/* ========================================
   云梦智能 — Tesla-inspired Enterprise Site
   Design: Full-screen immersive, high contrast,
   minimal decoration, strong CTAs, speed feel
   ======================================== */

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

:root {
  --color-bg: #0a0a0a;
  --color-bg-alt: #111111;
  --color-bg-card: #1a1a1a;
  --color-text: #f0f0f0;
  --color-text-secondary: #8a8a8a;
  --color-accent: #e8e8e8;
  --color-primary: #ffffff;
  --color-border: #2a2a2a;
  --color-highlight: #3b82f6;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  --max-width: 1200px;
  --nav-height: 64px;
  --section-padding: 120px;
}

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;
}

ul {
  list-style: none;
}

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

/* --- Navigation --- */
.nav {
  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 rgba(255, 255, 255, 0.06);
  transition: background 0.3s ease;
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 32px;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  font-size: 1rem;
  letter-spacing: 0.02em;
}

.nav-logo {
  height: 32px;
  width: auto;
}

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

.nav-links {
  display: flex;
  gap: 36px;
}

.nav-links a {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  transition: color 0.2s ease;
  font-weight: 400;
}

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

.nav-cta {
  font-size: 0.875rem;
  font-weight: 500;
  padding: 8px 20px;
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: 4px;
  transition: all 0.2s ease;
}

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

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: var(--color-text);
  transition: all 0.3s ease;
}

.nav-mobile {
  display: none;
  position: absolute;
  top: var(--nav-height);
  left: 0;
  right: 0;
  background: rgba(10, 10, 10, 0.98);
  backdrop-filter: blur(20px);
  padding: 24px 32px;
  border-bottom: 1px solid var(--color-border);
}

.nav-mobile.active {
  display: block;
}

.nav-mobile ul {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.nav-mobile a {
  font-size: 1rem;
  color: var(--color-text-secondary);
  display: block;
  padding: 8px 0;
}

.mobile-cta {
  color: var(--color-primary) !important;
  font-weight: 500;
}

/* --- Hero Section --- */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: calc(var(--nav-height) + 40px) 32px 80px;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 50% 40%, rgba(59, 130, 246, 0.08) 0%, transparent 70%),
    radial-gradient(ellipse 60% 80% at 80% 20%, rgba(139, 92, 246, 0.05) 0%, transparent 60%),
    var(--color-bg);
  z-index: 0;
}

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

.hero-title {
  font-size: clamp(3rem, 8vw, 6.5rem);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin-bottom: 28px;
}

.hero-line {
  display: block;
}

.hero-line:first-child {
  background: linear-gradient(135deg, #ffffff 0%, #a5b4fc 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-line:last-child {
  color: var(--color-primary);
}

.hero-subtitle {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: var(--color-text-secondary);
  max-width: 640px;
  margin: 0 auto 44px;
  line-height: 1.7;
  font-weight: 300;
}

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

.hero-scroll {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--color-text-secondary);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  animation: scrollBounce 2s ease-in-out infinite;
}

@keyframes scrollBounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(8px); }
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  font-size: 0.9375rem;
  font-weight: 500;
  border-radius: 4px;
  transition: all 0.25s ease;
  cursor: pointer;
  min-width: 140px;
}

.btn-primary {
  background: var(--color-primary);
  color: var(--color-bg);
  border: 1px solid var(--color-primary);
}

.btn-primary:hover {
  background: #e0e0e0;
  transform: translateY(-1px);
}

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

.btn-secondary:hover {
  border-color: var(--color-text-secondary);
  background: rgba(255, 255, 255, 0.04);
}

/* --- Stats Section --- */
.stats {
  background: var(--color-bg-alt);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
  padding: 56px 32px;
}

.stats-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 48px;
}

.stat-item {
  text-align: center;
}

.stat-number {
  display: block;
  font-size: clamp(2rem, 4vw, 3.5rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--color-primary);
  line-height: 1.1;
}

.stat-label {
  display: block;
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  margin-top: 8px;
  font-weight: 400;
}

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

/* --- Section Common --- */
.section-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--section-padding) 32px;
}

.section-header {
  text-align: center;
  margin-bottom: 72px;
}

.section-title {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
  color: var(--color-primary);
}

.section-desc {
  font-size: 1.0625rem;
  color: var(--color-text-secondary);
  max-width: 560px;
  margin: 0 auto;
  line-height: 1.7;
}

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

.product-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.product-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 40px 32px;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.product-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(59, 130, 246, 0.4), transparent);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.product-card:hover {
  border-color: rgba(59, 130, 246, 0.3);
  transform: translateY(-4px);
}

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

.product-card--featured {
  border-color: rgba(59, 130, 246, 0.2);
  background: linear-gradient(180deg, rgba(59, 130, 246, 0.06) 0%, var(--color-bg-card) 40%);
}

.product-card-visual {
  margin-bottom: 28px;
}

.product-card-icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  background: rgba(59, 130, 246, 0.08);
  color: var(--color-highlight);
}

