body {
	margin: 40px auto;
	max-width: 690px;
	line-height: 1.6;
	font-size: 18px;
	color: #444;
	padding: 0 10px;
}

header {
	padding: 1rem;
}

h1,
h2,
h3 {
	line-height: 1.2
}

div {
	padding: 1rem;
}

.nav-logo {
	height: 150px;
	vertical-align: middle;
}

nav {
	padding: 1rem;
	text-align: center;
}

nav a {
	text-decoration: none;
	padding: 1rem 1.5rem;
	font-size: 18px;
	font-weight: bold;
}

.active {
	background-color: #cfd0d1;
}

@media screen and (max-width: 690px) {
	nav {
		display: flex;
		flex-direction: column;
	}
}

button {
	color: white;
	border: none;
	font-size: 16px;
	padding: 10px 20px;
	border-radius: 5px;
	cursor: pointer;
}

.complete-btn {
	background-color: #28a745;
	transition: background 0.3s ease-in-out;
}

.complete-btn:hover {
	background-color: #218838;
}

.complete-btn:disabled {
	background-color: #6c757d;
	cursor: not-allowed;
}

.twitter-btn {
	background-color: #1DA1F2;
	transition: background 0.3s ease-in-out;
}

.twitter-btn:hover {
	background-color: #0d8ddb;
}