body {
    font-family: Verdana, Geneva, Tahoma, sans-serif;
    background-color: #ededed;
    color: #333;
    margin: 0;
    padding: 0;
    text-align: center;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 40px;
    background-color: #31394c;
    color: #ededed;
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-left {
    font-size: 1.5em;
    font-weight: bold;
}

.header-right a {
    color: #ededed;
    text-decoration: none;
    margin-left: 20px;
    font-weight: bold;
    transition: color 0.3s;
}

.header-right a:hover {
    color: #7a7f84;
}

main {
    max-width: 700px;
    margin: 30px auto;
    padding: 0 20px;
}

h1, h2, h3 {
    margin: 20px 0 15px 0;
}

p {
    font-size: 1.1em;
    margin: 10px 0 20px 0;
}

ul {
    list-style-type: none;
    padding: 0;
    margin: 0 auto 20px auto;
    max-width: 400px;
}

li {
    background-color: #ffffff;
    margin: 8px 0;
    padding: 10px 15px;
    border-radius: 5px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

a {
    color: #2c3e50;
    font-weight: bold;
}

a:hover {
    color: #7a7f84;
}

section {
    margin-bottom: 40px;
}