:root{--slate-dark: #0f172a;--board-bg: #1e293b;--slate-border: #334155;--chalk-text: #f8fafc;--accent-cyan: #22d3ee;--danger-red: #ef4444;--font-hand: "Comic Neue", sans-serif, cursive;--font-tech: "Comic Neue", sans-serif, cursive}body{margin:0;background-color:var(--slate-dark);display:flex;justify-content:center;align-items:center;height:100vh;font-family:Comic Neue,sans-serif,cursive;color:var(--chalk-text)}#chalkboard{width:90vw;max-width:900px;background-color:var(--board-bg);border:2px solid var(--slate-border);border-radius:12px;position:relative;padding:30px;box-shadow:0 20px 50px #00000080;flex-direction:column;min-height:400px;height:auto;display:block;overflow:visible}#chalkboard:before{content:"";position:absolute;top:0;right:0;bottom:0;left:0;background-image:linear-gradient(var(--slate-border) 1px,transparent 1px),linear-gradient(90deg,var(--slate-border) 1px,transparent 1px);background-size:40px 40px;opacity:.1;pointer-events:none}header{display:flex;justify-content:space-between;align-items:center;border-bottom:1px solid var(--slate-border);padding-bottom:15px}h1{font-size:1.2rem;margin:0;letter-spacing:3px;color:var(--accent-cyan)}.version{font-size:.7rem;opacity:.5;vertical-align:super}#status-dot{width:8px;height:8px;background:orange;border-radius:50%;display:inline-block;margin-right:5px}#student-work{flex-grow:1;display:flex;justify-content:center;align-items:center;font-weight:700;font-family:var(--font-hand);color:var(--accent-cyan);text-shadow:2px 2px 5px rgba(0,0,0,.3);background:linear-gradient(#ffffff1a,#ffffff1a);-webkit-background-clip:text;background-clip:text;opacity:.9;white-space:pre-wrap;line-height:1.6;margin-top:20px;font-size:1.2rem}.input-wrapper{display:flex;align-items:center;gap:15px;padding-top:15px}#answer-input{background:transparent;border:none;color:var(--accent-cyan);outline:none;width:100%;font-family:var(--font-hand);font-size:1.8rem}#clear-btn{background:transparent;border:1px solid var(--danger-red);color:var(--danger-red);padding:5px 10px;cursor:pointer;font-size:.7rem;border-radius:4px}#clear-btn:hover{background:var(--danger-red);color:#fff}@keyframes successPulse{0%{border-color:var(--slate-border);box-shadow:0 0 #22d3ee00}50%{border-color:var(--accent-cyan);box-shadow:0 0 40px #22d3ee99}to{border-color:var(--slate-border);box-shadow:0 0 #22d3ee00}}.success-glow{animation:successPulse 1.5s ease-out}#streak-counter{font-weight:700;color:var(--accent-cyan);border:1px solid var(--accent-cyan);padding:4px 12px;border-radius:20px;font-size:.8rem;background:#22d3ee1a}#math-problem{font-family:var(--font-hand);font-size:2.2rem;color:var(--chalk-text);letter-spacing:1px}.primary-btn{background:var(--accent-cyan);color:var(--slate-dark);border:none;padding:8px 20px;font-weight:700;border-radius:4px;cursor:pointer;letter-spacing:1px}.primary-btn:hover{background:#fff;box-shadow:0 0 15px var(--accent-cyan)}.category-menu{display:flex;gap:10px;justify-content:center;margin-top:20px}.cat-btn{background:transparent;border:1px solid var(--slate-border);color:var(--chalk-text);padding:8px 15px;font-size:.7rem;border-radius:4px;cursor:pointer;transition:.3s}.cat-btn:hover{border-color:var(--accent-cyan);color:var(--accent-cyan);background:#22d3ee1a}.shake{animation:shake .5s cubic-bezier(.36,.07,.19,.97) both}@keyframes shake{10%,90%{transform:translate3d(-1px,0,0)}20%,80%{transform:translate3d(2px,0,0)}30%,50%,70%{transform:translate3d(-4px,0,0)}40%,60%{transform:translate3d(4px,0,0)}}