/* Variables de color */
:root {
  --bg: #14223d;
  --bg-2: #1b263b;
  --text: #e0e0e0;
  --accent: #3a86ff;
  --accent-2: #00c6ff;
  --radius: 12px;
}

/* Reset básico */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  padding: 20px;
}

/* Encabezado */
header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 30px;
}

h1 {
  font-size: 1.8rem;
}

/* Lista de PDFs en grid */
.pdf-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}

/* Tarjetas */
.card {
  background: linear-gradient(180deg, rgba(255,255,255,0.015), rgba(255,255,255,0.01));
  border-radius: var(--radius);
  padding: 18px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 12px;
  box-shadow: 0 6px 20px rgba(2,6,23,0.5);
  transition: transform 240ms cubic-bezier(.2,.9,.2,1), box-shadow 240ms;
  border: 1px solid rgba(255,255,255,0.03);
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 30px rgba(2,6,23,0.6);
}

.card-meta {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  width: 100%;
}

.icon {
  width: 28px;
  height: 28px;
  color: var(--accent);
  flex-shrink: 0;
}

.card-title {
  margin: 0;
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.3;
  white-space: normal;
  overflow: visible;
  text-overflow: unset;
}

.card-desc {
  font-size: 0.85rem;
  color: #a8a8a8;
}

.card-actions {
  width: 100%;
  display: flex;
  justify-content: flex-end;
}

/* Botón de descarga */
.btn {
  display: inline-block;
  padding: 6px 10px;
  background: linear-gradient(90deg, var(--accent) 0%, var(--accent-2) 100%);
  color: #072033;
  font-weight: 600;
  text-decoration: none;
  border-radius: 8px;
  box-shadow: 0 4px 12px rgba(6,25,40,0.25);
  transition: transform 160ms, box-shadow 160ms, opacity 160ms;
  font-size: 0.8rem;
  white-space: nowrap;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 20px rgba(6,25,40,0.28);
  opacity: 0.98;
}

/* Dropdown menu */
.dropdown {
  position: relative;
  display: inline-block;
}

.dropbtn {
  background: linear-gradient(90deg, var(--accent) 0%, var(--accent-2) 100%);
  color: #072033;
  padding: 8px 14px;
  font-size: 0.9rem;
  font-weight: 600;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(6,25,40,0.25);
  transition: transform 160ms, box-shadow 160ms;
}

.dropbtn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 18px rgba(6,25,40,0.3);
}

.dropdown-content {
  display: none;
  position: absolute;
  right: 0;
  background-color: var(--bg-2);
  min-width: 160px;
  border-radius: 10px;
  box-shadow: 0 6px 20px rgba(2,6,23,0.5);
  z-index: 1;
  overflow: hidden;
}

.dropdown-content a {
  color: var(--text);
  padding: 10px 14px;
  text-decoration: none;
  display: block;
  font-size: 0.9rem;
  transition: background 200ms;
}

.dropdown-content a:hover {
  background-color: rgba(255,255,255,0.08);
}

.dropdown:hover .dropdown-content {
  display: block;
}

.page-center {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
}

.message-card {
  max-width: 460px;   /* ancho máximo del cuadro */
  width: 90%;         /* ocupa hasta 90% en pantallas pequeñas */
  padding: 30px 25px; /* espacio interno */
  text-align: center;
}

.message-card .card-actions {
  display: flex;
  justify-content: center;  /* centra horizontalmente */
  margin-top: 20px;         /* separa el botón del texto */
}