body {
    font-size: 2.5vh;
    margin: 0;
    background-color: #fff8b0; 
    font-family: 'Roboto', sans-serif;
}

h1 {
    color: #333;
    text-align: center;
    margin: 0;
    padding: 1vh 0;
}

#calcContainer {
    width: 90%;
    max-width: 360px;
    height: auto;
    padding: 2vh;
    border: 3px solid #333;
    border-radius: 10px;
    margin: 2% auto;
    background-color: #fff9c4;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    display: flex;
    flex-direction: column;
    align-items: center;
}

.displayOperator {
    text-align: right;
    font-size: 2.5vh;
    height: 3vh;
    line-height: 0vh;
    padding: 1em;
    border: 1px solid #ffb74d;
    color: #333;
    border-radius: 10px;
    background-color: #fff3e0;
    margin: none;
    width: 100%;
    box-sizing: border-box;
}

.displayBox {
    text-align: right;
    font-size: 3vh;
    height: 4vh;
    line-height: 0vh;
    padding: 1em;
    border: 2px solid #ffb74d;
    color: #333;
    border-radius: 10px;
    background-color: #fff3e0;
    margin-bottom: 1vh;
    width: 100%;
    box-sizing: border-box;
}

#operationHistory {
    height: 2vh;
    font-size: 2vh;
    text-align: right;
    padding-right: 1.5vh;
    color: #666;
    background-color: #fffde7; 
    margin-bottom: 1vh;
    width: 100%;
    box-sizing: border-box;
}

table {
    width: auto; 
    border-collapse: collapse;
    margin: 0 auto; 
}

button {
    width: 8vh;
    height: 8vh;
    font-weight: bold;
    font-size: 2.5vh;
    color: #fff;
    background-color: #ffb74d;
    border-radius: 10px;
    border: none;
    margin: 0.5vh;
    transition: background-color 0.3s;
}

#backspaceBtn {
    background-image: url("../assets/back_remove.png");
    background-repeat: no-repeat;
    background-position: center;
    background-size: 1.7em;
}

button:hover {
    background-color: #ffcc80; 
    cursor: pointer;
}

.operator {
    background-color: #ffd54f;
}

.operator:hover {
    background-color: #ffe082; 
}

#equals {
    width: 100%;
    border-radius: 10px;
    background-color: #ffb74d; 
    height: 8vh;
    font-size: 2.5vh;
    font-weight: bold;
    color: #fff;
    border: none;
    margin: 0.5vh 0;
    transition: background-color 0.3s;
}

#equals:hover {
    background-color: #ffcc80; 
}