/* ============================================================
   BIBLIOTECA DEL TUBERO - Estilos Principales
   Estilo: Futurista / Glass Morphism / Dark
   ============================================================ */

/* ---- Variables CSS ---- */
:root {
  /* Colores base */
  --clr-bg:           #080c14;
  --clr-bg-2:         #0d1422;
  --clr-surface:      rgba(255,255,255,0.04);
  --clr-surface-hover:rgba(255,255,255,0.07);
  --clr-border:       rgba(255,255,255,0.08);
  --clr-border-glow:  rgba(0,200,255,0.35);

  /* Colores de acento */
  --clr-primary:      #00c8ff;
  --clr-primary-dim:  rgba(0,200,255,0.15);
  --clr-primary-glow: rgba(0,200,255,0.4);
  --clr-secondary:    #7c3aed;
  --clr-accent:       #06ffa5;
  --clr-accent-dim:   rgba(6,255,165,0.12);
  --clr-danger:       #ff4757;
  --clr-warn:         #ffa726;

  /* Tipografía */
  --font-body:        'Inter', system-ui, -apple-system, sans-serif;
  --font-display:     'Space Grotesk', 'Inter', sans-serif;

  /* Tamaños */
  --radius-sm:        6px;
  --radius-md:        12px;
  --radius-lg:        18px;
  --radius-xl:        24px;

  /* Sombras */
  --shadow-sm:        0 2px 8px rgba(0,0,0,0.4);
  --shadow-md:        0 4px 24px rgba(0,0,0,0.5);
  --shadow-glow:      0 0 24px rgba(0,200,255,0.25);
  --shadow-card:      0 8px 32px rgba(0,0,0,0.6), 0 1px 0 rgba(255,255,255,0.06) inset;

  /* Transiciones */
  --transition-fast:  150ms ease;
  --transition-med:   250ms ease;
  --transition-slow:  400ms ease;

  /* Layout */
  --header-h:         70px;
  --filters-h:        64px;
  --sidebar-w:        280px;
}

/* ============================================================
   RESET + BASE
============================================================ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  background-color: var(--clr-bg);
  color: rgba(255,255,255,0.88);
  min-height: 100vh;
  line-height: 1.6;
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; border: none; background: none; }
input, select { font-family: inherit; }
img { display: block; max-width: 100%; }
svg { flex-shrink: 0; }

/* Scrollbar personalizado */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--clr-bg-2); }
::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.15); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: rgba(255,255,255,0.25); }

/* Focus visible */
:focus-visible {
  outline: 2px solid var(--clr-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* ============================================================
   CANVAS FONDO DECORATIVO
============================================================ */
#bg-canvas {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 0;
  opacity: 0.4;
}

/* ============================================================
   TIPOGRAFÍA
============================================================ */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.25;
}
code {
  font-family: 'Courier New', monospace;
  background: rgba(255,255,255,0.08);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.85em;
}

/* ============================================================
   HEADER
============================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  background: rgba(8, 12, 20, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--clr-border);
  box-shadow: 0 1px 30px rgba(0,0,0,0.5);
}

.header-inner {
  max-width: 1600px;
  margin: 0 auto;
  height: 100%;
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 20px;
}

/* Marca / Logo */
.header-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.brand-icon {
  width: 40px;
  height: 40px;
  color: var(--clr-primary);
  filter: drop-shadow(0 0 8px var(--clr-primary-glow));
}

.brand-title {
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 700;
  color: #fff;
  white-space: nowrap;
  letter-spacing: -0.02em;
}

.brand-subtitle {
  display: block;
  font-size: 0.7rem;
  color: rgba(255,255,255,0.4);
  font-weight: 400;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

/* Buscador del header */
.header-search {
  flex: 1;
  max-width: 500px;
}

.search-wrapper {
  position: relative;
  display: flex;
  align-items: center;
}

.search-icon {
  position: absolute;
  left: 14px;
  width: 18px;
  height: 18px;
  color: rgba(255,255,255,0.35);
  pointer-events: none;
  z-index: 1;
}

.search-input {
  width: 100%;
  height: 44px;
  padding: 0 40px 0 44px;
  background: rgba(255,255,255,0.06);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-xl);
  color: rgba(255,255,255,0.9);
  font-size: 0.95rem;
  transition: border-color var(--transition-med), background var(--transition-med), box-shadow var(--transition-med);
}

.search-input::placeholder { color: rgba(255,255,255,0.3); }
.search-input:focus {
  outline: none;
  border-color: var(--clr-primary);
  background: rgba(0,200,255,0.05);
  box-shadow: 0 0 0 3px var(--clr-primary-dim), var(--shadow-glow);
}
.search-input::-webkit-search-cancel-button { display: none; }

