/* Eugene Shmorgun — site theme
   Tokens + components for the redesigned site. Replaces the old
   Skeleton-framework layout with a small hand-written system. */

:root {
  --ink: #1C1B17;
  --ink-soft: #55534B;
  --paper: #F7F5EF;
  --paper-2: #EFEBE0;
  --chip-bg: #E7EAE1;
  --line: #DEDACE;
  --accent: #24463A;
  --dark: #1C1B17;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: 'Source Sans 3', sans-serif;
  font-size: 16px;
  line-height: 1.5;
}

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

a { color: inherit; }

h1, h2, h3 {
  font-family: 'Fraunces', serif;
  font-weight: 600;
  margin: 0;
}

.wrap {
  max-width: 1120px;
  margin-inline: auto;
  padding-inline: clamp(20px, 5vw, 96px);
  box-sizing: border-box;
}

.eyebrow {
  display: block;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
}

/* Header / nav */
.site-header {
  border-bottom: 1px solid var(--line);
}

.site-header > .wrap {
  height: 88px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--ink);
}

.brand-mark {
  width: 38px;
  height: 38px;
  border-radius: 9px;
  background: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.brand-mark span {
  font-family: 'Fraunces', serif;
  font-weight: 600;
  font-size: 15px;
  color: var(--paper);
}

.brand-name {
  font-weight: 700;
  font-size: 16px;
  letter-spacing: 0.01em;
}

.nav-desktop {
  display: flex;
  align-items: center;
  gap: 36px;
}

.nav-link {
  font-size: 15px;
  color: var(--ink-soft);
  text-decoration: none;
}

.nav-link:hover, .nav-link.is-current { color: var(--ink); }

.lang-switch {
  display: flex;
  align-items: center;
  gap: 6px;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12px;
  color: var(--ink-soft);
}

.lang-switch a { text-decoration: none; color: var(--ink-soft); }
.lang-switch a.is-current { color: var(--accent); font-weight: 600; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  font-weight: 600;
  font-size: 15px;
  padding: 13px 26px;
  border-radius: 10px;
  box-sizing: border-box;
}

.btn-primary { background: var(--accent); color: var(--paper); border: 1.5px solid var(--accent); }
.btn-outline { background: transparent; color: var(--accent); border: 1.5px solid var(--accent); }
.btn-sm { padding: 9px 18px; font-size: 14px; border-radius: 8px; }

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border: none;
  background: transparent;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  padding: 0;
  flex-shrink: 0;
}

.nav-toggle svg line { stroke: var(--ink); }

.mobile-menu {
  display: none;
  border-bottom: 1px solid var(--line);
  background: var(--paper-2);
}

.mobile-menu.is-open { display: block; }

.mobile-menu .wrap {
  padding-block: 12px;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.mobile-menu a {
  font-size: 16px;
  font-weight: 600;
  color: var(--ink);
  text-decoration: none;
  padding: 12px 4px;
  min-height: 44px;
  display: flex;
  align-items: center;
}

.mobile-menu .lang-switch { padding: 12px 4px; font-size: 13px; }

/* Hero */
.hero .wrap {
  padding-block: clamp(48px, 8vw, 88px);
  display: grid;
  grid-template-columns: 420px 1fr;
  gap: 64px;
  align-items: center;
}

.hero-photo {
  border-radius: 20px;
  overflow: hidden;
  border: 1px solid var(--line);
  width: 100%;
}

.hero-photo img {
  width: 100%;
  aspect-ratio: 4 / 5;
  object-fit: cover;
  filter: grayscale(35%) contrast(1.05);
}

.hero-copy { display: flex; flex-direction: column; gap: 20px; }

.hero-copy h1 { font-size: clamp(38px, 5vw, 62px); line-height: 1.05; letter-spacing: -0.01em; }

.hero-copy p {
  margin: 0;
  max-width: 560px;
  font-size: 18px;
  line-height: 1.65;
  color: var(--ink-soft);
}

.chip-row { display: flex; flex-wrap: wrap; gap: 10px; }

.chip {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 13px;
  font-weight: 600;
  padding: 7px 14px;
  border-radius: 999px;
  background: var(--chip-bg);
  color: var(--accent);
}

.cta-row { display: flex; gap: 14px; margin-top: 6px; }

/* Divider */
.divider { height: 1px; background: var(--line); margin: 0 clamp(20px, 5vw, 96px); }

