*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}


body {
    margin: auto;
    font-family: -apple-system, BlinkMacSystemFont, sans-serif;
    overflow: auto;
    background: linear-gradient(315deg, rgba(101,0,94,1) 3%, rgba(60,132,206,1) 38%, rgba(48,238,226,1) 68%, rgba(255,25,25,1) 98%);
    animation: gradient 15s ease infinite;
    background-size: 400% 400%;
    background-attachment: fixed;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100hv;
}

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

.wave {
    background: rgb(255 255 255 / 25%);
    border-radius: 1000% 1000% 0 0;
    position: fixed;
    width: 200%;
    height: 12em;
    animation: wave 10s -3s linear infinite;
    transform: translate3d(0, 0, 0);
    opacity: 0.8;
    bottom: 0;
    left: 0;
    z-index: -1;
}

.wave:nth-of-type(2) {
    bottom: -1.25em;
    animation: wave 18s linear reverse infinite;
    opacity: 0.8;
}

.wave:nth-of-type(3) {
    bottom: -2.5em;
    animation: wave 20s -1s reverse infinite;
    opacity: 0.9;
}

@keyframes wave {
    2% {
        transform: translateX(1);
    }

    25% {
        transform: translateX(-25%);
    }

    50% {
        transform: translateX(-50%);
    }

    75% {
        transform: translateX(-25%);
    }

    100% {
        transform: translateX(1);
    }
}

.calculator{
    background:rgb(53, 87, 101);
    border-radius: 20px;
    padding: 20px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.3);
    width: 320px;
}

.display{
    background:transparents;
    color: #fff;
    font-size: 2.5rem;
    font: bold;
    padding: 20px;
    text-align: right;
    border-radius: 10px;
    margin-bottom: 20px;
    min-height: 80px;
    word-wrap: break-word;
    word-break: break-all;
    overflow-x: auto;

}

.buttons{
    display: grid;
    grid-template-columns: repeat(4,1fr);
    gap: 10px;

}

.button{
    padding: 10px 20px;
  text-transform: uppercase;
  border-radius: 8px;
  font-size: 17px;
  font-weight: 500;
  color: #ffffff80;
  text-shadow: none;
  background: transparent;
  cursor: pointer;
  box-shadow: transparent;
  border: 1px solid #ffffff80;
  transition: 0.5s ease;
  user-select: none;
}

#btn:hover,
:focus {
  color: #ffffff;
  background: #008cff;
  border: 1px solid #008cff;
  text-shadow: 0 0 5px #ffffff, 0 0 10px #ffffff, 0 0 20px #ffffff;
  box-shadow: 0 0 5px #008cff, 0 0 20px #008cff, 0 0 50px #008cff,
    0 0 100px #008cff;
}

  button:hover {
            transform: scale(1.05);
        }

        button:active {
            transform: scale(0.95);
        }

        .btn-number,
        .btn-decimal {
            background: #333;
            color: #fff;
        }

        .btn-number:hover,
        .btn-decimal:hover {
            background: #444;
        }

        .btn-operator {
            background: #ff9500;
            color: #fff;
        }

        .btn-operator:hover {
            background: #ffaa33;
        }

        .btn-clear {
            background: #d4d4d2;
            color: #000;
        }

        .btn-clear:hover {
            background: #e5e5e3;
        }

        .btn-equals {
            background: #ff9500;
            color: #fff;
            grid-column: span 2;
        }

        .btn-equals:hover {
            background: #ffaa33;
        }

        .btn-zero {
            grid-column: span 2;
        }