/* ===================================
   DESIGN SYSTEM VARIABLES
   =================================== */

:root {
  /* Primary - Deep Teal */
  --color-primary-50: #EEF5F7;
  --color-primary-100: #D4E8EC;
  --color-primary-200: #A8D0D9;
  --color-primary-300: #6BAEBB;
  --color-primary-400: #3D8F9F;
  --color-primary-500: #1B6B7D;
  --color-primary-600: #165A69;
  --color-primary-700: #114855;
  --color-primary-800: #0D3641;
  --color-primary-900: #08242D;

  /* Secondary - Warm Bronze */
  --color-secondary-50: #FBF5EF;
  --color-secondary-100: #F5E6D5;
  --color-secondary-200: #EBCCAA;
  --color-secondary-300: #D9A876;
  --color-secondary-400: #C8956A;
  --color-secondary-500: #A0724A;
  --color-secondary-600: #86603E;
  --color-secondary-700: #6C4D32;
  --color-secondary-800: #523B26;
  --color-secondary-900: #38281A;

  /* Accent - Muted Gold */
  --color-accent-50: #FDF8F0;
  --color-accent-100: #F9EDDA;
  --color-accent-200: #F2D9B1;
  --color-accent-300: #E8C084;
  --color-accent-400: #DBA85C;
  --color-accent-500: #C8956A;
  --color-accent-600: #B07D4F;
  --color-accent-700: #8F6540;
  --color-accent-800: #6E4E31;
  --color-accent-900: #4D3622;

  /* Neutrals - Warm */
  --color-gray-50: #FAF8F5;
  --color-gray-100: #F3F0EB;
  --color-gray-200: #E6E2DC;
  --color-gray-300: #D1CCC4;
  --color-gray-400: #9E9890;
  --color-gray-500: #716B63;
  --color-gray-600: #524D46;
  --color-gray-700: #3A3632;
  --color-gray-800: #252220;
  --color-gray-900: #1A1816;

  /* Semantic Colors */
  --color-bg-primary: #FDFCFA;
  --color-bg-secondary: #F7F5F1;
  --color-bg-tertiary: #F0EDE8;
  --color-text-primary: #1A1816;
  --color-text-secondary: #524D46;
  --color-text-tertiary: #716B63;
  --color-text-inverse: #FDFCFA;
  --color-border-light: #E6E2DC;
  --color-border-medium: #D1CCC4;

  /* Typography */
  --font-heading: 'Instrument Serif', Georgia, 'Times New Roman', serif;
  --font-body: 'Outfit', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'Courier New', monospace;

  /* Font Sizes */
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  --font-size-5xl: 3rem;
  --font-size-6xl: 3.75rem;

  /* Spacing */
  --spacing-1: 0.25rem;
  --spacing-2: 0.5rem;
  --spacing-3: 0.75rem;
  --spacing-4: 1rem;
  --spacing-5: 1.25rem;
  --spacing-6: 1.5rem;
  --spacing-8: 2rem;
  --spacing-10: 2.5rem;
  --spacing-12: 3rem;
  --spacing-16: 4rem;
  --spacing-20: 5rem;
  --spacing-24: 6rem;

  /* Layout */
  --max-width: 1200px;
  --max-width-narrow: 800px;

  /* Transitions */
  --ease-out: cubic-bezier(0, 0, 0.2, 1);
  --duration-normal: 250ms;
}

/* ===================================
   RESET & BASE STYLES
   =================================== */

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--color-text-primary);
  background: var(--color-bg-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  position: relative;
}

/* Subtle grain texture overlay */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 9999;
  opacity: 0.03;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
  background-repeat: repeat;
  background-size: 256px 256px;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  line-height: 1.15;
  font-weight: 400;
  font-style: italic;
}

a {
  color: inherit;
  text-decoration: none;
}

ul {
  list-style: none;
}

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

/* ===================================
   UTILITY CLASSES
   =================================== */

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-6);
}

.container-narrow {
  max-width: var(--max-width-narrow);
  margin: 0 auto;
  padding: 0 var(--spacing-6);
}

.skip-to-content {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--color-primary-600);
  color: white;
  padding: var(--spacing-2) var(--spacing-4);
  border-radius: 0 0 4px 0;
  z-index: 1000;
}

.skip-to-content:focus {
  top: 0;
}

/* ===================================
   NAVIGATION
   =================================== */

.nav {
  background: var(--color-bg-primary);
  border-bottom: 1px solid var(--color-border-light);
  padding: var(--spacing-4) 0;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  transition: all 0.3s ease;
}

.nav-scrolled {
  box-shadow: 0 1px 8px rgba(26, 24, 22, 0.06);
}

.nav-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-family: var(--font-heading);
  font-size: 1.4rem;
  font-weight: 400;
  font-style: italic;
  color: var(--color-primary-600);
  letter-spacing: 0.02em;
}

.nav-links {
  display: flex;
  gap: var(--spacing-8);
  align-items: center;
}

.nav-link {
  font-size: var(--font-size-base);
  font-weight: 500;
  color: var(--color-text-secondary);
  position: relative;
  padding: var(--spacing-2) 0;
  transition: color 0.2s ease;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 1.5px;
  background: var(--color-secondary-500);
  transition: width 0.3s ease;
}

.nav-link:hover {
  color: var(--color-primary-600);
}

.nav-link:hover::after {
  width: 100%;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-2);
  color: var(--color-text-primary);
}

.mobile-nav {
  display: none;
  position: fixed;
  top: 65px;
  left: 0;
  right: 0;
  background: white;
  border-bottom: 1px solid var(--color-border-light);
  padding: var(--spacing-4) var(--spacing-6);
  z-index: 99;
}

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

.mobile-nav-links {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-4);
}

/* ===================================
   HERO SECTION
   =================================== */

.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: var(--spacing-24) 0 var(--spacing-16);
  position: relative;
  overflow: hidden;
}

.hero .container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-12);
  align-items: center;
}

.bg-neural-pattern {
  background-color: var(--color-bg-secondary);
  background-image:
    radial-gradient(circle at 20% 50%, rgba(27, 107, 125, 0.04) 0%, transparent 50%),
    radial-gradient(circle at 80% 80%, rgba(160, 114, 74, 0.04) 0%, transparent 50%),
    radial-gradient(circle at 40% 20%, rgba(200, 149, 106, 0.03) 0%, transparent 50%);
}

.hero-intro {
  font-size: var(--font-size-lg);
  color: var(--color-primary-600);
  font-weight: 500;
  margin-bottom: var(--spacing-2);
}

.hero-title {
  font-size: clamp(3rem, 6vw, 4.5rem);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-4);
  letter-spacing: -0.02em;
  line-height: 1.05;
}

