:root {
  --azul: #1f3a5f;
  --azul-claro: #2f5a8f;
  --fondo: #f4f6f8;
  --texto: #1a1a1a;
  --borde: #d7dce1;
  --error: #b3261e;
  --exito: #1e6b3c;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  background: var(--fondo);
  color: var(--texto);
}

header.topbar {
  background: var(--azul);
  color: #fff;
  padding: 0.9rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
}

header.topbar a {
  color: #fff;
  text-decoration: none;
}

header.topbar .brand {
  font-weight: 700;
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.brand-logo {
  height: 40px;
  width: auto;
  max-width: 100%;
  object-fit: contain;
  display: block;
}

header.topbar nav {
  display: flex;
  align-items: center;
  gap: 1rem;
  font-size: 0.95rem;
}

header.topbar form { margin: 0; }

header.topbar button.btn-cerrar-sesion {
  background: var(--error);
  border: none;
  color: #fff;
  cursor: pointer;
  font-size: 0.85rem;
  padding: 0.4rem 0.8rem;
  border-radius: 6px;
  line-height: 1;
}

header.topbar button.btn-cerrar-sesion:hover {
  background: #8f1e18;
}

main {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.5rem 1.25rem 3rem;
}

.auth-card {
  max-width: 420px;
  margin: 3rem auto;
  background: #fff;
  border: 1px solid var(--borde);
  border-radius: 10px;
  padding: 2rem;
}

.auth-card h1 {
  font-size: 1.4rem;
  margin-top: 0;
  color: var(--azul);
}

label {
  display: block;
  font-weight: 600;
  margin: 0.9rem 0 0.3rem;
  font-size: 0.92rem;
}

input[type="text"],
input[type="email"],
input[type="password"],
select,
textarea {
  width: 100%;
  padding: 0.6rem 0.7rem;
  border: 1px solid var(--borde);
  border-radius: 6px;
  font-size: 1rem;
  font-family: inherit;
}

textarea { resize: vertical; }

button, .btn {
  display: inline-block;
  background: var(--azul);
  color: #fff;
  border: none;
  padding: 0.65rem 1.1rem;
  border-radius: 6px;
  font-size: 1rem;
  cursor: pointer;
  text-decoration: none;
  margin-top: 1rem;
}

button:hover, .btn:hover { background: var(--azul-claro); }

.btn-secundario {
  background: #fff;
  color: var(--azul);
  border: 1px solid var(--azul);
}

.btn-peligro {
  background: var(--error);
}

.mensaje-error {
  background: #fbe9e7;
  color: var(--error);
  border: 1px solid var(--error);
  border-radius: 6px;
  padding: 0.7rem 0.9rem;
  margin-top: 1rem;
  font-size: 0.92rem;
}

.mensaje-exito {
  background: #e6f4ea;
  color: var(--exito);
  border: 1px solid var(--exito);
  border-radius: 6px;
  padding: 0.7rem 0.9rem;
  margin-top: 1rem;
  font-size: 0.92rem;
}

.auth-links {
  margin-top: 1.2rem;
  font-size: 0.9rem;
}

.filtros {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  align-items: end;
  background: #fff;
  border: 1px solid var(--borde);
  border-radius: 8px;
  padding: 1rem;
  margin-bottom: 1.5rem;
}

.filtros .campo { flex: 1; min-width: 160px; }
.filtros label { margin-top: 0; }
.filtros button { margin-top: 0; }

.grid-libros {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 1.25rem;
}

.tarjeta-libro {
  background: #fff;
  border: 1px solid var(--borde);
  border-radius: 8px;
  overflow: hidden;
  text-decoration: none;
  color: var(--texto);
  display: flex;
  flex-direction: column;
  transition: box-shadow 0.15s;
}

.tarjeta-libro:hover { box-shadow: 0 4px 14px rgba(0,0,0,0.12); }

.tarjeta-libro img {
  width: 100%;
  aspect-ratio: 2 / 3;
  object-fit: cover;
  background: #eee;
}

.tarjeta-libro .info { padding: 0.6rem 0.7rem; }
.tarjeta-libro .titulo { font-weight: 600; font-size: 0.95rem; margin: 0 0 0.2rem; }
.tarjeta-libro .autor { font-size: 0.85rem; color: #555; margin: 0; }

.sin-resultados {
  text-align: center;
  color: #666;
  padding: 3rem 1rem;
}

.detalle-libro {
  display: flex;
  gap: 2rem;
  flex-wrap: wrap;
  background: #fff;
  border: 1px solid var(--borde);
  border-radius: 8px;
  padding: 1.5rem;
}

.detalle-libro img {
  width: 220px;
  aspect-ratio: 2/3;
  object-fit: cover;
  border-radius: 6px;
  background: #eee;
}

.detalle-libro .categorias {
  display: flex;
  gap: 0.4rem;
  flex-wrap: wrap;
  margin: 0.6rem 0 1rem;
}

.descripcion-libro {
  line-height: 1.5;
  color: #333;
  margin: 0 0 1rem;
}

.etiqueta {
  background: var(--fondo);
  border: 1px solid var(--borde);
  border-radius: 999px;
  padding: 0.2rem 0.7rem;
  font-size: 0.82rem;
  color: #444;
}

table.tabla-admin {
  width: 100%;
  border-collapse: collapse;
  background: #fff;
  border: 1px solid var(--borde);
  border-radius: 8px;
  overflow: hidden;
}

table.tabla-admin th, table.tabla-admin td {
  text-align: left;
  padding: 0.6rem 0.8rem;
  border-bottom: 1px solid var(--borde);
  font-size: 0.92rem;
}

table.tabla-admin th { background: var(--fondo); }

.acciones-fila { display: flex; gap: 0.6rem; }
.acciones-fila form { margin: 0; }
.acciones-fila button, .acciones-fila a.btn { margin-top: 0; padding: 0.35rem 0.7rem; font-size: 0.85rem; }

.checkbox-categorias {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 0.4rem;
  border: 1px solid var(--borde);
  border-radius: 6px;
  padding: 0.8rem;
  margin-top: 0.3rem;
}

.checkbox-categorias label {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-weight: 400;
  margin: 0;
}

.checkbox-categorias input { width: auto; }

.ayuda { font-size: 0.85rem; color: #666; margin-top: 0.2rem; }

.pagina-error {
  text-align: center;
  padding: 4rem 1rem;
}

.miniatura-actual {
  width: 90px;
  border-radius: 4px;
  margin-top: 0.4rem;
}

.fila-editar-categoria {
  display: flex;
  gap: 0.5rem;
  align-items: center;
  margin: 0;
}

.fila-editar-categoria input { flex: 1; margin: 0; }
.fila-editar-categoria button { margin-top: 0; padding: 0.4rem 0.9rem; font-size: 0.9rem; }

.barra-admin {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.2rem;
  flex-wrap: wrap;
  gap: 0.6rem;
}