/* ============================================
   云梦智能官网 - NVIDIA 风格：黑绿科技
   AI 基础设施感、算力和智能平台表达
   ============================================ */

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

:root {
  /* NVIDIA-inspired color system */
  --color-bg: #0a0a0a;
  --color-bg-elevated: #111111;
  --color-bg-card: #161616;
  --color-bg-card-hover: #1a1a1a;
  --color-surface: #1e1e1e;
  --color-border: #2a2a2a;
  --color-border-light: #333333;

  /* Green accent - NVIDIA inspired but distinct */
  --color-primary: #76b900;
  --color-primary-light: #8ed100;
  --color-primary-dark: #5a8f00;
  --color-primary-glow: rgba(118, 185, 0, 0.15);
  --color-primary-glow-strong: rgba(118, 185, 0, 0.3);

  /* Text */
  --color-text: #e8e8e8;
  --color-text-secondary: #999999;
  --color-text-muted: #666666;

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
  --font-mono: "SF Mono", "Fira Code", "Fira Mono", "Roboto Mono", monospace;

  /* Spacing */
  --container-max: 1280px;
  --section-padding: 100px;
  --section-padding-mobile: 60px;

  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-base: 0.3s ease;
  --transition-slow: 0.5s ease;
}

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

body {
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}

/* --- Header --- */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(10, 10, 10, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--color-border);
  transition: background var(--transition-base);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo img {
  height: 36px;
  width: auto;
}

.logo-text {
  font-size: 18px;
  font-weight: 600;
  letter-spacing: 0.5px;
}

.nav {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-link {
  font-size: 14px;
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: color var(--transition-fast);
  position: relative;
}

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

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--color-primary);
  border-radius: 1px;
}

/* Dropdown */
.nav-dropdown {
  position: relative;
}

.dropdown-menu {
  position: absolute;
  top: 100%;
  left: 0;
  padding-top: 16px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: all var(--transition-fast);
}

.nav-dropdown:hover .dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.dropdown-item {
  display: block;
  padding: 10px 16px;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  font-size: 14px;
  white-space: nowrap;
  margin-bottom: 4px;
}

.dropdown-item:hover {
  background: var(--color-bg-card-hover);
  color: var(--color-primary);
}

.header-actions {
  display: flex;
  align-items: center;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  transition: all var(--transition-fast);
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-sans);
  font-weight: 600;
  border-radius: 8px;
  cursor: pointer;
  transition: all var(--transition-fast);
  border: none;
  text-align: center;
}

.btn-primary {
  background: var(--color-primary);
  color: #000;
  padding: 12px 28px;
  font-size: 15px;
}

.btn-primary:hover {
  background: var(--color-primary-light);
  box-shadow: 0 0 24px var(--color-primary-glow-strong);
}

.btn-outline {
  background: transparent;
  color: var(--color-text);
  padding: 12px 28px;
  font-size: 15px;
  border: 1px solid var(--color-border-light);
}

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

.btn-ghost {
  border-color: transparent;
}

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

.btn-sm {
  padding: 8px 20px;
  font-size: 13px;
}

.btn-lg {
  padding: 16px 40px;
  font-size: 17px;
}

/* --- Hero Section --- */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 72px;
  overflow: hidden;
}

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

.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(118, 185, 0, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(118, 185, 0, 0.03) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse at center, black 30%, transparent 70%);
  -webkit-mask-image: radial-gradient(ellipse at center, black 30%, transparent 70%);
}

.hero-glow {
  position: absolute;
  top: 20%;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 600px;
  background: radial-gradient(ellipse, var(--color-primary-glow) 0%, transparent 70%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 900px;
}

.hero-badge {
  display: inline-block;
  padding: 8px 20px;
  background: var(--color-primary-glow);
  border: 1px solid rgba(118, 185, 0, 0.2);
  border-radius: 100px;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-primary);
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-bottom: 32px;
}

.hero-title {
  font-size: clamp(36px, 5vw, 64px);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: 24px;
  background: linear-gradient(135deg, #ffffff 0%, #cccccc 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: clamp(16px, 2vw, 19px);
  color: var(--color-text-secondary);
  line-height: 1.7;
  max-width: 720px;
  margin: 0 auto 40px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  margin-bottom: 64px;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  padding-top: 48px;
  border-top: 1px solid var(--color-border);
}

