:root {
  --bg: #fafafa; --surface: #ffffff; --surface-2: #f2f2f2;
  --text: #141414; --text-muted: #555555; --border: #d4d4d4;
  /* The one accent — Google Sheets green. Interactive/actionable elements only; never a text colour. */
  --accent: #0f9d58; --on-accent: #0b0b0b; --focus: #0f9d58;
  /* Diff: added = accent tint + underline + solid edge; removed = neutral tint + strikethrough + dashed edge. */
  --ins-bg: #d9f2e4; --ins-em: #a6dcbd; --ins-edge: #0f9d58;
  --del-bg: #ececec; --del-em: #d2d2d2; --del-edge: #6b6b6b;
  --radius: 8px;
  --font: "Jost", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  /* User text (text boxes, comparison output): the system's fixed-width font — nothing to download. */
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  --text-title: 1.75rem; --text-heading: 1.25rem; --text-body: 1rem; --text-small: .875rem;
  --space-1: 8px; --space-2: 16px; --space-3: 24px; --space-4: 32px; --space-5: 48px;
  --control-height: 44px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #121212; --surface: #1a1a1a; --surface-2: #242424;
    --text: #ededed; --text-muted: #a3a3a3; --border: #383838;
    --accent: #0f9d58; --on-accent: #0b0b0b; --focus: #0f9d58;
    --ins-bg: #0e3522; --ins-em: #155c38; --ins-edge: #0f9d58;
    --del-bg: #2a2a2a; --del-em: #404040; --del-edge: #9a9a9a;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #121212; --surface: #1a1a1a; --surface-2: #242424;
  --text: #ededed; --text-muted: #a3a3a3; --border: #383838;
  --accent: #0f9d58; --on-accent: #0b0b0b; --focus: #0f9d58;
  --ins-bg: #0e3522; --ins-em: #155c38; --ins-edge: #0f9d58;
  --del-bg: #2a2a2a; --del-em: #404040; --del-edge: #9a9a9a;
  color-scheme: dark;
}