:root {
  --bg-primary: #0a0a0b;
  --bg-secondary: #121214;
  --bg-tertiary: #1c1c1f;
  --border-color: #27272a;
  --border-hover: #3f3f46;
  --text-primary: #fafafa;
  --text-secondary: #a1a1aa;
  --text-tertiary: #71717a;
  --accent-primary: #8b5cf6;
  --accent-secondary: #a78bfa;
  --accent-glow: rgba(139, 92, 246, 0.4);
  --success: #10b981;
  --success-bg: rgba(16, 185, 129, 0.15);
  --danger: #ef4444;
  --danger-bg: rgba(239, 68, 68, 0.15);
  --warning: #f59e0b;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);
  --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --font-sans: "Figtree", system-ui, sans-serif;
  --font-mono: "Space Mono", monospace;
  --sidebar-width: 340px;
}

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

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  height: 100vh;
  overflow: hidden;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.app {
  display: flex;
  flex-direction: column;
  height: 100vh;
  max-width: 1800px;
  margin: 0 auto;
  width: 100%;
}

.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 28px;
  height: 68px;
  background: linear-gradient(
    180deg,
    var(--bg-secondary) 0%,
    rgba(18, 18, 20, 0.95) 100%
  );
  border-bottom: 1px solid var(--border-color);
  gap: 24px;
  flex-shrink: 0;
  backdrop-filter: blur(12px);
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-shrink: 0;
}

.brand-icon {
  width: 40px;
  height: 40px;
  background: linear-gradient(
    135deg,
    var(--accent-primary),
    var(--accent-secondary)
  );
  border-radius: var(--radius-md);
  display: grid;
  place-items: center;
  font-size: 22px;
  box-shadow: 0 4px 16px var(--accent-glow);
  position: relative;
  overflow: hidden;
}

.brand-icon::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, transparent, rgba(255, 255, 255, 0.2));
}

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.brand-title {
  font-size: 1.25rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  background: linear-gradient(
    135deg,
    var(--text-primary),
    var(--text-secondary)
  );
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.brand-tagline {
  font-size: 0.75rem;
  color: var(--text-tertiary);
  font-weight: 500;
}

.header-center {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: center;
}

.privacy-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  background: var(--success-bg);
  border: 1px solid rgba(16, 185, 129, 0.3);
  border-radius: 20px;
  font-size: 0.8rem;
  color: var(--success);
  font-weight: 600;
  box-shadow: 0 2px 8px rgba(16, 185, 129, 0.15);
}

.privacy-badge svg {
  width: 16px;
  height: 16px;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 0.875rem;
  font-weight: 600;
  font-family: var(--font-sans);
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.08), transparent);
  opacity: 0;
  transition: opacity 0.2s;
}

.btn:hover::before {
  opacity: 1;
}

.btn:hover:not(:disabled) {
  background: var(--border-color);
  border-color: var(--border-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn:active:not(:disabled) {
  transform: translateY(0);
}

.btn-primary {
  background: linear-gradient(
    135deg,
    var(--accent-primary),
    var(--accent-secondary)
  );
  border: none;
  color: white;
  box-shadow: 0 2px 12px var(--accent-glow);
}

.btn-primary:hover:not(:disabled) {
  background: linear-gradient(
    135deg,
    var(--accent-secondary),
    var(--accent-primary)
  );
  box-shadow: 0 4px 20px var(--accent-glow);
}

.btn-danger {
  color: var(--danger);
  border-color: rgba(239, 68, 68, 0.3);
  background: var(--danger-bg);
}

.btn-danger:hover:not(:disabled) {
  background: var(--danger);
  color: white;
  border-color: var(--danger);
  box-shadow: 0 4px 12px rgba(239, 68, 68, 0.3);
}

.btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none !important;
}

.btn svg {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

.main {
  display: flex;
  flex: 1;
  overflow: hidden;
  background: var(--bg-primary);
}

.sidebar {
  width: var(--sidebar-width);
  min-width: 280px;
  max-width: 500px;
  background: var(--bg-secondary);
  display: flex;
  flex-direction: column;
  border-right: 1px solid var(--border-color);
  flex-shrink: 0;
}

.sidebar-header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--bg-tertiary);
}

.sidebar-title {
  font-weight: 700;
  font-size: 0.875rem;
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-primary);
}

.sidebar-actions {
  display: flex;
  gap: 6px;
}

.btn-icon {
  padding: 8px;
  min-width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  display: grid;
  place-items: center;
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  cursor: pointer;
  transition: var(--transition);
}

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

.btn-icon.active {
  color: var(--accent-primary);
  border-color: var(--accent-primary);
  background: rgba(139, 92, 246, 0.1);
}

.btn-icon svg {
  width: 16px;
  height: 16px;
}

.sidebar-stats {
  padding: 12px 20px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  gap: 16px;
  font-size: 0.8rem;
  color: var(--text-tertiary);
  font-family: var(--font-mono);
  background: var(--bg-secondary);
}

