* {
    box-sizing: border-box;
}

body {
    font-family: Arial, Helvetica, sans-serif;
    background-color: #f6f7f8;
    color: #333;
    margin: 0;
    padding: 0;
}

.container {
    max-width: 800px;
    margin: 60px auto;
    background: #ffffff;
    padding: 40px;
    border-radius: 8px;
}

h1 {
    margin-top: 0;
    font-size: 26px;
}

p, li {
    line-height: 1.6;
    font-size: 15px;
}

ul {
    padding-left: 20px;
}

.nav-back {
    margin-top: 40px;
    text-align: center;
}

.nav-back a {
    display: inline-block;
    padding: 10px 22px;
    background-color: #007bff;
    color: #ffffff;
    text-decoration: none;
    border-radius: 4px;
    font-size: 14px;
}

.nav-back a:hover {
    opacity: 0.9;
}