/* ==========================================================================
   ZHAVIA.LAT — DESIGN TOKENS & SYSTEM
   Inspiración: addyosmani.com | Alta densidad, minimalismo sobrio y editorial
   ========================================================================== */

:root {
  --bg-primary: #0F172A;
  --bg-secondary: #131E35;
  --bg-surface: #1E293B;
  --bg-surface-elevated: #24344D;
  --bg-code: #0A0F1D;
  
  --text-primary: #F8FAFC;
  --text-secondary: #94A3B8;
  --text-muted: #64748B;
  --text-accent: #38BDF8;

  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-focus: rgba(56, 189, 248, 0.4);
  --border-strong: rgba(255, 255, 255, 0.16);

  --accent-tech: #2563EB;
  --accent-tech-light: #38BDF8;
  --accent-emerald: #10B981;
  --accent-emerald-dark: #059669;
  --accent-amber: #F59E0B;
  --accent-pink: #EC4899;

  --font-display: 'Plus Jakarta Sans', system-ui, -apple-system, sans-serif;
  --font-body: 'Inter', system-ui, -apple-system, sans-serif;
  --font-editorial: 'Merriweather', Georgia, serif;
  --font-mono: 'JetBrains Mono', Consolas, monospace;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;

  --shadow-subtle: 0 4px 20px rgba(0, 0, 0, 0.25);
  --shadow-elevated: 0 12px 36px rgba(0, 0, 0, 0.45);
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --max-width: 1160px;
  color-scheme: dark;
}

[data-theme="light"] {
  --bg-primary: #FAFAFA;
  --bg-secondary: #F1F5F9;
  --bg-surface: #FFFFFF;
  --bg-surface-elevated: #F8FAFC;
  --bg-code: #0F172A;

  --text-primary: #0F172A;
  --text-secondary: #475569;
  --text-muted: #64748B;
  --text-accent: #0284C7;

  --border-subtle: rgba(0, 0, 0, 0.08);
  --border-focus: rgba(2, 132, 199, 0.4);
  --border-strong: rgba(0, 0, 0, 0.16);

  --accent-tech: #1D4ED8;
  --accent-tech-light: #0284C7;
  --accent-emerald: #059669;
  --accent-emerald-dark: #047857;

  --shadow-subtle: 0 4px 16px rgba(0, 0, 0, 0.06);
  --shadow-elevated: 0 12px 30px rgba(0, 0, 0, 0.1);
  color-scheme: light;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-body);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
  position: relative;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

.container {
  width: 100%;
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

.bg-grid-pattern {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 600px;
  background-image: radial-gradient(var(--border-subtle) 1px, transparent 1px);
  background-size: 28px 28px;
  mask-image: linear-gradient(to bottom, rgba(0,0,0,1), rgba(0,0,0,0));
  -webkit-mask-image: linear-gradient(to bottom, rgba(0,0,0,1), rgba(0,0,0,0));
  pointer-events: none;
  z-index: 0;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.25;
  color: var(--text-primary);
}

p {
  color: var(--text-secondary);
}

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

a:hover {
  text-decoration: underline;
}

.gradient-text {
  background: linear-gradient(135deg, var(--accent-tech-light) 0%, var(--accent-emerald) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.badge-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-full);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-accent);
  margin-bottom: 1.25rem;
}

.pulse-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--accent-emerald);
  box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7); }
  70% { transform: scale(1); box-shadow: 0 0 0 8px rgba(16, 185, 129, 0); }
  100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 600;
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  border: 1px solid transparent;
  text-decoration: none;
  white-space: nowrap;
}

.btn-primary {
  background-color: var(--accent-tech);
  color: #FFFFFF;
  border-color: var(--accent-tech);
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.3);
}

.btn-primary:hover {
  background-color: #1D4ED8;
  text-decoration: none;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.4);
}

.btn-secondary {
  background-color: var(--bg-surface);
  color: var(--text-primary);
  border-color: var(--border-subtle);
}

.btn-secondary:hover {
  background-color: var(--bg-surface-elevated);
  border-color: var(--border-focus);
  text-decoration: none;
  transform: translateY(-1px);
}

.btn-ghost {
  background: transparent;
  color: var(--text-accent);
  padding: 0.65rem 0.85rem;
}

.btn-ghost:hover {
  background: var(--bg-surface);
  text-decoration: none;
}

.icon-btn {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  width: 38px;
  height: 38px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.icon-btn:hover {
  color: var(--text-primary);
  border-color: var(--border-focus);
  background-color: var(--bg-surface-elevated);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(15, 23, 42, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-subtle);
  transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

