body {
    font-family: Arial, sans-serif;
    background: #f5f7fa;
    margin: 0;
    padding: 0;
}

.container {
    max-width: 700px;
    margin: 40px auto;
    background: #fff;
    box-shadow: 0 4px 20px #ccd6df;
    padding: 36px 24px;
    border-radius: 12px;
}

header, footer {
    text-align: center;
}

h1 {
    color: #334155;
}

h2, h3 {
    color: #2563eb;
}

ul {
    margin-left: 18px;
}

button, .back-link {
    background: #2563eb;
    color: #fff;
    padding: 14px 34px;
    border: none;
    border-radius: 7px;
    cursor: pointer;
    font-size: 1.12em;
    margin: 24px 0 0 0;
    text-decoration: none;
    display: inline-block;
    transition: background 0.2s;
}
button:hover, .back-link:hover {
    background: #1d4ed8;
}

.center {
    text-align: center;
}

article {
    line-height: 1.7;
    font-size: 1.1em;
    margin-bottom: 32px;
}

strong {
    color: #184ead;
}