@import url('https://fonts.googleapis.com/css2?family=Spectral:ital,wght@0,300;0,400;0,600;1,400&family=Inter:wght@300;400;500;600&display=swap');

:root {
  /* The "Academic Organic" Light Palette */
  --color-bg-primary: #FDFCF8; /* Alabaster White */
  --color-bg-secondary: #F6F4ED; /* Soft Oatmeal */
  
  --color-text-main: #23292E; /* Deep Charcoal */
  --color-text-muted: #6B7280; /* Muted Storm Grey */
  
  --color-accent-primary: #8CA18C; /* Muted Sage Green */
  --color-accent-secondary: #C37A61; /* Warm Terra Cotta / Copper */

  --border-subtle: #EFECE1;
  --border-hover: rgba(195, 122, 97, 0.5);
  
  --shadow-soft: 0 12px 35px rgba(35, 41, 46, 0.04);
  --shadow-glow: 0 8px 25px rgba(140, 161, 140, 0.15);

  --font-main: 'Inter', sans-serif;
  --font-serif: 'Spectral', serif;
  
  --transition-smooth: all 0.4s cubic-bezier(0.25, 0.8, 0.25, 1);
  --spacing-section: 8rem;

  /* Skeleton Colors (Light) */
  --skeleton-bg: #EFECE1;
  --skeleton-highlight: #FDFCF8;
}

[data-theme="dark"] {
  /* The "Muted Noir" Dark Palette */
  --color-bg-primary: #1A1D21; /* Deep Space Charcoal */
  --color-bg-secondary: #24282D; /* Slate Ink */
  
  --color-text-main: #FDFCF8; /* Alabaster text */
  --color-text-muted: #94A3B8; /* Soft Slate Blue/Grey */
  
  --color-accent-primary: #A4BBA4; /* Lighter Sage for Contrast */
  --color-accent-secondary: #D98C72; /* Brighter Copper */

  --border-subtle: #2D3339;
  --border-hover: rgba(217, 140, 114, 0.6);
  
  --shadow-soft: 0 12px 35px rgba(0, 0, 0, 0.3);
  --shadow-glow: 0 8px 25px rgba(164, 187, 164, 0.1);

  --skeleton-bg: #2D3339;
  --skeleton-highlight: #3D444B;
}

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

/* Base Fade-in Transition */
body {
  font-family: var(--font-main);
  background-color: var(--color-bg-primary);
  color: var(--color-text-main);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background-color 0.5s ease, color 0.5s ease;
  opacity: 0;
  animation: fadeInContent 0.8s ease forwards;
}

@keyframes fadeInContent {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-serif);
  font-weight: 600;
  color: var(--color-text-main);
  line-height: 1.25;
}

.text-gradient {
  background: linear-gradient(135deg, var(--color-accent-primary), var(--color-accent-secondary));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

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

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

.container {
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 2rem;
}

section {
  padding: var(--spacing-section) 0;
}

.section-title {
  text-align: center;
  font-size: 2.8rem;
  margin-bottom: 1rem;
  letter-spacing: -0.02em;
}

.section-subtitle {
  text-align: center;
  color: var(--color-text-muted);
  margin-bottom: 5rem;
  font-size: 1.15rem;
  font-weight: 400;
  font-family: var(--font-serif);
  font-style: italic;
}

/* Header & Nav */
header {
  position: fixed;
  top: 0;
  width: 100%;
  padding: 1.2rem 0;
  background: var(--color-bg-primary);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  z-index: 1000;
  border-bottom: 1px solid var(--border-subtle);
  transition: background-color 0.5s ease;
}

.header-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-family: var(--font-serif);
  font-size: 1.6rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--color-text-main);
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
  align-items: center;
}

.nav-links a {
  font-size: 0.85rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  width: 0;
  height: 2px;
  bottom: -4px;
  left: 0;
  background: var(--color-accent-secondary);
  transition: var(--transition-smooth);
}

.nav-links a:hover::after,
.nav-links a.active::after,
.nav-links a[aria-current="page"]::after {
  width: 100%;
}

.nav-links a:hover,
.nav-links a.active,
.nav-links a[aria-current="page"] {
  color: var(--color-text-main);
}

/* Theme Toggle Button */
.theme-toggle {
  background: transparent;
  border: 1px solid var(--border-subtle);
  color: var(--color-text-main);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition-smooth);
}

