/* ============================================
   Predictive Biology — Design System
   Aesthetic: Scientific precision meets 
   organic warmth. Clean, authoritative, 
   with subtle life-science visual cues.
   ============================================ */

:root {
  /* Colors — Deep teal/slate palette with warm accents */
  --color-ink: #1a2632;
  --color-ink-light: #3d4f5f;
  --color-ink-muted: #6b7c8a;
  --color-paper: #fafbfc;
  --color-paper-warm: #f5f3f0;
  --color-accent: #0d7377;
  --color-accent-light: #14919b;
  --color-accent-glow: rgba(13, 115, 119, 0.08);
  --color-highlight: #e8f4f4;
  --color-border: #e2e6ea;
  --color-border-light: #f0f2f4;
  
  /* Typography */
  --font-display: 'Instrument Serif', Georgia, serif;
  --font-body: 'DM Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  
  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 2rem;
  --space-lg: 4rem;
  --space-xl: 6rem;
  --space-2xl: 10rem;
  
  /* Layout */
  --max-width: 1200px;
  --max-width-narrow: 800px;
  
  /* Transitions */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --duration: 0.4s;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  font-size: 1.0625rem;
  line-height: 1.7;
  color: var(--color-ink);
  background: var(--color-paper);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

body.nav-open {
  overflow: hidden;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 400;
  line-height: 1.2;
  color: var(--color-ink);
}

h1 {
  font-size: clamp(2.5rem, 6vw, 4rem);
  letter-spacing: -0.02em;
}

h2 {
  font-size: clamp(1.875rem, 4vw, 2.5rem);
  letter-spacing: -0.01em;
}

h3 {
  font-size: clamp(1.375rem, 2.5vw, 1.75rem);
}

h4 {
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}

p {
  margin-bottom: 1.5em;
}

p:last-child {
  margin-bottom: 0;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--duration) var(--ease-out);
}

a:hover {
  color: var(--color-accent-light);
}

strong {
  font-weight: 600;
}

/* ============================================
   Header
   ============================================ */

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(250, 251, 252, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border-light);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--color-ink);
}

.logo-mark {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  background: var(--color-accent);
  color: white;
  font-family: var(--font-display);
  font-size: 1rem;
  border-radius: 8px;
}

.logo-text {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 400;
}

.main-nav {
  display: flex;
  gap: 2.5rem;
}

.nav-link {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-ink-light);
  text-decoration: none;
  position: relative;
  padding: 0.25rem 0;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-accent);
  transition: width var(--duration) var(--ease-out);
}

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

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-ink);
  transition: all 0.3s ease;
}

/* Mobile nav */
@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
    z-index: 1001;
  }
  
  .nav-toggle[aria-expanded="true"] span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
  }
  
  .nav-toggle[aria-expanded="true"] span:nth-child(2) {
    opacity: 0;
  }
  
  .nav-toggle[aria-expanded="true"] span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
  }
  
  .main-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--color-paper);
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 2rem;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease;
  }
  
  .main-nav.open {
    opacity: 1;
    visibility: visible;
  }
  
  .main-nav .nav-link {
    font-size: 1.5rem;
  }
}

/* ============================================
   Main Content
   ============================================ */

main {
  padding-top: 80px;
}

/* Section Layouts */
.section {
  padding: var(--space-xl) var(--space-md);
}

.section-narrow {
  max-width: var(--max-width-narrow);
  margin: 0 auto;
}

.section-wide {
  max-width: var(--max-width);
  margin: 0 auto;
}

/* ============================================
   Hero Section
   ============================================ */

.hero {
  min-height: calc(100vh - 80px);
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  background: linear-gradient(165deg, var(--color-paper) 0%, var(--color-highlight) 100%);
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  right: 0;
  width: 50%;
  height: 100%;
  background: url('/images/09695d_f053c64a93a7466b82265006a1ee31b3~mv2_d_2524_1897_s_2.jpg') center/cover no-repeat;
  opacity: 0.15;
  mask-image: linear-gradient(to left, rgba(0,0,0,0.6) 0%, transparent 100%);
  -webkit-mask-image: linear-gradient(to left, rgba(0,0,0,0.6) 0%, transparent 100%);
  pointer-events: none;
}

/* Subtle accent overlay */
.hero::after {
  content: '';
  position: absolute;
  top: 0;
  right: 0;
  width: 50%;
  height: 100%;
  background: radial-gradient(ellipse 80% 60% at 80% 40%, rgba(13, 115, 119, 0.04) 0%, transparent 60%);
  pointer-events: none;
}