.stat-item {
  display: flex;
  align-items: center;
  gap: 6px;
}

.stat-value {
  color: var(--text-primary);
  font-weight: 700;
}

.tree-container {
  flex: 1;
  overflow-y: auto;
  padding: 8px;
}

.tree-container::-webkit-scrollbar {
  width: 6px;
}

.tree-container::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 3px;
}

.tree-container::-webkit-scrollbar-track {
  background: transparent;
}

.empty-state {
  text-align: center;
  padding: 60px 24px;
  color: var(--text-tertiary);
}

.empty-state-icon {
  font-size: 3rem;
  margin-bottom: 16px;
  opacity: 0.4;
}

.empty-state-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

.empty-state-desc {
  font-size: 0.8rem;
  opacity: 0.8;
}

.tree {
  font-size: 0.825rem;
  font-family: var(--font-sans);
}

.tree-node {
  user-select: none;
}

.tree-toggle {
  width: 20px;
  height: 20px;
  display: grid;
  place-items: center;
  font-size: 0.6rem;
  color: var(--text-tertiary);
  transition: var(--transition);
  flex-shrink: 0;
  cursor: pointer;
  border-radius: 4px;
}

.tree-toggle:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

.tree-toggle.collapsed {
  transform: rotate(-90deg);
}

.tree-row {
  display: flex;
  align-items: center;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  gap: 8px;
  transition: var(--transition);
}

.tree-row:hover {
  background: var(--bg-tertiary);
}

.tree-row.folder {
  font-weight: 600;
}

.tree-icon {
  font-size: 1rem;
  flex-shrink: 0;
  width: 18px;
  text-align: center;
}

.tree-icon.folder {
  color: var(--warning);
}

.tree-icon.file {
  color: var(--text-tertiary);
}

.tree-label {
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.tree-meta {
  font-size: 0.7rem;
  color: var(--text-tertiary);
  font-family: var(--font-mono);
  flex-shrink: 0;
  margin-left: 8px;
}

.tree-remove {
  width: 22px;
  height: 22px;
  display: grid;
  place-items: center;
  border-radius: 6px;
  font-size: 0.9rem;
  color: var(--text-tertiary);
  opacity: 0;
  transition: var(--transition);
  background: transparent;
  border: none;
  cursor: pointer;
  flex-shrink: 0;
}

.tree-row:hover .tree-remove {
  opacity: 1;
}

.tree-remove:hover {
  background: var(--danger);
  color: white;
}

.tree-children {
  margin-left: 24px;
  border-left: 1px dashed var(--border-color);
  padding-left: 4px;
}

.tree-children.collapsed {
  display: none;
}

.resize-handle {
  width: 4px;
  background: transparent;
  cursor: col-resize;
  position: relative;
  flex-shrink: 0;
  z-index: 20;
  transition: background 0.2s;
}

.resize-handle::after {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  width: 1px;
  background: var(--border-color);
  transition: background 0.2s;
}

.resize-handle:hover::after,
.resize-handle.resizing::after {
  background: var(--accent-primary);
}

.resize-handle:hover {
  background: rgba(139, 92, 246, 0.1);
}

.content {
  flex: 1;
  display: flex;
  flex-direction: column;
  background: var(--bg-primary);
  position: relative;
  overflow: hidden;
}

.drop-zone {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 40px;
  margin: 24px;
  border: 2px dashed var(--border-color);
  border-radius: var(--radius-xl);
  background: var(--bg-secondary);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.drop-zone::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(
    800px circle at var(--x, 50%) var(--y, 50%),
    rgba(139, 92, 246, 0.1),
    transparent 40%
  );
  opacity: 0;
  transition: opacity 0.3s;
  pointer-events: none;
}

.drop-zone.drag-over {
  border-color: var(--accent-primary);
  background: rgba(139, 92, 246, 0.05);
}

.drop-zone.drag-over::before {
  opacity: 1;
}

.drop-zone.has-files {
  opacity: 0.5;
  border-style: solid;
}

.drop-content {
  text-align: center;
  max-width: 420px;
  z-index: 1;
  pointer-events: none;
}

.drop-icon {
  font-size: 4rem;
  margin-bottom: 20px;
  opacity: 0.6;
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%,
  100% {
    transform: translateY(0);
  }

  50% {
    transform: translateY(-10px);
  }
}

.drop-title {
  font-size: 1.5rem;
  font-weight: 800;
  margin-bottom: 10px;
  letter-spacing: -0.02em;
}

.drop-hint {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.drop-hint code {
  background: var(--bg-tertiary);
  padding: 3px 8px;
  border-radius: 6px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  border: 1px solid var(--border-color);
}

.drop-hint .highlight {
  color: var(--accent-secondary);
  font-weight: 600;
}

.file-list-container {
  flex: 1;
  overflow-y: auto;
  padding: 20px 24px;
  display: none;
}

