/* ========================================
   Veysel Bozkurt — Academic Website
   Minimalist Design System
   ======================================== */

:root {
  --color-bg: #fafaf9;
  --color-bg-alt: #f5f5f4;
  --color-surface: #ffffff;
  --color-text: #1c1917;
  --color-text-secondary: #57534e;
  --color-text-muted: #a8a29e;
  --color-accent: #292524;
  --color-accent-light: #44403c;
  --color-border: #e7e5e4;
  --color-border-light: #f0efee;
  --color-link: #78716c;
  --font-serif: 'Playfair Display', Georgia, 'Times New Roman', serif;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --max-width: 960px;
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  --space-2xl: 4rem;
  --space-3xl: 6rem;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  border-bottom: 1px solid var(--color-border);
  transition: border-color 0.2s, color 0.2s;
}

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

img {
  max-width: 100%;
  display: block;
}

/* Container */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

/* ========================================
   Navigation
   ======================================== */

.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(250, 250, 249, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border-light);
  transition: box-shadow 0.3s;
}

.nav.scrolled {
  box-shadow: 0 1px 8px rgba(0, 0, 0, 0.04);
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav-name {
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--color-text);
  border: none;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: var(--space-lg);
  align-items: center;
}

.nav-links a {
  font-size: 0.78rem;
  font-weight: 400;
  color: var(--color-text-secondary);
  border: none;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  transition: color 0.2s;
}

.nav-links a:hover {
  color: var(--color-text);
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-sm);
  flex-direction: column;
  gap: 5px;
}

.nav-toggle span {
  display: block;
  width: 20px;
  height: 1.5px;
  background: var(--color-text);
  transition: transform 0.3s, opacity 0.3s;
}

/* Language Switcher */
.lang-switch a {
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  padding: 4px 12px;
  border: 1px solid var(--color-border) !important;
  border-radius: 100px;
  color: var(--color-text-secondary);
  transition: background 0.2s, color 0.2s;
}

.lang-switch a:hover {
  background: var(--color-accent);
  color: var(--color-bg);
  border-color: var(--color-accent) !important;
}

/* ========================================
   Hero
   ======================================== */

.hero {
  padding: calc(64px + var(--space-3xl)) 0 var(--space-2xl);
  border-bottom: 1px solid var(--color-border-light);
}

.hero-inner {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
}

.hero-photo {
  width: 180px;
  height: 180px;
  border-radius: 50%;
  object-fit: cover;
  object-position: center 20%;
  flex-shrink: 0;
  border: 3px solid var(--color-border);
}

.hero-content {
  flex: 1;
}

.hero-label {
  font-size: 0.75rem;
  font-weight: 400;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-sm);
}

.hero-title {
  font-family: var(--font-sans);
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 300;
  line-height: 1.1;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text);
  margin-bottom: var(--space-sm);
}

.hero-subtitle {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  font-weight: 300;
  margin-bottom: var(--space-lg);
}

.hero-fields {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.hero-fields span {
  font-size: 0.75rem;
  font-weight: 400;
  letter-spacing: 0.02em;
  padding: 5px 14px;
  border: 1px solid var(--color-border);
  border-radius: 100px;
  color: var(--color-text-secondary);
  background: var(--color-surface);
}

/* ========================================
   Sections
   ======================================== */

.section {
  padding: var(--space-2xl) 0;
}

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

.section-title {
  font-family: var(--font-serif);
  font-size: 1.6rem;
  font-weight: 400;
  letter-spacing: -0.01em;
  margin-bottom: var(--space-lg);
  color: var(--color-text);
}

/* ========================================
   About
   ======================================== */

.about-text-full p {
  color: var(--color-text-secondary);
  margin-bottom: var(--space-md);
  font-size: 0.92rem;
  line-height: 1.8;
}

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

/* ========================================
   Timeline (Positions)
   ======================================== */

.timeline {
  position: relative;
}

.timeline-item {
  display: flex;
  gap: var(--space-xl);
  padding-bottom: var(--space-md);
  border-bottom: 1px solid var(--color-border);
  margin-bottom: var(--space-md);
}

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

.timeline-year {
  font-size: 0.82rem;
  color: var(--color-text-muted);
  font-variant-numeric: tabular-nums;
  min-width: 7rem;
  flex-shrink: 0;
  padding-top: 2px;
}

.timeline-item strong {
  display: block;
  font-weight: 500;
  font-size: 0.92rem;
  margin-bottom: 2px;
}

.timeline-item p {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
}

/* ========================================
   Current Roles
   ======================================== */

