-bottom: 1px solid var(--border-light);
}
.product-card-body { padding: 20px; }
.product-card-body h3 { font-size: 17px; font-weight: 600; margin-bottom: 4px; }
.product-card-cas { font-size: 13px; color: var(--text-muted); margin-bottom: 10px; font-family: 'Courier New', monospace; }
.product-card-desc { font-size: 13px; color: var(--text-light); margin-bottom: 14px; line-height: 1.5; }
.product-card-link { font-size: 14px; font-weight: 600; color: var(--primary); }
.product-card-link:after { content: ' \2192'; }

/* ===== Advantages ===== */
.advantage-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 32px;
}
.advantage-item {
  text-align: center;
  padding: 24px 16px;
}
.advantage-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 16px;
  border-radius: 50%;
  background: var(--primary-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  font-weight: 700;
  color: var(--primary);
}
.advantage-item h3 { font-size: 17px; font-weight: 600; margin-bottom: 8px; }
.advantage-item p { font-size: 14px; color: var(--text-light); }

/* ===== CTA Section ===== */
.cta-section {
  background: var(--primary);
  color: var(--white);
  text-align: center;
  padding: 56px 0;
}
.cta-section h2 { font-size: 26px; font-weight: 700; margin-bottom: 12px; }
.cta-section p { font-size: 16px; opacity: 0.9; margin-bottom: 28px; }

/* ===== Footer ===== */
.footer {
  background: #1a1a2e;
  color: #b0b0b0;
  padding: 48px 0 24px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 32px;
}
.footer h4 { color: var(--white); font-size: 15px; font-weight: 600; margin-bottom: 14px; }
.footer p, .footer a { font-size: 14px; color: #b0b0b0; line-height: 1.8; }
.footer a:hover { color: var(--white); }
.footer-bottom {
  border-top: 1px solid #2a2a3e;
  padding-top: 20px;
  text-align: center;
  font-size: 13px;
  color: #666;
}

/* ===== Breadcrumb ===== */
.breadcrumb {
  background: var(--bg-light);
  padding: 14px 0;
  font-size: 14px;
  border-bottom: 1px solid var(--border-light);
}
.breadcrumb a { color: var(--text-light); }
.breadcrumb a:hover { color: var(--primary); }
.breadcrumb .sep { margin: 0 8px; color: var(--text-muted); }
.breadcrumb .current { color: var(--text); font-weight: 500; }

/* ===== Product Detail ===== */
.product-detail { padding: 48px 0; }
.product-detail h1 { font-size: 28px; font-weight: 700; margin-bottom: 6px; }

/* Product Image */
.product-image-wrap {
  margin-bottom: 32px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--border);
  background: var(--bg-light);
}
.product-image-wrap img {
  width: 100%;
  display: block;
  aspect-ratio: 16/9;
  object-fit: cover;
}
.product-cas-tag {
  display: inline-block;
  background: var(--primary-light);
  color: var(--primary-dark);
  padding: 4px 12px;
  border-radius: 4px;
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 8px;
  font-family: 'Courier New', monospace;
}
.product-hazard-tag {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 4px;
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 24px;
  margin-left: 8px;
}
.tag-danger { background: #fcebeb; color: #a32d2d; }
.tag-normal { background: #eaf3de; color: #3b6d11; }
.product-content {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 40px;
}
.product-section { margin-bottom: 32px; }
.product-section h2 {
  font-size: 19px;
  font-weight: 600;
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--border-light);
}
.product-section p, .product-section li { font-size: 15px; color: var(--text-light); margin-bottom: 6px; }
.product-section ul { list-style: disc; padding-left: 20px; }

.spec-table { width: 100%; border-collapse: collapse; }
.spec-table td {
  padding: 10px 16px;
  border-bottom: 1px solid var(--border-light);
  font-size: 14px;
}
.spec-table td:first-child { font-weight: 600; width: 40%; color: var(--text); }
.spec-table td:last-child { color: var(--text-light); }

.sidebar-card {
  background: var(--bg-light);
  border-radius: var(--radius-lg);
  padding: 24px;
  margin-bottom: 20px;
}
.sidebar-card h3 { font-size: 16px; font-weight: 600; margin-bottom: 14px; }
.sidebar-card .btn { width: 100%; margin-bottom: 8px; }
.sidebar-info { font-size: 14px; color: var(--text-light); line-height: 1.8; }
.sidebar-info strong { color: var(--text); }