.hero-tagline {
  font-family: var(--font-heading);
  font-size: var(--font-size-2xl);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-6);
  font-weight: 500;
}

.hero-description {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-8);
  max-width: 540px;
}

.hero-cta {
  display: flex;
  gap: var(--spacing-4);
  flex-wrap: wrap;
}

/* Neural Animation */
.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: var(--spacing-6);
}

.hero-headshot {
  position: relative;
  z-index: 1;
}

.headshot-img {
  width: 200px;
  height: 200px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--color-secondary-200);
  box-shadow:
    0 20px 40px rgba(160, 114, 74, 0.12),
    0 0 0 8px rgba(160, 114, 74, 0.04);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.headshot-img:hover {
  transform: scale(1.02);
  box-shadow:
    0 25px 50px rgba(160, 114, 74, 0.16),
    0 0 0 12px rgba(160, 114, 74, 0.06);
}

.neural-animation {
  position: relative;
  width: 220px;
  height: 220px;
}

.node {
  position: absolute;
  width: 14px;
  height: 14px;
  background: linear-gradient(135deg, var(--color-primary-400), var(--color-secondary-400));
  border-radius: 50%;
  animation: pulse 2.5s ease-in-out infinite;
}

.node-1 { top: 66px; left: 31px; animation-delay: 0s; }
.node-2 { top: 31px; left: 104px; animation-delay: 0.3s; }
.node-3 { top: 66px; left: 177px; animation-delay: 0.6s; }
.node-4 { top: 141px; left: 67px; animation-delay: 0.9s; }
.node-5 { top: 104px; left: 104px; animation-delay: 1.2s; }

.connections {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

.connection {
  stroke: var(--color-primary-300);
  stroke-width: 2;
  opacity: 0.4;
  animation: connectionPulse 3s ease-in-out infinite;
}

.connection:nth-child(odd) {
  animation-delay: 0.5s;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 0.8; }
  50% { transform: scale(1.3); opacity: 1; }
}

@keyframes connectionPulse {
  0%, 100% { opacity: 0.2; }
  50% { opacity: 0.6; }
}

/* Stagger Animation */
.stagger-children > * {
  animation: fadeInUp 0.6s var(--ease-out) forwards;
  opacity: 0;
}

.stagger-children > *:nth-child(1) { animation-delay: 0.1s; }
.stagger-children > *:nth-child(2) { animation-delay: 0.2s; }
.stagger-children > *:nth-child(3) { animation-delay: 0.3s; }
.stagger-children > *:nth-child(4) { animation-delay: 0.4s; }
.stagger-children > *:nth-child(5) { animation-delay: 0.5s; }
.stagger-children > *:nth-child(6) { animation-delay: 0.6s; }

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===================================
   SECTIONS
   =================================== */

.section {
  padding: var(--spacing-20) 0;
}

.section-alt {
  background: var(--color-bg-secondary);
}

.section-title {
  font-size: var(--font-size-3xl);
  text-align: center;
  margin-bottom: var(--spacing-4);
  color: var(--color-text-primary);
}

.section-subtitle {
  text-align: center;
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-12);
  font-size: var(--font-size-lg);
}

/* ===================================
   ABOUT SECTION
   =================================== */

.about-content {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
}

.about-content p {
  margin-bottom: var(--spacing-6);
}

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

.about-cta {
  margin-top: var(--spacing-8);
  padding-top: var(--spacing-6);
  border-top: 1px solid var(--color-border-light);
}

/* ===================================
   BUTTONS
   =================================== */

.btn {
  font-family: var(--font-body);
  font-size: var(--font-size-base);
  font-weight: 500;
  line-height: 1.5;
  padding: var(--spacing-3) var(--spacing-6);
  border-radius: 8px;
  border: none;
  cursor: pointer;
  transition: all 0.2s ease-in-out;
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-2);
  text-decoration: none;
}

.btn svg {
  width: 18px;
  height: 18px;
}

.btn-primary {
  background: var(--color-primary-600);
  color: var(--color-text-inverse);
  box-shadow: 0 2px 8px rgba(27, 107, 125, 0.18);
}

.btn-primary:hover {
  background: var(--color-primary-700);
  box-shadow: 0 4px 12px rgba(27, 107, 125, 0.25);
  transform: translateY(-1px);
}

.btn-secondary {
  background: var(--color-bg-primary);
  color: var(--color-primary-600);
  border: 2px solid var(--color-primary-500);
}

.btn-secondary:hover {
  background: var(--color-primary-50);
  border-color: var(--color-primary-600);
  transform: translateY(-1px);
}

.btn-ghost {
  background: transparent;
  color: var(--color-text-secondary);
  padding: var(--spacing-2) var(--spacing-3);
}

.btn-ghost:hover {
  background: var(--color-gray-100);
  color: var(--color-text-primary);
}

.btn-sm {
  font-size: var(--font-size-sm);
  padding: var(--spacing-2) var(--spacing-3);
}

.btn-sm svg {
  width: 16px;
  height: 16px;
}

/* ===================================
   LINKS
   =================================== */

.link {
  color: var(--color-primary-600);
  font-weight: 500;
  transition: color 0.2s ease;
}

.link:hover {
  color: var(--color-primary-700);
}

.link-underline {
  text-decoration: underline;
  text-decoration-color: var(--color-primary-300);
  text-underline-offset: 3px;
  text-decoration-thickness: 2px;
}

.link-underline:hover {
  text-decoration-color: var(--color-primary-600);
}

/* ===================================
   CARDS
   =================================== */

.card {
  background: var(--color-bg-primary);
  border: 1px solid var(--color-border-light);
  border-radius: 12px;
  padding: var(--spacing-6);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary-500), var(--color-secondary-400));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s ease-in-out;
}

.card:hover {
  border-color: var(--color-secondary-200);
  box-shadow: 0 8px 24px rgba(160, 114, 74, 0.07), 0 2px 8px rgba(0, 0, 0, 0.03);
  transform: translateY(-3px);
}

.card:hover::before {
  transform: scaleX(1);
}

.card-featured {
  background: linear-gradient(135deg, var(--color-primary-50) 0%, var(--color-secondary-50) 100%);
  border: 2px solid var(--color-secondary-200);
}

.card-featured::before {
  transform: scaleX(1);
}

.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--spacing-4);
}

.card-title {
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-3);
}

.card-description {
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: var(--spacing-4);
}

.card-footer {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  margin-top: var(--spacing-6);
  padding-top: var(--spacing-4);
  border-top: 1px solid var(--color-border-light);
}

