body {
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: rgb(255, 255, 255);
    padding: 0%;
    margin: 0%;
    height: 100vh;
}

.calculator {
    background-color: rgb(29, 31, 31);
    padding: 20px 20px 0px 20px;
    width: 350px;
    border: 3px solid rgb(0, 0, 0);
    border-radius: 8px;
    box-shadow: 10px 20px 40px black;
}

.display {
    border: 3px solid rgb(255, 255, 255);
    margin: 0 auto;
    box-sizing: border-box;
    width: 100%;
    text-align: right;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 15px;
    border-radius: 8px;
    height: 70px;
    font-weight: 600;
    background-color: rgb(24, 44, 25);
    margin-bottom: 20px;
    font-size: 50px;
    color: black
}

.buttons {
    padding: 25px;
    gap: 10px;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    border: 0.1px solid grey;
    border-radius: 8px;
    padding: 10px;
    transition: all 0.1s ease;
}

.operator {
    background-color: rgb(0, 174, 255);
}

button {
    border: 2px solid black;
    border-radius: 12px;
    padding: 20px;
    font-size: 20px;
    font-weight: 700;
    background-color: rgb(224, 222, 222);
}

.credits {
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 15px;
    box-sizing: border-box;
    margin-bottom: 0px;
    text-align: center;
    margin: 10px 0px 10px 0px;
    color: rgb(97, 96, 96);
    opacity: 30%;
    text-decoration: none;
    font-weight: 300;
    font-family: Verdana, Geneva, Tahoma, sans-serif;
}

.equal {
    background-color: rgb(255, 136, 0);
}

.operator:hover {
    background-color: rgb(0, 81, 255);
}

.equal:hover {
    background-color: rgb(255, 102, 0);
}

.number:hover {
    background-color: rgb(131, 130, 130);
}

.buttons :hover {
    cursor: pointer;
}

.buttons :active {
    transform: scale(0.95);
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2) inset;
}

.credits :hover {
    cursor: pointer;
    text-decoration: underline;
}

@media screen and (max-width: 400px) {
    .calculator {
        width: 100%;
        padding: 10px 10px 0px 10px;
    }

    .display {
        font-size: 30px;
        height: 50px;
    }

    button {
        padding: 15px;
        font-size: 16px;
    }

    .buttons {
        padding: 15px;
    }
    .credits {
        font-size: 14px;
    }
}

@media (max-width: 300px) {
    .calculator {
        width: 100%;
        padding: 15px 15px 0px 15px;
    }
    .display {
        font-size: 20px;
        height: 40px;
    }
    button {
        padding: 10px;
        font-size: 14px;
    }
    .credits {
        font-size: 13px;
    }
}

@media (max-width: 200px) {
    .calculator {
        width: 100%;
        padding: 10px 10px 0px 10px;
    }
    .display {
        font-size: 16px;
        height: 30px;
    }
    button {
        padding: 5px;
        font-size: 12px;
    }
    .credits {
        font-size: 12px;
    }
}

@media (max-width: 150px) {
    .calculator {
        width: 100%;
        padding: 5px 5px 0px 5px;
    }
    .display {
        font-size: 12px;
        height: 20px;
    }
    button {
        padding: 3px;
        font-size: 10px;
    }
    .credits {
        font-size: 11px;
    }
}