[data-theme="light"] .site-header {
  background-color: rgba(250, 250, 250, 0.88);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}

.brand-block {
  display: flex;
  flex-direction: column;
  text-decoration: none;
}

.brand-block:hover {
  text-decoration: none;
}

.brand-name {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: -0.02em;
}

.brand-highlight {
  color: var(--accent-tech-light);
}

.brand-subtitle {
  font-size: 0.6875rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.nav-item {
  color: var(--text-secondary);
  font-size: 0.875rem;
  font-weight: 500;
  transition: color var(--transition-fast);
}

.nav-item:hover {
  color: var(--text-primary);
  text-decoration: none;
}

.nav-btn-manifesto {
  background: transparent;
  border: none;
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--accent-tech-light);
  cursor: pointer;
  padding: 0;
  transition: color var(--transition-fast);
}

.nav-btn-manifesto:hover {
  color: var(--accent-emerald);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

[data-theme="dark"] .sun-icon { display: block; }
[data-theme="dark"] .moon-icon { display: none; }
[data-theme="light"] .sun-icon { display: none; }
[data-theme="light"] .moon-icon { display: block; }

.mobile-only {
  display: none;
}

.mobile-nav-panel {
  display: none;
  flex-direction: column;
  background-color: var(--bg-surface);
  border-bottom: 1px solid var(--border-subtle);
  padding: 1rem 1.5rem;
}

.mobile-nav-panel.open {
  display: flex;
}

.mobile-nav-item {
  padding: 0.75rem 0;
  font-size: 0.9375rem;
  color: var(--text-primary);
  border-bottom: 1px solid var(--border-subtle);
  text-decoration: none;
}

.mobile-manifesto-btn {
  background: none;
  border: none;
  text-align: left;
  font-family: var(--font-body);
  color: var(--accent-tech-light);
  cursor: pointer;
}

.hero-section {
  padding: 5rem 0 4rem;
  position: relative;
  z-index: 1;
}

.hero-container {
  max-width: 820px;
}

.hero-title {
  font-size: 3rem;
  line-height: 1.15;
  letter-spacing: -0.035em;
  margin-bottom: 1.5rem;
}

.hero-bio {
  font-size: 1.1875rem;
  line-height: 1.75;
  color: var(--text-secondary);
  margin-bottom: 1.75rem;
}

.hero-quote-box {
  border-left: 3px solid var(--accent-tech-light);
  background-color: var(--bg-surface);
  padding: 1.25rem 1.5rem;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin-bottom: 2.25rem;
}

.quote-text {
  font-family: var(--font-editorial);
  font-style: italic;
  font-size: 1rem;
  color: var(--text-primary);
  line-height: 1.6;
  margin-bottom: 0;
}

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  margin-bottom: 2rem;
}

.social-bar {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border-subtle);
}

.social-label {
  font-size: 0.75rem;
  font-family: var(--font-mono);
  color: var(--text-muted);
  text-transform: uppercase;
}

.social-link {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.8125rem;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
}

.social-link:hover {
  color: var(--accent-tech-light);
  text-decoration: none;
}

.avatar-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-subtle);
  text-align: center;
}

.avatar-wrapper {
  position: relative;
  margin-bottom: 1.25rem;
}

.avatar-img {
  width: 100%;
  max-width: 260px;
  height: auto;
  border-radius: var(--radius-md);
  display: block;
  margin: 0 auto;
}

.avatar-status-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background-color: var(--bg-primary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-full);
  padding: 0.3rem 0.75rem;
  font-size: 0.75rem;
  font-family: var(--font-mono);
  color: var(--text-secondary);
  margin-top: 0.75rem;
}

.status-indicator {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--accent-emerald);
}

.rigor-metrics {
  display: flex;
  align-items: center;
  justify-content: space-around;
  padding-top: 1rem;
  border-top: 1px solid var(--border-subtle);
}

.metric-item {
  display: flex;
  flex-direction: column;
}

.metric-val {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--accent-tech-light);
}

.metric-lbl {
  font-size: 0.6875rem;
  color: var(--text-muted);
  text-transform: uppercase;
}

.metric-divider {
  width: 1px;
  height: 28px;
  background-color: var(--border-subtle);
}

.section-block {
  padding: 4.5rem 0;
  border-top: 1px solid var(--border-subtle);
}

