style.css

/* CSS Class */
* {
    box-sizing: border-box;
}

h1 {
    margin: 0;
}

.section.center {
    display: flex;
    justify-content: center;
    flex-flow: row wrap;
}

.jumbotron-fluid {
    padding: 10px;
}

.center h2 {
    text-align: center;
}

.center li {
    text-align: center;
}

li {
    list-style: none;
}

/* -------- */
.header-bg {
    background-color: #f76c5e;
}

.jumbotron-fluid {
    /* background-color: #f76c5e; */

    text-align: center;
}

.jumbotron-fluid h1 {
    color: white;
    font-size: 4rem;
    margin: 10px;
}

.jumbotron-fluid .lead {
    font-size: 2rem;
}

.jumbotron-fluid p {
    color: white;

}

#footer {
    background-color: blue;
    text-align: center;
    color: red;
    bottom: 0px;
}

.card {
    box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2);
    max-width: 300px;
    margin: 10px;
    text-align: center;
}

.card img {
    width: 100px;
    height: 100px;
    border-radius: 50%;
}

.card h1 {
    font-size: 22px;
}

.card .title {
    color: grey;
    font-size: 14px;
}

button {
    border: none;
    outline: 0;
    display: inline-block;
    padding: 8px;
    color: white;
    background-color: #000;
    text-align: center;
    cursor: pointer;
    width: 100%;
    font-size: 18px;
}

a {
    text-decoration: none;
    font-size: 22px;
    color: black;
}

button:hover,
a:hover {
    opacity: 0.7;
}

.list-grid ol {
    column-count: 3;
}

@media (max-width: 768px) {
    .jumbotron-fluid h1 {
        font-size: 4rem;
    }
}