/* 
  Theme: Modern AI Researcher / Lab Notes
  Author: Gemini CLI
*/

:root {
  /* Colors - Light Mode (Ink on Paper) */
  --bg-color: #f8f9fa;
  --text-color: #212529;
  --text-muted: #6c757d;
  --accent-color: #0d6efd; /* Electric Blue/Neon-ish */
  --accent-color-rgb: 13, 110, 253;
  --secondary-color: #495057;
  --card-bg: #ffffff;
  --border-color: #dee2e6;
  --grid-color: rgba(0, 0, 0, 0.03);
  
  /* Typography */
  --font-sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  
  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --spacing-lg: 4rem;
  
  /* Transitions */
  --transition-speed: 0.3s;
  
  /* Layout */
  --max-width: 900px;
  --nav-height: 70px;
}

[data-theme="dark"] {
  /* Colors - Dark Mode (Dark Lab Notebook) */
  --bg-color: #1a1e21; /* Deep Slate */
  --text-color: #e9ecef;
  --text-muted: #adb5bd;
  --accent-color: #61a5fa; /* Softer Blue Glow */
  --accent-color-rgb: 97, 165, 250;
  --secondary-color: #ced4da;
  --card-bg: #212529;
  --border-color: #343a40;
  --grid-color: rgba(255, 255, 255, 0.03);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-color);
  color: var(--text-color);
  line-height: 1.6;
  transition: background-color var(--transition-speed), color var(--transition-speed);
  background-image: linear-gradient(var(--grid-color) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-color) 1px, transparent 1px);
  background-size: 20px 20px;
}

/* Typography Overrides */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-mono);
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
  letter-spacing: -0.02em;
}

a {
  color: var(--accent-color);
  text-decoration: none;
  transition: opacity 0.2s ease;
}

a:hover {
  opacity: 0.8;
  text-decoration: underline;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-sm);
}

/* Skip Link */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--accent-color);
  color: white;
  padding: 8px;
  z-index: 1000;
  transition: top 0.2s;
}

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

/* Navigation */
.main-nav {
  position: sticky;
  top: 0;
  background-color: rgba(var(--bg-color), 0.9); /* Requires RGB handling in real implementations usually, simplifying here or using opacity on element */
  background-color: var(--bg-color); /* Fallback */
  border-bottom: 1px solid var(--border-color);
  z-index: 100;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  backdrop-filter: blur(10px);
}

/* Hex trick for opacity if needed, but keeping simple */
[data-theme="dark"] .main-nav {
  background-color: rgba(26, 30, 33, 0.9);
}
[data-theme="light"] .main-nav {
  background-color: rgba(248, 249, 250, 0.9);
}


.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-sm);
}

.logo {
  font-family: var(--font-mono);
  font-weight: bold;
  font-size: 1.2rem;
  color: var(--text-color);
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: var(--spacing-sm);
  list-style: none;
}

.nav-links a {
  color: var(--text-muted);
  font-size: 0.9rem;
  font-weight: 500;
  padding: 0.5rem;
  border-radius: 4px;
}

.nav-links a:hover, .nav-links a.active {
  color: var(--accent-color);
  background-color: rgba(13, 110, 253, 0.1);
  text-decoration: none;
}

.theme-toggle {
  background-color: transparent;
  border: 1px solid transparent;
  color: var(--text-muted);
  padding: 0.5rem 1rem;
  border-radius: 99px; /* Pill shape */
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 500;
  margin-left: var(--spacing-sm);
  display: flex; /* Use flexbox */
  align-items: center;
  justify-content: center;
  gap: 0.5rem; /* Space between icon and text */
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: none;
}

.theme-toggle:hover {
  background-color: rgba(var(--accent-color-rgb), 0.1);
  color: var(--accent-color);
  border-color: rgba(var(--accent-color-rgb), 0.2);
  transform: translateY(-1px);
}

.theme-icon {
    font-size: 1.1em; /* Slightly larger icon */
    line-height: 1; /* Align icon better */
}

.theme-text {
    /* No specific styling needed for text beyond parent */
}


/* Icon Visibility Logic */
.theme-icon-sun, .theme-icon-moon {
  display: none;
}

[data-theme="light"] .theme-icon-moon {
  display: block; /* Show Moon in light mode (to switch to dark) */
}

[data-theme="dark"] .theme-icon-sun {
  display: block; /* Show Sun in dark mode (to switch to light) */
}

/* Mobile Nav */
.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  color: var(--text-color);
  font-size: 1.5rem;
  cursor: pointer;
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    width: 100%;
    background-color: var(--bg-color);
    flex-direction: column;
    padding: var(--spacing-sm);
    border-bottom: 1px solid var(--border-color);
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
  }

  .nav-links.open {
    display: flex;
  }

  .mobile-menu-btn {
    display: block;
  }
}

/* Hero Section */
.hero {
  min-height: 50vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  position: relative;
  overflow: hidden;
  padding-top: var(--spacing-md);
  padding-bottom: var(--spacing-md);
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 600px;
}

