Here's a concept for a national stadium in Austria:
Design Inspiration:
 * The Alps: Austria's majestic mountains are a national symbol. The stadium's roof could evoke the silhouette of the Alps, with a wave-like design that rises towards the north.
 * Sustainability: Austria is a leader in green building practices. The stadium could incorporate solar panels on the roof, rainwater harvesting systems, and energy-efficient lighting.
 * Transparency: The facade could feature expansive windows offering panoramic views of the surrounding area, creating a connection between the stadium and the city.
Key Features:
 * Location: Ideally situated near a major city with excellent public transportation links.
 * Capacity: 80,000 spectators, with the ability to expand for mega-events.
 * Seating: Comfortable seating with excellent sightlines from every seat.
 * Retractable Roof: Allows for natural light and ventilation during good weather and provides shelter during rain or snow.
 * Fan Experience: Diverse concession stands, interactive areas, and a museum dedicated to Austrian football history.
Visualisation:
Imagine a majestic stadium nestled amidst a park, its sleek, wave-like roof clad in translucent materials that shimmer in the sunlight. Towering windows on the facade provide glimpses of the passionate crowd inside. Solar panels line the uppermost section of the roof, contributing to the stadium's sustainable operation.