:root {
  --bg-deep: #0a0e17;
  --bg-card: rgba(15, 23, 42, 0.72);
  --bg-elevated: rgba(30, 41, 59, 0.6);
  --border: rgba(148, 163, 184, 0.12);
  --text: #e2e8f0;
  --text-muted: #94a3b8;
  --accent: #38bdf8;
  --accent-2: #818cf8;
  --accent-glow: rgba(56, 189, 248, 0.35);
  --success: #34d399;
  --warning: #fbbf24;
  --radius: 16px;
  --radius-sm: 10px;
  --font: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", -apple-system, BlinkMacSystemFont, sans-serif;
  --mono: "JetBrains Mono", "SF Mono", Consolas, monospace;
}

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

html {
  scroll-behavior: smooth;
}

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

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

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

.container {
  width: min(1180px, calc(100% - 48px));
  margin: 0 auto;
}

/* Background */
.bg-grid {
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(56, 189, 248, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(56, 189, 248, 0.03) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, black, transparent);
  pointer-events: none;
  z-index: 0;
}

.bg-glow {
  position: fixed;
  width: 600px;
  height: 600px;
  border-radius: 50%;
  filter: blur(120px);
  opacity: 0.25;
  pointer-events: none;
  z-index: 0;
}

.bg-glow-1 {
  top: -200px;
  left: -100px;
  background: #38bdf8;
}

.bg-glow-2 {
  top: 200px;
  right: -150px;
  background: #818cf8;
}

/* Nav */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 16px 0;
  transition: background 0.3s, backdrop-filter 0.3s, border-color 0.3s;
}

.nav.scrolled {
  background: rgba(10, 14, 23, 0.85);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  font-size: 1.25rem;
}

.logo-icon {
  width: 40px;
  height: 40px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.nav-links a {
  color: var(--text-muted);
  font-size: 0.95rem;
  transition: color 0.2s;
}

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

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

.nav-user-name {
  color: var(--text-muted);
  font-size: 0.9rem;
  max-width: 120px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.mobile-auth {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 8px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
}

.mobile-auth .nav-user-name {
  padding: 4px 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s, background 0.2s;
  font-family: inherit;
}

.btn:active {
  transform: scale(0.98);
}

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

.btn-ghost:hover {
  color: var(--text);
  border-color: rgba(148, 163, 184, 0.3);
  background: var(--bg-elevated);
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #0a0e17;
  box-shadow: 0 4px 24px var(--accent-glow);
}

.btn-primary:hover {
  box-shadow: 0 6px 32px var(--accent-glow);
}

.btn-lg {
  padding: 14px 28px;
  font-size: 1rem;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text);
  cursor: pointer;
  padding: 8px;
}

/* Hero */
.hero {
  position: relative;
  z-index: 1;
  padding: 160px 0 100px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
  overflow: visible;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 999px;
  font-size: 0.85rem;
  color: var(--accent);
  margin-bottom: 24px;
}

.hero-badge-dot {
  width: 8px;
  height: 8px;
  background: var(--success);
  border-radius: 50%;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

.hero h1 {
  font-size: clamp(2.5rem, 5vw, 3.75rem);
  line-height: 1.15;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
}

.hero h1 span {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  font-size: 1.15rem;
  color: var(--text-muted);
  max-width: 520px;
  margin-bottom: 36px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 48px;
}

.hero-stats {
  display: flex;
  gap: 40px;
}

.stat-value {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--text);
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Hero mockup */
.hero-visual {
  position: relative;
  overflow: visible;
  isolation: isolate;
  padding: 24px 36px 24px 28px;
}

.mockup-window {
  position: relative;
  z-index: 1;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  backdrop-filter: blur(20px);
  box-shadow:
    0 0 0 1px rgba(255, 255, 255, 0.05),
    0 24px 80px rgba(0, 0, 0, 0.5);
}

.hero-floats {
  position: absolute;
  inset: 0;
  z-index: 10;
  pointer-events: none;
}

