/* === Design Tokens === */
:root {
  --color-bg: #fafafa;
  --color-bg-dark: #0f1419;
  --color-bg-card: #ffffff;
  --color-bg-card-dark: #1a2028;
  --color-text: #1a1a2e;
  --color-text-secondary: #555770;
  --color-text-dark: #e8e8ed;
  --color-text-dark-secondary: #a0a4b0;
  --color-primary: #2563eb;
  --color-primary-light: #3b82f6;
  --color-primary-dark: #1d4ed8;
  --color-accent: #10b981;
  --color-accent-warm: #f59e0b;
  --color-border: #e5e7eb;
  --color-border-dark: #2a3340;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-serif: 'Source Serif 4', Georgia, 'Times New Roman', serif;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.12);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --max-width: 1200px;
  --transition: 0.2s ease;
}

/* === Reset === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-font-smoothing: antialiased; }
body { font-family: var(--font-sans); color: var(--color-text); background: var(--color-bg); line-height: 1.6; }
a { text-decoration: none; color: inherit; }
img { max-width: 100%; display: block; }
button, input, select, textarea { font-family: inherit; font-size: inherit; }

/* === Layout === */
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }
.section { padding: 100px 0; }
.section-dark { background: var(--color-bg-dark); color: var(--color-text-dark); }

/* === Navigation === */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(250,250,250,0.92); backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  transition: background var(--transition);
}
.nav.scrolled { box-shadow: var(--shadow-sm); }
.nav-inner {
  max-width: var(--max-width); margin: 0 auto; padding: 0 24px;
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.nav-logo { display: flex; align-items: center; gap: 10px; color: var(--color-text); }
.nav-logo-mark { color: var(--color-primary); }
.nav-logo-text { font-weight: 700; font-size: 18px; letter-spacing: -0.3px; }
.nav-logo-suffix { font-weight: 400; color: var(--color-text-secondary); margin-left: 2px; }
.nav-links { display: flex; align-items: center; gap: 28px; }
.nav-links a {
  font-size: 14px; font-weight: 500; color: var(--color-text-secondary);
  transition: color var(--transition);
}
.nav-links a:hover { color: var(--color-text); }
.nav-cta {
  background: var(--color-primary) !important; color: #fff !important;
  padding: 8px 18px !important; border-radius: 6px;
  transition: background var(--transition) !important;
}
.nav-cta:hover { background: var(--color-primary-dark) !important; }
.nav-toggle { display: none; background: none; border: none; cursor: pointer; flex-direction: column; gap: 5px; }
.nav-toggle span { display: block; width: 22px; height: 2px; background: var(--color-text); transition: var(--transition); }

/* === Hero === */
.hero {
  position: relative; min-height: 100vh; display: flex; align-items: center;
  padding: 120px 0 80px; overflow: hidden;
  background: linear-gradient(135deg, #0f1419 0%, #162032 50%, #1a2845 100%);
  color: #fff;
}
.hero-bg { position: absolute; inset: 0; overflow: hidden; }
.hero-grid {
  position: absolute; inset: 0; opacity: 0.06;
  background-image:
    linear-gradient(rgba(255,255,255,0.3) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.3) 1px, transparent 1px);
  background-size: 60px 60px;
}
.hero-content { position: relative; max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }
.hero-label {
  font-size: 13px; font-weight: 600; text-transform: uppercase; letter-spacing: 2px;
  color: var(--color-accent); margin-bottom: 20px;
}
.hero-title {
  font-family: var(--font-serif); font-size: clamp(40px, 6vw, 72px);
  font-weight: 700; line-height: 1.1; letter-spacing: -1.5px;
  margin-bottom: 24px; max-width: 700px;
}
.hero-subtitle {
  font-size: 18px; line-height: 1.7; color: rgba(255,255,255,0.7);
  max-width: 560px; margin-bottom: 40px;
}
.hero-actions { display: flex; gap: 16px; margin-bottom: 60px; flex-wrap: wrap; }
.hero-stats {
  display: flex; gap: 48px; padding-top: 40px;
  border-top: 1px solid rgba(255,255,255,0.1);
}
.stat { display: flex; flex-direction: column; }
.stat-number { font-family: var(--font-serif); font-size: 42px; font-weight: 700; line-height: 1; color: #fff; }
.stat-label { font-size: 13px; color: rgba(255,255,255,0.5); margin-top: 6px; text-transform: uppercase; letter-spacing: 1px; }

