style.css

/* Level 1 */

* {
    box-sizing: border-box;
}
body {
    background-color: hsl(233, 47%, 7%);
    font-size: 15px;
    margin: 0;
}
main {
    background-color: hsl(275, 100%, 25%);
    border-radius: 7.5px;
    margin: 20% 7.5%;
}
img {
    opacity: 0.4;
}
#ih-mobile {
    border-radius: 7.5px 7.5px 0 0;
    display: block;
    width: 100%;
}
#card-body {
    background-color: hsl(244, 38%, 16%);
    border-radius: 0 0 7.5px 7.5px;
    padding: 7.5%;
    text-align: center;
}
#ih-desktop {
    border-radius: 0 7.5px 7.5px 0;
    display: none;
    width: 50%;
}

/* Level 2 */

h1, h2, p {
    font-family: 'Inter', sans-serif;
}
h1, h2 {
    color: hsl(0, 0%, 100%);
}
p {
    color: hsla(0, 0%, 100%, 0.75);
    line-height: 1.75em;
}
ul {
    list-style-type: none;
    padding: 0;
}
li {
    margin-top: 12%;
}
h2 {
    margin: 3% 0;
}
li > div {
    color: hsla(0, 0%, 100%, 0.6);
    font: .8em 'Lexend Deca', sans-serif;
}

/* Level 3 */

@media only screen and (min-width: 768px) {
main {
    font-size: 1.075em;
    margin: 12%;
}
#ih-mobile {
    display: none;
}
#card-body {
    border-radius: 7.5px 0 0 7.5px;
    padding: 5% 10% 5% 7%;
    text-align: left;
    width: 50%;
}
#ih-desktop {
    display: block;
}
p {
    line-height: 1.5em;
}
main, ul {
    display: flex;
}
h2 {
    margin: 5% 0;
}
li {
    width: 33%;
}
}