/* Modern Custom Design System for celalp.github.io */

:root {
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-heading: 'Outfit', 'Inter', -apple-system, sans-serif;
  --font-mono: 'Fira Code', monospace;
  
  --color-primary: #4f46e5;
  --color-primary-hover: #4338ca;
  --color-primary-light: #eef2ff;
  --color-secondary: #0d9488;
  --color-dark: #0f172a;
  --color-slate-800: #1e293b;
  --color-slate-600: #475569;
  --color-slate-500: #64748b;
  --color-slate-100: #f1f5f9;
  --color-bg-alt: #f8fafc;
  --color-border: #e2e8f0;
  --color-border-hover: #cbd5e1;
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-full: 9999px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 16px -2px rgba(15, 23, 42, 0.06), 0 2px 6px -1px rgba(15, 23, 42, 0.04);
  --shadow-lg: 0 12px 32px -4px rgba(15, 23, 42, 0.12), 0 4px 12px -2px rgba(15, 23, 42, 0.06);
  --transition-fast: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Global Typography & Font Overrides */
body {
  font-family: var(--font-sans);
  color: var(--color-slate-800);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6, .site-title {
  font-family: var(--font-heading);
  letter-spacing: -0.02em;
  font-weight: 700;
  color: var(--color-dark);
}

/* Custom Navigation Bar Enhancement */
.masthead {
  border-bottom: 1px solid var(--color-border);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  position: sticky;
  top: 0;
  z-index: 100;
}

.masthead__menu-item {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.95rem;
}

.masthead__menu-item a {
  color: var(--color-slate-600);
  transition: var(--transition-fast);
}

.masthead__menu-item a:hover {
  color: var(--color-primary);
}

/* Author Profile Sidebar Refinement */
.author__avatar img {
  border-radius: 50% !important;
  box-shadow: 0 4px 16px rgba(15, 23, 42, 0.12);
  border: 3px solid #ffffff;
}

.author__name {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.25rem;
}

.author__bio {
  font-size: 0.9rem;
  color: var(--color-slate-600);
  line-height: 1.5;
}

.author__urls a {
  border-radius: var(--radius-sm);
  padding: 4px 8px;
  transition: var(--transition-fast);
}

.author__urls a:hover {
  background: var(--color-slate-100);
  color: var(--color-primary);
}

/* Hero Section Component */
.hero-card {
  background: linear-gradient(135deg, #0f172a 0%, #1e293b 55%, #312e81 100%);
  color: #ffffff;
  padding: 2.5rem 2rem;
  border-radius: var(--radius-lg);
  margin-bottom: 2.5rem;
  box-shadow: var(--shadow-lg);
  position: relative;
  overflow: hidden;
}

.hero-card::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 350px;
  height: 350px;
  background: radial-gradient(circle, rgba(99, 102, 241, 0.25) 0%, rgba(0,0,0,0) 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero-badge {
  display: inline-block;
  background: rgba(99, 102, 241, 0.25);
  border: 1px solid rgba(165, 180, 252, 0.4);
  color: #c7d2fe;
  font-size: 0.825rem;
  font-weight: 600;
  padding: 0.3rem 0.85rem;
  border-radius: var(--radius-full);
  margin-bottom: 1rem;
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

.hero-title {
  color: #ffffff !important;
  font-size: 2.25rem;
  margin-top: 0;
  margin-bottom: 0.75rem;
  line-height: 1.2;
}

.hero-subtitle {
  font-size: 1.1rem;
  color: #cbd5e1;
  max-width: 680px;
  margin-bottom: 1.5rem;
  line-height: 1.6;
}

.hero-actions {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-top: 1.5rem;
}

.btn-custom-primary {
  background-color: var(--color-primary);
  color: #ffffff !important;
  font-family: var(--font-heading);
  font-weight: 600;
  padding: 0.65rem 1.4rem;
  border-radius: var(--radius-md);
  text-decoration: none !important;
  transition: var(--transition-fast);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  box-shadow: 0 4px 12px rgba(79, 70, 229, 0.3);
}

.btn-custom-primary:hover {
  background-color: var(--color-primary-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(79, 70, 229, 0.4);
}

.btn-custom-secondary {
  background-color: rgba(255, 255, 255, 0.1);
  color: #ffffff !important;
  border: 1px solid rgba(255, 255, 255, 0.25);
  font-family: var(--font-heading);
  font-weight: 600;
  padding: 0.65rem 1.4rem;
  border-radius: var(--radius-md);
  text-decoration: none !important;
  transition: var(--transition-fast);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  backdrop-filter: blur(4px);
}

.btn-custom-secondary:hover {
  background-color: rgba(255, 255, 255, 0.2);
  border-color: rgba(255, 255, 255, 0.4);
  transform: translateY(-2px);
}

/* Metric / Highlight Stats Grid */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1rem;
  margin-bottom: 2.5rem;
}

.stat-card {
  background: #ffffff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: var(--transition-fast);
}

.stat-card:hover {
  transform: translateY(-3px);
  border-color: var(--color-border-hover);
  box-shadow: var(--shadow-md);
}

.stat-value {
  font-family: var(--font-heading);
  font-size: 2rem;
  font-weight: 800;
  color: var(--color-primary);
  line-height: 1;
  margin-bottom: 0.35rem;
}