/* ===================================
   PROJECTS
   =================================== */

.project-filters {
  display: flex;
  justify-content: center;
  gap: var(--spacing-2);
  margin-bottom: var(--spacing-8);
  flex-wrap: wrap;
}

.filter-btn {
  background: transparent;
  border: 1px solid var(--color-border-medium);
  padding: var(--spacing-2) var(--spacing-4);
  border-radius: 20px;
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all 0.2s ease;
}

.filter-btn:hover {
  border-color: var(--color-primary-400);
  color: var(--color-primary-600);
}

.filter-btn.active {
  background: var(--color-primary-500);
  border-color: var(--color-primary-500);
  color: white;
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: var(--spacing-6);
}

.project-card {
  display: flex;
  flex-direction: column;
  transition: opacity 0.3s ease, transform 0.3s ease;
}

.project-card.card-hidden {
  opacity: 0;
  transform: scale(0.95);
  pointer-events: none;
  position: absolute;
  visibility: hidden;
}

/* Project Card Thumbnails */
.card-thumbnail {
  height: 140px;
  border-radius: 12px 12px 0 0;
  margin: calc(var(--spacing-6) * -1) calc(var(--spacing-6) * -1) var(--spacing-4);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.card-thumbnail svg {
  width: 48px;
  height: 48px;
  color: rgba(255, 255, 255, 0.9);
  filter: drop-shadow(0 2px 8px rgba(0, 0, 0, 0.3));
}

.card-thumbnail::after {
  content: '';
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(
    45deg,
    transparent,
    transparent 20px,
    rgba(255, 255, 255, 0.03) 20px,
    rgba(255, 255, 255, 0.03) 40px
  );
}

/* Cards with thumbnails: hide hover top-line, adjust border radius */
.project-card .card-thumbnail + .card-header {
  justify-content: flex-end;
}

/* Unique gradients per project theme */
.thumb-healthcare { background: linear-gradient(135deg, #1e40af 0%, #7c3aed 50%, #db2777 100%); }
.thumb-analytics { background: linear-gradient(135deg, #065f46 0%, #0d9488 50%, #06b6d4 100%); }
.thumb-edtech { background: linear-gradient(135deg, #92400e 0%, #d97706 50%, #fbbf24 100%); }
.thumb-simulation { background: linear-gradient(135deg, #1e3a5f 0%, #3b82f6 50%, #93c5fd 100%); }
.thumb-neuro { background: linear-gradient(135deg, #4c1d95 0%, #7c3aed 50%, #a78bfa 100%); }
.thumb-vision { background: linear-gradient(135deg, #0f766e 0%, #2dd4bf 50%, #99f6e4 100%); }
.thumb-bci { background: linear-gradient(135deg, #581c87 0%, #9333ea 50%, #c084fc 100%); }
.thumb-genomics { background: linear-gradient(135deg, #164e63 0%, #0891b2 50%, #67e8f9 100%); }
.thumb-connectome { background: linear-gradient(135deg, #312e81 0%, #6366f1 50%, #a5b4fc 100%); }
.thumb-imaging { background: linear-gradient(135deg, #7f1d1d 0%, #dc2626 50%, #f87171 100%); }

/* Card descriptions */
.card-description {
  flex: 1;
}

.project-icon {
  width: 48px;
  height: 48px;
  background: var(--color-primary-50);
  border: 1px solid var(--color-primary-200);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary-600);
}

.project-icon svg {
  width: 24px;
  height: 24px;
}

.project-status {
  font-size: var(--font-size-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: var(--spacing-1) var(--spacing-2);
  border-radius: 4px;
}

.status-completed {
  background: #DCFCE7;
  color: #166534;
}

.status-live {
  background: linear-gradient(135deg, #DCFCE7, #D1FAE5);
  color: #059669;
  animation: pulse-live 2s ease-in-out infinite;
}

@keyframes pulse-live {
  0%, 100% { box-shadow: 0 0 0 0 rgba(5, 150, 105, 0.2); }
  50% { box-shadow: 0 0 0 4px rgba(5, 150, 105, 0.1); }
}

.status-in-progress {
  background: #FEF3C7;
  color: #92400E;
}

.status-planned {
  background: var(--color-gray-100);
  color: var(--color-gray-600);
}

/* ===================================
   TAGS
   =================================== */

.tag-group {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-2);
}

.tag {
  display: inline-flex;
  align-items: center;
  padding: var(--spacing-1) var(--spacing-3);
  font-size: var(--font-size-sm);
  font-weight: 500;
  border-radius: 6px;
  transition: all 0.2s ease;
}

.tag-primary {
  background: var(--color-primary-50);
  color: var(--color-primary-700);
  border: 1px solid var(--color-primary-200);
}

.tag-secondary {
  background: var(--color-secondary-50);
  color: var(--color-secondary-700);
  border: 1px solid var(--color-secondary-200);
}

.tag-accent {
  background: var(--color-accent-50);
  color: var(--color-accent-800);
  border: 1px solid var(--color-accent-200);
}

.tag-neutral {
  background: var(--color-gray-100);
  color: var(--color-gray-700);
  border: 1px solid var(--color-gray-200);
}

/* ===================================
   SKILLS SECTION
   =================================== */

.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-8);
}

.skill-category {
  background: var(--color-bg-primary);
  padding: var(--spacing-6);
  border-radius: 12px;
  border: 1px solid var(--color-border-light);
}

.skill-category-title {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-4);
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
}

.skill-category-title svg {
  width: 20px;
  height: 20px;
  color: var(--color-primary-500);
}

/* ===================================
   CONTACT SECTION
   =================================== */

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

.contact-content p {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-4);
}

.contact-interests {
  background: var(--color-bg-primary);
  padding: var(--spacing-6);
  border-radius: 12px;
  margin: var(--spacing-8) 0;
  text-align: left;
}

.contact-interests h3 {
  font-size: var(--font-size-base);
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-4);
}

.contact-interests ul {
  list-style: disc;
  padding-left: var(--spacing-6);
}

.contact-interests li {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-2);
}

.contact-links {
  display: flex;
  justify-content: center;
  gap: var(--spacing-4);
  flex-wrap: wrap;
  margin-top: var(--spacing-8);
}

.contact-link {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  padding: var(--spacing-3) var(--spacing-5);
  background: var(--color-bg-primary);
  border: 1px solid var(--color-border-light);
  border-radius: 8px;
  color: var(--color-text-secondary);
  font-weight: 500;
  transition: all 0.2s ease;
}

.contact-link:hover {
  border-color: var(--color-primary-400);
  color: var(--color-primary-600);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

