Lenox, Mass. ? A century after author and designer Edith Wharton built her showplace home in the Berkshires, the 35-room hillside mansion called The Mount offers an updated glimpse of the elegance of the Gilded Age.

As part of a centennial celebration, the Edith Wharton Restoration invited seven interior designers to furnish the mansion’s newly restored main rooms, based on Wharton’s 1897 book, “The Decoration of Houses,” in which she promoted classical simplicity.

Rebecca Bell, a press representative for The Mount, walks down stairs inside the main house at author Edith Wharton's former estate in Lenox, Mass. The Mount's main house and gardens, restored in the past few years to their former elegance, will reopen to the public Wednesday.

“We wanted to demonstrate how Wharton’s design theories are timeless … how these rooms might have looked if she were alive today,” said Stephanie Copeland, president and chief executive officer of the restoration.

And so, a soft modern upholstered sofa and delicate rolled shades mix with the formality of French Provincial chairs in the den that served as the retreat of Wharton’s husband. One wall is decorated with a saucy modern collage of gossipy grande dames whispering acerbic comments on marriage.

“It reflects both Mrs. Wharton’s sense of order and Mr. Wharton’s desire for comfort,” said designer Thomas Jayne. Wharton’s husband, Teddy, always had an eye for the ladies, Jayne added, noting that both Whartons were having extramarital affairs when their home was built.

The mansion’s main rooms and graceful gardens, which reopen Wednesday, comprise the bulk of the first $14 million phase of the restoration, Copeland said. Eventually, the group hopes to track down and acquire more of the original furnishings. The entire project will cost $35 million.

“Actually, we are a little ahead of her,” Copeland said, noting that Wharton, although born to wealth, needed the proceeds from her best-selling novel, “The House of Mirth,” to complete the mansion and its gardens in 1905.

The simplicity of the high-ceilinged rooms is lightened by delicate decorative plaster work and wide French doors opening out into a sweeping terrace where the Whartons entertained literary luminaries.

“She’s pictured sitting at a desk here, but she never did any of her writing here,” Copeland said in the library with its ornately carved wood paneling.

“She always wrote in bed at a lap desk with the dog of the moment at her side. As she finished each page in longhand, she would drop it on the floor. Later, a maid would pick up the pages and bring them to her for proofing and editing.”

The focal point of the house remains the view from the terrace of Laurel Pond and the mountains across the receding squares of the formal gardens, which Wharton called “outdoor rooms.”

She was proudest of the gardens where she said “each step away from architecture was a nearer approach to nature.”

Wharton, who was the first woman to win the Pulitzer Prize for her novel “The Age of Innocence,” left The Mount for France in 1911 and spent the rest of her life there, returning to the United States only to accept the Pulitzer Prize in 1920. She died in 1937 at the age of 75.

Her husband sold the home when she left and they divorced a year later. From 1942 until 1972, the mansion was a girl’s school. It had fallen into disrepair by the time it caught the eye of Tina Packer, artistic director of Shakespeare & Co., which established a separate board of directors to oversee and acquire the National Historic Landmark in 1980.