/* ============================================================
   Guangtuo FRP Grating — main stylesheet
   Mobile-first. Palette: deep steel blue + charcoal,
   amber/orange accent. NO large indigo / purple areas.
   ============================================================ */

*,
*::before,
*::after { box-sizing: border-box; }

:root {
  --gt-steel: #1f4e79;
  --gt-steel-dark: #163a5a;
  --gt-steel-soft: #e7eef5;
  --gt-charcoal: #2b2f36;
  --gt-accent: #d9822b;
  --gt-accent-dark: #b56a1f;
  --gt-bg: #f4f6f8;
  --gt-surface: #ffffff;
  --gt-text: #2b2f36;
  --gt-text-soft: #5a6470;
  --gt-line: #d8dee5;
  --gt-radius: 6px;
  --gt-container: 1140px;
}

html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", Roboto, Arial, sans-serif;
  color: var(--gt-text);
  background: var(--gt-bg);
  line-height: 1.65;
  font-size: 16px;
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--gt-steel); text-decoration: none; }
a:hover { color: var(--gt-accent-dark); }

.container {
  max-width: var(--gt-container);
  margin: 0 auto;
  padding: 0 16px;
}
.container-narrow { max-width: 820px; }
.center { text-align: center; }

.screen-reader-text {
  position: absolute; width: 1px; height: 1px;
  overflow: hidden; clip: rect(0 0 0 0);
}

.skip-link {
  position: absolute; top: -40px; left: 8px;
  background: var(--gt-steel); color: #fff;
  padding: 8px 12px; z-index: 999;
}
.skip-link:focus { top: 0; }

/* ---------------- Header ---------------- */
.site-header {
  background: var(--gt-steel-dark);
  color: #fff;
  position: sticky; top: 0; z-index: 50;
  border-bottom: 3px solid var(--gt-accent);
}
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  padding: 12px 16px; gap: 16px;
}
.brand-text { color: #fff; display: block; }
.brand-name { font-size: 1.15rem; font-weight: 700; display: block; }
.brand-tagline { font-size: 0.75rem; opacity: 0.85; display: block; }

.primary-nav { display: none; }
.primary-nav.open { display: block; }
.primary-nav .menu {
  list-style: none; margin: 0; padding: 0;
  display: flex; flex-direction: column; gap: 4px;
}
.primary-nav .menu a {
  color: #fff; padding: 10px 12px; display: block;
  border-radius: var(--gt-radius);
}
.primary-nav .menu a:hover { background: var(--gt-steel); }
.header-rfq {
  display: inline-block; margin: 10px 0;
  background: var(--gt-accent); color: #fff !important;
  padding: 8px 14px; border-radius: var(--gt-radius);
  font-weight: 600;
}

.nav-toggle {
  background: transparent; border: 1px solid rgba(255,255,255,0.4);
  padding: 8px; border-radius: var(--gt-radius); cursor: pointer;
}
.nav-toggle-bar { display: block; width: 22px; height: 2px; background: #fff; margin: 4px 0; }

@media (min-width: 900px) {
  .nav-toggle { display: none; }
  .primary-nav { display: flex !important; align-items: center; gap: 8px; }
  .primary-nav .menu { flex-direction: row; }
  .primary-nav .menu a { padding: 8px 12px; }
  .header-rfq { margin: 0 0 0 8px; }
}

/* ---------------- Hero ---------------- */
.gt-hero {
  background:
    linear-gradient(135deg, rgba(22,58,90,0.92), rgba(31,78,121,0.85)),
    repeating-linear-gradient(45deg, #1f4e79 0 12px, #163a5a 12px 24px);
  color: #fff;
  padding: 56px 0;
  position: relative;
}
.hero-eyebrow {
  text-transform: uppercase; letter-spacing: 2px;
  font-size: 0.8rem; color: var(--gt-accent); margin: 0 0 8px;
}
.hero-title { font-size: 1.9rem; margin: 0 0 12px; line-height: 1.25; }
.hero-sub { max-width: 720px; opacity: 0.92; margin: 0 0 20px; }
.hero-cta { display: flex; gap: 12px; flex-wrap: wrap; }
.hero-note { margin-top: 16px; font-size: 0.8rem; opacity: 0.75; }

