:root{
  --bg:#0c0f14;
  --panel:#10151f;          /* slightly lighter for contrast */
  --card:#161b25;
  --text:#f2f6fb;           /* brighter text for readability */
  --muted:#b6c0cf;          /* brighter muted text */
  --border:#3a4560;         /* lighter borders for contrast */
  --link:#61a6ff;
  --accent:#2ea043;
  --warn:#d29922;
  
  /* Enhanced color palette */
  --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  --gradient-accent: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
  --gradient-dark: linear-gradient(135deg, #0c0f14 0%, #1a1d29 100%);
  
  /* Shadows and effects */
  --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.15);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.2);
  --shadow-xl: 0 16px 48px rgba(0,0,0,0.3);
  
  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{
  font-family: 'Inter', ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, Noto Sans, Helvetica, Arial;
  background: var(--gradient-dark);
  color: var(--text);
  line-height: 1.65;
  -webkit-text-size-adjust: 100%;
  transition: background var(--transition-normal), color var(--transition-normal);
  min-height: 100vh;
  position: relative;
}

/* Animated background particles */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: 
    radial-gradient(circle at 20% 80%, rgba(120, 119, 198, 0.3) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(255, 119, 198, 0.3) 0%, transparent 50%),
    radial-gradient(circle at 40% 40%, rgba(120, 219, 255, 0.2) 0%, transparent 50%);
  animation: backgroundShift 20s ease-in-out infinite;
  z-index: -1;
}

@keyframes backgroundShift {
  0%, 100% { opacity: 0.3; transform: scale(1); }
  50% { opacity: 0.6; transform: scale(1.1); }
}

/* Typography */
h1,h2,h3{color:var(--text);margin:0 0 8px 0}
.lead{color:var(--muted);max-width:65ch}

/* Layout */
.container{width:min(1100px,92%);margin:0 auto}
.section{padding:56px 0;border-top:1px solid var(--border)}
.section-head{display:flex;gap:12px;align-items:baseline;justify-content:space-between;flex-wrap:wrap;margin-bottom:12px}
.muted{color:var(--muted)}
.empty,.error{text-align:center;color:var(--muted);padding:24px 0}
.justified-text{text-align:justify}

/* Header / Nav */
.site-header{
  position:sticky;top:0;z-index:100;
  background:rgba(12,15,20,.9);backdrop-filter:blur(12px);
  border-bottom:1px solid var(--border);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
}
.nav-row{display:flex;align-items:center;gap:16px;padding:16px 0}
.brand{
  color:var(--text);text-decoration:none;font-weight:700;font-size:1.1rem;
  letter-spacing:.3px;background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  transition: all var(--transition-normal);
}
.brand:hover {
  transform: scale(1.05);
}
.nav{margin-left:auto;display:flex;gap:20px;align-items:center}
.nav a{
  color:var(--text);text-decoration:none;opacity:.9;
  padding:8px 12px;border-radius:8px;transition: all var(--transition-fast);
  position: relative;
}
.nav a:hover{
  color:var(--link);opacity:1;background:rgba(97,166,255,0.1);
  transform: translateY(-1px);
}
.nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background: var(--gradient-accent);
  transition: all var(--transition-fast);
  transform: translateX(-50%);
}
.nav a:hover::after {
  width: 80%;
}

/* Theme Toggle */
.theme-toggle {
  background: var(--card);
  border: 1px solid var(--border);
  color: var(--text);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
  margin: 0 8px;
}
.theme-toggle:hover {
  background: var(--link);
  color: white;
  transform: scale(1.1) rotate(180deg);
  box-shadow: var(--shadow-md);
}

.btn{
  display:inline-block;background:var(--gradient-primary);color:white;text-decoration:none;
  padding:12px 18px;border-radius:12px;font-weight:600;border:none;cursor:pointer;
  transition: all var(--transition-fast);box-shadow: var(--shadow-sm);
  position: relative;overflow: hidden;
}
.btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
  transition: left var(--transition-normal);
}
.btn:hover::before {
  left: 100%;
}
.btn:hover{
  transform: translateY(-2px);box-shadow: var(--shadow-lg);
}
.btn--ghost{
  background:transparent;color:var(--text);border:1px solid var(--border);
  backdrop-filter: blur(10px);
}
.btn--ghost:hover {
  background: var(--card);
  border-color: var(--link);
  color: var(--link);
}
.btn--sm{padding:10px 14px;font-size:.9rem}

