body {
     background-image: url(https://png.pngtree.com/thumb_back/fh260/background/20220511/pngtree-vector-background-of-scientific-and-technological-system-for-calculating-complex-data-image_1298991.jpg);
     background-size: cover;
     background-position: center;
     background-repeat: no-repeat;
     display: flex;
     font-family: Arial, sans-serif;
     align-items: center;
     justify-content: center;
     height: 100vh;
     margin: 0px;
     padding: 0px;
     position: relative;

 }
 
 .calculator {
    position: relative;
    z-index: 1;
     padding: 30px;
     background-color: #269ed1cc;
     backdrop-filter: blur(10px);
     width: 300px;
     border-radius: 20px;
     box-shadow: 0 20 30px rgba(0, 0, 0, 0.5);
     border: 2px solid #fff;
     transition: transform 0.3s ease, box-shadow 0.3s ease;
 }

 h2 {
     text-align: center;
     color: #fff;
     margin-bottom: 20px;
     font-size: 26px;
     font-weight: bold;
     text-shadow: 2px 2px #000;
 }

 label {
     font-weight: bold;
     display: block;
     margin-bottom: 10px;
     color: #fff;
     text-shadow: 1px 1px #000;
 }

 input[type="number"] {
     padding: 12px;
     margin-bottom: 20px;
     font-size: 16px;
     font-weight: 600;
     width: 100%;
     border: 2px solid #ccc;
     border-radius: 10px;
 }

 #ans {
     color: #fff;
     text-align: center;
     font-size: 23px;
     font-weight: bold;
     margin-bottom: 20px;
     text-shadow: 1px 1px #000;

 }

 .btn {
     display: grid;
     grid-template-columns: repeat(2, 1fr);
     gap: 10px;
 }

 button {
     padding: 12px;
     font-size: 16px;
     font-weight: bold;
     cursor: pointer;
     border: none;
     border-radius: 10px;
     color: #fff;
     transition: transform 0.3s ease, background-color 0.3s ease;
     box-shadow: 0 5px 5px rgb(0 0 0 / 0.5);
 }

 #add {
     background-image: linear-gradient(45deg, #060e11, #434343);
 }

 #sub {
     background-image: linear-gradient(45deg, #d90404, #ff6666);
 }

 #mult {    
    background-image: linear-gradient(45deg, #04d904, #82ff82);
    color: #000;
 }

 #div {
    background-image: linear-gradient(45deg, #ffcb05, #fff39c);
    color: #000;

 }

 button:hover {
     transform: translateY(-3px);
     box-shadow: 0 10px 20px rgb(0 0 0 / 0.7);
     filter: brightness(1.1);
 }