Create a cascading stylesheet for a website.
Here is an example of a cascading stylesheet for a website:

```
body {
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  margin: 0;
  padding: 0;
}

header, nav, main, footer {
  max-width: 1200px;
  margin: 0 auto;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px;
  background-color: #333;
  color: #fff;
}

header h1 {
  margin: 0;
  font-size: 2.5em;
}

nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
}

nav ul li {
  margin: 0 10px;
}

nav ul li a {
  color: #fff;
  text-decoration: none;
  font-size: 1.2em;
}

main {
  padding: 20px;
}

main h2 {
  font-size: 2em;
  margin-top: 0;
}

main p {
  font-size: 1.2em;
  line-height: 1.5;
}

footer {
  padding: 20px;
  background-color: #333;
  color: #fff;
}

footer p {
  margin: 0;
  text-align: center;
}
```

This stylesheet sets the font family for the entire website, centers the content within a maximum width of 1200px, and adds styling for the header, navigation, main content, and footer sections. Background colors, text colors, font sizes, and margins and paddings are all defined for different elements. Of course, the specific styles used can be customized to fit the needs and design of the website in question.
Below is an instruction that describes a task, write a response that appropriately completes the request.

### Instruction:
Create a cascading stylesheet for a website.

### Response:
Here is an example of a cascading stylesheet for a website:

```
body {
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  margin: 0;
  padding: 0;
}

header, nav, main, footer {
  max-width: 1200px;
  margin: 0 auto;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px;
  background-color: #333;
  color: #fff;
}

header h1 {
  margin: 0;
  font-size: 2.5em;
}

nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
}

nav ul li {
  margin: 0 10px;
}

nav ul li a {
  color: #fff;
  text-decoration: none;
  font-size: 1.2em;
}

main {
  padding: 20px;
}

main h2 {
  font-size: 2em;
  margin-top: 0;
}

main p {
  font-size: 1.2em;
  line-height: 1.5;
}

footer {
  padding: 20px;
  background-color: #333;
  color: #fff;
}

footer p {
  margin: 0;
  text-align: center;
}
```

This stylesheet sets the font family for the entire website, centers the content within a maximum width of 1200px, and adds styling for the header, navigation, main content, and footer sections. Background colors, text colors, font sizes, and margins and paddings are all defined for different elements. Of course, the specific styles used can be customized to fit the needs and design of the website in question.