.related-list li { padding: 8px 0; border-bottom: 1px solid var(--border-light); }
.related-list a { font-size: 14px; }

/* ===== About Page ===== */
.about-hero { background: linear-gradient(135deg, #0c447c, #1a5fa5); color: var(--white); padding: 56px 0; text-align: center; }
.about-hero h1 { font-size: 32px; font-weight: 700; margin-bottom: 12px; }
.about-content { padding: 56px 0; }
.about-content p { font-size: 16px; color: var(--text-light); margin-bottom: 16px; }
.about-stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 24px; margin: 40px 0; }
.stat-box { text-align: center; padding: 24px; background: var(--bg-light); border-radius: var(--radius-lg); }
.stat-num { font-size: 32px; font-weight: 700; color: var(--primary); }
.stat-label { font-size: 14px; color: var(--text-light); margin-top: 4px; }

/* ===== Contact Page ===== */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; padding: 56px 0; }
.contact-info h2 { font-size: 22px; font-weight: 600; margin-bottom: 20px; }
.contact-info-item { display: flex; gap: 12px; margin-bottom: 20px; }
.contact-info-icon { width: 40px; height: 40px; border-radius: 8px; background: var(--primary-light); display: flex; align-items: center; justify-content: center; font-size: 18px; flex-shrink: 0; }
.contact-info-text h4 { font-size: 14px; font-weight: 600; margin-bottom: 2px; }
.contact-info-text p { font-size: 14px; color: var(--text-light); }

.contact-form-wrap { background: var(--bg-light); border-radius: var(--radius-lg); padding: 32px; }
.contact-form-wrap h2 { font-size: 22px; font-weight: 600; margin-bottom: 20px; }
.form-group { margin-bottom: 18px; }
.form-group label { display: block; font-size: 14px; font-weight: 600; margin-bottom: 6px; }
.form-group input, .form-group textarea, .form-group select {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 15px;
  font-family: inherit;
  background: var(--white);
}
.form-group input:focus, .form-group textarea:focus, .form-group select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(26,95,165,0.1);
}
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }

/* ===== FAQ Section ===== */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
  background: var(--bg-light);
  border-radius: var(--radius);
  margin-bottom: 12px;
  overflow: hidden;
  border: 1px solid var(--border-light);
}
.faq-item summary {
  padding: 18px 24px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text);
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: '+';
  font-size: 22px;
  font-weight: 400;
  color: var(--primary);
  transition: transform 0.2s;
}
.faq-item[open] summary::after { transform: rotate(45deg); }
.faq-item[open] summary { border-bottom: 1px solid var(--border-light); }
.faq-item p {
  padding: 16px 24px;
  font-size: 15px;
  color: var(--text-light);
  line-height: 1.7;
  margin: 0;
}

/* ===== Breadcrumb Navigation ===== */
.breadcrumb-nav {
  background: var(--bg-light);
  padding: 12px 0;
  font-size: 13px;
  color: var(--text-light);
  border-bottom: 1px solid var(--border-light);
}
.breadcrumb-nav a { color: var(--primary); text-decoration: none; }
.breadcrumb-nav a:hover { text-decoration: underline; }
.breadcrumb-nav span { color: var(--text); }

/* ===== Article Pages ===== */
.article-wrap {
  max-width: 820px;
  margin: 0 auto;
  padding: 48px 0;
}
.article-meta {
  display: flex;
  gap: 16px;
  align-items: center;
  margin-bottom: 16px;
  font-size: 13px;
  color: var(--text-light);
}
.article-category {
  display: inline-block;
  background: var(--primary-light);
  color: var(--primary);
  padding: 4px 12px;
  border-radius: 20px;
  font-weight: 600;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.article-title {
  font-size: 32px;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 32px;
  color: var(--text);
}
.article-body h2 {
  font-size: 24px;
  font-weight: 700;
  margin: 36px 0 16px;
  color: var(--text);
}
.article-body h3 {
  font-size: 18px;
  font-weight: 600;
  margin: 24px 0 12px;
  color: var(--text);
}
.article-body p {
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-light);
  margin-bottom: 16px;
}
.article-body ul, .article-body ol {
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-light);
  margin-bottom: 16px;
  padding-left: 24px;
}
.article-body li { margin-bottom: 8px; }
.article-body strong { color: var(--text); font-weight: 600; }
.article-body a { color: var(--primary); text-decoration: underline; }

