/* ==========================================
   2025 모던 게시판 스타일
   ========================================== */

:root {
  /* Primary Colors */
  --primary-50: #f0f9ff;
  --primary-100: #e0f2fe;
  --primary-500: #06b6d4;
  --primary-600: #0891b2;
  --primary-700: #0e7490;
  
  /* Neutral Colors */
  --gray-50: #f8fafc;
  --gray-100: #f1f5f9;
  --gray-200: #e2e8f0;
  --gray-300: #cbd5e1;
  --gray-400: #94a3b8;
  --gray-500: #64748b;
  --gray-600: #475569;
  --gray-700: #334155;
  --gray-800: #1e293b;
  --gray-900: #0f172a;
  
  /* Accent Colors */
  --accent-purple: #8b5cf6;
  --accent-pink: #ec4899;
  --accent-orange: #f97316;
  --success: #10b981;
  --warning: #f59e0b;
  --error: #ef4444;
  
  /* Dark Theme Variables */
  --dark-bg-primary: #0f0f23;
  --dark-bg-secondary: #1a1a2e;
  --dark-surface: #16213e;
  --dark-border: #2d3748;
  
  /* Dynamic Variables (Light Mode Default) */
  --bg-primary: var(--gray-50);
  --bg-secondary: #ffffff;
  --bg-surface: #ffffff;
  --text-primary: var(--gray-900);
  --text-secondary: var(--gray-600);
  --text-muted: var(--gray-500);
  --border-color: var(--gray-200);
  --hover-bg: var(--gray-100);
  
  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-12: 3rem;
  
  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  
  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 300ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* Dark Theme */
[data-theme="dark"] {
  --bg-primary: var(--dark-bg-primary);
  --bg-secondary: var(--dark-bg-secondary);
  --bg-surface: var(--dark-surface);
  --text-primary: #f1f5f9;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  --border-color: var(--dark-border);
  --hover-bg: rgba(255, 255, 255, 0.05);
}

/* Global Styles */
* {
  box-sizing: border-box;
}

body {
  font-family: 'Inter', 'Pretendard', -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 14px;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* Container */
.modern-board-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--space-6);
  min-height: 100vh;
}

/* ==========================================
   Header Section
   ========================================== */
.board-header {
  margin-bottom: var(--space-8);
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: var(--space-6);
  flex-wrap: wrap;
}

.board-title-section {
  flex: 1;
  min-width: 300px;
}

.board-title {
  font-size: 2.5rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--primary-600), var(--accent-purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin: 0 0 var(--space-2) 0;
  letter-spacing: -0.025em;
}

.board-description {
  color: var(--text-secondary);
  font-size: 1.1rem;
  margin: 0;
  line-height: 1.5;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  flex-wrap: wrap;
}

/* Search Form */
.search-container {
  position: relative;
}

.modern-search-form {
  display: flex;
  align-items: center;
}

.search-input-group {
  display: flex;
  background: var(--bg-surface);
  border: 2px solid var(--border-color);
  border-radius: var(--radius-xl);
  overflow: hidden;
  transition: all var(--transition-fast);
  box-shadow: var(--shadow-sm);
}

.search-input-group:focus-within {
  border-color: var(--primary-500);
  box-shadow: 0 0 0 3px rgba(6, 182, 212, 0.1);
}

.search-select {
  background: transparent;
  border: none;
  padding: var(--space-3) var(--space-4);
  font-size: 0.9rem;
  color: var(--text-secondary);
  cursor: pointer;
  outline: none;
  min-width: 100px;
}

.search-input {
  flex: 1;
  border: none;
  background: transparent;
  padding: var(--space-3) var(--space-4);
  font-size: 0.9rem;
  color: var(--text-primary);
  outline: none;
  min-width: 200px;
}

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

.search-btn {
  background: var(--primary-500);
  border: none;
  padding: var(--space-3) var(--space-4);
  color: white;
  cursor: pointer;
  transition: background-color var(--transition-fast);
  display: flex;
  align-items: center;
  justify-content: center;
}

