/* ─── Design Tokens ─────────────────────────────────────── */
:root {
  --teal:       #096B72;
  --teal-light: #0a8a93;
  --teal-dark:  #064e54;
  --navy:       #0c1b2a;
  --navy-mid:   #122234;
  --gold:       #c9a84c;
  --text:       #1a1a2e;
  --text-muted: #5a6070;
  --bg:         #f8f7f4;
  --bg-alt:     #eef2f3;
  --card-bg:    #ffffff;
  --border:     #dde3e7;
  --radius:     14px;
  --shadow:     0 4px 32px rgba(9,107,114,.12);
  --shadow-lg:  0 12px 56px rgba(9,107,114,.20);
  --transition: .3s cubic-bezier(.4,0,.2,1);
  --font-body:  'Merriweather', Georgia, serif;
  --font-ui:    'Open Sans', system-ui, sans-serif;
}

/* ─── Dark Mode ──────────────────────────────────────────── */
@media (prefers-color-scheme: dark) {
  :root {
    --text:      #e8eaf0;
    --text-muted:#8a95a5;
    --bg:        #0d1117;
    --bg-alt:    #161b22;
    --card-bg:   #1c2333;
    --border:    #2d3748;
    --shadow:    0 4px 32px rgba(0,0,0,.4);
    --shadow-lg: 0 12px 56px rgba(0,0,0,.5);
  }
}

/* ─── Reset & Base ───────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: var(--font-body);
  background-color: var(--bg);
  color: var(--text);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--teal); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--teal-light); }

img { max-width: 100%; display: block; }

/* ─── Layout ─────────────────────────────────────────────── */
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section {
  padding: 5rem 0;
}

/* ─── Nav ────────────────────────────────────────────────── */
.nav-bar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: transparent;
  transition: background var(--transition), box-shadow var(--transition);
}

.nav-bar.nav-scrolled {
  background: rgba(12, 27, 42, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 1px 0 rgba(255,255,255,.08);
}

.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: .9rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-family: var(--font-ui);
  font-weight: 700;
  font-size: 1.05rem;
  color: #fff;
  letter-spacing: .02em;
}

.nav-link {
  font-family: var(--font-ui);
  font-size: .88rem;
  font-weight: 600;
  color: rgba(255,255,255,.8);
  margin-left: 2rem;
  letter-spacing: .04em;
  text-transform: uppercase;
  transition: color var(--transition);
}
.nav-link:hover { color: #fff; }

/* ─── Hero ───────────────────────────────────────────────── */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 70% 80% at 30% 40%, rgba(9,107,114,.55) 0%, transparent 65%),
    radial-gradient(ellipse 60% 60% at 80% 70%, rgba(6,78,84,.4) 0%, transparent 70%),
    linear-gradient(135deg, #0c1b2a 0%, #122234 50%, #0d2a35 100%);
  z-index: 0;
}

/* Subtle animated grid pattern */
.hero-bg::after {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(9,107,114,.08) 1px, transparent 1px),
    linear-gradient(90deg, rgba(9,107,114,.08) 1px, transparent 1px);
  background-size: 60px 60px;
  animation: gridPan 20s linear infinite;
}

@keyframes gridPan {
  from { background-position: 0 0; }
  to   { background-position: 60px 60px; }
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 1100px;
  margin: 0 auto;
  padding: 7rem 1.5rem 5rem;
}

.hero-label {
  display: inline-block;
  font-family: var(--font-ui);
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--gold);
  margin-bottom: 1.25rem;
  border-left: 3px solid var(--gold);
  padding-left: .75rem;
}

.hero-title {
  font-size: clamp(2.8rem, 6vw, 5rem);
  font-weight: 300;
  color: #fff;
  line-height: 1.1;
  margin-bottom: 1.5rem;
  letter-spacing: -.02em;
}
.hero-title em {
  font-style: normal;
  font-weight: 700;
  color: var(--teal-light);
}

.hero-sub {
  max-width: 600px;
  font-size: 1.1rem;
  color: rgba(255,255,255,.7);
  line-height: 1.8;
  margin-bottom: 2.5rem;
}

.hero-actions { display: flex; gap: 1rem; flex-wrap: wrap; }

/* ─── Buttons ────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  font-family: var(--font-ui);
  font-weight: 700;
  font-size: .88rem;
  letter-spacing: .06em;
  text-transform: uppercase;
  padding: .85rem 2rem;
  border-radius: 8px;
  transition: all var(--transition);
  cursor: pointer;
  border: 2px solid transparent;
}

.btn-primary {
  background: var(--teal);
  color: #fff;
  box-shadow: 0 4px 24px rgba(9,107,114,.35);
}
.btn-primary:hover {
  background: var(--teal-light);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(9,107,114,.45);
}

.btn-ghost {
  background: transparent;
  color: rgba(255,255,255,.8);
  border-color: rgba(255,255,255,.25);
}
.btn-ghost:hover {
  border-color: rgba(255,255,255,.6);
  color: #fff;
  transform: translateY(-2px);
}

.btn-disabled {
  opacity: .45;
  cursor: not-allowed;
  pointer-events: none;
  background: transparent;
  border-color: var(--border);
  color: var(--text-muted);
}

