/* ===================================
   ISRC Central Stylesheet
   Modern, Professional Research Journal Design
   =================================== */

/* Import Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=Merriweather:wght@300;400;700&display=swap');

/* CSS Variables for Consistent Theming */
:root {
  /* Color Palette */
  --primary: #5046e5;
  --primary-dark: #4338ca;
  --primary-light: #6366f1;
  --primary-lighter: #818cf8;
  --primary-lightest: #c7d2fe;
  
  --secondary: #06b6d4;
  --secondary-dark: #0891b2;
  --secondary-light: #22d3ee;
  
  --accent: #8b5cf6;
  --accent-light: #a78bfa;
  
  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
  --info: #3b82f6;
  
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
  
  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-serif: 'Merriweather', Georgia, serif;
  
  /* Spacing */
  --container-max: 1280px;
  --container-padding: 1.5rem;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
  
  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition: 300ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
  
  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;
}

/* Reset and Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--gray-800);
  background: linear-gradient(135deg, var(--gray-50) 0%, #ffffff 50%, var(--gray-50) 100%);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  position: relative;
}

body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: 
    radial-gradient(circle at 20% 80%, rgba(80, 70, 229, 0.05) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(139, 92, 246, 0.05) 0%, transparent 50%),
    radial-gradient(circle at 40% 40%, rgba(6, 182, 212, 0.03) 0%, transparent 50%);
  pointer-events: none;
  z-index: -1;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 1rem;
  color: var(--gray-900);
}

h1 {
  font-size: clamp(2rem, 5vw, 3rem);
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 1.5rem;
}

h2 {
  font-size: clamp(1.5rem, 4vw, 2.25rem);
  margin-top: 2rem;
}

h3 {
  font-size: clamp(1.25rem, 3vw, 1.875rem);
}

.prose h1, .prose h2, .prose h3 {
  font-family: var(--font-serif);
}

p {
  margin-bottom: 1rem;
  line-height: 1.8;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--primary-dark);
}

/* Navigation Enhancements */
nav {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(229, 231, 235, 0.5);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
  transition: all var(--transition);
}

nav.scrolled {
  background: rgba(255, 255, 255, 0.98);
  box-shadow: var(--shadow-md);
}

nav h1 {
  font-size: 1.75rem;
  margin: 0;
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  font-weight: 800;
  letter-spacing: -0.5px;
}

nav a {
  position: relative;
  font-weight: 500;
  transition: all var(--transition-fast);
}

nav a:not(.bg-indigo-600)::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--primary) 0%, var(--accent) 100%);
  transition: width var(--transition);
}

nav a:hover::after {
  width: 100%;
}

nav a.active::after {
  width: 100%;
}

/* Enhanced Dropdown Menu */
.dropdown-menu {
  top: 100%;
  margin-top: 0.5rem;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: all var(--transition-fast);
  border: 1px solid var(--gray-200);
  box-shadow: var(--shadow-xl);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.dropdown:hover .dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  display: block;
}

.dropdown-menu a {
  transition: all var(--transition-fast);
  position: relative;
  overflow: hidden;
}

.dropdown-menu a::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  height: 100%;
  width: 3px;
  background: linear-gradient(180deg, var(--primary) 0%, var(--accent) 100%);
  transform: translateX(-100%);
  transition: transform var(--transition-fast);
}

.dropdown-menu a:hover::before {
  transform: translateX(0);
}

/* Card Styles */
.card, .bg-white.rounded-xl, .bg-white.rounded-lg {
  background: white;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary) 0%, var(--accent) 50%, var(--secondary) 100%);
  transform: scaleX(0);
  transition: transform var(--transition);
}

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

.card-hover:hover {
  transform: translateY(-8px) scale(1.02);
  box-shadow: var(--shadow-2xl);
}

/* Button Styles */
.btn, button[type="submit"], .bg-indigo-600 {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  font-weight: 600;
  border-radius: var(--radius);
  transition: all var(--transition-fast);
  cursor: pointer;
  position: relative;
  overflow: hidden;
  border: none;
  text-transform: none;
  letter-spacing: 0.025em;
}

.btn-primary, .bg-indigo-600 {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: white;
  box-shadow: 0 4px 15px rgba(80, 70, 229, 0.3);
}

.btn-primary:hover, .bg-indigo-600:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(80, 70, 229, 0.4);
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 100%);
}

.btn-primary::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.3);
  transform: translate(-50%, -50%);
  transition: width 0.6s, height 0.6s;
}

.btn-primary:hover::before {
  width: 300px;
  height: 300px;
}

/* Form Styles */
input, textarea, select {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 2px solid var(--gray-200);
  border-radius: var(--radius);
  font-size: 1rem;
  transition: all var(--transition-fast);
  background: white;
}

input:focus, textarea:focus, select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(80, 70, 229, 0.1);
  transform: translateY(-2px);
}

label {
  display: block;
  font-weight: 600;
  color: var(--gray-700);
  margin-bottom: 0.5rem;
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* Status Badges */
.badge, .bg-indigo-100 {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  border-radius: 9999px;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.8; }
}

