/* ============================================================
   AI LONGEVITY — SHARED STYLES (v4)
   Light theme · logo-derived blue → violet → purple
   Space Grotesk / Hanken Grotesk / IBM Plex Mono
   ============================================================ */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
a { color: inherit; text-decoration: none; }
img, video { display: block; max-width: 100%; }
::selection { background: rgba(139, 92, 246, 0.20); color: var(--text-primary); }

/* Paragraph text justified site-wide (per request) */
p {
  text-align: justify;
  text-justify: inter-word;
  -webkit-hyphens: none;
  hyphens: none;
  overflow-wrap: break-word;
  word-break: normal;
}

/* ============ TYPE & COLOR TOKENS ============ */
:root {
  --font-display: 'Space Grotesk', sans-serif;
  --font-body:    'Hanken Grotesk', sans-serif;
  --font-mono:    'IBM Plex Mono', monospace;

  --bg-primary:   #f5f6fb;
  --bg-secondary: #ecedf7;
  --bg-elevated:  #ffffff;
  --bg-elevated-2:#f8f9ff;

  --text-primary:   #15172e;
  --text-secondary: #51546f;
  --text-muted:     #8a8da6;

  /* logo-derived accents */
  --accent:        #4d7cff;   /* primary azure-royal */
  --accent-bright: #6a8dff;
  --accent-blue:   #4d7cff;
  --accent-violet: #8b5cf6;
  --accent-purple: #b15cf0;
  --accent-ink:    #6a4fd8;   /* readable accent for small text on light */

  --accent-glow: rgba(77, 124, 255, 0.14);

  /* signature gradient (matches the logo sweep) */
  --grad:      linear-gradient(100deg, #3f6dff 0%, #8b5cf6 52%, #b15cf0 100%);
  --grad-rev:  linear-gradient(100deg, #b15cf0 0%, #8b5cf6 48%, #3f6dff 100%);
  --grad-line: linear-gradient(90deg, #3f6dff, #8b5cf6, #b15cf0);

  /* legacy aliases so existing markup keeps working */
  --accent-cyan: var(--accent);
  --accent-cyan-glow: var(--accent-glow);

  --border-subtle:  rgba(21, 23, 46, 0.07);
  --border-default: rgba(21, 23, 46, 0.12);
  --border-strong:  rgba(21, 23, 46, 0.20);

  --shadow-sm: 0 1px 2px rgba(21,23,46,0.04), 0 4px 14px rgba(58,68,150,0.05);
  --shadow-md: 0 2px 6px rgba(21,23,46,0.05), 0 18px 40px rgba(58,68,150,0.09);
  --shadow-lg: 0 4px 12px rgba(21,23,46,0.06), 0 30px 70px rgba(58,68,150,0.12);
}

/* ============ TYPOGRAPHY ============ */
/* Highlights render as the logo gradient. */
em, .accent-word, .hi {
  font-style: normal;
  font-weight: inherit;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent !important;
}
h1, h2, h3, h4 { font-family: var(--font-display); }
.display {
  font-family: var(--font-display);
  font-weight: 500;
  letter-spacing: -0.02em;
  line-height: 1.05;
}
.mono { font-family: var(--font-mono); font-weight: 400; font-size: 16px; }
.label {
  font-family: var(--font-mono);
  font-size: 16px;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--accent-ink);
  font-weight: 500;
}

/* ============ BACKGROUND ATMOSPHERE ============ */
.bg-atmosphere {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
}
.bg-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(21,23,46,0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(21,23,46,0.035) 1px, transparent 1px);
  background-size: 80px 80px;
  mask-image: radial-gradient(ellipse at 50% 25%, black 30%, transparent 80%);
  -webkit-mask-image: radial-gradient(ellipse at 50% 25%, black 30%, transparent 80%);
}
.bg-glow {
  position: absolute;
  width: 820px;
  height: 820px;
  border-radius: 50%;
  filter: blur(150px);
  opacity: 0.30;
}
.bg-glow.cyan   { background: #6a8dff;           top: -280px; left: -240px; }
.bg-glow.purple { background: var(--accent-purple); top: 50%;  right: -340px; opacity: 0.22; }
.bg-glow.violet {
  background: var(--accent-violet);
  width: 600px; height: 600px;
  top: 115%; left: 38%;
  opacity: 0.16;
}

