/* ===== RESET & BASE ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --primary: #1a4d8f;
  --primary-dark: #0e3060;
  --primary-light: #2c6ab5;
  --accent: #e8821a;
  --accent-dark: #c96a0d;
  --green: #1e7a4f;
  --dark: #1a1a2e;
  --gray-bg: #f5f7fa;
  --gray-mid: #e8ecf2;
  --text: #2c3e50;
  --text-light: #6b7c93;
  --white: #ffffff;
  --radius: 12px;
  --shadow: 0 4px 24px rgba(0,0,0,0.10);
  --shadow-hover: 0 8px 40px rgba(0,0,0,0.18);
  --transition: 0.3s ease;
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
  color: var(--text);
  line-height: 1.7;
  background: var(--white);
  overflow-x: hidden;
}

a { text-decoration: none; color: inherit; }
ul { list-style: none; }
img { max-width: 100%; }

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-block;
  padding: 14px 32px;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: var(--transition);
  letter-spacing: 0.5px;
}
.btn-primary {
  background: var(--accent);
  color: var(--white);
}
.btn-primary:hover { background: var(--accent-dark); transform: translateY(-2px); box-shadow: 0 6px 20px rgba(232,130,26,0.35); }
.btn-outline {
  background: transparent;
  color: var(--white);
  border: 2px solid rgba(255,255,255,0.7);
}
.btn-outline:hover { background: rgba(255,255,255,0.15); border-color: var(--white); }
.btn-full { width: 100%; text-align: center; }

/* ===== SECTION COMMON ===== */
.section { padding: 96px 0; }
.section-gray { background: var(--gray-bg); }
.section-dark { background: var(--dark); color: var(--white); }

.section-header {
  text-align: center;
  margin-bottom: 60px;
}
.section-header.light h2,
.section-header.light p { color: var(--white); }

.section-tag {
  display: inline-block;
  background: rgba(26,77,143,0.1);
  color: var(--primary);
  padding: 6px 18px;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 14px;
  letter-spacing: 1px;
  text-transform: uppercase;
}
.section-tag.light {
  background: rgba(255,255,255,0.15);
  color: rgba(255,255,255,0.9);
}

.section-header h2 {
  font-size: clamp(1.8rem, 3vw, 2.6rem);
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 16px;
  line-height: 1.3;
}
.section-header p {
  color: var(--text-light);
  font-size: 1.05rem;
  max-width: 600px;
  margin: 0 auto;
}

/* ===== HEADER ===== */
#header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  padding: 0;
  background: transparent;
  transition: background 0.3s, box-shadow 0.3s;
}
#header.scrolled {
  background: var(--white);
  box-shadow: 0 2px 20px rgba(0,0,0,0.12);
}
#header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 14px;
}
.logo-icon {
  width: 48px; height: 48px;
  background: var(--accent);
  color: var(--white);
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.1rem;
  font-weight: 800;
  letter-spacing: -1px;
  flex-shrink: 0;
}
.logo-icon.small { width: 40px; height: 40px; font-size: 0.95rem; }
.logo-text { display: flex; flex-direction: column; }
.logo-cn {
  font-size: 1rem;
  font-weight: 700;
  color: var(--white);
  line-height: 1.2;
  transition: color 0.3s;
}
.logo-en {
  font-size: 0.65rem;
  color: rgba(255,255,255,0.7);
  font-weight: 400;
  letter-spacing: 0.5px;
  transition: color 0.3s;
}
#header.scrolled .logo-cn { color: var(--dark); }
#header.scrolled .logo-en { color: var(--text-light); }

#nav {
  display: flex;
  gap: 4px;
}
#nav a {
  padding: 8px 16px;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 500;
  color: rgba(255,255,255,0.9);
  transition: var(--transition);
}
#nav a:hover { background: rgba(255,255,255,0.15); color: var(--white); }
#header.scrolled #nav a { color: var(--text); }
#header.scrolled #nav a:hover { background: var(--gray-bg); color: var(--primary); }

.nav-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--white);
  cursor: pointer;
  padding: 8px;
}
#header.scrolled .nav-toggle { color: var(--dark); }

/* ===== HERO ===== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 120px 24px 0;
  overflow: hidden;
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 50%, #2c6ab5 100%);
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.hero-bg-img {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  opacity: 0.15;
  mix-blend-mode: luminosity;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 800px;
}

.hero-badge {
  display: inline-block;
  background: rgba(232,130,26,0.25);
  border: 1px solid rgba(232,130,26,0.5);
  color: #ffc87a;
  padding: 8px 20px;
  border-radius: 20px;
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 28px;
  letter-spacing: 1px;
}