.contact-link svg {
  width: 20px;
  height: 20px;
}

/* ===================================
   FOOTER
   =================================== */

.footer {
  background: var(--color-gray-900);
  color: var(--color-gray-400);
  padding: var(--spacing-10) 0;
  text-align: center;
  font-size: var(--font-size-sm);
  border-top: 1px solid var(--color-gray-800);
}

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

@media (max-width: 768px) {
  .nav-links {
    display: none;
  }

  .nav-toggle {
    display: block;
  }

  .hero .container {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-title {
    font-size: var(--font-size-4xl);
  }

  .hero-tagline {
    font-size: var(--font-size-xl);
  }

  .hero-description {
    margin-left: auto;
    margin-right: auto;
  }

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

  .hero-visual {
    order: -1;
    margin-bottom: var(--spacing-8);
    flex-direction: column;
    gap: var(--spacing-4);
  }

  .headshot-img {
    width: 150px;
    height: 150px;
  }

  .neural-animation {
    width: 160px;
    height: 160px;
  }

  .section {
    padding: var(--spacing-12) 0;
  }

  .section-title {
    font-size: var(--font-size-2xl);
  }

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

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

  .contact-links {
    flex-direction: column;
    align-items: stretch;
  }

  .contact-link {
    justify-content: center;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: var(--font-size-3xl);
  }

  .btn {
    width: 100%;
    justify-content: center;
  }

  .hero-cta {
    flex-direction: column;
  }
}

/* ===================================
   FOCUS STATES (Accessibility)
   =================================== */

*:focus-visible {
  outline: 2px solid var(--color-primary-500);
  outline-offset: 2px;
  border-radius: 4px;
}

/* ===================================
   REDUCED MOTION
   =================================== */

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

  html {
    scroll-behavior: auto;
  }
}

/* ===================================
   NEURAL NETWORK GAME
   =================================== */

.game-container {
  background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
  border-radius: 16px;
  padding: var(--spacing-6);
  border: 1px solid rgba(71, 85, 105, 0.5);
  box-shadow:
    0 4px 6px -1px rgba(0, 0, 0, 0.1),
    0 2px 4px -1px rgba(0, 0, 0, 0.06),
    inset 0 1px 0 rgba(255, 255, 255, 0.05);
}

.game-container canvas {
  width: 100%;
  height: min(400px, 50vh);
  border-radius: 12px;
  display: block;
}

.game-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: var(--spacing-5);
  padding-top: var(--spacing-5);
  border-top: 1px solid rgba(71, 85, 105, 0.5);
  flex-wrap: wrap;
  gap: var(--spacing-4);
}

.game-info {
  display: flex;
  gap: var(--spacing-6);
}

.game-stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  background: rgba(30, 41, 59, 0.8);
  padding: var(--spacing-3) var(--spacing-5);
  border-radius: 10px;
  border: 1px solid rgba(71, 85, 105, 0.3);
  min-width: 80px;
}

.stat-label {
  font-size: var(--font-size-xs);
  color: #94a3b8;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 600;
  margin-bottom: var(--spacing-1);
}

.stat-value {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: #f1f5f9;
  font-family: var(--font-mono);
}

.game-buttons {
  display: flex;
  gap: var(--spacing-3);
}

.game-buttons .btn {
  background: rgba(102, 126, 234, 0.2);
  border: 1px solid rgba(102, 126, 234, 0.4);
  color: #c7d2fe;
  padding: var(--spacing-3) var(--spacing-5);
  font-weight: 600;
  transition: all 0.2s ease;
}

.game-buttons .btn:hover {
  background: rgba(102, 126, 234, 0.3);
  border-color: rgba(102, 126, 234, 0.6);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
}

.game-buttons .btn.active {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border-color: transparent;
  color: #fff;
  box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.game-buttons .btn-primary {
  background: linear-gradient(135deg, #22c55e 0%, #16a34a 100%);
  border-color: transparent;
  color: #fff;
}

.game-buttons .btn-primary:hover {
  background: linear-gradient(135deg, #16a34a 0%, #15803d 100%);
  box-shadow: 0 4px 15px rgba(34, 197, 94, 0.4);
}

.game-buttons .btn-secondary {
  background: rgba(239, 68, 68, 0.2);
  border-color: rgba(239, 68, 68, 0.4);
  color: #fca5a5;
}

.game-buttons .btn-secondary:hover {
  background: rgba(239, 68, 68, 0.3);
  border-color: rgba(239, 68, 68, 0.6);
  color: #fff;
  box-shadow: 0 4px 12px rgba(239, 68, 68, 0.3);
}

.game-hint {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-2);
  margin-top: var(--spacing-4);
  padding: var(--spacing-3) var(--spacing-4);
  background: rgba(102, 126, 234, 0.1);
  border: 1px solid rgba(102, 126, 234, 0.2);
  border-radius: 8px;
  font-size: var(--font-size-sm);
  color: #a5b4fc;
}

.game-hint svg {
  width: 16px;
  height: 16px;
  color: #818cf8;
}

/* Problem Select Dropdown */
.problem-select {
  background: rgba(30, 41, 59, 0.9);
  border: 1px solid rgba(102, 126, 234, 0.4);
  border-radius: 8px;
  padding: var(--spacing-2) var(--spacing-3);
  font-family: var(--font-mono);
  font-size: var(--font-size-base);
  font-weight: 600;
  color: #c7d2fe;
  cursor: pointer;
  transition: all 0.2s ease;
  appearance: none;
  -webkit-appearance: none;
  -moz-appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%23a5b4fc' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 10px center;
  padding-right: var(--spacing-8);
  min-width: 90px;
}

.problem-select:hover {
  border-color: rgba(102, 126, 234, 0.7);
  background-color: rgba(30, 41, 59, 1);
}

.problem-select:focus {
  outline: none;
  border-color: #667eea;
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.3);
}

.problem-select option {
  background: #1e293b;
  color: #e2e8f0;
  padding: var(--spacing-2);
}

/* ===================================
   HIGHLIGHTS GRID (HOME PAGE)
   =================================== */

.highlights-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-6);
  margin-bottom: var(--spacing-8);
}

.highlight-card {
  background: var(--color-bg-primary);
  border: 1px solid var(--color-border-light);
  border-radius: 12px;
  padding: var(--spacing-6);
  text-align: center;
  transition: all 0.3s ease;
}

.highlight-card:hover {
  border-color: var(--color-secondary-200);
  box-shadow: 0 8px 24px rgba(160, 114, 74, 0.08);
  transform: translateY(-3px);
}

.highlight-icon {
  width: 56px;
  height: 56px;
  background: var(--color-primary-50);
  border: 1px solid var(--color-primary-200);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--spacing-4);
  color: var(--color-primary-600);
}

