* {
  margin: 0px;
  padding: 0px;
  text-decoration: none;
  outline: none;
  box-sizing: border-box;
}

body {
  background: linear-gradient(-40deg, #2c5049, #345e5c, #2c5046, #4c685f);
  font-family: monospace;
  display: flex;
  height: 100vh;
  justify-content: center;
  align-items: center;
}

.container {
  width: 600px;
  height: 400px;
  border-radius: 7px;
  background-color: #ffffff;
  box-shadow: rgba(0, 0, 0, 0.4) 0px 2px 4px,
    rgba(0, 0, 0, 0.3) 0px 7px 13px -3px, rgba(0, 0, 0, 0.2) 0px -3px 0px inset;
}
.container h1 {
  margin-top: 10px;
  padding: 10px;
  font-family: Arial, Helvetica, sans-serif;
  text-align: center;
  font-size: 30px;
}

table {
  display: flex;
  justify-content: center;
  align-items: center;
  border-collapse: collapse;
}

.calculator .display {
  padding: 10px;
  width: 20em;
  margin: 6px;
  border: 2px solid black;
  box-shadow: 5px 5px gray;
  font-size: 20px;
  font-family: monospace;
  font-weight: bold;
  text-align: right;
}

.calculator button {
  cursor: pointer;
  padding: 10px;
  margin: 3px;
  width: 85px;
  font-size: 16px;
  background-color: #dfdfdf;
  border: 2px solid black;
  box-shadow: 5px 5px rgba(128, 128, 128, 0.762);
  color: #000000;
}

.calculator .btn-equal {
  background-color: #3d5745;
  color: white;
}
.calculator button:hover {
  background-color: #cdcdcd;
}

.calculator button:active {
  transform: translate(1px, 1px);
  box-shadow: 5px 2px #80808098;
}

@media screen and (max-width: 460px) {
  body {
    background: white;
    align-items: flex-start;
  }

  .container {
    box-shadow: none;
    width: auto;
    height: auto;
  }

  .calculator .display {
    width: 18em;
  }

  .calculator button {
    width: 75px;
  }
}