.search-btn:hover {
  background: var(--primary-600);
}

/* Write Button */
.write-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  background: linear-gradient(135deg, var(--accent-purple), var(--accent-pink));
  color: white;
  text-decoration: none;
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-xl);
  font-weight: 600;
  font-size: 0.9rem;
  transition: all var(--transition-fast);
  box-shadow: var(--shadow-md);
  white-space: nowrap;
}

.write-btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  text-decoration: none;
  color: white;
}

/* ==========================================
   Category Tabs
   ========================================== */
.category-tabs {
  margin-bottom: var(--space-6);
  overflow-x: auto;
}

.tab-list {
  display: flex;
  gap: var(--space-2);
  border-bottom: 2px solid var(--border-color);
  min-width: max-content;
  padding-bottom: 0;
}

.tab-item {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  text-decoration: none;
  color: var(--text-secondary);
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
  transition: all var(--transition-fast);
  position: relative;
  white-space: nowrap;
  font-weight: 500;
}

.tab-item:hover {
  color: var(--primary-600);
  background: var(--hover-bg);
  text-decoration: none;
}

.tab-item.active {
  color: var(--primary-600);
  background: var(--bg-surface);
  border-bottom: 2px solid var(--primary-500);
  margin-bottom: -2px;
}

.tab-count {
  background: var(--gray-200);
  color: var(--text-muted);
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  font-weight: 600;
  transition: all var(--transition-fast);
}

.tab-item.active .tab-count {
  background: var(--primary-100);
  color: var(--primary-700);
}

[data-theme="dark"] .tab-count {
  background: var(--dark-surface);
  color: var(--text-muted);
}

[data-theme="dark"] .tab-item.active .tab-count {
  background: rgba(6, 182, 212, 0.2);
  color: var(--primary-400);
}

/* ==========================================
   Post List
   ========================================== */
.post-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.post-item {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  transition: all var(--transition-fast);
  position: relative;
  overflow: hidden;
}

.post-item:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary-200);
}

.post-item.notice {
  background: linear-gradient(135deg, 
    rgba(6, 182, 212, 0.05), 
    rgba(139, 92, 246, 0.05));
  border-color: var(--primary-300);
}

.post-item.notice::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: linear-gradient(135deg, var(--primary-500), var(--accent-purple));
}

.post-main {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.post-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-3);
}

/* Category Badge */
.category-badge {
  background: var(--primary-100);
  color: var(--primary-700);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.025em;
}

[data-theme="dark"] .category-badge {
  background: rgba(6, 182, 212, 0.2);
  color: var(--primary-400);
}

/* Post Status */
.post-status {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.status-badge {
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.025em;
}

.status-badge.notice {
  background: var(--accent-orange);
  color: white;
}

.icon-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  background: var(--hover-bg);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  transition: all var(--transition-fast);
}

.icon-badge:hover {
  background: var(--primary-100);
  color: var(--primary-600);
}

/* Post Content */
.post-content {
  flex: 1;
}

.post-title {
  margin: 0 0 var(--space-2) 0;
  font-size: 1.2rem;
  font-weight: 600;
  line-height: 1.4;
}

.title-link {
  color: var(--text-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.title-link:hover {
  color: var(--primary-600);
  text-decoration: none;
}

.comment-count {
  background: var(--primary-500);
  color: white;
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 600;
  min-width: 20px;
  text-align: center;
}

.post-excerpt {
  color: var(--text-secondary);
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.5;
  overflow: hidden;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

/* Post Meta */
.post-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-4);
  flex-wrap: wrap;
}

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

.author-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary-500), var(--accent-purple));
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 600;
  font-size: 0.9rem;
  overflow: hidden;
}

.author-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.author-details {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.author-name {
  font-weight: 600;
  color: var(--text-primary);
  font-size: 0.9rem;
}

.post-date {
  color: var(--text-muted);
  font-size: 0.8rem;
}

.post-stats {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.stat-item {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  color: var(--text-muted);
  font-size: 0.85rem;
}

.stat-item svg {
  opacity: 0.7;
}

/* Post Actions */
.post-actions {
  margin-top: var(--space-4);
  padding-top: var(--space-4);
  border-top: 1px solid var(--border-color);
  display: flex;
  gap: var(--space-3);
}

.ebook-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  background: linear-gradient(135deg, var(--success), #059669);
  color: white;
  border: none;
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-lg);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
  box-shadow: var(--shadow-sm);
}

