@import url('https://fonts.googleapis.com/css2?family=Cormorant+Garamond:ital,wght@0,400;0,500;0,600;0,700;1,400;1,500&family=Inter:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

/* ==========================================
   THEME DESIGN VARIABLES
   ========================================== */
:root {
  /* Typography */
  --font-serif: 'Cormorant Garamond', Georgia, serif;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  /* Layout Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --spacing-lg: 3.5rem;
  --spacing-xl: 5.5rem;
  --spacing-xxl: 8rem;

  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  
  /* Borders & Radius */
  --border-radius: 4px;
}

/* Light Theme (Default Editorial Paper Vibe) */
[data-theme="light"], :root:not([data-theme="dark"]) {
  --color-bg: #f9f8f6;          /* Editorial off-white */
  --color-bg-secondary: #f2f1ed;/* Muted stone grey */
  --color-text-primary: #1a1a18;/* Deep ink charcoal */
  --color-text-secondary: #52514d; /* Muted reading grey */
  --color-text-muted: #85837d;
  --color-border: #e2dfd7;      /* Clean subtle paper edge */
  --color-border-strong: #1a1a18;
  --color-accent: #802c1a;       /* Sophisticated brick red */
  --color-accent-hover: #b8422a;
  --color-nav-bg: rgba(249, 248, 246, 0.9);
  --color-accent-light: rgba(128, 44, 26, 0.05);
}

/* Dark Theme (High-Contrast Editorial Night Vibe) */
[data-theme="dark"] {
  --color-bg: #121211;          /* Ink black */
  --color-bg-secondary: #1a1a19;/* Warm slate charcoal */
  --color-text-primary: #f2f1ed;/* Soft paper white */
  --color-text-secondary: #a8a7a1;/* Muted silver grey */
  --color-text-muted: #706f6a;
  --color-border: #2a2a29;      /* Dark paper edge */
  --color-border-strong: #f2f1ed;
  --color-accent: #e27d60;       /* Soft terracotta red */
  --color-accent-hover: #f08d71;
  --color-nav-bg: rgba(18, 18, 17, 0.9);
  --color-accent-light: rgba(226, 125, 96, 0.08);
}

/* ==========================================
   RESET & SYSTEM BASICS
   ========================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--color-bg);
  color: var(--color-text-primary);
  line-height: 1.625;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-serif);
  font-weight: 600;
  line-height: 1.15;
  color: var(--color-text-primary);
  letter-spacing: -0.01em;
}

p, li {
  font-size: 1.05rem;
  font-weight: 400;
  color: var(--color-text-secondary);
}

a {
  color: var(--color-text-primary);
  text-decoration: none;
  border-bottom: 1px solid var(--color-border);
  transition: all var(--transition-fast);
}

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

ul {
  list-style: none;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
  filter: grayscale(15%);
  transition: filter var(--transition-normal);
}

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

/* ==========================================
   LAYOUT & UTILITIES
   ========================================== */
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.section {
  padding: var(--spacing-xl) 0;
  border-bottom: 1px solid var(--color-border);
}

.section:last-of-type {
  border-bottom: none;
}

.section-title {
  font-size: clamp(2rem, 4.5vw, 3.25rem);
  font-weight: 500;
  font-style: italic;
  margin-bottom: var(--spacing-lg);
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.section-title::after {
  content: '';
  flex-grow: 1;
  height: 1px;
  background-color: var(--color-border);
}

/* Editorial Card Base */
.glass-card {
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  padding: var(--spacing-md);
  transition: border-color var(--transition-fast), background-color var(--transition-fast);
}

.glass-card:hover {
  border-color: var(--color-text-muted);
}

/* Button & Link Elements */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.65rem 1.25rem;
  border-radius: var(--border-radius);
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
  border-bottom: none;
}

.btn-primary {
  background-color: var(--color-border-strong);
  color: var(--color-bg);
}

.btn-primary:hover {
  background-color: var(--color-accent);
  color: #fff;
  transform: translateY(-1px);
}

.btn-secondary {
  background-color: transparent;
  color: var(--color-text-primary);
  border: 1px solid var(--color-border);
}

.btn-secondary:hover {
  border-color: var(--color-text-primary);
  background-color: rgba(0, 0, 0, 0.02);
  transform: translateY(-1px);
}