.file-list-container.active {
  display: block;
}

.file-list-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-color);
}

.file-list-title {
  font-weight: 700;
  font-size: 0.95rem;
  display: flex;
  align-items: center;
  gap: 8px;
}

.file-list-count {
  font-size: 0.8rem;
  color: var(--text-tertiary);
  font-family: var(--font-mono);
  background: var(--bg-tertiary);
  padding: 4px 10px;
  border-radius: 12px;
}

.file-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.file-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  font-size: 0.85rem;
  transition: var(--transition);
  animation: slideIn 0.25s ease;
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateX(-12px);
  }

  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.file-item:hover {
  border-color: var(--border-hover);
  transform: translateX(4px);
  background: var(--bg-tertiary);
}

.file-item-icon {
  font-size: 1.1rem;
  flex-shrink: 0;
}

.file-item-path {
  flex: 1;
  font-family: var(--font-mono);
  color: var(--text-secondary);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-size: 0.825rem;
}

.file-item-size {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-tertiary);
  flex-shrink: 0;
  min-width: 60px;
  text-align: right;
  background: var(--bg-tertiary);
  padding: 3px 8px;
  border-radius: 6px;
}

.file-item-remove {
  width: 26px;
  height: 26px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  font-size: 0.9rem;
  color: var(--text-tertiary);
  background: transparent;
  border: none;
  cursor: pointer;
  transition: var(--transition);
  flex-shrink: 0;
}

.file-item-remove:hover {
  background: var(--danger);
  color: white;
}

.loading-overlay {
  position: absolute;
  inset: 0;
  background: rgba(10, 10, 11, 0.95);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 50;
  backdrop-filter: blur(8px);
  opacity: 0;
  visibility: hidden;
  transition: all 0.25s;
  gap: 16px;
}

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

.loader {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  width: 100%;
  max-width: 320px;
}

.spinner {
  width: 36px;
  height: 36px;
  border: 3px solid var(--border-color);
  border-top-color: var(--accent-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

.loader-text {
  font-size: 0.9rem;
  color: var(--text-secondary);
  font-weight: 500;
  text-align: center;
}

.progress-container {
  width: 100%;
  height: 6px;
  background: var(--bg-tertiary);
  border-radius: 3px;
  overflow: hidden;
  margin-top: 4px;
}

.progress-bar {
  height: 100%;
  background: linear-gradient(
    90deg,
    var(--accent-primary),
    var(--accent-secondary)
  );
  width: 0%;
  transition: width 0.15s ease;
  border-radius: 3px;
}

.cancel-btn {
  margin-top: 8px;
  padding: 6px 16px;
  background: var(--danger-bg);
  color: var(--danger);
  border: 1px solid var(--danger);
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  cursor: pointer;
  transition: var(--transition);
}

.cancel-btn:hover {
  background: var(--danger);
  color: white;
}

.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  z-index: 300;
  pointer-events: none;
}

.toast {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 20px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  font-size: 0.875rem;
  color: var(--text-primary);
  box-shadow: var(--shadow-lg);
  animation:
    toastIn 0.3s ease,
    toastOut 0.3s ease 2.7s forwards;
  pointer-events: auto;
  max-width: 420px;
  backdrop-filter: blur(12px);
}

@keyframes toastIn {
  from {
    opacity: 0;
    transform: translateY(12px) scale(0.96);
  }

  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

@keyframes toastOut {
  to {
    opacity: 0;
    transform: translateY(-12px) scale(0.96);
  }
}

.toast.success {
  border-color: var(--success);
  background: var(--success-bg);
}

.toast.error {
  border-color: var(--danger);
  background: var(--danger-bg);
}

.toast-icon {
  font-size: 1.25rem;
  flex-shrink: 0;
}

.toast-content {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.toast-title {
  font-weight: 700;
  font-size: 0.9rem;
}

.toast-desc {
  font-size: 0.825rem;
  color: var(--text-secondary);
}

.footer-hint {
  text-align: center;
  padding: 12px 20px;
  font-size: 0.775rem;
  color: var(--text-tertiary);
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  font-family: var(--font-mono);
  flex-shrink: 0;
}

.footer-hint kbd {
  background: var(--bg-tertiary);
  padding: 3px 8px;
  border-radius: 6px;
  border: 1px solid var(--border-color);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  margin: 0 2px;
}

.hidden-input {
  display: none;
}

@media (max-width: 1100px) {
  .header {
    flex-wrap: wrap;
    height: auto;
    padding: 16px 20px;
    gap: 16px;
  }

  .brand {
    min-width: 100%;
  }

  .header-center {
    min-width: 100%;
  }

  .header-actions {
    min-width: 100%;
    justify-content: center;
    flex-wrap: wrap;
  }
}

@media (max-width: 900px) {
  .main {
    flex-direction: column;
  }

  .sidebar {
    width: 100% !important;
    max-width: 100% !important;
    max-height: 40vh;
    border-right: none;
    border-bottom: 1px solid var(--border-color);
  }

  .resize-handle {
    display: none;
  }
}