index.css

body {
    margin: 0;
    padding: 0;
}

.logo {
    width: 150px;
}

.avatar {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    margin-top: 10px;
}

h2 {
    font-size: 20px;
    font-weight: 600;
    display: block;
    margin: 10px
}

h2 span {
    display: block;
    font-size: smaller;
    font-weight: 200;
}

h1,
h3 {
    margin: 0;
}

.margin {
    margin-left: 25px;
}

header .avatar {
    margin-right: 25px;
}

section h3,
p {
    margin-left: 10px;
}

p {
    font-weight: bold;
}

p span {
    font-weight: 200;
}

/* Containers */

.container {
    min-width: 360px;
    max-width: 600px;
    margin: 5px auto;
}

.header-container {
    margin: 5px auto;
    display: flex;
    justify-content: space-between;
    border-bottom: 1px solid lightgray;
    background-color: white;
}

.flex-container {
    display: flex;
    justify-content: flex-start;
}

.container-end {
    border-bottom: 30px solid lightgray;
    display: block;
    margin: auto;
}

.main-image {
    min-width: 360px;
    max-width: 800px;
    width: 100%;
    margin: 0 auto;
    display: block;
}

/* Buttons actions and styles */
.button {
    width: 25px;
    padding: 5px;
    cursor: pointer;
}

.button:hover,
.button:focus {
    filter: opacity(.5) drop-shadow(0 0 0 white);
}

.button:active {
    filter: opacity(.5) drop-shadow(0 0 0 red);
}