[data-theme="dark"] .btn-secondary:hover {
  background-color: rgba(255, 255, 255, 0.02);
}

.arrow-link {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 1.1rem;
  color: var(--color-accent);
  border-bottom: none;
  font-weight: 500;
}

.arrow-link:hover {
  color: var(--color-accent-hover);
}

.arrow-link::after {
  content: ' →';
  transition: transform var(--transition-fast);
}

.arrow-link:hover::after {
  transform: translateX(3px);
}

/* ==========================================
   NAVIGATION BAR
   ========================================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background-color: var(--color-nav-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  transition: background-color var(--transition-normal), border-bottom-color var(--transition-normal);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 4.5rem;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.logo {
  font-family: var(--font-serif);
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--color-text-primary);
  border-bottom: none;
  letter-spacing: -0.01em;
}

.logo-dot {
  display: inline-block;
  width: 6px;
  height: 6px;
  background-color: var(--color-accent);
  border-radius: 50%;
  margin-left: 2px;
}

.nav-menu {
  display: flex;
  gap: 1.5rem;
  align-items: center;
}

.nav-link {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  border-bottom: none;
  position: relative;
  padding: 0.25rem 0;
}

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

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 100%;
  height: 1px;
  background-color: var(--color-text-primary);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform var(--transition-fast);
}

.nav-link:hover::after, .nav-link.active::after {
  transform: scaleX(1);
  transform-origin: left;
}

/* Theme Toggle */
.theme-toggle {
  background: transparent;
  border: 1px solid var(--color-border);
  color: var(--color-text-primary);
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.theme-toggle:hover {
  background-color: var(--color-bg-secondary);
  border-color: var(--color-text-muted);
}

.theme-toggle svg {
  width: 1rem;
  height: 1rem;
  fill: currentColor;
}

[data-theme="dark"] .sun-icon { display: block; }
[data-theme="dark"] .moon-icon { display: none; }
[data-theme="light"] .sun-icon { display: none; }
[data-theme="light"] .moon-icon { display: block; }

.mobile-menu-btn {
  display: none;
  background: transparent;
  border: none;
  color: var(--color-text-primary);
  cursor: pointer;
}

/* ==========================================
   HERO SECTION
   ========================================== */
.hero {
  min-height: auto;
  display: flex;
  align-items: center;
  padding-top: 8.5rem;
  padding-bottom: 4.5rem;
  border-bottom: 1px solid var(--color-border);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.25fr 0.75fr;
  gap: var(--spacing-lg);
  align-items: center;
}

.hero-content h5 {
  font-family: var(--font-mono);
  color: var(--color-accent);
  font-weight: 500;
  font-size: 0.85rem;
  letter-spacing: 0.1em;
  margin-bottom: var(--spacing-xs);
  text-transform: uppercase;
}

.hero-content h1 {
  font-size: clamp(2.5rem, 5.5vw, 4.25rem);
  font-weight: 400;
  line-height: 1.1;
  margin-bottom: var(--spacing-sm);
}

.hero-content h1 span {
  font-style: italic;
  font-family: var(--font-serif);
  font-weight: 600;
}

.hero-tagline {
  font-size: clamp(1.1rem, 2vw, 1.25rem);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-md);
  max-width: 600px;
  line-height: 1.6;
}

.hero-tagline strong {
  font-weight: 600;
  color: var(--color-text-primary);
}

.hero-buttons {
  display: flex;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-md);
}

.hero-image-wrapper {
  justify-self: center;
}

.profile-card {
  width: 280px;
  height: 320px;
  border-radius: var(--border-radius);
  overflow: hidden;
  border: 1px solid var(--color-border);
}

.profile-card img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ==========================================
   ABOUT ME SECTION
   ========================================== */
#about {
  padding-top: 4.5rem;
}

.about-grid {
  max-width: 800px;
}

.about-text p {
  margin-bottom: var(--spacing-sm);
  font-size: 1.1rem;
  color: var(--color-text-secondary);
}

.about-text p:last-child {
  margin-bottom: 0;
}

/* ==========================================
   EDUCATION & TIMELINE SECTION
   ========================================== */
.education-grid {
  display: grid;
  grid-template-columns: 1.25fr 0.75fr;
  gap: var(--spacing-lg);
  align-items: flex-start;
}