@media (min-width: 900px) {
  .gt-hero { padding: 96px 0; }
  .hero-title { font-size: 2.6rem; }
}

/* ---------------- Buttons ---------------- */
.btn {
  display: inline-block; padding: 12px 22px;
  border-radius: var(--gt-radius); font-weight: 600;
  border: 2px solid transparent; cursor: pointer;
  transition: all .15s ease;
}
.btn-primary { background: var(--gt-accent); color: #fff; }
.btn-primary:hover { background: var(--gt-accent-dark); color: #fff; }
.btn-ghost { background: transparent; color: #fff; border-color: #fff; }
.btn-ghost:hover { background: #fff; color: var(--gt-steel-dark); }
.btn-lg { padding: 14px 28px; }

/* ---------------- Sections ---------------- */
.section { padding: 48px 0; }
.section-title {
  font-size: 1.5rem; margin: 0 0 8px; color: var(--gt-steel-dark);
  border-left: 4px solid var(--gt-accent); padding-left: 12px;
}
.section-note { color: var(--gt-text-soft); font-size: 0.9rem; }
.section-cta { margin-top: 20px; }

/* Selling points */
.points-grid {
  display: grid; gap: 16px; margin-top: 24px;
  grid-template-columns: 1fr;
}
@media (min-width: 640px) { .points-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 900px) { .points-grid { grid-template-columns: repeat(4, 1fr); } }
.point-card {
  background: var(--gt-surface); padding: 20px;
  border-radius: var(--gt-radius); border-top: 3px solid var(--gt-steel);
  box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}
.point-card h3 { margin: 0 0 8px; font-size: 1.05rem; color: var(--gt-steel-dark); }
.point-card p { margin: 0; font-size: 0.92rem; color: var(--gt-text-soft); }

/* Spec table */
.spec-table-wrap { overflow-x: auto; margin-top: 20px; }
.spec-table {
  width: 100%; border-collapse: collapse; background: var(--gt-surface);
  border-radius: var(--gt-radius); overflow: hidden;
}
.spec-table th, .spec-table td {
  padding: 10px 14px; border: 1px solid var(--gt-line); text-align: left;
  font-size: 0.95rem;
}
.spec-table thead th { background: var(--gt-steel); color: #fff; }
.spec-table-detail th { width: 38%; background: var(--gt-steel-soft); }

/* Applications */
.apps-grid {
  display: grid; gap: 12px; margin-top: 20px;
  grid-template-columns: repeat(2, 1fr);
}
@media (min-width: 900px) { .apps-grid { grid-template-columns: repeat(3, 1fr); } }
.app-card {
  background: var(--gt-surface); padding: 22px 16px; text-align: center;
  border-radius: var(--gt-radius); border: 1px solid var(--gt-line);
  color: var(--gt-steel-dark); font-weight: 600;
  background-image: repeating-linear-gradient(45deg, rgba(31,78,121,0.04) 0 6px, transparent 6px 12px);
}
.app-card:hover { border-color: var(--gt-accent); color: var(--gt-accent-dark); }

/* RFQ section */
.section-rfq { background: var(--gt-steel-dark); color: #fff; }
.rfq-inner { text-align: center; }
.rfq-inner .section-title { color: #fff; border-color: var(--gt-accent); }

/* ---------------- Layout with sidebar ---------------- */
.layout-with-sidebar {
  display: grid; grid-template-columns: 1fr; gap: 24px;
}
@media (min-width: 900px) {
  .layout-with-sidebar { grid-template-columns: 1fr 320px; }
}
.sidebar-col .widget {
  background: var(--gt-surface); padding: 16px;
  border-radius: var(--gt-radius); border: 1px solid var(--gt-line);
  margin-bottom: 16px;
}
.widget-title { font-size: 1rem; margin: 0 0 10px; color: var(--gt-steel-dark); }

