Code block colors in Preview Mode ignore light/dark theme

[milen-yordanov]

See the attached screenshots from https://overtype.dev/demo
In Preview Mode, code block colors always appear as if a dark theme is active, even when the light theme is selected. This makes code blocks look incorrect and inconsistent with the rest of the preview.

I traced the issue to the following styles, which hardcode dark-theme colors for preview mode:
https://github.com/panphora/overtype/blob/main/src/styles.js#L764-L773

    /* Code blocks - proper pre/code styling in preview mode */
    .overtype-container[data-mode="preview"] .overtype-wrapper .overtype-preview pre.code-block {
      background: #2d2d2d !important;
      color: #f8f8f2 !important;
      padding: 1.2em !important;
      border-radius: 3px !important;
      overflow-x: auto !important;
      margin: 0 !important;
      display: block !important;
    }

Because these values are hardcoded, code blocks in Preview Mode do not adapt to the active light/dark theme.