/* ============================================================
   VARIABLES
   ============================================================ */
:root {
  --color-bg:           #ffffff;
  --color-surface:      #f8f9fa;
  --color-border:       #e9ecef;
  --color-text:         #1a1a2e;
  --color-text-muted:   #6c757d;
  --color-heading:      #0d1117;
  --color-accent:       #4f46e5;
  --color-accent-dark:  #3730a3;
  --color-accent-light: #eef2ff;
  --color-nav-bg:       rgba(255, 255, 255, 0.96);
  --color-footer-bg:    #0d1117;
  --color-footer-text:  #adb5bd;

  --font-body:    'DM Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-heading: 'Fraunces', Georgia, 'Times New Roman', serif;

  --radius:     0.75rem;
  --radius-sm:  0.375rem;
  --shadow-sm:  0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md:  0 4px 12px rgba(0,0,0,0.08), 0 2px 4px rgba(0,0,0,0.04);
  --shadow-lg:  0 12px 24px rgba(0,0,0,0.10), 0 4px 8px rgba(0,0,0,0.05);
  --transition: 200ms ease;
}

/* ============================================================
   BASE
   ============================================================ */
*, *::before, *::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  height: 100%;
}

body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.75;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

#main-content {
  flex: 1 0 auto;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  color: var(--color-heading);
  line-height: 1.25;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition);
}
a:hover { color: var(--color-accent-dark); }

img { max-width: 100%; height: auto; }

/* ============================================================
   NAVBAR
   ============================================================ */
.site-navbar {
  background: var(--color-nav-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  padding: 0.75rem 0;
  box-shadow: var(--shadow-sm);
}

.site-brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--color-heading) !important;
}
.site-brand:hover { color: var(--color-accent) !important; }

.brand-icon {
  color: var(--color-accent);
  font-size: 1.1rem;
}

.site-navbar .nav-link {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-muted) !important;
  padding: 0.4rem 0.75rem !important;
  border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition);
}
.site-navbar .nav-link:hover,
.site-navbar .nav-link.active {
  color: var(--color-accent) !important;
  background: var(--color-accent-light);
}

.navbar-scrolled {
  padding: 0.35rem 0;
  box-shadow: var(--shadow-md);
}

/* Offcanvas mobile nav */
.site-offcanvas {
  border-left: 1px solid var(--color-border);
}

.site-offcanvas .offcanvas-header {
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--color-border);
}

.site-offcanvas .offcanvas-body {
  padding: 1.5rem;
}

.offcanvas-nav {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.offcanvas-link {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  padding: 0.85rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 1.05rem;
  font-weight: 500;
  color: var(--color-text);
  text-decoration: none;
  transition: background var(--transition), color var(--transition);
}
.offcanvas-link i {
  width: 1.1rem;
  text-align: center;
  color: var(--color-text-muted);
  font-size: 0.95rem;
  transition: color var(--transition);
}
.offcanvas-link:hover {
  background: var(--color-accent-light);
  color: var(--color-accent);
}
.offcanvas-link:hover i {
  color: var(--color-accent);
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
  padding: 5rem 0 4rem;
  border-bottom: 1px solid var(--color-border);
  background: linear-gradient(135deg, #fafbff 0%, #f0f2ff 100%);
}

.hero-inner {
  max-width: 640px;
}

.hero-eyebrow {
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: 0.75rem;
}

.hero-title {
  font-size: clamp(2.4rem, 5vw, 3.5rem);
  font-weight: 700;
  margin-bottom: 1rem;
  line-height: 1.15;
}

.hero-desc {
  font-size: 1.15rem;
  color: var(--color-text-muted);
  margin-bottom: 0;
  max-width: 520px;
}

/* ============================================================
   BUTTONS
   ============================================================ */
.btn-accent {
  background: var(--color-accent);
  color: #fff !important;
  border: none;
  border-radius: var(--radius-sm);
  padding: 0.55rem 1.4rem;
  font-size: 0.9rem;
  font-weight: 500;
  transition: background var(--transition), box-shadow var(--transition), transform var(--transition);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}
.btn-accent:hover {
  background: var(--color-accent-dark);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