/* ============ NAVIGATION ============ */
nav.site-nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  padding: 16px 48px;
  background: rgba(245, 246, 251, 0.6);
  backdrop-filter: blur(22px) saturate(1.4);
  -webkit-backdrop-filter: blur(22px) saturate(1.4);
  border-bottom: 1px solid transparent;
  transition: background .4s ease, padding .4s ease, border-color .4s ease, box-shadow .4s ease;
}
nav.site-nav.scrolled {
  background: rgba(255, 255, 255, 0.82);
  border-bottom: 1px solid var(--border-subtle);
  box-shadow: 0 6px 24px rgba(58,68,150,0.06);
  padding-top: 12px; padding-bottom: 12px;
}
.nav-inner {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 17px;
  letter-spacing: 0.01em;
  color: var(--text-primary);
}
.logo span { white-space: nowrap; }
.logo-img { height: 40px; width: auto; filter: drop-shadow(0 4px 12px rgba(124, 92, 246, 0.22)); }
.nav-links {
  display: flex;
  gap: 36px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
}
.nav-links a { transition: color 0.2s ease; position: relative; }
.nav-links a:hover, .nav-links a.active { color: var(--text-primary); }
.nav-links a.active::after {
  content: '';
  position: absolute;
  bottom: -8px; left: 0; right: 0;
  height: 2px;
  border-radius: 2px;
  background: var(--grad-line);
}
.nav-actions { display: flex; align-items: center; gap: 16px; }

/* ============ BUTTONS ============ */
.btn-primary {
  background: var(--grad);
  color: #fff;
  padding: 11px 19px;
  border-radius: 10px;
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 600;
  transition: all 0.25s ease;
  border: none;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  box-shadow: 0 6px 22px rgba(77, 124, 255, 0.26);
}
.btn-primary:hover {
  filter: brightness(1.05);
  transform: translateY(-2px);
  box-shadow: 0 12px 34px rgba(124, 92, 246, 0.34);
}
.btn-primary .arrow { transition: transform 0.2s ease; display: inline-block; }
.btn-primary:hover .arrow { transform: translateX(4px); }
.btn-ghost {
  background: var(--bg-elevated);
  color: var(--text-primary);
  padding: 11px 19px;
  border-radius: 10px;
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 600;
  border: 1px solid var(--border-default);
  cursor: pointer;
  transition: all 0.25s ease;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  box-shadow: var(--shadow-sm);
}
.btn-ghost:hover {
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}
.btn-lg { padding: 15px 24px; font-size: 15px; }

/* ============ LAYOUT ============ */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 48px;
  position: relative;
  z-index: 1;
}
section { position: relative; z-index: 1; }

/* ============ PAGE HEADER ============ */
.page-header { padding: 180px 0 80px; position: relative; }
.page-header .label { display: block; margin-bottom: 24px; }
.page-header h1 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(46px, 6vw, 80px);
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin-bottom: 24px;
}
.page-header p.intro {
  font-size: 20px;
  color: var(--text-secondary);
  max-width: 680px;
  line-height: 1.55;
}

/* ============ SECTION HEADER ============ */
.section-header { margin-bottom: 60px; max-width: 820px; }
.section-header .label { margin-bottom: 20px; display: block; }
.section-header h2 {
  font-size: clamp(34px, 4.5vw, 54px);
  line-height: 1.08;
  letter-spacing: -0.02em;
  font-family: var(--font-display);
  font-weight: 600;
}
.section-header p.subtitle {
  color: var(--text-secondary);
  font-size: 18px;
  margin-top: 24px;
  max-width: 600px;
}

/* ============ FOOTER ============ */
footer.site-footer {
  padding: 80px 0 40px;
  border-top: 1px solid var(--border-subtle);
  background: var(--bg-secondary);
  position: relative;
  z-index: 1;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 60px;
}
.footer-brand p {
  color: var(--text-secondary);
  font-size: 14px;
  margin-top: 16px;
  line-height: 1.6;
  max-width: 320px;
  text-align: left;
}
.footer-col h4 {
  font-family: var(--font-mono);
  font-size: 16px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--text-muted);
  margin-bottom: 20px;
}
.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 12px; font-size: 14px; }
.footer-col a { color: var(--text-secondary); transition: color 0.2s ease; }
.footer-col a:hover { color: var(--accent); }
.footer-bottom {
  padding-top: 32px;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 16px;
  color: var(--text-muted);
  font-family: var(--font-mono);
}
.footer-bottom-links { display: flex; gap: 24px; }

/* ============ 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; transform: scale(1); } 50% { opacity: 0.5; transform: scale(0.85); } }
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s ease-out, transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}
.reveal.visible { opacity: 1; transform: translateY(0); }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
}

/* ============ RESPONSIVE ============ */
@media (max-width: 1024px) {
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
}
@media (max-width: 768px) {
  nav.site-nav { padding: 14px 24px; }
  .nav-links { display: none; }
  .container { padding: 0 24px; }
  .page-header { padding: 120px 0 60px; }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; gap: 16px; }
}