.highlight-icon svg {
  width: 32px;
  height: 32px;
}

.highlight-card h3 {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-2);
}

.highlight-card p {
  color: var(--color-text-secondary);
  font-size: var(--font-size-base);
  line-height: 1.6;
}

.section-cta {
  text-align: center;
  margin-top: var(--spacing-8);
}

/* ===================================
   FEATURED PROJECT
   =================================== */

.featured-project {
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border-light);
  border-radius: 16px;
  padding: var(--spacing-8);
  position: relative;
  overflow: hidden;
}

.featured-project::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-secondary-400), var(--color-primary-500));
}

.featured-badge {
  display: inline-block;
  background: linear-gradient(135deg, #f59e0b, #d97706);
  color: white;
  font-size: var(--font-size-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: var(--spacing-1) var(--spacing-3);
  border-radius: 4px;
  margin-bottom: var(--spacing-4);
}

.featured-content h3 {
  font-size: var(--font-size-2xl);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-4);
}

.featured-content p {
  color: var(--color-text-secondary);
  font-size: var(--font-size-lg);
  line-height: 1.7;
  margin-bottom: var(--spacing-4);
}

.featured-award {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  color: #b45309;
  font-size: var(--font-size-base);
  margin-bottom: var(--spacing-4);
}

.featured-award svg {
  width: 20px;
  height: 20px;
  color: #f59e0b;
}

.featured-content .tag-group {
  margin-bottom: var(--spacing-6);
}

/* ===================================
   PAGE HEADER
   =================================== */

.page-header {
  background: var(--color-bg-secondary);
  padding: var(--spacing-24) 0 var(--spacing-12);
  text-align: center;
}

.page-title {
  font-size: var(--font-size-4xl);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-4);
}

.page-subtitle {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

/* ===================================
   NAV ACTIVE STATE
   =================================== */

.nav-link.active {
  color: var(--color-primary-600);
}

.nav-link.active::after {
  width: 100%;
}

/* ===================================
   FOOTER IMPROVEMENTS
   =================================== */

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-4);
}

.footer-links {
  display: flex;
  gap: var(--spacing-4);
}

.footer-links a {
  color: var(--color-gray-400);
  transition: color 0.2s ease;
}

.footer-links a:hover {
  color: var(--color-primary-400);
}

.footer-links svg {
  width: 20px;
  height: 20px;
}

/* ===================================
   ABOUT PAGE STYLES
   =================================== */

.about-content-full {
  max-width: 720px;
  margin: 0 auto;
}

.about-headshot-section {
  display: flex;
  justify-content: center;
  margin-top: calc(-1 * var(--spacing-6));
  margin-bottom: var(--spacing-10);
}

.about-headshot {
  width: 260px;
  height: 260px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--color-secondary-200);
  box-shadow:
    0 12px 24px rgba(160, 114, 74, 0.1),
    0 0 0 6px rgba(160, 114, 74, 0.03);
}

.about-intro {
  margin-bottom: var(--spacing-10);
}

.about-lead {
  font-size: var(--font-size-xl);
  color: var(--color-text-secondary);
  line-height: 1.8;
}

.about-lead strong {
  color: var(--color-primary-600);
  font-weight: 600;
}

.about-section {
  margin-bottom: var(--spacing-10);
  padding-bottom: var(--spacing-8);
  border-bottom: 1px solid var(--color-border-light);
}

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

.about-section h2 {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
  font-size: var(--font-size-xl);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-5);
}

.about-section h2 svg {
  width: 24px;
  height: 24px;
  color: var(--color-primary-500);
}

.about-section p {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  line-height: 1.8;
  margin-bottom: var(--spacing-4);
}

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

.about-section em {
  color: var(--color-text-primary);
  font-style: italic;
}

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

.achievement-card {
  display: flex;
  gap: var(--spacing-5);
  background: linear-gradient(135deg, #fef3c7 0%, #fef9c3 100%);
  border: 1px solid #fcd34d;
  border-radius: 14px;
  padding: var(--spacing-6);
}

.achievement-icon {
  width: 56px;
  height: 56px;
  background: linear-gradient(135deg, #f59e0b, #d97706);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.achievement-icon svg {
  width: 28px;
  height: 28px;
  color: white;
}

.achievement-content h3 {
  font-size: var(--font-size-lg);
  color: #92400e;
  margin-bottom: var(--spacing-2);
}

.achievement-content p {
  font-size: var(--font-size-base);
  color: #78350f;
  margin: 0;
}

.achievement-content a {
  color: #b45309;
  font-weight: 600;
}

.education-card {
  display: flex;
  gap: var(--spacing-5);
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border-light);
  border-radius: 14px;
  padding: var(--spacing-6);
}

.education-logo {
  width: 64px;
  height: 64px;
  background: var(--color-primary-600);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-heading);
  font-size: var(--font-size-xl);
  font-weight: 400;
  font-style: italic;
  color: white;
  flex-shrink: 0;
}

.education-content h3 {
  font-size: var(--font-size-lg);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-2);
}

.education-degree {
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  font-weight: 500;
  margin-bottom: var(--spacing-1);
}

.education-details {
  font-size: var(--font-size-sm);
  color: var(--color-text-tertiary);
  margin-bottom: var(--spacing-1);
}

.education-year {
  font-size: var(--font-size-sm);
  color: var(--color-primary-600);
  font-weight: 600;
}

.interests-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-4);
}

.interest-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border-light);
  border-radius: 10px;
  padding: var(--spacing-4);
  transition: all 0.2s ease;
}

.interest-item:hover {
  border-color: var(--color-primary-300);
  background: var(--color-primary-50);
  transform: translateX(4px);
}

.interest-item svg {
  width: 22px;
  height: 22px;
  color: var(--color-primary-500);
}

.interest-item span {
  font-weight: 500;
  color: var(--color-text-primary);
}

.about-cta-section {
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border-light);
  border-radius: 16px;
  padding: var(--spacing-8);
  text-align: center;
  margin-top: var(--spacing-10);
}

.about-cta-section p {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-6);
}

.about-grid {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: var(--spacing-12);
  align-items: start;
}

.about-main h2 {
  font-size: var(--font-size-2xl);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-4);
  margin-top: var(--spacing-8);
}

.about-main h2:first-child {
  margin-top: 0;
}

.about-main p {
  color: var(--color-text-secondary);
  font-size: var(--font-size-lg);
  line-height: 1.7;
  margin-bottom: var(--spacing-4);
}

.about-sidebar {
  position: sticky;
  top: 100px;
}

.about-card {
  background: var(--color-bg-primary);
  border: 1px solid var(--color-border-light);
  border-radius: 12px;
  padding: var(--spacing-6);
  margin-bottom: var(--spacing-6);
}