.section-alt {
  background-color: var(--bg-secondary);
}

.section-header {
  margin-bottom: 2.5rem;
}

.section-tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--accent-tech-light);
  font-weight: 600;
  text-transform: uppercase;
  margin-bottom: 0.5rem;
}

.section-title {
  font-size: 2rem;
  letter-spacing: -0.02em;
  margin-bottom: 0.5rem;
}

.section-desc {
  font-size: 1rem;
  color: var(--text-secondary);
  max-width: 680px;
}

.book-card-featured {
  display: grid;
  grid-template-columns: 340px 1fr;
  gap: 3rem;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-subtle);
  align-items: center;
}

.book-cover-col {
  text-align: center;
}

.book-cover-wrapper {
  display: inline-block;
  position: relative;
}

.book-cover-img {
  width: 100%;
  max-width: 320px;
  height: auto;
  border-radius: 6px;
  box-shadow: 0 20px 45px -10px rgba(0, 0, 0, 0.55), 0 2px 8px rgba(0, 0, 0, 0.3);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
  display: block;
}

[data-theme="light"] .book-cover-img {
  box-shadow: 0 20px 40px -10px rgba(0, 0, 0, 0.25), 0 2px 8px rgba(0, 0, 0, 0.1);
}

.book-card-featured:hover .book-cover-img {
  transform: translateY(-4px) scale(1.015);
  box-shadow: 0 28px 55px -10px rgba(0, 0, 0, 0.7), 0 4px 12px rgba(0, 0, 0, 0.4);
}

.book-meta-top {
  display: flex;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

.book-badge {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  background-color: var(--accent-tech);
  color: #FFFFFF;
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
}

.book-category {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  color: var(--text-muted);
  padding: 0.2rem 0;
  text-transform: uppercase;
}

.book-title {
  font-size: 2.125rem;
  margin-bottom: 0.35rem;
}

.book-subtitle {
  font-family: var(--font-editorial);
  font-size: 1.125rem;
  font-style: italic;
  font-weight: 400;
  color: var(--text-secondary);
  margin-bottom: 1.25rem;
}

.book-synopsis {
  font-size: 0.9375rem;
  line-height: 1.65;
  margin-bottom: 1.5rem;
}

.book-chapters-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin-bottom: 2rem;
}

.chapter-card {
  background-color: var(--bg-primary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 0.85rem;
}

.chapter-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  color: var(--accent-tech-light);
  font-weight: 600;
  margin-bottom: 0.2rem;
}

.chapter-name {
  display: block;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
}

.chapter-sub {
  font-size: 0.75rem;
  color: var(--text-muted);
  line-height: 1.35;
}

.book-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
}

.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5rem;
  margin-bottom: 2.5rem;
}

.skill-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all var(--transition-fast);
}

.skill-card:hover {
  border-color: var(--border-focus);
  transform: translateY(-2px);
  box-shadow: var(--shadow-subtle);
}

.skill-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 1rem;
}

.skill-icon-wrap {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-sm);
  background-color: var(--bg-primary);
  border: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: center;
}

.skill-meta-tags {
  display: flex;
  gap: 0.35rem;
}

.tag {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  padding: 0.15rem 0.5rem;
  border-radius: var(--radius-sm);
  font-weight: 500;
}

.tag-blue { background: rgba(37, 99, 235, 0.15); color: #60A5FA; }
.tag-cyan { background: rgba(56, 189, 248, 0.15); color: #38BDF8; }
.tag-emerald { background: rgba(16, 185, 129, 0.15); color: #34D399; }
.tag-amber { background: rgba(245, 158, 11, 0.15); color: #FBBF24; }
.tag-pink { background: rgba(236, 72, 153, 0.15); color: #F472B6; }

.skill-name {
  font-family: var(--font-mono);
  font-size: 0.9375rem;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.skill-desc {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  line-height: 1.55;
  margin-bottom: 1.25rem;
}

.skill-footer {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border-subtle);
}

.skill-action-btn {
  background: var(--bg-primary);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  font-size: 0.75rem;
  font-weight: 500;
  padding: 0.4rem 0.65rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  transition: all var(--transition-fast);
  text-decoration: none;
}

.skill-action-btn:hover {
  background-color: var(--bg-surface-elevated);
  color: var(--text-primary);
  border-color: var(--border-focus);
  text-decoration: none;
}

.skills-repo-banner {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1.5rem 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.repo-banner-text h4 {
  font-size: 1.125rem;
  margin-bottom: 0.25rem;
}