.hero-tags {
  display: flex;
  gap: 10px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 20px;
}
.hero-tags span {
  background: rgba(255,255,255,0.12);
  border: 1px solid rgba(255,255,255,0.25);
  color: rgba(255,255,255,0.9);
  padding: 5px 14px;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 1px;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3.4rem);
  font-weight: 800;
  color: var(--white);
  line-height: 1.25;
  margin-bottom: 20px;
  letter-spacing: -0.5px;
}

.hero p {
  font-size: clamp(1rem, 2vw, 1.2rem);
  color: rgba(255,255,255,0.82);
  margin-bottom: 20px;
  line-height: 1.8;
}

.hero-motto {
  font-size: 1.15rem;
  color: rgba(255,255,255,0.65);
  letter-spacing: 3px;
  margin-bottom: 36px;
  font-weight: 300;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.hero-stats {
  position: relative;
  z-index: 2;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  background: rgba(255,255,255,0.08);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255,255,255,0.15);
  border-radius: 20px;
  padding: 28px 40px;
  margin-top: 60px;
  margin-bottom: 0;
  width: 100%;
  max-width: 700px;
}
.stat-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 0 32px;
  flex: 1;
}
.stat-num {
  font-size: 2rem;
  font-weight: 800;
  color: var(--white);
  line-height: 1;
}
.stat-label {
  font-size: 0.82rem;
  color: rgba(255,255,255,0.65);
  margin-top: 6px;
}
.stat-divider {
  width: 1px;
  height: 40px;
  background: rgba(255,255,255,0.2);
}

/* ===== LOGO ===== */
.logo-img { height: 48px; width: auto; object-fit: contain; }
#header.scrolled .logo-img { filter: none; }
#header:not(.scrolled) .logo-img { filter: brightness(10); }

/* ===== ABOUT ===== */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: start;
}
.about-img-wrap {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
}
.about-img {
  width: 100%;
  border-radius: var(--radius);
  display: block;
  object-fit: cover;
}
.about-img-badge {
  position: absolute;
  bottom: 20px; right: 20px;
  background: var(--accent);
  color: var(--white);
  border-radius: 12px;
  padding: 12px 20px;
  text-align: center;
}
.badge-num { display: block; font-size: 1.8rem; font-weight: 800; line-height: 1; }
.badge-text { font-size: 0.78rem; opacity: 0.9; }
.about-content h3 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 20px;
}
.about-content p {
  color: var(--text-light);
  margin-bottom: 16px;
  line-height: 1.85;
}
.about-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 20px 0;
}
.about-tag {
  background: rgba(26,77,143,0.08);
  color: var(--primary);
  padding: 7px 14px;
  border-radius: 8px;
  font-size: 0.85rem;
  font-weight: 600;
}
.about-info { margin-top: 20px; display: flex; flex-direction: column; gap: 10px; }
.info-item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.9rem;
  color: var(--text);
}
.info-item span { font-size: 1.1rem; }
.info-item strong { font-weight: 600; }

/* ===== PRODUCTS ===== */
.prod-category { margin-bottom: 56px; }
.prod-cat-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 24px;
  padding-bottom: 16px;
  border-bottom: 2px solid var(--gray-mid);
}
.prod-cat-num {
  width: 44px; height: 44px;
  background: var(--primary);
  color: var(--white);
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.1rem;
  font-weight: 800;
  flex-shrink: 0;
}
.prod-cat-header h3 { font-size: 1.3rem; font-weight: 700; color: var(--dark); margin-bottom: 2px; }
.prod-cat-header p { font-size: 0.82rem; color: var(--text-light); }

.prod-cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}
.prod-cards.four-col { grid-template-columns: repeat(4, 1fr); }

.prod-card {
  background: var(--white);
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--gray-mid);
  transition: var(--transition);
}
.prod-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.prod-card.mini .prod-info { padding: 16px; }

.prod-img-wrap {
  width: 100%;
  overflow: hidden;
  background: var(--gray-bg);
}
.prod-img-wrap img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  display: block;
  transition: transform 0.4s ease;
}
.prod-card:hover .prod-img-wrap img { transform: scale(1.04); }
.prod-card.mini .prod-img-wrap img { height: 160px; }

.prod-info { padding: 20px; }
.prod-info h4 { font-size: 1rem; font-weight: 700; color: var(--dark); margin-bottom: 10px; }
.prod-info p { font-size: 0.87rem; color: var(--text-light); line-height: 1.75; margin-bottom: 12px; }
.prod-specs-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.prod-specs-row span {
  background: rgba(26,77,143,0.07);
  color: var(--primary);
  padding: 4px 10px;
  border-radius: 5px;
  font-size: 0.78rem;
  font-weight: 600;
}

