Cleanup css and modules

src/components/close-button/close-button.css

src/components/meter/meter.css

src/components/meter/meter.jsx

src/components/modal/modal.css

src/components/prompt/prompt.css

src/components/record-modal/playback-step.jsx

src/components/record-modal/record-modal.css

src/components/record-modal/record-modal.jsx

src/components/record-modal/recording-step.jsx

src/components/waveform/waveform.css

src/components/waveform/waveform.jsx

src/css/colors.css