/* ═══════════════════════════════════════════════════════
   ATENEO.AR — Design System
   ═══════════════════════════════════════════════════════ */
:root {
  --bg: #0f0e17;
  --bg-card: #1a1929;
  --bg-card-hover: #232240;
  --bg-surface: #16152a;
  --text: #f0eff4;
  --text-muted: #9490b3;
  --accent: #7f5af0;
  --accent-glow: #a78bfa;
  --accent2: #2cb67d;
  --accent3: #e16162;
  --gradient-hero: linear-gradient(135deg, #0f0e17 0%, #1e1b4b 40%, #312e81 100%);
  --gradient-accent: linear-gradient(135deg, #7f5af0, #a78bfa);
  --gradient-card: linear-gradient(145deg, rgba(127,90,240,0.08), rgba(44,182,125,0.05));
  --shadow-lg: 0 20px 60px rgba(0,0,0,0.5);
  --shadow-card: 0 4px 24px rgba(0,0,0,0.3);
  --shadow-glow: 0 0 30px rgba(127,90,240,0.15);
  --radius: 16px;
  --radius-sm: 10px;
  --radius-xs: 6px;
  --font: 'Inter', system-ui, -apple-system, sans-serif;
  --font-display: 'Playfair Display', Georgia, serif;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

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

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
.hidden { display: none !important; }

/* ═══ HEADER ═══════════════════════════════════════════ */
#main-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 16px 24px;
  background: rgba(15,14,23,0.85);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid rgba(127,90,240,0.1);
  transition: var(--transition);
}

.header-inner { max-width: 1200px; margin: 0 auto; display: flex; align-items: center; gap: 16px; }

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text);
}

.logo-icon { font-size: 28px; filter: drop-shadow(0 0 8px rgba(127,90,240,0.4)); }
.logo-text { font-family: var(--font-display); font-size: 24px; font-weight: 700; letter-spacing: -0.5px; }
.logo-dot { color: var(--accent); }
.tagline { font-size: 13px; color: var(--text-muted); font-weight: 300; letter-spacing: 1px; text-transform: uppercase; }

/* ═══ HERO ═════════════════════════════════════════════ */
#hero {
  position: relative;
  padding: 160px 24px 100px;
  text-align: center;
  overflow: hidden;
  min-height: 520px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: var(--gradient-hero);
  z-index: 0;
}

.hero-bg::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -30%;
  width: 800px;
  height: 800px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(127,90,240,0.12) 0%, transparent 70%);
  animation: pulse 8s ease-in-out infinite;
}

.hero-bg::after {
  content: '';
  position: absolute;
  bottom: -40%;
  left: -20%;
  width: 600px;
  height: 600px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(44,182,125,0.08) 0%, transparent 70%);
  animation: pulse 10s ease-in-out infinite reverse;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 0.5; }
  50% { transform: scale(1.15); opacity: 1; }
}

.hero-content { position: relative; z-index: 1; max-width: 700px; margin: 0 auto; }

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(2.2rem, 5vw, 3.8rem);
  font-weight: 700;
  line-height: 1.15;
  margin-bottom: 16px;
  letter-spacing: -1px;
}

.hero-title em {
  font-style: italic;
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-muted);
  margin-bottom: 40px;
  font-weight: 300;
  max-width: 520px;
  margin-left: auto;
  margin-right: auto;
}

/* ═══ SEARCH BOX ═══════════════════════════════════════ */
.search-box { max-width: 600px; margin: 0 auto; }

.search-input-wrap {
  display: flex;
  align-items: center;
  background: rgba(26,25,41,0.9);
  border: 1px solid rgba(127,90,240,0.2);
  border-radius: 60px;
  padding: 6px 6px 6px 20px;
  transition: var(--transition);
  box-shadow: var(--shadow-glow);
}

.search-input-wrap:focus-within {
  border-color: var(--accent);
  box-shadow: 0 0 40px rgba(127,90,240,0.25);
}

.search-icon { width: 20px; height: 20px; color: var(--text-muted); flex-shrink: 0; }

#search-input {
  flex: 1;
  background: none;
  border: none;
  color: var(--text);
  font-size: 16px;
  padding: 14px 12px;
  font-family: var(--font);
  outline: none;
}

#search-input::placeholder { color: var(--text-muted); }

#search-btn {
  padding: 12px 28px;
  background: var(--gradient-accent);
  color: white;
  border: none;
  border-radius: 50px;
  font-weight: 600;
  font-size: 15px;
  cursor: pointer;
  font-family: var(--font);
  transition: var(--transition);
  white-space: nowrap;
}