/* ---------------- Product cards ---------------- */
.product-grid {
  display: grid; gap: 16px; margin-top: 20px;
  grid-template-columns: 1fr;
}
@media (min-width: 640px) { .product-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 900px) { .product-grid { grid-template-columns: repeat(3, 1fr); } }
.product-card {
  background: var(--gt-surface); border-radius: var(--gt-radius);
  overflow: hidden; border: 1px solid var(--gt-line);
  display: flex; flex-direction: column;
}
.product-card-media { aspect-ratio: 4/3; background: var(--gt-steel-soft); display: block; }
.product-card-media img { width: 100%; height: 100%; object-fit: cover; }
.media-placeholder {
  display: flex; align-items: center; justify-content: center;
  background: var(--gt-steel-soft); color: var(--gt-text-soft);
  padding: 24px; font-size: 0.9rem; min-height: 120px;
}
.product-card-body { padding: 14px; }
.product-card-title { margin: 0 0 6px; font-size: 1.05rem; }
.product-card-excerpt { font-size: 0.9rem; color: var(--gt-text-soft); }
.product-card-link { font-weight: 600; font-size: 0.9rem; }
.series-title {
  margin-top: 32px; color: var(--gt-steel-dark);
  border-left: 4px solid var(--gt-accent); padding-left: 10px;
}

/* ---------------- FAQ ---------------- */
.gtg-faq-item {
  background: var(--gt-surface); border: 1px solid var(--gt-line);
  border-radius: var(--gt-radius); margin-bottom: 10px; padding: 12px 16px;
}
.gtg-faq-q { cursor: pointer; font-weight: 600; color: var(--gt-steel-dark); }
.gtg-faq-a { margin-top: 8px; color: var(--gt-text-soft); }

/* ---------------- RFQ form ---------------- */
.rfq-form { display: grid; gap: 12px; margin-top: 16px; }
.rfq-form label { display: grid; gap: 4px; font-size: 0.92rem; }
.rfq-form input, .rfq-form textarea {
  padding: 10px; border: 1px solid var(--gt-line); border-radius: var(--gt-radius);
  font: inherit;
}
.rfq-hint { font-size: 0.9rem; color: var(--gt-text-soft); background: #fff8ec; padding: 10px; border-left: 3px solid var(--gt-accent); }

/* ---------------- Footer ---------------- */
.site-footer {
  background: var(--gt-charcoal); color: #cfd6de; margin-top: 48px;
}
.footer-grid {
  display: grid; gap: 24px; padding: 40px 16px 16px;
  grid-template-columns: 1fr;
}
@media (min-width: 900px) { .footer-grid { grid-template-columns: 2fr 1fr 1fr; } }
.footer-title { color: #fff; font-size: 1rem; margin: 0 0 10px; }
.footer-menu { list-style: none; margin: 0; padding: 0; }
.footer-menu a { color: #cfd6de; display: block; padding: 3px 0; }
.footer-contact { list-style: none; margin: 0; padding: 0; }
.footer-contact li { padding: 3px 0; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.1); padding: 14px 0; font-size: 0.85rem; }

/* ---------------- Misc ---------------- */
.entry-card {
  background: var(--gt-surface); padding: 20px;
  border-radius: var(--gt-radius); margin-bottom: 16px;
  border: 1px solid var(--gt-line);
}
.entry-title { margin: 0 0 6px; }
.entry-meta { font-size: 0.85rem; color: var(--gt-text-soft); margin-bottom: 8px; }
.error-code { font-size: 5rem; color: var(--gt-steel); margin: 0; line-height: 1; }
.page-header { margin-bottom: 20px; }
.page-title { color: var(--gt-steel-dark); margin: 0 0 8px; }
.product-detail { background: var(--gt-surface); padding: 24px; border-radius: var(--gt-radius); }
.product-cta { margin-top: 20px; }