```css id="m4"
body {
  font-family: Arial, sans-serif;
  margin: 0;
  background: #f4f6f8;
  color: #111;
}

.hero {
  background: #111827;
  color: white;
  text-align: center;
  padding: 40px 20px;
}

.container {
  max-width: 900px;
  margin: auto;
  padding: 20px;
}

.tool,
.content {
  background: white;
  padding: 20px;
  margin-top: 20px;
  border-radius: 10px;
}

textarea,
input {
  width: 100%;
  padding: 12px;
  margin: 10px 0;
  font-size: 16px;
}

button {
  background: #2563eb;
  color: white;
  border: none;
  padding: 10px 16px;
  cursor: pointer;
  border-radius: 6px;
}

button:hover {
  background: #1e40af;
}

pre {
  background: #eee;
  padding: 10px;
  overflow-x: auto;
  border-radius: 6px;
}

.ad-box {
  margin-top: 20px;
  padding: 30px;
  border: 2px dashed #ccc;
  text-align: center;
  background: #fffbea;
}

.tool-list a {
  display: block;
  padding: 12px;
  margin: 10px 0;
  background: white;
  border-radius: 8px;
  text-decoration: none;
  color: #111;
}

.tool-list a:hover {
  background: #e5e7eb;
}
```