.stat {
  text-align: center;
}

.stat-value {
  display: block;
  font-size: clamp(28px, 3vw, 42px);
  font-weight: 700;
  color: var(--color-primary);
  font-family: var(--font-mono);
  letter-spacing: -0.02em;
}

.stat-label {
  display: block;
  font-size: 13px;
  color: var(--color-text-muted);
  margin-top: 8px;
}

/* --- Sections --- */
.section {
  padding: var(--section-padding) 0;
}

.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 64px;
}

.section-tag {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  color: var(--color-primary);
  letter-spacing: 2px;
  text-transform: uppercase;
  margin-bottom: 16px;
}

.section-title {
  font-size: clamp(28px, 3.5vw, 44px);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.01em;
  margin-bottom: 16px;
}

.section-desc {
  font-size: 17px;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* --- About Section --- */
.section-about {
  background: var(--color-bg-elevated);
}

.about-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.about-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: 16px;
  padding: 32px 24px;
  transition: all var(--transition-base);
}

.about-card:hover {
  border-color: var(--color-primary);
  transform: translateY(-4px);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.about-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary);
  margin-bottom: 20px;
}

.about-icon svg {
  width: 100%;
  height: 100%;
}

.about-card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 12px;
}

.about-card p {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* --- Features Section --- */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: 16px;
  padding: 36px 28px;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--color-primary), transparent);
  opacity: 0;
  transition: opacity var(--transition-base);
}

.feature-card:hover {
  border-color: var(--color-border-light);
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.4);
}

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

.feature-icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  margin-bottom: 24px;
  color: var(--color-primary);
}

.feature-icon svg {
  width: 32px;
  height: 32px;
}

.feature-icon-1 { background: rgba(118, 185, 0, 0.1); }
.feature-icon-2 { background: rgba(118, 185, 0, 0.1); }
.feature-icon-3 { background: rgba(118, 185, 0, 0.1); }
.feature-icon-4 { background: rgba(118, 185, 0, 0.1); }
.feature-icon-5 { background: rgba(118, 185, 0, 0.1); }

.feature-card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 12px;
  line-height: 1.4;
}

.feature-card p {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* --- Products Section --- */
.section-products {
  background: var(--color-bg-elevated);
}

.products-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.product-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: 20px;
  padding: 40px 32px;
  position: relative;
  transition: all var(--transition-base);
}

.product-card:hover {
  border-color: var(--color-primary);
  box-shadow: 0 0 40px var(--color-primary-glow);
}

.product-badge {
  display: inline-block;
  padding: 6px 14px;
  background: var(--color-primary);
  color: #000;
  font-size: 12px;
  font-weight: 700;
  border-radius: 6px;
  margin-bottom: 20px;
  letter-spacing: 0.5px;
}

.product-badge-lite {
  background: var(--color-surface);
  color: var(--color-text-secondary);
  border: 1px solid var(--color-border-light);
}

.product-card h3 {
  font-size: 26px;
  font-weight: 700;
  margin-bottom: 12px;
}

.product-desc {
  font-size: 15px;
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: 28px;
}

.product-features {
  list-style: none;
  margin-bottom: 32px;
}

.product-features li {
  padding: 10px 0;
  font-size: 14px;
  color: var(--color-text-secondary);
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: flex-start;
  gap: 10px;
}

.product-features li:last-child {
  border-bottom: none;
}

.product-features li::before {
  content: '';
  flex-shrink: 0;
  width: 6px;
  height: 6px;
  background: var(--color-primary);
  border-radius: 50%;
  margin-top: 8px;
}

.product-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

/* --- Trust Section --- */
.trust-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.trust-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: 16px;
  padding: 36px 32px;
  text-align: center;
  transition: all var(--transition-base);
}

.trust-card:hover {
  border-color: var(--color-border-light);
  transform: translateY(-4px);
}

.trust-logo {
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
}

.trust-logo img {
  max-height: 48px;
  width: auto;
  filter: brightness(0) invert(1);
  opacity: 0.8;
}

.trust-card h3 {
  font-size: 22px;
  font-weight: 600;
  margin-bottom: 16px;
}

.trust-card p {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.7;
  max-width: 480px;
  margin: 0 auto;
}

/* --- Team Section --- */
.section-team {
  background: var(--color-bg-elevated);
}

.team-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.team-card {
  text-align: center;
  padding: 28px 16px;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: 16px;
  transition: all var(--transition-base);
}

