: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}}*{box-sizing:border-box}body{margin:0;font-family:Segoe UI,-apple-system,BlinkMacSystemFont,sans-serif;background:linear-gradient(135deg,#1e3c72,#2a5298);min-height:100vh;display:flex;align-items:center;justify-content:center;padding:20px}.calculator-container{width:100%;max-width:400px;margin:0 auto}.calculator{background:#1c1c1c;border-radius:28px;padding:24px;box-shadow:0 20px 40px #0006;overflow:hidden}.display-container{background:#000;border-radius:18px;padding:20px;margin-bottom:20px;text-align:right;min-height:120px;display:flex;flex-direction:column;justify-content:flex-end}.preview{color:#888;font-size:1.2rem;opacity:.8;margin-bottom:8px;min-height:28px}.display{color:#fff;font-size:3.5rem;font-weight:300;line-height:1;word-break:break-all;overflow-wrap:anywhere}.keypad{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}.btn{padding:20px;font-size:1.8rem;font-weight:500;border:none;border-radius:18px;cursor:pointer;transition:all .15s ease;-webkit-user-select:none;user-select:none;-webkit-tap-highlight-color:transparent}.btn:active{transform:scale(.95);opacity:.8}.number{background:#333;color:#fff}.number.zero{grid-column:span 2}.operator,.equals{background:#ff9500;color:#fff;font-weight:600}.equals{grid-row:span 2;display:flex;align-items:center;justify-content:center}.clear{background:#a6a6a6;color:#000}@media(max-width:480px){.display{font-size:3rem}.btn{padding:18px;font-size:1.6rem}.calculator{padding:20px;border-radius:24px}}@media(max-height:667px)and (orientation:landscape){.display{font-size:2.5rem}.btn{padding:14px;font-size:1.4rem}}