.hamburger{display:none;cursor:pointer;padding:8px}
.hamburger span{
  display:block;width:24px;height:2px;background:var(--text);
  margin:4px 0;border-radius:2px;transition: all var(--transition-fast);
}
.hamburger:hover span {
  background: var(--link);
}
.nav-toggle{display:none}

@media (max-width:900px){
  .hamburger{display:block;margin-left:auto}
  .nav{
    position:absolute;left:0;right:0;top:100%;
    background:var(--panel);border-bottom:1px solid var(--border);
    flex-direction:column;align-items:flex-start;gap:0;padding:8px 4%;
    max-height:0;overflow:hidden;transition:max-height .2s ease
  }
  .nav a{padding:10px 8px;width:100%}
  .nav-toggle:checked ~ .hamburger + .nav{max-height:360px}
}

/* Hero */
.hero{
  display:grid;grid-template-columns:1.4fr 1fr;gap:40px;padding:60px 0;
  position: relative;
}
.hero__text h1{
  margin:0 0 16px 0;font-size:2.5rem;font-weight:700;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.2;
}
.hero__text p.lead {
  font-size: 1.1rem;line-height: 1.6;margin-bottom: 24px;
}
.cta-row{display:flex;gap:16px;margin-top:24px;flex-wrap:wrap}
.hero__avatar{
  display:flex;justify-content:center;align-items:center;
  position: relative;
}
.hero__avatar::before {
  content: '';
  position: absolute;
  width: 180px;
  height: 180px;
  border-radius: 50%;
  background: var(--gradient-accent);
  opacity: 0.3;
  animation: pulse 3s ease-in-out infinite;
}
.hero__avatar img{
  width:160px;height:160px;border-radius:50%;
  border:3px solid var(--border);object-fit:cover;
  position: relative;z-index: 1;
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-lg);
}
.hero__avatar img:hover {
  transform: scale(1.05);
  border-color: var(--link);
}

@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 0.3; }
  50% { transform: scale(1.1); opacity: 0.5; }
}

@media (max-width:900px){
  .hero{grid-template-columns:1fr;gap:32px;padding:40px 0}
  .hero__avatar{order:-1;margin-bottom:16px}
  .hero__text h1{font-size:2rem}
}
@media (max-width:640px){
  .hero__text h1{font-size:1.8rem}
  .cta-row{justify-content:center}
}

/* Cards / Grid */
.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.grid.grid--2{grid-template-columns:repeat(2,1fr)}
@media (max-width:1000px){.grid{grid-template-columns:repeat(2,1fr)}}
@media (max-width:640px){.grid,.grid.grid--2{grid-template-columns:1fr}}

.card{
  background:var(--card);border:1px solid var(--border);
  border-radius:16px;padding:20px;display:flex;flex-direction:column;gap:12px;
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-sm);
}
.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-accent);
  transform: scaleX(0);
  transition: transform var(--transition-normal);
}
.card:hover::before {
  transform: scaleX(1);
}
.card:hover{
  border-color:var(--link);transform:translateY(-4px);
  box-shadow: var(--shadow-lg);
  background: rgba(22, 27, 37, 0.8);
}
.card__head{display:flex;align-items:baseline;justify-content:space-between;gap:10px;flex-wrap:wrap}
.card__links{display:flex;gap:12px;flex-wrap:wrap}
.link{color:var(--text);text-decoration:none}
.link:hover{color:var(--link)}
.tags{display:flex;gap:8px;flex-wrap:wrap}
.tag{font-size:.75rem;padding:4px 8px;border-radius:999px;border:1px solid var(--border);color:var(--muted)}

/* Lists */
.bullets{padding-left:18px;margin:8px 0}
.bullets li{margin:6px 0;color:var(--text)}  /* ensure bullets not too dim */