.theme-toggle:hover {
  border-color: var(--color-accent-secondary);
  color: var(--color-accent-secondary);
  transform: rotate(15deg);
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 0.9rem 2rem;
  background: transparent;
  border: 1px solid var(--border-subtle);
  color: var(--color-text-main);
  border-radius: 6px; 
  cursor: pointer;
  font-weight: 500;
  transition: var(--transition-smooth);
}

.btn:hover {
  border-color: var(--color-accent-secondary);
  background: rgba(195, 122, 97, 0.04);
  transform: translateY(-2px);
}

.btn-primary {
  background: var(--color-accent-primary);
  color: #fff;
  border: none;
}

.btn-primary:hover {
  background: var(--color-accent-secondary);
  color: #fff;
  box-shadow: var(--shadow-glow);
  transform: translateY(-2px);
}

/* Hero Section */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 80px;
  position: relative;
  overflow: hidden;
}

#particles-js {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1;
}

.hero-content {
  max-width: 800px;
  position: relative;
  z-index: 2;
  pointer-events: none;
}

.hero-content a.btn {
  pointer-events: all;
}

.hero h1 {
  font-size: 4.5rem;
  margin-bottom: 1.5rem;
  letter-spacing: -0.02em;
}

.hero p {
  font-size: 1.25rem;
  color: var(--color-text-muted);
  margin-bottom: 2.5rem;
  max-width: 650px;
}

/* Card Grids */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 2rem;
}

.card {
  background: var(--color-bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  padding: 2.5rem;
  transition: var(--transition-smooth);
  display: flex;
  flex-direction: column;
  position: relative;
  box-shadow: var(--shadow-soft);
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--color-accent-primary), var(--color-accent-secondary));
  opacity: 0;
  transition: var(--transition-smooth);
  border-top-left-radius: 8px;
  border-top-right-radius: 8px;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 20px 40px rgba(0,0,0,0.1);
}

.card:hover::before {
  opacity: 1;
}

.card h3 {
  font-size: 1.6rem;
  margin-bottom: 1rem;
}

.card p {
  color: var(--color-text-muted);
  margin-bottom: 2rem;
  flex-grow: 1;
  font-size: 0.95rem;
}

/* Skeleton Loading Effect */
.skeleton {
  background: var(--skeleton-bg);
  background: linear-gradient(90deg, var(--skeleton-bg) 25%, var(--skeleton-highlight) 50%, var(--skeleton-bg) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite linear;
  border-radius: 4px;
}

@keyframes shimmer {
  to { background-position: -200% 0; }
}

.skeleton-card {
  min-height: 250px;
  border-radius: 8px;
}

/* Medical Custom Cards */
.medical-card {
  background: var(--color-bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  padding: 2.5rem;
  display: flex;
  gap: 2rem;
  align-items: flex-start;
  transition: var(--transition-smooth);
  box-shadow: var(--shadow-soft);
}

.medical-card:hover {
  transform: translateX(5px);
  border-color: var(--border-hover);
}

/* Research News Timeline */
.news-list {
  display: flex;
  flex-direction: column;
  gap: 2rem;
  max-width: 800px;
  margin: 0 auto;
  border-left: 2px solid var(--border-subtle);
  padding-left: 2rem;
}

.news-item {
  position: relative;
  padding: 1.5rem 2rem;
  background: var(--color-bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  box-shadow: var(--shadow-soft);
  transition: var(--transition-smooth);
}

.news-item:hover {
  transform: translateX(5px);
  border-color: var(--border-hover);
}

.news-item::before {
  content: '';
  position: absolute;
  top: 2rem;
  left: -2.65rem;
  width: 14px;
  height: 14px;
  background: var(--color-bg-primary);
  border: 3px solid var(--color-accent-primary);
  border-radius: 50%;
  box-shadow: 0 0 0 4px var(--color-bg-primary);
  z-index: 10;
}

.news-date {
  font-family: var(--font-serif);
  font-weight: 600;
  font-style: italic;
  color: var(--color-accent-secondary);
  font-size: 0.95rem;
  margin-bottom: 0.5rem;
  display: block;
}

