*{
    padding: 0;
    margin: 0;
    box-sizing: border-box;
    font-family: 'poppins',sans-serif;
}

body{
    width: 100%;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background: linear-gradient(45deg , #0a0a0a , #3a4452);
}

.main{
    gap: 200px;
    display: flex;
}

.main h1{
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fb7c14;
    font-size: 60px;
}

.cal{
    border: 1px solid #717377;
    padding: 20px;
    border-radius: 16px;
    background-color: transparent;
    box-shadow: 0px 3px 15px rgba(113,115,119,0.9);
}

input{
    width: 320px;
    border: none;
    background-color: transparent;
    padding: 24px;
    margin: 10px;
    box-shadow:  0px 3px 15px rgba(84,84,84,0.1);
    font-size: 40px;
    text-align: right;
    cursor: pointer;
}

button{
    width: 60px;
    height: 60px;
    border-radius: 50%;
    margin: 10px;
    border: none;
    background-color: transparent;
    color: #ffffff;
    font-size: 20px;
    box-shadow:  -8px -8px 15px rgba(255,255,255,0.1);
    cursor: pointer;
}

.equal{
    background-color: #fb7c14;
}

.operator{
    color: #6dee0a
}

@media (min-width:821px) and (max-width:1024px) {
    .main {
        gap: 100px; 
    }

    .main h1 {
        font-size: 50px;
    }

    .cal {
        width: 80%;
        max-width: 400px;
    }

    input {
        width: 100%;
        font-size: 32px;
    }

    button {
        width: 55px;
        height: 55px;
        font-size: 18px;
    }
}

@media (min-width:768px) and (max-width:820px) {
    .main {
        flex-direction: column;  
        align-items: center;
        gap: 50px;
    }

    .main h1 {
        font-size: 45px;
        text-align: center;
    }

    .cal {
        width: 90%;
        max-width: 400px;
    }

    input {
        width: 100%;
        font-size: 30px;
    }

    button {
        width: 55px;
        height: 55px;
        font-size: 18px;
    }
}

@media (min-width:451px) and (max-width:767px) {
    .main {
        flex-direction: column; 
        align-items: center;
        gap: 40px;
    }

    .main h1 {
        font-size: 40px;
        text-align: center;
    }

    .cal {
        width: 90%;
        max-width: 350px;
    }

    input {
        width: 100%;
        font-size: 28px;
    }

    button {
        width: 40px;
        height: 40px;
        font-size: 16px;
    }
}

@media (max-width:450px) {
    .main {
        flex-direction: column;  
        align-items: center;
        gap: 30px;
    }

    .main h1 {
        font-size: 30px;
        text-align: center;
    }

    .cal {
        width: 95%;
        max-width: 300px;
        padding: 10px;
        padding-left: 20px;
    }

    input {
        width: 100%;
        font-size: 24px;
        padding: 18px;
    }

    button {
        width: 40px;
        height: 40px;
        font-size: 14px;
        margin: 8px;
    }
}