/* ============================================================
   lukasz.biz — programme management practice
   Strict design rules applied:
   - NO serif. NO italic display.
   - NO eyebrow kickers.
   - NO section numbers.
   - NO fabricated content — only verified LinkedIn facts.
   - One accent for action elements only.
   - Strong weight contrast, generous measure.
   ============================================================ */

:root{
  --ink:#0a0a0c;
  --ink-2:#3a3a3f;
  --ink-3:#6e6e75;
  --paper:#fafaf7;
  --paper-2:#f1f0ec;
  --line:rgba(10,10,12,.10);
  --line-strong:rgba(10,10,12,.20);
  --accent:#0b3a8a;
  --accent-ink:#fafaf7;
  --max:64rem;
  --max-text:42rem;
}

@media (prefers-color-scheme: dark){
  :root{
    --ink:#f3f3ef;
    --ink-2:#c5c5c0;
    --ink-3:#8a8a85;
    --paper:#0a0a0c;
    --paper-2:#15151a;
    --line:rgba(243,243,239,.10);
    --line-strong:rgba(243,243,239,.22);
    --accent:#6b9bff;
    --accent-ink:#0a0a0c;
  }
}

*,*::before,*::after{box-sizing:border-box}
html{font-size:100%;-webkit-text-size-adjust:100%;text-rendering:optimizeLegibility}
html,body{margin:0;padding:0}
img,svg,video{display:block;max-width:100%;height:auto}
body{
  font-family:"Inter",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;
  color:var(--ink);
  background:var(--paper);
  line-height:1.55;
  font-feature-settings:"cv11","ss01";
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
}
::selection{background:var(--accent);color:var(--accent-ink)}
::-moz-selection{background:var(--accent);color:var(--accent-ink)}

a{
  color:var(--ink);
  text-decoration:underline;
  text-decoration-color:var(--line-strong);
  text-underline-offset:.18em;
  text-decoration-thickness:.07em;
  transition:text-decoration-color .15s ease, color .15s ease;
}
a:hover{color:var(--accent);text-decoration-color:var(--accent)}

.skip{position:absolute;left:-9999px;top:auto;width:1px;height:1px;overflow:hidden}
.skip:focus{position:fixed;left:1rem;top:1rem;width:auto;height:auto;background:var(--ink);color:var(--paper);padding:.5rem .75rem;z-index:100;text-decoration:none}

/* ---------- masthead ---------- */
.masthead{
  border-bottom:1px solid var(--line);
  padding:1.25rem 1.5rem;
  background:var(--paper);
  position:sticky;top:0;z-index:10;
}
.masthead-row{
  max-width:var(--max);margin:0 auto;
  display:flex;align-items:center;justify-content:space-between;gap:2rem;
}
.brand{display:flex;flex-direction:column;gap:.1rem;text-decoration:none}
.brand:hover{text-decoration:none;color:var(--ink)}
.brand-name{
  font-weight:700;
  font-size:.9375rem;
  letter-spacing:-0.01em;
  color:var(--ink);
}
.brand-role{
  font-size:.75rem;
  font-weight:400;
  color:var(--ink-3);
}
.masthead-nav{
  display:flex;align-items:center;gap:1.75rem;
  font-size:.8125rem;
  font-weight:500;
}
.masthead-nav a{
  color:var(--ink-2);
  text-decoration:none;
  padding:.25rem 0;
}
.masthead-nav a:hover{color:var(--ink)}
@media (max-width:640px){
  .masthead-row{flex-direction:column;align-items:flex-start;gap:1rem}
  .masthead-nav{gap:1.25rem}
}

/* ---------- identity (hero) ---------- */
.identity{
  padding:6rem 1.5rem 5rem;
  border-bottom:1px solid var(--line);
}
.identity-inner{max-width:var(--max);margin:0 auto}
.identity-meta{
  font-size:.8125rem;
  font-weight:500;
  color:var(--ink-3);
  margin:0 0 2rem;
}
.identity-title{
  font-family:"Geist","Inter",sans-serif;
  font-weight:700;
  font-size:clamp(1.875rem,4vw,3.25rem);
  line-height:1.15;
  letter-spacing:-0.03em;
  margin:0 0 2rem;
  max-width:24ch;
  color:var(--ink);
}
.identity-summary{
  font-size:1.0625rem;
  line-height:1.6;
  color:var(--ink-2);
  max-width:var(--max-text);
  margin:0 0 2rem;
}
.identity-cta{
  display:flex;flex-wrap:wrap;align-items:center;gap:1rem;
}
.btn-primary,.btn-secondary{
  display:inline-flex;align-items:center;gap:.4rem;
  font-size:.9375rem;font-weight:500;
  padding:.75rem 1.1rem;
  text-decoration:none;
  border-radius:0;
  transition:background .15s ease, color .15s ease, border-color .15s ease;
  border:1px solid transparent;
}
.btn-primary{
  background:var(--accent);
  color:var(--accent-ink);
  border-color:var(--accent);
}
.btn-primary:hover{background:var(--ink);color:var(--paper);border-color:var(--ink)}
.btn-secondary{
  background:transparent;
  color:var(--ink);
  border-color:var(--line-strong);
}
.btn-secondary:hover{border-color:var(--ink)}