/* Footer */
footer {
  margin-top: auto;
  border-top: 1px solid var(--border-subtle);
  padding: 3rem 0;
  text-align: center;
  background: var(--color-bg-secondary);
  transition: background-color 0.5s ease;
}

.social-links {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.social-links a {
  width: 45px;
  height: 45px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: var(--color-bg-primary);
  border: 1px solid var(--border-subtle);
  color: var(--color-text-main);
  transition: var(--transition-smooth);
  box-shadow: var(--shadow-soft);
}

.social-links a:hover {
  border-color: var(--color-accent-secondary);
  color: var(--color-accent-secondary);
  transform: translateY(-3px);
}

/* Journey Timeline (for Profile) */
.timeline {
  position: relative;
  max-width: 800px;
  margin: 4rem auto 0;
  padding: 2rem 0;
}

.timeline::after {
  content: '';
  position: absolute;
  width: 2px;
  background-color: var(--border-subtle);
  top: 0;
  bottom: 0;
  left: 50%;
  margin-left: -1px;
}

.timeline-item {
  padding: 10px 40px;
  position: relative;
  background-color: inherit;
  width: 50%;
}

.timeline-item::after {
  content: '';
  position: absolute;
  width: 20px;
  height: 20px;
  right: -10px;
  background-color: var(--color-bg-primary);
  border: 3px solid var(--color-accent-secondary);
  top: 15px;
  border-radius: 50%;
  z-index: 1;
}

.left { left: 0; }
.right { left: 50%; }

.right::after { left: -10px; }

.timeline-content {
  padding: 1.5rem;
  background-color: var(--color-bg-secondary);
  position: relative;
  border-radius: 6px;
  border: 1px solid var(--border-subtle);
}

/* Utility Classes */
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
}

.gallery-img {
  width: 100%;
  aspect-ratio: 1;
  object-fit: cover;
  border-radius: 8px;
  transition: var(--transition-smooth);
  cursor: pointer;
  filter: grayscale(10%);
}

.gallery-img:hover {
  transform: scale(1.02);
  filter: grayscale(0%);
}

/* Modals */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0, 0, 0, 0.6);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 2000;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.4s ease;
  backdrop-filter: blur(8px);
}

.modal-overlay.active {
  opacity: 1;
  pointer-events: all;
}

.modal-content {
  background: var(--color-bg-primary);
  padding: 3rem;
  border-radius: 12px;
  max-width: 650px;
  width: 90%;
  box-shadow: 0 25px 50px rgba(0,0,0,0.3);
  position: relative;
  transform: translateY(20px);
  transition: all 0.4s ease;
}

.modal-overlay.active .modal-content {
  transform: translateY(0);
}

.modal-close {
  background: transparent;
  border: none;
  cursor: pointer;
  color: var(--color-text-muted);
  transition: var(--transition-smooth);
}

.modal-close:hover {
  color: var(--color-accent-secondary);
  transform: rotate(90deg);
}

/* Forms */
.form-group input, .form-group textarea {
  width: 100%;
  padding: 1rem;
  border-radius: 6px;
  background: var(--color-bg-secondary);
  border: 1px solid var(--border-subtle);
  color: var(--color-text-main);
  font-family: inherit;
  transition: var(--transition-smooth);
}

.form-group input:focus, .form-group textarea:focus {
  outline: none;
  border-color: var(--color-accent-primary);
  box-shadow: 0 0 0 3px rgba(140, 161, 140, 0.1);
}

/* Scrollbar */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--color-bg-primary); }
::-webkit-scrollbar-thumb { background: #D1D5DB; border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--color-accent-primary); }

/* Mobile */
@media (max-width: 768px) {
  .hero h1 { font-size: 3rem; }
  .nav-links {
    position: fixed;
    top: 70px;
    left: 0;
    width: 100%;
    background: var(--color-bg-primary);
    flex-direction: column;
    padding: 2rem;
    transform: translateY(-150%);
    transition: transform 0.4s ease;
    border-bottom: 1px solid var(--border-subtle);
  }
  .nav-links.nav-open { transform: translateY(0); }
  .mobile-toggle { display: block; background: none; border: none; font-size: 1.5rem; color: var(--color-text-main); }
  .timeline::after { left: 31px; }
  .timeline-item { width: 100%; padding-left: 70px; padding-right: 25px; }
  .timeline-item::after { left: 21px; }
  .right { left: 0; }
}