/* ==============================================================================
   LAUNCHFLOW DESIGN SYSTEM & BASE STYLES
   Modern, ultra-fast, zero-dependency CSS with Dark/Light theme switching
   ============================================================================== */

:root {
  /* Color Palette Variables (fallback values; dynamically updated by site.config.js) */
  --color-primary: #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-secondary: #0f172a;
  --color-accent: #10b981;
  --color-danger: #ef4444;
  --color-warning: #f59e0b;
  
  /* Light Theme */
  --bg-body: #ffffff;
  --bg-surface: #f8fafc;
  --bg-surface-elevated: #ffffff;
  --text-primary: #0f172a;
  --text-muted: #64748b;
  --border-color: #e2e8f0;
  --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --card-shadow-hover: 0 20px 25px -5px rgba(0, 0, 0, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
  --nav-bg: rgba(255, 255, 255, 0.85);

  /* Typography */
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  
  /* Layout Sizing */
  --max-width: 1200px;
  --header-height: 72px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
}

/* Dark Theme Overrides */
[data-theme="dark"] {
  --bg-body: #0b0f19;
  --bg-surface: #131b2e;
  --bg-surface-elevated: #1a233b;
  --text-primary: #f8fafc;
  --text-muted: #94a3b8;
  --border-color: #1e293b;
  --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
  --card-shadow-hover: 0 20px 25px -5px rgba(0, 0, 0, 0.5);
  --nav-bg: rgba(11, 15, 25, 0.85);
}

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

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

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background-color: var(--bg-body);
  color: var(--text-primary);
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

main {
  flex: 1 0 auto;
}

/* Typography Defaults */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-primary);
  line-height: 1.25;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

h1 { font-size: clamp(2.25rem, 4vw + 1rem, 3.5rem); letter-spacing: -0.03em; }
h2 { font-size: clamp(1.75rem, 2.5vw + 1rem, 2.5rem); letter-spacing: -0.02em; }
h3 { font-size: 1.35rem; }
h4 { font-size: 1.15rem; }

p {
  color: var(--text-muted);
  margin-bottom: 1.25rem;
  font-size: 1.05rem;
}

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

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

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

/* Container & Layout */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

.section {
  padding: 5rem 0;
}

.section-sm {
  padding: 3rem 0;
}

.section-header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto 3.5rem auto;
}

.section-tag {
  display: inline-block;
  padding: 0.35rem 0.85rem;
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  background-color: rgba(37, 99, 235, 0.1);
  color: var(--color-primary);
  border-radius: var(--radius-full);
  margin-bottom: 1rem;
}

/* Responsive Grid Helpers */
.grid {
  display: grid;
  gap: 2rem;
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

@media (max-width: 992px) {
  .grid-3, .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }
  .section {
    padding: 3.5rem 0;
  }
}

/* Flexbox Helpers */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }
.gap-3 { gap: 1.5rem; }

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-muted { color: var(--text-muted); }
.font-bold { font-weight: 700; }
.w-full { width: 100%; }
.mt-2 { margin-top: 1rem; }
.mt-4 { margin-top: 2rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-4 { margin-bottom: 2rem; }