/* === Buttons === */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 14px 28px; border-radius: 8px; font-weight: 600; font-size: 15px;
  transition: all var(--transition); cursor: pointer; border: none;
}
.btn-primary { background: var(--color-primary); color: #fff; }
.btn-primary:hover { background: var(--color-primary-dark); transform: translateY(-1px); box-shadow: 0 4px 12px rgba(37,99,235,0.3); }
.btn-secondary { background: rgba(255,255,255,0.1); color: #fff; border: 1px solid rgba(255,255,255,0.2); }
.btn-secondary:hover { background: rgba(255,255,255,0.15); }
.btn-full { width: 100%; }

/* === Section Headers === */
.section-header { text-align: center; max-width: 720px; margin: 0 auto 60px; }
.section-label {
  font-size: 13px; font-weight: 600; text-transform: uppercase;
  letter-spacing: 2px; color: var(--color-primary); margin-bottom: 12px;
}
.section-dark .section-label { color: var(--color-accent); }
.section-title {
  font-family: var(--font-serif); font-size: clamp(28px, 4vw, 40px);
  font-weight: 700; line-height: 1.2; letter-spacing: -0.5px; margin-bottom: 16px;
}
.section-subtitle { font-size: 16px; color: var(--color-text-secondary); line-height: 1.7; }
.section-dark .section-subtitle { color: var(--color-text-dark-secondary); }

/* === Mission Grid === */
.mission-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.mission-card {
  background: var(--color-bg-card); border: 1px solid var(--color-border);
  border-radius: var(--radius-md); padding: 36px; transition: box-shadow var(--transition);
}
.mission-card:hover { box-shadow: var(--shadow-md); }
.mission-icon { color: var(--color-primary); margin-bottom: 16px; }
.mission-card h3 { font-size: 20px; font-weight: 600; margin-bottom: 10px; }
.mission-card p { font-size: 15px; color: var(--color-text-secondary); line-height: 1.7; }

/* === Focus Grid === */
.focus-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.focus-card {
  background: var(--color-bg-card-dark); border: 1px solid var(--color-border-dark);
  border-radius: var(--radius-md); padding: 36px; transition: border-color var(--transition);
}
.focus-card:hover { border-color: var(--color-primary); }
.focus-primary { border-color: var(--color-primary); position: relative; }
.focus-badge {
  display: inline-block; font-size: 11px; font-weight: 600;
  text-transform: uppercase; letter-spacing: 1.5px;
  color: var(--color-primary-light); margin-bottom: 12px;
}
.focus-card h3 { font-size: 22px; font-weight: 700; margin-bottom: 12px; }
.focus-card p { font-size: 15px; color: var(--color-text-dark-secondary); line-height: 1.7; margin-bottom: 16px; }
.focus-stat { display: flex; align-items: baseline; gap: 8px; padding-top: 16px; border-top: 1px solid var(--color-border-dark); }
.focus-stat-number { font-family: var(--font-serif); font-size: 32px; font-weight: 700; color: var(--color-primary-light); }
.focus-stat-label { font-size: 14px; color: var(--color-text-dark-secondary); }

/* === Venture Portal === */
.venture-filters {
  display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; margin-bottom: 40px;
}
.filter-btn {
  padding: 8px 18px; border-radius: 20px; border: 1px solid var(--color-border);
  background: transparent; font-size: 14px; font-weight: 500;
  color: var(--color-text-secondary); cursor: pointer; transition: all var(--transition);
}
.filter-btn:hover { border-color: var(--color-primary); color: var(--color-primary); }
.filter-btn.active { background: var(--color-primary); color: #fff; border-color: var(--color-primary); }

