/* Yevheniia Sakovets — site styles
   Reads as an engineer's record, not a landing page.
   Light and dark, high legibility, and it survives being printed in black and white. */

:root {
  color-scheme: light dark;

  --ink: #101c26;
  --ink-soft: #46596a;
  --ink-faint: #7d8f9c;
  --paper: #f6f7f8;
  --paper-raised: #ffffff;
  --paper-sunk: #eef0f2;
  --rule: #dfe4e8;
  --rule-strong: #c7d0d6;
  --signal: #0c6455;
  --signal-hover: #094b40;
  --signal-soft: #e3efec;

  --measure: 66ch;
  --gutter: clamp(1.25rem, 4vw, 3rem);
  --radius: 6px;

  --sans: "Archivo", ui-sans-serif, "Helvetica Neue", Arial, sans-serif;
  --serif: "Source Serif 4", Georgia, "Times New Roman", serif;

  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

@media (prefers-color-scheme: dark) {
  :root {
    --ink: #e8edf1;
    --ink-soft: #a7b6c1;
    --ink-faint: #7b8c98;
    --paper: #0e151b;
    --paper-raised: #151e26;
    --paper-sunk: #111a21;
    --rule: #26333d;
    --rule-strong: #35454f;
    --signal: #5fc9b0;
    --signal-hover: #8bdcc8;
    --signal-soft: #15302b;
  }
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 18px;
  line-height: 1.62;
  font-feature-settings: "onum" 1;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, nav, .meta, .record-year, .tag, .eyebrow,
.listing-title, .credential-name, .link-card-label {
  font-family: var(--sans);
  font-feature-settings: normal;
}

a {
  color: var(--signal);
  text-underline-offset: 0.18em;
  text-decoration-thickness: 0.06em;
  transition: color 0.15s var(--ease);
}
a:hover { color: var(--signal-hover); }
a:focus-visible {
  outline: 2px solid var(--signal);
  outline-offset: 3px;
  border-radius: 2px;
}

.wrap { max-width: 62rem; margin: 0 auto; padding: 0 var(--gutter); }
.prose { max-width: var(--measure); }

/* ---------- masthead ---------- */

.masthead {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid var(--ink);
  padding: 1.2rem 0 0.8rem;
  background: color-mix(in srgb, var(--paper) 90%, transparent);
  backdrop-filter: saturate(1.6) blur(12px);
  -webkit-backdrop-filter: saturate(1.6) blur(12px);
}
.masthead .wrap {
  max-width: 74rem;
  padding: 0 var(--gutter);
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem 1.75rem;
  align-items: flex-end;
  justify-content: space-between;
}
.masthead-brand {
  text-decoration: none;
  display: flex;
  flex-direction: column;
  gap: 0.12rem;
}
.masthead-name {
  font-family: var(--sans);
  font-weight: 600;
  font-size: 1.05rem;
  letter-spacing: -0.015em;
  color: var(--ink);
  line-height: 1.2;
}
.masthead-role {
  font-family: var(--sans);
  font-size: 0.76rem;
  letter-spacing: 0.04em;
  color: var(--ink-faint);
}
.masthead-brand:hover .masthead-name { color: var(--signal); }
.masthead nav { display: flex; gap: 1.6rem; }
.masthead nav a {
  text-decoration: none;
  color: var(--ink-soft);
  font-size: 0.82rem;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  padding-bottom: 0.1rem;
}
.masthead nav a:hover,
.masthead nav a[aria-current="page"] { color: var(--ink); }
.masthead nav a[aria-current="page"] { box-shadow: inset 0 -0.14em 0 var(--signal); }

@media (max-width: 40rem) {
  .masthead .wrap { align-items: flex-start; }
  .masthead nav { gap: 1.1rem; font-size: 0.78rem; }
}