.about-card h3 {
  font-size: var(--font-size-lg);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-4);
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
}

.about-card svg {
  width: 20px;
  height: 20px;
  color: var(--color-primary-500);
}

.about-card ul {
  list-style: none;
}

.about-card li {
  color: var(--color-text-secondary);
  padding: var(--spacing-2) 0;
  border-bottom: 1px solid var(--color-border-light);
}

.about-card li:last-child {
  border-bottom: none;
}

/* ===================================
   SKILLS PAGE STYLES
   =================================== */

.skills-grid-full {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-8);
  margin-bottom: var(--spacing-12);
}

.skill-category-card {
  background: var(--color-bg-primary);
  border: 1px solid var(--color-border-light);
  border-radius: 16px;
  padding: var(--spacing-8);
  transition: all 0.3s ease;
}

.skill-category-card:hover {
  border-color: var(--color-secondary-200);
  box-shadow: 0 8px 30px rgba(160, 114, 74, 0.07);
  transform: translateY(-2px);
}

.skill-category-header {
  display: flex;
  align-items: center;
  gap: var(--spacing-4);
  margin-bottom: var(--spacing-6);
  padding-bottom: var(--spacing-4);
  border-bottom: 1px solid var(--color-border-light);
}

.skill-category-icon {
  width: 56px;
  height: 56px;
  background: var(--color-primary-50);
  border: 1px solid var(--color-primary-200);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary-600);
  flex-shrink: 0;
}

.skill-category-icon svg {
  width: 28px;
  height: 28px;
}

.skill-category-icon.accent {
  background: linear-gradient(135deg, var(--color-accent-100), var(--color-accent-50));
  color: var(--color-accent-700);
}

.skill-category-icon.secondary {
  background: linear-gradient(135deg, var(--color-secondary-100), var(--color-secondary-50));
  color: var(--color-secondary-600);
}

.skill-category-icon.neutral {
  background: linear-gradient(135deg, var(--color-gray-200), var(--color-gray-100));
  color: var(--color-gray-700);
}

.skill-category-header h2 {
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--color-text-primary);
  margin: 0;
}

.skill-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-4);
}

.skill-item {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-2);
}

.skill-name {
  font-size: var(--font-size-base);
  font-weight: 500;
  color: var(--color-text-primary);
}

.skill-bar {
  height: 10px;
  background: var(--color-gray-100);
  border-radius: 5px;
  overflow: hidden;
  position: relative;
}

.skill-bar::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: repeating-linear-gradient(
    90deg,
    transparent,
    transparent 2px,
    rgba(255,255,255,0.1) 2px,
    rgba(255,255,255,0.1) 4px
  );
}

.skill-level {
  height: 100%;
  background: linear-gradient(90deg, var(--color-primary-400), var(--color-primary-600));
  border-radius: 5px;
  transition: width 1s ease;
  position: relative;
}

.skill-bar.accent .skill-level {
  background: linear-gradient(90deg, var(--color-accent-400), var(--color-accent-600));
}

.skill-bar.secondary .skill-level {
  background: linear-gradient(90deg, var(--color-secondary-400), var(--color-secondary-600));
}

.skill-bar.neutral .skill-level {
  background: linear-gradient(90deg, var(--color-gray-400), var(--color-gray-600));
}

.skills-section-divider {
  text-align: center;
  margin-bottom: var(--spacing-8);
}

.skills-section-divider h2 {
  font-size: var(--font-size-2xl);
  color: var(--color-text-primary);
  position: relative;
  display: inline-block;
}

.skills-section-divider h2::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary-500), var(--color-accent-500));
  border-radius: 2px;
}

.coursework-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--spacing-4);
}

.coursework-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
  background: var(--color-bg-primary);
  border: 1px solid var(--color-border-light);
  border-radius: 10px;
  padding: var(--spacing-4) var(--spacing-5);
  transition: all 0.2s ease;
}

.coursework-item:hover {
  border-color: var(--color-primary-300);
  background: var(--color-primary-50);
  transform: translateX(4px);
}

.coursework-item svg {
  width: 20px;
  height: 20px;
  color: var(--color-primary-500);
  flex-shrink: 0;
}

.coursework-item span {
  font-weight: 500;
  color: var(--color-text-primary);
}

/* ===================================
   CONTACT PAGE STYLES
   =================================== */

.contact-content-full {
  max-width: 720px;
  margin: 0 auto;
}

.contact-intro {
  margin-bottom: var(--spacing-10);
}

.contact-intro p {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  line-height: 1.8;
  margin-bottom: var(--spacing-4);
}

.contact-interests-card {
  background: linear-gradient(135deg, var(--color-primary-50), var(--color-accent-50));
  border: 1px solid var(--color-primary-200);
  border-radius: 16px;
  padding: var(--spacing-8);
  margin-bottom: var(--spacing-10);
}

.contact-interests-card h2 {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
  font-size: var(--font-size-lg);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-5);
}

.contact-interests-card h2 svg {
  width: 24px;
  height: 24px;
  color: var(--color-primary-500);
}

.contact-interests-card ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-3);
}

.contact-interests-card li {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-3);
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.contact-interests-card li svg {
  width: 20px;
  height: 20px;
  color: var(--color-primary-500);
  flex-shrink: 0;
  margin-top: 2px;
}

.contact-methods {
  margin-bottom: var(--spacing-10);
}

.contact-methods h2 {
  font-size: var(--font-size-xl);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-6);
  text-align: center;
}

.contact-cards {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-4);
}

.contact-card {
  display: flex;
  align-items: center;
  gap: var(--spacing-5);
  background: var(--color-bg-primary);
  border: 1px solid var(--color-border-light);
  border-radius: 14px;
  padding: var(--spacing-5) var(--spacing-6);
  transition: all 0.3s ease;
  text-decoration: none;
}

.contact-card:hover {
  border-color: var(--color-primary-300);
  transform: translateX(8px);
  box-shadow: 0 8px 24px rgba(19, 102, 240, 0.1);
}

.contact-card-icon {
  width: 56px;
  height: 56px;
  background: linear-gradient(135deg, var(--color-primary-100), var(--color-primary-50));
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary-600);
  flex-shrink: 0;
  transition: all 0.3s ease;
}

.contact-card:hover .contact-card-icon {
  background: linear-gradient(135deg, var(--color-primary-500), var(--color-primary-600));
  color: white;
}

.contact-card-icon.linkedin {
  background: linear-gradient(135deg, #e0f2fe, #dbeafe);
  color: #0077b5;
}

.contact-card:hover .contact-card-icon.linkedin {
  background: linear-gradient(135deg, #0077b5, #005582);
  color: white;
}