/* About Navigation */
section#about .about-nav {
  margin-top: 32px !important;
  padding-top: 24px !important;
  border-top: 1px solid var(--border) !important;
  display: block !important;
  visibility: visible !important;
  background: rgba(255, 0, 0, 0.1) !important; /* Debug: temporary red background */
}
section#about .about-nav h3 {
  margin-bottom: 16px !important;
  color: var(--text) !important;
  font-size: 1.2rem !important;
  font-weight: 600 !important;
  display: block !important;
}
section#about .about-nav-links {
  display: grid !important;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)) !important;
  gap: 12px !important;
  margin-top: 16px !important;
  visibility: visible !important;
}
section#about .about-nav-link {
  display: flex !important;
  align-items: center !important;
  gap: 8px !important;
  padding: 12px 16px !important;
  background: var(--card) !important;
  border: 1px solid var(--border) !important;
  border-radius: 10px !important;
  color: var(--text) !important;
  text-decoration: none !important;
  transition: all var(--transition-fast) !important;
  font-size: 0.9rem !important;
  font-weight: 500 !important;
  visibility: visible !important;
  opacity: 1 !important;
}
section#about .about-nav-link:hover {
  background: var(--link) !important;
  color: white !important;
  border-color: var(--link) !important;
  transform: translateY(-2px) !important;
  box-shadow: var(--shadow-md) !important;
}
section#about .about-nav-link i {
  font-size: 1rem !important;
  width: 16px !important;
  text-align: center !important;
  display: inline-block !important;
}
section#about .about-nav-link span {
  flex: 1 !important;
  display: inline-block !important;
}

/* Timeline */
.timeline{display:grid;gap:12px}
.item__title{font-weight:700}
.item__meta{color:var(--muted);font-size:.95rem}

/* Repo section */
.controls{
  display:flex;gap:10px;align-items:center;flex-wrap:wrap;margin-bottom:12px
}
.controls input[type="search"], .controls select{
  background:var(--panel);border:1px solid var(--border);color:var(--text);
  padding:10px 12px;border-radius:8px;outline:none
}
.check{color:var(--muted);display:flex;align-items:center;gap:6px}
.repo-card .top{display:flex;gap:8px;align-items:baseline;flex-wrap:wrap}
.repo-card h4{margin:0}
.repo-card .desc{color:var(--text)}         /* improve contrast */
.repo-meta{display:flex;gap:10px;flex-wrap:wrap;color:var(--muted);font-size:.9rem}
.chip{font-size:.72rem;padding:2px 8px;border-radius:999px;border:1px solid var(--border);color:var(--muted)}
.chip.warn{color:var(--warn);border-color:#5a4722}

/* Downloads row */
.downloads{display:flex;gap:12px;flex-wrap:wrap;margin-top:12px}

/* Contact form — increased contrast and visibility on mobile */
.contact-form{display:flex;flex-direction:column;gap:12px;max-width:720px}
.form-row{display:flex;gap:12px;flex-wrap:wrap}
.contact-form input[type="text"],
.contact-form input[type="email"],
.contact-form textarea{
  width:100%;
  background:#0f1420;                /* higher contrast than --panel */
  border:1.5px solid var(--border);
  color:var(--text);
  padding:12px 14px;
  border-radius:10px;
  outline:none;
  caret-color:var(--link);
}
.form-row input{flex:1 1 260px}

/* Visible placeholders across mobile browsers */
.contact-form input::placeholder,
.contact-form textarea::placeholder{color:#c7d1df;opacity:1}
.contact-form input::-webkit-input-placeholder,
.contact-form textarea::-webkit-input-placeholder{color:#c7d1df;opacity:1}
.contact-form input:-ms-input-placeholder,
.contact-form textarea:-ms-input-placeholder{color:#c7d1df}

/* Focus ring for accessibility */
.contact-form input:focus,
.contact-form textarea:focus{
  border-color:#77b5ff;
  box-shadow:0 0 0 3px rgba(97,166,255,.25);
}

/* Make autofill text readable on dark background */
input:-webkit-autofill,
textarea:-webkit-autofill{
  -webkit-text-fill-color: var(--text) !important;
  transition: background-color 5000s ease-in-out 0s;
}

/* Button alignment */
.contact-form button{align-self:flex-start}

/* Footer */
.site-footer{border-top:1px solid var(--border);padding:28px 0;margin-top:24px;text-align:center;color:var(--muted)}

/* Research metrics (KNU-like cards) */
.metrics-grid{
  display:grid;
  grid-template-columns:repeat(3,1fr);
  gap:16px;
  margin-bottom:12px;
}
@media (max-width:900px){.metrics-grid{grid-template-columns:1fr 1fr}}
@media (max-width:560px){.metrics-grid{grid-template-columns:1fr}}
.metric-card{
  background:var(--card);
  border:1px solid var(--border);
  border-radius:12px;
  padding:22px 16px;
  text-align:center;
}
.metric-value{
  font-size:2.2rem;
  font-weight:800;
  line-height:1.1;
}
.metric-label{
  color:var(--muted);
  margin-top:6px;
  font-size:0.98rem;
}
.knu-metrics .metric-card{border-color:#2a3a57}

/* Research actions */
.stats-actions{display:flex;gap:12px;align-items:center;flex-wrap:wrap}