/* ---------- hero ---------- */

.hero { padding: clamp(3rem, 8vw, 5.5rem) var(--gutter) clamp(2rem, 5vw, 3.25rem); }
.hero h1 {
  font-size: clamp(1.95rem, 4.4vw, 2.9rem);
  line-height: 1.08;
  letter-spacing: -0.03em;
  font-weight: 600;
  margin: 0 0 1.4rem;
  max-width: 24ch;
  text-wrap: balance;
}
.hero p {
  margin: 0 0 1rem;
  max-width: 56ch;
  font-size: clamp(1.05rem, 2vw, 1.28rem);
  line-height: 1.5;
  color: var(--ink-soft);
}
.hero p:last-child { margin-bottom: 0; }
.hero p.hero-breadth {
  font-size: clamp(0.98rem, 1.5vw, 1.05rem);
  color: var(--ink-faint);
  max-width: 60ch;
}
.hero-affiliation {
  font-family: var(--sans);
  font-size: 0.95rem;
  color: var(--ink-faint);
  margin: 1.6rem 0 0;
  line-height: 1.55;
}

.eyebrow {
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin: 0 0 1rem;
}

/* ---------- sections ---------- */

section { padding: clamp(2.75rem, 6vw, 4.25rem) 0; border-top: 1px solid var(--rule); }
section > .wrap > h2 {
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  margin: 0 0 1.75rem;
  color: var(--ink-faint);
}

/* ---------- link cards (resource rows) ---------- */

.link-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(14rem, 1fr));
  gap: 0.75rem;
  margin: 1.75rem 0 0;
  padding: 0;
  list-style: none;
}
.link-card {
  display: block;
  text-decoration: none;
  background: var(--paper-raised);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  padding: 0.95rem 1.1rem;
  transition: border-color 0.16s var(--ease), transform 0.16s var(--ease);
}
.link-card:hover {
  border-color: var(--signal);
  transform: translateY(-1px);
}
.link-card-label {
  display: block;
  font-size: 0.75rem;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-bottom: 0.3rem;
}
.link-card-value {
  display: block;
  font-family: var(--sans);
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--signal);
  word-break: break-word;
  font-variant-numeric: tabular-nums;
}
.link-card:hover .link-card-value { color: var(--signal-hover); }

/* ---------- record list (year + entry) ---------- */

.record { margin: 0; }
.record-item {
  display: grid;
  grid-template-columns: 5.5rem 1fr;
  gap: 0 1.5rem;
  padding: 1.4rem 0;
  border-top: 1px solid var(--rule);
}
.record-item:first-child { border-top: 0; padding-top: 0; }
.record-year {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--ink-faint);
  padding-top: 0.35rem;
  font-variant-numeric: tabular-nums;
}
.record-body { max-width: var(--measure); }
.record-body h3 {
  margin: 0 0 0.4rem;
  font-size: 1.12rem;
  font-weight: 600;
  line-height: 1.32;
  text-wrap: balance;
}
.record-body h3 a { text-decoration: none; color: var(--ink); }
.record-body h3 a:hover { color: var(--signal); text-decoration: underline; }
.record-body p { margin: 0; color: var(--ink-soft); font-size: 0.97rem; }
.tag {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--signal);
  background: var(--signal-soft);
  padding: 0.15rem 0.5rem;
  border-radius: 999px;
  margin-left: 0.55rem;
  vertical-align: 0.15em;
  white-space: nowrap;
}

@media (max-width: 34rem) {
  .record-item { grid-template-columns: 1fr; gap: 0.3rem; }
  .record-year { padding-top: 0; }
}

