* {
    margin: 0;
    padding: 0;
}

body {
    margin-top: 50px;
    background-color: rgb(207, 216, 218);
    display: flex;
    justify-content: center;
    align-items: center;
}

main {
    height: 580px;
    width: 300px;
    text-align: center;
    background: linear-gradient(45deg, rgb(255, 54, 138), rgb(255, 116, 2));
    margin: 10px auto;
    box-shadow: 5px 5px 10px rgb(167, 167, 167);
}

main p {
    padding: 3px;
    margin-bottom: 2px;
    color: rgb(230, 230, 230);
    font-size: 8px;
    font-family: Verdana, Geneva, Tahoma, sans-serif;
}

main span {
    color: rgb(255, 0, 0);
}

main .inp {
    display: flex;
    flex-direction: column;
    justify-content: stretch;
    width: 100%;
    height: 30%;
}

main .inp #inp-screen {
    color: rgb(255, 255, 255);
    font-family: Verdana, Geneva, Tahoma, sans-serif;
    font-size: 2rem;
    height: 50%;
    width: 270px;
    background: linear-gradient(86deg, rgb(255, 54, 138), rgb(255, 116, 2));
    border: none;
    outline-style: none;
    padding: 12px;
    /* overflow-x: visible; */
}

main .inp #out-screen {
    color: rgba(255, 255, 255, 0.6);
    font-family: Verdana, Geneva, Tahoma, sans-serif;
    font-size: 1rem;
    height: 50%;
    width: 270px;
    background: linear-gradient(49deg, rgb(255, 54, 138), rgb(255, 116, 2));
    border: none;
    outline-style: none;
    padding: 12px;
    /* overflow-x: visible; */
}

.btn {
    background-color: white;
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
}

.btn .top-btn {
    display: flex;
    align-items: stretch;
    width: 100%;
}

.top-btn button {
    color: rgb(100, 100, 100);
    font-size: 1.5rem;
    font-family: Verdana, Geneva, Tahoma, sans-serif;
    padding: 25px 15px;
    width: 25%;
    border: none;
}

.btn .num-btn {
    display: flex;
    flex-direction: row;
    width: 100%;
}

.btn .num-btn .num {
    display: flex;
    flex-wrap: wrap;
    width: 76%;
    margin: 0;
}

.btn .num-btn .num button {
    color: rgb(100, 100, 100);
    font-size: 1.5rem;
    padding: 25px 15px;
    width: 33%;
    background-color: white;
    border: none;
}

.btn .num-btn .operator-btn {
    display: flex;
    flex-direction: column;
    justify-content: stretch;
    height: 100%;
    margin: 0;
}

.btn .num-btn .operator-btn button {
    color: rgb(100, 100, 100);
    font-size: 1.5rem;
    padding: 25px 15px;
    width: 75px;
    margin: 0;
    border: none;
}

button:hover {
    background-color: rgb(207, 207, 207);
}

button:active {
    background-color: rgb(175, 175, 175);
}

.num-btn .num button:hover {
    background-color: rgb(207, 207, 207);
}

.num-btn .num button:active {
    background-color: rgb(175, 175, 175);
}