html, body {
  height: 100%;
  margin: 0;
  padding: 0;
}
body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: #f3f3f3;
  font-family: Arial, sans-serif;
}
.main-wrapper {
  flex: 1 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
}
.header {
  display: flex;
  flex-direction: column;
  align-items: center;
  margin-top: 28px;
}
.logo {
  width: 100px;
  height: auto;
  margin-bottom: 10px;
}
h1, h2 {
  color: #226;
  margin: 0;
}
h1.center {
  text-align: center;
  width: 100%;
}
.espacio-titulo {
  height: 35px;
}
.links-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  justify-content: center;
  width: 100%;
}
.link-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  background: #fff;
  padding: 15px;
  border-radius: 10px;
  text-decoration: none;
  color: #222;
  box-shadow: 0 2px 8px #ccc;
  width: 160px;
  transition: box-shadow 0.2s;
}
.link-btn:hover {
  box-shadow: 0 4px 16px #aaa;
}
.link-btn img {
  width: 100px;
  height: 100px;
  object-fit: cover;
  margin-bottom: 10px;
  border-radius: 8px;
}
.abm-btn {
  background: #226;
  color: #fff;
  padding: 8px 22px;
  border-radius: 5px;
  text-decoration: none;
  margin: 30px 0 0 0;
  display: inline-block;
}
form input[type=text], form input[type=password] {
  margin: 6px 0;
  padding: 6px;
  width: 220px;
}
form button {
  margin-top: 8px;
  padding: 7px 16px;
}
.error {
  color: red;
  margin-top: 10px;
}
table {
  background: #fff;
}
table td, table th {
  padding: 7px 10px;
}
footer {
  flex-shrink: 0;
  text-align: center;
  color: #888;
  padding: 18px 0 10px 0;
  background: none;
  width: 100%;
  margin-top: auto;
}
.footer-link {
  color: #226;
  text-decoration: none;
  font-weight: bold;
}
.footer-link:hover {
  text-decoration: underline;
}