*{
  margin: 0;
  padding: 0;
  box-sizing: border-box; 
  font-family: 'Arial', Sans-Serif;
}
.container {
  width: 100%;
  min-height: 100vh; 
  background: linear-gradient(-45deg, #b5e7fd 0 1% , #fec9e2 60%);
  text-align: center;
  padding-block: 30px;
  display: flex;
  flex-direction: column;
  align-items: center;
}
.title{
  opacity: .6;
  margin-bottom: 40px;
}
.app{
  width: 90%;
  max-width: 450px;
}
.inputCon{
  margin: 10px auto 10px;
  border: 1px solid #fee9e9;
  background-color: rgba(255, 255,255,.2);
  backdrop-filter: blur(10px);
  border-radius: 10px;
}
.inputCon input{
  border: none;
  outline: none;
  background-color: transparent;
  font-size: 3.5rem;
  color: rgba(0, 0,0,.6);
  padding: 30px 20px;
  width: 100%;
  text-align: right;
  box-shadow: 0 0 8px 3px rgba(255, 255,255,.2);
}
.keys{
  width: 100%;
  padding: 20px 0;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
}
button{
  background-color: rgba(255, 255,255,.2);
  backdrop-filter: blur(10px);
  border-radius: 10px;
  outline: none;
  border: 1px solid #fee9e9;
  height: 75px;
  font-size: 1.5rem;
  font-weight: bold;
  color: rgba(0, 0,0,.6);
  box-shadow: -2px -2px 4px rgba(255, 255,255,.2), 2px 2px 4px 1px rgba(0, 0,0,.1);
}
button:nth-child(16){
  grid-column-start: 4;
  grid-row-start: 4;
  grid-row-end: 6;
  height: auto;
  background-color: rgba(253,181,222,0.2);
}