.timeline {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.timeline-item {
  position: relative;
  padding-bottom: var(--spacing-md);
  border-bottom: 1px solid var(--color-border);
}

.timeline-item:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.timeline-card h3 {
  font-size: 1.45rem;
  font-weight: 600;
  margin-bottom: 0.15rem;
}

.timeline-meta {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-accent);
  margin-bottom: var(--spacing-sm);
}

.coursework-title {
  font-size: 0.9rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-primary);
  margin: var(--spacing-sm) 0 0.5rem;
}

.course-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.4rem 1rem;
  font-size: 0.95rem;
  color: var(--color-text-secondary);
}

.course-list li {
  font-size: 0.925rem;
  position: relative;
  padding-left: 0.75rem;
}

.course-list li::before {
  content: '•';
  color: var(--color-text-muted);
  position: absolute;
  left: 0;
}

.washu-photo {
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  overflow: hidden;
  margin-top: 52rem;
}

.washu-photo img {
  width: 100%;
  height: 340px;
  object-fit: cover;
}

/* ==========================================
   RESEARCH & WORK EXPERIENCE GRID
   ========================================== */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(310px, 1fr));
  gap: var(--spacing-md);
}

.card-icon {
  margin-bottom: var(--spacing-sm);
  color: var(--color-accent);
}

.card-icon svg {
  stroke-width: 1.5;
}

.card-title {
  font-size: 1.35rem;
  font-weight: 600;
  margin-bottom: 0.15rem;
}

.card-subtitle {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-sm);
  letter-spacing: -0.01em;
}

.card-desc {
  font-size: 0.98rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.card-link {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  font-size: 0.85rem;
  font-weight: 600;
  margin-top: var(--spacing-sm);
  color: var(--color-accent);
  border-bottom: none;
}

.card-link:hover {
  color: var(--color-accent-hover);
}

/* ==========================================
   RELEVANT PROJECTS
   ========================================== */
.projects-grid {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.project-large-card {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-lg);
  align-items: flex-start;
  padding: var(--spacing-lg);
}

.project-content h3 {
  font-size: 1.85rem;
  font-weight: 600;
  margin-bottom: 0.15rem;
}

.project-meta {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-accent);
  margin-bottom: var(--spacing-md);
}

.project-description {
  color: var(--color-text-secondary);
  font-size: 1rem;
  margin-bottom: var(--spacing-md);
  line-height: 1.65;
}

.project-awards {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--color-accent-light);
  border-left: 2px solid var(--color-accent);
  color: var(--color-text-primary);
  padding: 0.75rem var(--spacing-sm);
  margin-bottom: var(--spacing-md);
  font-size: 0.925rem;
}

.project-awards svg {
  width: 1.1rem;
  height: 1.1rem;
  fill: currentColor;
  flex-shrink: 0;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: var(--spacing-md);
}

.tag {
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  padding: 0.2rem 0.65rem;
  border-radius: var(--border-radius);
  font-size: 0.75rem;
  font-family: var(--font-mono);
  color: var(--color-text-secondary);
}

.project-links {
  display: flex;
  gap: var(--spacing-sm);
}

.project-gallery {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-sm);
}

.gallery-img {
  border-radius: var(--border-radius);
  overflow: hidden;
  border: 1px solid var(--color-border);
  aspect-ratio: 4/3;
}

.gallery-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.gallery-img.full-width {
  grid-column: span 2;
  aspect-ratio: 16/10;
}

.project-iframe-container {
  width: 100%;
  border-radius: var(--border-radius);
  overflow: hidden;
  border: 1px solid var(--color-border);
  margin-top: var(--spacing-sm);
}

.project-iframe-container iframe {
  width: 100%;
  height: 400px;
  border: none;
  background: #fdfdfd;
}

[data-theme="dark"] .project-iframe-container iframe {
  background: #121211;
}

/* ==========================================
   SKILLS SECTION (EDITORIAL TAGS)
   ========================================== */
.skills-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: var(--spacing-lg);
}

.skills-category {
  margin-bottom: var(--spacing-md);
}

.skills-category h3 {
  font-size: 1.45rem;
  font-weight: 600;
  margin-bottom: var(--spacing-md);
  border-bottom: 1px solid var(--color-border);
  padding-bottom: var(--spacing-xs);
}

