:root {
  --deep-plum: #201629;
  --violet: #49364F;
  --aqua: #3DB7AD;
  --rose: #D46B7B;
  --gold: #E8B65C;
  --mist: #F3EEF4;
  --white: #FFFFFF;
  --text: #312B37;
  --muted: #736B79;
  --border: #DDD3DF;
  
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
  --transition: all 0.3s ease;
}

/* Reset / Base */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

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

/* Typography */
h1, h2, h3, h4 {
  font-weight: 700;
  line-height: 1.2;
  color: var(--deep-plum);
  margin-bottom: 1rem;
}

p {
  margin-bottom: 1rem;
}

a {
  color: var(--aqua);
  text-decoration: none;
  transition: var(--transition);
}

a:hover, a:focus {
  color: var(--violet);
}

.text-center {
  text-align: center;
}

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

.hidden {
  display: none !important;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section-padding {
  padding: 5rem 0;
}

.bg-light {
  background-color: var(--mist);
}

.dark-section {
  background-color: var(--deep-plum);
  color: var(--mist);
}

.dark-section h2, .dark-section h3 {
  color: var(--white);
}

/* Skip link */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--aqua);
  color: var(--white);
  padding: 8px;
  z-index: 1000;
  transition: top 0.3s;
}

.skip-link:focus {
  top: 0;
}

/* Focus visible */
:focus-visible {
  outline: 3px solid var(--aqua);
  outline-offset: 2px;
}

/* Header & Nav */
.site-header {
  position: sticky;
  top: 0;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(5px);
  border-bottom: 1px solid var(--border);
  z-index: 100;
  padding: 1rem 0;
}

.header-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.logo img {
  display: block;
}

.main-nav .nav-list {
  display: flex;
  list-style: none;
  gap: 2rem;
}

.main-nav a {
  color: var(--text);
  font-weight: 500;
}

.main-nav a:hover, .main-nav a:focus {
  color: var(--aqua);
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  flex-direction: column;
  gap: 5px;
  padding: 0.5rem;
}

.hamburger {
  display: block;
  width: 25px;
  height: 3px;
  background-color: var(--deep-plum);
  transition: var(--transition);
}

/* Hero Section */
.hero {
  padding: 6rem 1.5rem;
  background: linear-gradient(135deg, var(--mist) 0%, var(--white) 100%);
  min-height: 80vh;
  display: flex;
  align-items: center;
}

.hero-container {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.eyebrow {
  text-transform: uppercase;
  font-size: 0.875rem;
  letter-spacing: 0.1em;
  color: var(--muted);
  font-weight: 700;
  margin-bottom: 1rem;
}

.hero-title {
  font-size: clamp(2.5rem, 5vw, 4rem);
  margin-bottom: 1.5rem;
}

.hero-title .highlight {
  color: var(--violet);
  background: linear-gradient(to right, var(--aqua), var(--violet));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-description {
  font-size: 1.25rem;
  color: var(--muted);
  margin-bottom: 2.5rem;
  max-width: 600px;
}

.hero-actions {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  padding: 0.875rem 2rem;
  border-radius: 4px;
  font-weight: 600;
  text-align: center;
  cursor: pointer;
}

.btn-primary {
  background-color: var(--aqua);
  color: var(--white);
  border: 2px solid var(--aqua);
}

.btn-primary:hover, .btn-primary:focus {
  background-color: var(--deep-plum);
  border-color: var(--deep-plum);
  color: var(--white);
}

.btn-secondary {
  background-color: transparent;
  color: var(--deep-plum);
  border: 2px solid var(--border);
}

.btn-secondary:hover, .btn-secondary:focus {
  border-color: var(--deep-plum);
  color: var(--deep-plum);
}

.hero-graphic {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-mark {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
  box-shadow: 0 20px 40px rgba(32, 22, 41, 0.1);
}

/* Floating Chips */
.floating-chips {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

.chip {
  position: absolute;
  background: var(--white);
  padding: 0.5rem 1rem;
  border-radius: 20px;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--violet);
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
  animation: float 6s ease-in-out infinite;
}

.chip:nth-child(1) { top: 10%; left: -5%; animation-delay: 0s; }
.chip:nth-child(2) { top: 75%; left: 10%; animation-delay: 1.5s; }
.chip:nth-child(3) { top: 20%; right: -5%; animation-delay: 3s; }
.chip:nth-child(4) { top: 80%; right: 5%; animation-delay: 4.5s; }

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

/* Principles Band */
.principles-band {
  background-color: var(--deep-plum);
  color: var(--white);
  padding: 1.5rem 0;
  overflow: hidden;
}

.band-container {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 2rem;
  flex-wrap: wrap;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
  font-weight: 500;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.separator {
  color: var(--gold);
  font-size: 1.2rem;
}

/* Fields */
.fields .section-header {
  text-align: center;
  margin-bottom: 4rem;
}

.cards-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
}

.card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 2.5rem 2rem;
  transition: var(--transition);
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 30px rgba(32, 22, 41, 0.08);
  border-color: var(--aqua);
}

.card-number {
  font-size: 2rem;
  font-weight: 700;
  color: var(--rose);
  margin-bottom: 1rem;
}

.card-title {
  font-size: 1.25rem;
  margin-bottom: 1.5rem;
  min-height: 3em;
}

.card-topics {
  list-style: none;
  color: var(--muted);
}

.card-topics li {
  margin-bottom: 0.5rem;
  position: relative;
  padding-left: 1.2rem;
}

