/* ===================================
   CSS Variables & Design System
   =================================== */
:root {
  /* Colors */
  --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  --accent-gradient: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
  --success-gradient: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
  
  --bg-primary: #0a0e27;
  --bg-secondary: #151932;
  --bg-tertiary: #1e2442;
  --bg-card: rgba(30, 36, 66, 0.6);
  
  --text-primary: #ffffff;
  --text-secondary: #a0aec0;
  --text-muted: #718096;
  
  --accent-purple: #667eea;
  --accent-pink: #f5576c;
  --accent-blue: #4facfe;
  --accent-cyan: #00f2fe;
  
  /* Gradients */
  --glass-bg: rgba(255, 255, 255, 0.05);
  --glass-border: rgba(255, 255, 255, 0.1);
  
  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  
  /* Border Radius */
  --radius-sm: 0.5rem;
  --radius-md: 1rem;
  --radius-lg: 1.5rem;
  --radius-xl: 2rem;
  
  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.2);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.3);
  --shadow-glow: 0 0 40px rgba(102, 126, 234, 0.3);
  
  /* Typography */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-display: 'Playfair Display', serif;
  
  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-primary);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  position: relative;
}

/* Background Gradient Animation */
.bg-gradient {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: 
    radial-gradient(circle at 20% 20%, rgba(102, 126, 234, 0.15) 0%, transparent 50%),
    radial-gradient(circle at 80% 80%, rgba(245, 87, 108, 0.15) 0%, transparent 50%),
    radial-gradient(circle at 50% 50%, rgba(79, 172, 254, 0.1) 0%, transparent 70%);
  z-index: -1;
  animation: gradientShift 15s ease infinite;
}

@keyframes gradientShift {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.8; transform: scale(1.1); }
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* ===================================
   Header
   =================================== */
.header {
  padding: var(--spacing-md) 0;
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--glass-border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-family: var(--font-display);
}

.logo i {
  font-size: 2rem;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.logo h1 {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--text-primary);
}

.gradient-text {
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav {
  display: flex;
  gap: var(--spacing-sm);
}

.nav-btn {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: 0.75rem 1.25rem;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-normal);
}

.nav-btn:hover {
  background: var(--glass-border);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.nav-btn i {
  font-size: 1.1rem;
}

/* ===================================
   Hero Section
   =================================== */
.hero {
  text-align: center;
  padding: var(--spacing-xl) 0;
  margin-top: var(--spacing-lg);
}

.hero-title {
  font-family: var(--font-display);
  font-size: 3.5rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
  animation: fadeInUp 0.8s ease;
}

.hero-subtitle {
  font-size: 1.2rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-xl);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
  animation: fadeInUp 0.8s ease 0.2s backwards;
}

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

/* ===================================
   Search Bar
   =================================== */
.search-container {
  max-width: 700px;
  margin: 0 auto var(--spacing-lg);
  position: relative;
  animation: fadeInUp 0.8s ease 0.4s backwards;
}

.search-box {
  display: flex;
  align-items: center;
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  border: 2px solid var(--glass-border);
  border-radius: var(--radius-xl);
  padding: 0.5rem 0.5rem 0.5rem 1.5rem;
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-lg);
}

.search-box:focus-within {
  border-color: var(--accent-purple);
  box-shadow: var(--shadow-glow);
  transform: translateY(-2px);
}

.search-icon {
  color: var(--text-muted);
  font-size: 1.3rem;
  margin-right: var(--spacing-sm);
}

.search-input {
  flex: 1;
  background: transparent;
  border: none;
  outline: none;
  color: var(--text-primary);
  font-size: 1.1rem;
  padding: 0.75rem 0;
  font-family: var(--font-primary);
}

.search-input::placeholder {
  color: var(--text-muted);
}

.search-btn {
  background: var(--primary-gradient);
  border: none;
  border-radius: var(--radius-lg);
  width: 50px;
  height: 50px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-md);
}

.search-btn:hover {
  transform: scale(1.05);
  box-shadow: 0 0 20px rgba(102, 126, 234, 0.5);
}

.search-btn i {
  color: white;
  font-size: 1.2rem;
}

/* Suggestions dropdown */
.suggestions {
  position: absolute;
  top: calc(100% + 0.5rem);
  left: 0;
  right: 0;
  background: var(--bg-card);
  backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  max-height: 300px;
  overflow-y: auto;
  display: none;
  box-shadow: var(--shadow-lg);
  z-index: 10;
}

.suggestion-item {
  padding: var(--spacing-sm) var(--spacing-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  border-bottom: 1px solid var(--glass-border);
}

