/*
 * UBC AI in Medicine — Academic Design System
 *
 * Design decisions:
 * - Typography-driven hierarchy using Inter + Source Serif Pro
 * - UBC-aligned color palette (#002145 primary)
 * - Generous whitespace, thin borders, no heavy shadows
 * - Mobile-first responsive layout
 * - Reusable component patterns (section, card, timeline)
 */

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

/* Respect users who prefer reduced motion */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *, *::before, *::after {
    transition-duration: 0s !important;
  }
}

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  color: #1A1A1A;
  background: #FAFAFA;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: #1F4E79;
  text-decoration: none;
  transition: color 0.15s ease;
}

a:hover {
  color: #002145;
}

/* ---- Typography ---- */
h1, h2, h3, h4, h5, h6 {
  font-family: 'Inter', system-ui, sans-serif;
  font-weight: 700;
  color: #002145;
  line-height: 1.25;
}

h1 { font-size: 2.5rem; }      /* 40px */
h2 { font-size: 1.75rem; }     /* 28px */
h3 { font-size: 1.25rem; }     /* 20px */
h4 { font-size: 1.125rem; }    /* 18px */

p {
  margin-bottom: 1rem;
  color: #1A1A1A;
}

.text-muted {
  color: #6B7280;
}

.text-small {
  font-size: 0.875rem;
}

/* Accent serif for special use */
.serif {
  font-family: 'Source Serif Pro', 'Georgia', serif;
}

/* ---- Layout ---- */
.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section {
  padding: 4.5rem 0;
}

.section + .section {
  border-top: 1px solid #E5E7EB;
}

.section-label {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #6B7280;
  margin-bottom: 0.75rem;
}

.section-title {
  margin-bottom: 1rem;
}

.section-desc {
  max-width: 640px;
  color: #6B7280;
  font-size: 1.0625rem;
  line-height: 1.7;
  margin-bottom: 2.5rem;
}

/* ---- Grid ---- */
.grid {
  display: grid;
  gap: 1.5rem;
}

.grid-2 {
  grid-template-columns: 1fr;
}

.grid-3 {
  grid-template-columns: 1fr;
}

.grid-4 {
  grid-template-columns: 1fr;
}

@media (min-width: 640px) {
  .grid-2 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 960px) {
  .grid-3 { grid-template-columns: repeat(3, 1fr); }
  .grid-4 { grid-template-columns: repeat(4, 1fr); }
}

/* ---- Buttons ---- */
.btn {
  display: inline-block;
  font-family: 'Inter', system-ui, sans-serif;
  font-size: 0.9375rem;
  font-weight: 600;
  padding: 0.625rem 1.5rem;
  border-radius: 4px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 0.15s ease, border-color 0.15s ease, color 0.15s ease;
  text-align: center;
}

.btn-primary {
  background: #002145;
  color: #fff;
  border-color: #002145;
}

.btn-primary:hover {
  background: #1F4E79;
  border-color: #1F4E79;
  color: #fff;
}

.btn-outline {
  background: transparent;
  color: #002145;
  border-color: #002145;
}

.btn-outline:hover {
  background: #002145;
  color: #fff;
}

.btn-group {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.btn-group-center {
  justify-content: center;
}

/* ---- Navigation ---- */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: #fff;
  border-bottom: 1px solid #E5E7EB;
}

.site-nav .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 3.5rem;
}

.site-nav-brand {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  font-weight: 700;
  font-size: 0.9375rem;
  color: #002145;
  white-space: nowrap;
}

.site-nav-brand img {
  width: 28px;
  height: 28px;
  border-radius: 4px;
}

.site-nav-links {
  display: none;
  list-style: none;
  gap: 1.75rem;
}

.site-nav-links a {
  font-size: 0.8125rem;
  font-weight: 500;
  color: #6B7280;
  transition: color 0.15s ease;
}

.site-nav-links a:hover {
  color: #002145;
}

/* Mobile nav toggle */
.nav-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  color: #002145;
}

.nav-toggle svg {
  width: 22px;
  height: 22px;
}

/* Mobile dropdown */
.mobile-nav {
  display: none;
  background: #fff;
  border-bottom: 1px solid #E5E7EB;
  padding: 0.75rem 1.5rem 1rem;
}

