The Inheritance Games by Jennifer Lynn Barnes

Avery Grambs, a teenager with a challenging life, unexpectedly inherits a vast fortune from a mysterious billionaire, Tobias Hawthorne, whom she has never met. To claim her inheritance, Avery must move into the sprawling Hawthorne House, filled with secret passages and puzzles, and live alongside the disinherited Hawthorne family, who are determined to uncover why Tobias chose Avery over them. As Avery navigates the intricacies of the Hawthorne legacy, she becomes entangled in a thrilling game of riddles and secrets, uncovering hidden truths about the family and herself.