body {
    font-family: Arial, Helvetica, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f7f9fc;
    color: #222;
    line-height: 1.6;
}

header {
    background-color: #2c5d8a;
    color: white;
    padding: 25px;
    text-align: center;
}

header h1 {
    color: white;
    margin: 0;
}

nav {
    background-color: #16324f;
    padding: 12px;
    text-align: center;
}

nav a {
    color: white;
    text-decoration: none;
    margin: 0 14px;
    font-weight: bold;
}

nav a:hover {
    text-decoration: underline;
}

.container {
    width: 85%;
    margin: 25px auto;
    background-color: white;
    padding: 25px;
    border: 1px solid #ccc;
    box-sizing: border-box;
}

h1 {
    color: #1f4e79;
    text-align: center;
    font-size: 36px;
}

h2 {
    color: #2c5d8a;
    font-size: 28px;
}

h3 {
    color: #3b6d99;
    font-size: 22px;
}

p {
    font-size: 18px;
    margin-bottom: 15px;
}

.left {
    text-align: left;
}

.center {
    text-align: center;
}

.right {
    text-align: right;
}

.indent {
    text-indent: 40px;
}

.italic {
    font-style: italic;
}

.highlight {
    color: #8b0000;
    font-size: 19px;
    font-weight: bold;
}

img.main-image,
.main-image {
    width: 350px;
    max-width: 100%;
    height: auto;
    border: 3px solid #4c6f91;
    margin: 15px;
    transition: transform 0.3s ease;
}

.main-image:hover {
    transform: scale(1.03);
}

img.left-img {
    float: left;
    margin-right: 20px;
}

img.right-img {
    float: right;
    margin-left: 20px;
}

img.center-img {
    display: block;
    margin: 20px auto;
}

.transparent-img {
    opacity: 0.9;
}

.thumbnail {
    width: 160px;
    border: 2px solid #666;
    margin: 10px;
}

.image-block {
    margin: 20px 0;
}

.image-block figcaption {
    font-size: 14px;
    color: #555;
    margin-top: 8px;
    font-style: italic;
    text-align: center;
}

.clearfix::after {
    content: "";
    display: table;
    clear: both;
}

ul, ol {
    margin-left: 30px;
    font-size: 18px;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
}

caption {
    font-weight: bold;
    font-size: 20px;
    margin-bottom: 10px;
    color: #1f4e79;
}

table, th, td {
    border: 1px solid #444;
}

th, td {
    padding: 12px;
    text-align: center;
}

th {
    background-color: #dbe8f4;
}

footer {
    background-color: #16324f;
    color: white;
    text-align: center;
    padding: 15px;
    margin-top: 30px;
}

.email-link {
    color: #8b0000;
    font-weight: bold;
}

.reference-list li {
    margin-bottom: 12px;
}

.bookmark-link {
    display: inline-block;
    margin-top: 20px;
    background-color: #2c5d8a;
    color: white;
    padding: 10px 14px;
    text-decoration: none;
    border-radius: 4px;
}

.bookmark-link:hover {
    background-color: #1f4e79;
}

@media (max-width: 800px) {
    img.left-img,
    img.right-img {
        float: none;
        display: block;
        margin: 20px auto;
    }

    .container {
        width: 94%;
    }
}