/* ═══════════════════════════════════════════════════
   聊盛金属 — main.css
   China-optimized: system fonts only, no external CDN
═══════════════════════════════════════════════════ */

/* ── Reset & Base ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --white:       #ffffff;
  --black:       #0d0d0d;
  --gray-50:     #f8f8f6;
  --gray-100:    #f0f0ed;
  --gray-200:    #ddddd8;
  --gray-300:    #c4c4be;
  --gray-400:    #9a9a93;
  --gray-600:    #5a5a54;
  --gray-700:    #3a3a35;
  --blue:        #1a56db;
  --blue-light:  #eff6ff;
  --blue-dark:   #1240aa;
  --red:         #dc2626;
  --green:       #16a34a;
  --border:      rgba(0,0,0,0.08);
  --text:        #111110;
  --text-sub:    #6b6b65;
  --radius-sm:   8px;
  --radius:      14px;
  --radius-lg:   24px;
  --shadow-sm:   0 1px 3px rgba(0,0,0,0.08);
  --shadow:      0 4px 16px rgba(0,0,0,0.08);
  --shadow-lg:   0 12px 40px rgba(0,0,0,0.12);
  --font-sans:   -apple-system, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-serif:  Georgia, "Times New Roman", "SimSun", serif;
  --nav-h:       64px;
}

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: var(--font-sans);
  color: var(--text);
  background: var(--white);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; }
ul, ol { list-style: none; }

/* ── Typography ── */
h1, h2, h3, h4, h5 {
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.02em;
  color: var(--black);
}
h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.6rem, 3.5vw, 2.5rem); }
h3 { font-size: clamp(1.2rem, 2.5vw, 1.6rem); }
h4 { font-size: 1.1rem; }

/* ═══════════════════════════════════════════════════
   NAVIGATION
═══════════════════════════════════════════════════ */
#site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 200;
  background: rgba(255,255,255,0.94);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  transition: box-shadow 0.3s;
}
#site-header.scrolled { box-shadow: 0 2px 20px rgba(0,0,0,0.07); }

.main-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--nav-h);
  padding: 0 6vw;
  max-width: 1400px;
  margin: 0 auto;
}

.nav-brand {
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 8px;
}
.brand-name {
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--black);
  letter-spacing: -0.03em;
}
.brand-name em { color: var(--blue); font-style: normal; }

.nav-menu {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}
.nav-link {
  padding: 0.5rem 0.85rem;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  color: var(--text-sub);
  font-weight: 500;
  transition: color 0.2s, background 0.2s;
  text-decoration: none;
}
.nav-link:hover, .nav-link.active {
  color: var(--text);
  background: var(--gray-100);
  text-decoration: none;
}
.nav-cta {
  margin-left: 0.5rem;
  padding: 0.5rem 1.25rem;
  background: var(--black);
  color: var(--white) !important;
  border-radius: 100px;
  font-size: 0.875rem;
  font-weight: 600;
  text-decoration: none;
  transition: background 0.2s, transform 0.15s;
}
.nav-cta:hover { background: var(--blue); transform: translateY(-1px); text-decoration: none; }

.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  width: 36px;
}
.nav-hamburger span {
  display: block;
  height: 1.5px;
  background: var(--black);
  transition: transform 0.2s, opacity 0.2s;
}
.nav-hamburger.open span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.nav-hamburger.open span:nth-child(2) { opacity: 0; }
.nav-hamburger.open span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

.mobile-menu {
  display: none;
  position: fixed;
  top: var(--nav-h);
  left: 0; right: 0;
  background: rgba(255,255,255,0.98);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  padding: 1.5rem 6vw 2rem;
  z-index: 199;
  flex-direction: column;
  gap: 0.25rem;
}
.mobile-menu.open { display: flex; }
.mobile-menu .nav-link { font-size: 1rem; padding: 0.75rem 1rem; border-radius: var(--radius-sm); }
.mobile-menu .nav-cta { margin: 0.5rem 0 0; text-align: center; padding: 0.85rem; border-radius: var(--radius); }

