:root{font-family:system-ui,Avenir,Helvetica,Arial,sans-serif;line-height:1.5;font-weight:400;color-scheme:light dark;color:#ffffffde;background-color:#242424;font-synthesis:none;text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}a{font-weight:500;color:#646cff;text-decoration:inherit}a:hover{color:#535bf2}body{margin:0;display:flex;place-items:center;min-width:320px;min-height:100vh}h1{font-size:3.2em;line-height:1.1}button{border-radius:8px;border:1px solid transparent;padding:.6em 1.2em;font-size:1em;font-weight:500;font-family:inherit;background-color:#1a1a1a;cursor:pointer;transition:border-color .25s}button:hover{border-color:#646cff}button:focus,button:focus-visible{outline:4px auto -webkit-focus-ring-color}@media (prefers-color-scheme: light){:root{color:#213547;background-color:#fff}a:hover{color:#747bff}button{background-color:#f9f9f9}}:root{--calculator-width: clamp(280px, 85vw, 400px);--button-padding: clamp(12px, 4vw, 25px);--button-font-size: clamp(1.1rem, 4vw, 1.8rem);--display-font-size: clamp(1.8rem, 6vw, 3rem);--display-padding: clamp(12px, 3vw, 25px);--gap-size: clamp(6px, 2vw, 12px);--container-padding: clamp(.5rem, 3vw, 2rem)}#root{max-width:100%;margin:0 auto;padding:var(--container-padding);text-align:center;box-sizing:border-box}.calculator-container{display:flex;flex-direction:column;align-items:center;gap:clamp(1rem,3vw,2rem);padding:var(--container-padding);width:100%;box-sizing:border-box}.calculator-container h1{font-size:clamp(1.5rem,5vw,2.5rem);margin-bottom:.5rem;color:#646cff}.keyboard-hint{font-size:clamp(.75rem,2.5vw,.9rem);color:#888;margin-bottom:.25rem;max-width:90%;line-height:1.5;padding:0 1rem}.operator-hint{font-size:clamp(.7rem,2.3vw,.85rem);color:#4caf50;margin-bottom:.5rem;max-width:90%;line-height:1.5;padding:0 1rem}.calculator{background:#1a1a1a;border-radius:clamp(12px,3vw,20px);padding:clamp(12px,3vw,20px);box-shadow:0 10px 30px #0000004d;width:var(--calculator-width);max-width:95vw;box-sizing:border-box}.display{background:#2d2d2d;color:#fff;font-size:var(--display-font-size);padding:var(--display-padding);text-align:right;border-radius:clamp(6px,2vw,10px);margin-bottom:clamp(10px,3vw,20px);min-height:clamp(40px,10vw,70px);word-wrap:break-word;overflow-wrap:break-word;overflow-x:auto}.buttons{display:grid;grid-template-columns:repeat(4,1fr);gap:var(--gap-size)}.btn{background:#3a3a3a;color:#fff;border:none;border-radius:clamp(6px,2vw,10px);font-size:var(--button-font-size);padding:var(--button-padding);cursor:pointer;transition:all .2s;font-weight:500;touch-action:manipulation;-webkit-tap-highlight-color:transparent}.btn:hover{background:#4a4a4a;transform:translateY(-2px)}.btn:active{transform:translateY(0);background:#4a4a4a}.btn-operation{background:#646cff;color:#fff}.btn-operation:hover,.btn-operation:active{background:#535bf2}.btn-clear{background:#f44;color:#fff}.btn-clear:hover,.btn-clear:active{background:#f66}.btn-equals{background:#4caf50;color:#fff}.btn-equals:hover,.btn-equals:active{background:#66bb6a}.expression-history{background:linear-gradient(135deg,#2d2d2d,#1a1a1a);padding:clamp(.75rem,2.5vw,1.25rem) clamp(1rem,3vw,2rem);border-radius:clamp(8px,2vw,12px);color:#fff;max-width:var(--calculator-width);width:100%;box-sizing:border-box;text-align:center;box-shadow:0 4px 15px #0003}.expression-label{font-size:clamp(.7rem,2vw,.85rem);color:#888;margin:0 0 .5rem;text-transform:uppercase;letter-spacing:1px}.expression-text{font-size:clamp(1rem,3.5vw,1.4rem);color:#646cff;margin:0;word-wrap:break-word;overflow-wrap:break-word;font-weight:500;line-height:1.5}@media (max-width: 480px){.keyboard-hint{display:none}}@media (min-width: 481px) and (max-width: 768px){:root{--calculator-width: clamp(320px, 60vw, 380px)}}@media (min-width: 769px){:root{--calculator-width: 380px;--button-padding: 22px;--button-font-size: 1.6rem;--display-font-size: 2.8rem}}@media (min-width: 1200px){:root{--calculator-width: 400px;--button-padding: 25px;--button-font-size: 1.8rem;--display-font-size: 3rem}}