I've been reporting on celebrity-approved laptop bag s since I joined the Marie Claire team last May. I didn't find an MC -worthy work bag until I saw Rose Byrne's Longchamp tote for a March 6 press appearance. Yes, she sourced Longchamp, but not for the Le Pliage beloved by chic women from here to Paris Fashion Week . The Actor Award nominee traded the foldable, $180 carry-all for its four-figure, older sister: the Longchamp Le Smart Handbag . Instead of recycled canvas, the French brand crafted the belted, top-handle tote's 13.4-inch-long body from brown "Mocha" calfskin leather. And with that, Longchamp brought my luxury laptop bag dreams to life. Rose Byrne put the Longchamp Le Smart laptop bag on my radar—now I'm hooked. (Image credit: Getty Images) Don't get me wrong, I'm still a Longchamp Le Pliage lifer. The durable, origami-designed tote singlehandedly got me through college—and for that I'll always be grateful. But sometimes, I wish the elongated zipper and top-flap were a bit more accessible.…