/* ---------- listing (recognition, credentials) ---------- */

.listing { margin: 0; padding: 0; list-style: none; max-width: var(--measure); }
.listing li {
  padding: 1rem 0;
  border-top: 1px solid var(--rule);
}
.listing li:first-child { border-top: 0; padding-top: 0; }
.listing-title {
  font-size: 1.02rem;
  font-weight: 600;
  line-height: 1.35;
  text-decoration: none;
  color: var(--ink);
  display: inline-flex;
  align-items: baseline;
  gap: 0.4rem;
}
a.listing-title:hover { color: var(--signal); }
a.listing-title::after {
  content: "\2197";
  font-size: 0.78em;
  color: var(--ink-faint);
  transition: transform 0.16s var(--ease), color 0.16s var(--ease);
}
a.listing-title:hover::after { color: var(--signal); transform: translate(1px, -1px); }
.listing .detail {
  display: block;
  font-size: 0.95rem;
  color: var(--ink-soft);
  margin-top: 0.25rem;
}
.credential-id {
  font-variant-numeric: tabular-nums;
  color: var(--ink-faint);
}

.two-col {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(18rem, 1fr));
  gap: clamp(1.75rem, 4vw, 3.5rem);
  align-items: start;
}
.two-col .listing { max-width: none; }
.two-col h3 {
  font-family: var(--sans);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin: 0 0 1.25rem;
}

/* ---------- document pages ---------- */

.doc-head { padding: clamp(3rem, 7vw, 5rem) var(--gutter) 2rem; max-width: 46rem; }
.doc-head h1 {
  font-size: clamp(2rem, 4.6vw, 3rem);
  line-height: 1.08;
  letter-spacing: -0.03em;
  font-weight: 600;
  margin: 0 0 1.1rem;
  max-width: 20ch;
  text-wrap: balance;
}
.doc-standfirst {
  font-size: clamp(1.08rem, 1.8vw, 1.22rem);
  color: var(--ink-soft);
  max-width: none;
  margin: 0 0 2.25rem;
  line-height: 1.52;
}

.meta {
  font-size: 0.9rem;
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  padding: 1.2rem 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(13rem, 1fr));
  gap: 0.95rem 2rem;
}
.meta div { display: flex; flex-direction: column; gap: 0.18rem; }
.meta dt {
  color: var(--ink-faint);
  font-size: 0.73rem;
  letter-spacing: 0.07em;
  text-transform: uppercase;
}
.meta dd { margin: 0; color: var(--ink); font-variant-numeric: tabular-nums; }

.toc {
  margin: 2.5rem 0 0;
  padding: 1.25rem 1.4rem;
  background: var(--paper-raised);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  max-width: none;
}
.toc ol {
  margin: 0.7rem 0 0;
  padding-left: 1.2rem;
  color: var(--ink-soft);
  columns: 2;
  column-gap: 2rem;
}
.toc li { margin-bottom: 0.35rem; break-inside: avoid; }
.toc a { text-decoration: none; }
.toc a:hover { text-decoration: underline; }
.toc h2 {
  font-size: 0.73rem;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  margin: 0;
  color: var(--ink-faint);
  font-weight: 600;
}
@media (max-width: 34rem) {
  .toc ol { columns: 1; }
}

.doc-body { padding: 1rem var(--gutter) 4rem; max-width: 46rem; }
.doc-body h2 {
  font-size: clamp(1.3rem, 2.4vw, 1.5rem);
  letter-spacing: -0.018em;
  font-weight: 600;
  margin: 3.25rem 0 0.9rem;
  scroll-margin-top: 5rem;
  text-wrap: balance;
}
.doc-body h3 { font-size: 1.1rem; font-weight: 600; margin: 2rem 0 0.6rem; }
.doc-body p, .doc-body li { max-width: none; }
.doc-body ul, .doc-body ol { padding-left: 1.3rem; }
.doc-body li { margin-bottom: 0.5rem; }
.doc-body figure { margin: 2rem 0; max-width: none; }
.doc-body figcaption { font-size: 0.9rem; color: var(--ink-faint); margin-top: 0.5rem; }