/* Sections */
.section { padding-block: clamp(48px, 7vw, 80px); }

.section-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 36px;
  gap: 20px;
}

.section-head h2 { font-size: clamp(26px, 3vw, 34px); }

.section-link { font-size: 15px; font-weight: 600; color: var(--accent); text-decoration: none; white-space: nowrap; }

.card-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 26px; }

.card {
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 28px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.card h3 { font-size: 20px; line-height: 1.35; flex-grow: 1; }

.card-cat {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
}

.card-link { font-size: 14px; font-weight: 600; color: var(--ink-soft); text-decoration: none; }
.card-link:hover { color: var(--ink); }

/* Plain content lists (articles bibliography, contacts, resume) */
.list-plain { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 22px; }

.list-plain li {
  padding-bottom: 22px;
  border-bottom: 1px solid var(--line);
  font-size: 16px;
  line-height: 1.6;
  color: var(--ink);
}

.list-plain li:last-child { border-bottom: none; padding-bottom: 0; }

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

.contact-list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; }

.contact-list li {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 22px 0;
  border-bottom: 1px solid var(--line);
  font-size: 17px;
}

.contact-list li:last-child { border-bottom: none; }

.contact-list .label {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-soft);
  width: 110px;
  flex-shrink: 0;
}

.contact-list a { color: var(--accent); text-decoration: none; }
.contact-list a:hover { text-decoration: underline; }

/* Contact band */
.contact-band { background: var(--dark); padding-block: clamp(40px, 6vw, 72px); }

.contact-band .wrap {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 32px;
  flex-wrap: wrap;
}

.contact-band .eyebrow { color: rgba(247,245,239,0.55); }

.contact-band h2 {
  margin-top: 10px;
  font-size: clamp(24px, 3vw, 32px);
  color: var(--paper);
  max-width: 480px;
}

.contact-band-links { display: flex; flex-direction: column; align-items: flex-end; gap: 12px; }

.contact-band-links .email { font-size: 19px; font-weight: 600; color: var(--paper); text-decoration: none; }

.contact-band-links .row { display: flex; gap: 22px; }
.contact-band-links a.secondary { font-size: 15px; color: rgba(247,245,239,0.75); text-decoration: none; }
.contact-band-links a.secondary:hover { color: var(--paper); }

/* Footer */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 26px 0;
}

.site-footer .wrap {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.site-footer .copyright {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 13px;
  color: var(--ink-soft);
}

/* Resume table */
.resume-entry { margin-bottom: 32px; }
.resume-entry:last-child { margin-bottom: 0; }

.resume-entry h3 {
  font-size: 20px;
  margin-bottom: 12px;
}

.resume-entry p { font-size: 16px; line-height: 1.6; color: var(--ink-soft); margin: 0 0 12px; }
.resume-entry a { color: var(--accent); }

.resume-entry ul { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 6px; }
.resume-entry ul li { font-size: 15px; color: var(--ink-soft); }
.resume-entry ul li strong { color: var(--ink); font-weight: 600; }

/* Page header (Articles / Contacts / Resume) */
.page-head { padding-block: clamp(40px, 6vw, 64px) 8px; }
.page-head h1 { font-size: clamp(32px, 4vw, 44px); }

/* Long-form article */
.article-head { padding-block: clamp(40px, 6vw, 64px) 12px; }
.article-head .wrap { max-width: 760px; }
.article-head .eyebrow { margin-bottom: 14px; }
.article-head h1 { font-size: clamp(30px, 4.2vw, 46px); line-height: 1.15; }
.article-dek { font-size: 18px; line-height: 1.6; color: var(--ink-soft); margin: 18px 0 0; }
.article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  margin-top: 22px;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 13px;
  color: var(--ink-soft);
}

