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

body {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;

    min-height: 100vh;
    padding-top: 200px;
    margin: 0;

    font-family: "Open Sans", sans-serif;
    font-size: 18px;
    font-weight: 300;
    color: #9eaebb;
    background-color: #f9faff;
}

a,
button {
    font: inherit;
    color: inherit;
}

.share-btn {
    border-radius: 100px;
    margin: auto 0;
    position: relative;
    transition: box-shadow 300ms ease;
}

.share-btn:hover {
    box-shadow: 0 10px 55px rgba(61, 129, 251, 0.35);
}

.share-btn > button {
    display: block;
    width: 480px;
    padding: 0;
    border: 3px solid #dfe6e7;
    border-radius: 100px;

    font-size: 30px;
    font-weight: 800;
    line-height: 120px;
    letter-spacing: -1px;
    background-color: #fff;
    outline: none;
    cursor: pointer;
    transition: border-color 250ms ease;
}

.share-btn > button:hover,
.share-btn > button:focus {
    border-color: #3d81fb;
}

.share-btn .social-links {
    padding: 30px;
    border-radius: 100px;
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    font-size: 0;
    text-align: center;
    background-color: #3d81fb;
    pointer-events: none;
    overflow: hidden;
    opacity: 0;
    transition: opacity 300ms ease;
}

.share-btn:hover .social-links {
    pointer-events: auto;
    opacity: 1;
}

.share-btn .social-links a {
    display: inline-block;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    margin: 0 10px;
    background: #fff center center no-repeat;
    background-size: 80%;
    transform: translateY(120px);
    transition: transform 300ms cubic-bezier(0.17, 0.04, 0.43, 1.59);
}

.share-btn .social-links a:hover,
.share-btn .social-links a:focus {
    background-color: #dae7fa;
}

.share-btn:hover .social-links a {
    transform: translateY(0);
}

.share-btn .social-links a.facebook {
    background-image: url("images/facebook.png");
}

.share-btn .social-links a.twitter {
    background-image: url("images/twitter.png");
    transition-delay: 50ms;
}

.share-btn .social-links a.linkedin {
    background-image: url("images/linkedin.png");
    transition-delay: 100ms;
}

.share-btn .social-links a.email {
    background-image: url("images/email.png");
    transition-delay: 150ms;
}

.share-btn .social-links a.website {
    background-image: url("images/website.png");
    transition-delay: 200ms;
}

footer {
    padding: 100px 10px;
    font-size: 16px;
    text-align: center;
}

footer p {
    margin: 0.5em 0;
}

footer a {
    color: #3d81fb;
}