.post-header {
  text-align: center;
  padding: 2em 1em;
  border-bottom: 2px solid #ddd;
}

.welcome-title {
  font-size: 2em;
}

.intro {
  max-width: 800px;
  margin: 2em auto;
  padding: 1.5em;
  border-radius: 10px;
  background-color: rgba(255, 255, 255, 0.15);
  box-shadow: 0 3px 8px rgba(0,0,0,0.1);
}

.intro p {
  font-size: 1.1em;
}

.content {
  max-width: 800px;
  margin: 2em auto;
  padding: 0 1em;
}

.section-title {
  font-size: 1.5em;
  margin-top: 1em;
  border-left: 4px solid #0077cc;
  padding-left: 0.5em;
}

.problem-link a {
  color: #0077cc;
  text-decoration: none;
}

.problem-link a:hover {
  text-decoration: underline;
}

.author {
  margin-top: 100px;
  font-style: italic;
  color: #666;
}