:root {
  --primary-color: #6366f1;
  --primary-dark: #4f46e5;
  --primary-light: #818cf8;
  --bg-dark: #0f172a;
  --bg-card: #1e293b;
  --bg-card-hover: #334155;
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --border-color: #334155;
  --shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
  --shadow-hover: 0 20px 50px rgba(99, 102, 241, 0.2);
}

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

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: var(--bg-dark);
  color: var(--text-primary);
  min-height: 100vh;
}

.container {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.header {
  background: linear-gradient(135deg, var(--bg-card) 0%, var(--bg-dark) 100%);
  padding: 1.5rem 2rem;
  border-bottom: 1px solid var(--border-color);
  backdrop-filter: blur(10px);
}

.header-content {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.5rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--primary-light), var(--primary-color));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.logo i {
  color: var(--primary-light);
  font-size: 1.75rem;
}

.header-info {
  display: flex;
  gap: 2rem;
}

.file-count {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.file-count i {
  color: var(--primary-light);
}

.breadcrumb {
  padding: 1rem 2rem;
  background: var(--bg-dark);
  border-bottom: 1px solid var(--border-color);
}

.back-btn {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  background: var(--bg-card);
  color: var(--text-primary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s ease;
  font-size: 1rem;
}

.back-btn:hover:not(:disabled) {
  background: var(--bg-card-hover);
  border-color: var(--primary-color);
  color: var(--primary-light);
}

.back-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.breadcrumb-items {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.breadcrumb-item {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.5rem 1rem;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.3s ease;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.breadcrumb-item:hover {
  background: var(--bg-card);
  color: var(--text-primary);
}

.breadcrumb-item:last-child {
  background: var(--bg-card);
  color: var(--text-primary);
}

.breadcrumb-item:not(:last-child)::after {
  content: '/';
  margin-left: 0.5rem;
  color: var(--text-secondary);
}

.main-content {
  flex: 1;
  padding: 2rem;
}

.file-grid {
  max-width: 1400px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
}

.file-card {
  background: var(--bg-card);
  border-radius: 16px;
  padding: 1.5rem;
  cursor: pointer;
  transition: all 0.3s ease;
  border: 1px solid var(--border-color);
  position: relative;
  overflow: hidden;
}

.file-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary-color), var(--primary-light));
  transform: scaleX(0);
  transition: transform 0.3s ease;
}

.file-card:hover::before {
  transform: scaleX(1);
}

.file-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-hover);
  border-color: var(--primary-color);
}

.file-icon {
  width: 50px;
  height: 50px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
  font-size: 1.75rem;
  transition: all 0.3s ease;
}

.folder-icon {
  background: linear-gradient(135deg, #f59e0b, #d97706);
  color: white;
}

.file-card:hover .folder-icon {
  transform: scale(1.1);
}

.file-icon-file {
  background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
  color: white;
}

.file-icon-custom {
  color: white;
}

.file-card:hover .file-icon-file {
  transform: scale(1.1);
}

.file-name {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.file-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.file-size, .file-modified {
  display: flex;
  align-items: center;
  gap: 0.3rem;
}

.download-btn {
  position: absolute;
  top: 1rem;
  right: 1rem;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--bg-card-hover);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: all 0.3s ease;
  color: var(--primary-light);
}

.file-card:hover .download-btn {
  opacity: 1;
}

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

.preview-btn {
  position: absolute;
  top: 1rem;
  right: 4rem;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--bg-card-hover);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: all 0.3s ease;
  color: #22d3ee;
}

.file-card:hover .preview-btn {
  opacity: 1;
}

.preview-btn:hover {
  background: #0891b2;
  color: white;
}

.preview-tooltip {
  position: fixed;
  transform: translateX(-50%);
  background: linear-gradient(135deg, #dc2626, #b91c1c);
  color: white;
  padding: 6px 12px;
  border-radius: 6px;
  font-size: 0.8rem;
  white-space: nowrap;
  box-shadow: 0 4px 12px rgba(220, 38, 38, 0.4);
  z-index: 9999;
  animation: tooltipFadeIn 0.2s ease;
}

.preview-tooltip::after {
  content: '';
  position: absolute;
  bottom: -6px;
  left: 50%;
  transform: translateX(-50%);
  border-left: 6px solid transparent;
  border-right: 6px solid transparent;
  border-top: 6px solid #dc2626;
}

@keyframes tooltipFadeIn {
  from {
    opacity: 0;
    transform: translateX(-50%) translateY(-5px);
  }
  to {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
  }
}

.empty-state {
  max-width: 400px;
  margin: 4rem auto;
  text-align: center;
  padding: 3rem;
  background: var(--bg-card);
  border-radius: 16px;
  border: 1px solid var(--border-color);
}

