:root{--color-bg: #f0f4f8;--color-board-light: #eeeed2;--color-board-dark: #769656;--color-highlight: rgba(255, 255, 0, .5);--color-primary: #4a90e2;--color-secondary: #e2904a;--color-text: #2c3e50;--font-main: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif}body{margin:0;font-family:var(--font-main);background-color:var(--color-bg);color:var(--color-text);overscroll-behavior:none}#root{display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:100vh;width:100%}.game-container{display:flex;flex-direction:column;align-items:center;gap:1rem;width:100%;max-width:600px;padding:1rem;box-sizing:border-box}.board-container{width:100%;aspect-ratio:1 / 1;display:grid;grid-template-columns:repeat(8,1fr);grid-template-rows:repeat(8,1fr);border:5px solid #5d4037;border-radius:4px;box-shadow:0 4px 10px #0003;background-color:var(--color-board-light)}.square{width:100%;height:100%;display:flex;align-items:center;justify-content:center;position:relative}.square.light{background-color:var(--color-board-light)}.square.dark{background-color:var(--color-board-dark)}.square.highlight{background-color:var(--color-highlight)!important}.square.check{background-color:#f006!important}.square.valid-move:after{content:"";width:20%;height:20%;background-color:#0003;border-radius:50%}.square.threatened{animation:pulse-threat 1.5s ease-in-out infinite}@keyframes pulse-threat{0%,to{box-shadow:inset 0 0 #f006}50%{box-shadow:inset 0 0 20px #ff0000b3}}.piece{width:90%;height:90%;cursor:grab;touch-action:none;background-size:contain;background-repeat:no-repeat;background-position:center}.piece:active{cursor:grabbing}.controls{display:flex;gap:1rem;flex-wrap:wrap;justify-content:center;width:100%}.btn{background-color:var(--color-primary);color:#fff;border:none;padding:12px 24px;font-size:1.2rem;border-radius:12px;cursor:pointer;font-family:inherit;box-shadow:0 4px #357abd;transition:transform .1s,box-shadow .1s;font-weight:700}.btn:active{transform:translateY(4px);box-shadow:0 0 #357abd}.btn-large{width:100%;padding:20px;font-size:1.5rem;margin-bottom:1rem}.teacher-area{background-color:#fff;padding:1rem;border-radius:16px;box-shadow:0 4px 12px #0000001a;display:flex;align-items:center;gap:1rem;width:100%;box-sizing:border-box;border:2px solid #e0e0e0}.teacher-avatar{width:60px;height:60px;background-color:#e3f2fd;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:2.5rem;border:2px solid var(--color-primary)}.teacher-text{font-size:1.1rem;font-weight:600;color:var(--color-text)}.main-menu{display:flex;flex-direction:column;align-items:center;justify-content:center;width:100%;max-width:400px;gap:2rem;text-align:center}.main-menu h1{font-size:3rem;color:var(--color-primary);text-shadow:2px 2px 0 #fff,4px 4px 0 rgba(0,0,0,.1);margin-bottom:1rem}.menu-buttons{width:100%;display:flex;flex-direction:column;gap:1rem}.blunder-overlay{position:fixed;top:0;left:0;width:100%;height:100%;background-color:#000000b3;display:flex;align-items:center;justify-content:center;z-index:1000;animation:fadeIn .3s ease-in-out}@keyframes fadeIn{0%{opacity:0}to{opacity:1}}.blunder-dialog{background:linear-gradient(135deg,#667eea,#764ba2);padding:2rem;border-radius:20px;box-shadow:0 10px 40px #0000004d;max-width:400px;width:90%;text-align:center;animation:slideIn .3s ease-out;color:#fff}@keyframes slideIn{0%{transform:translateY(-50px);opacity:0}to{transform:translateY(0);opacity:1}}.blunder-owl{font-size:4rem;margin-bottom:1rem;animation:bounce .6s ease-in-out}@keyframes bounce{0%,to{transform:translateY(0)}50%{transform:translateY(-15px)}}.blunder-dialog h2{font-size:2rem;margin:0 0 1rem;color:#fff}.blunder-message{font-size:1.2rem;margin-bottom:2rem;line-height:1.5;color:#f0f0f0}.blunder-buttons{display:flex;gap:1rem;justify-content:center;flex-wrap:wrap}.blunder-buttons .btn{flex:1;min-width:140px}.btn-primary{background-color:#4caf50;box-shadow:0 4px #388e3c}.btn-primary:active{box-shadow:0 0 #388e3c}.btn-secondary{background-color:#ff9800;box-shadow:0 4px #f57c00}.btn-secondary:active{box-shadow:0 0 #f57c00}