.mockup-titlebar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 14px 18px;
  background: rgba(0, 0, 0, 0.3);
  border-bottom: 1px solid var(--border);
}

.mockup-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}

.mockup-dot.red { background: #ef4444; }
.mockup-dot.yellow { background: #fbbf24; }
.mockup-dot.green { background: #34d399; }

.mockup-url {
  flex: 1;
  margin-left: 12px;
  padding: 6px 14px;
  background: rgba(0, 0, 0, 0.3);
  border-radius: 6px;
  font-size: 0.8rem;
  color: var(--text-muted);
  font-family: var(--mono);
}

.mockup-body {
  padding: 20px;
}

.file-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.file-item {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 12px 14px;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid transparent;
  transition: border-color 0.2s, background 0.2s;
}

.file-item:hover {
  border-color: var(--border);
  background: rgba(56, 189, 248, 0.05);
}

.file-icon {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  flex-shrink: 0;
}

.file-icon.apk { background: rgba(52, 211, 153, 0.15); }
.file-icon.zip { background: rgba(251, 191, 36, 0.15); }
.file-icon.pdf { background: rgba(239, 68, 68, 0.15); }
.file-icon.img { background: rgba(129, 140, 248, 0.15); }

.file-info {
  flex: 1;
  min-width: 0;
}

.file-name {
  font-size: 0.9rem;
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.file-meta {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.file-action {
  font-size: 0.8rem;
  color: var(--accent);
  opacity: 0;
  transition: opacity 0.2s;
}

.file-item:hover .file-action {
  opacity: 1;
}

.floating-card {
  position: absolute;
  background: #1a2332;
  border: 1px solid rgba(56, 189, 248, 0.28);
  border-radius: var(--radius-sm);
  padding: 14px 18px;
  box-shadow:
    0 0 0 1px rgba(255, 255, 255, 0.04),
    0 16px 48px rgba(0, 0, 0, 0.55);
  animation: float 4s ease-in-out infinite;
  will-change: transform;
}

.floating-card-1 {
  top: -18px;
  right: -28px;
}

.floating-card-2 {
  bottom: 36px;
  left: -36px;
  animation-delay: -2s;
}

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

.floating-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.floating-value {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--success);
}

/* Sections */
section {
  position: relative;
  z-index: 1;
  padding: 100px 0;
}

.section-header {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 64px;
}

.section-tag {
  display: inline-block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 12px;
}

.section-header h2 {
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: 800;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.section-header p {
  color: var(--text-muted);
  font-size: 1.05rem;
}

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

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  backdrop-filter: blur(12px);
  transition: border-color 0.3s, transform 0.3s;
}

.feature-card:hover {
  border-color: rgba(56, 189, 248, 0.3);
  transform: translateY(-4px);
}

.feature-icon {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 20px;
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.15), rgba(129, 140, 248, 0.15));
}

.feature-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.feature-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* Use cases */
.usecases-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.usecase-card {
  display: flex;
  gap: 24px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  backdrop-filter: blur(12px);
}

.usecase-num {
  font-size: 2.5rem;
  font-weight: 800;
  line-height: 1;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  opacity: 0.5;
}

.usecase-card h3 {
  font-size: 1.2rem;
  margin-bottom: 8px;
}

.usecase-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

.usecase-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 14px;
}

.tag {
  padding: 4px 10px;
  background: rgba(56, 189, 248, 0.1);
  border: 1px solid rgba(56, 189, 248, 0.2);
  border-radius: 6px;
  font-size: 0.75rem;
  color: var(--accent);
}

/* Apps section */
.apps-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.apps-grid-single {
  grid-template-columns: 1fr;
  max-width: 400px;
  margin: 0 auto;
}

.app-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color 0.3s, transform 0.3s;
}

.app-card:hover {
  border-color: rgba(56, 189, 248, 0.3);
  transform: translateY(-4px);
}