.mobile-nav.is-open {
  display: block;
}

.mobile-nav a {
  display: block;
  padding: 0.5rem 0;
  font-size: 0.9375rem;
  font-weight: 500;
  color: #6B7280;
  border-bottom: 1px solid #E5E7EB;
}

.mobile-nav a:last-child {
  border-bottom: none;
}

.mobile-nav a:hover {
  color: #002145;
}

@media (min-width: 768px) {
  .site-nav-links {
    display: flex;
  }
  .nav-toggle {
    display: none;
  }
  .mobile-nav,
  .mobile-nav.is-open {
    display: none;
  }
  /* Prevent mobile nav from staying visible after viewport resize */
  .mobile-nav,
  .mobile-nav.is-open {
    display: none;
  }
}

/* ---- Hero ---- */
.hero {
  padding: 5rem 0 4rem;
  background: #fff;
  border-bottom: 1px solid #E5E7EB;
}

.hero h1 {
  font-size: 2.75rem;
  margin-bottom: 1rem;
  max-width: 600px;
}

.hero .hero-subtitle {
  font-family: 'Source Serif Pro', Georgia, serif;
  font-size: 1.1875rem;
  color: #1F4E79;
  line-height: 1.6;
  max-width: 580px;
  margin-bottom: 1.25rem;
  font-weight: 400;
}

.hero .hero-body {
  color: #6B7280;
  font-size: 1rem;
  line-height: 1.7;
  max-width: 580px;
  margin-bottom: 1.75rem;
}

.hero-meta {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
  margin-bottom: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid #E5E7EB;
}

.hero-meta-item {
  font-size: 0.8125rem;
  color: #6B7280;
}

.hero-meta-item strong {
  color: #002145;
  font-weight: 600;
}

@media (min-width: 768px) {
  .hero {
    padding: 6rem 0 5rem;
  }
  .hero h1 {
    font-size: 3rem;
  }
}

/* ---- Card (shared base) ---- */
.card {
  background: #fff;
  border: 1px solid #E5E7EB;
  border-radius: 6px;
  padding: 1.5rem;
  transition: border-color 0.15s ease;
}

.card:hover {
  border-color: #CBD5E1;
}

.card-icon {
  width: 36px;
  height: 36px;
  margin-bottom: 1rem;
  color: #1F4E79;
}

.card h3 {
  font-size: 1.0625rem;
  margin-bottom: 0.5rem;
}

.card p {
  font-size: 0.9375rem;
  color: #6B7280;
  line-height: 1.6;
  margin-bottom: 0;
}

/* ---- Project Card (Featured Work) ---- */
.project-card {
  background: #fff;
  border: 1px solid #E5E7EB;
  border-radius: 6px;
  padding: 1.75rem;
  transition: border-color 0.15s ease;
}

.project-card:hover {
  border-color: #CBD5E1;
}

.project-card-meta {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
  flex-wrap: wrap;
}

.project-card-year {
  font-size: 0.8125rem;
  font-weight: 700;
  color: #002145;
  background: #EFF6FF;
  padding: 0.125rem 0.5rem;
  border-radius: 3px;
}

.project-card-source {
  font-size: 0.8125rem;
  color: #6B7280;
  font-style: italic;
}

.project-card h3 {
  font-size: 1.0625rem;
  line-height: 1.4;
  margin-bottom: 0.625rem;
  color: #002145;
}

.project-card h3 a {
  color: inherit;
}

.project-card h3 a:hover {
  color: #1F4E79;
}

.project-card-summary {
  font-size: 0.9375rem;
  color: #6B7280;
  line-height: 1.6;
  margin-bottom: 0.75rem;
}

.project-card-insight {
  font-size: 0.875rem;
  color: #1A1A1A;
  background: #F9FAFB;
  border-left: 3px solid #CFAE70;
  padding: 0.625rem 0.875rem;
  line-height: 1.55;
  border-radius: 0 4px 4px 0;
}

.project-card-insight strong {
  color: #002145;
  font-weight: 600;
}

/* ---- Timeline ---- */
.timeline {
  position: relative;
  padding-left: 1.75rem;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.375rem;
  bottom: 0.375rem;
  width: 2px;
  background: #E5E7EB;
}

