:root {
  /* ---- mismos tokens de color que el site principal ---- */
  --bg:        #F7F6F1;
  --bg-raise:  #FFFFFF;
  --ink:       #10160F;
  --ink-soft:  #384038;
  --muted:     #667066;
  --line:      rgba(16, 22, 15, 0.12);
  --line-soft: rgba(16, 22, 15, 0.07);
  --green:     #0CA968;
  --green-deep:#0B3D2A;
  --green-soft:rgba(12, 169, 104, 0.09);
  --green-line:rgba(12, 169, 104, 0.28);
  --bad:       #A23B33;
  --bad-soft:  rgba(162, 59, 51, 0.08);
  --amber:     #9A6B12;
  --amber-soft:rgba(154, 107, 18, 0.09);

  /* ---- misma tipografía ---- */
  --f-display: 'Fraunces', serif;
  --f-body:    'DM Sans', system-ui, sans-serif;
  --f-mono:    'Space Mono', monospace;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

body {
  font-family: var(--f-body);
  background: var(--bg);
  color: var(--ink-soft);
  line-height: 1.7;
  font-size: 15.5px;
}

a { color: var(--green-deep); }

/* =======================================================
   BACK LINK
   ======================================================= */
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  position: sticky;
  top: 0;
  z-index: 50;
  width: 100%;
  padding: 16px 48px;
  background: rgba(247, 246, 241, 0.9);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
  font-size: 13.5px;
  font-weight: 600;
  color: var(--muted);
  text-decoration: none;
}
.back-link:hover { color: var(--green-deep); }

/* =======================================================
   COVER
   ======================================================= */
.cover {
  background: var(--ink);
  color: #F7F6F1;
  padding: 96px 48px 84px;
  text-align: center;
  position: relative;
  isolation: isolate;
  overflow: hidden;
}

.cover::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(55% 45% at 80% 25%, rgba(12,169,104,0.16) 0%, transparent 70%),
    radial-gradient(40% 35% at 15% 90%, rgba(12,169,104,0.08) 0%, transparent 70%);
  pointer-events: none;
  z-index: 0;
}

.cover-inner { position: relative; z-index: 1; max-width: 720px; margin: 0 auto; }

.cover h1 {
  font-family: var(--f-display);
  font-weight: 500;
  font-size: clamp(34px, 5.5vw, 56px);
  letter-spacing: -0.01em;
  color: #F2F0E8;
  margin-bottom: 14px;
}

.cover .tagline {
  font-family: var(--f-mono);
  font-size: 13.5px;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--green);
  margin-bottom: 32px;
}

.cover .meta {
  font-size: 13px;
  color: rgba(247,246,241,0.55);
  line-height: 1.8;
}

/* =======================================================
   ABSTRACT
   ======================================================= */
.abstract-box {
  max-width: 760px;
  margin: -40px auto 0;
  background: var(--bg-raise);
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 40px 44px;
  position: relative;
  z-index: 2;
  box-shadow: 0 30px 60px rgba(16,22,15,.08);
}

.abstract-box h2 {
  font-family: var(--f-display);
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--green-deep);
  margin-bottom: 16px;
}

.abstract-box p { margin-bottom: 14px; color: var(--ink-soft); }
.abstract-box p:last-of-type { margin-bottom: 20px; }

.legal-notice {
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 16px 18px;
  font-size: 13px;
  color: var(--muted);
  line-height: 1.6;
}
.legal-notice strong {
  display: block;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--ink);
  margin-bottom: 6px;
}

/* =======================================================
   TOC
   ======================================================= */
.toc {
  max-width: 760px;
  margin: 40px auto 0;
  padding: 0 48px;
}

.toc h2 {
  font-family: var(--f-display);
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--muted);
  margin-bottom: 14px;
}

.toc ol {
  list-style: none;
  counter-reset: toc-counter;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--bg-raise);
  overflow: hidden;
}

.toc li {
  counter-increment: toc-counter;
  border-bottom: 1px solid var(--line-soft);
}
.toc li:last-child { border-bottom: none; }

.toc a {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 20px;
  text-decoration: none;
  color: var(--ink-soft);
  font-size: 14px;
  font-weight: 500;
  transition: background .15s, color .15s;
}
.toc a:hover { background: var(--green-soft); color: var(--green-deep); }

.toc a::before {
  content: counter(toc-counter);
  font-family: var(--f-mono);
  font-size: 12px;
  font-weight: 700;
  color: var(--green-deep);
  min-width: 20px;
}