.repo-banner-text p {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.ventures-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.75rem;
}

.venture-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 2rem;
  display: flex;
  flex-direction: column;
  transition: all var(--transition-fast);
}

.venture-card:hover {
  border-color: var(--border-focus);
  transform: translateY(-2px);
}

.venture-status {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  color: var(--accent-emerald);
  font-weight: 600;
  letter-spacing: 0.05em;
  margin-bottom: 0.75rem;
}

.venture-name {
  font-size: 1.5rem;
  margin-bottom: 0.25rem;
}

.venture-tagline {
  font-family: var(--font-editorial);
  font-style: italic;
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.venture-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 1.5rem;
  flex-grow: 1;
}

.venture-tech-stack {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 1.25rem;
}

.venture-tech-stack span {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  background-color: var(--bg-primary);
  color: var(--text-secondary);
  padding: 0.2rem 0.55rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
}

.venture-link {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--accent-tech-light);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.essays-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.essay-item {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  display: grid;
  grid-template-columns: 140px 1fr auto;
  gap: 2rem;
  align-items: center;
  transition: all var(--transition-fast);
}

.essay-item:hover {
  border-color: var(--border-focus);
  background-color: var(--bg-surface-elevated);
}

.essay-meta {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.essay-date {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
}

.essay-readtime {
  font-size: 0.6875rem;
  color: var(--accent-emerald);
  font-weight: 600;
}

.essay-title {
  margin-bottom: 0.4rem;
}

.essay-link-btn {
  background: none;
  border: none;
  text-align: left;
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--text-primary);
  cursor: pointer;
  padding: 0;
  line-height: 1.35;
  transition: color var(--transition-fast);
}

.essay-link-btn:hover {
  color: var(--accent-tech-light);
}

.essay-excerpt {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.55;
}

.newsletter-card {
  background: linear-gradient(135deg, var(--bg-surface) 0%, var(--bg-surface-elevated) 100%);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-lg);
  padding: 3rem;
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 3rem;
  align-items: center;
}

.newsletter-tag {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  color: var(--accent-emerald);
  font-weight: 700;
  letter-spacing: 0.08em;
  margin-bottom: 0.5rem;
}

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

.newsletter-desc {
  font-size: 0.9375rem;
  line-height: 1.6;
}

.newsletter-form .form-group {
  display: flex;
  gap: 0.5rem;
}

.input-field {
  flex-grow: 1;
  background-color: var(--bg-primary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 0.75rem 1rem;
  font-family: var(--font-body);
  font-size: 0.875rem;
  color: var(--text-primary);
  outline: none;
  transition: border-color var(--transition-fast);
}

.input-field:focus {
  border-color: var(--accent-tech-light);
  box-shadow: 0 0 0 2px rgba(56, 189, 248, 0.2);
}

.form-feedback {
  font-size: 0.75rem;
  margin-top: 0.5rem;
  min-height: 1.2rem;
}

.form-feedback.success { color: var(--accent-emerald); }
.form-feedback.error { color: #EF4444; }

.contact-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 3.5rem;
  align-items: center;
}

.contact-methods {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 1.5rem;
}

.contact-item {
  display: flex;
  flex-direction: column;
}

.contact-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
}

.contact-val {
  font-size: 1.0625rem;
  font-weight: 600;
  color: var(--text-primary);
}

.highlight-domain {
  font-family: var(--font-mono);
  color: var(--accent-tech-light);
}

.contact-box-rigor {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 2rem;
}

.rigor-box-inner h4 {
  font-size: 1.125rem;
  margin-bottom: 0.75rem;
}

.rigor-box-inner p {
  font-family: var(--font-editorial);
  font-style: italic;
  font-size: 0.9375rem;
  line-height: 1.6;
  margin-bottom: 1.25rem;
}

.rigor-sign {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 1rem;
  border-top: 1px solid var(--border-subtle);
  font-size: 0.8125rem;
  font-weight: 600;
}

.badge-verif {
  font-family: var(--font-mono);
  font-size: 0.625rem;
  background-color: rgba(16, 185, 129, 0.15);
  color: var(--accent-emerald);
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
}

.site-footer {
  border-top: 1px solid var(--border-subtle);
  background-color: var(--bg-primary);
  padding: 2.5rem 0;
  font-size: 0.8125rem;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.footer-subtext {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