.team-card:hover {
  border-color: var(--color-border-light);
  transform: translateY(-4px);
}

.team-avatar {
  width: 96px;
  height: 96px;
  border-radius: 50%;
  overflow: hidden;
  margin: 0 auto 16px;
  border: 2px solid var(--color-border);
}

.team-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.team-card h4 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 6px;
}

.team-role {
  font-size: 13px;
  color: var(--color-text-muted);
}

/* --- CTA Section --- */
.section-cta {
  background: linear-gradient(180deg, var(--color-bg) 0%, var(--color-bg-elevated) 100%);
  text-align: center;
}

.cta-content {
  max-width: 640px;
  margin: 0 auto;
}

.cta-title {
  font-size: clamp(28px, 3.5vw, 40px);
  font-weight: 700;
  margin-bottom: 16px;
  line-height: 1.25;
}

.cta-desc {
  font-size: 17px;
  color: var(--color-text-secondary);
  margin-bottom: 36px;
}

.cta-actions {
  margin-bottom: 40px;
}

.cta-qr {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.cta-qr img {
  width: 140px;
  height: 140px;
  border-radius: 12px;
  border: 1px solid var(--color-border);
  background: #fff;
  padding: 8px;
}

.cta-qr span {
  font-size: 13px;
  color: var(--color-text-muted);
}

/* --- Footer --- */
.footer {
  background: var(--color-bg-elevated);
  border-top: 1px solid var(--color-border);
  padding: 64px 0 32px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 48px;
}

.footer-brand .logo {
  margin-bottom: 16px;
}

.footer-brand p {
  font-size: 14px;
  color: var(--color-text-secondary);
  margin-bottom: 8px;
}

.footer-desc {
  font-size: 13px !important;
  color: var(--color-text-muted) !important;
}

.footer-nav h4 {
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 16px;
  color: var(--color-text);
}

.footer-nav a {
  display: block;
  font-size: 14px;
  color: var(--color-text-secondary);
  padding: 6px 0;
}

.footer-nav a:hover {
  color: var(--color-primary);
}

.footer-contact {
  font-size: 14px;
  color: var(--color-text-muted);
}

.footer-qr {
  margin-top: 12px;
}

.footer-qr img {
  width: 80px;
  height: 80px;
  border-radius: 8px;
  background: #fff;
  padding: 4px;
}

.footer-bottom {
  padding-top: 32px;
  border-top: 1px solid var(--color-border);
  text-align: center;
}

.footer-bottom p {
  font-size: 13px;
  color: var(--color-text-muted);
}

/* ============================================
   Responsive Design
   ============================================ */

@media (max-width: 1024px) {
  :root {
    --section-padding: 80px;
  }

  .about-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .team-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  :root {
    --section-padding: var(--section-padding-mobile);
  }

  .nav {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--color-bg);
    flex-direction: column;
    align-items: flex-start;
    padding: 32px 24px;
    gap: 24px;
    transform: translateX(100%);
    transition: transform var(--transition-base);
  }

  .nav.open {
    transform: translateX(0);
  }

  .nav-dropdown .dropdown-menu {
    position: static;
    opacity: 1;
    visibility: visible;
    transform: none;
    padding-top: 12px;
    padding-left: 16px;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-toggle.open span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
  }

  .nav-toggle.open span:nth-child(2) {
    opacity: 0;
  }

  .nav-toggle.open span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
  }

  .header-actions {
    display: none;
  }

  .hero {
    min-height: auto;
    padding-top: 120px;
    padding-bottom: 60px;
  }

  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
  }

  .hero-actions {
    flex-direction: column;
    align-items: center;
  }

  .about-grid {
    grid-template-columns: 1fr;
  }

  .features-grid {
    grid-template-columns: 1fr;
  }

  .products-grid {
    grid-template-columns: 1fr;
  }

  .trust-grid {
    grid-template-columns: 1fr;
  }

  .team-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }

  .hero-title {
    font-size: 28px;
  }

  .hero-subtitle {
    font-size: 15px;
  }

  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }

  .stat-value {
    font-size: 24px;
  }

  .section-title {
    font-size: 24px;
  }

  .team-grid {
    grid-template-columns: 1fr;
  }

  .product-card {
    padding: 28px 20px;
  }

  .product-actions {
    flex-direction: column;
  }

  .product-actions .btn {
    width: 100%;
  }
}