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

.hidden {
    display: none;
}

html {
    background: #e0e0e0;
    color: #000;
}

body {
    font-size: 1.1rem;
    font-family: 'source sans pro', sans-serif;
    max-width: 800px;
    margin: 0 auto;
}

#main {
    background: #fff;
    padding: 20px;
    border-radius: 10px;
    margin: 20px 0 0 0;
    min-height: 40vh;
    box-shadow: 0 0 5px #000;
}

header h1 {
    margin: 0 0 20px 0;
}

h2 {
    margin: 15px 0;
}

h4 {
    margin: 20px 0 -10px 0;
}

p {
    margin: 15px 0;
}

li:nth-child(n + 2) {
    margin-top: 12px;
}

button,
input[type="button"],
input[type="submit"] {
    cursor: pointer;
}

#no-camera-msg {
    background: #e0e0e0;
    padding: 10px;
    border-radius: 5px;
}

hr {
    margin: 15px 0;
    height: 0px;
    background: none;
    border: 1px solid #aaa;
    border-width: 1px 0 0 0;
}

footer {
    padding: 20px 10px;
    color: #555;
    font-size: 0.9rem;
    text-align: center;
}

a {
    color: blue;
}

.main-links a:not(.hidden) {
    display: inline-block;
    padding: 5px 10px;
    margin-right: 10px;
    background: blue;
    color: #fff;
    font-weight: bold;
    border-radius: 10px;
    box-shadow: 0 0 5px #707070;
    text-decoration: none;
}

.main-links a:hover {
    text-decoration: underline;
}

img {
    max-width: 100%;
}