/* ============================================
   检一网络科技 — High-End Website
   ============================================ */

/* --- Design Tokens --- */
:root {
  /* Color — Deep charcoal with warm gold accent */
  --bg-primary: #0c0c0e;
  --bg-secondary: #131316;
  --bg-elevated: #1a1a1f;
  --bg-surface: #222228;

  --text-primary: #e8e4de;
  --text-secondary: #9a9590;
  --text-tertiary: #5c5854;
  --text-inverse: #0c0c0e;

  --accent: #c9a96e;
  --accent-light: #dfc494;
  --accent-dim: #8a7345;

  --border: rgba(255, 255, 255, 0.06);
  --border-hover: rgba(255, 255, 255, 0.12);

  /* Typography */
  --font-serif: 'Noto Serif SC', 'Songti SC', serif;
  --font-sans: 'Instrument Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;

  /* Spacing (4pt base) */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  --space-4xl: 96px;
  --space-5xl: 128px;

  /* Motion */
  --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-out-quart: cubic-bezier(0.25, 1, 0.5, 1);
  --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);

  /* Layout */
  --nav-height: 72px;
  --container-max: 1200px;
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  max-width: 100%;
  display: block;
}

/* --- Cursor Glow --- */
.cursor-glow {
  position: fixed;
  width: 600px;
  height: 600px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(201, 169, 110, 0.04) 0%, transparent 70%);
  pointer-events: none;
  z-index: 0;
  transform: translate(-50%, -50%);
  transition: opacity 0.3s ease;
  opacity: 0;
}

.cursor-glow.active {
  opacity: 1;
}

/* --- Container --- */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 clamp(20px, 5vw, 48px);
}

/* --- Navigation --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--nav-height);
  transition: background 0.4s ease, backdrop-filter 0.4s ease;
}

.nav.scrolled {
  background: rgba(12, 12, 14, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 clamp(20px, 5vw, 48px);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  z-index: 101;
}

.logo-mark {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: 0.05em;
}

.logo-img {
  width: 32px;
  height: 32px;
  object-fit: contain;
  flex-shrink: 0;
}

.logo-text {
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 0.2em;
  text-transform: uppercase;
}

.logo-cn {
  font-family: var(--font-serif);
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
  letter-spacing: 0.08em;
  line-height: 1;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
}

.nav-link {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color 0.3s ease;
  letter-spacing: 0.02em;
}

.nav-link:hover {
  color: var(--text-primary);
}

.nav-link--cta {
  color: var(--accent);
  padding: 8px 20px;
  border: 1px solid var(--accent-dim);
  border-radius: 2px;
  transition: all 0.3s ease;
}

.nav-link--cta:hover {
  color: var(--bg-primary);
  background: var(--accent);
  border-color: var(--accent);
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  width: 32px;
  height: 32px;
  position: relative;
  z-index: 101;
}

.nav-toggle span {
  display: block;
  width: 20px;
  height: 1.5px;
  background: var(--text-primary);
  position: absolute;
  left: 6px;
  transition: all 0.3s var(--ease-out-expo);
}

.nav-toggle span:first-child { top: 12px; }
.nav-toggle span:last-child { bottom: 12px; }

.nav-toggle.active span:first-child {
  top: 50%;
  transform: rotate(45deg);
}

.nav-toggle.active span:last-child {
  bottom: 50%;
  transform: rotate(-45deg);
}

/* Mobile menu */
.mobile-menu {
  position: fixed;
  inset: 0;
  background: var(--bg-primary);
  z-index: 99;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.4s ease, visibility 0.4s ease;
}

.mobile-menu.open {
  opacity: 1;
  visibility: visible;
}

.mobile-menu-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-2xl);
}

.mobile-link {
  font-family: var(--font-serif);
  font-size: clamp(1.5rem, 5vw, 2.5rem);
  font-weight: 600;
  color: var(--text-primary);
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s var(--ease-out-expo), transform 0.5s var(--ease-out-expo), color 0.3s ease;
}

.mobile-menu.open .mobile-link {
  opacity: 1;
  transform: translateY(0);
}

.mobile-menu.open .mobile-link:nth-child(1) { transition-delay: 0.1s; }
.mobile-menu.open .mobile-link:nth-child(2) { transition-delay: 0.15s; }
.mobile-menu.open .mobile-link:nth-child(3) { transition-delay: 0.2s; }
.mobile-menu.open .mobile-link:nth-child(4) { transition-delay: 0.25s; }

.mobile-link:hover {
  color: var(--accent);
}

/* --- Hero --- */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  position: relative;
  padding: var(--nav-height) 0 var(--space-3xl);
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.02) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.02) 1px, transparent 1px);
  background-size: 80px 80px;
  mask-image: radial-gradient(ellipse 60% 60% at 50% 50%, black 20%, transparent 70%);
  -webkit-mask-image: radial-gradient(ellipse 60% 60% at 50% 50%, black 20%, transparent 70%);
}