.search-clear {
  position: absolute;
  right: 10px;
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  color: rgba(255,255,255,0.4);
  transition: color var(--transition-fast), background var(--transition-fast);
}
.search-clear svg { width: 14px; height: 14px; }
.search-clear:hover { color: #fff; background: rgba(255,255,255,0.1); }

/* Acciones del header */
.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.btn-icon {
  position: relative;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  color: rgba(255,255,255,0.6);
  transition: color var(--transition-fast), background var(--transition-fast);
}
.btn-icon svg { width: 20px; height: 20px; }
.btn-icon:hover {
  color: #fff;
  background: rgba(255,255,255,0.08);
}

.btn-badge {
  position: absolute;
  top: 4px;
  right: 4px;
  min-width: 16px;
  height: 16px;
  padding: 0 4px;
  background: var(--clr-primary);
  color: #000;
  font-size: 10px;
  font-weight: 700;
  border-radius: 99px;
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
}

/* ============================================================
   FILTROS
============================================================ */
.filters-bar {
  position: sticky;
  top: var(--header-h);
  z-index: 90;
  background: rgba(8, 12, 20, 0.8);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--clr-border);
}

.filters-inner {
  max-width: 1600px;
  margin: 0 auto;
  padding: 12px 24px;
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.filter-group {
  display: flex;
  align-items: center;
  gap: 8px;
}

.filter-label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8rem;
  color: rgba(255,255,255,0.45);
  white-space: nowrap;
  font-weight: 500;
  letter-spacing: 0.03em;
  text-transform: uppercase;
}
.filter-label svg { width: 14px; height: 14px; }

.filter-select {
  height: 36px;
  padding: 0 32px 0 12px;
  background: rgba(255,255,255,0.06) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='rgba(255,255,255,0.4)' stroke-width='2' stroke-linecap='round'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E") no-repeat right 10px center;
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-sm);
  color: rgba(255,255,255,0.8);
  font-size: 0.88rem;
  -webkit-appearance: none;
  appearance: none;
  cursor: pointer;
  transition: border-color var(--transition-fast), background var(--transition-fast);
}
.filter-select:focus {
  outline: none;
  border-color: var(--clr-primary);
  background-color: rgba(0,200,255,0.06);
}
.filter-select option { background: #0d1422; color: #fff; }

/* Chips de filtros activos */
.active-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  align-items: center;
  flex: 1;
}

.filter-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  background: var(--clr-primary-dim);
  border: 1px solid rgba(0,200,255,0.3);
  border-radius: 99px;
  font-size: 0.78rem;
  color: var(--clr-primary);
  font-weight: 500;
}
.filter-chip button {
  width: 14px;
  height: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  color: var(--clr-primary);
  opacity: 0.7;
  transition: opacity var(--transition-fast);
}
.filter-chip button:hover { opacity: 1; }
.filter-chip button svg { width: 10px; height: 10px; }

.btn-reset-filters {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.82rem;
  color: rgba(255,255,255,0.5);
  transition: color var(--transition-fast), background var(--transition-fast);
}
.btn-reset-filters svg { width: 14px; height: 14px; }
.btn-reset-filters:hover { color: var(--clr-danger); background: rgba(255,71,87,0.1); }

.results-meta {
  max-width: 1600px;
  margin: 0 auto;
  padding: 4px 24px 10px;
}

.results-count {
  font-size: 0.8rem;
  color: rgba(255,255,255,0.35);
  font-weight: 500;
}

/* ============================================================
   MAIN CONTENT
============================================================ */
.main-content {
  position: relative;
  z-index: 1;
  max-width: 1600px;
  margin: 0 auto;
  padding: 32px 24px 80px;
  min-height: calc(100vh - var(--header-h) - var(--filters-h));
}

/* ============================================================
   ESTADOS (loading / error / empty)
============================================================ */
.state-panel {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
  min-height: 400px;
  text-align: center;
  padding: 48px 24px;
}
.state-panel[hidden] { display: none; }

.state-title {
  font-size: 1.3rem;
  color: rgba(255,255,255,0.8);
}
.state-text {
  font-size: 0.95rem;
  color: rgba(255,255,255,0.4);
  max-width: 400px;
  line-height: 1.6;
}

.state-icon {
  width: 72px;
  height: 72px;
  color: rgba(255,255,255,0.2);
}
.state-icon.error-icon { color: var(--clr-danger); opacity: 0.7; }

