@import url('https://fonts.googleapis.com/css2?family=Roboto:ital,wght@0,100..900;1,100..900&display=swap');

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

body {
    font-family: "Roboto", sans-serif;    
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 20px;
}

.calculator {
    border-radius: 5px;
    height: 60%;
    width: 340px;
    display: flex;
    flex-direction: column;
    background-color: #1b263b;
    box-shadow: rgba(0, 0, 0, 0.3) 0px 19px 38px, rgba(0, 0, 0, 0.22) 0px 15px 12px;
}

.display {
    padding: 10px;
    flex: 1;
    display: flex;
    flex-direction: column;
    border-bottom: 2px solid rgba(255, 255, 255, 0.2);
}
.upper-display,
.lower-display {
    flex: 1;
    display: flex;
    align-items: flex-end;
    justify-content: flex-end;    
}

.upper-display {
    color: lightgray;
    font-size: 18px;
}

.lower-display {
    color: white;
    font-size: 45px;
    font-weight: bold;    
}

.buttons {    
    padding: 10px;
    flex: 3;
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.all-clear-btn,
.clear-btn,
.delete-left-btn {
    background-color: #023e8a;
}

.all-clear-btn:hover,
.clear-btn:hover,
.delete-left-btn:hover {
    background-color: #035ed4;
}

.number-btn,
.plus-minus-btn,
.decimal-btn {
    background-color: #415a77;
}

.number-btn:hover,
.plus-minus-btn:hover,
.decimal-btn:hover {
    background-color: #3e4958;
}

.operator-btn {
    background-color: #3e4958;
}

.operator-btn:hover {
    background-color: #415a77;
}

.equal-btn {
    background-color: #035ed4;
}

.equal-btn:hover {
    background-color: #023e8a;
}

.btn-row {    
    flex: 1;    
    display: flex;
    gap: 5px;
}

button {
    flex: 1;
    font-size: 20px;
    border-radius: 5px;
    border: none;
    background-color: #e0e1dd;
    color: white;
    font-weight: bold;
    box-shadow: rgba(255, 255, 255, 0.2) 0px 0px 0px 1px inset, rgba(0, 0, 0, 0.9) 0px 0px 0px 1px;
}

.shortcuts {      
      border: 1px solid #ccc;
      background: #f9f9f9;
      padding: 20px;
      border-radius: 5px;
}

.shortcuts p {
    margin: 10px 0;
}

.shortcuts kbd {
      background: #eee;
      border: 1px solid #ccc;
      padding: 2px 5px;
      border-radius: 3px;
      font-family: monospace;
}