#search-btn:hover { transform: scale(1.05); box-shadow: 0 4px 20px rgba(127,90,240,0.4); }

/* ═══ LANGUAGE FILTER ══════════════════════════════════ */
.lang-filter {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 24px;
  flex-wrap: wrap;
  justify-content: center;
}

.lang-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.lang-pills {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: center;
}

.lang-pill {
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 6px 14px;
  border-radius: 50px;
  border: 1px solid rgba(127,90,240,0.15);
  background: rgba(26,25,41,0.7);
  color: var(--text-muted);
  font-size: 0.82rem;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  font-family: var(--font);
  white-space: nowrap;
}

.lang-pill:hover {
  border-color: var(--accent);
  color: var(--text);
  background: rgba(127,90,240,0.1);
}

.lang-pill.active {
  background: var(--gradient-accent);
  border-color: var(--accent);
  color: white;
  box-shadow: 0 2px 12px rgba(127,90,240,0.3);
}

.lang-pill .pill-flag { font-size: 1rem; }

/* ═══ SECTIONS ═════════════════════════════════════════ */
.section-title {
  font-family: var(--font-display);
  font-size: 1.8rem;
  font-weight: 700;
  margin-bottom: 32px;
  letter-spacing: -0.5px;
}

#categories-section, #featured-section, #results-section {
  padding: 60px 0;
}

#categories-section { background: var(--bg-surface); }

/* ═══ CATEGORIES ═══════════════════════════════════════ */
.categories-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 16px;
}

.category-card {
  background: var(--bg-card);
  border: 1px solid rgba(127,90,240,0.08);
  border-radius: var(--radius-sm);
  padding: 24px 16px;
  text-align: center;
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
  color: var(--text);
}

.category-card:hover {
  transform: translateY(-4px);
  background: var(--bg-card-hover);
  border-color: var(--accent);
  box-shadow: var(--shadow-glow);
}

.category-icon { font-size: 2rem; margin-bottom: 8px; display: block; }
.category-name { font-weight: 600; font-size: 0.95rem; }

/* ═══ BOOKS GRID ═══════════════════════════════════════ */
.books-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 24px;
}

.book-card {
  background: var(--bg-card);
  border: 1px solid rgba(127,90,240,0.06);
  border-radius: var(--radius);
  overflow: hidden;
  cursor: pointer;
  transition: var(--transition);
  position: relative;
}

.book-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(127,90,240,0.2);
}

.book-cover-wrap {
  width: 100%;
  aspect-ratio: 2/3;
  overflow: hidden;
  background: linear-gradient(135deg, #1e1b4b, #312e81);
  position: relative;
}

.book-cover {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.book-card:hover .book-cover { transform: scale(1.05); }

.book-cover-placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
  color: rgba(167,139,250,0.3);
  background: linear-gradient(135deg, #1e1b4b, #312e81);
}

.book-info { padding: 16px; }

.book-title {
  font-weight: 600;
  font-size: 0.95rem;
  line-height: 1.35;
  margin-bottom: 6px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.book-author {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 10px;
  display: -webkit-box;
  -webkit-line-clamp: 1;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.book-formats {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.format-badge {
  font-size: 0.7rem;
  padding: 3px 8px;
  border-radius: 20px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.format-badge.pdf { background: rgba(225,97,98,0.15); color: var(--accent3); }
.format-badge.epub { background: rgba(44,182,125,0.15); color: var(--accent2); }
.format-badge.txt { background: rgba(127,90,240,0.15); color: var(--accent-glow); }
.format-badge.gb { background: rgba(66,133,244,0.12); color: #7aafff; font-size: 0.65rem; }

/* ═══ RESULTS HEADER ═══════════════════════════════════ */
.results-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 32px; flex-wrap: wrap; gap: 12px; }

.btn-ghost {
  background: none;
  border: 1px solid rgba(127,90,240,0.3);
  color: var(--text-muted);
  padding: 8px 16px;
  border-radius: 50px;
  cursor: pointer;
  font-family: var(--font);
  font-size: 0.85rem;
  transition: var(--transition);
}

.btn-ghost:hover { border-color: var(--accent); color: var(--text); }

/* ═══ PAGINATION ═══════════════════════════════════════ */
.pagination {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-top: 40px;
  flex-wrap: wrap;
}

.page-btn {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  border: 1px solid rgba(127,90,240,0.2);
  background: var(--bg-card);
  color: var(--text);
  font-weight: 600;
  cursor: pointer;
  font-family: var(--font);
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
}

.page-btn:hover, .page-btn.active {
  background: var(--gradient-accent);
  border-color: var(--accent);
  transform: scale(1.1);
}

