/* ========================================
   Emoji Site - Main Stylesheet
   ======================================== */

/* ========================================
   CSS Custom Properties (Variables)
   ======================================== */

:root {
  /* Colors - Light Theme (Default) */
  --color-bg: #ffffff;
  --color-bg-alt: #f8f9fa;
  --color-text: #1a1a1a;
  --color-text-muted: #6b7280;
  --color-border: #e5e7eb;
  
  /* Accent Colors */
  --color-primary: #6366f1;
  --color-primary-hover: #4f46e5;
  --color-primary-light: #e0e7ff;
  
  /* Emoji Card */
  --color-card-bg: #ffffff;
  --color-card-bg-hover: #f3f4f6;
  --color-card-border: #e5e7eb;
  --color-card-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
  --color-card-shadow-hover: 0 4px 12px rgba(0, 0, 0, 0.15);
  
  /* Header */
  --color-header-bg: #ffffff;
  --color-header-border: #e5e7eb;
  
  /* Input */
  --color-input-bg: #f3f4f6;
  --color-input-bg-focus: #ffffff;
  --color-input-border: transparent;
  --color-input-border-focus: var(--color-primary);
  
  /* Toast */
  --color-toast-bg: #1f2937;
  --color-toast-text: #ffffff;
  
  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  
  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 2rem;
  
  /* Layout */
  --container-max-width: 1200px;
  --container-padding: var(--space-4);
  
  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 350ms ease;
}

/* Dark Theme */
[data-theme="dark"] {
  --color-bg: #0f0f0f;
  --color-bg-alt: #1a1a1a;
  --color-text: #ffffff;
  --color-text-muted: #9ca3af;
  --color-border: #2d2d2d;
  
  --color-primary: #818cf8;
  --color-primary-hover: #6366f1;
  --color-primary-light: #1e1b4b;
  
  --color-card-bg: #1a1a1a;
  --color-card-bg-hover: #262626;
  --color-card-border: #2d2d2d;
  --color-card-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
  --color-card-shadow-hover: 0 4px 12px rgba(0, 0, 0, 0.4);
  
  --color-header-bg: #1a1a1a;
  --color-header-border: #2d2d2d;
  
  --color-input-bg: #262626;
  --color-input-bg-focus: #1a1a1a;
  --color-input-border: transparent;
  --color-input-border-focus: var(--color-primary);
  
  --color-toast-bg: #374151;
  --color-toast-text: #ffffff;
}

/* ========================================
   Reset & Base Styles
   ======================================== */

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  font-size: var(--font-size-base);
  line-height: 1.5;
  color: var(--color-text);
  background-color: var(--color-bg);
  min-height: 100vh;
  transition: background-color var(--transition-base), color var(--transition-base);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ========================================
   Layout
   ======================================== */

.container {
  width: 100%;
  max-width: var(--container-max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--container-padding);
  padding-right: var(--container-padding);
}

/* ========================================
   Header
   ======================================== */

.site-header {
  background-color: var(--color-header-bg);
  border-bottom: 1px solid var(--color-header-border);
  padding-top: var(--space-4);
  padding-bottom: var(--space-4);
  position: sticky;
  top: 0;
  z-index: 100;
  transition: background-color var(--transition-base), border-color var(--transition-base);
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  margin-bottom: var(--space-4);
}

.logo a {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  text-decoration: none;
  color: var(--color-text);
  font-size: var(--font-size-xl);
  font-weight: 700;
}

.logo-emoji {
  font-size: 1.75rem;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

/* ========================================
   Search
   ======================================== */

.search-container {
  position: relative;
  display: flex;
  align-items: center;
}

#emoji-search {
  width: 240px;
  padding: var(--space-3) var(--space-4);
  padding-right: 2.5rem;
  background-color: var(--color-input-bg);
  border: 2px solid var(--color-input-border);
  border-radius: var(--radius-full);
  font-size: var(--font-size-base);
  color: var(--color-text);
  transition: all var(--transition-base);
}

#emoji-search:focus {
  outline: none;
  background-color: var(--color-input-bg-focus);
  border-color: var(--color-input-border-focus);
  width: 280px;
}

#emoji-search::placeholder {
  color: var(--color-text-muted);
}

.search-clear {
  position: absolute;
  right: var(--space-3);
  background: none;
  border: none;
  color: var(--color-text-muted);
  cursor: pointer;
  font-size: var(--font-size-sm);
  padding: var(--space-1);
  border-radius: var(--radius-sm);
  transition: color var(--transition-fast);
}

.search-clear:hover {
  color: var(--color-text);
}

/* ========================================
   Theme Toggle
   ======================================== */

.theme-toggle {
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  padding: var(--space-2);
  border-radius: var(--radius-md);
  transition: background-color var(--transition-fast);
}

.theme-toggle:hover {
  background-color: var(--color-bg-alt);
}

.theme-icon {
  display: block;
}

[data-theme="light"] .theme-icon.dark,
[data-theme="dark"] .theme-icon.light {
  display: none;
}

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

.category-nav {
  display: flex;
  gap: var(--space-2);
  overflow-x: auto;
  padding-bottom: var(--space-2);
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}

