/* ════════════════════════════════════════════════════════════════════
   STYLE.CSS — Design Tokens, Reset, Base, Typography, Utilities, Animations
   Design System: AI Revenue Activation (Inter / Vercel-inspired)
   ════════════════════════════════════════════════════════════════════ */

/* ═══ DESIGN TOKENS ═══ */
:root {
  /* Base Colors */
  --bg-white: #ffffff;
  --bg-warm: #faf9f8;
  --bg-dark: #0a0a0b;
  --bg-card: #ffffff;
  --bg-elevated: #f7f7f8;

  /* Text Colors */
  --text-primary: #171717;
  --text-secondary: #5a5a5a;
  --text-tertiary: #8a8a8a;
  --text-inverse: #ffffff;

  /* Accent Colors */
  --accent: #f57c00;
  --accent-hover: #e07000;
  --accent-subtle: rgba(245, 124, 0, 0.08);
  --accent-light: #fff4e5;

  /* Semantic Colors */
  --blue: #2563eb;
  --blue-subtle: rgba(37, 99, 235, 0.08);
  --green: #16a34a;
  --green-subtle: rgba(22, 163, 74, 0.08);
  --purple: #7c3aed;
  --purple-subtle: rgba(124, 58, 237, 0.08);

  /* Borders */
  --border: rgba(0, 0, 0, 0.08);
  --border-light: rgba(0, 0, 0, 0.04);
  --border-card: rgba(0, 0, 0, 0.06);

  /* Radii */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;

  /* Shadows */
  --shadow-sm: 0px 0px 0px 1px rgba(0, 0, 0, 0.06);
  --shadow-md: 0px 0px 0px 1px rgba(0, 0, 0, 0.08), 0px 2px 4px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0px 0px 0px 1px rgba(0, 0, 0, 0.08), 0px 4px 16px rgba(0, 0, 0, 0.06);
  --shadow-xl: 0px 0px 0px 1px rgba(0, 0, 0, 0.08), 0px 8px 32px rgba(0, 0, 0, 0.08);

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

  /* Layout */
  --max-w: 1200px;
  --header-h: 72px;
  --section-py: 100px;
}

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

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

body {
  font-family: var(--font);
  background: var(--bg-white);
  color: var(--text-primary);
  overflow-x: hidden;
  line-height: 1.6;
}

a { text-decoration: none; color: inherit; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }
img { max-width: 100%; display: block; }
ul, ol { list-style: none; }
h1, h2, h3, h4, h5, h6 { font-weight: inherit; font-size: inherit; }

/* ═══ BASE TYPOGRAPHY ═══ */
.section-label {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-tertiary);
  margin-bottom: 12px;
}

.section-title {
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.15;
  color: var(--text-primary);
  margin-bottom: 16px;
}

.section-title .highlight { color: var(--accent); }

.section-sub {
  font-size: clamp(15px, 2vw, 18px);
  color: var(--text-secondary);
  max-width: 640px;
  line-height: 1.7;
  font-weight: 400;
  margin: 0 auto;
}

/* Section dark overrides */
.section-dark .section-title { color: var(--text-inverse); }
.section-dark .section-sub { color: rgba(255, 255, 255, 0.6); }
.section-dark .section-label { color: rgba(255, 255, 255, 0.4); }

/* ═══ UTILITIES ═══ */
.container { max-width: var(--max-w); margin: 0 auto; padding: 0 24px; }

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  background: var(--accent-subtle);
  color: var(--accent);
  border-radius: 100px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.tag-blue { background: var(--blue-subtle); color: var(--blue); }
.tag-green { background: var(--green-subtle); color: var(--green); }
.tag-purple { background: var(--purple-subtle); color: var(--purple); }

.icon { display: inline-block; vertical-align: middle; flex-shrink: 0; }

.page-wrapper { min-height: 100vh; display: flex; flex-direction: column; }
.page-content { flex: 1; padding-top: var(--header-h); }

section { padding: var(--section-py) 0; }

.section-dark {
  background: var(--bg-dark);
  color: var(--text-inverse);
}

.section-warm { background: var(--bg-warm); }

.section-header {
  text-align: center;
  margin-bottom: 60px;
}

.section-inner { max-width: 1280px; margin: 0 auto; }

/* Section color helpers */
.bg-white { background: var(--bg-white); }
.bg-light { background: var(--bg-warm); }
.bg-dark { background: var(--bg-dark); color: var(--text-inverse); }
.bg-deep { background: var(--bg-dark); color: var(--text-inverse); }

/* ═══ PRINT ═══ */
@media print {
  .no-print { display: none !important; }
  body { background: white !important; color: black !important; width: 210mm; height: 297mm; }
  section { page-break-inside: avoid; border-bottom: 1px solid #eee; margin-bottom: 2rem; padding-bottom: 2rem; }
  .print-full-width { width: 100% !important; max-width: 100% !important; }
  button { display: none !important; }
  .hero-diagram, .hero-visual { display: none !important; }
  .grid { display: block !important; }
  .card { border: 1px solid #ddd !important; margin-bottom: 1rem !important; }
}

/* ═══ ANIMATIONS ═══ */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-4px); }
}

@keyframes float {
  0% { transform: translateY(0px); }
  50% { transform: translateY(-20px); }
  100% { transform: translateY(0px); }
}

@keyframes scaleUp {
  from { transform: scale(0.9); opacity: 0; }
  to { transform: scale(1); opacity: 1; }
}

@keyframes cardIn {
  from { opacity: 0; transform: translateY(18px); }
  to { opacity: 1; transform: none; }
}

/* Animation utility classes */
.fade-up { animation: fadeUp 0.6s ease both; }
.fade-in { animation: fadeIn 0.6s ease both; }

.stagger-1 { animation: fadeUp 0.6s 0.1s both; }
.stagger-2 { animation: fadeUp 0.6s 0.2s both; }
.stagger-3 { animation: fadeUp 0.6s 0.3s both; }
.stagger-4 { animation: fadeUp 0.6s 0.4s both; }

.animate-float { animation: float 6s ease-in-out infinite; }
.animate-scale-up { animation: scaleUp 0.4s cubic-bezier(0.16, 1, 0.3, 1) forwards; }
.animate-fade-in { animation: fadeIn 0.3s ease-out forwards; }
.animation-delay-500 { animation-delay: 0.5s; }
.animation-delay-2000 { animation-delay: 2s; }

/* Blog card staggered delays */
.blog-card:nth-child(1) { animation-delay: 0.02s; }
.blog-card:nth-child(2) { animation-delay: 0.08s; }
.blog-card:nth-child(3) { animation-delay: 0.14s; }
.blog-card:nth-child(4) { animation-delay: 0.20s; }
.blog-card:nth-child(5) { animation-delay: 0.26s; }
.blog-card:nth-child(n+6) { animation-delay: 0.30s; }

/* ═══ REDUCED MOTION ═══ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  .blog-card { opacity: 1; animation: none; }
  .blog-card:hover, .blog-grid:not(.filtered) article:first-child:hover { transform: none; }
  .chip:hover { transform: none; }
}