.suggestion-item:last-child {
  border-bottom: none;
}

.suggestion-item:hover {
  background: var(--glass-border);
}

/* ===================================
   Quick Search
   =================================== */
.quick-search {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
  animation: fadeInUp 0.8s ease 0.6s backwards;
}

.quick-label {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.quick-word {
  padding: 0.5rem 1rem;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-size: 0.9rem;
  cursor: pointer;
  transition: all var(--transition-normal);
}

.quick-word:hover {
  background: var(--primary-gradient);
  color: white;
  border-color: transparent;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* ===================================
   Loading & Error States
   =================================== */
.loading-state,
.error-state {
  text-align: center;
  padding: var(--spacing-xl) var(--spacing-md);
  margin: var(--spacing-xl) 0;
}

.loading-spinner {
  width: 60px;
  height: 60px;
  border: 4px solid var(--glass-border);
  border-top: 4px solid var(--accent-purple);
  border-radius: 50%;
  margin: 0 auto var(--spacing-md);
  animation: spin 1s linear infinite;
}

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

.loading-state p {
  color: var(--text-secondary);
  font-size: 1.1rem;
}

.error-state i {
  font-size: 4rem;
  color: var(--accent-pink);
  margin-bottom: var(--spacing-md);
}

.error-state h3 {
  font-size: 1.8rem;
  margin-bottom: var(--spacing-sm);
}

.error-state p {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-md);
}

.hidden {
  display: none !important;
}

/* ===================================
   Results Section
   =================================== */
.results-section {
  max-width: 900px;
  margin: var(--spacing-xl) auto;
  animation: fadeInUp 0.6s ease;
}

.word-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: var(--spacing-lg);
  padding: var(--spacing-lg);
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

.word-title {
  font-family: var(--font-display);
  font-size: 3rem;
  font-weight: 800;
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: var(--spacing-xs);
}

.phonetics {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  align-items: center;
  margin-top: var(--spacing-sm);
}

.phonetic-text {
  color: var(--text-secondary);
  font-size: 1.2rem;
  font-style: italic;
}

.audio-btn {
  background: var(--accent-gradient);
  border: none;
  border-radius: 50%;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-sm);
}

.audio-btn:hover {
  transform: scale(1.1);
  box-shadow: 0 0 20px rgba(79, 172, 254, 0.5);
}

.audio-btn i {
  color: white;
  font-size: 1rem;
}

.icon-btn {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: 50%;
  width: 50px;
  height: 50px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-normal);
}

.icon-btn:hover {
  background: var(--glass-border);
  transform: scale(1.1);
}

.icon-btn i {
  font-size: 1.3rem;
  color: var(--text-secondary);
}

.favorite-btn.active i {
  color: var(--accent-pink);
}

.favorite-btn.active {
  background: rgba(245, 87, 108, 0.1);
  border-color: var(--accent-pink);
}

/* ===================================
   Meanings
   =================================== */
.meanings-container {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.meaning-card {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
}

.meaning-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(102, 126, 234, 0.3);
}

.part-of-speech {
  display: inline-block;
  background: var(--primary-gradient);
  color: white;
  padding: 0.4rem 1rem;
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: var(--spacing-md);
  text-transform: capitalize;
}

.definitions-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.definition-item {
  position: relative;
  padding-left: 2rem;
}

.definition-item::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.5rem;
  width: 8px;
  height: 8px;
  background: var(--accent-gradient);
  border-radius: 50%;
}

.definition-text {
  color: var(--text-primary);
  font-size: 1.05rem;
  line-height: 1.8;
  margin-bottom: var(--spacing-xs);
}

.example {
  color: var(--text-muted);
  font-style: italic;
  margin-top: var(--spacing-xs);
  padding-left: var(--spacing-md);
  border-left: 3px solid var(--glass-border);
}

.example::before {
  content: '"';
  color: var(--accent-purple);
}

.example::after {
  content: '"';
  color: var(--accent-purple);
}

/* ===================================
   Synonyms & Antonyms
   =================================== */
.synonyms-antonyms {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-lg);
  margin-top: var(--spacing-lg);
}

.word-list-section {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow-md);
}

.word-list-section h3 {
  font-size: 1.3rem;
  margin-bottom: var(--spacing-md);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  color: var(--text-primary);
}

.word-list-section h3 i {
  font-size: 1.1rem;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.word-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
}

.word-tag {
  padding: 0.5rem 1rem;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-size: 0.9rem;
  cursor: pointer;
  transition: all var(--transition-normal);
}

.word-tag:hover {
  background: var(--accent-gradient);
  color: white;
  border-color: transparent;
  transform: translateY(-2px);
}

