:root {
  --color-primary: #2563EB;
  --color-primary-dark: #1D4ED8;
  --color-primary-light: #3B82F6;
  --color-background: #FFFFFF;
  --color-surface: #F8FAFC;
  --color-surface-elevated: #FFFFFF;
  --color-border: #E2E8F0;
  --color-text-primary: #0F172A;
  --color-text-secondary: #475569;
  --color-text-muted: #94A3B8;
  --color-accent-gradient-start: #2563EB;
  --color-accent-gradient-end: #7C3AED;
  --color-success: #10B981;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --shadow-glow: 0 0 20px rgba(37, 99, 235, 0.15);
  --radius-sm: 0.375rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, 'Courier New', monospace;
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
}

* {
  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);
  color: var(--color-text-primary);
  background-color: var(--color-background);
  line-height: 1.6;
}

.container {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Header */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-text-primary);
  text-decoration: none;
}

.logo svg {
  width: 2rem;
  height: 2rem;
  color: var(--color-primary);
}

.nav-desktop {
  display: none;
}

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

.nav-desktop a {
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
  transition: color var(--transition-fast);
}

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

.lang-switcher {
  display: none;
  align-items: center;
  gap: 0.25rem;
}

.lang-switcher a {
  padding: 0.25rem 0.5rem;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-text-muted);
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.lang-switcher a:hover,
.lang-switcher a.active {
  color: var(--color-primary);
  background: rgba(37, 99, 235, 0.1);
}

/* Mobile Menu */
.mobile-menu-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--color-text-primary);
}

.mobile-menu-btn svg {
  width: 1.5rem;
  height: 1.5rem;
}

.mobile-nav {
  display: none;
  position: fixed;
  top: 4rem;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(16px);
  z-index: 99;
  padding: 2rem 1.5rem;
  flex-direction: column;
  gap: 1.5rem;
  overflow-y: auto;
}

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

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

.mobile-nav a {
  display: block;
  padding: 0.75rem 0;
  color: var(--color-text-primary);
  text-decoration: none;
  font-size: 1.125rem;
  font-weight: 500;
  border-bottom: 1px solid var(--color-border);
}

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

.mobile-lang-switcher {
  display: flex;
  gap: 0.5rem;
  padding-top: 1rem;
}

.mobile-lang-switcher a {
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text-muted);
  text-decoration: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.mobile-lang-switcher a:hover,
.mobile-lang-switcher a.active {
  color: var(--color-primary);
  border-color: var(--color-primary);
  background: rgba(37, 99, 235, 0.05);
}

/* Hero */
.hero {
  padding-top: 8rem;
  padding-bottom: 5rem;
  overflow: hidden;
}

.hero .container {
  display: flex;
  flex-direction: column;
  gap: 3rem;
}

.hero-content {
  max-width: 640px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  background: rgba(37, 99, 235, 0.1);
  border: 1px solid rgba(37, 99, 235, 0.2);
  border-radius: 9999px;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 1.5rem;
}

.hero-badge svg {
  width: 1rem;
  height: 1rem;
}

.hero h1 {
  font-size: 2.5rem;
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.025em;
  margin-bottom: 1.5rem;
  background: linear-gradient(135deg, var(--color-text-primary) 0%, var(--color-primary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-description {
  font-size: 1.125rem;
  color: var(--color-text-secondary);
  margin-bottom: 2rem;
  line-height: 1.7;
}

.hero-cta {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.875rem 1.75rem;
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  text-decoration: none;
  cursor: pointer;
  border: none;
  transition: all var(--transition-base);
}

.btn svg {
  width: 1rem;
  height: 1rem;
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-accent-gradient-start) 0%, var(--color-accent-gradient-end) 100%);
  color: white;
  box-shadow: var(--shadow-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(37, 99, 235, 0.25);
}

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

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

/* Hero Visual */
.hero-visual {
  position: relative;
  width: 100%;
  max-width: 500px;
  margin: 0 auto;
}

.hero-visual-inner {
  aspect-ratio: 4/3;
  border-radius: var(--radius-xl);
  background: linear-gradient(135deg, rgba(37, 99, 235, 0.1) 0%, rgba(124, 58, 237, 0.1) 100%);
  border: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.hero-visual-inner::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 30% 30%, rgba(37, 99, 235, 0.15) 0%, transparent 50%);
}

.hero-visual svg {
  width: 8rem;
  height: 8rem;
  color: var(--color-primary);
  opacity: 0.3;
  position: relative;
  z-index: 1;
}

/* Sections */
.section {
  padding: 5rem 0;
}

.section-header {
  text-align: center;
  max-width: 768px;
  margin: 0 auto 4rem;
}

.section-label {
  display: inline-block;
  padding: 0.375rem 1rem;
  background: rgba(37, 99, 235, 0.1);
  border-radius: 9999px;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 1rem;
}

.section-header h2 {
  font-size: 2rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 1rem;
}

.section-header p {
  font-size: 1.125rem;
  color: var(--color-text-secondary);
}

