/* ===========================
   九土科技 Global Stylesheet
   =========================== */
@import url('https://fonts.googleapis.com/css2?family=Noto+Serif+SC:wght@400;700&family=Inter:wght@300;400;500;600;700&display=swap');

:root {
  --bg-dark: #0a0f1e;
  --bg-card: #0f1628;
  --bg-card2: #131d35;
  --accent: #4da6ff;
  --accent2: #a78bfa;
  --gold: #c9a84c;
  --text-primary: #e8eaf6;
  --text-secondary: #94a3b8;
  --border: rgba(77, 166, 255, 0.15);
  --glow: rgba(77, 166, 255, 0.25);
  --blur: blur(14px);
  --radius: 12px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', 'Noto Serif SC', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg-dark);
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.7;
}

/* === NAV === */
nav {
  position: sticky;
  top: 0;
  z-index: 999;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 5%;
  height: 68px;
  background: rgba(10, 15, 30, 0.85);
  backdrop-filter: var(--blur);
  border-bottom: 1px solid var(--border);
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.nav-logo-text {
  font-family: 'Noto Serif SC', serif;
  font-weight: 700;
  font-size: 1.2rem;
  background: linear-gradient(135deg, #fff 40%, var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 2rem;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  transition: color 0.2s;
  position: relative;
  padding-bottom: 4px;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width 0.3s ease;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--text-primary);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

/* Hamburger (mobile) */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
}
.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  transition: all 0.3s;
}

/* === HERO === */
.hero {
  position: relative;
  height: 580px;
  display: flex;
  align-items: center;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background-image: url('/hero.png');
  background-size: cover;
  background-position: center;
  filter: brightness(0.45);
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, rgba(10,15,30,0.85) 40%, transparent);
}

.hero-content {
  position: relative;
  z-index: 1;
  padding: 0 8%;
  max-width: 680px;
}

.hero-eyebrow {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1rem;
}

.hero h1 {
  font-family: 'Noto Serif SC', serif;
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 700;
  line-height: 1.25;
  color: #fff;
  margin-bottom: 1.25rem;
}

.hero p {
  font-size: 1.05rem;
  color: rgba(255,255,255,0.75);
  max-width: 520px;
  margin-bottom: 2rem;
}

.btn-primary {
  display: inline-block;
  padding: 0.75rem 2rem;
  background: var(--accent);
  color: #fff;
  font-weight: 600;
  text-decoration: none;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s;
}

.btn-primary:hover {
  background: #6ab9ff;
  transform: translateY(-1px);
}

.btn-outline {
  display: inline-block;
  padding: 0.75rem 2rem;
  border: 1px solid var(--accent);
  color: var(--accent);
  font-weight: 600;
  text-decoration: none;
  border-radius: 8px;
  margin-left: 1rem;
  transition: background 0.2s;
}

.btn-outline:hover {
  background: rgba(77,166,255,0.1);
}

/* === SECTION COMMON === */
section {
  padding: 5rem 5%;
}

.section-label {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.6rem;
}

.section-title {
  font-family: 'Noto Serif SC', serif;
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  font-weight: 700;
  margin-bottom: 1rem;
  color: #fff;
}

.section-subtitle {
  font-size: 1rem;
  color: var(--text-secondary);
  max-width: 640px;
  margin-bottom: 3rem;
}

/* === SERVICES / PRODUCTS === */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  transition: all 0.3s;
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  opacity: 0;
  transition: opacity 0.3s;
}

.card:hover {
  border-color: rgba(77,166,255,0.35);
  transform: translateY(-4px);
  box-shadow: 0 16px 40px rgba(0,0,0,0.4);
}

.card:hover::before { opacity: 1; }

.card-icon {
  font-size: 2.2rem;
  margin-bottom: 1rem;
}

.card-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 0.75rem;
}

.card-body {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.card-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 1.25rem;
  font-size: 0.88rem;
  color: var(--accent);
  text-decoration: none;
  font-weight: 600;
  transition: gap 0.2s;
}

.card-link:hover { gap: 10px; }

/* === SUB CARDS === */
.sub-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
  margin-top: 3rem;
}

.sub-card {
  background: var(--bg-card2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: all 0.3s;
  text-decoration: none;
  color: inherit;
  display: block;
}

.sub-card:hover {
  border-color: var(--accent);
  box-shadow: 0 0 20px var(--glow);
}

.sub-card h3 {
  font-size: 1rem;
  font-weight: 600;
  color: #fff;
  margin-bottom: 0.5rem;
}

.sub-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* === STATS === */
.stats-section {
  background: var(--bg-card);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 4rem 5%;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 2rem;
  text-align: center;
}

.stat-number {
  font-size: 2.8rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  display: block;
}

.stat-label {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-top: 0.4rem;
}

/* === ABOUT INTRO === */
.about-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.about-text p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
  line-height: 1.9;
}

.highlight-box {
  background: var(--bg-card2);
  border-left: 4px solid var(--accent);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 1.5rem 2rem;
  margin: 1.5rem 0;
}