/* ===================================
   Origin Section
   =================================== */
.origin-section {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  margin-top: var(--spacing-lg);
  box-shadow: var(--shadow-md);
}

.origin-section h3 {
  font-size: 1.3rem;
  margin-bottom: var(--spacing-md);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.origin-section h3 i {
  background: var(--success-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.origin-text {
  color: var(--text-secondary);
  line-height: 1.8;
  font-size: 1.05rem;
}

/* ===================================
   Source Section
   =================================== */
.source-section {
  margin-top: var(--spacing-lg);
  padding: var(--spacing-md);
  border-top: 1px solid var(--glass-border);
  text-align: center;
}

.source-section p {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.source-section a {
  color: var(--accent-blue);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.source-section a:hover {
  color: var(--accent-cyan);
  text-decoration: underline;
}

/* ===================================
   Sidebar
   =================================== */
.sidebar {
  position: fixed;
  top: 0;
  right: -400px;
  width: 400px;
  height: 100%;
  background: var(--bg-secondary);
  box-shadow: var(--shadow-lg);
  z-index: 1000;
  transition: right var(--transition-normal);
  display: flex;
  flex-direction: column;
}

.sidebar.active {
  right: 0;
}

.sidebar-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-lg);
  background: var(--glass-bg);
  border-bottom: 1px solid var(--glass-border);
}

.sidebar-header h3 {
  font-size: 1.3rem;
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.close-btn {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: 50%;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-normal);
}

.close-btn:hover {
  background: var(--glass-border);
  transform: rotate(90deg);
}

.sidebar-content {
  flex: 1;
  padding: var(--spacing-md);
  overflow-y: auto;
}

.history-list,
.favorites-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.history-item,
.favorite-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-md);
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-normal);
}

.history-item:hover,
.favorite-item:hover {
  background: var(--glass-border);
  transform: translateX(-4px);
}

.history-word,
.favorite-word {
  font-weight: 600;
  color: var(--text-primary);
}

.history-time {
  color: var(--text-muted);
  font-size: 0.85rem;
}

.delete-btn {
  background: transparent;
  border: none;
  color: var(--accent-pink);
  cursor: pointer;
  padding: 0.5rem;
  transition: all var(--transition-fast);
  opacity: 0.7;
}

.delete-btn:hover {
  opacity: 1;
  transform: scale(1.2);
}

.btn-secondary {
  width: 100%;
  padding: var(--spacing-sm);
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  margin-top: var(--spacing-md);
  transition: all var(--transition-normal);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
}

.btn-secondary:hover {
  background: var(--secondary-gradient);
  color: white;
  border-color: transparent;
}

.btn-primary {
  padding: var(--spacing-sm) var(--spacing-lg);
  background: var(--primary-gradient);
  border: none;
  border-radius: var(--radius-md);
  color: white;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-normal);
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.empty-message {
  text-align: center;
  color: var(--text-muted);
  padding: var(--spacing-xl) var(--spacing-md);
}

.empty-message i {
  font-size: 3rem;
  display: block;
  margin-bottom: var(--spacing-md);
  opacity: 0.5;
}

/* ===================================
   Overlay
   =================================== */
.overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(4px);
  z-index: 999;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
}

.overlay.active {
  opacity: 1;
  visibility: visible;
}

/* ===================================
   Footer
   =================================== */
.footer {
  margin-top: var(--spacing-xl);
  padding: var(--spacing-lg) 0;
  background: var(--glass-bg);
  border-top: 1px solid var(--glass-border);
  text-align: center;
}

.footer p {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.footer a {
  color: var(--accent-blue);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer a:hover {
  color: var(--accent-cyan);
}

/* ===================================
   Custom Scrollbar
   =================================== */
::-webkit-scrollbar {
  width: 10px;
}

::-webkit-scrollbar-track {
  background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
  background: var(--glass-border);
  border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent-purple);
}

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 768px) {
  .hero-title {
    font-size: 2.5rem;
  }
  
  .hero-subtitle {
    font-size: 1rem;
  }
  
  .search-box {
    padding: 0.5rem;
  }
  
  .search-input {
    font-size: 1rem;
  }
  
  .word-title {
    font-size: 2rem;
  }
  
  .nav span {
    display: none;
  }
  
  .sidebar {
    width: 100%;
    right: -100%;
  }
  
  .word-header {
    flex-direction: column;
    gap: var(--spacing-md);
  }
  
  .synonyms-antonyms {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 2rem;
  }
  
  .quick-search {
    font-size: 0.85rem;
  }
  
  .logo h1 {
    font-size: 1.4rem;
  }
  
  .container {
    padding: 0 var(--spacing-sm);
  }
}