Accessibility

For accessibility the following needs to be improved:

1. Header "PTB Untertitel Dienst" must be H1 (not H2)

2. Footer must have more contrast (at least 7:1), so please use darker font (darker grey or black)

3. The "checkmarks" are not read by a screenreader. Please add a "visually hidden"-Tag and repeat here what's in there "An diese Adresse wird die Untertiteldatei verschickt" und "Die gesprochene Sprache der Aufnahme..." (please contact Christopher Schulz for how this can be done)

   or add it to the input field label (e.g. instead of "Email" "Email-Adresse, an die die Untertiteldatei verschickt werden soll")