.hero-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-lg) var(--space-md);
  position: relative;
  z-index: 1;
}

.hero-content {
  max-width: 720px;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: 1.5rem;
  opacity: 0;
  animation: fadeUp 0.8s var(--ease-out) 0.2s forwards;
}

.hero-eyebrow::before {
  content: '';
  width: 32px;
  height: 2px;
  background: var(--color-accent);
}

.hero h1 {
  margin-bottom: 1.5rem;
  opacity: 0;
  animation: fadeUp 0.8s var(--ease-out) 0.4s forwards;
}

.hero h1 em {
  font-style: italic;
  color: var(--color-accent);
}

.hero-lead {
  font-size: 1.25rem;
  line-height: 1.8;
  color: var(--color-ink-light);
  max-width: 600px;
  opacity: 0;
  animation: fadeUp 0.8s var(--ease-out) 0.6s forwards;
}

.hero-cta {
  display: flex;
  gap: 1rem;
  margin-top: 2.5rem;
  opacity: 0;
  animation: fadeUp 0.8s var(--ease-out) 0.8s forwards;
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 1rem 2rem;
  font-family: var(--font-body);
  font-size: 0.9375rem;
  font-weight: 600;
  text-decoration: none;
  border-radius: 8px;
  transition: all var(--duration) var(--ease-out);
  cursor: pointer;
  border: none;
}

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

.btn-primary:hover {
  background: var(--color-accent-light);
  color: white;
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(13, 115, 119, 0.25);
}

.btn-secondary {
  background: transparent;
  color: var(--color-ink);
  border: 1.5px solid var(--color-border);
}

.btn-secondary:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* ============================================
   Content Sections
   ============================================ */

.content-section {
  padding: var(--space-xl) var(--space-md);
}

.content-section.alt-bg {
  background: var(--color-paper-warm);
}

.section-header {
  max-width: var(--max-width);
  margin: 0 auto var(--space-lg);
  text-align: center;
}

.section-header h2 {
  margin-bottom: 1rem;
}

.section-header p {
  font-size: 1.125rem;
  color: var(--color-ink-light);
  max-width: 600px;
  margin: 0 auto;
}

/* Feature Cards */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
  max-width: var(--max-width);
  margin: 0 auto;
}

.feature-card {
  background: white;
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 2.5rem;
  transition: all var(--duration) var(--ease-out);
}

a.feature-card {
  display: block;
  text-decoration: none;
  color: inherit;
  cursor: pointer;
}

a.feature-card h3 {
  color: var(--color-ink);
}

.feature-card:hover {
  border-color: var(--color-accent);
  box-shadow: 0 12px 40px rgba(13, 115, 119, 0.08);
  transform: translateY(-4px);
}

.feature-icon {
  width: 48px;
  height: 48px;
  background: var(--color-accent-glow);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.5rem;
  color: var(--color-accent);
}

.feature-card h3 {
  margin-bottom: 1rem;
  font-size: 1.375rem;
}

.feature-card p {
  color: var(--color-ink-light);
  font-size: 1rem;
}

/* Research Areas */
.research-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--color-border);
  max-width: var(--max-width);
  margin: 0 auto;
  border-radius: 12px;
  overflow: hidden;
}

@media (max-width: 900px) {
  .research-grid {
    grid-template-columns: 1fr;
  }
}

.research-item {
  background: white;
  padding: 3rem;
  position: relative;
}

.research-item h3 {
  font-size: 1.5rem;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.research-item h3::before {
  content: '';
  width: 8px;
  height: 8px;
  background: var(--color-accent);
  border-radius: 50%;
}

.research-item p {
  color: var(--color-ink-light);
  font-size: 1rem;
}

/* Technology Stack */
.tech-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.tech-tag {
  padding: 0.5rem 1rem;
  background: var(--color-highlight);
  border-radius: 100px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-accent);
}

/* ============================================
   Page Content (inner pages)
   ============================================ */

.page-header {
  padding: var(--space-xl) var(--space-md) var(--space-lg);
  background: linear-gradient(170deg, var(--color-paper) 0%, var(--color-highlight) 100%);
  text-align: center;
}

.page-header h1 {
  max-width: var(--max-width-narrow);
  margin: 0 auto;
}

.page-header .lead {
  font-size: 1.25rem;
  color: var(--color-ink-light);
  max-width: 600px;
  margin: 1.5rem auto 0;
}

.page-content {
  max-width: var(--max-width-narrow);
  margin: 0 auto;
  padding: var(--space-lg) var(--space-md);
}

.page-content h2 {
  margin-top: 3rem;
  margin-bottom: 1.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--color-border);
}