/* Features Grid */
.features-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}

.feature-card {
  padding: 2rem;
  background: var(--color-surface-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  transition: all var(--transition-base);
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(37, 99, 235, 0.2);
}

.feature-icon {
  width: 3rem;
  height: 3rem;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(37, 99, 235, 0.1);
  border-radius: var(--radius-md);
  margin-bottom: 1.25rem;
}

.feature-icon svg {
  width: 1.5rem;
  height: 1.5rem;
  color: var(--color-primary);
}

.feature-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.feature-card p {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* OpenClaw Section */
.openclaw-section {
  padding: 5rem 0;
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.openclaw-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 3rem;
  align-items: center;
}

.openclaw-visual {
  order: -1;
}

.openclaw-box {
  background: var(--color-background);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: 2rem;
  position: relative;
}

.openclaw-box-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--color-border);
}

.openclaw-box-header svg {
  width: 2rem;
  height: 2rem;
  color: var(--color-primary);
}

.openclaw-box-header h3 {
  font-size: 1.125rem;
  font-weight: 700;
}

.platforms-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.75rem;
}

.platform-badge {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-secondary);
}

.platform-badge svg {
  width: 1.25rem;
  height: 1.25rem;
  color: var(--color-primary);
}

.openclaw-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.openclaw-list li {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
}

.openclaw-list svg {
  width: 1.25rem;
  height: 1.25rem;
  color: var(--color-success);
  flex-shrink: 0;
  margin-top: 0.125rem;
}

/* API Section */
.api-section .section-header {
  margin-bottom: 3rem;
}

.code-window {
  background: #0F172A;
  border-radius: var(--radius-lg);
  overflow: hidden;
  max-width: 800px;
  margin: 0 auto;
  box-shadow: var(--shadow-lg);
}

.code-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1rem;
  background: rgba(255, 255, 255, 0.05);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.code-dots {
  display: flex;
  gap: 0.375rem;
}

.code-dot {
  width: 0.75rem;
  height: 0.75rem;
  border-radius: 50%;
}

.code-dot.red { background: #EF4444; }
.code-dot.yellow { background: #F59E0B; }
.code-dot.green { background: #10B981; }

.code-lang {
  font-size: 0.75rem;
  color: rgba(255, 255, 255, 0.5);
  font-family: var(--font-mono);
}

.code-body {
  padding: 1.5rem;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  line-height: 1.7;
  overflow-x: auto;
}

.code-body .code-comment { color: #6B7280; }
.code-body .code-keyword { color: #C084FC; }
.code-body .code-string { color: #4ADE80; }
.code-body .code-function { color: #60A5FA; }
.code-body .code-variable { color: #FBBF24; }

/* Trust Section */
.trust-section .section-header {
  margin-bottom: 3rem;
}

.trust-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
  max-width: 900px;
  margin: 0 auto;
}

.trust-item {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-text-muted);
  min-height: 80px;
}

/* Newsletter Section */
.newsletter-section {
  padding: 5rem 0;
  background: linear-gradient(135deg, var(--color-surface) 0%, rgba(37, 99, 235, 0.05) 100%);
  border-top: 1px solid var(--color-border);
}

.newsletter-form {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  max-width: 480px;
  margin: 0 auto;
}

.newsletter-form .input-group {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.input {
  padding: 0.875rem 1.25rem;
  font-size: 1rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-background);
  color: var(--color-text-primary);
  outline: none;
  transition: all var(--transition-fast);
}

.input:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.input::placeholder {
  color: var(--color-text-muted);
}

/* Contact Section */
.contact-section {
  padding: 5rem 0;
}

.contact-form {
  max-width: 640px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.form-group label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text-primary);
}

.form-group textarea {
  min-height: 150px;
  resize: vertical;
}

.submit-status {
  padding: 1rem;
  border-radius: var(--radius-md);
  font-size: 0.9375rem;
  font-weight: 500;
  text-align: center;
}

.submit-status.success {
  background: rgba(16, 185, 129, 0.1);
  color: var(--color-success);
  border: 1px solid rgba(16, 185, 129, 0.2);
}

.submit-status.error {
  background: rgba(239, 68, 68, 0.1);
  color: #EF4444;
  border: 1px solid rgba(239, 68, 68, 0.2);
}

/* Footer */
.footer {
  padding: 3rem 0;
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
}

.footer .container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1.5rem;
  list-style: none;
}

.footer-links a {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

.footer-social {
  display: flex;
  gap: 1rem;
}

.footer-social a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: var(--radius-md);
  background: var(--color-background);
  border: 1px solid var(--color-border);
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
}

.footer-social a:hover {
  color: var(--color-primary);
  border-color: var(--color-primary);
  transform: translateY(-2px);
}

.footer-social svg {
  width: 1.25rem;
  height: 1.25rem;
}

.footer-copyright {
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

/* Animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.animate-fade-in {
  opacity: 0;
}

.animate-fade-in.visible {
  animation: fadeInUp 0.6s ease forwards;
}

/* Utility */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}