:root {
  --bg-primary: #0f172a;
  --bg-surface: #1e293b;
  --bg-surface-hover: #334155;
  --bg-surface-active: #475569;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent: #3b82f6;
  --accent-hover: #2563eb;
  --accent-light: rgba(59, 130, 246, 0.15);
  --border: #334155;
  --border-focus: #60a5fa;
  --canvas-bg: #111827;
  --danger: #ef4444;
  --success: #10b981;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.2);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -2px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -4px rgba(0, 0, 0, 0.4);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
}

[data-theme="light"] {
  --bg-primary: #f8fafc;
  --bg-surface: #ffffff;
  --bg-surface-hover: #f1f5f9;
  --bg-surface-active: #e2e8f0;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --accent-light: rgba(37, 99, 235, 0.1);
  --border: #e2e8f0;
  --border-focus: #3b82f6;
  --canvas-bg: #ffffff;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  height: 100vh;
  width: 100vw;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

/* Header */
.app-header {
  height: 56px;
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px;
  z-index: 20;
  flex-shrink: 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 600;
  font-size: 1.05rem;
}

.brand svg {
  color: var(--accent);
}

.file-badge {
  font-size: 0.82rem;
  color: var(--text-secondary);
  background: var(--bg-primary);
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  max-width: 250px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 7px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  font-weight: 500;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all 0.15s ease;
  user-select: none;
  text-decoration: none;
}

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

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

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

.btn-secondary:hover {
  background: var(--bg-surface-active);
}

.btn-icon {
  padding: 7px 9px;
  color: var(--text-secondary);
}

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

/* Main Area */
.app-main {
  flex: 1;
  position: relative;
  overflow: hidden;
  display: flex;
}

/* Canvas Container */
#canvas-container {
  flex: 1;
  height: 100%;
  width: 100%;
  background-color: var(--canvas-bg);
  position: relative;
  outline: none;
}

/* Uploader Screen */
.uploader-overlay {
  position: absolute;
  inset: 0;
  background: var(--bg-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 10;
  padding: 24px;
}

.uploader-card {
  max-width: 560px;
  width: 100%;
  background: var(--bg-surface);
  border: 2px dashed var(--border);
  border-radius: var(--radius-lg);
  padding: 48px 36px;
  text-align: center;
  transition: all 0.2s ease;
  cursor: pointer;
}

.uploader-card:hover,
.uploader-card.drag-over {
  border-color: var(--accent);
  background: var(--accent-light);
  transform: translateY(-2px);
}

.upload-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto 20px;
  color: var(--accent);
}

.uploader-card h2 {
  font-size: 1.5rem;
  margin-bottom: 8px;
  font-weight: 600;
}

.uploader-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 24px;
}

.uploader-buttons {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 20px;
}

.upload-hint {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* Viewport Controls */
.view-controls {
  position: absolute;
  top: 16px;
  left: 16px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 4px;
  box-shadow: var(--shadow-md);
  z-index: 5;
}

.ctrl-btn {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  width: 34px;
  height: 34px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.15s;
}

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

/* Layers Drawer */
.layers-toggle {
  position: absolute;
  top: 16px;
  right: 16px;
  z-index: 5;
  background: var(--bg-surface);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-md);
}

.layers-panel {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  width: 320px;
  background: var(--bg-surface);
  border-left: 1px solid var(--border);
  z-index: 15;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-lg);
  transform: translateX(100%);
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.layers-panel.open {
  transform: translateX(0);
}

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

.layers-header h3 {
  font-size: 1rem;
  font-weight: 600;
}

.layers-actions {
  display: flex;
  gap: 8px;
  padding: 10px 16px;
  border-bottom: 1px solid var(--border);
  background: var(--bg-primary);
}

.layer-search {
  width: 100%;
  padding: 6px 10px;
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 0.85rem;
}

.layers-list {
  flex: 1;
  overflow-y: auto;
  padding: 8px 0;
}

.layer-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 8px 16px;
  cursor: pointer;
  user-select: none;
  font-size: 0.88rem;
  transition: background 0.1s;
}

.layer-item:hover {
  background: var(--bg-surface-hover);
}

.layer-color-dot {
  width: 14px;
  height: 14px;
  border-radius: 3px;
  flex-shrink: 0;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.layer-name {
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.layer-item input[type="checkbox"] {
  cursor: pointer;
}

/* Sheets / Layouts Bar */
.layouts-bar {
  height: 40px;
  background: var(--bg-surface);
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  padding: 0 12px;
  gap: 6px;
  overflow-x: auto;
  z-index: 10;
  flex-shrink: 0;
}

.layout-tab {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: transparent;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 0.85rem;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.15s;
}

.layout-tab:hover {
  background: var(--bg-surface-hover);
  color: var(--text-primary);
}

.layout-tab.active {
  background: var(--accent-light);
  color: var(--accent);
  border-color: var(--accent);
  font-weight: 600;
}

/* Loading Modal */
.loading-modal {
  position: absolute;
  inset: 0;
  background: rgba(15, 23, 42, 0.75);
  backdrop-filter: blur(4px);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 30;
}

.loading-spinner {
  width: 44px;
  height: 44px;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin-bottom: 16px;
}

.loading-text {
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-primary);
}

.progress-bar-container {
  width: 240px;
  height: 6px;
  background: var(--border);
  border-radius: 3px;
  margin-top: 12px;
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  width: 0%;
  background: var(--accent);
  transition: width 0.15s ease;
}

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

.hidden {
  display: none !important;
}

/* Responsive adjustments */
@media (max-width: 640px) {
  .uploader-card {
    padding: 32px 20px;
  }
  .layers-panel {
    width: 100%;
  }
  .brand span {
    display: none;
  }
}