* {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}

body {
    height: auto;
    display: flex;
    align-items: center;
    justify-content: center;
    background-image: url(../img/pencils.webp);
    background-size: 100%;
}

.calculator {
    flex: 0 0 31%;
    padding-top: 10px;
    padding-bottom: 10px;
    background: #665959;
    border-radius: 18px;
    margin-top: 4em;
    margin-bottom: 4em;
}

.screen {
    width: 100%;
    padding: 0.5em;
    font-size: 3rem;
    background: #362e2e;
    border: none;
    color: #18ff18;
    border: 8px solid #665959;
    border-top-left-radius: 12px;
    border-top-right-radius: 12px;
}

.screen:focus {
    outline: none !important;
}

.buttons {
    display: flex;
    flex-wrap: wrap;
    transition: all 0.5s linear;
    background: #665959;
    padding: 0.5em;
    gap: 0.5em;
    border-bottom-left-radius: 25px;
    border-bottom-right-radius: 25px;
}

.btn:hover {
    background: purple;
    transition: all 2s ease;
}

.btn-orange {
    font-size: 4rem;
    flex: 0 0 23.5%;
    padding: 0 1.2rem;
    border-radius: 25px;
    background-color: orange;
}

.btn-gray {
    font-size: 4rem;
    flex: 0 0 23.5%;
    padding: 0 1.2rem;
    border-radius: 25px;
}

.btn-grays {
    font-size: 4rem;
    flex: 0 0 49%;
    padding: 0 1.2rem;
    border-radius: 25px;
}

.btn-equal {
    font-size: 4rem;
    flex: 0 0 49%;
    padding: 0 1.2rem;
    border-radius: 25px;
    background-color: green;
}

.btn-clear {
    font-size: 4rem;
    flex: 0 0 49%;
    padding: 0 1.2rem;
    border-radius: 25px;
    background-color: red;
}

@media (min-width: 418px) and (max-width: 425px) {
    .calculator{
        flex: 0 0 93%;
    }
}

@media (min-width: 418px) and (max-width: 425px) {
    .screen{
        font-size: 3rem;
    }
}

@media (min-width: 418px) and (max-width: 425px) {
    .btn-orange{
        flex: 0 0 23.4%;
    }
}

@media (min-width: 418px) and (max-width: 425px) {
    .btn-gray{
        flex: 0 0 31.8%;
    }
}

@media (min-width: 418px) and (max-width: 425px) {
    .btn-grays{
        flex: 0 0 66%;
    }
}

@media (min-width: 418px) and (max-width: 425px) {
    .btn-clear{
        flex: 0 0 48% !important;
    }
}

@media (min-width: 418px) and (max-width: 425px) {
    .btn-equal{
        flex: 0 0 49% !important;
    }
}

@media (min-width: 320px) and (max-width: 418px) {
    .calculator{
        flex: 0 0 95%;
    }
}

@media (min-width: 320px) and (max-width: 418px) {
    .screen{
        font-size: 3rem;
    }
}

@media (min-width: 320px) and (max-width: 418px) {
    .btn-orange{
        flex: 0 0 31%;
    }
}

@media (min-width: 320px) and (max-width: 418px) {
    .btn-gray{
        flex: 0 0 31%;
    }
}

@media (min-width: 320px) and (max-width: 418px) {
    .btn-grays{
        flex: 0 0 31%;
    }
}

@media (min-width: 320px) and (max-width: 418px) {
    .btn-equal{
        flex: 0 0 49%;
    }
}

@media (min-width: 320px) and (max-width: 418px) {
    .btn-clear{
        flex: 0 0 48%;
    }
}