.hero-gradient {
  position: absolute;
  top: -20%;
  left: 50%;
  transform: translateX(-50%);
  width: 120%;
  height: 80%;
  background: radial-gradient(ellipse at center, rgba(201, 169, 110, 0.06) 0%, transparent 60%);
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  padding: 0 clamp(20px, 5vw, 48px);
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--accent);
  letter-spacing: 0.1em;
  margin-bottom: var(--space-xl);
}

.badge-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  animation: pulse-dot 2s ease-in-out infinite;
}

@keyframes pulse-dot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(1.5); }
}

.hero-title {
  font-family: var(--font-serif);
  font-size: clamp(2rem, 6vw, 3.5rem);
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: 0.02em;
  color: var(--text-primary);
  margin-bottom: var(--space-lg);
}

.hero-desc {
  font-size: clamp(0.9375rem, 1.5vw, 1.0625rem);
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: var(--space-2xl);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-md);
  flex-wrap: wrap;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  font-size: 0.875rem;
  font-weight: 600;
  font-family: var(--font-sans);
  letter-spacing: 0.04em;
  border: none;
  cursor: pointer;
  transition: all 0.3s var(--ease-out-expo);
  border-radius: 2px;
}

.btn-primary {
  background: var(--accent);
  color: var(--text-inverse);
}

.btn-primary:hover {
  background: var(--accent-light);
  transform: translateY(-1px);
}

.btn-primary svg {
  transition: transform 0.3s var(--ease-out-expo);
}

.btn-primary:hover svg {
  transform: translateX(3px);
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border);
}

.btn-ghost:hover {
  color: var(--text-primary);
  border-color: var(--border-hover);
}

/* Hero scroll indicator */
.hero-scroll {
  position: absolute;
  bottom: var(--space-2xl);
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
  color: var(--text-tertiary);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
}

.scroll-line {
  width: 1px;
  height: 40px;
  background: linear-gradient(to bottom, var(--accent), transparent);
  animation: scroll-pulse 2s ease-in-out infinite;
}

@keyframes scroll-pulse {
  0%, 100% { opacity: 1; height: 40px; }
  50% { opacity: 0.3; height: 20px; }
}

/* --- Sections --- */
.section {
  padding: var(--space-5xl) 0;
  position: relative;
}

.section-header {
  max-width: 600px;
  margin-bottom: var(--space-4xl);
}

.section-label {
  display: block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.2em;
  color: var(--accent);
  text-transform: uppercase;
  margin-bottom: var(--space-md);
}

.section-title {
  font-family: var(--font-serif);
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: 0.02em;
  margin-bottom: var(--space-lg);
}

.section-desc {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

/* --- Services --- */
.services {
  background: var(--bg-secondary);
}

.services-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-lg);
}

.service-card {
  position: relative;
  padding: var(--space-2xl);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 3px;
  transition: all 0.5s var(--ease-out-expo);
  overflow: hidden;
}

.service-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
  opacity: 0;
  transition: opacity 0.5s ease;
}

.service-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-2px);
}

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

.service-number {
  font-family: var(--font-serif);
  font-size: 0.75rem;
  color: var(--text-tertiary);
  letter-spacing: 0.1em;
  margin-bottom: var(--space-xl);
}

.service-icon {
  color: var(--accent);
  margin-bottom: var(--space-lg);
  opacity: 0.8;
}

.service-title {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: var(--space-md);
  letter-spacing: 0.05em;
}

.service-desc {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.service-line {
  position: absolute;
  bottom: 0;
  left: var(--space-2xl);
  right: var(--space-2xl);
  height: 1px;
  background: var(--border);
}

/* --- Stats --- */
.stats {
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.stats-grid {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-3xl);
  flex-wrap: wrap;
}

.stat-item {
  text-align: center;
  min-width: 120px;
}

.stat-number {
  font-family: var(--font-serif);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700;
  color: var(--accent);
  letter-spacing: -0.02em;
}

.stat-suffix {
  font-family: var(--font-serif);
  font-size: clamp(1rem, 2vw, 1.5rem);
  color: var(--accent-dim);
  margin-left: 2px;
}

.stat-label {
  display: block;
  font-size: 0.8125rem;
  color: var(--text-tertiary);
  letter-spacing: 0.1em;
  margin-top: var(--space-sm);
}

.stat-divider {
  width: 1px;
  height: 48px;
  background: var(--border);
}

/* --- Products --- */
.products-list {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.product-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-2xl) 0;
  border-bottom: 1px solid var(--border);
  transition: all 0.4s var(--ease-out-expo);
  cursor: pointer;
  gap: var(--space-xl);
}

.product-item:first-child {
  border-top: 1px solid var(--border);
}

.product-item:hover {
  padding-left: var(--space-md);
}

.product-info {
  flex: 1;
}

.product-tag {
  display: inline-block;
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  color: var(--accent);
  text-transform: uppercase;
  margin-bottom: var(--space-sm);
  padding: 3px 10px;
  border: 1px solid var(--accent-dim);
  border-radius: 2px;
}

.product-name {
  font-family: var(--font-serif);
  font-size: clamp(1.25rem, 2.5vw, 1.5rem);
  font-weight: 600;
  margin-bottom: var(--space-sm);
  letter-spacing: 0.03em;
}

.product-desc {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.6;
  max-width: 500px;
}