.contact-card-icon.github {
  background: linear-gradient(135deg, var(--color-gray-200), var(--color-gray-100));
  color: var(--color-gray-800);
}

.contact-card:hover .contact-card-icon.github {
  background: linear-gradient(135deg, var(--color-gray-800), var(--color-gray-900));
  color: white;
}

.contact-card-icon svg {
  width: 26px;
  height: 26px;
}

.contact-card-content h3 {
  font-size: var(--font-size-lg);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-1);
}

.contact-card-content p {
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  margin: 0;
}

/* Contact Form */
.contact-form-section {
  margin-bottom: var(--spacing-10);
}

.contact-form-section h2 {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-2);
  font-size: var(--font-size-2xl);
  margin-bottom: var(--spacing-2);
}

.contact-form-section h2 svg {
  width: 24px;
  height: 24px;
  color: var(--color-primary-500);
}

.contact-form-note {
  font-size: var(--font-size-sm);
  color: var(--color-primary-600);
  font-weight: 500;
  margin-bottom: var(--spacing-6);
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-5);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-5);
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-2);
}

.form-group label {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-text-secondary);
}

.form-group input,
.form-group select,
.form-group textarea {
  font-family: var(--font-body);
  font-size: var(--font-size-base);
  padding: var(--spacing-3) var(--spacing-4);
  border: 1px solid var(--color-border-medium);
  border-radius: 10px;
  background: var(--color-bg-primary);
  color: var(--color-text-primary);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--color-primary-500);
  box-shadow: 0 0 0 3px rgba(19, 102, 240, 0.1);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: var(--color-gray-400);
}

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

.form-group select {
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%236B7280' stroke-width='2'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: var(--spacing-10);
}

.btn-lg {
  padding: var(--spacing-4) var(--spacing-8);
  font-size: var(--font-size-lg);
  align-self: flex-start;
}

@media (max-width: 480px) {
  .form-row {
    grid-template-columns: 1fr;
  }

  .btn-lg {
    align-self: stretch;
  }
}

.contact-location {
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border-light);
  border-radius: 14px;
  padding: var(--spacing-6);
  text-align: center;
}

.contact-location h2 {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-2);
  font-size: var(--font-size-lg);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-3);
}

.contact-location h2 svg {
  width: 22px;
  height: 22px;
  color: var(--color-primary-500);
}

.contact-location p {
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-2);
}

.contact-note {
  font-size: var(--font-size-sm);
  color: var(--color-primary-600);
  font-weight: 500;
}

.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-6);
  margin-bottom: var(--spacing-8);
}

/* ===================================
   RESPONSIVE - GAME
   =================================== */

@media (max-width: 768px) {
  .game-container {
    padding: var(--spacing-4);
    border-radius: 12px;
  }

  .game-controls {
    flex-direction: column;
    align-items: stretch;
  }

  .game-info {
    justify-content: center;
    flex-wrap: wrap;
    gap: var(--spacing-2);
  }

  .game-buttons {
    justify-content: center;
    flex-wrap: wrap;
  }

  .game-stat {
    min-width: 60px;
    padding: var(--spacing-2);
  }

  .stat-label {
    font-size: 0.65rem;
  }

  .stat-value {
    font-size: var(--font-size-base);
  }

  .game-buttons .btn {
    padding: var(--spacing-2) var(--spacing-3);
    font-size: var(--font-size-sm);
  }

  .problem-select {
    font-size: var(--font-size-sm);
    padding: var(--spacing-1) var(--spacing-2);
  }

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

  .about-sidebar {
    position: static;
  }

  /* Skills page responsive */
  .skills-grid-full {
    grid-template-columns: 1fr;
    gap: var(--spacing-6);
  }

  .skill-category-card {
    padding: var(--spacing-6);
  }

  .skill-category-header {
    gap: var(--spacing-3);
    margin-bottom: var(--spacing-4);
    padding-bottom: var(--spacing-3);
  }

  .skill-category-icon {
    width: 48px;
    height: 48px;
  }

  .skill-category-icon svg {
    width: 24px;
    height: 24px;
  }

  .skill-category-header h2 {
    font-size: var(--font-size-lg);
  }

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

  /* About page responsive */
  .achievement-card {
    flex-direction: column;
    text-align: center;
  }

  .achievement-icon {
    margin: 0 auto;
  }

  .education-card {
    flex-direction: column;
    text-align: center;
  }

  .education-logo {
    margin: 0 auto;
  }

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

  /* Contact page responsive */
  .contact-card {
    flex-direction: column;
    text-align: center;
    padding: var(--spacing-6);
  }

  .contact-card:hover {
    transform: translateY(-4px);
  }

  .contact-card-icon {
    margin: 0 auto;
  }
}

/* ===================================
   ABOUT PAGE INTERACTIVES
   =================================== */

.about-interactives {
  margin-top: var(--spacing-12);
}

.interactives-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(380px, 100%), 1fr));
  gap: var(--spacing-8);
}

.interactive-card {
  background: linear-gradient(135deg, rgba(30, 41, 59, 0.9) 0%, rgba(15, 23, 42, 0.95) 100%);
  border: 1px solid rgba(102, 126, 234, 0.3);
  border-radius: var(--radius-xl);
  padding: var(--spacing-6);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.interactive-header {
  text-align: center;
  margin-bottom: var(--spacing-4);
}

.interactive-header h3 {
  font-family: var(--font-display);
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: #f8fafc;
  margin-bottom: var(--spacing-2);
}

.interactive-header p {
  color: #94a3b8;
  font-size: var(--font-size-sm);
}

.interactive-canvas-container {
  display: flex;
  justify-content: center;
  margin-bottom: var(--spacing-4);
}

.interactive-canvas-container canvas {
  border-radius: var(--radius-lg);
  max-width: 100%;
}

.interactive-controls {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-4);
  margin-top: var(--spacing-4);
}

.control-row {
  display: flex;
  align-items: center;
  gap: var(--spacing-4);
  flex-wrap: wrap;
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-1);
  flex: 1;
  min-width: 120px;
}

.control-label {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: var(--font-size-xs);
  color: #94a3b8;
  font-weight: 500;
}

.control-value {
  font-family: var(--font-mono);
  color: #c7d2fe;
}

.control-slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  border-radius: 3px;
  background: rgba(71, 85, 105, 0.5);
  outline: none;
  cursor: pointer;
}

.control-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  cursor: pointer;
  box-shadow: 0 2px 6px rgba(102, 126, 234, 0.4);
}

.control-slider::-moz-range-thumb {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  cursor: pointer;
  border: none;
  box-shadow: 0 2px 6px rgba(102, 126, 234, 0.4);
}

