server {
    listen 8080;
    server_name _;

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

    # Security headers
    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
    add_header Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data:; font-src 'self';" always;

    # Gzip compression
    gzip on;
    gzip_types text/plain text/css application/json application/javascript text/xml application/xml text/javascript;
    gzip_min_length 256;
    gzip_vary on;

    # Never cache index.html so the latest HTML is always served
    location = /index.html {
        add_header Cache-Control "no-cache, no-store, must-revalidate";
        add_header Pragma "no-cache";
        add_header Expires "0";
        try_files $uri =404;
    }

    # Cache hashed assets forever (filename contains content hash)
    location ~* \.(css|js|jpeg|jpg|png|gif|ico|svg|woff2?)$ {
        add_header Cache-Control "public, max-age=31536000, immutable";
        try_files $uri =404;
    }

    location / {
        try_files $uri $uri/ /index.html;
    }

    # Custom error pages
    error_page 404 /index.html;
}