.product-link {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 0.8125rem;
  color: var(--text-tertiary);
  white-space: nowrap;
  transition: color 0.3s ease;
}

.product-link svg {
  transition: transform 0.3s var(--ease-out-expo);
}

.product-item:hover .product-link {
  color: var(--accent);
}

.product-item:hover .product-link svg {
  transform: translate(3px, -3px);
}

/* --- About --- */
.about {
  background: var(--bg-secondary);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: var(--space-4xl);
  align-items: start;
}

.about-text {
  font-size: 1.0625rem;
  color: var(--text-secondary);
  line-height: 2;
  margin-bottom: var(--space-lg);
}

.about-values {
  display: flex;
  gap: var(--space-2xl);
  margin-top: var(--space-2xl);
  padding-top: var(--space-2xl);
  border-top: 1px solid var(--border);
}

.value {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
}

.value-char {
  font-family: var(--font-serif);
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent);
  width: 64px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--accent-dim);
  border-radius: 2px;
}

.value-label {
  font-size: 0.8125rem;
  color: var(--text-tertiary);
  letter-spacing: 0.1em;
}

/* --- Contact --- */
.contact {
  text-align: center;
  padding: var(--space-5xl) 0;
}

.contact-inner {
  max-width: 600px;
  margin: 0 auto;
}

.contact-title {
  font-family: var(--font-serif);
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: 0.02em;
  margin-bottom: var(--space-lg);
}

.contact-desc {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: var(--space-2xl);
}

.contact-email {
  display: inline-flex;
  align-items: center;
  gap: var(--space-md);
  font-family: var(--font-serif);
  font-size: clamp(1.125rem, 2.5vw, 1.5rem);
  font-weight: 600;
  color: var(--accent);
  padding: var(--space-lg) var(--space-2xl);
  border: 1px solid var(--accent-dim);
  border-radius: 2px;
  transition: all 0.4s var(--ease-out-expo);
}

.contact-email:hover {
  background: var(--accent);
  color: var(--text-inverse);
  border-color: var(--accent);
}

.contact-email svg {
  transition: transform 0.3s var(--ease-out-expo);
}

.contact-email:hover svg {
  transform: translate(3px, -3px);
}

/* --- Footer --- */
.footer {
  border-top: 1px solid var(--border);
  padding: var(--space-2xl) 0;
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-lg);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 8px;
}

.footer-links {
  display: flex;
  gap: var(--space-xl);
}

.footer-links a {
  font-size: 0.8125rem;
  color: var(--text-tertiary);
  transition: color 0.3s ease;
}

.footer-links a:hover {
  color: var(--text-secondary);
}

.footer-legal {
  display: flex;
  gap: var(--space-lg);
  width: 100%;
  justify-content: center;
}

.footer-legal a {
  font-size: 0.75rem;
  color: var(--text-tertiary);
  transition: color 0.3s ease;
}

.police-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.police-icon {
  width: 16px;
  height: 16px;
  object-fit: contain;
}

.footer-legal a:hover {
  color: var(--text-secondary);
}

.footer-copy {
  width: 100%;
  text-align: center;
  font-size: 0.75rem;
  color: var(--text-tertiary);
  margin-top: var(--space-sm);
}

/* --- Reveal Animation --- */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s var(--ease-out-expo), transform 0.7s var(--ease-out-expo);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger delays via data-delay */
.reveal[data-delay="1"] { transition-delay: 0.08s; }
.reveal[data-delay="2"] { transition-delay: 0.16s; }
.reveal[data-delay="3"] { transition-delay: 0.24s; }
.reveal[data-delay="4"] { transition-delay: 0.32s; }
.reveal[data-delay="5"] { transition-delay: 0.40s; }

/* --- Reduced Motion --- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }

  html {
    scroll-behavior: auto;
  }
}

/* --- Responsive --- */
@media (max-width: 900px) {
  .services-grid {
    grid-template-columns: 1fr;
  }

  .about-grid {
    grid-template-columns: 1fr;
    gap: var(--space-2xl);
  }

  .stats-grid {
    gap: var(--space-xl);
  }

  .stat-divider {
    display: none;
  }

  .stats-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-2xl);
  }
}

@media (max-width: 640px) {
  .nav-links {
    display: none;
  }

  .nav-toggle {
    display: block;
  }

  .hero {
    min-height: 100svh;
  }

  .hero-title {
    font-size: clamp(1.75rem, 8vw, 2.5rem);
  }

  .hide-mobile {
    display: none;
  }

  .product-item {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-md);
  }

  .product-link {
    align-self: flex-end;
  }

  .about-values {
    gap: var(--space-lg);
  }

  .value-char {
    width: 52px;
    height: 52px;
    font-size: 1.5rem;
  }

  .footer-inner {
    flex-direction: column;
    text-align: center;
  }

  .footer-links {
    gap: var(--space-lg);
  }

  .service-card {
    padding: var(--space-xl);
  }
}

/* --- Section separator line --- */
.services::before,
.products::before,
.about::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: min(80%, 200px);
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--accent-dim), transparent);
  opacity: 0.3;
}