body {
	background: linear-gradient(-45deg, #ee7752, #e73c7e, #23a6d5, #23d5ab,yellow);
	background-size: 400% 400%;
	animation: gradient 15s ease infinite;
	height: 100vh;
}

@keyframes gradient {
	0% {
		background-position: 0% 50%;
	}
	50% {
		background-position: 100% 50%;
	}
	100% {
		background-position: 0% 50%;
	}
}

#container{
    margin:0 auto;
    position: absolute;
    top:30%;
    left:30%;
    width:480px;
   
  }
  
  #numb-container{
  
    width:480px;
    margin:0 auto;
    display:flex;
    flex-direction: column;
    justify-content: space-between;
    cursor: pointer;
    /* background:#333; */
    
    
  }

  #inner-container{
      display:flex;   
  }
  button{
      width:100%;
      background:rgba(190, 190, 190, 0.555);
      padding: 1rem;
      border:1px solid grey;
      color:#333;
      font-family: 'Trebuchet MS', 'Lucida Sans Unicode', 'Lucida Grande', 'Lucida Sans', Arial, sans-serif;
      font-size: 1rem;
      cursor: pointer;

  }
  button:active{
   
        background-color: rgba(255, 255, 255, 0.726);
        color: #333;
        transition: .5sec ease-in;

  }
  #input-container{
   width:480px;
    display:flex;
    flex-direction:column;
    justify-content: flex-end;
    align-items:flex-end;
    margin:0 auto; 
    border:2px solid;
    background:rgba(190, 190, 190, 0.555);
    color:rgba(0, 0, 0, 0.699);
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    border-radius:5px;
    border: none;
    
  }
  .previou{
    font-size:1.25rem;
    margin-right:.5rem
  }
  .current{
    margin-right:.5rem;
  }
  
  .btn{
    padding:.8rem;
    border-radius:0px 
  }
  #operand{
    display:flex;
    flex-direction:column
  }
  .btn-danger{
    width:3rem
  }

  @media only screen and (max-width:700px){
      body{
          height:100vh;
          background-size: 300% 300%;
          
      }
      #container{
          width:300px;
          top:20%;
          left:40px
      }
      button{
          padding: .7rem;
      }
    #input-container{
        width:300px;
       

    }
    #numb-container{
        width: 300px;
    }

  }