/* Reset y tipografía base */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

/* Paleta y layout base */
:root {
  --azul: #1f3c88;
  --azul-oscuro: #162f6a;
  --gris: #f4f7fb;
  --texto: #222;
}

body {
  background-color: var(--gris);
  color: var(--texto);
  line-height: 1.6;
  display: flex;
  flex-direction: column;
  min-height: 100vh; /* footer al fondo */
}

/* Encabezado */
header {
  background-color: var(--azul);
  color: #fff;
  padding: 20px;
  text-align: center;
  border-bottom: 5px solid var(--azul-oscuro);
  animation: slideDown 1s ease-out;
}

header h1 {
  font-size: 2rem;
}

header p {
  font-size: 1rem;
  opacity: 0.95;
}

/* Contenido principal crece para empujar el footer */
main {
  flex: 1;
}

/* Página principal (home) */
.home-container {
  max-width: 700px;
  margin: 60px auto;
  text-align: center;
  padding: 0 16px;
}

.home-container h2 {
  margin-bottom: 20px;
  font-size: 1.6rem;
  color: var(--azul);
}

.home-buttons {
  display: flex;
  justify-content: center;
  gap: 20px;
  flex-wrap: wrap;
}

/* Botones principales */
.btn-large {
  display: inline-block;
  padding: 15px 30px;
  background-color: var(--azul);
  color: #fff;
  text-decoration: none;
  font-size: 1.1rem;
  border-radius: 10px;
  transition: background-color 0.3s, transform 0.2s;
}

.btn-large:hover {
  background-color: var(--azul-oscuro);
  transform: scale(1.08);
}

/* Páginas de cuatrimestre */
.cuatrimestre {
  padding: 30px 16px;
  max-width: 900px;
  margin: auto;
}

.cuatrimestre h2 {
  font-size: 1.8rem;
  color: var(--azul);
  margin-bottom: 20px;
}

/* Grid de evidencias */
.evidencias {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}

/* Tarjeta */
.card {
  background: #fff;
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.1);
  text-align: center;
  transition: transform 0.3s ease;
}

.card:hover {
  transform: scale(1.07);
}

.card h3 {
  color: var(--azul);
  margin-bottom: 10px;
}

.card p {
  font-size: 0.95rem;
  color: #666;
}

/* Botón estándar */
.btn {
  display: inline-block;
  padding: 10px 20px;
  background-color: var(--azul);
  color: #fff;
  text-decoration: none;
  border-radius: 6px;
  font-weight: bold;
  transition: background-color 0.3s;
}

.btn:hover {
  background-color: var(--azul-oscuro);
}

/* Botón de regreso */
.btn-back {
  display: inline-block;
  margin-top: 30px;
  padding: 10px 25px;
  background-color: var(--azul-oscuro);
  color: #fff;
  border-radius: 8px;
  text-decoration: none;
  transition: background-color 0.3s;
}

.btn-back:hover {
  background-color: #0f2e66;
}

/* Footer fijo al final */
footer {
  background-color: var(--azul);
  color: #fff;
  text-align: center;
  padding: 15px;
  font-size: 0.9rem;
}

/* Animaciones */
@keyframes slideDown {
  from { transform: translateY(-50px); opacity: 0; }
  to   { transform: translateY(0); opacity: 1; }
}

.fade-in { animation: fadeIn 1.2s ease-in-out; }
@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

.zoom-in { animation: zoomIn 1s ease; }
@keyframes zoomIn {
  from { transform: scale(0.8); opacity: 0; }
  to   { transform: scale(1); opacity: 1; }
}

.bounce { animation: bounce 1.5s infinite; }
@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(-6px); }
}

.pulse { animation: pulse 1.8s infinite; }
/* #1f3c88 -> rgb(31, 60, 136) */
@keyframes pulse {
  0%   { box-shadow: 0 0 0 0 rgba(31,60,136,0.7); }
  70%  { box-shadow: 0 0 0 12px rgba(31,60,136,0); }
  100% { box-shadow: 0 0 0 0 rgba(31,60,136,0); }
}