styles_css = '''
body {
  font-family: 'Open Sans', sans-serif;
  color: #333;
  line-height: 1.6;
  font-size: 16px;
  background-color: #fff;
}

h1, h2, h3, h4 {
  color: #0066cc;
  font-weight: 600;
  margin-top: 1.2em;
}

pre code {
  background-color: #f8f9fa;
  border-radius: 8px;
  padding: 1em;
  display: block;
}

code {
  background-color: #f0f0f0;
  color: #c7254e;
  border-radius: 4px;
  padding: 2px 5px;
}

img {
  border-radius: 8px;
  max-width: 100%;
  display: block;
  margin: 1em auto;
}

table {
  border-collapse: collapse;
  width: 100%;
  margin: 1em 0;
}
th, td {
  border: 1px solid #ddd;
  padding: 0.6em;
}
th {
  background-color: #f2f2f2;
  text-align: left;
}

.note, .tip, .warning, .important {
  border-left: 4px solid #007BFF;
  background-color: #f9f9f9;
  padding: 1em;
  border-radius: 4px;
  margin: 1em 0;
}
.sidebar {
  background-color: #f8f9fa;
}
'''