.page-btn:disabled { opacity: 0.3; pointer-events: none; }

/* ═══ LOADING ══════════════════════════════════════════ */
.loading { text-align: center; padding: 60px; color: var(--text-muted); }

.spinner {
  width: 40px;
  height: 40px;
  border: 3px solid rgba(127,90,240,0.2);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin: 0 auto 16px;
}

@keyframes spin { to { transform: rotate(360deg); } }

.no-results { text-align: center; padding: 60px; color: var(--text-muted); }
.no-results-icon { font-size: 3rem; margin-bottom: 12px; }

/* ═══ MODAL ════════════════════════════════════════════ */
.modal {
  position: fixed;
  inset: 0;
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.modal-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0,0,0,0.75);
  backdrop-filter: blur(8px);
}

.modal-content {
  position: relative;
  background: var(--bg-card);
  border: 1px solid rgba(127,90,240,0.15);
  border-radius: var(--radius);
  max-width: 560px;
  width: 100%;
  max-height: 85vh;
  overflow-y: auto;
  box-shadow: var(--shadow-lg);
  animation: modalIn 0.3s ease;
}

@keyframes modalIn {
  from { opacity: 0; transform: scale(0.95) translateY(20px); }
  to { opacity: 1; transform: scale(1) translateY(0); }
}

.modal-close {
  position: absolute;
  top: 16px;
  right: 16px;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: none;
  background: rgba(255,255,255,0.1);
  color: var(--text);
  font-size: 18px;
  cursor: pointer;
  z-index: 1;
  transition: var(--transition);
}

.modal-close:hover { background: var(--accent3); }

.modal-book-header { display: flex; gap: 20px; padding: 24px; }
.modal-cover { width: 140px; border-radius: var(--radius-sm); flex-shrink: 0; }
.modal-cover img { width: 100%; border-radius: var(--radius-sm); }
.modal-meta { flex: 1; }
.modal-title { font-family: var(--font-display); font-size: 1.35rem; margin-bottom: 8px; line-height: 1.3; }
.modal-author { color: var(--accent-glow); font-size: 0.95rem; margin-bottom: 12px; }
.modal-subjects { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 12px; }

.subject-tag {
  font-size: 0.72rem;
  padding: 3px 10px;
  border-radius: 20px;
  background: rgba(127,90,240,0.1);
  color: var(--text-muted);
  border: 1px solid rgba(127,90,240,0.15);
}

.modal-downloads { padding: 0 24px 24px; }
.modal-downloads h3 { font-size: 1rem; margin-bottom: 14px; color: var(--text-muted); font-weight: 500; }

.download-btns { display: flex; flex-direction: column; gap: 10px; }

.download-btn {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 20px;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(127,90,240,0.15);
  background: var(--bg-surface);
  color: var(--text);
  text-decoration: none;
  font-family: var(--font);
  font-weight: 500;
  transition: var(--transition);
  cursor: pointer;
}

.download-btn:hover {
  background: rgba(127,90,240,0.1);
  border-color: var(--accent);
  transform: translateX(4px);
}

.download-btn .dl-icon { font-size: 1.3rem; }
.download-btn .dl-format { font-weight: 700; text-transform: uppercase; font-size: 0.85rem; }
.download-btn .dl-label { flex: 1; font-size: 0.88rem; color: var(--text-muted); }
.download-btn .dl-arrow { color: var(--accent-glow); }

.modal-stats { padding: 0 24px 24px; font-size: 0.85rem; color: var(--text-muted); }

/* ═══ FOOTER ═══════════════════════════════════════════ */
#main-footer {
  padding: 40px 0;
  text-align: center;
  border-top: 1px solid rgba(127,90,240,0.08);
  background: var(--bg-surface);
}

.footer-text { color: var(--text-muted); font-size: 0.9rem; line-height: 1.8; }

/* ═══ RESPONSIVE ═══════════════════════════════════════ */
@media (max-width: 768px) {
  .categories-grid { grid-template-columns: repeat(auto-fill, minmax(130px, 1fr)); gap: 10px; }
  .books-grid { grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); gap: 16px; }
  .modal-book-header { flex-direction: column; align-items: center; text-align: center; }
  .modal-cover { width: 120px; }
  .hero-title { font-size: 2rem; }
  .tagline { display: none; }
}

@media (max-width: 480px) {
  .books-grid { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  #hero { padding: 130px 16px 60px; min-height: 400px; }
  .search-input-wrap { padding: 4px 4px 4px 14px; }
  #search-btn { padding: 10px 18px; font-size: 14px; }
}

/* ═══ SCROLLBAR ════════════════════════════════════════ */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: rgba(127,90,240,0.3); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--accent); }