body{font-family:Arial,sans-serif;text-align:center;display:flex;flex-direction:column;align-items:center;justify-content:flex-start;margin:0;padding:20px;min-height:100vh;background:#f0f0f0;color:#333}h1{margin:10px 0;font-size:2.5rem;color:#222}#button{font-size:10rem;cursor:pointer;background:none;border:none;outline:none;margin:20px 0;transition:transform .05s}#button:active{transform:scale(1.3)}@keyframes shake{0%,to{transform:translate(0)}25%{transform:translate(-5px)}75%{transform:translate(5px)}}@keyframes bounce{0%,to{transform:translateY(0)}50%{transform:translateY(-10px)}}.shake{animation:shake .3s ease-in-out}.bounce{animation:bounce .4s ease-out}.upgrade-hover-desc{font-size:.9em;color:#ccc;background:#222;padding:8px;border-radius:4px;margin-top:4px;transition:opacity .3s ease;opacity:0;pointer-events:none}.upgrade-item:hover .upgrade-hover-desc{opacity:1}