.article-table {
  width: 100%;
  border-collapse: collapse;
  margin: 20px 0 28px;
  font-size: 14px;
}
.article-table th {
  background: var(--primary);
  color: var(--white);
  padding: 12px 16px;
  text-align: left;
  font-weight: 600;
}
.article-table td {
  padding: 10px 16px;
  border-bottom: 1px solid var(--border-light);
  color: var(--text-light);
}
.article-table tr:nth-child(even) td { background: var(--bg-light); }

.warning-box {
  background: #fff8e1;
  border: 1px solid #ffe082;
  border-left: 4px solid #ffa000;
  border-radius: var(--radius);
  padding: 20px 24px;
  margin: 20px 0 28px;
}
.warning-box p, .warning-box ul { font-size: 14px; line-height: 1.7; color: #5d4037; }
.warning-box strong { color: #e65100; }
.warning-box ul { padding-left: 20px; margin-bottom: 8px; }

.article-cta {
  background: linear-gradient(135deg, #0c447c, #1a5fa5);
  border-radius: var(--radius-lg);
  padding: 32px;
  margin: 40px 0;
  text-align: center;
}
.article-cta h3 { color: var(--white); font-size: 22px; font-weight: 700; margin-bottom: 12px; }
.article-cta p { color: rgba(255,255,255,0.85); font-size: 15px; margin-bottom: 20px; }
.article-cta .btn { margin: 0 6px 8px; }

.article-related { margin-top: 40px; padding-top: 32px; border-top: 2px solid var(--border-light); }
.article-related h3 { font-size: 20px; font-weight: 700; margin-bottom: 20px; color: var(--text); }
.related-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.related-card {
  display: block;
  background: var(--bg-light);
  border-radius: var(--radius);
  padding: 20px;
  text-decoration: none;
  border: 1px solid var(--border-light);
  transition: box-shadow 0.2s, border-color 0.2s;
}
.related-card:hover { box-shadow: 0 4px 12px rgba(0,0,0,0.08); border-color: var(--primary); }
.related-tag {
  display: inline-block;
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--primary);
  margin-bottom: 8px;
}
.related-card h4 { font-size: 15px; font-weight: 600; color: var(--text); line-height: 1.4; }

/* ===== News Index Page ===== */
.news-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(340px, 1fr)); gap: 28px; margin-top: 40px; }
.news-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--border-light);
  box-shadow: 0 2px 8px rgba(0,0,0,0.06);
  transition: box-shadow 0.2s, transform 0.2s;
}
.news-card:hover { box-shadow: 0 8px 24px rgba(0,0,0,0.12); transform: translateY(-2px); }
.news-card-banner { height: 8px; }
.news-card-body { padding: 24px; }
.news-card-tag {
  display: inline-block;
  background: var(--primary-light);
  color: var(--primary);
  padding: 3px 10px;
  border-radius: 20px;
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 12px;
}
.news-card-body h3 { font-size: 17px; font-weight: 700; line-height: 1.4; margin-bottom: 10px; }
.news-card-body h3 a { color: var(--text); text-decoration: none; }
.news-card-body h3 a:hover { color: var(--primary); }
.news-card-body p { font-size: 14px; color: var(--text-light); line-height: 1.6; margin-bottom: 14px; }
.news-card-meta { font-size: 13px; color: var(--text-light); display: flex; gap: 8px; align-items: center; margin-bottom: 14px; }
.news-card-link { font-size: 14px; font-weight: 600; color: var(--primary); text-decoration: none; }
.news-card-link:hover { text-decoration: underline; }

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .nav { display: none; position: absolute; top: 72px; left: 0; right: 0; background: var(--white); flex-direction: column; padding: 16px 24px; border-bottom: 1px solid var(--border); gap: 0; }
  .nav.open { display: flex; }
  .nav a { padding: 12px 0; border-bottom: 1px solid var(--border-light); }
  .menu-toggle { display: block; }
  .header-contact { display: none; }
  .hero h1 { font-size: 26px; }
  .hero p { font-size: 15px; }
  .section { padding: 40px 0; }
  .section-title { font-size: 22px; }
  .product-content { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 24px; }
  .contact-grid { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .about-stats { grid-template-columns: repeat(2, 1fr); }
  .article-title { font-size: 24px; }
  .article-body h2 { font-size: 20px; }
  .related-grid { grid-template-columns: 1fr; }
  .news-grid { grid-template-columns: 1fr; }
  .article-table { font-size: 13px; }
  .article-table th, .article-table td { padding: 8px 10px; }
}