/* main.css - GramionGroup Linear/Stripe Style Design System */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

:root {
  /* Linear / Stripe Light Colors */
  --bg-primary: #FAFAFA;
  --bg-surface: #FFFFFF;
  --bg-surface-hover: #F4F4F5;
  --bg-surface-alt: #F3F4F6;
  
  --border-color: #E4E4E7;
  --border-light: #F4F4F5;
  
  /* Primary Actions (Black or very dark grey in Linear) */
  --primary-btn: #18181B;
  --primary-btn-hover: #27272A;
  
  /* Accent colors */
  --accent-blue: #3B82F6; /* Stripe-ish vibrant blue */
  --accent-blue-light: #EFF6FF;
  --accent-rose: #E11D48;
  --accent-emerald: #10B981;
  --interactive-blue: #2563EB;
  
  /* Text Colors */
  --text-main: #09090B;
  --text-muted: #52525B;
  --text-lighter: #71717A;
  --text-inverse: #FFFFFF;
  
  /* Typography */
  --font-primary: 'Inter', system-ui, -apple-system, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  
  /* Geometry */
  --radius-base: 12px;
  --radius-btn: 8px;
  --radius-badge: 9999px;
  --grid-base: 4px;
  
  /* Spacing */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-6: 24px;
  --space-8: 32px;
  --space-12: 48px;
  --space-16: 64px;
  --space-24: 96px;
  --space-32: 128px;
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 300ms cubic-bezier(0.4, 0, 0.2, 1);
  
  /* Layout */
  --container-width: 1200px;
}

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

html, body {
  height: 100%;
  background-color: var(--bg-primary);
  color: var(--text-main);
  font-family: var(--font-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  display: flex;
  flex-direction: column;
}

main {
  flex: 1;
}

p {
  margin-bottom: var(--space-4);
  color: var(--text-muted);
}
p:last-child {
  margin-bottom: 0;
}

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

a {
  color: var(--interactive-blue);
  text-decoration: none;
  transition: color var(--transition-fast);
}
a:hover {
  color: var(--primary-btn);
}

ul, ol {
  list-style: none;
}

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

/* Typography Scale */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.15;
  margin-bottom: var(--space-4);
  letter-spacing: -0.03em;
  color: var(--text-main);
}

.hero-title {
  font-size: clamp(48px, 6vw, 84px);
  margin-bottom: var(--space-6);
  letter-spacing: -0.04em;
  background: linear-gradient(180deg, #09090B 0%, #52525B 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.section-title {
  font-size: clamp(32px, 4vw, 48px);
  margin-bottom: var(--space-4);
  letter-spacing: -0.03em;
}

.subtitle {
  font-size: 1.25rem;
  color: var(--text-muted);
  margin-bottom: var(--space-8);
  max-width: 700px;
  line-height: 1.6;
}

.body-large { font-size: 1.125rem; }
.body-base { font-size: 1rem; }
.body-small { font-size: 0.875rem; }

.mono {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

/* Layout Utilities */
.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.section {
  padding: var(--space-12) 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  border-bottom: 1px solid var(--border-color);
}
.section:nth-child(even) {
  background-color: var(--bg-surface-alt);
}

.grid { display: grid; gap: var(--space-8); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.flex { display: flex; }
.flex-col { display: flex; flex-direction: column; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.gap-2 { gap: var(--space-2); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }
.gap-8 { gap: var(--space-8); }

.text-center { text-align: center; }
.text-accent { color: var(--accent-blue); }
.text-primary { color: var(--primary-btn); }
.text-muted { color: var(--text-muted); }

/* Header - Linear Style */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(250, 250, 250, 0.7);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid transparent;
  transition: all var(--transition-normal);
  padding: var(--space-4) 0;
}

.site-header.scrolled {
  border-bottom: 1px solid var(--border-color);
  background-color: rgba(255, 255, 255, 0.9);
}

.logo-link {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text-main);
  letter-spacing: -0.02em;
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.logo-node {
  width: 24px;
  height: 24px;
  border-radius: 6px;
  background: linear-gradient(135deg, var(--accent-blue) 0%, #1D4ED8 100%);
  position: relative;
  box-shadow: 0 2px 4px rgba(37, 99, 235, 0.2);
}
.logo-node::after {
  content: '';
  position: absolute;
  top: 6px; left: 6px; right: 6px; bottom: 6px;
  background-color: white;
  border-radius: 2px;
}

/* Nav */
.desktop-nav ul {
  display: flex;
  gap: var(--space-8);
}
.desktop-nav a {
  color: var(--text-muted);
  font-size: 0.875rem;
  font-weight: 500;
  transition: color var(--transition-fast);
}
.desktop-nav a:hover, .desktop-nav a.active {
  color: var(--text-main);
}

/* Footer */
.site-footer {
  background-color: var(--bg-surface);
  border-top: 1px solid var(--border-color);
  padding: var(--space-24) 0 var(--space-8);
  margin-top: auto;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr 1fr;
  gap: var(--space-8);
  margin-bottom: var(--space-16);
}

.footer-col h4 {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: var(--space-6);
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

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

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

.footer-bottom {
  padding-top: var(--space-8);
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.875rem;
  color: var(--text-lighter);
}