/* =======================================================
   MAIN CONTENT
   ======================================================= */
main {
  max-width: 760px;
  margin: 0 auto;
  padding: 56px 48px 40px;
}

section { margin-bottom: 64px; scroll-margin-top: 76px; }
section:last-child { margin-bottom: 0; }

.section-title {
  font-family: var(--f-display);
  font-size: clamp(24px, 3vw, 30px);
  font-weight: 500;
  color: var(--ink);
  letter-spacing: -0.3px;
  margin-bottom: 20px;
  padding-bottom: 16px;
  border-bottom: 2px solid var(--ink);
}

.subsection-title {
  font-family: var(--f-display);
  font-size: 19px;
  font-weight: 500;
  color: var(--ink);
  margin: 32px 0 12px;
}

section p { margin-bottom: 14px; }
section ul { margin: 0 0 16px 0; padding-left: 22px; }
section ul li { margin-bottom: 8px; }
section > p:first-of-type { margin-top: 0; }

strong { color: var(--ink); font-weight: 700; }

/* =======================================================
   EQUATION / CODE BLOCKS
   ======================================================= */
.equation {
  background: var(--ink);
  border-radius: 12px;
  padding: 20px 24px;
  margin: 18px 0;
  overflow-x: auto;
}

.equation code {
  font-family: var(--f-mono);
  font-size: 13px;
  color: #cdeee0;
  white-space: pre;
  line-height: 1.8;
}

.caption {
  font-size: 12.5px;
  color: var(--muted);
  font-style: italic;
  margin-top: -6px;
  margin-bottom: 18px;
}

/* =======================================================
   TABLES
   ======================================================= */
.table-wrap {
  width: 100%;
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: 14px;
  margin: 18px 0 4px;
  background: var(--bg-raise);
}

table { width: 100%; border-collapse: collapse; font-size: 13px; min-width: 480px; }

th, td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: 1px solid var(--line-soft);
  line-height: 1.5;
}

th {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .05em;
  color: var(--muted);
  border-bottom: 1px solid var(--line);
}

tr:last-child td { border-bottom: none; }
td { color: var(--ink-soft); }

/* =======================================================
   BADGES
   ======================================================= */
.badge {
  display: inline-block;
  font-size: 10.5px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .04em;
  padding: 3px 10px;
  border-radius: 100px;
  white-space: nowrap;
}

.badge-done { color: var(--green-deep); background: var(--green-soft); border: 1px solid var(--green-line); }
.badge-progress { color: var(--amber); background: var(--amber-soft); border: 1px solid rgba(154,107,18,0.25); }
.badge-planned { color: var(--muted); background: var(--line-soft); border: 1px solid var(--line); }

/* =======================================================
   NOTE
   ======================================================= */
.note {
  background: var(--amber-soft);
  border: 1px solid rgba(154,107,18,0.25);
  border-radius: 12px;
  padding: 16px 18px;
  font-size: 13.5px;
  color: var(--ink-soft);
  margin: 16px 0;
}

/* =======================================================
   CONTRACT TITLES (Sección 6)
   ======================================================= */
.contract-title {
  font-family: var(--f-mono);
  font-size: 14.5px;
  font-weight: 700;
  color: var(--green-deep);
  background: var(--green-soft);
  border-left: 3px solid var(--green);
  padding: 10px 16px;
  border-radius: 0 8px 8px 0;
  margin: 28px 0 12px;
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

/* =======================================================
   REFERENCES
   ======================================================= */
#s9 ul { list-style: none; padding-left: 0; }
#s9 li {
  font-size: 12.5px;
  color: var(--muted);
  padding: 8px 0;
  border-bottom: 1px solid var(--line-soft);
}
#s9 li:last-child { border-bottom: none; }

/* =======================================================
   FOOTER
   ======================================================= */
footer {
  max-width: 760px;
  margin: 0 auto;
  padding: 32px 48px 64px;
  border-top: 1px solid var(--line);
  text-align: center;
}

footer p { font-size: 12.5px; color: var(--muted); margin-bottom: 8px; }
footer .brand { font-family: var(--f-display); font-weight: 500; color: var(--ink); }

/* =======================================================
   RESPONSIVE
   ======================================================= */
@media (max-width: 640px) {
  .back-link { padding: 14px 20px; }
  .cover { padding: 64px 20px 56px; }
  .abstract-box { margin: -28px 16px 0; padding: 28px 22px; border-radius: 16px; }
  .toc { padding: 0 20px; }
  main { padding: 40px 20px 24px; }
  .section-title { font-size: 24px; }
  footer { padding: 28px 20px 48px; }
}