End of Term Crossword 3/3: Everything, Everywhere

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Across
  1. 4. H.E.A.R.T perhaps (6)
  2. 5. Sliding cube very difficult to solve (6,4)
  3. 7. My back! (5)
  4. 8. This... is a crafting table! (9)
  5. 10. 1989 (6,5)
  6. 13. Flightless farm bird (7)
  7. 14. Blue (underlined?) text probably in a document (9)
  8. 16. Custard Cream's counterpart (7)
  9. 17. Betrayal, perhaps (6-5)
  10. 18. To put a wrapper in the bin? (7)
  11. 19. Always faster to switch to than reloading (9)
  12. 21. Similar to hamsters (6,4)
Down
  1. 1. Another word puzzle (10)
  2. 2. Sponge's snail (5)
  3. 3. Trains, taxis, buses, etc (6,14)
  4. 6. It nears! (6,7)
  5. 9. Eternally hungry (10)
  6. 11. Right of use? (7)
  7. 12. Difference between the 2 hints comprised of solely numbers (4)
  8. 15. 1984 (6,6)
  9. 20. Falling (during) Autumn (6)