/* 
 * Design Tokens & Reset
 */
:root {
  /* Color Palette */
  --color-bg: #f3f4f6; /* Light gray background */
  --color-surface: #ffffff;
  --color-primary: #4f46e5; /* Indigo */
  --color-primary-hover: #4338ca;
  --color-text-primary: #111827;
  --color-text-secondary: #4b5563;
  --color-text-tertiary: #9ca3af;
  --color-border: #e5e7eb;
  
  /* Type Info Colors */
  --color-type-youtube: #ef4444;
  --color-type-article: #10b981;
  --color-type-pdf: #f59e0b;

  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --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);
  
  /* Radius */
  --radius-md: 0.5rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
}

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

body {
  font-family: var(--font-family);
  background-color: var(--color-bg);
  color: var(--color-text-primary);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

input, textarea {
  font-family: inherit;
}

a {
  text-decoration: none;
  color: inherit;
}

/* App Container */
.app-container {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Header */
.header {
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: sticky;
  top: 0;
  z-index: 10;
  box-shadow: var(--shadow-sm);
}

.header-logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--color-primary);
}

/* Primary Button */
.btn-primary {
  background-color: var(--color-primary);
  color: white;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-md);
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: background-color var(--transition-fast);
}

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

/* Main Content Area */
.main-content {
  flex: 1;
  padding: 2rem;
  max-width: 1600px;
  margin: 0 auto;
  width: 100%;
}

/* Board Grid */
.board-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.5rem;
  align-items: start;
}

/* Resource Card */
.resource-card {
  background-color: var(--color-surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
  border: 1px solid var(--color-border);
  cursor: pointer;
  display: flex;
  flex-direction: column;
}

.resource-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.card-media {
  width: 100%;
  height: 180px;
  background-color: var(--color-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.card-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.card-media iframe {
  width: 100%;
  height: 100%;
  border: none;
  pointer-events: none; /* Let card handle clicks */
}

/* Fallback icons for no media */
.card-media-placeholder {
  color: var(--color-text-tertiary);
}
.card-media-placeholder .material-symbols-outlined {
  font-size: 3rem;
}

.card-type-badge {
  position: absolute;
  top: 0.75rem;
  right: 0.75rem;
  padding: 0.25rem 0.75rem;
  border-radius: 999px;
  font-size: 0.75rem;
  font-weight: 600;
  color: white;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  z-index: 2;
  box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.badge-youtube { background-color: var(--color-type-youtube); }
.badge-article { background-color: var(--color-type-article); }
.badge-pdf { background-color: var(--color-type-pdf); }

.card-content {
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.card-title {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--color-text-primary);
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-description {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  margin-bottom: 1rem;
  flex: 1;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: auto;
  padding-top: 1rem;
  border-top: 1px solid var(--color-border);
  font-size: 0.85rem;
  color: var(--color-text-tertiary);
}

.card-meta {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.card-action {
  color: var(--color-text-secondary);
  display: flex;
  align-items: center;
  gap: 0.25rem;
  transition: color var(--transition-fast);
}
.card-action:hover {
  color: var(--color-primary);
}
.card-action .material-symbols-outlined {
  font-size: 1.1rem;
}

/* Modal Overlay (Glassmorphism) */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-color: rgba(17, 24, 39, 0.4);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  padding: 1rem;
}

/* Form Container */
.form-container {
  background-color: var(--color-surface);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  width: 100%;
  max-width: 500px;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  animation: slideUp 0.3s ease-out;
}

@keyframes slideUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.form-header {
  padding: 1.5rem;
  border-bottom: 1px solid var(--color-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.form-title {
  font-size: 1.25rem;
  font-weight: 600;
}

.close-btn {
  color: var(--color-text-tertiary);
  transition: color var(--transition-fast);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0.25rem;
  border-radius: var(--radius-md);
}
.close-btn:hover {
  color: var(--color-text-primary);
  background-color: var(--color-bg);
}

.form-body {
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.form-label {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-secondary);
}

.form-input, .form-textarea, .form-select {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 0.95rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background-color: var(--color-surface);
  color: var(--color-text-primary);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input:focus, .form-textarea:focus, .form-select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.form-textarea {
  resize: vertical;
  min-height: 100px;
}

.form-footer {
  padding: 1.25rem 1.5rem;
  background-color: var(--color-bg);
  border-top: 1px solid var(--color-border);
  display: flex;
  justify-content: flex-end;
  gap: 0.75rem;
}

.btn-secondary {
  background-color: white;
  color: var(--color-text-primary);
  border: 1px solid var(--color-border);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-md);
  font-weight: 500;
  transition: all var(--transition-fast);
}

.btn-secondary:hover {
  background-color: var(--color-bg);
  border-color: var(--color-text-tertiary);
}

/* Detail View Modal (Expanded Card View) */
.detail-container {
  max-width: 800px;
  width: 100%;
  max-height: 90vh;
  display: flex;
  flex-direction: column;
}

.detail-body {
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}

.detail-media {
  width: 100%;
  background-color: #000;
  display: flex;
  justify-content: center;
}

.detail-media iframe, .detail-media img {
  width: 100%;
  max-height: 450px;
  object-fit: contain;
}

.detail-info {
  padding: 1.5rem;
}

/* Comments Section */
.comments-section {
  padding: 0 1.5rem 1.5rem;
  border-top: 1px solid var(--color-border);
  display: flex;
  flex-direction: column;
  gap: 1rem;
}
.comments-header {
  font-size: 1.1rem;
  font-weight: 600;
  margin-top: 1.5rem;
  margin-bottom: 0.5rem;
}

.comment-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  max-height: 250px;
  overflow-y: auto;
  padding-right: 0.5rem;
}

.comment-item {
  background-color: var(--color-bg);
  padding: 1rem;
  border-radius: var(--radius-md);
}

.comment-author {
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--color-text-primary);
  display: flex;
  justify-content: space-between;
}
.comment-time {
  font-weight: 400;
  color: var(--color-text-tertiary);
  font-size: 0.8rem;
}

.comment-text {
  margin-top: 0.5rem;
  font-size: 0.95rem;
  color: var(--color-text-secondary);
}

.comment-form {
  display: flex;
  gap: 0.75rem;
  margin-top: 0.5rem;
}
.comment-form input {
  flex: 1;
}

/* Responsiveness */
@media (max-width: 768px) {
  .board-grid {
    grid-template-columns: 1fr;
  }
  
  .header {
    padding: 1rem;
  }
  
  .main-content {
    padding: 1rem;
  }
  
  .detail-container {
    height: 100vh;
    max-height: 100vh;
    border-radius: 0;
  }
  
  .form-container {
    max-height: 90vh;
    overflow-y: auto;
  }
}