/* ============================================================
   SECTIONS
   ============================================================ */
.section-featured,
.section-posts {
  padding: 3rem 0;
}

@media (min-width: 1400px) {
  .post-container,
  .hero .container,
  .section-featured .container,
  .section-posts .container {
    max-width: 1050px;
  }
}

.section-label {
  font-family: var(--font-body);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  border-bottom: 2px solid var(--color-border);
  padding-bottom: 0.75rem;
  margin-bottom: 1.75rem;
}

/* ============================================================
   FEATURED CARD
   ============================================================ */
.featured-card {
  display: flex;
  gap: 1.5rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  text-decoration: none;
  color: inherit;
  transition: box-shadow var(--transition), transform var(--transition);
  background: var(--color-surface);
}
.featured-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}
.featured-cover {
  flex: 0 0 280px;
  overflow: hidden;
}
.featured-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 400ms ease;
}
.featured-card:hover .featured-cover img { transform: scale(1.03); }

.featured-body {
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
}
.featured-title {
  font-size: 1.5rem;
  margin-bottom: 0.5rem;
  color: var(--color-heading);
}
.featured-summary {
  color: var(--color-text-muted);
  font-size: 0.95rem;
  flex-grow: 1;
}
.read-more {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-accent);
}

@media (max-width: 767px) {
  .featured-card { flex-direction: column; }
  .featured-cover { flex: none; height: 200px; }
}

/* ============================================================
   POST CARDS
   ============================================================ */
.post-list {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.post-card {
  display: flex;
  gap: 1.25rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
  background: var(--color-bg);
  transition: box-shadow var(--transition), transform var(--transition), border-color var(--transition);
}
.post-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
  border-color: #d0d7de;
}

.post-card-body { flex: 1; min-width: 0; }

.post-card-title {
  font-size: 1.15rem;
  margin-bottom: 0.4rem;
  font-weight: 700;
}
.post-card-title a {
  color: var(--color-heading);
  text-decoration: none;
}
.post-card-title a:hover { color: var(--color-accent); }

.post-card-summary {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  margin-bottom: 0;
  line-height: 1.6;
}

.post-card-cover {
  flex: 0 0 100px;
  height: 80px;
  border-radius: var(--radius-sm);
  overflow: hidden;
}
.post-card-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ============================================================
   TAGS
   ============================================================ */
.tag-list { display: flex; flex-wrap: wrap; gap: 0.35rem; }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  background: var(--color-accent-light);
  color: var(--color-accent);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
  text-decoration: none;
  transition: background var(--transition), color var(--transition);
  border: 1px solid transparent;
}
.tag:hover {
  background: var(--color-accent);
  color: #fff;
}
.tag-active {
  background: var(--color-accent);
  color: #fff;
}
.tag-sm { font-size: 0.7rem; padding: 0.15rem 0.45rem; }

.tag-count {
  background: rgba(255,255,255,0.5);
  border-radius: 999px;
  padding: 0 0.4rem;
  font-size: 0.7rem;
}

/* Tag cloud */
.tag-cloud { display: flex; flex-wrap: wrap; gap: 0.4rem; }

/* Tag index */
.tag-index {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1rem;
}
.tag-index-item {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-text);
  font-size: 0.9rem;
  text-decoration: none;
  transition: all var(--transition);
}
.tag-index-item:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background: var(--color-accent-light);
}
.tag-index-count {
  background: var(--color-surface);
  border-radius: 999px;
  padding: 0.1rem 0.5rem;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-text-muted);
}

/* ============================================================
   POST META
   ============================================================ */
.post-meta {
  font-size: 0.8rem;
  color: var(--color-text-muted);
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem;
  align-items: center;
}

/* ============================================================
   SIDEBAR
   ============================================================ */
.sidebar { position: sticky; top: 5rem; }

.sidebar-widget {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.25rem;
  margin-bottom: 1.25rem;
}