/* Cite overlay */
.overlay{
  position:fixed;inset:0;
  background:rgba(6,10,16,.6);
  backdrop-filter:blur(2px);
  display:flex;align-items:center;justify-content:center;
}
.overlay[hidden]{display:none !important;}
.overlay__panel{
  width:min(900px,92%);
  background:var(--panel);
  border:1px solid var(--border);
  border-radius:12px;
  padding:16px;
  box-shadow:0 10px 30px rgba(0,0,0,.4);
}
.overlay__head{
  display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:12px
}
.icon-btn{
  background:transparent;border:1px solid var(--border);color:var(--text);
  width:32px;height:32px;border-radius:8px;cursor:pointer;line-height:28px;text-align:center;font-size:18px
}
.cite-grid{display:grid;gap:12px;grid-template-columns:1fr}
.cite-card{
  background:var(--card);border:1px solid var(--border);border-radius:10px;padding:12px
}
.cite-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:8px}
.copy-btn{
  background:transparent;border:1px solid var(--border);color:var(--text);
  padding:6px 10px;border-radius:8px;cursor:pointer
}
.cite-text{margin:0;white-space:pre-wrap;word-break:break-word;background:transparent;color:var(--text)}

/* Full-width Skills section with icons */
.skills-section{
  padding:56px 0;
  background:var(--panel);
  border-top:1px solid var(--border);
  border-bottom:1px solid var(--border);
}
.skills-section h2{ text-align:center;margin:0 0 20px 0 }
.skills-grid{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(260px,1fr));
  gap:16px;
  width:min(1400px,96%);
  margin:0 auto;
}
.skill-card{
  display:flex;gap:14px;align-items:flex-start;
  background:var(--card);border:1px solid var(--border);
  border-radius:14px;padding:18px;
  transition:border-color .15s ease, transform .05s ease;
}
.skill-card:hover{border-color:#4a6aa0;transform:translateY(-1px)}
.skill-card i{font-size:1.4rem;color:var(--link);line-height:1;margin-top:2px;flex:0 0 auto}
.skill-card h3{margin:0 0 6px 0;font-size:1.05rem}
.skill-card p{margin:0;color:var(--muted)}

/* Social Sharing */
.social-share {
  margin-top: 20px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
}
.share-label {
  color: var(--muted);
  font-size: 0.9rem;
  margin-right: 12px;
}
.share-buttons {
  display: flex;
  gap: 8px;
  margin-top: 8px;
}
.share-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--text);
  text-decoration: none;
  transition: all 0.2s ease;
}
.share-btn:hover {
  transform: translateY(-1px);
  border-color: var(--link);
  color: var(--link);
}
.share-btn.linkedin:hover { background: #0077b5; color: white; border-color: #0077b5; }
.share-btn.twitter:hover { background: #1da1f2; color: white; border-color: #1da1f2; }
.share-btn.facebook:hover { background: #1877f2; color: white; border-color: #1877f2; }
.share-btn.copy-url:hover { background: var(--accent); color: white; border-color: var(--accent); }

/* Enhanced Project Cards */
.project-card {
  position: relative;
  overflow: hidden;
}
.project-stats {
  display: flex;
  gap: 12px;
  margin: 8px 0;
  flex-wrap: wrap;
}
.stat {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 0.85rem;
  color: var(--muted);
}
.stat i {
  color: var(--link);
  font-size: 0.9rem;
}
.project-card .card__links {
  margin-top: auto;
  padding-top: 8px;
}
.project-card .btn {
  display: flex;
  align-items: center;
  gap: 6px;
}

/* Enhanced Contact Form */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: 40px;
  margin-top: 24px;
}
@media (max-width: 900px) {
  .contact-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
}

.contact-info h3 {
  margin-bottom: 16px;
  color: var(--text);
}
.contact-methods {
  margin-bottom: 24px;
}
.contact-method {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
  padding: 12px;
  background: var(--card);
  border-radius: 8px;
  border: 1px solid var(--border);
}
.contact-method i {
  color: var(--link);
  font-size: 1.2rem;
  width: 20px;
  text-align: center;
}
.contact-method strong {
  display: block;
  margin-bottom: 2px;
  color: var(--text);
}
.contact-method p {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.social-links h4 {
  margin-bottom: 12px;
  color: var(--text);
  font-size: 1rem;
}
.social-buttons {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}
.social-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  text-decoration: none;
  font-size: 0.9rem;
  transition: all 0.2s ease;
}
.social-btn:hover {
  transform: translateY(-1px);
  border-color: var(--link);
  color: var(--link);
}
.social-btn.github:hover { background: #333; color: white; border-color: #333; }
.social-btn.linkedin:hover { background: #0077b5; color: white; border-color: #0077b5; }
.social-btn.researchgate:hover { background: #00d0aa; color: white; border-color: #00d0aa; }

