Overlay colour thresholds miscalibrated for frWac vocabulary size

[FlorentPoinsaut]

Description

The overlay colour thresholds in index.html are:

if (p >= 0.9) return '#c9a227';  // gold
if (p >= 0.6) return '#2d7d46';  // green
return '#1a5c8a';                 // blue

With the current percentile formula and a vocabulary of ~150 000 words, these thresholds map to:

Colour	Threshold	Corresponds to
Gold	≥ 0.9	Top 15 000 words (top 10%)
Green	≥ 0.6	Top 60 000 words (top 40%)

A semantically irrelevant word like "légume" for target "maison" could appear gold. The visual hot/cold feedback that drives the game experience is broken.

Dependency

This issue is directly caused by #67 (percentile compression). The thresholds should be re-evaluated after the scoring formula is fixed. With a top-N rescaling (N=1000), the existing thresholds would become meaningful:

• Gold (≥ 90%) → top 100 words
• Green (≥ 60%) → top 600 words

If the scoring formula is fixed, this issue may resolve itself. If not, the thresholds must be recalibrated.

Files

• overlay/static/index.html — barColor() function