/* ---- Loader ring ---- */
.loader-ring {
  display: inline-block;
  position: relative;
  width: 60px;
  height: 60px;
}
.loader-ring div {
  box-sizing: border-box;
  display: block;
  position: absolute;
  width: 48px;
  height: 48px;
  margin: 6px;
  border: 3px solid transparent;
  border-top-color: var(--clr-primary);
  border-radius: 50%;
  animation: spin 1.2s cubic-bezier(0.5,0,0.5,1) infinite;
}
.loader-ring div:nth-child(1) { animation-delay: -0.45s; }
.loader-ring div:nth-child(2) { animation-delay: -0.3s; border-top-color: var(--clr-secondary); }
.loader-ring div:nth-child(3) { animation-delay: -0.15s; border-top-color: var(--clr-accent); }
.loader-ring div:nth-child(4) { animation-delay: 0s; }

@keyframes spin {
  0%   { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* ============================================================
   BOTONES
============================================================ */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  background: linear-gradient(135deg, var(--clr-primary), #0090cc);
  color: #000;
  font-weight: 600;
  font-size: 0.9rem;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), filter var(--transition-fast);
  position: relative;
  overflow: hidden;
  text-decoration: none;
}
.btn-primary svg { width: 18px; height: 18px; }
.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 24px rgba(0,200,255,0.4);
  filter: brightness(1.1);
}
.btn-primary:active { transform: translateY(0); }

/* Efecto ripple */
.btn-primary::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle, rgba(255,255,255,0.3) 0%, transparent 70%);
  opacity: 0;
  transition: opacity var(--transition-fast);
}
.btn-primary:active::after { opacity: 1; }

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  background: rgba(255,255,255,0.06);
  color: rgba(255,255,255,0.8);
  font-weight: 500;
  font-size: 0.9rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--clr-border);
  cursor: pointer;
  transition: background var(--transition-fast), border-color var(--transition-fast), color var(--transition-fast);
  text-decoration: none;
}
.btn-secondary svg { width: 18px; height: 18px; }
.btn-secondary:hover {
  background: rgba(255,255,255,0.1);
  border-color: rgba(255,255,255,0.2);
  color: #fff;
}

.btn-full { width: 100%; justify-content: center; }

/* Card button */
.btn-card {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  background: rgba(0,200,255,0.1);
  border: 1px solid rgba(0,200,255,0.25);
  border-radius: var(--radius-sm);
  color: var(--clr-primary);
  font-size: 0.83rem;
  font-weight: 500;
  transition: background var(--transition-fast), border-color var(--transition-fast), box-shadow var(--transition-fast);
}
.btn-card svg { width: 15px; height: 15px; }
.btn-card:hover {
  background: rgba(0,200,255,0.18);
  border-color: rgba(0,200,255,0.5);
  box-shadow: 0 0 12px rgba(0,200,255,0.2);
  color: #fff;
}

/* ============================================================
   GRID DE MANUALES
============================================================ */
.gallery-container[hidden] { display: none; }

.manuals-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}

/* Vista lista */
.manuals-grid.list-view {
  grid-template-columns: 1fr;
  gap: 12px;
}

/* ============================================================
   CARDS DE MANUAL
============================================================ */
.manual-card {
  display: flex;
  flex-direction: column;
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-card);
  transition:
    transform var(--transition-med),
    border-color var(--transition-med),
    box-shadow var(--transition-med);
  cursor: default;
  position: relative;
}

.manual-card:hover {
  transform: translateY(-4px) scale(1.01);
  border-color: var(--clr-border-glow);
  box-shadow:
    0 16px 48px rgba(0,0,0,0.7),
    0 0 0 1px rgba(0,200,255,0.2),
    var(--shadow-glow);
}

/* Portada */
.card-cover-wrapper {
  position: relative;
  width: 100%;
  aspect-ratio: 4/5;
  overflow: hidden;
  background: var(--clr-bg-2);
  flex-shrink: 0;
}

.card-cover-placeholder {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 32px;
}
.card-cover-placeholder svg {
  width: 100%;
  max-width: 120px;
  height: auto;
  color: var(--clr-primary);
}

.card-cover-img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow), opacity var(--transition-med);
  opacity: 0;
}
.card-cover-img.loaded { opacity: 1; }
.manual-card:hover .card-cover-img { transform: scale(1.04); }

/* Overlay degradado */
.card-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    to bottom,
    transparent 40%,
    rgba(8,12,20,0.6) 70%,
    rgba(8,12,20,0.95) 100%
  );
}

