*{
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}
body{
    background-color: #0F183D;
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
    height: 100vh;
}
.calculator{
    background-color: #f2f2f2;
    padding: 20px;
    max-width: 400px;
    margin: 0 auto;
    border: 1px solid #ccc;
    box-shadow: 0 2px 5px rgba(0, 0, 0, .3);
    border-radius: 5px;
    margin-top: 40px;
}
#result{
    width: 100%;
    padding: 10px;
    font-size: 24px;
    border: none;
    box-shadow: 0 2px 5px rgba(0, 0, 0, .3) inset;
    border-radius: 5px;
    text-align: right;
}
.buttons{
    display: grid;
    grid-template-columns: repeat(4,2fr); 
    grid-gap: 10px;
    margin-top: 20px;
}
button{
    padding: 10px;
    font-size: 24px;
    border: none;
    box-shadow: 0 2px 5px rgba(0, 0, 0, .3);
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s ease;

}
button:hover{
    background-color: #ddd;
}

.clear{
    background-color: #ff4136;
    color: #fff;

}
.number, .decimal{
    background-color: #fff;
    color: #333;
}
.operator{
    background-color: #0074d9;
    color: #fff;
}
.equals{
    background-color: #02ff70;
    grid-row: span 3;
    color: #fff;
}