.highlight-box p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin: 0;
  line-height: 1.8;
}

.services-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 1.5rem;
}

.services-list li {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  padding: 1rem 1.25rem;
  background: var(--bg-card2);
  border: 1px solid var(--border);
  border-radius: 10px;
  font-size: 0.95rem;
  color: var(--text-secondary);
}

.services-list li span.bullet {
  color: var(--accent);
  font-size: 1.2rem;
  flex-shrink: 0;
  margin-top: 1px;
}

/* === TIMELINE === */
.timeline {
  position: relative;
  padding-left: 2rem;
  border-left: 2px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 2.5rem;
}

.timeline-item {
  position: relative;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -2.45rem;
  top: 6px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 8px var(--glow);
}

.timeline-year {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 0.3rem;
  letter-spacing: 1px;
}

.timeline-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
}

/* === PRODUCT PAGE === */
.product-layout {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 2.5rem;
  align-items: start;
}

.product-sidebar {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  position: sticky;
  top: 90px;
}

.product-sidebar h3 {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  letter-spacing: 2px;
  text-transform: uppercase;
  margin-bottom: 1rem;
}

.product-sidebar ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.product-sidebar a {
  display: block;
  padding: 0.6rem 0.8rem;
  border-radius: 8px;
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 0.9rem;
  transition: all 0.2s;
}

.product-sidebar a:hover,
.product-sidebar a.active {
  background: rgba(77,166,255,0.1);
  color: var(--accent);
}

.product-content .tag {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  background: rgba(77,166,255,0.1);
  border: 1px solid var(--accent);
  border-radius: 20px;
  font-size: 0.78rem;
  color: var(--accent);
  margin-right: 0.5rem;
  margin-bottom: 0.5rem;
}

.spec-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 1.5rem;
}

.spec-table td {
  padding: 0.75rem 1rem;
  font-size: 0.9rem;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}

.spec-table td:first-child {
  color: var(--text-secondary);
  width: 30%;
  white-space: nowrap;
}

.spec-table td:last-child {
  color: var(--text-primary);
}

/* === CONTACT === */
.contact-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
}

.contact-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
}

.contact-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
  color: #fff;
  margin-bottom: 1.5rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border);
}

.contact-item {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
  margin-bottom: 1rem;
}

.contact-item .ci-icon {
  font-size: 1.3rem;
  flex-shrink: 0;
  margin-top: 2px;
}

.contact-item .ci-label {
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-bottom: 0.2rem;
}

.contact-item .ci-value {
  font-size: 0.95rem;
  color: var(--text-primary);
}

/* === DOCS  === */
.docs-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.doc-item {
  display: flex;
  align-items: center;
  gap: 1.2rem;
  padding: 1.25rem 1.5rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: all 0.2s;
}

.doc-item:hover {
  border-color: rgba(77,166,255,0.4);
  box-shadow: 0 4px 20px rgba(0,0,0,0.3);
}

.doc-icon {
  font-size: 2rem;
  flex-shrink: 0;
}

.doc-info h3 {
  font-size: 0.95rem;
  font-weight: 600;
  color: #fff;
  margin-bottom: 0.25rem;
}

.doc-info p {
  font-size: 0.82rem;
  color: var(--text-secondary);
}

/* === FOOTER === */
footer {
  background: #050a15;
  border-top: 1px solid var(--border);
  padding: 3rem 5% 1.5rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 2.5rem;
}

.footer-brand p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  max-width: 320px;
  margin-top: 0.75rem;
}

.footer-col h4 {
  font-size: 0.85rem;
  font-weight: 600;
  color: #fff;
  letter-spacing: 1px;
  margin-bottom: 1rem;
}

.footer-col ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.footer-col a {
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 0.88rem;
  transition: color 0.2s;
}

.footer-col a:hover { color: var(--accent); }

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  font-size: 0.8rem;
  color: #4a5568;
}

.footer-bottom a {
  color: #4a5568;
  text-decoration: none;
}

.footer-bottom a:hover { color: var(--accent); }

/* === RESPONSIVE === */
@media (max-width: 900px) {
  .about-layout,
  .contact-layout,
  .footer-grid { grid-template-columns: 1fr; }
  .product-layout { grid-template-columns: 1fr; }
  .product-sidebar { position: static; }
}

@media (max-width: 700px) {
  .nav-links {
    display: none;
    flex-direction: column;
    position: fixed;
    top: 68px; left: 0; right: 0;
    background: rgba(10,15,30,0.97);
    padding: 1.5rem 5%;
    gap: 1.2rem;
  }
  .nav-links.open { display: flex; }
  .hamburger { display: flex; }
  .hero { height: 480px; }
}

/* === ANIMATIONS === */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}

.animate-fadeup {
  animation: fadeUp 0.6s ease forwards;
}

.delay-1 { animation-delay: 0.1s; }
.delay-2 { animation-delay: 0.25s; }
.delay-3 { animation-delay: 0.4s; }