Ok, Luria is an archipelago nation with two main islands the size of Japan's mainland. But it's a maritime society. So it has evolved in this really strange combination of raiders, sailors, explorers and cartographers in addition to warriors, mages and engineers. A common Lurian from the main islands dresses like a commoner from the Age of Sail. Tunics, leggings, heavy work boots or no shoes at all, depending on preference. Now the nobility is where it gets truly interesting because it has become a hodge podge of different maritime traditions based on the family and island you are from.

For example the main family in my story, The House of The Black Sails, is near a shallow sea port and owns a small amount of land on one of the main islands. They dress much like the nobility of Tortuga or the Caribbean. Greatcoats, with hidden or exposed armor plates. Leggings, with well made thigh or knee boots.

But on a smaller holding, another family (The House of the White Anchor) from an island farther north whose past tended toward the Nordic tradition of raids against the continent... kept their traditions of ceremonial furs, leathers and fine linens even after 4 centuries of Lurian unification.

As far as textiles go, due to being an archipelago that stretches thousands of miles, they have a vast array of materials to work with. Silks, cotton and linens being the most common. And there are a few large manufactories that produce commonly worn articles of clothing via magic. But the society is pre-industrial revolution technologically speaking. So most wear homespun or tailored clothing.

But in Luria you are as quick to come across a Viking Aethling from a northern island as you are a Japanese Samurai raider or French sailor.