.timeline-item {
  position: relative;
  padding-bottom: 1.5rem;
}

.timeline-item:last-child {
  padding-bottom: 0;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -1.75rem;
  top: 0.375rem;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #1F4E79;
  border: 2px solid #fff;
  box-shadow: 0 0 0 2px #1F4E79;
}

.timeline-year {
  font-size: 0.8125rem;
  font-weight: 700;
  color: #002145;
  margin-bottom: 0.125rem;
}

.timeline-text {
  font-size: 0.9375rem;
  color: #6B7280;
  line-height: 1.5;
}

/* ---- Initiative Card ---- */
.initiative-card {
  background: #fff;
  border: 1px solid #E5E7EB;
  border-radius: 6px;
  padding: 1.5rem;
  transition: border-color 0.15s ease;
}

.initiative-card:hover {
  border-color: #CBD5E1;
}

.initiative-card h3 {
  font-size: 1rem;
  margin-bottom: 0.375rem;
  color: #002145;
}

.initiative-card p {
  font-size: 0.9375rem;
  color: #6B7280;
  line-height: 1.6;
  margin-bottom: 0.5rem;
}

.initiative-tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  color: #1F4E79;
  background: #EFF6FF;
  padding: 0.125rem 0.5rem;
  border-radius: 3px;
}

/* ---- Person Card ---- */
.person-card {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  padding: 1rem;
  border: 1px solid #E5E7EB;
  border-radius: 6px;
  background: #fff;
  transition: border-color 0.15s ease;
}

.person-card:hover {
  border-color: #CBD5E1;
}

.person-card-photo {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  object-fit: cover;
  flex-shrink: 0;
  background: #E5E7EB;
}

.person-card-info h4 {
  font-size: 0.9375rem;
  margin-bottom: 0.125rem;
  color: #002145;
}

.person-card-role {
  font-size: 0.8125rem;
  color: #6B7280;
  margin-bottom: 0;
}

/* ---- CTA Section ---- */
.section.cta-section {
  background: #002145;
  color: #fff;
  text-align: center;
  border-top: none;
}

.cta-section h2 {
  color: #fff;
  max-width: 540px;
  margin: 0 auto 0.75rem;
}

.cta-section p {
  color: rgba(255, 255, 255, 0.7);
  max-width: 520px;
  margin: 0 auto 2rem;
  font-size: 1rem;
}

.cta-section .btn-primary {
  background: #fff;
  color: #002145;
  border-color: #fff;
}

.cta-section .btn-primary:hover {
  background: rgba(255, 255, 255, 0.9);
  color: #002145;
}

.cta-section .btn-outline {
  color: #fff;
  border-color: rgba(255, 255, 255, 0.4);
}

.cta-section .btn-outline:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.7);
  color: #fff;
}

/* ---- Footer ---- */
.site-footer {
  padding: 2rem 0;
  border-top: 1px solid #E5E7EB;
  background: #fff;
}

.site-footer .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-text {
  font-size: 0.8125rem;
  color: #6B7280;
}

.footer-links {
  display: flex;
  gap: 1.25rem;
  list-style: none;
}

.footer-links a {
  font-size: 0.8125rem;
  color: #6B7280;
  transition: color 0.15s ease;
}

.footer-links a:hover {
  color: #002145;
}

/* ---- People Section: Team + Alumni ---- */
.people-subsection {
  margin-top: 2.5rem;
}

.people-subsection:first-child {
  margin-top: 0;
}

.people-subsection h3 {
  font-size: 1.125rem;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid #E5E7EB;
  color: #002145;
}

/* ---- Responsive adjustments ---- */
@media (max-width: 639px) {
  h1 { font-size: 2rem; }
  h2 { font-size: 1.5rem; }

  .hero {
    padding: 3rem 0;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .hero .hero-subtitle {
    font-size: 1.0625rem;
  }

  .section {
    padding: 3rem 0;
  }

  .hero-meta {
    gap: 1rem;
  }

  .project-card {
    padding: 1.25rem;
  }
}

/* Page-level modifier: reduce top padding when section is first content */
.section-flush {
  padding-top: 3rem;
}

/* ---- Utility ---- */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}