/* ═══════════════════════════════════════════════════
   LAYOUT & SECTION BASE
═══════════════════════════════════════════════════ */
.container { max-width: 1200px; margin: 0 auto; padding: 0 6vw; }
section { padding: 6rem 6vw; }

.section-eyebrow {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--blue);
  margin-bottom: 0.75rem;
}
.section-header { margin-bottom: 3rem; }
.section-header .section-title { margin-bottom: 1rem; }
.section-header .section-sub { color: var(--text-sub); max-width: 560px; }
.section-title em { font-style: normal; color: var(--blue); }

/* ── Breadcrumb ── */
.breadcrumb { padding: calc(var(--nav-h) + 1.5rem) 6vw 1.5rem; }
.breadcrumb ol { display: flex; flex-wrap: wrap; gap: 0.5rem; align-items: center; font-size: 0.8rem; }
.breadcrumb li { color: var(--text-sub); }
.breadcrumb li::after { content: '/'; margin-left: 0.5rem; color: var(--gray-300); }
.breadcrumb li:last-child::after { display: none; }
.breadcrumb li a { color: var(--text-sub); text-decoration: none; }
.breadcrumb li a:hover { color: var(--text); }
.breadcrumb .bc-current { color: var(--text); font-weight: 500; }

/* ═══════════════════════════════════════════════════
   HERO
═══════════════════════════════════════════════════ */
#hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: calc(var(--nav-h) + 4rem) 6vw 5rem;
  position: relative;
  overflow: hidden;
}
.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  background:
    radial-gradient(ellipse 70% 60% at 65% 40%, var(--blue-light) 0%, transparent 65%),
    radial-gradient(ellipse 40% 50% at 15% 75%, #f0f9ff 0%, transparent 55%);
}
.hero-grid {
  position: absolute;
  inset: 0;
  z-index: 0;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse 80% 80% at 50% 50%, black 20%, transparent 80%);
}
.hero-content {
  position: relative;
  z-index: 1;
  max-width: 760px;
}
.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--blue-light);
  color: var(--blue);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  padding: 0.4rem 1rem;
  border-radius: 100px;
  margin-bottom: 2rem;
  border: 1px solid rgba(26,86,219,0.15);
}
.hero-eyebrow::before {
  content: '';
  width: 6px; height: 6px;
  background: var(--blue);
  border-radius: 50%;
  animation: dot-pulse 2s infinite;
}
@keyframes dot-pulse {
  0%,100% { opacity: 1; transform: scale(1); }
  50%      { opacity: 0.4; transform: scale(0.7); }
}

.hero-title {
  font-size: clamp(2.4rem, 5.5vw, 4rem);
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin-bottom: 1.5rem;
  color: var(--black);
}
.hero-title .line2 { color: var(--blue); }

.hero-sub {
  font-size: 1rem;
  color: var(--text-sub);
  max-width: 580px;
  margin-bottom: 2.5rem;
  line-height: 1.85;
}
.hero-actions { display: flex; gap: 1rem; flex-wrap: wrap; margin-bottom: 3.5rem; }

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--black);
  color: var(--white);
  padding: 0.85rem 1.85rem;
  border-radius: 100px;
  font-weight: 600;
  font-size: 0.92rem;
  text-decoration: none;
  transition: background 0.2s, transform 0.15s;
  border: none;
  cursor: pointer;
  font-family: var(--font-sans);
}
.btn-primary:hover { background: var(--blue); transform: translateY(-2px); text-decoration: none; color: var(--white); }

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: transparent;
  color: var(--black);
  padding: 0.85rem 1.85rem;
  border-radius: 100px;
  font-weight: 600;
  font-size: 0.92rem;
  text-decoration: none;
  border: 1.5px solid var(--gray-200);
  transition: border-color 0.2s, transform 0.15s, background 0.2s;
  cursor: pointer;
  font-family: var(--font-sans);
}
.btn-secondary:hover { border-color: var(--black); background: var(--gray-50); transform: translateY(-2px); text-decoration: none; }