/* Botón de favorito */
.card-fav-btn {
  position: absolute;
  top: 10px;
  right: 10px;
  width: 34px;
  height: 34px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: rgba(8,12,20,0.7);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255,255,255,0.1);
  color: rgba(255,255,255,0.5);
  transition: color var(--transition-fast), background var(--transition-fast), border-color var(--transition-fast);
  z-index: 2;
}
.card-fav-btn svg { width: 16px; height: 16px; }
.card-fav-btn:hover { color: var(--clr-danger); border-color: rgba(255,71,87,0.4); }
.card-fav-btn.active { color: var(--clr-danger); }
.card-fav-btn.active .icon-heart-outline { display: none; }
.card-fav-btn.active .icon-heart-filled { display: block !important; }

/* Cuerpo de la card */
.card-body {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 16px;
  flex: 1;
}

.card-meta-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.card-category {
  display: inline-flex;
  align-items: center;
  padding: 3px 10px;
  border-radius: 99px;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  white-space: nowrap;
}

.card-version {
  font-size: 0.72rem;
  color: rgba(255,255,255,0.3);
  font-weight: 500;
}

.card-title {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  color: rgba(255,255,255,0.92);
  line-height: 1.3;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-description {
  font-size: 0.83rem;
  color: rgba(255,255,255,0.45);
  line-height: 1.55;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  flex: 1;
}

.card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
}

.card-tag {
  padding: 2px 8px;
  border-radius: 99px;
  font-size: 0.7rem;
  color: rgba(255,255,255,0.5);
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.07);
}

.card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  margin-top: auto;
  padding-top: 4px;
  border-top: 1px solid rgba(255,255,255,0.05);
}

.card-date {
  font-size: 0.75rem;
  color: rgba(255,255,255,0.3);
}

/* Colores de categorías (auto-generados por clase) */
.cat-trazado        { background: rgba(0,200,255,0.1);   color: var(--clr-primary);  border: 1px solid rgba(0,200,255,0.25); }
.cat-caldereria     { background: rgba(124,58,237,0.12); color: #a78bfa;              border: 1px solid rgba(124,58,237,0.3); }
.cat-soldadura      { background: rgba(255,167,38,0.1);  color: #ffa726;              border: 1px solid rgba(255,167,38,0.25); }
.cat-plomeria       { background: rgba(6,255,165,0.08);  color: var(--clr-accent);   border: 1px solid rgba(6,255,165,0.2); }
.cat-montaje        { background: rgba(79,195,247,0.1);  color: #4fc3f7;              border: 1px solid rgba(79,195,247,0.25); }
.cat-referencia     { background: rgba(255,255,255,0.05);color: rgba(255,255,255,0.6);border: 1px solid rgba(255,255,255,0.1); }
.cat-estructuras    { background: rgba(255,82,82,0.1);   color: #ff5252;              border: 1px solid rgba(255,82,82,0.25); }
.cat-planos-trazado { background: rgba(0,200,255,0.1);   color: var(--clr-primary);  border: 1px solid rgba(0,200,255,0.25); }
.cat-default        { background: rgba(255,255,255,0.05);color: rgba(255,255,255,0.5);border: 1px solid rgba(255,255,255,0.08); }

/* ============================================================
   VISTA LISTA (alternativa)
============================================================ */
.list-view .manual-card {
  flex-direction: row;
  max-height: 140px;
}

.list-view .card-cover-wrapper {
  width: 100px;
  aspect-ratio: unset;
  height: 100%;
  flex-shrink: 0;
}

.list-view .card-body {
  gap: 6px;
  padding: 14px 16px;
}

.list-view .card-description { -webkit-line-clamp: 2; }
.list-view .card-tags { display: none; }

/* ============================================================
   PANELES LATERALES (favoritos / historial)
============================================================ */
.side-panel {
  position: fixed;
  right: 0;
  top: var(--header-h);
  bottom: 0;
  width: var(--sidebar-w);
  background: rgba(13, 20, 34, 0.96);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-left: 1px solid var(--clr-border);
  z-index: 150;
  display: flex;
  flex-direction: column;
  transform: translateX(100%);
  transition: transform var(--transition-med);
  box-shadow: -8px 0 32px rgba(0,0,0,0.5);
}
.side-panel:not([hidden]) { transform: translateX(0); }
.side-panel[hidden] { display: flex; }

.side-panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  border-bottom: 1px solid var(--clr-border);
}
.side-panel-header h2 {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 1rem;
  font-weight: 600;
}
.side-panel-header h2 svg { width: 18px; height: 18px; color: var(--clr-primary); }