.venture-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px;
}
.venture-card {
  background: var(--color-bg-card); border: 1px solid var(--color-border);
  border-radius: var(--radius-md); padding: 28px;
  transition: all var(--transition); position: relative; overflow: hidden;
}
.venture-card:hover {
  box-shadow: var(--shadow-md); border-color: var(--color-primary);
  transform: translateY(-2px);
}
.venture-card.hidden { display: none; }
.venture-domain {
  font-size: 11px; font-weight: 600; text-transform: uppercase; letter-spacing: 1.5px;
  color: var(--color-primary); margin-bottom: 10px;
}
.venture-name { font-size: 20px; font-weight: 700; margin-bottom: 4px; }
.venture-link {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition), color var(--transition);
}
.venture-link:hover,
.venture-link:focus-visible {
  color: var(--color-primary);
  border-bottom-color: currentColor;
  outline: none;
}
.venture-code {
  font-size: 12px; font-weight: 600; color: var(--color-text-secondary);
  margin-bottom: 10px; font-family: monospace;
}
.venture-desc { font-size: 14px; color: var(--color-text-secondary); line-height: 1.6; margin-bottom: 16px; }
.venture-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.tag {
  font-size: 11px; font-weight: 500; padding: 4px 10px;
  background: #f0f4ff; color: var(--color-primary); border-radius: 4px;
}

/* === Foundation === */
.foundation-model { margin-bottom: 60px; }
.foundation-flow {
  display: flex; align-items: stretch; gap: 0;
  background: var(--color-bg-card-dark); border-radius: var(--radius-lg);
  overflow: hidden; border: 1px solid var(--color-border-dark);
}
.flow-step { flex: 1; padding: 36px; }
.flow-step:not(:last-child) { border-right: 1px solid var(--color-border-dark); }
.flow-number {
  width: 36px; height: 36px; border-radius: 50%;
  background: var(--color-primary); color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 16px; margin-bottom: 16px;
}
.flow-step h3 { font-size: 18px; font-weight: 600; margin-bottom: 10px; }
.flow-step p { font-size: 14px; color: var(--color-text-dark-secondary); line-height: 1.6; }
.flow-arrow {
  display: flex; align-items: center; font-size: 28px;
  color: var(--color-primary-light); padding: 0 8px;
}
.grant-heading { font-size: 24px; font-weight: 700; margin-bottom: 24px; text-align: center; }
.grant-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.grant-card {
  background: var(--color-bg-card-dark); border: 1px solid var(--color-border-dark);
  border-radius: var(--radius-md); padding: 28px;
  transition: border-color var(--transition);
}
.grant-card:hover { border-color: var(--color-accent); }
.grant-amount {
  font-size: 13px; font-weight: 600; color: var(--color-accent);
  display: block; margin-bottom: 8px;
}
.grant-card h4 { font-size: 17px; font-weight: 600; margin-bottom: 8px; }
.grant-card p { font-size: 14px; color: var(--color-text-dark-secondary); line-height: 1.6; }

/* === Stanford === */
.stanford-layout { display: grid; grid-template-columns: 1.3fr 1fr; gap: 60px; align-items: start; }
.stanford-text .section-title { text-align: left; }
.stanford-text .section-label { text-align: left; }
.stanford-text > p { font-size: 16px; color: var(--color-text-secondary); line-height: 1.7; margin-bottom: 32px; }
.stanford-areas { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.stanford-area {
  padding: 20px; background: var(--color-bg-card);
  border: 1px solid var(--color-border); border-radius: var(--radius-sm);
}
.stanford-area h4 { font-size: 15px; font-weight: 600; margin-bottom: 6px; }
.stanford-area p { font-size: 13px; color: var(--color-text-secondary); line-height: 1.6; }
.stanford-visual { position: sticky; top: 100px; }
.stanford-quote {
  background: linear-gradient(135deg, #f8faff, #f0f4ff);
  border-left: 4px solid var(--color-primary);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  padding: 36px;
}
.stanford-quote blockquote {
  font-family: var(--font-serif); font-size: 18px; line-height: 1.6;
  color: var(--color-text); font-style: italic; margin-bottom: 12px;
}
.stanford-quote cite { font-size: 13px; color: var(--color-text-secondary); font-style: normal; }

/* === Audience Grid === */
.audience-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.audience-card {
  background: var(--color-bg-card-dark); border: 1px solid var(--color-border-dark);
  border-radius: var(--radius-md); padding: 32px;
  transition: border-color var(--transition);
}
.audience-card:hover { border-color: var(--color-primary); }
.audience-card h3 { font-size: 18px; font-weight: 600; margin-bottom: 10px; }
.audience-card p { font-size: 14px; color: var(--color-text-dark-secondary); line-height: 1.6; margin-bottom: 16px; }
.audience-link { font-size: 14px; font-weight: 600; color: var(--color-primary-light); }

