:root {
  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  --fs-xs: 12px;
  --fs-sm: 13px;
  --fs-base: 14px;
  --fs-md: 15px;
  --fs-lg: 16px;
  --fs-xl: 20px;
  --fs-stat: 24px;
  --lh: 1.45;

  /* Spacing */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-8: 32px;
  --gap: 14px;
  --card-pad: 14px;

  /* Sizing */
  --radius-sm: 6px;
  --radius: 8px;
  --radius-lg: 10px;
  --btn-h: 34px;
  --btn-h-sm: 30px;
  --input-h: 36px;
  --sidebar-w: 228px;
  --topbar-h: 52px;
  --content-max: 1080px;

  /* Colors */
  --color-bg: #f4f5f7;
  --color-surface: #ffffff;
  --color-surface-2: #f7f8fa;
  --color-border: #e3e6eb;
  --color-border-strong: #cfd4dc;
  --color-text: #1b2130;
  --color-text-2: #4b5565;
  --color-muted: #6b7484;
  --color-faint: #9aa3b2;

  --color-primary: #2451d6;
  --color-primary-hover: #1d43b3;
  --color-primary-soft: #eaf0ff;
  --color-primary-ring: rgba(36, 81, 214, 0.22);

  --color-success: #177a48;
  --color-success-bg: #e7f5ec;
  --color-success-border: #bfe3cc;

  --color-danger: #b42318;
  --color-danger-bg: #fdeceb;
  --color-danger-border: #f3c4c0;

  --color-warning: #9a5b00;
  --color-warning-bg: #fff6e5;
  --color-warning-border: #f4d9a6;

  --color-info: #185fa5;
  --color-info-bg: #e9f2fc;
  --color-info-border: #bdd7f2;

  /* Elevation */
  --shadow-sm: 0 1px 2px rgba(17, 24, 39, 0.06);
  --shadow: 0 2px 6px rgba(17, 24, 39, 0.08), 0 1px 2px rgba(17, 24, 39, 0.04);
  --shadow-lg: 0 10px 30px rgba(17, 24, 39, 0.16);

  /* Layers */
  --z-topbar: 30;
  --z-overlay: 39;
  --z-drawer: 40;
  --z-modal: 60;
  --z-toast: 70;

  /* Motion */
  --dur: 160ms;
  --ease: cubic-bezier(0.2, 0.7, 0.3, 1);
}