.side-panel-list {
  flex: 1;
  overflow-y: auto;
  padding: 12px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.side-panel-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px;
  border-radius: var(--radius-md);
  border: 1px solid var(--clr-border);
  background: var(--clr-surface);
  cursor: pointer;
  transition: background var(--transition-fast), border-color var(--transition-fast);
  text-decoration: none;
  color: inherit;
}
.side-panel-item:hover {
  background: var(--clr-surface-hover);
  border-color: rgba(0,200,255,0.2);
}

.side-panel-item-thumb {
  width: 40px;
  height: 52px;
  border-radius: 4px;
  background: var(--clr-bg-2);
  overflow: hidden;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}
.side-panel-item-thumb img { width: 100%; height: 100%; object-fit: cover; }
.side-panel-item-thumb svg { width: 20px; height: 20px; color: rgba(255,255,255,0.2); }

.side-panel-item-info { flex: 1; min-width: 0; }
.side-panel-item-title {
  font-size: 0.83rem;
  font-weight: 500;
  line-height: 1.3;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  color: rgba(255,255,255,0.85);
}
.side-panel-item-cat {
  font-size: 0.72rem;
  color: rgba(255,255,255,0.4);
  margin-top: 2px;
}

.side-panel-empty {
  text-align: center;
  padding: 40px 20px;
  color: rgba(255,255,255,0.3);
  font-size: 0.88rem;
  line-height: 1.6;
}

/* ============================================================
   FOOTER
============================================================ */
.site-footer {
  position: relative;
  z-index: 1;
  padding: 20px 24px;
  border-top: 1px solid var(--clr-border);
  background: rgba(8,12,20,0.7);
}
.footer-inner {
  max-width: 1600px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  font-size: 0.8rem;
  color: rgba(255,255,255,0.3);
}
.footer-brand { font-weight: 600; color: rgba(255,255,255,0.5); }
.footer-sep { opacity: 0.4; }

/* ============================================================
   ANIMACIONES DE ENTRADA DE CARDS
============================================================ */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: translateY(0); }
}

.manual-card {
  animation: fadeInUp 0.4s ease both;
}

/* Retrasar animación por índice */
.manual-card:nth-child(1)  { animation-delay: 0.02s; }
.manual-card:nth-child(2)  { animation-delay: 0.04s; }
.manual-card:nth-child(3)  { animation-delay: 0.06s; }
.manual-card:nth-child(4)  { animation-delay: 0.08s; }
.manual-card:nth-child(5)  { animation-delay: 0.10s; }
.manual-card:nth-child(6)  { animation-delay: 0.12s; }
.manual-card:nth-child(7)  { animation-delay: 0.14s; }
.manual-card:nth-child(8)  { animation-delay: 0.16s; }
.manual-card:nth-child(9)  { animation-delay: 0.18s; }
.manual-card:nth-child(10) { animation-delay: 0.20s; }
.manual-card:nth-child(11) { animation-delay: 0.22s; }
.manual-card:nth-child(12) { animation-delay: 0.24s; }

/* ============================================================
   RESPONSIVE
============================================================ */
@media (max-width: 1024px) {
  .manuals-grid {
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  }
}

@media (max-width: 768px) {
  :root { --header-h: 60px; }

  .header-inner { padding: 0 16px; gap: 12px; }
  .brand-subtitle { display: none; }
  .brand-title { font-size: 1rem; }
  .brand-icon { width: 32px; height: 32px; }

  .header-search { max-width: none; }

  .filters-inner { padding: 10px 16px; gap: 8px; }
  .filter-label { display: none; }

  .main-content { padding: 20px 16px 60px; }

  .manuals-grid {
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: 14px;
  }

  .card-body { padding: 12px; gap: 8px; }
  .card-title { font-size: 0.88rem; }
  .card-description { display: none; }

  .side-panel { width: 100%; }
}

@media (max-width: 480px) {
  .manuals-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
  }

  .header-actions .btn-icon:not(:last-child) { display: none; }
}

/* ============================================================
   GRADIENTE DE FONDO (fallback sin canvas)
============================================================ */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 20% 20%, rgba(0,200,255,0.06) 0%, transparent 60%),
    radial-gradient(ellipse 60% 40% at 80% 80%, rgba(124,58,237,0.06) 0%, transparent 60%),
    radial-gradient(ellipse 50% 60% at 50% 50%, rgba(6,255,165,0.03) 0%, transparent 70%);
  pointer-events: none;
  z-index: 0;
}