.footer-links {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.footer-links a, .footer-link-btn {
  color: var(--text-secondary);
  background: none;
  border: none;
  cursor: pointer;
  font-family: var(--font-body);
  font-size: 0.8125rem;
  transition: color var(--transition-fast);
}

.footer-links a:hover, .footer-link-btn:hover {
  color: var(--text-primary);
  text-decoration: none;
}

.custom-modal {
  border: none;
  background: transparent;
  max-width: 720px;
  width: 90%;
  margin: auto;
  padding: 0;
  color: var(--text-primary);
}

.custom-modal.wide-modal {
  max-width: 860px;
}

.custom-modal::backdrop {
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(8px);
}

.modal-content {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-elevated);
  display: flex;
  flex-direction: column;
  max-height: 85vh;
  overflow: hidden;
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  padding: 1.5rem 2rem;
  border-bottom: 1px solid var(--border-subtle);
}

.modal-tag {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  color: var(--accent-tech-light);
  font-weight: 700;
  letter-spacing: 0.05em;
  display: block;
  margin-bottom: 0.25rem;
}

.modal-title {
  font-size: 1.5rem;
}

.modal-close-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 1.75rem;
  cursor: pointer;
  line-height: 1;
  padding: 0.25rem;
  transition: color var(--transition-fast);
}

.modal-close-btn:hover {
  color: var(--text-primary);
}

.modal-body {
  padding: 2rem;
  overflow-y: auto;
}

.modal-footer {
  display: flex;
  justify-content: flex-end;
  gap: 0.75rem;
  padding: 1.25rem 2rem;
  border-top: 1px solid var(--border-subtle);
  background-color: var(--bg-primary);
}

.editorial-prose {
  font-family: var(--font-editorial);
  font-size: 1rem;
  line-height: 1.8;
  color: var(--text-primary);
}

.editorial-prose h3 {
  font-family: var(--font-display);
  font-size: 1.25rem;
  margin: 1.75rem 0 0.75rem;
}

.editorial-prose h4 {
  font-family: var(--font-display);
  font-size: 1.05rem;
  margin: 1.25rem 0 0.5rem;
}

.editorial-prose p {
  margin-bottom: 1.25rem;
  color: var(--text-primary);
}

.editorial-prose .lead-paragraph {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--accent-tech-light);
}

.math-callout {
  background-color: var(--bg-code);
  border: 1px solid var(--border-subtle);
  padding: 0.85rem 1.25rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--accent-emerald);
  margin-bottom: 1.25rem;
}

.skill-code-container {
  background-color: var(--bg-code);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.code-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.65rem 1rem;
  background-color: rgba(255, 255, 255, 0.03);
  border-bottom: 1px solid var(--border-subtle);
}

.code-lang {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  color: var(--text-muted);
  letter-spacing: 0.05em;
}

.btn-copy-code {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  font-size: 0.75rem;
  font-family: var(--font-body);
  padding: 0.3rem 0.6rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  transition: all var(--transition-fast);
}

.btn-copy-code:hover {
  color: var(--text-primary);
  border-color: var(--border-focus);
}

.code-block {
  display: block;
  padding: 1.25rem;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  line-height: 1.6;
  color: #E2E8F0;
  overflow-x: auto;
  white-space: pre-wrap;
  max-height: 480px;
}

.toast-container {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  z-index: 9999;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.toast {
  background-color: var(--bg-surface-elevated);
  border: 1px solid var(--accent-emerald);
  color: var(--text-primary);
  padding: 0.75rem 1.25rem;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  box-shadow: var(--shadow-elevated);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  animation: slideIn 0.25s ease-out;
}

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

@media (max-width: 900px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }

  .hero-title {
    font-size: 2.25rem;
  }

  .book-card-featured {
    grid-template-columns: 1fr;
    gap: 2rem;
    padding: 1.75rem;
  }

  .book-cover-img {
    max-width: 240px;
  }

  .book-chapters-grid {
    grid-template-columns: 1fr;
  }

  .newsletter-card {
    grid-template-columns: 1fr;
    gap: 1.75rem;
    padding: 2rem;
  }

  .contact-grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }

  .essay-item {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .essay-meta {
    flex-direction: row;
    gap: 1rem;
  }

  .skills-repo-banner {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 640px) {
  .nav-links {
    display: none;
  }

  .mobile-only {
    display: inline-flex;
  }

  .hero-title {
    font-size: 1.875rem;
  }

  .section-title {
    font-size: 1.65rem;
  }

  .newsletter-form .form-group {
    flex-direction: column;
  }
}