/* ===== FLOW ===== */
.solution-flow { background: var(--white); }
.flow-steps {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  gap: 0;
  flex-wrap: wrap;
}
.flow-step {
  text-align: center;
  flex: 1;
  min-width: 160px;
  max-width: 200px;
  padding: 0 12px;
  position: relative;
}
.flow-num {
  width: 36px; height: 36px;
  background: var(--accent);
  color: var(--white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
  font-weight: 800;
  margin: 0 auto 16px;
}
.flow-icon { font-size: 2.4rem; margin-bottom: 12px; }
.flow-step h4 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 8px;
}
.flow-step p { font-size: 0.82rem; color: var(--text-light); line-height: 1.6; }
.flow-arrow {
  font-size: 1.8rem;
  color: var(--primary);
  opacity: 0.4;
  align-self: center;
  padding-bottom: 40px;
  flex-shrink: 0;
}

/* ===== CASES ===== */
.cases-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.case-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow);
  transition: var(--transition);
  border: 1px solid var(--gray-mid);
}
.case-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }
.case-card.featured { border-top: 4px solid var(--accent); }
.case-flag-row {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 12px;
  font-size: 0.85rem;
  color: var(--text-light);
}
.case-loc { font-weight: 600; }
.case-badge {
  margin-left: auto;
  background: var(--accent);
  color: var(--white);
  padding: 3px 10px;
  border-radius: 4px;
  font-size: 0.75rem;
  font-weight: 700;
}
.case-badge.green { background: var(--green); }
.case-card h3 { font-size: 1.05rem; font-weight: 700; color: var(--dark); margin-bottom: 10px; }
.case-card p { font-size: 0.87rem; color: var(--text-light); margin-bottom: 14px; line-height: 1.75; }
.case-specs {
  display: flex;
  gap: 10px;
  margin-bottom: 14px;
}
.case-specs div {
  display: flex; flex-direction: column; align-items: center;
  background: var(--gray-bg); border-radius: 8px; padding: 8px 12px; flex: 1;
}
.case-specs span { font-size: 0.7rem; color: var(--text-light); }
.case-specs strong { font-size: 0.83rem; font-weight: 700; color: var(--dark); margin-top: 2px; }
.case-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.case-tags span {
  background: rgba(26,77,143,0.08);
  color: var(--primary);
  padding: 4px 10px;
  border-radius: 5px;
  font-size: 0.78rem;
  font-weight: 600;
}

/* ===== ADVANTAGES ===== */
.adv-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.adv-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 32px 28px;
  border: 1px solid var(--gray-mid);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}
.adv-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 4px; height: 100%;
  background: var(--primary);
  transform: scaleY(0);
  transition: transform 0.3s;
  transform-origin: bottom;
}
.adv-card:hover::before { transform: scaleY(1); }
.adv-card:hover { box-shadow: var(--shadow); transform: translateY(-3px); }
.adv-num {
  font-size: 2.5rem;
  font-weight: 900;
  color: var(--gray-mid);
  line-height: 1;
  margin-bottom: 4px;
}
.adv-icon { font-size: 1.8rem; margin-bottom: 14px; }
.adv-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 12px;
}
.adv-card p { font-size: 0.88rem; color: var(--text-light); line-height: 1.8; }

/* ===== CONTACT ===== */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: 60px;
  align-items: start;
}
.contact-info { display: flex; flex-direction: column; gap: 24px; }
.contact-item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}
.contact-icon {
  font-size: 1.5rem;
  background: rgba(255,255,255,0.1);
  padding: 12px;
  border-radius: 10px;
  flex-shrink: 0;
}
.contact-item h4 { font-size: 0.85rem; color: rgba(255,255,255,0.55); margin-bottom: 4px; }
.contact-item p { color: var(--white); font-weight: 500; }
.contact-item p.sub { font-size: 0.78rem; color: rgba(255,255,255,0.55); font-weight: 400; margin-top: 3px; }
.contact-motto {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 16px;
  padding: 20px;
  background: rgba(255,255,255,0.07);
  border-radius: 12px;
  border: 1px solid rgba(255,255,255,0.12);
}
.contact-motto p { color: rgba(255,255,255,0.85); font-size: 1.1rem; letter-spacing: 2px; }
.contact-motto span { color: var(--accent); font-size: 1.4rem; }

.contact-form {
  background: var(--white);
  border-radius: var(--radius);
  padding: 36px;
}
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.form-group { margin-bottom: 18px; }
.form-group label { display: block; font-size: 0.88rem; font-weight: 600; color: var(--dark); margin-bottom: 8px; }
.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  border: 1.5px solid var(--gray-mid);
  border-radius: 8px;
  font-family: inherit;
  font-size: 0.95rem;
  color: var(--text);
  transition: border-color 0.2s;
  background: var(--white);
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(26,77,143,0.08);
}
.form-group textarea { resize: vertical; }
.form-note {
  text-align: center;
  font-size: 0.82rem;
  color: var(--text-light);
  margin-top: 12px;
}

