/* 
  Modern Startup Design System
  Inspired by Stripe, Linear, Vercel
*/

:root {
  /* Colors */
  --bg-color: #FAFAFA;
  --surface-color: #FFFFFF;
  --text-primary: #111827;
  --text-secondary: #6B7280;
  --text-tertiary: #9CA3AF;
  
  --primary-color: #4F46E5; /* Indigo 600 */
  --primary-hover: #4338CA; /* Indigo 700 */
  --primary-light: #EEF2FF; /* Indigo 50 */
  
  --border-color: #E5E7EB;
  --border-hover: #D1D5DB;
  
  --success-color: #10B981;
  --success-bg: #ECFDF5;
  --warning-color: #F59E0B;
  --warning-bg: #FFFBEB;
  --info-color: #3B82F6;
  --info-bg: #EFF6FF;

  /* Typography */
  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  /* Spacing */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-2xl: 48px;
  --spacing-3xl: 64px;
  --spacing-4xl: 96px;

  /* Radius */
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.05), 0 4px 6px -2px rgba(0, 0, 0, 0.025);
  --shadow-hover: 0 20px 25px -5px rgba(0, 0, 0, 0.05), 0 10px 10px -5px rgba(0, 0, 0, 0.02);
  
  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 250ms cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-color);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

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

ul {
  list-style: none;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.2;
  color: var(--text-primary);
}

h1 { font-size: 3.75rem; }
h2 { font-size: 2.5rem; }
h3 { font-size: 1.75rem; }
h4 { font-size: 1.25rem; }

.text-gradient {
  background: linear-gradient(135deg, var(--text-primary) 0%, #6B7280 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.text-accent-gradient {
  background: linear-gradient(135deg, var(--primary-color) 0%, #818CF8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

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

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

.section {
  padding: var(--spacing-4xl) 0;
}

.grid {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-lg);
}

.grid-cols-2 > * { width: calc(50% - var(--spacing-lg)/2); }
.grid-cols-3 > * { width: calc(33.333% - var(--spacing-lg)*2/3); }

@media (max-width: 768px) {
  .grid-cols-2 > *, .grid-cols-3 > * {
    width: 100%;
  }
}

/* Components */

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  font-weight: 600;
  font-size: 1rem;
  border-radius: var(--radius-full);
  transition: all var(--transition-fast);
  cursor: pointer;
  border: 1px solid transparent;
}

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

.btn-primary:hover {
  background-color: black;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

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

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

.btn-ghost {
  color: var(--text-secondary);
  padding: 8px 16px;
}

.btn-ghost:hover {
  color: var(--text-primary);
  background-color: var(--spacing-xs);
}

/* Header */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(250, 250, 250, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(0,0,0,0.05);
  padding: var(--spacing-md) 0;
}

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

.logo {
  font-weight: 800;
  font-size: 1.25rem;
  letter-spacing: -0.05em;
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo-icon {
  width: 24px;
  height: 24px;
  background: var(--text-primary);
  border-radius: 6px;
}

.nav-links {
  display: flex;
  gap: var(--spacing-lg);
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
}

.nav-link:hover, .nav-link.active {
  color: var(--text-primary);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
}

@media (max-width: 768px) {
  .nav-links { display: none; }
  .mobile-menu-btn { display: block; }
}

/* Cards */
.card {
  background-color: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  transition: all var(--transition-normal);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
  border-color: var(--primary-light);
}

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

/* Badges */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.badge-live { background: var(--success-bg); color: var(--success-color); }
.badge-beta { background: var(--info-bg); color: var(--info-color); }
.badge-soon { background: var(--warning-bg); color: var(--warning-color); }

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

.footer-content {
  display: flex;
  justify-content: space-between;
  gap: var(--spacing-2xl);
  flex-wrap: wrap;
}

.footer-col h4 {
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-md);
}

.footer-col ul li {
  margin-bottom: var(--spacing-sm);
}

.footer-col ul li a {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

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

/* Animations using ScrollReveal logic later, but base classes here */
.fade-up {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

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