Cryptic crossword No 3,645

Across

1. Mastermind fully keeps alert (7)
2. Calculated buffet at deli stocking leftovers at opening (7)
3. Retiring swimmer pursues golf for pleasure (4)
4. Pawn I blunder let opponent's endgame in- it may be too late? (3,6)
5. Handle tea & cake for Brahms and Liszt (4,4,2)
6. Aboard a ship, left dock (4)
7. Paid back- for example- returning diamonds after he leaves paradise (7)
8. Head to where the Spanish show up, it's nice when warm ? (7)
9. Liquor old writer almost put in tea (7)
10. Perhaps cut-throat one who lifts escaping from trap (5)
11. Covering for Pope Leo in mix-up, eating variety of fruit skin (6,4)
12. As a bonus, briefly managed to follow previous time (5)
13. In the office, catching glimpse of Renaissance painting, maybe (7)
14. I toast to the primarily drunk person, making lasting impressions? (9)

Down

1. Delicate petal blowing softly around this place (8)
2. A badger relaxed (2,4)
3. Female deer picked up bucks (5)
4. Something unpredictable did crawl around (8) (8)
5. Limits sleep and showers (9)
6. Pet butterfly? (6)
7. Seafood to start- £1 calamari (5)
8. Wealth’s regularly polled? No thank you (6)
9. Heartlessly knock down one street with small, blossoming businesses (8)
10. Man with many hats, caps from Adidas, and denim jackets, all for dancing (4-2-3-6)
11. Skilled artists organise clothing line on the counter  (8)
12. Phoenix’s state (Arizona) entered into database section, missing initial letter (6)
13. Basic dart arrow's flight scoring 50, amazingly (15)
14. Snake’s finally back in Great Britain, swallowing most of cow and tailless rat (4,5)  (4,5)