.hero-stats { display: flex; gap: 2.5rem; flex-wrap: wrap; }
.stat-item { }
.stat-num {
  font-size: 2rem;
  font-weight: 800;
  color: var(--black);
  line-height: 1;
  letter-spacing: -0.04em;
}
.stat-label { font-size: 0.78rem; color: var(--text-sub); margin-top: 4px; }

/* ── Hero float card ── */
.hero-float-card {
  position: absolute;
  bottom: 3rem; right: 6vw;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem 1.75rem;
  box-shadow: var(--shadow-lg);
  max-width: 260px;
  z-index: 2;
}
.float-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: #dcfce7;
  color: var(--green);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  padding: 0.25rem 0.65rem;
  border-radius: 100px;
  margin-bottom: 0.75rem;
}
.float-badge::before { content: '●'; font-size: 0.5rem; }
.float-title { font-size: 0.9rem; font-weight: 700; margin-bottom: 0.4rem; }
.float-desc  { font-size: 0.8rem; color: var(--text-sub); line-height: 1.6; }

.hero-scroll-hint {
  position: absolute;
  bottom: 2.5rem; left: 6vw;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.75rem;
  color: var(--gray-400);
  letter-spacing: 0.05em;
  animation: scroll-hint 2.5s ease-in-out infinite;
}
@keyframes scroll-hint {
  0%,100% { transform: translateY(0); opacity: 0.6; }
  50%      { transform: translateY(6px); opacity: 1; }
}
.scroll-arrow { font-size: 1rem; }

/* ═══════════════════════════════════════════════════
   TRUST BAND
═══════════════════════════════════════════════════ */
.trust-band {
  background: var(--gray-50);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 1.25rem 0;
  overflow: hidden;
  position: relative;
}
.trust-scroll {
  display: flex;
  gap: 2.5rem;
  white-space: nowrap;
  animation: trust-scroll 30s linear infinite;
}
@keyframes trust-scroll {
  from { transform: translateX(0); }
  to   { transform: translateX(-50%); }
}
.trust-item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.82rem;
  color: var(--text-sub);
  font-weight: 500;
  padding: 0.35rem 1.25rem;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 100px;
  flex-shrink: 0;
}
.trust-dot { width: 5px; height: 5px; background: var(--blue); border-radius: 50%; }

/* ═══════════════════════════════════════════════════
   PRODUCTS SECTION (homepage)
═══════════════════════════════════════════════════ */
#products-section { background: var(--white); }

.product-tabs {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 2rem;
}
.product-tab {
  padding: 0.5rem 1.1rem;
  border-radius: 100px;
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  border: 1.5px solid var(--gray-200);
  background: transparent;
  color: var(--text-sub);
  transition: all 0.2s;
  font-family: var(--font-sans);
}
.product-tab:hover { border-color: var(--blue); color: var(--blue); }
.product-tab.active {
  background: var(--blue);
  color: var(--white);
  border-color: var(--blue);
}

.products-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
}
.product-card {
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: box-shadow 0.25s, transform 0.25s;
  background: var(--white);
  display: flex;
  flex-direction: column;
}
.product-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
}
.product-thumb {
  width: 100%;
  height: 180px;
  background: var(--gray-100);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  position: relative;
}
.product-thumb img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.4s; }
.product-card:hover .product-thumb img { transform: scale(1.04); }
.product-thumb-placeholder {
  color: var(--gray-300);
  font-size: 0.8rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}
.thumb-icon { font-size: 2.5rem; }

.product-body { padding: 1.5rem; flex: 1; display: flex; flex-direction: column; }
.product-category-badge {
  display: inline-flex;
  align-items: center;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--blue);
  background: var(--blue-light);
  padding: 0.2rem 0.6rem;
  border-radius: 100px;
  margin-bottom: 0.65rem;
}
.product-name { font-size: 1.1rem; font-weight: 700; margin-bottom: 0.4rem; }
.product-grade { font-size: 0.78rem; color: var(--text-sub); margin-bottom: 0.75rem; }
.product-tagline { font-size: 0.875rem; color: var(--text-sub); line-height: 1.6; margin-bottom: 1.25rem; flex: 1; }
.product-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--blue);
  text-decoration: none;
  border-top: 1px solid var(--border);
  padding-top: 1rem;
  margin-top: auto;
  transition: gap 0.2s;
}
.product-link:hover { gap: 8px; text-decoration: none; }
.product-link::after { content: '→'; }