.category-nav::-webkit-scrollbar {
  display: none;
}

.category-btn {
  flex-shrink: 0;
  padding: var(--space-2) var(--space-4);
  background-color: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.category-btn:hover {
  background-color: var(--color-bg-alt);
  color: var(--color-text);
}

.category-btn.active {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: white;
}

/* ========================================
   Main Content
   ======================================== */

.site-main {
  padding-top: var(--space-6);
  padding-bottom: var(--space-12);
}

.results-info {
  margin-bottom: var(--space-4);
  color: var(--color-text-muted);
  font-size: var(--font-size-sm);
}

/* ========================================
   Emoji Grid
   ======================================== */

.emoji-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
  gap: var(--space-3);
}

.emoji-card {
  aspect-ratio: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3);
  background-color: var(--color-card-bg);
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--color-card-shadow);
  cursor: pointer;
  transition: all var(--transition-base);
}

.emoji-card:hover {
  background-color: var(--color-card-bg-hover);
  border-color: var(--color-primary);
  box-shadow: var(--color-card-shadow-hover);
  transform: translateY(-2px);
}

.emoji-card:active {
  transform: translateY(0) scale(0.98);
}

.emoji-card .emoji {
  font-size: 2.5rem;
  line-height: 1;
}

.emoji-card .emoji-name {
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
  text-align: center;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  width: 100%;
}

/* Loading State */
.loading-state {
  grid-column: 1 / -1;
  text-align: center;
  padding: var(--space-12);
  color: var(--color-text-muted);
}

.loading-state p {
  font-size: var(--font-size-lg);
}

/* No Results */
.no-results {
  text-align: center;
  padding: var(--space-12);
  color: var(--color-text-muted);
}

.no-results p {
  font-size: var(--font-size-lg);
  margin-bottom: var(--space-4);
}

/* ========================================
   Recently Used Section
   ======================================== */

.recently-used-section {
  margin-top: var(--space-12);
  padding-top: var(--space-8);
  border-top: 1px solid var(--color-border);
}

.recently-used-section h2 {
  font-size: var(--font-size-xl);
  margin-bottom: var(--space-4);
  color: var(--color-text);
}

.recently-used-grid {
  grid-template-columns: repeat(auto-fill, minmax(60px, 1fr));
}

.recently-used-grid .emoji-card {
  aspect-ratio: 1;
}

.recently-used-grid .emoji-card .emoji {
  font-size: 2rem;
}

.recently-used-grid .emoji-card .emoji-name {
  display: none;
}

/* ========================================
   Buttons
   ======================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-3) var(--space-5);
  font-size: var(--font-size-sm);
  font-weight: 500;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
}

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

.btn-secondary:hover {
  background-color: var(--color-card-bg-hover);
}

.btn-text {
  background: none;
  color: var(--color-primary);
  padding: var(--space-2) var(--space-3);
}

.btn-text:hover {
  text-decoration: underline;
}

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

.site-footer {
  background-color: var(--color-bg-alt);
  border-top: 1px solid var(--color-border);
  padding-top: var(--space-8);
  padding-bottom: var(--space-8);
  text-align: center;
}

.footer-text {
  color: var(--color-text-muted);
  margin-bottom: var(--space-2);
}

.footer-text a {
  color: var(--color-primary);
}

.footer-copy {
  color: var(--color-text-muted);
  font-size: var(--font-size-sm);
}

/* ========================================
   Toast Notification
   ======================================== */

.toast {
  position: fixed;
  bottom: var(--space-6);
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background-color: var(--color-toast-bg);
  color: var(--color-toast-text);
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-full);
  font-size: var(--font-size-sm);
  font-weight: 500;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
  opacity: 0;
  transition: transform var(--transition-base), opacity var(--transition-base);
  z-index: 1000;
}

.toast.show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

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

@media (max-width: 768px) {
  .header-content {
    flex-direction: column;
    gap: var(--space-3);
  }
  
  .header-actions {
    width: 100%;
    justify-content: space-between;
  }
  
  #emoji-search {
    width: 180px;
  }
  
  #emoji-search:focus {
    width: 200px;
  }
  
  .emoji-grid {
    grid-template-columns: repeat(auto-fill, minmax(70px, 1fr));
    gap: var(--space-2);
  }
  
  .emoji-card .emoji {
    font-size: 2rem;
  }
  
  .category-nav {
    gap: var(--space-1);
  }
  
  .category-btn {
    padding: var(--space-2) var(--space-3);
    font-size: var(--font-size-xs);
  }
}

@media (max-width: 480px) {
  :root {
    --container-padding: var(--space-3);
  }
  
  .emoji-grid {
    grid-template-columns: repeat(auto-fill, minmax(60px, 1fr));
  }
  
  .emoji-card .emoji {
    font-size: 1.75rem;
  }
  
  .emoji-card .emoji-name {
    font-size: 10px;
  }
}

/* ========================================
   Accessibility
   ======================================== */

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* Focus visible for keyboard navigation */
.emoji-card:focus-visible,
.category-btn:focus-visible,
#emoji-search:focus-visible,
.theme-toggle:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Screen reader only */
.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;
}