/* === Contact === */
.contact-layout { display: grid; grid-template-columns: 1fr 1.2fr; gap: 60px; align-items: start; }
.contact-text .section-title { text-align: left; }
.contact-text .section-label { text-align: left; }
.contact-text > p { font-size: 16px; color: var(--color-text-secondary); line-height: 1.7; margin-top: 16px; }
.contact-form form { display: flex; flex-direction: column; gap: 20px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.form-group { display: flex; flex-direction: column; gap: 6px; }
.form-group label { font-size: 13px; font-weight: 600; color: var(--color-text); }
.form-group input, .form-group select, .form-group textarea {
  padding: 12px 14px; border: 1px solid var(--color-border);
  border-radius: var(--radius-sm); background: var(--color-bg-card);
  color: var(--color-text); outline: none; transition: border-color var(--transition);
}
.form-group input:focus, .form-group select:focus, .form-group textarea:focus {
  border-color: var(--color-primary); box-shadow: 0 0 0 3px rgba(37,99,235,0.1);
}
.form-group textarea { resize: vertical; }

/* === Footer === */
.footer { background: var(--color-bg-dark); color: var(--color-text-dark); padding: 60px 0 40px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
.footer-brand .nav-logo { margin-bottom: 16px; }
.footer-brand .nav-logo-mark { color: var(--color-primary-light); }
.footer-brand .nav-logo-text { color: var(--color-text-dark); }
.footer-brand .nav-logo-suffix { color: var(--color-text-dark-secondary); }
.footer-mission { font-size: 14px; color: var(--color-text-dark-secondary); line-height: 1.7; max-width: 340px; }
.footer-links { display: flex; flex-direction: column; gap: 10px; }
.footer-links h4 { font-size: 14px; font-weight: 600; margin-bottom: 4px; }
.footer-links a { font-size: 14px; color: var(--color-text-dark-secondary); transition: color var(--transition); }
.footer-links a:hover { color: var(--color-text-dark); }
.footer-bottom {
  padding-top: 24px; border-top: 1px solid var(--color-border-dark);
  text-align: center;
}
.footer-bottom p { font-size: 13px; color: var(--color-text-dark-secondary); }
.footer-legal { margin-top: 6px; font-size: 12px; }

/* === Responsive === */
@media (max-width: 1024px) {
  .venture-grid { grid-template-columns: repeat(2, 1fr); }
  .grant-grid { grid-template-columns: repeat(2, 1fr); }
  .audience-grid { grid-template-columns: repeat(2, 1fr); }
  .stanford-layout { grid-template-columns: 1fr; }
  .stanford-visual { position: static; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  .section { padding: 60px 0; }
  .nav-links { display: none; }
  .nav-links.open {
    display: flex; flex-direction: column;
    position: absolute; top: 64px; left: 0; right: 0;
    background: var(--color-bg); border-bottom: 1px solid var(--color-border);
    padding: 20px 24px; gap: 16px;
  }
  .nav-toggle { display: flex; }
  .hero { min-height: auto; padding: 120px 0 60px; }
  .hero-stats { flex-direction: column; gap: 20px; }
  .mission-grid { grid-template-columns: 1fr; }
  .focus-grid { grid-template-columns: 1fr; }
  .venture-grid { grid-template-columns: 1fr; }
  .foundation-flow { flex-direction: column; }
  .flow-step:not(:last-child) { border-right: none; border-bottom: 1px solid var(--color-border-dark); }
  .flow-arrow { display: none; }
  .grant-grid { grid-template-columns: 1fr; }
  .audience-grid { grid-template-columns: 1fr; }
  .contact-layout { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 24px; }
}

/* === Animations === */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}
.animate-in { animation: fadeUp 0.6s ease forwards; opacity: 0; }
.animate-in:nth-child(2) { animation-delay: 0.1s; }
.animate-in:nth-child(3) { animation-delay: 0.2s; }
.animate-in:nth-child(4) { animation-delay: 0.3s; }

/* ═══════════════════════════════════════════════════════
   BRAND OVERRIDES — Synapse Spark Foundation
   ═══════════════════════════════════════════════════════ */
:root {
  --brand-navy:  #0B1E3F;
  --brand-amber: #F5A623;
  --brand-cream: #F5F1E4;
  --brand-stone: #6B7A8D;
}

