* { margin: 0; padding: 0; box-sizing: border-box; }
        html, body {
            height: 100%;
            overflow: hidden;
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
            background: #f5f5f5;
        }
        body { display: flex; flex-direction: column; }