body {
    background-color: black;
    margin: 0;
    height: 100vh;
}

main {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100%;
}

.main-container {
    border: 1px solid rgb(138, 138, 138);
    padding: clamp(1rem, 3vw, 2rem);
    border-radius: 1rem;
    width: 100%;
    max-width: 300px;
}

.output {
    color: white;
    min-height: 40px;
    font-size: clamp(1.5rem, 5vw, 2rem);
    margin-top: 0;
    background-color: rgb(26, 26, 26);
    padding: 10px 15px;
}

.first-container,
.second-container,
.third-container,
.fourth-container,
.fifth-container {
    display: flex;
    margin-top: 10px;
    gap: clamp(5px, 2vw, 10px);
}

.btn-number {
    border-radius: 50px;
    color: white;
    background-color: rgb(73, 73, 73);
}

.btn-number2 {
    border-radius: 50px;
    color: white;
    background-color: rgb(255, 136, 0);
}

.btn-number3 {
    border-radius: 50px;
    font-size: 0.7rem;
    color: white;
    background-color: rgb(255, 136, 0);
}

.btn-number,
.btn-number2,
.btn-number3 {
    width: clamp(50px, 15vw, 70px);
    height: clamp(50px, 15vw, 70px);
    font-size: clamp(1rem, 2.5vw, 1.3rem);
    border: none;
    cursor: pointer;
}

button:active {
    transform: scale(0.95);
}

button:hover {
    filter: brightness(1.2);
}

@media (max-width: 400px) {
    .main-container {
        max-height: 100%;
        max-width: 250px;
    }
}