/* Brand amber as CTA + accent */
.btn-primary {
  background: var(--brand-amber) !important;
  color: #0B1E3F !important;
  font-weight: 700;
}
.btn-primary:hover {
  background: #e09520 !important;
  box-shadow: 0 4px 18px rgba(245,166,35,0.35) !important;
}
.section-label { color: var(--brand-amber); }
.section-dark .section-label { color: var(--brand-amber); }
.hero-label { color: var(--brand-amber); letter-spacing: 3px; }
.venture-card:hover { border-color: var(--brand-amber); }
.filter-btn.active { background: var(--brand-amber); border-color: var(--brand-amber); color: #0B1E3F; font-weight: 700; }
.filter-btn:hover { border-color: var(--brand-amber); color: var(--brand-amber); }
.focus-primary { border-color: var(--brand-amber); }
.focus-badge { color: var(--brand-amber); }
.focus-stat-number { color: var(--brand-amber); }
.mission-icon { color: var(--brand-amber); }
.nav-cta { background: var(--brand-amber) !important; color: #0B1E3F !important; font-weight: 700; }
.nav-cta:hover { background: #e09520 !important; }

/* Nav logo mark colour */
.nav-logo-mark { color: var(--brand-navy); }

/* ── Hero two-column layout ──────────────────────── */
.hero { background: linear-gradient(135deg, #050f20 0%, #0b1e3f 55%, #122850 100%); }
.hero-grid {
  background-image:
    linear-gradient(rgba(245,166,35,0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(245,166,35,0.04) 1px, transparent 1px);
  background-size: 56px 56px;
}
.hero-inner {
  position: relative;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
  width: 100%;
}
.hero-content { position: relative; max-width: none; margin: 0; padding: 0; }
.hero-visual { position: relative; display: flex; align-items: center; justify-content: flex-end; }
.hero-svg { width: 100%; max-width: 560px; opacity: 0.9; }

/* Mark in hero */
.hero-mark { display: flex; align-items: center; gap: 14px; margin-bottom: 32px; }
.hero-mark-label { font-size: 13px; font-weight: 600; letter-spacing: 2px; text-transform: uppercase; color: rgba(255,255,255,0.45); }

/* Stat number colour */
.stat-number { color: var(--brand-amber); }

/* ── Neural network animations ───────────────────── */
@keyframes node-pulse {
  0%, 100% { opacity: 0.45; }
  50%       { opacity: 1; }
}
@keyframes center-glow {
  0%, 100% { filter: drop-shadow(0 0 10px rgba(245,166,35,0.6)); }
  50%       { filter: drop-shadow(0 0 28px rgba(245,166,35,0.9)); }
}
@keyframes line-fade {
  0%, 100% { opacity: 0.08; }
  50%       { opacity: 0.3; }
}

.neural-node { animation: node-pulse 3.2s ease-in-out infinite; }
.nn-1  { animation-delay: 0s;    }
.nn-2  { animation-delay: 0.4s;  }
.nn-3  { animation-delay: 0.8s;  }
.nn-4  { animation-delay: 1.2s;  }
.nn-5  { animation-delay: 1.6s;  }
.nn-6  { animation-delay: 2.0s;  }
.nn-7  { animation-delay: 2.4s;  }
.nn-8  { animation-delay: 2.8s;  }
.nn-9  { animation-delay: 0.2s;  }
.nn-10 { animation-delay: 0.6s;  }
.nn-11 { animation-delay: 1.0s;  }
.nn-12 { animation-delay: 1.4s;  }
.nn-13 { animation-delay: 1.8s;  }
.nn-14 { animation-delay: 2.2s;  }

.neural-center { animation: center-glow 2.4s ease-in-out infinite; }
.neural-line   { animation: line-fade 4s ease-in-out infinite; }
.nl-1 { animation-delay: 0s;   }
.nl-2 { animation-delay: 0.5s; }
.nl-3 { animation-delay: 1.0s; }
.nl-4 { animation-delay: 1.5s; }
.nl-5 { animation-delay: 2.0s; }
.nl-6 { animation-delay: 2.5s; }

/* ── Responsive hero ─────────────────────────────── */
@media (max-width: 960px) {
  .hero-inner { grid-template-columns: 1fr; gap: 40px; }
  .hero-visual { display: none; }
}