/* ===== FOOTER ===== */
.footer { background: #0e1a2b; color: rgba(255,255,255,0.7); }
.footer-top {
  padding: 56px 0 40px;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 60px;
  align-items: start;
  border-bottom: 1px solid rgba(255,255,255,0.08);
}
.footer-brand { display: flex; flex-direction: column; gap: 8px; }
.footer-logo-img { height: 44px; width: auto; filter: brightness(10); opacity: 0.9; }
.footer-brand p { font-size: 0.85rem; color: rgba(255,255,255,0.55); }
.footer-motto-text { color: rgba(255,255,255,0.75) !important; font-style: italic; letter-spacing: 1px; }
.footer-nav {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}
.footer-col h5 {
  color: var(--white);
  font-size: 0.9rem;
  font-weight: 700;
  margin-bottom: 16px;
  letter-spacing: 0.5px;
}
.footer-col a,
.footer-col span {
  display: block;
  font-size: 0.85rem;
  color: rgba(255,255,255,0.55);
  margin-bottom: 10px;
  transition: color 0.2s;
}
.footer-col a:hover { color: var(--white); }
.footer-bottom {
  padding: 24px 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.82rem;
  color: rgba(255,255,255,0.4);
}
.footer-motto { color: rgba(255,255,255,0.55); letter-spacing: 1px; }

/* ===== BACK TO TOP ===== */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 48px; height: 48px;
  background: var(--accent);
  color: var(--white);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  box-shadow: 0 4px 16px rgba(232,130,26,0.4);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s, transform 0.3s;
  z-index: 999;
}
.back-to-top.visible { opacity: 1; pointer-events: auto; }
.back-to-top:hover { transform: translateY(-4px); }

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
  .products-grid { grid-template-columns: repeat(2, 1fr); }
  .cases-grid { grid-template-columns: repeat(2, 1fr); }
  .adv-grid { grid-template-columns: repeat(2, 1fr); }
  .about-grid { grid-template-columns: 1fr; gap: 40px; }
}

@media (max-width: 768px) {
  .prod-cards.four-col {
    grid-template-columns: repeat(4, 1fr);
    gap: 6px;
  }
  .prod-cards.four-col .prod-card.mini .prod-img-wrap img {
    height: 80px;
  }
  .prod-cards.four-col .prod-card.mini .prod-info {
    padding: 8px 6px;
  }
  .prod-cards.four-col .prod-card.mini .prod-info h4 {
    font-size: 0.72rem;
    margin-bottom: 0;
    line-height: 1.3;
    word-break: keep-all;
  }
  .prod-cards.four-col .prod-card.mini .prod-info p {
    display: none;
  }
  .section { padding: 64px 0; }

  #nav { display: none; flex-direction: column; position: absolute; top: 72px; left: 0; right: 0; background: var(--white); box-shadow: 0 8px 24px rgba(0,0,0,0.12); padding: 16px; gap: 0; }
  #nav.open { display: flex; }
  #nav a { color: var(--text) !important; padding: 12px 16px; border-radius: 8px; }
  #nav a:hover { background: var(--gray-bg); }
  .nav-toggle { display: block; }

  .hero { padding-top: 100px; }
  .hero-stats { flex-wrap: wrap; padding: 20px; }
  .stat-item { min-width: 120px; padding: 12px 16px; }
  .stat-divider { display: none; }

  .products-grid { grid-template-columns: 1fr; }
  .cases-grid { grid-template-columns: 1fr; }
  .adv-grid { grid-template-columns: 1fr; }
  .about-cards { grid-template-columns: 1fr; }

  .contact-grid { grid-template-columns: 1fr; gap: 32px; }
  .form-row { grid-template-columns: 1fr; }

  .footer-top { grid-template-columns: 1fr; gap: 32px; }
  .footer-nav { grid-template-columns: repeat(2, 1fr); }
  .footer-bottom { flex-direction: column; gap: 8px; text-align: center; }

  .flow-steps { flex-direction: column; align-items: center; gap: 16px; }
  .flow-arrow { transform: rotate(90deg); padding-bottom: 0; }
  .flow-step { max-width: 280px; }
}

@media (max-width: 480px) {
  .prod-cards.four-col .prod-card.mini .prod-img-wrap img { height: 60px; }
  .hero-buttons { flex-direction: column; align-items: center; }
  .footer-nav { grid-template-columns: 1fr; }
}