.stat-label {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-slate-600);
}

/* Cards & Content Containers */
.custom-card {
  background: #ffffff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin-bottom: 1.25rem;
  box-shadow: var(--shadow-sm);
  transition: var(--transition-fast);
  position: relative;
}

.custom-card:hover {
  border-color: #cbd5e1;
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.custom-card-title {
  font-size: 1.2rem;
  margin-top: 0;
  margin-bottom: 0.5rem;
}

.custom-card-title a {
  color: var(--color-dark);
  text-decoration: none;
  transition: var(--transition-fast);
}

.custom-card-title a:hover {
  color: var(--color-primary);
}

/* Badges & Pills */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.25rem 0.65rem;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 600;
  margin-right: 0.4rem;
  margin-bottom: 0.4rem;
}

.badge-venue {
  background: #e0e7ff;
  color: #3730a3;
  border: 1px solid #c7d2fe;
}

.badge-jama {
  background: #fee2e2;
  color: #991b1b;
  border: 1px solid #fca5a5;
}

.badge-nature {
  background: #d1fae5;
  color: #065f46;
  border: 1px solid #6ee7b7;
}

.badge-elife {
  background: #e0f2fe;
  color: #075985;
  border: 1px solid #7dd3fc;
}

.badge-tech {
  background: var(--color-slate-100);
  color: var(--color-slate-800);
  border: 1px solid #e2e8f0;
  font-family: var(--font-mono);
  font-size: 0.725rem;
}

/* Project Cards Grid */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.25rem;
  margin-top: 1rem;
  margin-bottom: 2rem;
}

.project-card {
  background: #ffffff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  box-shadow: var(--shadow-sm);
  transition: var(--transition-fast);
}

.project-card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}

.project-title {
  font-size: 1.25rem;
  font-family: var(--font-heading);
  margin-top: 0;
  margin-bottom: 0.5rem;
  color: var(--color-dark);
}

.project-desc {
  font-size: 0.925rem;
  color: var(--color-slate-600);
  line-height: 1.6;
  flex-grow: 1;
  margin-bottom: 1.25rem;
}

.project-tags {
  margin-bottom: 1rem;
}

.project-link {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--color-primary) !important;
  text-decoration: none !important;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  transition: var(--transition-fast);
}

.project-link:hover {
  color: var(--color-primary-hover) !important;
  gap: 0.65rem;
}

/* Publication Styling */
.publication-item {
  background: #ffffff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin-bottom: 1.25rem;
  box-shadow: var(--shadow-sm);
  transition: var(--transition-fast);
}

.publication-item:hover {
  border-color: #cbd5e1;
  box-shadow: var(--shadow-md);
}

.pub-title {
  font-size: 1.15rem;
  font-family: var(--font-heading);
  font-weight: 700;
  margin-top: 0;
  margin-bottom: 0.4rem;
  color: var(--color-dark);
  line-height: 1.4;
}

.pub-meta {
  font-size: 0.875rem;
  color: var(--color-slate-500);
  margin-bottom: 0.75rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.pub-authors {
  font-size: 0.9rem;
  color: var(--color-slate-800);
  margin-bottom: 0.65rem;
  line-height: 1.5;
}

.pub-authors strong {
  color: var(--color-primary);
}

.pub-synopsis {
  font-size: 0.925rem;
  color: var(--color-slate-600);
  background: var(--color-bg-alt);
  border-left: 3px solid var(--color-primary);
  padding: 0.6rem 0.85rem;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin-bottom: 0.85rem;
}

.pub-abstract-details {
  font-size: 0.875rem;
  color: var(--color-slate-600);
  margin-top: 0.5rem;
}

.pub-abstract-details summary {
  font-weight: 600;
  color: var(--color-slate-600);
  cursor: pointer;
  padding: 0.25rem 0;
  transition: var(--transition-fast);
}

.pub-abstract-details summary:hover {
  color: var(--color-primary);
}

/* Resume Experience Timeline */
.timeline {
  position: relative;
  padding-left: 1.75rem;
  margin: 1.5rem 0;
}

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

.timeline-item {
  position: relative;
  margin-bottom: 1.75rem;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -1.6rem;
  top: 0.4rem;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--color-primary);
  border: 3px solid #ffffff;
  box-shadow: 0 0 0 2px var(--color-primary);
}

.timeline-role {
  font-size: 1.15rem;
  font-weight: 700;
  font-family: var(--font-heading);
  margin: 0;
  color: var(--color-dark);
}

.timeline-company {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 0.25rem;
}

.timeline-date {
  font-size: 0.825rem;
  color: var(--color-slate-500);
  font-weight: 500;
  margin-bottom: 0.5rem;
}

.timeline-desc ul {
  margin: 0.5rem 0 0 0;
  padding-left: 1.2rem;
  font-size: 0.925rem;
  color: var(--color-slate-600);
}

.timeline-desc li {
  margin-bottom: 0.35rem;
}

/* Hide Jekyll default footer if desired */
.site-footer {
  display: block !important;
  background: var(--color-slate-800);
  color: var(--color-slate-500);
  padding: 2rem 0;
  border-top: 1px solid #334155;
  text-align: center;
  font-size: 0.875rem;
}