/* ---------- Tokens (vibecoder palette) ---------- */
:root{
  --bg:#0f1116;
  --panel:#171b23;
  --panel-2:#141821;
  --border:#2a3140;
  --text:#ecf0f7;
  --muted:#b1b7c6;
  --brand:#7dd3fc;      /* cyan */
  --brand-2:#c084fc;    /* purple */
  --shadow:0 12px 32px rgba(0,0,0,.38);
  --radius:16px;
  --radius-sm:12px;
  --maxw:1040px;
  --trans:180ms ease;
}

/* ---------- Base / Typography ---------- */
*{box-sizing:border-box}
html,body{margin:0}
html{scroll-behavior:smooth}
body{
  font-family: Inter, system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  font-size: clamp(15.5px, .95vw, 17px);
  line-height: 1.68;
  letter-spacing: .15px;
  background: var(--bg);
  color: var(--text);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
img{max-width:100%;display:block}
a{color:var(--brand);text-decoration:none;transition:color var(--trans), opacity var(--trans)}
a:hover{color:var(--brand-2)}
.container{max-width:var(--maxw);margin:0 auto;padding:0 20px}

h1,h2,h3{
  margin: 0 0 .55rem;
  line-height: 1.22;
  letter-spacing: -.01em;
  color:#f6f8ff;
  font-family: "Space Grotesk", Inter, sans-serif;
}
h1{font-weight:700;font-size:clamp(28px, 3.8vw, 44px)} /* bir tık küçültüldü */
h2{font-weight:700;font-size:clamp(20px, 2.2vw, 28px)}
h3{font-weight:600;font-size:clamp(16px, 1.5vw, 20px)}
p{margin:.5rem 0 1.1rem}
.card p{font-size: .98em}

/* ikinci başlık (hero alt satır) */
.subtitle{
  margin-top:-2px;
  color:var(--muted);
  font-size:clamp(15px, 1.1vw, 18px);
  font-weight:500;
}

/* ---------- Nav ---------- */
.nav{
  position:sticky;top:0;z-index:20;
  backdrop-filter:saturate(140%) blur(10px);
  background:rgba(15,17,22,.72);
  border-bottom:1px solid var(--border);
  box-shadow:0 6px 20px rgba(0,0,0,.35);
}
.nav-inner{
  display:flex;justify-content:space-between;align-items:center;
  padding:12px 0;
}
.brand a{
  display:inline-block;font-weight:800;
  background:linear-gradient(90deg,var(--brand),var(--brand-2));
  -webkit-background-clip:text;background-clip:text;color:transparent;
  font-size: clamp(20px, 2.2vw, 26px);
  padding:4px 8px;border-radius:10px;
  transition:transform var(--trans), opacity var(--trans);
}
.brand a:hover{transform:translateY(-1px);opacity:.96}
.nav a{margin-left:18px;color:#dfe4ef;opacity:.9;font-weight:500}
.nav a:hover{opacity:1}
.nav a.active{position:relative;opacity:1 !important;color:#fff}
.nav a.active::after{
  content:"";position:absolute;left:0;right:0;bottom:-6px;height:2px;border-radius:2px;
  background:linear-gradient(90deg,var(--brand),var(--brand-2));
}

/* ---------- Hero ---------- */
.hero{
  padding:64px 0 28px;
  background:
    radial-gradient(1100px 380px at 10% -10%,rgba(125,211,252,.18),transparent 55%),
    radial-gradient(1100px 380px at 90% -10%,rgba(192,132,252,.16),transparent 55%);
}

/* ---------- Cards & Grid ---------- */
.card{
  background:var(--panel);
  border:1px solid var(--border);
  border-radius:var(--radius);
  box-shadow:var(--shadow);
  padding:22px;
  margin:18px 0;
  transition:transform var(--trans), box-shadow var(--trans), border-color var(--trans);
}
.card:hover{
  transform:translateY(-2px);
  box-shadow:0 18px 40px rgba(0,0,0,.42);
  border-color:#343d51;
}
.grid{
  display:grid;gap:18px;margin-top:8px;
  grid-template-columns:repeat(auto-fit,minmax(280px,1fr));
}

/* ---------- About Section with Photo ---------- */
.about-content {
  display: flex;
  gap: 20px;
  align-items: flex-start;
}

.about-photo {
  flex-shrink: 0;
  width: 100px;
}

.profile-photo {
  width: 100px;
  height: 100px;
  object-fit: cover;
  border-radius: var(--radius-sm);
  border: 2px solid var(--border);
  box-shadow: var(--shadow);
  transition: transform var(--trans), box-shadow var(--trans);
}

.profile-photo:hover {
  transform: translateY(-2px);
  box-shadow: 0 18px 40px rgba(0,0,0,.42);
}

