body {
    margin: 0;
    background-color: #f0f0f3;
}

#main {
    display: flex;
    height: 100vh;
    justify-content: center;
    align-items: center;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

#calculator-container {
    border: solid 2px #bbb;
    height: 600px;
    width: 450px;
    background-color: #fff;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    border-radius: 10px;
}

#screen {
    border: solid 2px #eaeaea;
    background-color: #e6e6e6;
    margin: 32px;
    height: 140px;
    border-radius: 5px;
}

#small-line, #large-line {
    color: #333;
}

#small-line {
    text-align: right;
    margin: 10px 10px 5px 10px;
    font-size: 24px;
    height: 2em;
}

#large-line {
    text-align: right;
    margin: 10px;
    font-size: 56px;
    height: 1em;
}

#button-container {
    justify-content: space-between;
    display: flex;
    flex-wrap: wrap;
    margin: 0px 24px;
    width: 402px;
    height: 360px;
    gap: 5px;
}

button {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 60px;
    width: 95px;
    font-size: 18px;
    font-weight: bold;
    transition: background-color 0.3s, transform 0.1s;
}

button.operator, button.equals {
    background-color: #ff9500;
    color: #fff;
}

button.clear, button.sign, button.percent {
    background-color: #d4d4d2;
}

button.operand, button.decimal {
    background-color: #f2f2f2;
}

#zero {
    width: 197px;
}