/* Base layout */
body {
  font-family: sans-serif;
  max-width: 600px;
  margin: 2em auto;
  text-align: center;
  background-color: #f9f9f9;
  color: #111;
}

h1, h2, h3 {
  margin-bottom: 1em;
}

ul {
  list-style: none;
  padding: 0;
}

ul li {
  margin: 0.5em 0;
}

/* Button base */
.button,
.button-main {
  padding: 0.6em 1.2em;
  font-size: 1em;
  background-color: #333;
  color: white;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  text-decoration: none;
  display: inline-block;
}

.button-main {
  font-size: 1.2em;
  margin-top: 1em;
}

/* Error box */
.error-box {
  color: #a94442;
  background-color: #f2dede;
  border: 1px solid #ebccd1;
  border-radius: 4px;
  padding: 1.5em;
  margin-bottom: 2em;
  display: inline-block;
}

/* Success banner */
#success-message {
  display: none;
  padding: 1em;
  background: #dff0d8;
  color: #3c763d;
  border: 1px solid #d6e9c6;
  border-radius: 4px;
  margin-bottom: 1em;
  text-align: center;
}

/* File list area */
.instance-list {
  margin-top: 3em;
  text-align: left;
}

.instance-item {
  margin-bottom: 0.5em;
}

/* Forms */
form {
  margin-top: 1.5em;
}

input[type="password"],
input[type="text"],
input[type="file"],
input[type="number"] {
  padding: 0.5em;
  width: 100%;
  max-width: 400px;
  margin: 0.5em 0;
  border: 1px solid #ccc;
  border-radius: 4px;
}

label {
  display: block;
  margin-bottom: 0.3em;
  font-weight: bold;
}

/* Back to Main */
.back-button {
  margin-top: 2em;
}
.centered-page {
  font-family: sans-serif;
  max-width: 600px;
  margin: 2em auto;
  text-align: center;
}

input[type="text"],
input[type="password"],
input[type="number"],
input[type="file"] {
  padding: 0.5em;
  margin: 0.5em 0;
  width: 100%;
  max-width: 400px;
  border: 1px solid #ccc;
  border-radius: 4px;
}