/* Products catalog page grid */
.catalog-hero {
  padding: calc(var(--nav-h) + 3rem) 6vw 3rem;
  background: var(--gray-50);
  border-bottom: 1px solid var(--border);
}

.category-list { display: flex; flex-direction: column; gap: 3rem; }
.category-section { }
.category-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 2px solid var(--gray-100);
}
.category-icon { font-size: 1.75rem; }
.category-title { font-size: 1.4rem; font-weight: 700; }
.category-desc { font-size: 0.875rem; color: var(--text-sub); margin-top: 0.25rem; }
.category-link {
  margin-left: auto;
  font-size: 0.82rem;
  color: var(--blue);
  text-decoration: none;
  white-space: nowrap;
  font-weight: 500;
}
.category-link:hover { text-decoration: underline; }

/* ═══════════════════════════════════════════════════
   PRODUCT DETAIL
═══════════════════════════════════════════════════ */
.product-detail-layout {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 4rem;
  padding: 3rem 6vw 5rem;
}
.product-gallery { position: sticky; top: calc(var(--nav-h) + 2rem); align-self: start; }
.gallery-main {
  aspect-ratio: 4/3;
  background: var(--gray-100);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
}
.gallery-main img { width: 100%; height: 100%; object-fit: cover; }
.gallery-thumbs { display: flex; gap: 0.75rem; }
.gallery-thumb {
  width: 72px; height: 54px;
  border-radius: var(--radius-sm);
  overflow: hidden;
  cursor: pointer;
  border: 2px solid transparent;
  transition: border-color 0.2s;
  background: var(--gray-100);
}
.gallery-thumb.active { border-color: var(--blue); }
.gallery-thumb img { width: 100%; height: 100%; object-fit: cover; }

.product-info .product-category-badge { margin-bottom: 0.75rem; }
.product-info h1 { font-size: clamp(1.6rem, 3vw, 2.4rem); margin-bottom: 0.5rem; }
.product-info .product-grade { font-size: 0.9rem; color: var(--text-sub); margin-bottom: 1rem; }
.product-info .product-desc { color: var(--text-sub); line-height: 1.8; margin-bottom: 2rem; }

.spec-table { width: 100%; border-collapse: collapse; margin-bottom: 2rem; }
.spec-table th, .spec-table td {
  padding: 0.75rem 1rem;
  text-align: left;
  font-size: 0.875rem;
  border-bottom: 1px solid var(--gray-100);
}
.spec-table th { background: var(--gray-50); font-weight: 600; color: var(--text-sub); width: 40%; }
.spec-table td { font-weight: 500; }

.applications-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 2rem;
}
.app-tag {
  font-size: 0.78rem;
  padding: 0.3rem 0.85rem;
  background: var(--gray-100);
  border-radius: 100px;
  color: var(--text-sub);
  font-weight: 500;
}

.inquiry-cta {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  padding: 1.75rem;
  background: var(--gray-50);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
}
.inquiry-cta h4 { font-size: 1rem; margin-bottom: 0.25rem; }
.inquiry-cta p  { font-size: 0.85rem; color: var(--text-sub); }
.inquiry-cta .btn-primary { width: 100%; justify-content: center; }
.inquiry-tel { text-align: center; font-size: 0.82rem; color: var(--text-sub); }
.inquiry-tel a { color: var(--blue); font-weight: 600; }

