.container{text-align:center;box-sizing:border-box;flex-direction:column;justify-content:center;align-items:center;max-width:600px;min-height:100vh;margin:0 auto;padding:20px;font-family:Arial,sans-serif;display:flex}h1{margin-bottom:10px;font-size:2rem}.card{background-color:#f1f1f1;border-radius:12px;justify-content:center;align-items:center;width:120px;height:120px;margin:20px auto;padding:30px;font-size:48px;font-weight:700;transition:transform .5s,color .5s;display:flex}.card.flip{transform:rotateY(180deg)}@keyframes shake{0%{transform:translate(0)}20%{transform:translate(-8px)}40%{transform:translate(8px)}60%{transform:translate(-6px)}80%{transform:translate(6px)}to{transform:translate(0)}}.card.shake{animation:.4s shake}.guess-controls{flex-wrap:wrap;justify-content:center;gap:10px;margin:20px 0;display:flex}.guess-controls button,.submit-btn{cursor:pointer;color:#fff;border:none;border-radius:8px;padding:12px 20px;font-size:16px;transition:background-color .3s,transform .2s}.guess-controls button{background-color:#0070f3}.guess-controls button:hover{background-color:#005dc1;transform:scale(1.05)}.guess-controls button:active{transform:scale(.95)}.submit-btn{background-color:#28a745;margin-top:10px}.submit-btn:hover{background-color:#1f8c3b;transform:scale(1.05)}.submit-btn:active{transform:scale(.95)}.message{margin:10px 0;font-size:22px;font-weight:500}.secret-code{color:#4cff43;margin-top:15px;font-size:18px;font-weight:700}@keyframes flashRed{0%{color:red;transform:scale(1)}50%{color:#f66;transform:scale(1.2)}to{color:red;transform:scale(1)}}@keyframes flashBlue{0%{color:#00f;transform:scale(1)}50%{color:#6af;transform:scale(1.2)}to{color:#00f;transform:scale(1)}}.message.flash-red{animation:.5s ease-in-out flashRed}.message.flash-blue{animation:.5s ease-in-out flashBlue}@media (max-width:768px){.card{width:100px;height:100px;padding:20px;font-size:36px}h1{font-size:1.5rem}.guess-controls button,.submit-btn{padding:10px 16px;font-size:14px}.message{font-size:18px}}