Lindsay Lohan was just remanded into custody -- following a STRONG warning from Judge Keith Schwartz -- "You're no different than anyone else ... please don't push your luck."
Moments after Lohan entered a not guilty plea in her felony theft case -- the judge came down on her like a ton of bricks ... telling her "things will be different" this time around because she's on the hook for a felony.
During the hearing, Judge Schwartz said Lindsay's lawyer, Shawn Chapman Holley, and prosecutor Danette Meyers, were going to meet to possibly reach a plea bargain.
Lohan -- alongside attorney Holley -- was then remanded into custody ... and is currently being booked.
Judge Schwartz set her bail at $20,000 -- but warned, "If you violate the law, I will remand you and there will be NO BAIL."
The judge also revoked Lindsay's probation in the DUI case and set bail at $20,000 -- so total bail is $40,000.
Lohan was also ordered to refrain from contacting the jewelry store during the case, after Meyers said someone had sent the store owners flowers, which kind of freaked them out.