/* ─── Scroll hint ────────────────────────────────────────── */
.hero-scroll-hint {
  position: absolute;
  bottom: 2.5rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
}
.hero-scroll-hint span {
  display: block;
  width: 24px;
  height: 40px;
  border: 2px solid rgba(255,255,255,.25);
  border-radius: 12px;
  position: relative;
}
.hero-scroll-hint span::after {
  content: '';
  position: absolute;
  top: 6px;
  left: 50%;
  transform: translateX(-50%);
  width: 4px;
  height: 8px;
  background: rgba(255,255,255,.55);
  border-radius: 2px;
  animation: scrollDot 2s ease-in-out infinite;
}
@keyframes scrollDot {
  0%   { opacity: 1; transform: translateX(-50%) translateY(0); }
  100% { opacity: 0; transform: translateX(-50%) translateY(14px); }
}

/* ─── Section Header ─────────────────────────────────────── */
.section-header {
  margin-bottom: 3rem;
}

.section-header h2 {
  font-size: clamp(1.8rem, 3vw, 2.6rem);
  font-weight: 700;
  letter-spacing: -.01em;
  margin-bottom: .75rem;
}

.section-rule {
  width: 56px;
  height: 4px;
  background: linear-gradient(90deg, var(--teal), var(--gold));
  border-radius: 2px;
  margin-bottom: 1rem;
}

.section-sub {
  font-family: var(--font-ui);
  color: var(--text-muted);
  font-size: 1rem;
}

/* ─── Sobre ──────────────────────────────────────────────── */
.sobre { background: var(--bg-alt); }

.sobre-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: start;
}

@media (max-width: 768px) {
  .sobre-grid { grid-template-columns: 1fr; gap: 2.5rem; }
}

.sobre-text p {
  margin-bottom: 1.25rem;
  color: var(--text-muted);
  font-size: .97rem;
}
.sobre-text p:last-child { margin-bottom: 0; }

.sobre-stats {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.stat-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem 1.75rem;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  gap: .35rem;
  transition: transform var(--transition), box-shadow var(--transition);
  border-left: 4px solid var(--teal);
}
.stat-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

.stat-number {
  font-family: var(--font-ui);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--teal);
  line-height: 1.2;
}
.stat-label {
  font-family: var(--font-ui);
  font-size: .82rem;
  color: var(--text-muted);
}

/* ─── Publicaciones ──────────────────────────────────────── */
.publicaciones { background: var(--bg); }

.books-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
}

.book-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: row;
  overflow: hidden;
  transition: transform var(--transition), box-shadow var(--transition);
}
.book-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.book-card--soon {
  opacity: .7;
}
.book-card--soon:hover { transform: none; box-shadow: var(--shadow); }

.book-spine {
  width: 10px;
  flex-shrink: 0;
  background: linear-gradient(180deg, var(--teal), var(--teal-dark));
}
.book-spine--alt {
  background: linear-gradient(180deg, #4a5568, #2d3748);
}

.book-card-body {
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  gap: .9rem;
}

.book-meta { display: flex; gap: .5rem; flex-wrap: wrap; }

.book-tag {
  font-family: var(--font-ui);
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  background: rgba(9,107,114,.1);
  color: var(--teal);
  padding: .25rem .6rem;
  border-radius: 4px;
  border: 1px solid rgba(9,107,114,.2);
}
@media (prefers-color-scheme: dark) {
  .book-tag { background: rgba(9,107,114,.25); border-color: rgba(9,107,114,.4); }
}

.book-title {
  font-size: 1.2rem;
  font-weight: 700;
  line-height: 1.3;
}

.book-desc {
  font-size: .9rem;
  color: var(--text-muted);
  line-height: 1.7;
}

.book-chapters {
  list-style: none;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: .4rem;
}
.book-chapters li {
  font-family: var(--font-ui);
  font-size: .83rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: .5rem;
}
.book-chapters li::before {
  content: '';
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--teal);
  flex-shrink: 0;
}

.book-cta { align-self: flex-start; margin-top: .5rem; }

/* ─── Footer ─────────────────────────────────────────────── */
.footer {
  background: var(--navy);
  padding: 3rem 0;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
  text-align: center;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: .3rem;
}

.footer-name {
  font-family: var(--font-ui);
  font-weight: 700;
  font-size: 1.05rem;
  color: #fff;
}

.footer-tagline {
  font-family: var(--font-ui);
  font-size: .8rem;
  color: rgba(255,255,255,.45);
  letter-spacing: .06em;
  text-transform: uppercase;
}

.footer-links { display: flex; gap: 1rem; }

.footer-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  border: 1px solid rgba(255,255,255,.15);
  color: rgba(255,255,255,.6);
  transition: all var(--transition);
}
.footer-icon:hover {
  background: var(--teal);
  border-color: var(--teal);
  color: #fff;
  transform: translateY(-2px);
}

.footer-copy {
  font-family: var(--font-ui);
  font-size: .8rem;
  color: rgba(255,255,255,.35);
}
.footer-copy a { color: rgba(255,255,255,.5); }
.footer-copy a:hover { color: rgba(255,255,255,.8); }

/* ─── Utilities ──────────────────────────────────────────── */
@media (max-width: 500px) {
  .hero-title { font-size: 2.4rem; }
  .nav-link { display: none; }
  .books-grid { grid-template-columns: 1fr; }
}