A Gentle 7×7 Puzzle Solved with Shape Squeeze in 12 Steps

This 7×7 board rates as gentle (difficulty score 778). Solving it from scratch takes 12 logical steps, using 6 techniques: Single cell, Row/column exclusion, Adjacency clear, Region confinement, Line confinement, Shape squeeze. Every step below is forced: nothing here is a guess.

1. First, every open cell left in this region sits in row 1, so its marker has to land there; that clears every other open cell in the row.
2. Next, every open cell in column G belongs to the same region, so that region's marker has to be somewhere in this column; that clears every other open cell in the region.
3. Then, every open cell in column F belongs to the same region, so that region's marker has to be somewhere in this column; that clears every other open cell in the region.
4. After that, every open cell in column E belongs to the same region, so that region's marker has to be somewhere in this column; that clears every other open cell in the region.
5. Now, place a marker at D2. Column 4 has exactly one open cell left. Placing here clears the rest of row 2, column D, and its region. Placing here also clears its 2 touching neighbours.
6. From there, place a marker at B1. Region has exactly one open cell left. Placing here clears the rest of row 1, column B, and its region.
7. Following that, place a marker at E4. Region has exactly one open cell left. Placing here clears the rest of row 4, column E, and its region.
8. First, place a marker at A3. Region has exactly one open cell left. Placing here clears the rest of row 3, column A, and its region.
9. Next, every remaining candidate in this region touches F6, so whichever candidate ends up marked will clear it, and it can be ruled out now regardless of which one wins.
10. Then, place a marker at F7. Region has exactly one open cell left. Placing here clears the rest of row 7, column F, and its region. Placing here also clears its 1 touching neighbour.
11. After that, place a marker at G5. Region has exactly one open cell left. Placing here clears the rest of row 5, column G, and its region.
12. Finally, place a marker at C6. Region has exactly one open cell left.

The key move here was Shape squeeze. Once you can spot that, this board falls quickly. ∎