body {
    font-family: Arial, sans-serif;
    font-size: 18px;
    line-height: 1.6;
    margin: 0;
    padding: 0;
    background-color: #004747;
}

.container {
    background-color: #012a29;
    max-width: 800px;
    margin: 0 auto;
}

header {
    background-color: #012a29;
    color: #ffffff;
    padding: 1rem;
}

h1, h2 {
    color: #004444;
    padding-bottom: 0.5rem;
}

.header_title {
    color: #ecfff0;
}

main {
    background-color: #edffff;
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem;
}

.date {
    color: #ffffef;
}

.article-image {
    max-width: 100%;
    height: auto;
    display: block;
    margin: 1rem 0;
}

ul {
    list-style: disc;
    padding-left: 1rem;
}

li {
    margin-bottom: 0.5rem;
}

a {
    text-decoration: none;
    color: #29a348;
    font-weight: bold;
}

a:hover {
    color: #29a348;
    text-decoration: underline;
}

.contents-title {
    font-weight: bold;
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

#article-navigation {
    display: flex;
    justify-content: space-between;
    margin-top: 1rem;
}

.previous-article a,
.next-article a {
    text-decoration: none;
    color: #29a348;
    font-weight: bold;
}

.previous-article a:hover,
.next-article a:hover {
    color: #29a348;
    text-decoration: underline;
}

@media screen and (max-width: 768px) {
    header,
    main {
        padding: 1rem;
    }
}