* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Segoe UI', sans-serif;
}

body {
  background: #0e1a2b;
  color: #fff;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.navbar {
  position: fixed;
  top: 0;
  width: 100%;
  background: #08111f;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px 30px;
  z-index: 1000;
  box-shadow: 0 2px 10px rgba(0,0,0,0.5);
}

.logo {
  font-size: 24px;
  font-weight: bold;
  color: #3fa9f5;
}

.nav-links {
  list-style: none;
  display: flex;
  gap: 20px;
}

.nav-links li a {
  text-decoration: none;
  color: #ccc;
  transition: color 0.3s ease;
}

.nav-links li a:hover {
  color: #3fa9f5;
}

.hero {
  flex: 1;
  padding-top: 100px;
  display: flex;
  justify-content: center;
  align-items: center;
  text-align: center;
  background: linear-gradient(to bottom right, #102540, #0c1b2a);
  padding: 60px 20px;
}

.hero-text h1 {
  font-size: 2.8rem;
  margin-bottom: 20px;
  color: #fff;
}

.hero-text p {
  font-size: 1.1rem;
  color: #ccc;
  margin-bottom: 30px;
}

.buttons {
  display: flex;
  flex-direction: column;
  gap: 15px;
  max-width: 300px;
  margin: 0 auto;
}

.btn {
  text-decoration: none;
  padding: 12px;
  border-radius: 8px;
  font-weight: bold;
  transition: background 0.3s ease;
  text-align: center;
}

.btn.alumno {
  background: #3fa9f5;
  color: #fff;
}

.btn.docente {
  background: #5cd65c;
  color: #fff;
}

.btn.admin {
  background: #f59e3f;
  color: #fff;
}

.btn:hover {
  filter: brightness(1.2);
}

footer {
  text-align: center;
  padding: 15px;
  background: #08111f;
  font-size: 0.9rem;
  color: #777;
  margin-top: auto;
}