* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: 'Arial', sans-serif; background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%); display: flex; justify-content: center; align-items: center; height: 100vh; }
.calculator { background: white; padding: 30px; border-radius: 15px; box-shadow: 0 10px 20px rgba(0,0,0,0.1); width: 300px; text-align: center; }
h2 { margin-bottom: 20px; color: #333; }
.input-group { margin-bottom: 15px; text-align: left; }
label { display: block; margin-bottom: 5px; color: #666; font-size: 14px; }
input { width: 100%; padding: 10px; border: 1px solid #ddd; border-radius: 5px; outline: none; }
input:focus { border-color: #007bff; }
button { width: 100%; padding: 12px; background: #007bff; color: white; border: none; border-radius: 5px; cursor: pointer; font-size: 16px; margin-top: 10px; transition: 0.3s; }
button:hover { background: #0056b3; }
.result { margin-top: 20px; font-weight: bold; font-size: 18px; padding: 10px; border-radius: 5px; }