.hero h1 {
  font-size: 3rem;
  margin-bottom: 0.5rem;
  color: var(--text-color);
}

.hero h2 {
  font-size: 1.5rem;
  color: var(--text-muted);
  font-family: var(--font-sans);
  font-weight: 400;
  margin-bottom: 0.5rem;
}

.hero-affiliation {
  font-size: 1.1rem;
  color: var(--accent-color);
  font-family: var(--font-mono);
  margin-bottom: var(--spacing-md);
}

.hero-tagline {
  font-size: 1.2rem;
  max-width: 500px;
}

/* Neural/Constellation Background */
.neural-bg {
  position: absolute;
  top: 0;
  right: -10%;
  width: 60%;
  height: 100%;
  z-index: 1;
  opacity: 0.1;
  pointer-events: none;
}

[data-theme="dark"] .neural-bg {
  opacity: 0.05;
}

/* Sections */
section {
  padding: var(--spacing-lg) 0;
  border-bottom: 1px solid var(--border-color);
}

section:last-child {
  border-bottom: none;
}

.section-title {
  font-size: 2rem;
  margin-bottom: var(--spacing-md);
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 40px;
  height: 3px;
  background-color: var(--accent-color);
}

/* Scroll Animation Class */
.fade-in-section {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
  will-change: opacity, visibility;
}

.fade-in-section.is-visible {
  opacity: 1;
  transform: none;
}

/* About Grid */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: var(--spacing-md);
  align-items: start;
}

.profile-img-container {
  width: 100%;
  aspect-ratio: 1 / 1;
  background-color: var(--border-color);
  border-radius: 8px;
  overflow: hidden;
  position: relative;
}

.profile-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: filter 0.3s;
  /* Grayscale until hover for that "lab" feel, maybe? Let's keep color but muted */
  filter: grayscale(20%);
}

.profile-img:hover {
  filter: grayscale(0%);
}

.bio-text p {
  margin-bottom: var(--spacing-sm);
}

.research-list {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-sm);
  margin-top: var(--spacing-md);
}

.research-item {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  padding: var(--spacing-sm);
  border-radius: 4px;
  border-left: 3px solid var(--accent-color);
  font-family: var(--font-mono);
  font-size: 0.9rem;
}

@media (max-width: 768px) {
  .about-grid {
    grid-template-columns: 1fr;
  }
  
  .profile-img-container {
    max-width: 300px;
    margin: 0 auto;
  }
}

/* Publications */
.pub-controls {
  margin-bottom: var(--spacing-md);
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  align-items: center;
}

.search-box {
  padding: 0.5rem;
  border: 1px solid var(--border-color);
  border-radius: 4px;
  background: var(--bg-color);
  color: var(--text-color);
  font-family: var(--font-sans);
  min-width: 250px;
}

.year-filter {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.year-chip {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  padding: 0.3rem 0.8rem;
  border-radius: 20px;
  font-size: 0.85rem;
  cursor: pointer;
  transition: all 0.2s;
}

.year-chip:hover, .year-chip.active {
  background: var(--accent-color);
  color: white;
  border-color: var(--accent-color);
}

.pub-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.pub-card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  padding: var(--spacing-sm);
  border-radius: 4px;
  transition: transform 0.2s, box-shadow 0.2s;
}

.pub-card:hover {
  transform: translateX(5px);
  box-shadow: 0 4px 6px rgba(0,0,0,0.05);
  border-left-color: var(--accent-color);
}

.pub-title {
  font-weight: 700;
  font-size: 1.1rem;
  margin-bottom: 0.25rem;
}

.pub-authors {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 0.25rem;
}

.pub-meta {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--secondary-color);
  display: flex;
  gap: var(--spacing-sm);
  align-items: center;
}

.pub-year {
  background: var(--grid-color);
  padding: 2px 6px;
  border-radius: 4px;
}

/* Contact */
.contact-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-md);
  margin-top: var(--spacing-md);
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.1rem;
}

.btn {
  display: inline-block;
  padding: 0.6rem 1.2rem;
  background-color: var(--accent-color);
  color: white;
  border-radius: 4px;
  font-weight: 600;
  text-decoration: none;
  transition: background-color 0.2s;
  border: none;
  cursor: pointer;
}

.btn:hover {
  background-color: var(--secondary-color); /* Just a different state */
  color: white;
  text-decoration: none;
  opacity: 1;
}

.btn-outline {
  background-color: transparent;
  border: 2px solid var(--accent-color);
  color: var(--accent-color);
}

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

/* Footer */
footer {
  text-align: center;
  padding: var(--spacing-md) 0;
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-top: var(--spacing-lg);
  border-top: 1px solid var(--border-color);
}

/* Back to Top */
#back-to-top {
  position: fixed;
  bottom: 20px;
  right: 20px;
  background-color: var(--accent-color);
  color: white;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s, visibility 0.3s;
  border: none;
  z-index: 99;
}

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

/* Icons generic styling */
.icon {
  width: 20px;
  height: 20px;
  fill: currentColor;
}