/* Enhanced Form Styles */
.form-group {
  margin-bottom: 16px;
}
.form-group label {
  display: block;
  margin-bottom: 6px;
  color: var(--text);
  font-weight: 500;
  font-size: 0.9rem;
}
.contact-form select {
  width: 100%;
  background: var(--panel);
  border: 1.5px solid var(--border);
  color: var(--text);
  padding: 12px 14px;
  border-radius: 10px;
  outline: none;
  font-size: 1rem;
}
.contact-form select:focus {
  border-color: #77b5ff;
  box-shadow: 0 0 0 3px rgba(97,166,255,.25);
}
.char-count {
  text-align: right;
  font-size: 0.8rem;
  color: var(--muted);
  margin-top: 4px;
}
.form-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 16px;
}
.form-status {
  font-size: 0.9rem;
  padding: 8px 12px;
  border-radius: 6px;
  display: none;
}
.form-status.success {
  background: rgba(46, 160, 67, 0.1);
  color: var(--accent);
  border: 1px solid rgba(46, 160, 67, 0.3);
  display: block;
}
.form-status.error {
  background: rgba(210, 153, 34, 0.1);
  color: var(--warn);
  border: 1px solid rgba(210, 153, 34, 0.3);
  display: block;
}

/* Performance Optimizations */
img {
  max-width: 100%;
  height: auto;
}
.hero__avatar img {
  width: 160px;
  height: 160px;
  border-radius: 50%;
  border: 1px solid var(--border);
  object-fit: cover;
}

/* Loading States */
.loading {
  opacity: 0.6;
  pointer-events: none;
}
.loading::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 20px;
  height: 20px;
  margin: -10px 0 0 -10px;
  border: 2px solid var(--border);
  border-top-color: var(--link);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}
@keyframes spin {
  to { transform: rotate(360deg); }
}

/* Accessibility Improvements */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Focus indicators */
.btn:focus,
.share-btn:focus,
.social-btn:focus,
.contact-form input:focus,
.contact-form textarea:focus,
.contact-form select:focus {
  outline: 2px solid var(--link);
  outline-offset: 2px;
}

/* Demo Modal Styles */
.demo-body {
  padding: 16px 0;
}
.demo-content h4 {
  color: var(--text);
  margin: 16px 0 8px 0;
  font-size: 1.1rem;
}
.demo-content h4:first-child {
  margin-top: 0;
}
.demo-content ol,
.demo-content ul {
  margin: 8px 0;
  padding-left: 20px;
}
.demo-content li {
  margin: 4px 0;
  color: var(--text);
}
.demo-content p {
  margin: 8px 0;
  color: var(--text);
}
.demo-content strong {
  color: var(--link);
}

/* Scroll to top button */
.scroll-to-top {
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}
.scroll-to-top:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.4);
}

/* Enhanced Mobile & Tablet Optimizations */
@media (max-width: 1024px) {
  .container {
    width: min(1000px, 94%);
  }
  .hero {
    gap: 32px;
    padding: 48px 0;
  }
  .section {
    padding: 48px 0;
  }
}

@media (max-width: 768px) {
  .container {
    width: min(900px, 96%);
  }
  .hero {
    gap: 24px;
    padding: 40px 0;
  }
  .hero__text h1 {
    font-size: 2.2rem;
  }
  .section {
    padding: 40px 0;
  }
  .nav {
    gap: 16px;
  }
  .nav a {
    padding: 6px 10px;
    font-size: 0.95rem;
  }
  .theme-toggle {
    width: 36px;
    height: 36px;
  }
}

