body {
  font-family: 'Segoe UI', Tahoma, Arial, sans-serif;
  background: #121212;
  color: #eee;
  margin: 0;
  padding: 0;
  line-height: 1.6;
}

header {
  background: #1f1f1f;
  color: #0f62fe;
  padding: 15px;
  text-align: center;
  box-shadow: 0 2px 5px rgba(0,0,0,0.5);
}

h1 { margin: 0; }

.hw-list {
  list-style: none;
  padding: 20px;
  max-width: 600px;
  margin: auto;
}

.hw-list li {
  margin: 15px 0;
}

.hw-list a {
  text-decoration: none;
  padding: 15px;
  display: block;
  background: #1f1f1f;
  border-radius: 8px;
  box-shadow: 0 2px 5px rgba(0,0,0,0.5);
  color: #0f62fe;
  font-weight: bold;
  transition: 0.3s;
}

.hw-list a:hover {
  background: #0f62fe;
  color: #fff;
}

.example {
  display: none;
  background: #1f1f1f;
  padding: 15px;
  margin-top: 15px;
  border-radius: 8px;
  color: #0f62fe;
  box-shadow: inset 0 0 5px rgba(0,0,0,0.6);
}

.back-link {
  display: inline-block;
  margin-top: 10px;
  color: #0f62fe;
  text-decoration: none;
}