.sidebar-title {
  font-family: var(--font-body);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: 0.85rem;
}

/* ============================================================
   POST PAGE
   ============================================================ */
.post-container { padding-top: 2.5rem; padding-bottom: 4rem; }

.post-breadcrumb { margin-bottom: 2rem; }
.breadcrumb { font-size: 0.82rem; }
.breadcrumb-item a { color: var(--color-accent); }

.post-header { margin-bottom: 2rem; }

.post-title {
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 0.75rem;
}

.post-summary {
  font-size: 1.1rem;
  color: var(--color-text-muted);
  font-weight: 400;
  line-height: 1.6;
  margin-bottom: 1.25rem;
}

.post-byline {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem;
  align-items: center;
  padding-top: 1rem;
  border-top: 1px solid var(--color-border);
}

.post-cover {
  margin-bottom: 2rem;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

/* Post body typography */
.post-body {
  font-size: 1.05rem;
  line-height: 1.85;
  color: var(--color-text);
}

.post-body h2 {
  font-size: 1.5rem;
  margin-top: 2.5rem;
  margin-bottom: 0.85rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--color-border);
}
.post-body h3 {
  font-size: 1.2rem;
  margin-top: 2rem;
  margin-bottom: 0.6rem;
}
.post-body h4 { font-size: 1.05rem; margin-top: 1.5rem; }

.post-body p { margin-bottom: 1.4rem; }

.post-body a {
  color: var(--color-accent);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.post-body blockquote {
  border-left: 4px solid var(--color-accent);
  background: var(--color-accent-light);
  padding: 1rem 1.5rem;
  margin: 1.75rem 0;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-style: italic;
  color: var(--color-text-muted);
}

.post-body pre {
  margin: 1.5rem 0;
  border-radius: var(--radius-sm);
  padding: 1.25rem;
  font-size: 0.875rem;
  line-height: 1.6;
  overflow: hidden;
  background: #14161a;
  color: #abb2bf;
}

/* hljs añade esta clase al <code> tras procesar — especificidad 0,2,2 */
.post-body pre code.hljs {
  border-radius: 0;
  font-size: inherit;
  line-height: inherit;
  overflow-x: auto;
  color: #abb2bf;
}

.post-body code {
  font-size: 0.875em;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  padding: 0.15em 0.45em;
  border-radius: var(--radius-sm);
  color: #d63384;
}

.post-body pre code {
  background: none;
  border: none;
  padding: 0;
  color: #abb2bf;
}

.post-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.9rem;
}
.post-body th {
  background: var(--color-surface);
  padding: 0.65rem 1rem;
  border: 1px solid var(--color-border);
  font-weight: 600;
  text-align: left;
}
.post-body td {
  padding: 0.55rem 1rem;
  border: 1px solid var(--color-border);
}
.post-body tr:nth-child(even) { background: var(--color-surface); }

.post-body ul, .post-body ol {
  padding-left: 1.5rem;
  margin-bottom: 1.4rem;
}
.post-body li { margin-bottom: 0.35rem; }

.post-body img {
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-sm);
  margin: 1rem auto;
  display: block;
}

.post-body hr {
  border: none;
  border-top: 2px solid var(--color-border);
  margin: 2rem 0;
}

/* Post footer */
.post-footer {
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--color-border);
}

.post-tags { display: flex; flex-wrap: wrap; align-items: center; gap: 0.4rem; }

/* Prev/Next navigation */
.post-nav {
  margin-top: 1.5rem;
  padding-top: 2rem;
  border-top: 2px solid var(--color-border);
}

.post-nav-link {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding: 1rem 1.25rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  text-decoration: none;
  color: inherit;
  transition: all var(--transition);
}
.post-nav-link:hover {
  border-color: var(--color-accent);
  background: var(--color-accent-light);
}

.post-nav-label {
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-muted);
}
.post-nav-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--color-heading);
  line-height: 1.35;
}
.post-nav-next .post-nav-label { text-align: right; }
.post-nav-next .post-nav-title { text-align: right; }