/* ═══════════════════════════════════════════════════
   SOLUTIONS
═══════════════════════════════════════════════════ */
#solutions-section { background: var(--gray-50); }
.solutions-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}
.solution-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  text-decoration: none;
  color: var(--text);
  transition: box-shadow 0.2s, transform 0.2s;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  position: relative;
  overflow: hidden;
}
.solution-card::after {
  content: '→';
  position: absolute;
  bottom: 1.5rem; right: 1.75rem;
  font-size: 1.1rem;
  color: var(--blue);
  opacity: 0;
  transform: translateX(-6px);
  transition: opacity 0.2s, transform 0.2s;
}
.solution-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-3px);
  text-decoration: none;
  color: var(--text);
}
.solution-card:hover::after { opacity: 1; transform: translateX(0); }
.solution-icon { font-size: 2.2rem; }
.solution-industry { font-size: 0.7rem; font-weight: 700; letter-spacing: 0.1em; text-transform: uppercase; color: var(--blue); }
.solution-title { font-size: 1.1rem; font-weight: 700; line-height: 1.35; }
.solution-tagline { font-size: 0.875rem; color: var(--text-sub); line-height: 1.6; }

/* ═══════════════════════════════════════════════════
   CASES
═══════════════════════════════════════════════════ */
#cases-section { background: var(--black); color: var(--white); }
#cases-section .section-eyebrow { color: rgba(255,255,255,0.4); }
#cases-section .section-title   { color: var(--white); }
#cases-section .section-sub     { color: rgba(255,255,255,0.5); }

.cases-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
  margin-top: 0;
}
.case-card {
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius-lg);
  padding: 2rem;
  transition: background 0.2s;
}
.case-card:hover { background: rgba(255,255,255,0.07); }
.case-industry {
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.35);
  margin-bottom: 0.65rem;
}
.case-title {
  font-size: 1.1rem;
  color: var(--white);
  margin-bottom: 0.75rem;
  line-height: 1.4;
}
.case-summary {
  font-size: 0.85rem;
  color: rgba(255,255,255,0.5);
  line-height: 1.75;
  margin-bottom: 1.5rem;
}
.case-results { display: flex; gap: 2rem; }
.result-num {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--white);
  line-height: 1;
  letter-spacing: -0.04em;
}
.result-label { font-size: 0.72rem; color: rgba(255,255,255,0.35); margin-top: 4px; }
.case-more-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 0.82rem;
  color: rgba(255,255,255,0.4);
  text-decoration: none;
  margin-top: 1.25rem;
  transition: color 0.2s;
}
.case-more-link:hover { color: rgba(255,255,255,0.8); text-decoration: none; }
.case-more-link::after { content: '→'; }

.cases-partners {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 3rem;
  padding-top: 2.5rem;
  border-top: 1px solid rgba(255,255,255,0.06);
}
.partners-label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: rgba(255,255,255,0.2);
  margin-right: 0.5rem;
}
.partner-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 100px;
  padding: 0.35rem 0.9rem;
  font-size: 0.8rem;
  color: rgba(255,255,255,0.45);
}
.partner-dot { width: 4px; height: 4px; background: var(--blue); border-radius: 50%; }

/* ═══════════════════════════════════════════════════
   ADVANTAGES (stats)
═══════════════════════════════════════════════════ */
#advantages-section { background: var(--white); }
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}
.advantage-card {
  background: var(--gray-50);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem 1.5rem;
  text-align: center;
}
.adv-num {
  font-size: 2.4rem;
  font-weight: 900;
  color: var(--black);
  line-height: 1;
  letter-spacing: -0.05em;
  margin-bottom: 0.4rem;
}
.adv-num span { color: var(--blue); }
.adv-label { font-size: 0.85rem; color: var(--text-sub); }

/* ═══════════════════════════════════════════════════
   KNOWLEDGE / ARTICLES
═══════════════════════════════════════════════════ */
#knowledge-section { background: var(--gray-50); }
.knowledge-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}
.article-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  text-decoration: none;
  color: var(--text);
  transition: box-shadow 0.2s, transform 0.2s;
  display: flex;
  flex-direction: column;
}
.article-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-3px); text-decoration: none; color: var(--text); }
.article-thumb {
  height: 160px;
  background: var(--gray-100);
  overflow: hidden;
  position: relative;
}
.article-thumb img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.4s; }
.article-card:hover .article-thumb img { transform: scale(1.04); }
.article-thumb-placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
  font-size: 2rem;
  color: var(--gray-300);
}
.article-body { padding: 1.5rem; flex: 1; display: flex; flex-direction: column; }
.article-cat {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--blue);
  margin-bottom: 0.6rem;
}
.article-title { font-size: 1rem; font-weight: 700; line-height: 1.4; margin-bottom: 0.75rem; }
.article-summary { font-size: 0.85rem; color: var(--text-sub); line-height: 1.65; flex: 1; }
.article-meta { font-size: 0.75rem; color: var(--gray-400); margin-top: 1rem; }