.skills-subcategory {
  margin-bottom: var(--spacing-md);
}

.skills-subcategory h4 {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  margin-bottom: 0.5rem;
}

.skills-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.skill-pill {
  padding: 0.35rem 0.75rem;
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
  cursor: default;
}

.skill-pill:hover {
  background-color: var(--color-border-strong);
  color: var(--color-bg);
  border-color: var(--color-border-strong);
}

/* ==========================================
   CONTACT SECTION
   ========================================== */
.contact-grid {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: var(--spacing-lg);
  align-items: flex-start;
}

.contact-info h3 {
  font-size: 1.75rem;
  margin-bottom: var(--spacing-sm);
}

.contact-info p {
  color: var(--color-text-secondary);
  font-size: 1rem;
  margin-bottom: var(--spacing-md);
}

.contact-details {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.contact-item a {
  font-family: var(--font-mono);
  font-size: 0.9rem;
}

.contact-icon-wrapper {
  color: var(--color-accent);
}

.contact-form-card {
  padding: var(--spacing-md);
}

.form-group {
  margin-bottom: var(--spacing-md);
}

.form-label {
  display: block;
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--spacing-xs);
  color: var(--color-text-primary);
}

.form-input, .form-textarea {
  width: 100%;
  padding: 0.75rem;
  border-radius: var(--border-radius);
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  color: var(--color-text-primary);
  font-family: var(--font-sans);
  font-size: 0.95rem;
  transition: all var(--transition-fast);
}

.form-input:focus, .form-textarea:focus {
  outline: none;
  border-color: var(--color-text-primary);
  background-color: var(--color-bg);
}

.form-textarea {
  resize: vertical;
  min-height: 120px;
}

.form-status {
  margin-top: var(--spacing-sm);
  font-size: 0.95rem;
  font-weight: 500;
  display: none;
}

.form-status.success {
  color: var(--color-accent);
  display: block;
}

.form-status.error {
  color: #c2410c;
  display: block;
}

/* ==========================================
   FOOTER SECTION
   ========================================== */
.footer {
  padding: var(--spacing-lg) 0;
  border-top: 1px solid var(--color-border);
  text-align: center;
}

.footer-socials {
  display: flex;
  justify-content: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-sm);
}

.social-link {
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 50%;
  border: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
}

.social-link:hover {
  background-color: var(--color-border-strong);
  color: var(--color-bg);
  border-color: var(--color-border-strong);
  transform: translateY(-1px);
}

.social-link svg {
  width: 1rem;
  height: 1rem;
  fill: currentColor;
}

.footer-credits {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

/* ==========================================
   RESPONSIVE DESIGN Breakpoints
   ========================================== */

@media (max-width: 992px) {
  :root {
    --spacing-xxl: 5.5rem;
    --spacing-xl: 4.5rem;
    --spacing-lg: 2.5rem;
  }

  .hero-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
    text-align: center;
  }

  .hero-image-wrapper {
    order: -1;
  }

  .hero-buttons {
    justify-content: center;
  }

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

  .washu-photo {
    margin-top: 0;
  }

  .project-large-card {
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
  }

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

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

@media (max-width: 768px) {
  .nav-menu {
    position: fixed;
    top: 4.5rem;
    left: 0;
    width: 100%;
    height: 0;
    overflow: hidden;
    background-color: var(--color-bg);
    flex-direction: column;
    padding: 0;
    gap: 0;
    border-bottom: none;
    transition: height 0.35s cubic-bezier(0.77, 0, 0.175, 1);
  }

  .nav-menu.active {
    height: calc(100vh - 4.5rem);
    padding: var(--spacing-md) 0;
    border-bottom: 1px solid var(--color-border);
    overflow-y: auto;
  }

  .nav-menu li {
    width: 100%;
    text-align: center;
  }

  .nav-link {
    display: block;
    padding: 1rem 0;
    font-size: 1.1rem;
  }

  .theme-toggle-li {
    margin-top: var(--spacing-md);
  }

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

  .course-list {
    grid-template-columns: 1fr;
  }

  .washu-photo img {
    height: 240px;
  }
}