:root {
  --primary: #4f46e5;
  --primary-hover: #4338ca;
  --bg: #0f172a;
  --card-bg: rgba(30, 41, 59, 0.7);
  --text: #f8fafc;
  --text-muted: #94a3b8;
  --accent: #38bdf8;
  --success: #10b981;
  --error: #ef4444;
  --radius: 12px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
}

body {
  background-color: var(--bg);
  background-image: 
    radial-gradient(at 0% 0%, rgba(79, 70, 229, 0.15) 0px, transparent 50%),
    radial-gradient(at 100% 100%, rgba(56, 189, 248, 0.1) 0px, transparent 50%);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 2rem;
}

.container {
  width: 100%;
  max-width: 900px;
  background: var(--card-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 24px;
  padding: 3rem;
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
  animation: fadeIn 0.6s ease-out;
}

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

header {
  text-align: center;
  margin-bottom: 3rem;
}

h1 {
  font-size: 2.5rem;
  font-weight: 800;
  background: linear-gradient(135deg, #fff 0%, #94a3b8 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 0.5rem;
}

p.subtitle {
  color: var(--text-muted);
  font-size: 1.1rem;
}

/* Upload Section */
.upload-zone {
  border: 2px dashed rgba(255, 255, 255, 0.1);
  border-radius: var(--radius);
  padding: 3rem;
  text-align: center;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
  margin-bottom: 3rem;
  position: relative;
  overflow: hidden;
}

.upload-zone:hover, .upload-zone.dragover {
  border-color: var(--primary);
  background: rgba(79, 70, 229, 0.05);
}

.upload-zone i {
  font-size: 3rem;
  color: var(--primary);
  margin-bottom: 1rem;
  display: block;
}

.upload-zone p {
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

.btn-upload {
  background: var(--primary);
  color: white;
  padding: 0.75rem 2rem;
  border-radius: 8px;
  border: none;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}

.btn-upload:hover {
  background: var(--primary-hover);
  transform: translateY(-2px);
}

/* Tabs */
.tabs {
  display: flex;
  gap: 1rem;
  margin-bottom: 2rem;
  justify-content: center;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  padding-bottom: 1.5rem;
}

.tab-btn {
  background: transparent;
  color: var(--text-muted);
  border: none;
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  border-radius: 12px;
  transition: all 0.2s;
}

.tab-btn:hover {
  color: var(--text);
  background: rgba(255, 255, 255, 0.05);
}

.tab-btn.active {
  color: var(--text);
  background: var(--primary);
  box-shadow: 0 4px 15px -1px rgba(79, 70, 229, 0.3);
}

.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
}

#fileInput, #folderInput {
  display: none;
}

/* Files Table */
.file-list-container {
  margin-top: 2rem;
}

.file-list-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
}

.file-list-header h2 {
  font-size: 1.25rem;
  color: var(--text);
}

.file-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.file-item {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: 12px;
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: all 0.2s;
  animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
  from { opacity: 0; transform: translateX(-10px); }
  to { opacity: 1; transform: translateX(0); }
}

.file-item:hover {
  background: rgba(255, 255, 255, 0.05);
  border-color: rgba(255, 255, 255, 0.1);
  transform: scale(1.01);
}

.file-info {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.file-icon {
  width: 40px;
  height: 40px;
  background: rgba(79, 70, 229, 0.1);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
}

.file-details h3 {
  font-size: 0.95rem;
  font-weight: 500;
  margin-bottom: 0.25rem;
  max-width: 300px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.file-details span {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.file-actions {
  display: flex;
  gap: 0.75rem;
}

.btn-download {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text);
  padding: 0.5rem 1rem;
  border-radius: 8px;
  border: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 0.85rem;
  text-decoration: none;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

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

/* Progress bar */
.progress-container {
  display: none;
  width: 100%;
  height: 4px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 2px;
  margin-top: 1rem;
}

.progress-bar {
  height: 100%;
  background: var(--primary);
  width: 0%;
  transition: width 0.3s;
  border-radius: 2px;
}

/* Empty state */
.empty-state {
  text-align: center;
  padding: 2rem;
  color: var(--text-muted);
}

/* Notification styling if needed */
.toast {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: var(--primary);
  color: white;
  padding: 1rem 1.5rem;
  border-radius: 12px;
  box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.3);
  display: none;
  z-index: 1000;
  animation: slideBottom 0.3s ease-out;
}

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