/* ═══════════════════════════════════════════════════
   FAQ
═══════════════════════════════════════════════════ */
#faq-section { background: var(--white); }
.faq-list { display: flex; flex-direction: column; gap: 0; max-width: 820px; }
.faq-item {
  border-bottom: 1px solid var(--gray-100);
}
.faq-item:first-child { border-top: 1px solid var(--gray-100); }
.faq-question {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.25rem 0;
  cursor: pointer;
  font-size: 0.95rem;
  font-weight: 600;
  gap: 1rem;
  list-style: none;
  user-select: none;
}
.faq-question::-webkit-details-marker { display: none; }
.faq-question .faq-icon {
  flex-shrink: 0;
  width: 24px; height: 24px;
  border: 1.5px solid var(--gray-200);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  color: var(--text-sub);
  transition: transform 0.2s, border-color 0.2s;
}
details[open] .faq-icon { transform: rotate(45deg); border-color: var(--blue); color: var(--blue); }
.faq-answer {
  padding-bottom: 1.25rem;
  font-size: 0.875rem;
  color: var(--text-sub);
  line-height: 1.8;
}

/* ═══════════════════════════════════════════════════
   CONTACT
═══════════════════════════════════════════════════ */
#contact-section { background: var(--gray-50); }
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: 4rem;
  align-items: start;
}
.contact-info-item {
  display: flex;
  gap: 1rem;
  margin-bottom: 1.5rem;
  align-items: flex-start;
}
.ci-icon {
  width: 44px; height: 44px;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  flex-shrink: 0;
  box-shadow: var(--shadow-sm);
}
.ci-label { font-size: 0.72rem; color: var(--text-sub); margin-bottom: 3px; letter-spacing: 0.02em; }
.ci-value { font-size: 0.92rem; font-weight: 600; color: var(--text); }
.ci-value a { color: var(--text); text-decoration: none; }
.ci-value a:hover { color: var(--blue); }

/* ── Contact Form ── */
.contact-form-wrap {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}
.form-title { font-size: 1.2rem; margin-bottom: 0.35rem; }
.form-subtitle { font-size: 0.85rem; color: var(--text-sub); margin-bottom: 2rem; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.form-group { display: flex; flex-direction: column; gap: 0.35rem; margin-bottom: 1rem; }
.form-label { font-size: 0.78rem; font-weight: 600; color: var(--text-sub); letter-spacing: 0.02em; }
.form-required::after { content: ' *'; color: var(--red); }
.form-input, .form-select, .form-textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius-sm);
  font-family: var(--font-sans);
  font-size: 0.9rem;
  background: var(--white);
  color: var(--text);
  transition: border-color 0.2s, box-shadow 0.2s;
  outline: none;
  -webkit-appearance: none;
}
.form-input:focus, .form-select:focus, .form-textarea:focus {
  border-color: var(--blue);
  box-shadow: 0 0 0 3px rgba(26,86,219,0.08);
}
.form-textarea { min-height: 100px; resize: vertical; }
.form-input.error, .form-select.error, .form-textarea.error { border-color: var(--red); }
.form-error { font-size: 0.75rem; color: var(--red); }
.form-submit {
  width: 100%;
  background: var(--black);
  color: var(--white);
  border: none;
  padding: 0.95rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-sans);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s;
  margin-top: 0.5rem;
}
.form-submit:hover:not(:disabled) { background: var(--blue); }
.form-submit:disabled { opacity: 0.6; cursor: not-allowed; }
.form-success {
  display: none;
  text-align: center;
  padding: 2rem;
}
.form-success .success-icon { font-size: 2.5rem; margin-bottom: 1rem; }
.form-success h4 { margin-bottom: 0.5rem; }
.form-success p { font-size: 0.875rem; color: var(--text-sub); }

