<style> body{ font-family:Arial,sans-serif; background:#f4f4f4; display:flex; justify-content:center; align-items:center; height:100vh; margin:0; } .calculator{ background:#fff; padding:25px; border-radius:12px; box-shadow:0 4px 15px rgba(0,0,0,.2); width:320px; } h2{ text-align:center; margin-bottom:20px; } input,select{ width:100%; padding:12px; margin:8px 0; font-size:16px; border:1px solid #ccc; border-radius:6px; } .buttons{ display:grid; grid-template-columns:1fr 1fr; gap:10px; margin-top:15px; } button{ padding:12px; border:none; border-radius:6px; background:#0066ff; color:#fff; font-size:16px; cursor:pointer; } button:hover{ background:#004dcc; } #result{ margin-top:20px; padding:15px; background:#f0f0f0; border-radius:6px; text-align:center; font-size:20px; font-weight:bold; } </style>