Bootstrap example (Guestbook)
by netperformance
HTML
<!doctype html>
<html lang="en">
<head>
<!-- Required meta tags -->
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<!-- Bootstrap CSS -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
<!--Custom CSS -->
<link rel="stylesheet" href="assets/css/style.css">
<title>Guestbook</title>
</head>
<body>
<!--Navbar -->
<nav class="navbar navbar-dark bg-dark">
<div class="container">
<a class="navbar-brand" href="#">Guestbook</a>
</div>
</nav>
<br/>
<div class="container">
<div class="row">
<!--left side -->
<div class="col-4">
<!--form-->
<div class="container border border-dark rounded bg-light">
<form> <!-- class="needs-validation" novalidate -->
<div class="form-group">
<label class="font-weight-bold">Name *</label>
<input type="text" class="form-control" id="name" placeholder="firstname lastname" minlength="3" maxlength="30" required>
<!--
<div class="valid-feedback">
Looks good!
</div>
<div class="invalid-feedback">
Doesn't look good!
</div>
-->
</div>
<div class="form-group">
<label class="font-weight-bold">E-mail address</label>
<input type="email" class="form-control" id="email" placeholder="your@domain.com">
</div>
<div class="form-group">
<label class="font-weight-bold">Message *</label>
<textarea class="form-control" id="message" rows="3" minlength="2" maxlength="500" required></textarea>
</div>
<button type="submit" class="btn btn-dark btn-sm">Save message</button><br/><br/>
</form>
</div>
<!--end form-->
</div>
<!-- right side...