/* ═══════════════════════════════════════════════════
   ABOUT PAGE
═══════════════════════════════════════════════════ */
.about-intro {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 5rem;
  align-items: start;
  padding: 4rem 6vw;
}
.about-img-wrap {
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--gray-100);
  aspect-ratio: 4/3;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  color: var(--gray-400);
  position: sticky;
  top: calc(var(--nav-h) + 2rem);
}
.about-img-wrap img { width: 100%; height: 100%; object-fit: cover; }

.about-features-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
  padding: 0 6vw 4rem;
}
.feature-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  transition: box-shadow 0.2s;
}
.feature-card:hover { box-shadow: var(--shadow); }
.feature-icon { font-size: 1.75rem; margin-bottom: 0.85rem; }
.feature-title { font-size: 1rem; font-weight: 700; margin-bottom: 0.5rem; }
.feature-desc { font-size: 0.875rem; color: var(--text-sub); line-height: 1.7; }

.timeline-section { background: var(--gray-50); padding: 4rem 6vw; }
.timeline { position: relative; padding-left: 2rem; }
.timeline::before {
  content: '';
  position: absolute;
  left: 7px; top: 8px; bottom: 8px;
  width: 2px;
  background: var(--gray-200);
}
.timeline-item { position: relative; margin-bottom: 2rem; }
.timeline-item::before {
  content: '';
  position: absolute;
  left: -2rem;
  top: 6px;
  width: 10px; height: 10px;
  border-radius: 50%;
  background: var(--blue);
  border: 2px solid var(--white);
  box-shadow: 0 0 0 2px var(--blue);
}
.timeline-year { font-size: 0.78rem; font-weight: 700; color: var(--blue); margin-bottom: 0.25rem; }
.timeline-event { font-size: 0.9rem; font-weight: 500; }

/* ═══════════════════════════════════════════════════
   FOOTER
═══════════════════════════════════════════════════ */
#site-footer {
  background: var(--black);
  color: rgba(255,255,255,0.7);
  padding: 4rem 6vw 2.5rem;
}
.footer-inner {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1.2fr;
  gap: 3rem;
  padding-bottom: 3rem;
  border-bottom: 1px solid rgba(255,255,255,0.08);
  margin-bottom: 2.5rem;
}
.footer-logo {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--white);
  text-decoration: none;
  display: block;
  margin-bottom: 0.75rem;
  letter-spacing: -0.02em;
}
.footer-tagline { font-size: 0.85rem; color: rgba(255,255,255,0.4); line-height: 1.6; }
#site-footer h4 { font-size: 0.8rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.1em; color: rgba(255,255,255,0.3); margin-bottom: 1rem; }
.footer-links-group ul { display: flex; flex-direction: column; gap: 0.6rem; }
.footer-links-group a { font-size: 0.875rem; color: rgba(255,255,255,0.6); text-decoration: none; transition: color 0.2s; }
.footer-links-group a:hover { color: var(--white); }
.footer-contact p { font-size: 0.875rem; margin-bottom: 0.5rem; }
.footer-contact a { color: rgba(255,255,255,0.6); text-decoration: none; transition: color 0.2s; }
.footer-contact a:hover { color: var(--white); }
.footer-addr { font-size: 0.82rem; color: rgba(255,255,255,0.35); line-height: 1.6; margin-top: 0.75rem; }
.footer-bottom { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 1rem; }
.footer-bottom p { font-size: 0.8rem; color: rgba(255,255,255,0.25); }
.footer-bottom a { color: rgba(255,255,255,0.25); text-decoration: none; transition: color 0.2s; }
.footer-bottom a:hover { color: rgba(255,255,255,0.5); }

