Celtics encouraged despite the loss to 76ers and Joel Embiids 52 points

PHILADELPHIA — Joe Mazzulla walked up and down the sidelines with fire in his eyes as the fourth quarter wound down Tuesday night. He called out angrily to one referee, then spun around to direct his argument at another. Boston was moments away from falling behind Philadelphia by seven points. The Celtics hadn’t yet staged a hectic comeback, which would feature several desperate tricks, including a perfectly missed free throw by Marcus Smart. They hadn’t yet lost 103-101 after Jayson Tatum’s long fadeaway bounced off the rim at the final buzzer. Mazzulla looked incensed. Like the rest of the Celtics…