This is a complete, single-file "SaaS-ready" application. It includes the calculation logic, responsive design, and premium UI elements as specified. ```html Free Podcast Sponsor CPM & Ad Rate Calculator Tool

Podcast Sponsor Calculator

Estimate your potential ad revenue with industry-standard metrics.

Calculation Inputs

Avg. Downloads per Episode

Average CPM ($)

Pre-Roll

Mid-Roll

Post-Roll

Revenue Forecast

Per Episode

$0.00

Monthly (4 eps)

$0.00

Annually

$0.00