/* ---------- sections ---------- */
.section-inner{max-width:var(--max);margin:0 auto;padding:4rem 1.5rem}
.section-head{margin-bottom:2.5rem;max-width:var(--max-text)}
.section-title{
  font-family:"Geist","Inter",sans-serif;
  font-weight:700;
  font-size:clamp(1.625rem,2.8vw,2.25rem);
  letter-spacing:-0.025em;
  line-height:1.2;
  margin:0 0 .5rem;
  color:var(--ink);
}
.section-note{
  font-size:.9375rem;
  color:var(--ink-3);
  margin:0;
  max-width:48ch;
}

/* ---------- profile prose ---------- */
.profile-body{
  max-width:var(--max-text);
  font-size:1rem;
  line-height:1.7;
  color:var(--ink-2);
  border-top:1px solid var(--line);
  padding-top:2.5rem;
}
.profile-body p{margin:0 0 1.25rem}
.profile-body p:last-child{margin-bottom:0}

/* ---------- publications ---------- */
.books{
  list-style:none;margin:0;padding:0;
  display:flex;flex-direction:column;
  border-top:1px solid var(--line);
}
.book{
  padding:2.5rem 0;
  border-bottom:1px solid var(--line);
}
.book:last-child{border-bottom:none}
.book-meta{
  font-size:.75rem;
  font-weight:600;
  color:var(--ink-3);
  margin:0 0 .5rem;
  letter-spacing:.04em;
  text-transform:uppercase;
  display:flex;align-items:center;gap:.6rem;
}
.book-lang{
  font-weight:400;
  color:var(--ink-3);
}
.book-title{
  font-family:"Geist","Inter",sans-serif;
  font-weight:700;
  font-size:clamp(1.25rem,2vw,1.5rem);
  letter-spacing:-0.02em;
  line-height:1.25;
  margin:0 0 1rem;
  color:var(--ink);
  max-width:36ch;
}
.book-desc{
  font-size:.9375rem;
  line-height:1.65;
  color:var(--ink-2);
  margin:0 0 1.25rem;
  max-width:60ch;
}
.book-link{
  display:inline-flex;align-items:center;gap:.4rem;
  font-size:.8125rem;
  font-weight:500;
  color:var(--accent);
  text-decoration:none;
  padding-bottom:1px;
  border-bottom:1px solid currentColor;
}
.book-link:hover{border-bottom-color:var(--accent)}

/* ---------- languages ---------- */
.langs{
  display:grid;
  grid-template-columns:repeat(2,1fr);
  gap:1.5rem;
  margin:0;
  border-top:1px solid var(--line);
  padding-top:2.5rem;
  max-width:36rem;
}
@media (max-width:520px){.langs{grid-template-columns:1fr}}
.lang{margin:0;display:flex;flex-direction:column;gap:.25rem}
.lang-name{
  font-family:"Geist","Inter",sans-serif;
  font-weight:600;
  font-size:1rem;
  color:var(--ink);
}
.lang-level{
  font-size:.875rem;
  color:var(--ink-3);
  margin:0;
}

/* ---------- colophon ---------- */
.colophon{
  border-top:1px solid var(--line);
  padding:2rem 1.5rem 3rem;
  margin-top:2rem;
}
.colophon-inner{
  max-width:var(--max);margin:0 auto;
  display:flex;flex-wrap:wrap;justify-content:space-between;align-items:center;gap:.5rem 1rem;
}
.colophon-line{margin:0;font-size:.8125rem;color:var(--ink-3)}
.colophon-line a{color:var(--ink-2);text-decoration:none}
.colophon-line a:hover{color:var(--ink)}

/* ---------- responsive guards ---------- */
@media (max-width:520px){
  .identity{padding:4rem 1.25rem 3rem}
  .section-inner{padding:3rem 1.25rem}
  .identity-title{max-width:none;font-size:1.875rem;line-height:1.2}
  .identity-summary{font-size:1rem}
  .btn-primary,.btn-secondary{width:100%;justify-content:center}
}