In a medium bowl, combine mayonnaise, sriracha hot sauce, white vinegar, granulated sugar, and lemon or lime juice. Whisk together until smooth and creamy.

Carefully shred imitation crab meat into thin strands using fingers or a fork.

Julienne cucumber and carrot into thin, matchstick-sized pieces.

Lay cucumber strips on paper towels and pat them dry gently to remove excess moisture.

In a large mixing bowl, combine shredded crab, dried cucumber strips, and julienned carrots. Pour in the creamy mayo dressing and toss gently.

Transfer to a serving bowl and sprinkle with panko crumbs. Chill in the refrigerator for at least 15 minutes before serving.