/* ===== CSS Variables ===== */
:root {
  --color-bg: #FFFFFF;
  --color-bg-alt: #F9FAFB;
  --color-text: #111827;
  --color-text-muted: #6B7280;
  --color-text-light: #9CA3AF;
  --color-primary: #6366F1;
  --color-primary-dark: #4F46E5;
  --color-border: #E5E7EB;
  --color-code-bg: #1F2937;
  --color-code-text: #E5E7EB;

  --font-sans: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;

  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  --spacing-4xl: 6rem;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -1px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -2px rgba(0, 0, 0, 0.04);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.08), 0 10px 10px -5px rgba(0, 0, 0, 0.03);

  --transition: 200ms ease;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

ul {
  list-style: none;
}

button {
  border: none;
  background: none;
  cursor: pointer;
  font-family: inherit;
}

/* ===== Container ===== */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

/* ===== Header ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
  z-index: 1000;
}

.nav {
  padding: var(--spacing-md) 0;
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-weight: 600;
  font-size: 1.25rem;
  color: var(--color-text);
}

.logo img {
  border-radius: 6px;
}

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

.nav-links a {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-text-muted);
}

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

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 4px;
  padding: var(--spacing-sm);
}

.nav-toggle span {
  width: 24px;
  height: 2px;
  background-color: var(--color-text);
  border-radius: 2px;
  transition: var(--transition);
}

/* ===== Hero Section ===== */
.hero {
  padding: calc(80px + var(--spacing-4xl)) 0 var(--spacing-4xl);
  background: linear-gradient(180deg, var(--color-bg-alt) 0%, var(--color-bg) 100%);
}

.hero-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-3xl);
  align-items: center;
}

.hero-text h1 {
  font-size: clamp(2.5rem, 5vw, 3.75rem);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
  margin-bottom: var(--spacing-lg);
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-xl);
  max-width: 540px;
}

.hero-cta {
  display: flex;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: 0.75rem 1.5rem;
  font-size: 0.9375rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: all var(--transition);
}

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

.btn-primary:hover {
  background-color: #000;
  transform: translateY(-1px);
}

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

.btn-secondary:hover {
  background-color: var(--color-border);
  transform: translateY(-1px);
}

.btn-large {
  padding: 1rem 2rem;
  font-size: 1rem;
}

/* ===== Code Preview ===== */
.code-preview {
  background: var(--color-code-bg);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-xl);
}

.code-header {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-lg);
  background: rgba(0, 0, 0, 0.3);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

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

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

.filename {
  margin-left: auto;
  font-size: 0.8125rem;
  color: var(--color-text-light);
  font-family: 'SF Mono', Monaco, 'Cascadia Code', monospace;
}

.code-content {
  padding: var(--spacing-lg);
  margin: 0;
  overflow-x: auto;
}

.code-content code {
  font-family: 'SF Mono', Monaco, 'Cascadia Code', monospace;
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--color-code-text);
}

.keyword { color: #C792EA; }
.string { color: #C3E88D; }
.comment { color: #546E7A; font-style: italic; }
.class { color: #FFCB6B; }

/* ===== Features Section ===== */
.features {
  padding: var(--spacing-4xl) 0;
}

.section-header {
  text-align: center;
  max-width: 600px;
  margin: 0 auto var(--spacing-3xl);
}

.section-header h2 {
  font-size: clamp(2rem, 4vw, 2.5rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: var(--spacing-md);
}

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

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-xl);
}

.feature-card {
  padding: var(--spacing-xl);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: all var(--transition);
}

.feature-card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.feature-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-bg-alt);
  border-radius: var(--radius-sm);
  margin-bottom: var(--spacing-md);
  color: var(--color-text);
}

.feature-card h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
}

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

/* ===== Architecture Section ===== */
.architecture {
  padding: var(--spacing-4xl) 0;
  background: var(--color-bg-alt);
}

.architecture-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-3xl);
  align-items: center;
}

.arch-visual {
  display: flex;
  justify-content: center;
}

.arch-diagram {
  position: relative;
  width: 200px;
}

.arch-box {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 56px;
  background: var(--color-bg);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  font-weight: 600;
  transition: all var(--transition);
}

