body{margin:0;padding:0;background:#000;color:#fff;font-family:Arial,sans-serif}.app-container{min-height:100vh;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:0}.centered{text-align:center}.title{font-size:3em;margin-bottom:20px;color:#0f0}.subtitle{font-size:1.2em;margin-bottom:30px;line-height:1.6}.red-text{color:red}.green-text{color:#0f0}.primary-button{padding:15px 40px;font-size:1.5em;background:#0f0;color:#000;border:none;border-radius:8px;cursor:pointer;font-weight:700;margin-bottom:40px;transition:transform .1s ease}.primary-button:hover{transform:scale(1.05)}.primary-button:disabled{opacity:.5;cursor:not-allowed}.full-width{width:100%}.stats-bar{margin-bottom:30px;display:flex;gap:40px;justify-content:center;font-size:1.2em}.card{background:#111;padding:20px;border-radius:8px;border:2px solid #0f0}.card-large{padding:30px}.score-row{display:flex;justify-content:space-between;padding:10px}.score-row:not(:last-child){border-bottom:1px solid #333}.game-over-title{font-size:3em;margin-bottom:30px;color:#0f0}input{padding:12px;font-size:1.2em;width:100%;margin-bottom:15px;background:#222;color:#fff;border:2px solid #0f0;border-radius:8px;outline:none;box-sizing:border-box}input:focus{box-shadow:0 0 8px #0f0}.new-score{animation:highlightScore 1s ease-in-out alternate;background:#00ff001a}@keyframes highlightScore{0%{transform:scale(1);box-shadow:0 0 #0f0}to{transform:scale(1.05);box-shadow:0 0 15px #0f0}}.reset-button{margin-top:12px;padding:6px 12px;border-radius:6px;border:1px solid #666;background:transparent;color:#ccc;cursor:pointer}.reset-button:hover{color:#fff;border-color:#fff}.top-bar{padding:20px}.back-button{text-decoration:none;color:#0f0;border:1px solid #0f0;padding:6px 12px;border-radius:8px;font-weight:600;transition:all .2s ease}.back-button:hover{background:#0f0;color:#000}.equation-box{background:#111;border:2px solid #0f0;border-radius:8px;padding:40px;font-size:3em;font-weight:700;text-align:center;min-height:120px;display:flex;align-items:center;justify-content:center;margin-bottom:20px}.answer-display{background:#222;border:2px solid #0f0;border-radius:8px;padding:20px;font-size:2.5em;font-weight:700;text-align:right;color:#0f0;min-height:80px;display:flex;align-items:center;justify-content:flex-end;font-family:Courier New,monospace;letter-spacing:2px;margin-bottom:10px}.keypad{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;width:100%;margin-bottom:10px}.keypad-button{background:#333;border:2px solid #555;color:#fff;font-size:2em;font-weight:700;padding:25px;border-radius:8px;cursor:pointer;transition:background .1s}.keypad-button:hover{background:#444;border-color:#0f0}.keypad-button:active{background:#0f0;color:#000}@media (max-width: 600px){.title{font-size:2em}.subtitle{font-size:1em}.equation-box{font-size:2em;padding:30px;min-height:100px}.answer-display{font-size:1.8em;padding:15px;min-height:60px}.keypad-button{font-size:1.5em;padding:20px}.stats-bar{font-size:.9em;flex-direction:column;gap:10px;text-align:center}}