.control-select {
  background: rgba(30, 41, 59, 0.9);
  border: 1px solid rgba(102, 126, 234, 0.4);
  border-radius: 6px;
  padding: var(--spacing-2) var(--spacing-3);
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: #c7d2fe;
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%23a5b4fc' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 8px center;
  padding-right: var(--spacing-6);
}

.control-select:focus {
  outline: none;
  border-color: #667eea;
}

.control-select option {
  background: #1e293b;
  color: #e2e8f0;
}

.interactive-stats {
  display: flex;
  justify-content: center;
  gap: var(--spacing-4);
  padding: var(--spacing-3);
  background: rgba(15, 23, 42, 0.5);
  border-radius: var(--radius-md);
  margin-bottom: var(--spacing-4);
  flex-wrap: wrap;
}

.interactive-stat {
  text-align: center;
  min-width: 70px;
}

.interactive-stat .stat-label {
  font-size: var(--font-size-xs);
  color: #64748b;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  display: block;
  margin-bottom: 2px;
}

.interactive-stat .stat-value {
  font-family: var(--font-mono);
  font-size: var(--font-size-base);
  font-weight: 600;
  color: #f8fafc;
}

.interactive-stat .stat-value.highlight {
  color: #fbbf24;
}

.interactive-stat .stat-value.success {
  color: #22c55e;
}

.interactive-buttons {
  display: flex;
  justify-content: center;
  gap: var(--spacing-2);
  flex-wrap: wrap;
  margin-top: var(--spacing-4);
}

.interactive-buttons .btn {
  font-size: var(--font-size-sm);
  padding: var(--spacing-2) var(--spacing-4);
}

.interactive-hint {
  text-align: center;
  font-size: var(--font-size-xs);
  color: #64748b;
  margin-top: var(--spacing-3);
  font-style: italic;
}

/* Class toggle buttons for Decision Boundary */
.class-toggle {
  display: flex;
  gap: var(--spacing-2);
}

.class-btn {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  padding: var(--spacing-2) var(--spacing-3);
  background: rgba(30, 41, 59, 0.8);
  border: 2px solid rgba(100, 116, 139, 0.4);
  border-radius: var(--radius-md);
  color: #94a3b8;
  font-size: var(--font-size-sm);
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
}

.class-btn:hover {
  border-color: rgba(148, 163, 184, 0.6);
}

.class-btn.active.class-a {
  border-color: #3b82f6;
  background: rgba(59, 130, 246, 0.2);
  color: #60a5fa;
}

.class-btn.active.class-b {
  border-color: #f97316;
  background: rgba(249, 115, 22, 0.2);
  color: #fb923c;
}

.class-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}

.class-a-dot {
  background: #3b82f6;
}

.class-b-dot {
  background: #f97316;
}

/* Responsive adjustments for about interactives */
@media (max-width: 480px) {
  .interactives-grid {
    grid-template-columns: 1fr;
  }

  .interactive-card {
    padding: var(--spacing-4);
  }

  .control-row {
    flex-direction: column;
    align-items: stretch;
  }

  .control-group {
    min-width: 100%;
  }

  .interactive-stats {
    gap: var(--spacing-2);
  }

  .interactive-stat {
    min-width: 60px;
  }
}

/* ===================================
   SKILL TREE VISUALIZATION
   =================================== */

/* Reduce spacing on skills page */
.page-header + .section.section-alt {
  padding-top: var(--spacing-8);
}

.section.section-alt + .section {
  padding-top: var(--spacing-4);
}

.skill-tree-container {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: var(--spacing-6);
  background: linear-gradient(135deg, rgba(15, 23, 42, 0.95) 0%, rgba(30, 41, 59, 0.95) 100%);
  border: 1px solid rgba(102, 126, 234, 0.3);
  border-radius: 16px;
  padding: var(--spacing-5);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.skill-tree-canvas-wrapper {
  position: relative;
  border-radius: 12px;
  overflow: hidden;
}

.skill-tree-canvas-wrapper canvas {
  display: block;
  width: 100%;
  border-radius: 12px;
}

.skill-info-panel {
  background: rgba(30, 41, 59, 0.8);
  border: 1px solid rgba(71, 85, 105, 0.5);
  border-radius: 12px;
  padding: var(--spacing-5);
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-height: 200px;
  transition: all 0.3s ease;
}

.skill-info-placeholder {
  color: #64748b;
  text-align: center;
  font-size: var(--font-size-sm);
  font-style: italic;
}

.skill-info-header {
  border-left: 3px solid;
  padding-left: var(--spacing-4);
  margin-bottom: var(--spacing-4);
}

.skill-info-category {
  font-size: var(--font-size-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.skill-info-name {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: #f8fafc;
  margin-top: var(--spacing-1);
}

.skill-info-description {
  color: #94a3b8;
  font-size: var(--font-size-sm);
  line-height: 1.6;
  margin-bottom: var(--spacing-4);
}

.skill-info-proficiency {
  margin-bottom: var(--spacing-4);
}

.skill-info-label {
  display: block;
  font-size: var(--font-size-xs);
  color: #64748b;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--spacing-2);
}

.skill-info-bar {
  height: 8px;
  background: rgba(51, 65, 85, 0.5);
  border-radius: 4px;
  overflow: hidden;
  margin-bottom: var(--spacing-1);
}

.skill-info-fill {
  height: 100%;
  border-radius: 4px;
  transition: width 0.5s ease;
}

.skill-info-value {
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  color: #f8fafc;
  font-weight: 600;
}

.skill-info-connections {
  margin-top: var(--spacing-2);
}

.skill-info-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-2);
  margin-top: var(--spacing-2);
}

.skill-tag {
  font-size: var(--font-size-xs);
  padding: var(--spacing-1) var(--spacing-2);
  background: rgba(51, 65, 85, 0.5);
  border: 1px solid;
  border-radius: 4px;
  color: #94a3b8;
}

.skill-tree-hint {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-2);
  margin-top: var(--spacing-4);
  font-size: var(--font-size-sm);
  color: var(--color-text-tertiary);
}

.skill-tree-hint svg {
  width: 16px;
  height: 16px;
  color: var(--color-primary-400);
}

/* Responsive skill tree */
@media (max-width: 900px) {
  .skill-tree-container {
    grid-template-columns: 1fr;
  }

  .skill-info-panel {
    min-height: auto;
    padding: var(--spacing-4);
  }

  .skill-info-placeholder {
    padding: var(--spacing-4) 0;
  }
}

@media (max-width: 480px) {
  .skill-tree-container {
    padding: var(--spacing-4);
  }

  .skill-tree-canvas-wrapper canvas {
    height: 400px;
  }
}