styles.css

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

body {
    font-family: Arial, Helvetica, sans-serif;
}

nav {
    width: 100%;
    height: 70px;
    position: relative;
    z-index: 1000;
    position: fixed;
}

ul {
    height: 100%;
    list-style-type: none;
    display: flex;
    justify-content: center;
    align-items: center;
}

li {
    font-size: 20px;
    margin: 0 20px;
    cursor: pointer;
    color: #f1f1f1;
}

.accueil {
    height: 70vh;
    width: 100%;
    background-color: #0C273C;
}

@media screen and (max-width: 450px) {
    .accueil {
        height: 85vh;
    }
}

.fond-curvy {
    width: 100%;
    position: absolute;
    left: 0;
    bottom: 5%;
    display: block;
}

.contenu {
    position: relative;
    z-index: 1000;
} 

h1 {
    font-size: 70px;
    padding: 200px 0 0 10vw;
    position: relative;
    right: 8px;
    color: #f1f1f1;
}

p {
    font-size: 30px;
    padding: 0 0 0 10vw;
    margin: 7px 0;
    color: #f1f1f1;
}

button {
    margin: 20px 0 0 10vw;
    padding: 12px;
    font-size: 20px;
    width: 150px;
    border-radius: 5px;
    cursor: pointer;
    border: none;
}

.laptop {
    width: 30vw;
    height: 250px;
    position: absolute;
    top: 100px;
    right: 12%;
}