:root{font-family:system-ui,sans-serif;background:#0f172a;color:#e2e8f0}body{margin:0;display:grid;place-items:center;min-height:100dvh}.titulo{text-align:center;font-size:2rem;margin:20px 0 10px;color:#38bdf8}.container{width:min(420px,92vw);display:grid;gap:16px}.display-wrap{display:flex}.display{width:100%;font-size:2rem;padding:14px;border-radius:12px;border:none;background:#111827;color:#e5e7eb;text-align:right;box-shadow:inset 0 0 4px #000}.keys{display:grid;grid-template-columns:repeat(4,1fr);gap:10px}.keys button{padding:18px;font-size:1.25rem;border:none;border-radius:12px;background:#1f2937;color:#e5e7eb;cursor:pointer;transition:transform .1s ease,filter .2s ease}.keys button:hover{filter:brightness(1.2);transform:scale(1.05)}.equals{grid-row:span 2;background:#2563eb}.zero{grid-column:span 2}.history{background:#0b1220;border:1px solid #1f2937;border-radius:12px;padding:10px 14px;max-height:200px;overflow-y:auto}.history h2{margin-top:0;font-size:1.1rem;border-bottom:1px solid #1f2937;padding-bottom:4px}.history ul{list-style:none;padding:0;margin:0}.history li{font-family:ui-monospace,monospace;padding:6px 0;border-bottom:1px dashed #1f2937;cursor:pointer}.history li:hover{background:#1e293b}.clear-history{display:block;margin-bottom:8px;padding:6px 10px;font-size:.9rem;border:none;border-radius:8px;background:#dc2626;color:#fff;cursor:pointer}.clear-history:hover{filter:brightness(1.2)}