.about-text {
  flex: 1;
}

/* ---------- Tags ---------- */
.tags span{
  display:inline-block;margin:4px 6px 0 0;padding:6px 12px;border-radius:999px;
  font-size:.82rem;font-weight:600;color:#0b1220;
  background:linear-gradient(90deg,#a5f3fc,#d8b4fe);
  border:1px solid rgba(255,255,255,.25);
}

/* ---------- Buttons ---------- */
.btn{
  display:inline-block;padding:10px 16px;border-radius:12px;
  border:1px solid var(--border);background:var(--panel);color:var(--text);
  box-shadow:var(--shadow);font-weight:650;font-size:.95rem;
  transition:transform var(--trans), opacity var(--trans), box-shadow var(--trans);
}
.btn:hover{transform:translateY(-1px);opacity:.96}
.btn.primary{border:none;color:#0f1116;background:linear-gradient(90deg,var(--brand),var(--brand-2))}
.btn:active{transform:translateY(0)}

/* ---------- Footer ---------- */
.footer{border-top:1px solid var(--border);margin-top:28px;color:var(--muted)}
.footer .container{padding:24px 20px;text-align:center;font-size:.95rem}

/* ---------- Anchor comfort ---------- */
#contact{scroll-margin-top:84px}

/* ---------- Accessibility ---------- */
:focus{outline:none}
:focus-visible{outline:2px solid var(--brand);outline-offset:3px;border-radius:8px}

/* ---------- Responsive ---------- */
@media (max-width:860px){
  .nav a{margin-left:14px}
  .hero{padding:48px 0 22px}
}

@media (max-width:640px) {
  .about-content {
    flex-direction: column;
    align-items: center;
    gap: 16px;
  }
  
  .about-photo {
    order: -1;
    width: 85px;
  }
  
  .profile-photo {
    width: 85px;
    height: 85px;
  }
}

@media (max-width:520px){
  .btn{width:100%;text-align:center;margin:8px 0}
  .container{padding:0 16px}
}

/* ========== Professional Academic Extensions ========== */

/* Skip link for accessibility */
.skip-link {
  position: absolute;
  top: -40px;
  left: 6px;
  background: var(--brand);
  color: #0f1116;
  padding: 8px 12px;
  text-decoration: none;
  border-radius: 8px;
  z-index: 1000;
  font-weight: 600;
}

.skip-link:focus {
  top: 6px;
}

/* Enhanced Navigation */
.nav-mobile {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: var(--panel);
  border-top: 1px solid var(--border);
  padding: 1rem;
  box-shadow: var(--shadow);
}

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

.nav-mobile .nav-link {
  display: block;
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--border);
  color: var(--text);
  opacity: 0.9;
}

.nav-mobile .nav-link:last-child {
  border-bottom: none;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--text);
  cursor: pointer;
}

/* Enhanced Grid System */
.grid-2 {
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
}

.grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.grid-4 {
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

/* Section Headers */
.section {
  padding: 4rem 0;
}

.section-header {
  text-align: center;
  margin-bottom: 3rem;
}

.section-header h2 {
  margin-bottom: 0.5rem;
}

.lead {
  font-size: 1.125rem;
  color: var(--muted);
  margin-bottom: 2rem;
}

/* Enhanced Buttons */
.btn-primary {
  background: linear-gradient(90deg, var(--brand), var(--brand-2));
  color: #0f1116;
  border: none;
}

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

.btn-secondary:hover {
  border-color: var(--brand);
  color: var(--brand);
}

.btn-ghost {
  background: transparent;
  color: var(--brand);
  border: 1px solid var(--brand);
}

.btn-ghost:hover {
  background: var(--brand);
  color: #0f1116;
}

/* Publication Styles */
.publication {
  padding: 1.5rem 0;
  border-bottom: 1px solid var(--border);
}

.publication:last-child {
  border-bottom: none;
}

.publication-title {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text);
}

.publication-authors {
  color: var(--muted);
  margin-bottom: 0.5rem;
}

.publication-venue {
  font-style: italic;
  color: var(--muted);
  margin-bottom: 1rem;
}

.publication-links {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-top: 1rem;
}

/* Badge System */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.25rem 0.75rem;
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: 999px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.badge-success {
  background: #10b981;
  color: white;
}

.badge-warning {
  background: #f59e0b;
  color: white;
}

.badge-info {
  background: var(--brand);
  color: #0f1116;
}

/* Timeline */
.timeline {
  position: relative;
  padding-left: 2rem;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0.5rem;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--border);
}

.timeline-item {
  position: relative;
  padding-bottom: 2rem;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -1.75rem;
  top: 0.25rem;
  width: 12px;
  height: 12px;
  background: var(--brand);
  border-radius: 50%;
  border: 3px solid var(--bg);
}

.timeline-date {
  font-size: 0.875rem;
  color: var(--muted);
  font-weight: 500;
}

