:root {
  color-scheme: light;
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --background: #f6f7fb;
  --surface: #ffffff;
  --surface-raised: #ffffff;
  --surface-soft: #f0f2f7;
  --surface-strong: #e7eaf1;
  --foreground: #151821;
  --text-secondary: #666c7a;
  --text-tertiary: #8b91a0;
  --border: #e2e5ec;
  --border-strong: #d5d9e3;
  --primary: #181a22;
  --primary-hover: #2b2e39;
  --focus: #2563eb;
  --user: #137c60;
  --user-soft: #e8f6f1;
  --user-border: #b9e4d5;
  --data: #a64b00;
  --data-soft: #fff3e8;
  --data-border: #efc18f;
  --ai: #7133c6;
  --ai-soft: #f2ebfc;
  --ai-border: #dac4f4;
  --warning: #a66113;
  --warning-soft: #fff5e5;
  --shadow-sm: 0 1px 2px rgba(20, 24, 33, 0.04);
  --shadow-md: 0 12px 32px rgba(24, 26, 34, 0.07);
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 22px;
  --motion-fast: 160ms;
  --motion-base: 240ms;
}

[data-theme="dark"] {
  color-scheme: dark;
  --background: #111319;
  --surface: #181b23;
  --surface-raised: #1d2029;
  --surface-soft: #222630;
  --surface-strong: #2a2f3a;
  --foreground: #f4f5f7;
  --text-secondary: #b2b7c3;
  --text-tertiary: #858c9b;
  --border: #2b303b;
  --border-strong: #3a404c;
  --primary: #f4f5f7;
  --primary-hover: #ffffff;
  --focus: #7da6ff;
  --user: #55c7a5;
  --user-soft: #17372f;
  --user-border: #245d4d;
  --data: #ffb45c;
  --data-soft: #3b2818;
  --data-border: #70471f;
  --ai: #b993f1;
  --ai-soft: #302347;
  --ai-border: #523a77;
  --warning: #f2b65e;
  --warning-soft: #3d2d18;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.18);
  --shadow-md: 0 18px 42px rgba(0, 0, 0, 0.24);
}