.prose { max-width: 760px; margin-inline: auto; padding-block: 24px clamp(48px, 7vw, 80px); }
.prose h2 { font-size: clamp(24px, 2.6vw, 30px); line-height: 1.25; margin: 56px 0 18px; }
.prose h2:first-child { margin-top: 0; }
.prose h3 { font-size: clamp(19px, 2vw, 22px); line-height: 1.3; margin: 40px 0 14px; }
.prose p { font-size: 17px; line-height: 1.75; margin: 0 0 20px; }
.prose ul, .prose ol { margin: 0 0 20px; padding-left: 1.3em; font-size: 17px; line-height: 1.7; }
.prose li { margin-bottom: 8px; }
.prose li:last-child { margin-bottom: 0; }
.prose strong { font-weight: 600; }
.prose em { font-style: italic; color: var(--ink-soft); }
.prose a { color: var(--accent); text-decoration: underline; text-underline-offset: 2px; }
.prose blockquote {
  margin: 28px 0;
  padding: 2px 22px;
  border-left: 3px solid var(--accent);
  color: var(--ink-soft);
  font-style: italic;
}
.prose blockquote p:last-child { margin-bottom: 0; }
.prose code {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.85em;
  background: var(--paper-2);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 0.1em 0.4em;
}
.prose pre {
  background: var(--dark);
  color: #F1EFE7;
  border-radius: 10px;
  padding: 18px 20px;
  overflow-x: auto;
  margin: 24px 0;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 13.5px;
  line-height: 1.6;
}
.prose pre code { background: none; border: none; padding: 0; color: inherit; font-size: 1em; }
.prose figure { margin: 32px 0; }
.prose figure img, .prose figure video { border-radius: 10px; border: 1px solid var(--line); }
.prose figcaption { margin-top: 10px; font-size: 13.5px; color: var(--ink-soft); text-align: center; }
.prose .callout {
  background: var(--paper-2);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 18px 22px;
  margin: 28px 0;
  font-size: 15.5px;
  line-height: 1.65;
  color: var(--ink-soft);
}
.prose .callout strong { color: var(--ink); }
.prose hr { border: none; border-top: 1px solid var(--line); margin: 48px 0; }
.prose .formula { margin: 26px 0; font-size: 19px; overflow-x: auto; }
.prose .toc {
  background: var(--paper-2);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 20px 24px;
  margin: 8px 0 48px;
}
.prose .toc p.eyebrow { margin-bottom: 10px; }
.prose .toc ol { margin: 0; padding-left: 1.2em; font-size: 15px; line-height: 1.8; }
.article-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 760px;
  margin: 0 auto;
  padding-bottom: clamp(40px, 6vw, 64px);
}
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--accent);
  text-decoration: none;
}
.back-link:hover { text-decoration: underline; }

.share-row { display: flex; align-items: center; gap: 12px; }
.share-label {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink-soft);
  margin-right: 2px;
}
.share-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 8px;
  border: 1.5px solid var(--line);
  color: var(--ink-soft);
  background: transparent;
  padding: 0;
  cursor: pointer;
  transition: color .15s ease, border-color .15s ease;
}
.share-link:hover { color: var(--accent); border-color: var(--accent); }
.share-link svg { width: 16px; height: 16px; }
.share-copy .icon-check { display: none; }
.share-copy.is-copied .icon-link { display: none; }
.share-copy.is-copied .icon-check { display: block; }
.share-copy.is-copied { color: var(--accent); border-color: var(--accent); }

/* Responsive */
@media (max-width: 860px) {
  .hero .wrap { grid-template-columns: 1fr; gap: 32px; }
  .hero-photo { max-width: 420px; }
  .card-grid { grid-template-columns: 1fr; }
}

@media (max-width: 700px) {
  .nav-desktop { display: none; }
  .nav-toggle { display: flex; }
  .cta-row { flex-direction: column; }
  .cta-row .btn { width: 100%; }
  .contact-band .wrap { flex-direction: column; align-items: flex-start; }
  .contact-band-links { align-items: flex-start; }
  .site-footer .wrap { flex-direction: column; gap: 10px; text-align: center; }
  .contact-list li { flex-direction: column; gap: 4px; }
  .contact-list .label { width: auto; }
  .prose pre { font-size: 12.5px; padding: 14px 16px; }
  .prose p, .prose ul, .prose ol { font-size: 16px; }
}

/* Textbook card on the Articles page */
.card-textbook { max-width: 760px; }
.card-textbook h3 { flex-grow: 0; font-size: 24px; }
.card-textbook p { margin: 0; color: var(--ink-soft); line-height: 1.6; }
.card-links { display: flex; flex-wrap: wrap; gap: 8px 24px; }
.card-textbook + .card-textbook { margin-top: 26px; }