body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-color: #555555;
    font-family: Arial, sans-serif;
}

.calculator {
    width: 340px;
    margin: 30px auto;
    padding: 25px;
    background: #444444; 
    border-radius: 12px;
}

input {
    width: 100%;
    height: 40px;
    font-size: 20px;
    text-align: right;
    margin-bottom: 20px;
    padding: 5px;
    background-color: #DDDDDD; 
    color: #333333; 
    border: 1px solid #AAAAAA; 
}

.buttons button {
    border: none;
    border-radius: 50%; 
    background: #777777; 
    color: #FFFFFF; 
    font-size: 18px;
    cursor: pointer;
}

button.buttons1 {
    background: #b5e508 !important; 
    color: #ff0000 !important; 
    grid-column: 4;
    grid-row: 1 / span 2;
    height: calc(60px * 2 + 12px);
    align-self: start;
    border-radius: 30px; 
    font-size: 30px;
    font-weight: bold;
}

.equal-button {
    background: #b5e508 !important; 
    color: #d61212 !important; 
    border-radius: 50%; 
    font-size: 35px;
    font-weight: bold;
}

.buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    grid-auto-rows: 60px;
}

.buttons button:hover {
    background-color: #999999; 
}