/* ============================================================
   PAGE HEADER
   ============================================================ */
.page-header { margin-bottom: 2.5rem; }
.page-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  margin-bottom: 0.5rem;
}

/* ============================================================
   ARCHIVE
   ============================================================ */
.archive-list { margin-top: 1rem; }

.archive-month { margin-bottom: 2.5rem; }

.archive-month-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-heading);
  margin-bottom: 0.75rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.archive-count {
  font-size: 0.75rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 999px;
  padding: 0 0.55rem;
  color: var(--color-text-muted);
  font-family: var(--font-body);
  font-weight: 600;
}

.archive-entries {
  list-style: none;
  padding: 0;
  margin: 0;
  border-left: 2px solid var(--color-border);
  padding-left: 1.25rem;
}

.archive-entry {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  padding: 0.45rem 0;
  font-size: 0.9rem;
}

.archive-date {
  flex-shrink: 0;
  color: var(--color-text-muted);
  font-size: 0.8rem;
  min-width: 50px;
}

.archive-title {
  color: var(--color-text);
  text-decoration: none;
  font-weight: 500;
  transition: color var(--transition);
}
.archive-title:hover { color: var(--color-accent); }

.archive-tags { display: flex; gap: 0.3rem; flex-wrap: wrap; }

/* ============================================================
   404
   ============================================================ */
.error-page { padding: 5rem 0 3rem; }

.error-code {
  font-family: var(--font-heading);
  font-size: 8rem;
  font-weight: 700;
  color: var(--color-border);
  line-height: 1;
  margin-bottom: 0.5rem;
}

.error-title {
  font-size: 1.75rem;
  margin-bottom: 0.75rem;
}

.error-desc { font-size: 1rem; }

.post-link {
  color: var(--color-text);
  font-weight: 500;
  text-decoration: none;
}
.post-link:hover { color: var(--color-accent); }

/* ============================================================
   EMPTY STATE
   ============================================================ */
.empty-state {
  text-align: center;
  padding: 3rem 1rem;
  color: var(--color-text-muted);
  border: 2px dashed var(--color-border);
  border-radius: var(--radius);
}

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
  flex-shrink: 0;
  background: var(--color-footer-bg);
  color: var(--color-footer-text);
  padding: 2.5rem 0;
  border-top: 1px solid #1e1e2e;
}

.footer-brand {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 700;
  color: #fff;
}

.footer-desc {
  font-size: 0.85rem;
  color: var(--color-footer-text);
}

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

.footer-links a {
  color: var(--color-footer-text);
  font-size: 1rem;
  transition: color var(--transition);
}
.footer-links a:hover { color: #fff; }

.footer-copy {
  font-size: 0.8rem;
  color: #6c757d;
}

/* ============================================================
   ANIMATE.CSS SCROLL INTEGRATION
   ============================================================ */
.animate-on-scroll {
  opacity: 0;
}
.animate-on-scroll.animated {
  opacity: 1;
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 991px) {
  .post-sidebar { display: none; }
  .hero { padding: 3.5rem 0 3rem; }
}

@media (max-width: 767px) {
  .post-card { flex-direction: column; }
  .post-card-cover { display: none; }
  .archive-entry { flex-wrap: wrap; gap: 0.4rem; }
  .post-nav .row { flex-direction: column; }
  .post-nav-next .post-nav-label,
  .post-nav-next .post-nav-title { text-align: left; }
  .footer-links { justify-content: flex-start; }
}

@media (max-width: 575px) {
  .hero-title { font-size: 2rem; }
  .post-title { font-size: 1.6rem; }
}

/* ============================================================
   MATH (KaTeX)
   ============================================================ */
.math-display {
  overflow-x: auto;
  text-align: center;
  margin: 1.5rem 0;
  padding: 0.25rem 0;
}

.math-inline {
  white-space: nowrap;
}

/* Prevent KaTeX from inheriting the serif heading font */
.post-body .katex {
  font-size: 1.05em;
}