/* Table Styles */
table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
}

thead {
  background: linear-gradient(135deg, var(--gray-50) 0%, var(--gray-100) 100%);
}

thead th {
  padding: 1rem;
  text-align: left;
  font-weight: 600;
  color: var(--gray-600);
  text-transform: uppercase;
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  border-bottom: 2px solid var(--gray-200);
}

tbody tr {
  transition: all var(--transition-fast);
  border-bottom: 1px solid var(--gray-100);
}

tbody tr:hover {
  background: linear-gradient(90deg, rgba(80, 70, 229, 0.05) 0%, rgba(139, 92, 246, 0.05) 100%);
}

/* Footer Enhanced */
footer {
  background: linear-gradient(180deg, white 0%, var(--gray-50) 100%);
  border-top: 1px solid var(--gray-200);
  position: relative;
  overflow: hidden;
}

footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--primary) 0%, var(--accent) 50%, var(--secondary) 100%);
}

/* Animations */
.fade-in {
  animation: fadeInUp 0.8s ease-out;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.slide-in-left {
  animation: slideInLeft 0.6s ease-out;
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* Loading Animation */
.loading {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 3px solid var(--gray-300);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* Utility Classes */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

.text-gradient {
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.glass {
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.3);
}

.hover-lift {
  transition: transform var(--transition);
}

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

/* Publication Cards Enhancement */
.paper-item, .archive-item {
  background: white;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all var(--transition);
  position: relative;
}

.paper-item::before, .archive-item::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary) 0%, var(--accent) 100%);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition);
}

.paper-item:hover::before, .archive-item:hover::before {
  transform: scaleX(1);
}

.paper-item:hover, .archive-item:hover {
  box-shadow: var(--shadow-xl);
  transform: translateY(-4px);
  border-color: var(--primary-lighter);
}

/* Line Clamp Utilities */
.line-clamp-2 {
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.line-clamp-3 {
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* Mobile Menu Enhancement */
#mobile-menu {
  background: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: var(--shadow-lg);
}

#mobile-menu a {
  transition: all var(--transition-fast);
  position: relative;
}

#mobile-menu a:hover {
  background: linear-gradient(90deg, rgba(80, 70, 229, 0.1) 0%, rgba(139, 92, 246, 0.1) 100%);
  padding-left: 2rem;
}

/* Search Input Enhancement */
#searchInput, #categoryFilter, #sortFilter {
  border: 2px solid var(--gray-200);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

#searchInput:focus, #categoryFilter:focus, #sortFilter:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(80, 70, 229, 0.1);
  transform: translateY(-2px);
}

/* Responsive Design */
@media (max-width: 1024px) {
  :root {
    --container-padding: 1rem;
  }
  
  h1 {
    font-size: 2rem;
  }
  
  h2 {
    font-size: 1.5rem;
  }
  
  .grid-cols-3 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  :root {
    --container-padding: 0.75rem;
  }
  
  body {
    font-size: 15px;
  }
  
  h1 {
    font-size: 1.75rem;
  }
  
  h2 {
    font-size: 1.25rem;
  }
  
  nav h1 {
    font-size: 1.5rem;
  }
  
  .grid-cols-2, .grid-cols-3 {
    grid-template-columns: 1fr;
  }
  
  .card {
    margin-bottom: 1rem;
  }
  
  .btn {
    width: 100%;
    padding: 1rem;
  }
  
  table {
    font-size: 0.875rem;
  }
  
  /* Stack form elements on mobile */
  .grid {
    gap: 1rem;
  }
}

@media (max-width: 480px) {
  h1 {
    font-size: 1.5rem;
  }
  
  .btn {
    font-size: 0.875rem;
  }
  
  input, textarea, select {
    font-size: 16px; /* Prevent zoom on iOS */
  }
}

/* Print Styles */
@media print {
  nav, footer, .btn, button, #mobile-menu {
    display: none;
  }
  
  body {
    background: white;
  }
  
  .card {
    box-shadow: none;
    border: 1px solid var(--gray-300);
    page-break-inside: avoid;
  }
}

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

/* Skip to content link */
.skip-to-content {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--primary);
  color: white;
  padding: 0.5rem 1rem;
  z-index: 100;
  text-decoration: none;
  border-radius: var(--radius);
}

.skip-to-content:focus {
  top: 0.5rem;
}

/* Focus visible for keyboard navigation */
*:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 12px;
  height: 12px;
}

::-webkit-scrollbar-track {
  background: var(--gray-100);
  border-radius: var(--radius);
}

::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, var(--primary) 0%, var(--accent) 100%);
  border-radius: var(--radius);
  border: 2px solid var(--gray-100);
}

::-webkit-scrollbar-thumb:hover {
  background: linear-gradient(180deg, var(--primary-dark) 0%, var(--accent) 100%);
}

/* Selection Styles */
::selection {
  background: var(--primary-lighter);
  color: white;
}

::-moz-selection {
  background: var(--primary-lighter);
  color: white;
}