:root {
  --bg-page: #f1f5f9;
  --bg-card: #ffffff;
  --bg-secondary: #f8fafc;
  --text-main: #0f172a;
  --text-muted: #64748b;
  --border-color: #e2e8f0;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --accent: #f59e0b;
  --table-head: #f1f5f9;
  --canvas-bg: #ffffff;
  --canvas-grid: #e2e8f0;
  --shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
}

/* 自动识别系统深色模式 */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg-page: #0b0f19;
    --bg-card: #131b2e;
    --bg-secondary: #080c16;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --border-color: #1e293b;
    --primary: #3b82f6;
    --primary-hover: #60a5fa;
    --table-head: #1e293b;
    --canvas-bg: #0f172a;
    --canvas-grid: #1e293b;
    --shadow: 0 4px 16px rgba(0, 0, 0, 0.45);
  }
}

/* 手动暗色模式 */
[data-theme="dark"] {
  --bg-page: #0b0f19;
  --bg-card: #131b2e;
  --bg-secondary: #080c16;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --border-color: #1e293b;
  --primary: #3b82f6;
  --primary-hover: #60a5fa;
  --table-head: #1e293b;
  --canvas-bg: #0f172a;
  --canvas-grid: #1e293b;
  --shadow: 0 4px 16px rgba(0, 0, 0, 0.45);
}

/* 手动亮色模式 */
[data-theme="light"] {
  --bg-page: #f1f5f9;
  --bg-card: #ffffff;
  --bg-secondary: #f8fafc;
  --text-main: #0f172a;
  --text-muted: #64748b;
  --border-color: #e2e8f0;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --table-head: #f1f5f9;
  --canvas-bg: #ffffff;
  --canvas-grid: #e2e8f0;
  --shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
}

body {
  margin: 0;
  padding: 0;
  background-color: var(--bg-page);
  color: var(--text-main);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  transition: background-color 0.25s ease, color 0.25s ease;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 8px 16px;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  background: var(--bg-card);
  color: var(--text-main);
  cursor: pointer;
  font-weight: 500;
  transition: all 0.2s;
}

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

.btn-primary {
  background: var(--primary);
  color: #ffffff !important;
  border: none;
}

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

.theme-toggle-btn {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  padding: 6px 12px;
  border-radius: 20px;
  cursor: pointer;
  color: var(--text-main);
  font-size: 13px;
  font-weight: 600;
}