.product-card-title {
  font-size: 1.375rem;
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--color-primary);
  letter-spacing: -0.01em;
}

.product-card-desc {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
  margin-bottom: 24px;
}

.product-card-features {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.product-card-features li {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  padding-left: 18px;
  position: relative;
}

.product-card-features li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-highlight);
  opacity: 0.6;
}

/* --- Capabilities Section --- */
.capabilities {
  background: var(--color-bg-alt);
  border-top: 1px solid var(--color-border);
}

.capabilities-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}

.capability-item {
  text-align: center;
  padding: 32px 20px;
  border-radius: 8px;
  transition: all 0.3s ease;
}

.capability-item:hover {
  background: rgba(255, 255, 255, 0.03);
}

.capability-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.04);
  color: var(--color-text);
}

.capability-item h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 10px;
  color: var(--color-primary);
}

.capability-item p {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  line-height: 1.65;
}

/* --- Ecosystem Section --- */
.ecosystem {
  background: var(--color-bg);
  border-top: 1px solid var(--color-border);
}

.ecosystem-logos {
  display: flex;
  justify-content: center;
  gap: 64px;
  margin-bottom: 40px;
  flex-wrap: wrap;
}

.ecosystem-logo {
  width: 160px;
  height: 80px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 16px;
  transition: all 0.3s ease;
}

.ecosystem-logo:hover {
  border-color: rgba(255, 255, 255, 0.15);
}

.ecosystem-logo img {
  max-height: 40px;
  width: auto;
  opacity: 0.85;
  filter: brightness(0) invert(1);
}

.ecosystem-note {
  text-align: center;
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.7;
}

/* --- About Section --- */
.about {
  background: var(--color-bg-alt);
  border-top: 1px solid var(--color-border);
}

.about .section-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.about .section-header {
  text-align: left;
  margin-bottom: 32px;
}

.about-text p {
  font-size: 1rem;
  color: var(--color-text-secondary);
  line-height: 1.8;
  margin-bottom: 16px;
}

.about-text p:last-child {
  margin-bottom: 0;
}

.about-visual {
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid var(--color-border);
}

.about-visual img {
  width: 100%;
  height: auto;
  display: block;
}

/* --- Contact Section --- */
.contact {
  background: var(--color-bg);
  border-top: 1px solid var(--color-border);
  text-align: center;
}

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

.contact-title {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
  color: var(--color-primary);
}

.contact-desc {
  font-size: 1.0625rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
  margin-bottom: 36px;
}

.contact-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 24px;
}

.contact-note {
  font-size: 0.8125rem;
  color: var(--color-text-secondary);
  opacity: 0.6;
}

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

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  margin-bottom: 48px;
}

.footer-logo {
  height: 28px;
  width: auto;
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 48px;
  margin-bottom: 48px;
}

.footer-col h4 {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 16px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-col a {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  transition: color 0.2s ease;
}

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

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

.footer-bottom p {
  font-size: 0.8125rem;
  color: var(--color-text-secondary);
  opacity: 0.6;
}

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

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

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

  .about .section-inner {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .about .section-header {
    text-align: center;
    margin-bottom: 32px;
  }

  .about-visual {
    order: -1;
  }
}

@media (max-width: 768px) {
  :root {
    --section-padding: 64px;
  }

  .nav-links,
  .nav-cta {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }

  .hero {
    min-height: 90vh;
    padding-top: calc(var(--nav-height) + 24px);
  }

  .hero-title {
    font-size: clamp(2.5rem, 10vw, 3.5rem);
  }

  .hero-subtitle {
    font-size: 1rem;
    margin-bottom: 32px;
  }

  .hero-actions {
    flex-direction: column;
    align-items: center;
    width: 100%;
  }

  .btn {
    width: 100%;
    max-width: 280px;
  }

  .hero-scroll {
    display: none;
  }

  .stats-inner {
    flex-direction: column;
    gap: 32px;
  }

  .stat-divider {
    width: 48px;
    height: 1px;
  }

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

  .capabilities-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .capability-item {
    display: flex;
    text-align: left;
    gap: 20px;
    padding: 24px;
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: 8px;
  }

  .capability-icon {
    margin: 0;
    flex-shrink: 0;
  }

  .ecosystem-logos {
    gap: 24px;
  }

  .ecosystem-logo {
    width: 140px;
    height: 64px;
  }

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

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

@media (max-width: 480px) {
  .nav-inner {
    padding: 0 20px;
  }

  .section-inner {
    padding: var(--section-padding) 20px;
  }

  .product-card {
    padding: 28px 24px;
  }

  .stats {
    padding: 40px 20px;
  }
}

/* --- Animations --- */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- Selection --- */
::selection {
  background: rgba(59, 130, 246, 0.3);
  color: var(--color-primary);
}

/* --- Scrollbar --- */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--color-bg);
}

::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: #3a3a3a;
}