server {
    listen 80;
    server_name _;

    root /usr/share/nginx/html;
    index index.html;

    # Security headers
    add_header X-Content-Type-Options "nosniff" always;
    add_header X-Frame-Options "DENY" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;

    # Enable compression
    gzip on;
    gzip_types text/css application/javascript text/javascript application/wasm image/svg+xml;
    gzip_min_length 512;

    # Immutable cache for hashed assets
    location /assets/ {
        expires 1y;
        add_header Cache-Control "public, immutable";
    }

    # Everything else → index.html (SPA fallback)
    location / {
        try_files $uri $uri/ /index.html;
        expires -1;
        add_header Cache-Control "no-cache";
    }
}