.card-topics li::before {
  content: "•";
  position: absolute;
  left: 0;
  color: var(--gold);
}

/* Method */
.method-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
  margin-top: 3rem;
}

.step {
  border-top: 2px solid var(--aqua);
  padding-top: 1.5rem;
}

.step-title {
  color: var(--gold);
  font-size: 1.2rem;
  margin-bottom: 1rem;
}

.step-desc {
  color: var(--mist);
  opacity: 0.9;
}

/* Academics */
.profiles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2.5rem;
  margin: 4rem 0;
}

.profile-card {
  background: var(--mist);
  padding: 2rem;
  border-radius: 8px;
  text-align: center;
}

.avatar {
  width: 80px;
  height: 80px;
  background-color: var(--violet);
  color: var(--white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  font-weight: 700;
  margin: 0 auto 1.5rem;
}

.profile-name {
  font-size: 1.25rem;
  margin-bottom: 0.25rem;
}

.profile-institution {
  font-size: 0.875rem;
  color: var(--muted);
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.profile-area {
  font-size: 0.875rem;
  color: var(--aqua);
  margin-bottom: 1rem;
}

.profile-desc {
  font-size: 0.95rem;
  margin-bottom: 1.5rem;
}

.profile-links {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  font-size: 0.875rem;
  color: var(--muted);
}

.profile-links a {
  font-weight: 600;
}

.independence-note {
  max-width: 800px;
  margin: 0 auto;
  padding: 2rem;
  border-left: 4px solid var(--rose);
  background-color: var(--mist);
  font-size: 0.9rem;
  color: var(--muted);
}

.independence-note p:last-child {
  margin-bottom: 0;
}

/* Learning Library */
.search-container {
  max-width: 600px;
  margin: 2rem auto 3rem;
}

.search-box {
  width: 100%;
  padding: 1rem 1.5rem;
  font-size: 1rem;
  border: 1px solid var(--border);
  border-radius: 30px;
  font-family: inherit;
  transition: var(--transition);
}

.search-box:focus {
  outline: none;
  border-color: var(--aqua);
  box-shadow: 0 0 0 3px rgba(61, 183, 173, 0.2);
}

.library-accordion {
  max-width: 800px;
  margin: 0 auto;
}

.resource-item {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 8px;
  margin-bottom: 1rem;
  overflow: hidden;
}

.resource-item summary {
  padding: 1.5rem;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.resource-item summary::-webkit-details-marker {
  display: none;
}

.resource-item summary::after {
  content: "+";
  color: var(--aqua);
  font-size: 1.5rem;
  transition: var(--transition);
}

.resource-item[open] summary::after {
  content: "\2212"; /* minus sign */
  transform: rotate(180deg);
}

.details-content {
  padding: 0 1.5rem 1.5rem;
  color: var(--muted);
  border-top: 1px solid var(--mist);
  margin-top: 0.5rem;
  padding-top: 1rem;
}

.no-results {
  text-align: center;
  color: var(--muted);
  padding: 2rem;
}

/* About */
.about-content {
  max-width: 800px;
  font-size: 1.125rem;
}

.about-disclaimer {
  margin-top: 3rem;
  padding: 2rem;
  background-color: var(--mist);
  border-radius: 8px;
  font-size: 1rem;
}

.about-disclaimer ul {
  list-style-position: inside;
  color: var(--muted);
  margin-top: 0.5rem;
}

/* Footer */
.site-footer {
  background-color: var(--deep-plum);
  color: var(--mist);
  padding: 4rem 0 2rem;
  text-align: center;
}

.footer-logo {
  margin-bottom: 1.5rem;
}

.footer-tagline {
  max-width: 600px;
  margin: 0 auto 2rem;
  opacity: 0.8;
}

.footer-copyright {
  font-size: 0.875rem;
  opacity: 0.6;
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 2rem;
}

/* Back to Top */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 50px;
  height: 50px;
  background-color: var(--aqua);
  color: var(--white);
  border: none;
  border-radius: 50%;
  font-size: 1.5rem;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: var(--transition);
  z-index: 99;
  display: flex;
  justify-content: center;
  align-items: center;
  box-shadow: 0 4px 10px rgba(0,0,0,0.2);
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background-color: var(--violet);
  transform: translateY(-5px);
}

/* Animations Reveal */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.8s ease-out;
}

.reveal.active {
  opacity: 1;
  transform: translateY(0);
}

/* Responsive */
@media (max-width: 950px) {
  .hero-container {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 3rem;
  }
  
  .hero-description {
    margin-left: auto;
    margin-right: auto;
  }
  
  .hero-actions {
    justify-content: center;
  }
  
  .cards-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .method-steps {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .profiles-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 650px) {
  .menu-toggle {
    display: flex;
  }
  
  .main-nav {
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background: var(--white);
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
    transform: translateY(-150%);
    transition: transform 0.3s ease;
    z-index: -1;
    opacity: 0;
    visibility: hidden;
  }
  
  .main-nav.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }
  
  .main-nav .nav-list {
    flex-direction: column;
    padding: 2rem;
    gap: 1.5rem;
    text-align: center;
  }
  
  .cards-grid {
    grid-template-columns: 1fr;
  }
  
  .method-steps {
    grid-template-columns: 1fr;
  }
  
  .profiles-grid {
    grid-template-columns: 1fr;
  }
  
  .band-container {
    flex-direction: column;
    gap: 0.5rem;
  }
  
  .separator {
    display: none;
  }
}