.empty-state i {
  font-size: 4rem;
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.empty-state p {
  color: var(--text-secondary);
  font-size: 1rem;
}

.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(15, 23, 42, 0.8);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  display: none;
}

.loading-overlay.active {
  display: flex;
}

.loading-spinner {
  width: 60px;
  height: 60px;
}

.spinner {
  width: 100%;
  height: 100%;
  border: 3px solid var(--border-color);
  border-top-color: var(--primary-color);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

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

@media (max-width: 768px) {
  .file-grid {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
  }
  
  .file-card {
    display: flex;
    align-items: center;
    padding: 1rem;
    border-radius: 12px;
    position: relative;
    overflow: visible;
  }
  
  .file-card::before {
    display: none;
  }
  
  .file-card:hover {
    transform: none;
    box-shadow: none;
  }
  
  .file-icon {
    width: 44px;
    height: 44px;
    flex-shrink: 0;
    margin-bottom: 0;
    margin-right: 1rem;
  }
  
  .file-card-content {
    flex: 1;
    min-width: 0;
  }
  
  .file-name {
    margin-bottom: 0.25rem;
    font-size: 0.95rem;
  }
  
  .file-meta {
    font-size: 0.75rem;
  }
  
  .download-btn,
  .preview-btn {
    position: static;
    opacity: 1;
    width: 36px;
    height: 36px;
    margin-left: 0.5rem;
    flex-shrink: 0;
  }
  
  .download-btn {
    background: var(--primary-color);
    color: white;
  }
  
  .download-btn:hover {
    background: var(--primary-dark);
  }
  
  .preview-btn {
    display: none;
  }
  
  .btn-actions {
    display: flex;
    gap: 0.5rem;
    margin-left: auto;
  }
  
  .header {
    padding: 1rem;
  }
  
  .header-content {
    flex-direction: column;
    gap: 1rem;
  }
  
  .breadcrumb {
    padding: 0.75rem 1rem;
  }
  
  .main-content {
    padding: 1rem;
  }
}

.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(15, 23, 42, 0.9);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 2000;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
}

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

.modal-content {
  background: var(--bg-card);
  border-radius: 16px;
  width: 90%;
  max-width: 700px;
  max-height: 80vh;
  overflow: hidden;
  transform: scale(0.9);
  transition: transform 0.3s ease;
}

.modal-overlay.active .modal-content {
  transform: scale(1);
}

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

.modal-title {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
}

.modal-title i {
  color: var(--primary-light);
}

.modal-close {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s ease;
}

.modal-close:hover {
  background: var(--bg-card-hover);
  color: var(--text-primary);
}

.modal-body {
  padding: 1.5rem;
  max-height: 50vh;
  overflow-y: auto;
}

.preview-stats {
  display: flex;
  gap: 2rem;
  margin-bottom: 1rem;
  padding: 1rem;
  background: var(--bg-dark);
  border-radius: 8px;
}

.preview-comment {
  margin-bottom: 1.5rem;
  padding: 1rem;
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.1), rgba(99, 102, 241, 0.05));
  border: 1px solid rgba(99, 102, 241, 0.2);
  border-radius: 8px;
}

.comment-header {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--primary-light);
  margin-bottom: 0.5rem;
}

.comment-content {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.stat-item {
  display: flex;
  flex-direction: column;
}

.stat-label {
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-bottom: 0.25rem;
}

.stat-value {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
}

.preview-list {
  background: var(--bg-dark);
  border-radius: 8px;
  overflow: hidden;
}

.preview-item {
  display: flex;
  align-items: center;
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--border-color);
  gap: 0.75rem;
}

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

.preview-item.header {
  background: var(--bg-card-hover);
  font-weight: 600;
  color: var(--text-secondary);
  font-size: 0.85rem;
}

.preview-item.header .name {
  flex: 2;
}

.preview-item.header .size,
.preview-item.header .original-size {
  flex: 1;
  text-align: right;
}

.preview-item.header .comment {
  flex: 1.5;
  text-align: right;
}

.preview-item .name {
  flex: 2;
  color: var(--text-primary);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.preview-item .size,
.preview-item .original-size {
  flex: 1;
  text-align: right;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.preview-item .comment {
  flex: 1.5;
  text-align: right;
  color: var(--text-secondary);
  font-size: 0.85rem;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.preview-item .icon {
  width: 24px;
  height: 24px;
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  color: white;
}

.preview-item .icon.folder {
  background: linear-gradient(135deg, #f59e0b, #d97706);
}

.preview-item .icon.file {
  background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
}

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

.btn {
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  font-size: 0.95rem;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: all 0.3s ease;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
  color: white;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(99, 102, 241, 0.4);
}

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

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