.doc-body table {
  border-collapse: collapse;
  width: 100%;
  max-width: none;
  font-size: 0.94rem;
  margin: 1.75rem 0;
  font-family: var(--sans);
}
.doc-body th, .doc-body td {
  text-align: left;
  padding: 0.6rem 0.85rem 0.6rem 0;
  border-bottom: 1px solid var(--rule);
  vertical-align: top;
}
.doc-body thead th {
  font-size: 0.73rem;
  font-weight: 600;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: var(--ink-faint);
  border-bottom-color: var(--rule-strong);
}
.doc-body tbody td:first-child {
  font-weight: 600;
  color: var(--signal);
  width: 3.5rem;
  font-variant-numeric: tabular-nums;
}
.doc-body tbody tr:last-child td { border-bottom: 0; }

.callout {
  background: var(--paper-raised);
  border: 1px solid var(--rule);
  border-left: 3px solid var(--signal);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 1.15rem 1.4rem;
  margin: 2rem 0;
  max-width: none;
  font-size: 0.97rem;
}
.callout p { margin: 0 0 0.6rem; }
.callout p:last-child { margin-bottom: 0; }

.cite {
  background: var(--paper-sunk);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  padding: 1.25rem 1.4rem;
  margin: 2.5rem 0 0;
  max-width: none;
  font-size: 0.92rem;
  line-height: 1.55;
}
.cite h2 {
  font-size: 0.73rem;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  margin: 0 0 0.7rem;
  color: var(--ink-faint);
}
.cite p { margin: 0; }

/* ---------- footer ---------- */

footer {
  border-top: 1px solid var(--rule);
  padding: 2.5rem 0 3.5rem;
  font-size: 0.88rem;
  color: var(--ink-faint);
  background: var(--paper-raised);
}
footer .wrap { display: flex; flex-wrap: wrap; gap: 0.6rem 2rem; justify-content: space-between; }
footer a { color: var(--ink-soft); }
footer a:hover { color: var(--signal); }

/* ---------- print ---------- */

@media print {
  :root {
    --ink: #000; --ink-soft: #222; --ink-faint: #444;
    --paper: #fff; --paper-raised: #fff; --paper-sunk: #fff;
    --rule: #bbb; --signal: #000;
  }
  body { font-size: 11.5pt; line-height: 1.45; }
  .masthead { position: static; backdrop-filter: none; }
  .masthead nav, .toc { display: none; }
  a { color: #000; text-decoration: underline; }
  .doc-body a[href^="http"]::after,
  .listing a[href^="http"]::after {
    content: " (" attr(href) ")";
    font-size: 9pt;
    color: #333;
    word-break: break-all;
  }
  a.listing-title::after { content: " (" attr(href) ")"; transform: none; }
  .link-card { border: 1px solid #bbb; }
  section, .doc-head { padding: 0.75rem 0; }
  h1, h2, h3 { page-break-after: avoid; }
  .meta, .cite, .callout, figure, table, .record-item, .listing li { page-break-inside: avoid; }
  footer { padding: 1rem 0; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
}

/* ---------- contact ---------- */

.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(18rem, 1fr));
  gap: clamp(1.75rem, 4vw, 3rem);
  align-items: start;
}
.contact-grid h3 {
  font-family: var(--sans);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin: 0 0 1rem;
}
.contact-grid p { margin: 0 0 1rem; max-width: 44ch; }
.contact-mail {
  font-family: var(--sans);
  font-size: 1.12rem;
  font-weight: 500;
  margin: 0 0 1rem;
}
.contact-mail a { text-decoration: none; }
.contact-mail a:hover { text-decoration: underline; }
.contact-note { font-size: 0.95rem; color: var(--ink-soft); }
.contact-links { list-style: none; margin: 0; padding: 0; }
.contact-links li {
  padding: 0.6rem 0;
  border-top: 1px solid var(--rule);
  font-family: var(--sans);
  font-size: 0.93rem;
}
.contact-links li:first-child { border-top: 0; padding-top: 0; }
.contact-links a {
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
}
.contact-links a:hover { text-decoration: underline; }
.contact-links .ico {
  flex: none;
  color: var(--ink-faint);
  transition: color 0.15s var(--ease);
}
.contact-links a:hover .ico { color: var(--signal); }