.timeline-title {
  font-weight: 600;
  margin: 0.25rem 0 0.5rem 0;
  color: var(--text);
}

.timeline-description {
  color: var(--muted);
  margin: 0;
}

/* Blog Cards */
.blog-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: all var(--trans);
}

.blog-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 18px 40px rgba(0,0,0,.42);
  border-color: var(--brand);
}

.blog-card-image {
  width: 100%;
  height: 200px;
  object-fit: cover;
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  display: flex;
  align-items: center;
  justify-content: center;
  color: #0f1116;
  font-size: 3rem;
}

.blog-card-content {
  padding: 1.5rem;
}

.blog-card-date {
  font-size: 0.875rem;
  color: var(--muted);
  margin-bottom: 0.5rem;
}

.blog-card-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  color: var(--text);
}

.blog-card-excerpt {
  color: var(--muted);
  margin-bottom: 1rem;
}

/* Social Links */
.social-links {
  display: flex;
  gap: 1rem;
  justify-content: center;
}

.social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 50%;
  color: var(--muted);
  transition: all var(--trans);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.875rem;
}

.social-link:hover {
  background: var(--brand);
  border-color: var(--brand);
  color: #0f1116;
  transform: translateY(-2px);
}

/* Contact Grid */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: start;
}

.contact-info {
  background: var(--panel);
  padding: 2rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.contact-icon {
  width: 2rem;
  height: 2rem;
  background: var(--brand);
  color: #0f1116;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.875rem;
  font-weight: 600;
}

/* Enhanced Footer */
.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer-section h4 {
  margin-bottom: 1rem;
  color: var(--text);
  font-family: "Space Grotesk", Inter, sans-serif;
}

.footer-links {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-links li {
  margin-bottom: 0.5rem;
}

.footer-links a {
  color: var(--muted);
  transition: color var(--trans);
}

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

.footer-bottom {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.875rem;
}

/* CV Embed */
.cv-embed {
  width: 100%;
  height: 80vh;
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

/* Theme Toggle */
.theme-toggle {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 1rem;
  width: 1.5rem;
  height: 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text);
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  margin: 0 10px 0 0;
  position: relative;
  overflow: hidden;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.theme-toggle:hover {
  background: var(--brand);
  border-color: var(--brand);
  color: #0f1116;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(125, 211, 252, 0.3);
}

.theme-toggle:active {
  transform: translateY(0);
  transition-duration: 0.1s;
}

#theme-icon {
  font-size: 0.75rem;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  display: inline-block;
}

#theme-icon svg{
  width:10px;
  height:10px;
  display:block;
}

.theme-toggle:hover #theme-icon {
  transform: rotate(180deg);
}

/* Enhanced theme toggle with sliding background */
.theme-toggle::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  border-radius: 50%;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  transform: translate(-50%, -50%);
  z-index: -1;
}

.theme-toggle:hover::before {
  width: 100%;
  height: 100%;
}

/* Dark Mode Support */
[data-theme="dark"] {
  --bg: #0f1116;
  --panel: #171b23;
  --border: #2a3140;
  --text: #ecf0f7;
  --muted: #b1b7c6;
  --brand: #7dd3fc;
  --brand-2: #c084fc;
}

[data-theme="light"] {
  --bg: #fafbfc;
  --panel: #ffffff;
  --border: #e2e5e9;
  --text: #1f2937;
  --muted: #6b7280;
  --brand: #4f46e5;
  --brand-2: #7c3aed;
}

/* Responsive Enhancements */
@media (max-width: 768px) {
  .nav a:not(.brand a) {
    display: none;
  }
  
  .nav-toggle {
    display: block;
  }
  
  .contact-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  
  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }
  
  .timeline {
    padding-left: 1.5rem;
  }
  
  .timeline-item::before {
    left: -1.25rem;
  }
  
  .hero {
    padding: 48px 0 32px;
  }
  
  .section {
    padding: 3rem 0;
  }
}

/* Print Styles */
@media print {
  .nav,
  .theme-toggle,
  .footer {
    display: none;
  }
  
  .hero {
    background: none;
    padding: 2rem 0;
  }
  
  .card {
    break-inside: avoid;
    box-shadow: none;
    border: 1px solid #ddd;
  }
  
  a {
    color: inherit;
    text-decoration: underline;
  }
  
  .btn {
    display: none;
  }
}

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

/* Focus indicators */
.nav a:focus-visible,
.btn:focus-visible,
.social-link:focus-visible,
.theme-toggle:focus-visible {
  outline: 2px solid var(--brand);
  outline-offset: 2px;
}

/* Performance optimizations */
.card,
.blog-card {
  will-change: transform;
}

/* Loading states */
.loading {
  opacity: 0.6;
  pointer-events: none;
}

.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}