.page-content h2:first-child {
  margin-top: 0;
  padding-top: 0;
  border-top: none;
}

.page-content h3 {
  margin-top: 2rem;
  margin-bottom: 1rem;
}

.page-content ul, 
.page-content ol {
  margin-bottom: 1.5rem;
  padding-left: 1.5rem;
}

.page-content li {
  margin-bottom: 0.5rem;
}

.page-content img {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
  margin: 2rem 0;
}

.page-content figure {
  margin: 2rem 0;
}

.page-content figcaption {
  font-size: 0.875rem;
  color: var(--color-ink-muted);
  text-align: center;
  margin-top: 0.75rem;
}

/* Callout boxes */
.callout {
  background: var(--color-accent-glow);
  border-left: 3px solid var(--color-accent);
  padding: 1.5rem 2rem;
  margin: 2rem 0;
  border-radius: 0 8px 8px 0;
}

.callout h4 {
  color: var(--color-accent);
  margin-bottom: 0.5rem;
}

/* Two-column content */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: start;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-lg) var(--space-md);
}

@media (max-width: 900px) {
  .two-col {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
}

.two-col-text h2 {
  margin-bottom: 1.5rem;
}

.two-col-visual {
  position: relative;
}

.two-col-visual img {
  width: 100%;
  border-radius: 12px;
  box-shadow: 0 20px 60px rgba(26, 38, 50, 0.1);
}

/* Image grid for organoids */
.image-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin: 2rem 0;
}

.image-grid img {
  width: 100%;
  border-radius: 8px;
}

@media (max-width: 600px) {
  .image-grid {
    grid-template-columns: 1fr;
  }
}

/* ============================================
   Contact Page
   ============================================ */

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 4rem;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-lg) var(--space-md);
}

@media (max-width: 900px) {
  .contact-grid {
    grid-template-columns: 1fr;
  }
}

.contact-info h2 {
  margin-bottom: 1.5rem;
}

.contact-info address {
  font-style: normal;
  font-size: 1.125rem;
  line-height: 1.8;
  color: var(--color-ink-light);
  margin-bottom: 2rem;
}

.contact-info a {
  display: inline-block;
  font-size: 1.125rem;
  font-weight: 500;
}

.contact-form {
  background: white;
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 3rem;
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-group label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--color-ink);
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 1rem;
  font-family: var(--font-body);
  font-size: 1rem;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-glow);
}

.form-group textarea {
  min-height: 150px;
  resize: vertical;
}

/* ============================================
   Footer
   ============================================ */

.site-footer {
  background: var(--color-ink);
  color: rgba(255, 255, 255, 0.7);
  padding: var(--space-xl) var(--space-md) var(--space-md);
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 4rem;
  padding-bottom: var(--space-lg);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

@media (max-width: 768px) {
  .footer-inner {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
}

.footer-brand .footer-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.footer-brand .logo-mark {
  background: var(--color-accent);
  color: white;
  width: 2.25rem;
  height: 2.25rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-display);
  font-size: 0.875rem;
  border-radius: 6px;
}

.footer-brand .logo-text {
  font-family: var(--font-display);
  font-size: 1.125rem;
  color: white;
}

.footer-tagline {
  font-size: 0.9375rem;
  line-height: 1.7;
  max-width: 320px;
}

.footer-contact h4,
.footer-nav h4 {
  color: white;
  margin-bottom: 1rem;
}

.footer-contact address {
  font-style: normal;
  font-size: 0.9375rem;
  line-height: 1.7;
  margin-bottom: 0.75rem;
}

.footer-contact a {
  color: var(--color-accent-light);
}

.footer-contact a:hover {
  color: white;
}

.footer-nav nav {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.footer-nav a {
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.9375rem;
}

.footer-nav a:hover {
  color: white;
}

.footer-bottom {
  max-width: var(--max-width);
  margin: 0 auto;
  padding-top: var(--space-md);
  text-align: center;
}

.footer-bottom p {
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.5);
}

/* ============================================
   Utilities
   ============================================ */

.text-center { text-align: center; }
.text-accent { color: var(--color-accent); }
.mt-lg { margin-top: var(--space-lg); }
.mb-lg { margin-bottom: var(--space-lg); }

/* Responsive */
@media (max-width: 600px) {
  :root {
    --space-lg: 3rem;
    --space-xl: 4rem;
  }
  
  .header-inner {
    padding: 1rem;
  }
  
  .hero-cta {
    flex-direction: column;
  }
  
  .features-grid {
    grid-template-columns: 1fr;
  }
  
  .contact-form {
    padding: 2rem;
  }
}