.roles-list {
  list-style: none;
}

.roles-list li {
  padding: var(--space-sm) 0;
  padding-left: var(--space-md);
  border-left: 2px solid var(--color-border-light);
  margin-bottom: var(--space-sm);
  font-size: 0.92rem;
  color: var(--color-text-secondary);
  transition: border-color 0.2s;
}

.roles-list li:hover {
  border-left-color: var(--color-text-muted);
}

/* ========================================
   Publications
   ======================================== */

.pub-group {
  margin-bottom: var(--space-lg);
}

.pub-group-title {
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-md);
  padding-bottom: var(--space-sm);
  border-bottom: 1px solid var(--color-border);
}

.pub-list {
  list-style: none;
}

.pub-list li {
  font-size: 0.88rem;
  line-height: 1.65;
  color: var(--color-text-secondary);
  padding: var(--space-sm) 0;
  padding-left: var(--space-md);
  border-left: 2px solid var(--color-border-light);
  margin-bottom: var(--space-xs);
  transition: border-color 0.2s;
}

.pub-list li:hover {
  border-left-color: var(--color-text-muted);
}

.pub-list li em {
  color: var(--color-text);
}

.pub-list li a {
  font-size: 0.78rem;
  color: var(--color-link);
  border-bottom-color: var(--color-border);
}

.pub-note {
  margin-top: var(--space-md);
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

.pub-note a {
  color: var(--color-text-secondary);
}

/* ========================================
   Projects
   ======================================== */

.project-card {
  padding: var(--space-lg);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  margin-bottom: var(--space-sm);
  transition: border-color 0.2s;
}

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

.project-badge {
  display: inline-block;
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 3px 10px;
  border-radius: 100px;
  background: var(--color-accent);
  color: var(--color-bg);
  margin-bottom: var(--space-sm);
}

.project-card h3 {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  font-weight: 400;
  margin-bottom: var(--space-xs);
}

.project-meta {
  font-size: 0.78rem;
  color: var(--color-text-muted);
  margin-bottom: var(--space-sm);
}

.project-card p:last-child {
  font-size: 0.88rem;
  color: var(--color-text-secondary);
}

/* ========================================
   Teaching
   ======================================== */

.teaching-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: var(--space-sm);
}

.teaching-item {
  padding: var(--space-md) var(--space-lg);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  font-size: 0.88rem;
  color: var(--color-text-secondary);
  transition: border-color 0.2s, color 0.2s;
}

.teaching-item:hover {
  border-color: var(--color-text-muted);
  color: var(--color-text);
}

/* ========================================
   Contact
   ======================================== */

.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
}

.contact-card {
  padding: var(--space-lg);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 8px;
}

.contact-card h3 {
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-md);
}

.contact-card p {
  font-size: 0.88rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

.contact-card a {
  color: var(--color-text-secondary);
  border-bottom-color: var(--color-border);
}

.contact-card a:hover {
  color: var(--color-text);
}

.profile-links {
  list-style: none;
}

.profile-links li {
  margin-bottom: var(--space-sm);
}

.profile-links a {
  font-size: 0.88rem;
}

/* ========================================
   Footer
   ======================================== */

.footer {
  padding: var(--space-lg) 0;
  border-top: 1px solid var(--color-border);
  text-align: center;
}

.footer p {
  font-size: 0.78rem;
  color: var(--color-text-muted);
}

/* ========================================
   Animations
   ======================================== */

.section {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.section.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ========================================
   Responsive
   ======================================== */

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: rgba(250, 250, 249, 0.98);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    flex-direction: column;
    padding: var(--space-lg);
    gap: 0;
    border-bottom: 1px solid var(--color-border);
  }

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

  .nav-links li {
    padding: var(--space-sm) 0;
  }

  .nav-links .lang-switch {
    margin-top: var(--space-sm);
    padding-top: var(--space-md);
    border-top: 1px solid var(--color-border);
  }

  .nav-toggle {
    display: flex;
  }

  .hero {
    padding: calc(64px + var(--space-2xl)) 0 var(--space-lg);
  }

  .hero-inner {
    flex-direction: column;
    text-align: center;
    gap: var(--space-lg);
  }

  .hero-photo {
    width: 140px;
    height: 140px;
  }

  .hero-title {
    font-size: 1.8rem;
  }

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

  .timeline-item {
    flex-direction: column;
    gap: var(--space-xs);
  }

  .timeline-year {
    min-width: auto;
  }

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

  .teaching-grid {
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--space-md);
  }

  .section {
    padding: var(--space-xl) 0;
  }

  .hero-fields span {
    font-size: 0.7rem;
    padding: 4px 10px;
  }

  .hero-title {
    font-size: 1.5rem;
    letter-spacing: 0.06em;
  }
}