@media (max-width: 640px) {
  .container {
    width: min(100%, 98%);
    padding-left: 20px;
    padding-right: 20px;
  }
  .hero__text h1 {
    font-size: 1.9rem;
    line-height: 1.3;
  }
  .hero__text p.lead {
    font-size: 1rem;
  }
  .share-buttons {
    justify-content: center;
    margin-top: 12px;
  }
  .project-stats {
    justify-content: center;
    gap: 8px;
  }
  .social-buttons {
    justify-content: center;
    gap: 6px;
  }
  .form-row {
    flex-direction: column;
    gap: 16px;
  }
  .form-row input {
    flex: none;
  }
  .scroll-to-top {
    bottom: 15px;
    right: 15px;
    width: 45px;
    height: 45px;
  }
  .card {
    padding: 16px;
  }
  .btn {
    padding: 10px 16px;
    font-size: 0.95rem;
  }
  .btn--sm {
    padding: 8px 12px;
    font-size: 0.85rem;
  }
  section#about .about-nav-links {
    grid-template-columns: repeat(2, 1fr) !important;
    gap: 8px !important;
  }
  section#about .about-nav-link {
    padding: 10px 12px !important;
    font-size: 0.85rem !important;
  }
}

@media (max-width: 480px) {
  .container {
    padding-left: 20px;
    padding-right: 20px;
  }
  .hero__text h1 {
    font-size: 1.7rem;
  }
  .hero__avatar img {
    width: 140px;
    height: 140px;
  }
  .hero__avatar::before {
    width: 160px;
    height: 160px;
  }
  .nav {
    flex-direction: column;
    gap: 12px;
    padding: 12px 4%;
  }
  .nav a {
    padding: 10px 8px;
    width: 100%;
    text-align: center;
  }
  .theme-toggle {
    align-self: center;
    margin: 8px 0;
  }
}

/* Cross-browser compatibility */
@supports not (backdrop-filter: blur(10px)) {
  .site-header {
    background: rgba(12, 15, 20, 0.95);
  }
  .btn--ghost {
    background: rgba(22, 27, 37, 0.8);
  }
}

@supports not (display: grid) {
  .grid {
    display: flex;
    flex-wrap: wrap;
  }
  .grid > * {
    flex: 1 1 300px;
    margin: 8px;
  }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
  :root {
    --border: #ffffff;
    --text: #ffffff;
    --muted: #cccccc;
  }
  [data-theme="light"] {
    --border: #000000;
    --text: #000000;
    --muted: #333333;
  }
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  
  body::before {
    animation: none;
  }
  
  .hero__avatar::before {
    animation: none;
  }
}

/* Light mode theme */
[data-theme="light"] {
  --bg: #f8fafc;
  --panel: #ffffff;
  --card: #f1f5f9;
  --text: #1e293b;
  --muted: #64748b;
  --border: #e2e8f0;
  --link: #3b82f6;
  --accent: #10b981;
  --warn: #f59e0b;
  
  --gradient-primary: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
  --gradient-secondary: linear-gradient(135deg, #ec4899 0%, #be185d 100%);
  --gradient-accent: linear-gradient(135deg, #06b6d4 0%, #0891b2 100%);
  --gradient-dark: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
  
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.07);
  --shadow-lg: 0 10px 15px rgba(0,0,0,0.1);
  --shadow-xl: 0 20px 25px rgba(0,0,0,0.1);
}

[data-theme="light"] body {
  background: var(--gradient-dark);
}

[data-theme="light"] body::before {
  background: 
    radial-gradient(circle at 20% 80%, rgba(59, 130, 246, 0.1) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(236, 72, 153, 0.1) 0%, transparent 50%),
    radial-gradient(circle at 40% 40%, rgba(6, 182, 212, 0.08) 0%, transparent 50%);
}

[data-theme="light"] .site-header {
  background: rgba(248, 250, 252, 0.9);
  border-bottom-color: var(--border);
}

[data-theme="light"] .contact-form input[type="text"],
[data-theme="light"] .contact-form input[type="email"],
[data-theme="light"] .contact-form textarea,
[data-theme="light"] .contact-form select{
  background: #ffffff;
  border: 1.5px solid var(--border);
  color: var(--text);
}

[data-theme="light"] .contact-form input::placeholder,
[data-theme="light"] .contact-form textarea::placeholder{
  color: #94a3b8;
}

[data-theme="light"] .contact-method {
  background: #ffffff;
}

[data-theme="light"] .social-btn {
  background: #ffffff;
}

[data-theme="light"] .theme-toggle {
  background: var(--card);
  border-color: var(--border);
}

[data-theme="light"] section#about .about-nav-link {
  background: #ffffff !important;
  border-color: var(--border) !important;
}

/* Auto theme detection */
@media (prefers-color-scheme: light) {
  :root:not([data-theme]) {
    --bg: #f8fafc;
    --panel: #ffffff;
    --card: #f1f5f9;
    --text: #1e293b;
    --muted: #64748b;
    --border: #e2e8f0;
    --link: #3b82f6;
    --accent: #10b981;
    --warn: #f59e0b;
  }
}