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

:root {
  --primary-color: #0ea5e9;
  --primary-hover: #0284c7;
  --text-color: #1e293b;
  --text-light: #64748b;
  --bg-gradient: linear-gradient(135deg, #0ea5e9 0%, #2dd4bf 100%);
  --glass-bg: rgba(255, 255, 255, 0.25);
  --glass-border: rgba(255, 255, 255, 0.3);
  --glass-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.37);
  --radius: 16px;
  --transition: all 0.3s ease;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background: var(--bg-gradient);
  min-height: 100vh;
  color: var(--text-color);
  line-height: 1.6;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
.header {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--glass-border);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

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

.header h1 {
  font-size: 1.75rem;
  font-weight: 600;
  color: white;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

/* Main */
.main {
  padding: 2rem 0;
}

/* Resources Grid */
.resources-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.5rem;
}

.resource-card {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  box-shadow: var(--glass-shadow);
  overflow: hidden;
  transition: var(--transition);
  cursor: pointer;
}

.resource-card:hover {
  transform: translateY(-5px);
  background: rgba(255, 255, 255, 0.35);
  box-shadow: 0 12px 40px 0 rgba(31, 38, 135, 0.45);
}

.resource-card.pinned {
  border: 2px solid rgba(255, 255, 255, 0.6);
}

.resource-card.pinned::before {
  content: '⭐ 置顶';
  position: absolute;
  top: 12px;
  right: 12px;
  background: rgba(255, 255, 255, 0.9);
  color: #764ba2;
  padding: 0.3rem 0.6rem;
  border-radius: 8px;
  font-size: 0.75rem;
  font-weight: 600;
}

.resource-card {
  position: relative;
}

.resource-icon {
  height: 140px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 4rem;
  background: rgba(255, 255, 255, 0.15);
  color: white;
}

.resource-content {
  padding: 1.25rem;
}

.resource-title {
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-color);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.resource-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.5rem;
}

.resource-category {
  background: rgba(255, 255, 255, 0.4);
  padding: 0.25rem 0.6rem;
  border-radius: 8px;
  font-size: 0.8rem;
  color: var(--text-color);
}

.resource-description {
  font-size: 0.9rem;
  color: var(--text-light);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.resource-footer {
  padding: 1rem 1.25rem;
  border-top: 1px solid rgba(255, 255, 255, 0.2);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.resource-stats {
  font-size: 0.85rem;
  color: var(--text-light);
  background: rgba(255, 255, 255, 0.3);
  padding: 0.3rem 0.6rem;
  border-radius: 8px;
}

/* Modal */
.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.4);
  backdrop-filter: blur(5px);
  -webkit-backdrop-filter: blur(5px);
  z-index: 1000;
  align-items: center;
  justify-content: center;
  padding: 1rem;
}

.modal.active {
  display: flex;
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: scale(0.95); }
  to { opacity: 1; transform: scale(1); }
}

.modal-content {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-radius: 20px;
  max-width: 480px;
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
  position: relative;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

.close-btn {
  position: absolute;
  top: 1rem;
  right: 1rem;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text-light);
  transition: var(--transition);
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: rgba(0, 0, 0, 0.1);
}

.close-btn:hover {
  background: rgba(0, 0, 0, 0.2);
  color: var(--text-color);
}

.modal-body {
  padding: 2rem;
}

.modal-body h3 {
  margin-bottom: 1.5rem;
  color: var(--text-color);
  font-size: 1.4rem;
}

.detail-row {
  display: flex;
  justify-content: space-between;
  padding: 0.75rem 0;
  border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.detail-row:last-child {
  border-bottom: none;
}

.detail-label {
  color: var(--text-light);
  font-weight: 500;
}

.detail-value {
  color: var(--text-color);
  text-align: right;
  max-width: 60%;
  word-break: break-all;
  font-weight: 500;
}

.download-section {
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 2px solid rgba(0, 0, 0, 0.1);
  text-align: center;
}

.btn {
  padding: 0.875rem 2rem;
  border: none;
  border-radius: 12px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}

.btn-primary {
  background: var(--bg-gradient);
  color: white;
  box-shadow: 0 4px 15px rgba(14, 165, 233, 0.4);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(14, 165, 233, 0.5);
}

.btn-large {
  padding: 1rem 2.5rem;
  font-size: 1.1rem;
}

/* Responsive */
@media (max-width: 768px) {
  .header h1 {
    font-size: 1.4rem;
  }
  
  .resources-grid {
    grid-template-columns: 1fr;
  }
  
  .modal-body {
    padding: 1.5rem;
  }
  
  .detail-row {
    flex-direction: column;
    gap: 0.25rem;
  }
  
  .detail-value {
    max-width: 100%;
    text-align: left;
  }
}

/* Loading */
.loading {
  text-align: center;
  padding: 4rem;
  color: white;
  font-size: 1.1rem;
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  border-radius: var(--radius);
}

.loading::after {
  content: '';
  display: inline-block;
  width: 24px;
  height: 24px;
  border: 3px solid rgba(255, 255, 255, 0.3);
  border-top-color: white;
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin-left: 0.75rem;
  vertical-align: middle;
}

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

/* Empty State */
.empty-state {
  text-align: center;
  padding: 4rem;
  color: white;
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  border-radius: var(--radius);
}

.empty-state-icon {
  font-size: 4rem;
  margin-bottom: 1rem;
  opacity: 0.8;
}