*{
    box-sizing: border-box;
}

body{
    font-family: sans-serif;
    margin: 0;
    padding: 1rem;
    background: #f4f4f4;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.calculator{
    max-width: 400px;
    width: 100%;
    background: #fff;
    padding: 1rem;
    border-radius: 10px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

.display{
    font-size: 2rem;
    margin-bottom: 0.5rem;
    padding: 0.5rem;
    border: 1px solid #ddd;
    border-radius: 5px;
    text-align: right;
    background: #fefefe;
    height: 60px;
}

.buttons{
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0.5rem;
}

.buttons button{
    padding: 1rem;
    font-size: 1.2rem;
    border: none;
    border-radius: 8px;
    background: #eee;
    cursor: pointer;
}

.buttons button.operator{
    background: #ffd966;
}

.buttons button.equal{
    background:#85e085
}

.buttons button.clear{
    background: #f08080;
}


.history{
    margin-top: 1rem;
    max-height: 200px;
    overflow-y: auto;
    font-size: 0.9rem;
    background: #fff;
    padding: 0.5rem;
    border-radius: 5px;
}

.history-entry{
    padding: 0.3rem 0;
    border-bottom: 1px solid #ddd;
}