.arch-box.project {
  border-color: var(--color-primary);
  background: rgba(99, 102, 241, 0.05);
}

.arch-box.team {
  margin-top: var(--spacing-md);
}

.arch-box.user {
  margin-top: var(--spacing-md);
}

.arch-box:hover {
  transform: scale(1.02);
  border-color: var(--color-primary);
}

.arch-connector {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 2px;
  height: calc(100% - 28px);
  background: linear-gradient(to bottom, var(--color-primary), transparent);
  transform: translate(-50%, -50%);
  z-index: -1;
}

.architecture-text h2 {
  font-size: clamp(1.75rem, 3vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: var(--spacing-md);
}

.architecture-text > p {
  font-size: 1.125rem;
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-xl);
}

.architecture-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.architecture-list li {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.architecture-list strong {
  font-weight: 600;
  color: var(--color-text);
}

.architecture-list span {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
}

/* ===== Developer Experience Section ===== */
.developer-experience {
  padding: var(--spacing-4xl) 0;
}

.dx-comparison {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-xl);
}

.dx-code-block {
  position: relative;
}

.dx-code-block.with {
  position: relative;
}

.dx-badge {
  position: absolute;
  top: var(--spacing-md);
  right: var(--spacing-md);
  padding: var(--spacing-xs) var(--spacing-sm);
  background: rgba(16, 185, 129, 0.1);
  color: #10B981;
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
}

.dx-code-block.with .code-preview {
  border: 2px solid var(--color-primary);
}

.dx-code-block.without .code-preview {
  opacity: 0.7;
}

.dx-features {
  display: flex;
  justify-content: center;
  gap: var(--spacing-xl);
  flex-wrap: wrap;
}

.dx-feature {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 0.9375rem;
  color: var(--color-text-muted);
}

.dx-feature svg {
  color: #10B981;
}

/* ===== Tech Stack Section ===== */
.tech-stack {
  padding: var(--spacing-4xl) 0;
  background: var(--color-bg-alt);
}

.tech-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-xl);
}

.tech-category h4 {
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-md);
}

.tech-items {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
}

.tech-tag {
  padding: var(--spacing-sm) var(--spacing-md);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  transition: all var(--transition);
}

.tech-tag:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.tech-tag.soon {
  opacity: 0.6;
}

/* ===== CTA Section ===== */
.cta {
  padding: var(--spacing-4xl) 0;
  background: linear-gradient(180deg, var(--color-bg) 0%, var(--color-bg-alt) 100%);
}

.cta-content {
  text-align: center;
  max-width: 540px;
  margin: 0 auto;
}

.cta-content h2 {
  font-size: clamp(1.75rem, 3vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: var(--spacing-md);
}

.cta-content > p {
  font-size: 1.125rem;
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-xl);
}

.cta-buttons {
  display: flex;
  justify-content: center;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

/* ===== Footer ===== */
.footer {
  padding: var(--spacing-3xl) 0 var(--spacing-lg);
  background: var(--color-bg);
  border-top: 1px solid var(--color-border);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-xl);
}

.footer-col h4 {
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: var(--spacing-md);
}

.footer-col p {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  line-height: 1.6;
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.footer-col a {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
}

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

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--color-border);
}

.footer-bottom p {
  font-size: 0.875rem;
  color: var(--color-text-light);
}

.social-links {
  display: flex;
  gap: var(--spacing-md);
}

.social-links a {
  color: var(--color-text-muted);
  transition: color var(--transition);
}

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

/* ===== Mobile Responsive ===== */
@media (max-width: 968px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: 60px;
    left: 0;
    right: 0;
    flex-direction: column;
    padding: var(--spacing-lg);
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: all var(--transition);
  }

  .nav-links.active {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .nav-toggle {
    display: flex;
  }

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

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

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

  .hero-content,
  .architecture-content,
  .dx-comparison {
    grid-template-columns: 1fr;
  }

  .hero-visual {
    order: -1;
  }

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

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

  .hero {
    padding-top: calc(60px + var(--spacing-3xl));
  }
}

@media (max-width: 480px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .footer-bottom {
    flex-direction: column;
    gap: var(--spacing-md);
    text-align: center;
  }
}