*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body{
    background-color: #555;
    margin: 2rem;
    padding: 2em;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.container{
    width: 100%;
    max-width: 400px;
    text-align: center;
}

h1{
    margin: 2rem;
}

.calculatrice{
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    border-radius: 10px;
    box-shadow: 10px 5px 10px 10px black;
    padding: 2rem;
    background-color: #999;
}

.resultat input{
    width: 300px;
    padding: 1rem;
    margin: 1em;
    box-shadow: 2px 2px 2px 2px #555;
    background-color: white;
    border-radius: 5px;
    text-align: right;
}
.boutons{
    width: 100%;
    display: grid;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    grid-template-columns: repeat(4, 1fr);

}

button{
    padding: 1em;
    border-radius: 5px;
    cursor: pointer;
}

button:hover{
    background-color: #ddd;
}

button:active {
    background-color: #555;
    color: #ddd;
    outline: none;
}