/* ── Mobile bottom sticky bar ── */
.mobile-bottom-bar {
  display: none;
  position: fixed;
  bottom: 0; left: 0; right: 0;
  background: var(--white);
  border-top: 1px solid var(--border);
  padding: 0.75rem 1rem;
  z-index: 150;
  box-shadow: 0 -4px 20px rgba(0,0,0,0.08);
  gap: 0.75rem;
}
.mobile-bottom-bar .mbb-call {
  flex: 1;
  background: var(--black);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 0.7rem;
  border-radius: var(--radius-sm);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 600;
}
.mobile-bottom-bar .mbb-quote {
  flex: 1;
  background: var(--blue);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 0.7rem;
  border-radius: var(--radius-sm);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 600;
}

/* ═══════════════════════════════════════════════════
   PAGINATION
═══════════════════════════════════════════════════ */
.pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 0.5rem;
  padding: 3rem 0 1rem;
  flex-wrap: wrap;
}
.page-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px; height: 36px;
  border-radius: var(--radius-sm);
  border: 1.5px solid var(--gray-200);
  font-size: 0.85rem;
  color: var(--text-sub);
  text-decoration: none;
  transition: all 0.2s;
}
.page-link:hover { border-color: var(--blue); color: var(--blue); text-decoration: none; }
.page-link.active { background: var(--blue); border-color: var(--blue); color: var(--white); }
.page-link.disabled { opacity: 0.4; pointer-events: none; }

/* ═══════════════════════════════════════════════════
   SCROLL ANIMATIONS
═══════════════════════════════════════════════════ */
.fade-up {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.65s ease, transform 0.65s ease;
}
.fade-up.visible { opacity: 1; transform: none; }
.d1 { transition-delay: 0.1s; }
.d2 { transition-delay: 0.2s; }
.d3 { transition-delay: 0.3s; }
.d4 { transition-delay: 0.4s; }

/* ═══════════════════════════════════════════════════
   BACK TO TOP
═══════════════════════════════════════════════════ */
.back-to-top {
  position: fixed;
  bottom: 2rem; right: 1.5rem;
  width: 44px; height: 44px;
  background: var(--black);
  color: var(--white);
  border: none;
  border-radius: 50%;
  font-size: 1.1rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.3s, transform 0.3s, background 0.2s;
  pointer-events: none;
}
.back-to-top.visible { opacity: 1; transform: none; pointer-events: auto; }
.back-to-top:hover { background: var(--blue); }

/* ═══════════════════════════════════════════════════
   RESPONSIVE
═══════════════════════════════════════════════════ */
@media (max-width: 1024px) {
  .advantages-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-inner { grid-template-columns: 1fr 1fr; gap: 2rem; }
  .product-detail-layout { grid-template-columns: 1fr; gap: 2rem; }
  .product-gallery { position: static; }
}

@media (max-width: 768px) {
  :root { --nav-h: 60px; }
  section { padding: 4rem 5vw; }

  .nav-menu { display: none; }
  .nav-hamburger { display: flex; }

  .hero-float-card { display: none; }
  .hero-scroll-hint { display: none; }
  .hero-stats { gap: 1.5rem; }

  .products-grid { grid-template-columns: 1fr 1fr; }
  .solutions-grid { grid-template-columns: 1fr; }
  .cases-grid { grid-template-columns: 1fr; }
  .knowledge-grid { grid-template-columns: 1fr; }
  .advantages-grid { grid-template-columns: 1fr 1fr; }
  .contact-grid { grid-template-columns: 1fr; gap: 2.5rem; }
  .about-intro { grid-template-columns: 1fr; gap: 2rem; }
  .about-img-wrap { position: static; }
  .about-features-grid { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr; gap: 2rem; }
  .footer-bottom { flex-direction: column; text-align: center; }

  .mobile-bottom-bar { display: flex; }
  body { padding-bottom: 72px; }

  .back-to-top { bottom: 5.5rem; right: 1rem; }
}

@media (max-width: 480px) {
  .products-grid { grid-template-columns: 1fr; }
  .hero-actions { flex-direction: column; }
  .hero-actions .btn-primary,
  .hero-actions .btn-secondary { text-align: center; justify-content: center; }
}