.app-cover {
  height: 140px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.1), rgba(129, 140, 248, 0.1));
}

.app-body {
  padding: 24px;
}

.app-body h3 {
  font-size: 1.1rem;
  margin-bottom: 6px;
}

.app-body p {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 16px;
}

.app-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.app-download {
  color: var(--accent);
  font-weight: 600;
}

/* Pricing */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  align-items: start;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px;
  backdrop-filter: blur(12px);
}

.pricing-card.featured {
  border-color: rgba(56, 189, 248, 0.4);
  box-shadow: 0 0 60px rgba(56, 189, 248, 0.1);
  position: relative;
}

.pricing-badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  padding: 4px 16px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #0a0e17;
  font-size: 0.75rem;
  font-weight: 700;
  border-radius: 999px;
}

.pricing-card h3 {
  font-size: 1.1rem;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.pricing-price {
  font-size: 2.5rem;
  font-weight: 800;
  margin-bottom: 4px;
}

.pricing-price span {
  font-size: 1rem;
  font-weight: 400;
  color: var(--text-muted);
}

.pricing-desc {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 28px;
  padding-bottom: 28px;
  border-bottom: 1px solid var(--border);
}

.pricing-features {
  list-style: none;
  margin-bottom: 28px;
}

.pricing-features li {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 0;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.pricing-features li::before {
  content: "✓";
  color: var(--success);
  font-weight: 700;
}

.pricing-card .btn {
  width: 100%;
}

/* CTA */
.cta {
  padding: 80px 0;
}

.cta-box {
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.12), rgba(129, 140, 248, 0.12));
  border: 1px solid rgba(56, 189, 248, 0.2);
  border-radius: calc(var(--radius) + 8px);
  padding: 64px;
  text-align: center;
}

.cta-box h2 {
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 16px;
}

.cta-box p {
  color: var(--text-muted);
  max-width: 480px;
  margin: 0 auto 32px;
}

/* Footer */
.footer {
  position: relative;
  z-index: 1;
  border-top: 1px solid var(--border);
  padding: 64px 0 32px;
}

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

.footer-brand p {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-top: 16px;
  max-width: 280px;
}

.footer-col h4 {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 16px;
}

.footer-col ul {
  list-style: none;
}

.footer-col li {
  margin-bottom: 10px;
}

.footer-col a {
  color: var(--text-muted);
  font-size: 0.9rem;
  transition: color 0.2s;
}

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

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 32px;
  border-top: 1px solid var(--border);
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Mobile nav */
.mobile-menu {
  display: none;
  position: fixed;
  inset: 0;
  top: 72px;
  background: rgba(10, 14, 23, 0.98);
  backdrop-filter: blur(20px);
  z-index: 99;
  padding: 24px;
  flex-direction: column;
  gap: 8px;
}

.mobile-menu.open {
  display: flex;
}

.mobile-menu a {
  padding: 14px 16px;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  font-size: 1rem;
}

.mobile-menu a:hover {
  background: var(--bg-elevated);
  color: var(--text);
}

.mobile-menu .btn {
  margin-top: 16px;
}

/* Responsive */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 48px;
  }

  .hero-visual {
    order: -1;
    max-width: 520px;
    margin: 0 auto;
    padding: 20px 32px 20px 20px;
  }

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

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

@media (max-width: 768px) {
  .nav-links,
  .nav-actions {
    display: none;
  }

  .menu-toggle {
    display: block;
  }

  .hero {
    padding: 120px 0 60px;
  }

  .hero-stats {
    gap: 24px;
  }

  .features-grid,
  .usecases-grid,
  .apps-grid,
  .pricing-grid {
    grid-template-columns: 1fr;
  }

  .floating-card {
    display: none;
  }

  .cta-box {
    padding: 40px 24px;
  }

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

  .footer-bottom {
    flex-direction: column;
    gap: 12px;
    text-align: center;
  }
}