[FEATURE] Insights report should include a dark-mode theme

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

Problem

The /insights command generates a static HTML report at .claude/usage-data/report.html with a hardcoded light theme. There is no option to generate the report in dark mode.

Since the report is opened via file://, browser extensions like Dark Reader that auto-apply dark themes to web pages do not work on it.

For users who prefer dark mode (or are viewing the report in a dimly lit environment), the bright white backgrounds and light colour palette cause unnecessary eye strain.

Expected behaviour

The /insights command should support generating the report with a dark colour scheme - either via a flag (e.g. /insights --dark), a user preference in settings.json, or by respecting the system's appearance setting via a prefers-color-scheme media query in the generated CSS.

Proposed Solution

Workaround

dark-mode.sh

I've attached a shell script (dark-mode.sh) that post-processes the generated report.html, remapping the inline CSS colours to a dark palette.

Usage:

chmod +x dark-mode.sh
./dark-mode.sh ~/.claude/usage-data/report.html

Alternative Solutions

_No response_

Priority

Low - Nice to have

Feature Category

CLI commands and flags

Use Case Example

_No response_

Additional Context

_No response_