.ebook-btn:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
  background: linear-gradient(135deg, #059669, #047857);
}

/* ==========================================
   Empty State
   ========================================== */
.empty-state {
  text-align: center;
  padding: var(--space-12);
  color: var(--text-muted);
}

.empty-icon {
  margin: 0 auto var(--space-6) auto;
  opacity: 0.5;
}

.empty-state h3 {
  margin: 0 0 var(--space-2) 0;
  color: var(--text-secondary);
  font-size: 1.2rem;
  font-weight: 600;
}

.empty-state p {
  margin: 0 0 var(--space-6) 0;
  color: var(--text-muted);
}

.empty-action-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  background: var(--primary-500);
  color: white;
  text-decoration: none;
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-lg);
  font-weight: 600;
  transition: all var(--transition-fast);
  box-shadow: var(--shadow-md);
}

.empty-action-btn:hover {
  background: var(--primary-600);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  text-decoration: none;
  color: white;
}

/* ==========================================
   Theme Toggle
   ========================================== */
.theme-toggle {
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-6);
  width: 56px;
  height: 56px;
  background: var(--bg-surface);
  border: 2px solid var(--border-color);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
  box-shadow: var(--shadow-lg);
  z-index: 1000;
}

.theme-toggle:hover {
  transform: scale(1.1);
  box-shadow: var(--shadow-xl);
}

.theme-toggle .moon-icon {
  display: none;
}

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

[data-theme="dark"] .theme-toggle .moon-icon {
  display: block;
}

/* ==========================================
   Responsive Design
   ========================================== */
@media (max-width: 768px) {
  .modern-board-container {
    padding: var(--space-4);
  }
  
  .header-content {
    flex-direction: column;
    align-items: stretch;
    gap: var(--space-4);
  }
  
  .board-title {
    font-size: 2rem;
  }
  
  .header-actions {
    flex-direction: column;
    align-items: stretch;
  }
  
  .search-input-group {
    flex-direction: column;
    border-radius: var(--radius-lg);
  }
  
  .search-select,
  .search-input {
    min-width: auto;
    padding: var(--space-4);
  }
  
  .search-btn {
    padding: var(--space-4);
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
  }
  
  .tab-list {
    padding: 0 var(--space-4);
    margin: 0 -var(--space-4);
  }
  
  .post-item {
    padding: var(--space-4);
  }
  
  .post-meta {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-3);
  }
  
  .post-stats {
    align-self: stretch;
    justify-content: space-between;
  }
  
  .theme-toggle {
    bottom: var(--space-4);
    right: var(--space-4);
    width: 48px;
    height: 48px;
  }
}

@media (max-width: 480px) {
  .board-title {
    font-size: 1.75rem;
  }
  
  .post-title {
    font-size: 1.1rem;
  }
  
  .author-avatar {
    width: 32px;
    height: 32px;
    font-size: 0.8rem;
  }
  
  .category-tabs {
    margin: 0 -var(--space-4) var(--space-6) -var(--space-4);
  }
}

/* ==========================================
   Animations
   ========================================== */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.post-item {
  animation: fadeInUp 0.5s ease-out;
}

.post-item:nth-child(n) {
  animation-delay: calc(0.1s * var(--animation-order, 0));
}

/* ==========================================
   Focus States
   ========================================== */
.search-input:focus,
.search-select:focus {
  outline: 2px solid var(--primary-500);
  outline-offset: -2px;
}

.write-btn:focus,
.ebook-btn:focus,
.tab-item:focus,
.theme-toggle:focus {
  outline: 2px solid var(--primary-500);
  outline-offset: 2px;
}

/* ==========================================
   Print Styles
   ========================================== */
@media print {
  .theme-toggle,
  .header-actions,
  .post-actions {
    display: none !important;
  }
  
  .post-item {
    box-shadow: none;
    border: 1px solid #ddd;
    page-break-inside: avoid;
  }
}

/* ==========================================
   High Contrast Mode
   ========================================== */
@media (prefers-contrast: high) {
  :root {
    --border-color: #000000;
    --text-muted: #000000;
  }
  
  [data-theme="dark"] {
    --border-color: #ffffff;
    --text-muted: #ffffff;
  }
}