/* =========================================================================
   Vadim Seliukov - personal site
   Clean minimal / light · editorial · one accent
   ========================================================================= */

@import url('https://fonts.googleapis.com/css2?family=Fraunces:opsz,wght@9..144,400;9..144,500;9..144,600&family=Inter:wght@400;500;600&family=JetBrains+Mono:wght@400;500&display=swap');

/* ---------- tokens ---------- */
:root {
  --bg:        #FAFAF8;
  --surface:   #FFFFFF;
  --ink:       #0B0B0F;
  --ink-2:     #34343A;
  --muted:     #6A6A73;
  --line:      #E6E6E1;
  --line-2:    #D9D9D3;
  --accent:    #2657E6;
  --accent-dk: #1B3FAF;
  --accent-wash:#EEF2FE;

  --serif: "Fraunces", Georgia, "Times New Roman", serif;
  --sans:  "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --mono:  "JetBrains Mono", ui-monospace, "SFMono-Regular", Menlo, monospace;

  --maxw: 1080px;
  --pad: clamp(1.25rem, 5vw, 2.5rem);
  --section-y: clamp(4.5rem, 10vw, 8rem);

  --radius: 14px;
  --radius-sm: 10px;

  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --dur: 240ms;

  --z-nav: 50;
}

/* ---------- reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; }
}

body {
  font-family: var(--sans);
  font-size: 1.0625rem;
  line-height: 1.65;
  color: var(--ink-2);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; }

::selection { background: var(--accent); color: #fff; }

/* ---------- layout ---------- */
.container { width: 100%; max-width: var(--maxw); margin-inline: auto; padding-inline: var(--pad); }
.section { padding-block: var(--section-y); border-top: 1px solid var(--line); }
.section:first-of-type { border-top: 0; }

.skip-link {
  position: absolute; left: -999px; top: 0; z-index: 100;
  background: var(--ink); color: #fff; padding: .7rem 1rem; border-radius: 0 0 8px 0;
}
.skip-link:focus { left: 0; }

/* ---------- typography ---------- */
h1, h2, h3 { color: var(--ink); font-weight: 500; line-height: 1.1; letter-spacing: -0.01em; }
.eyebrow {
  font-family: var(--mono);
  font-size: .74rem;
  font-weight: 500;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--accent-dk);
  display: inline-flex; align-items: center; gap: .55rem;
}
.eyebrow::before {
  content: ""; width: 26px; height: 1px; background: var(--accent); display: inline-block;
}
.section-head { display: flex; align-items: baseline; gap: 1rem; margin-bottom: clamp(2rem, 5vw, 3.25rem); }
.section-num { font-family: var(--mono); font-size: .8rem; color: var(--muted); flex: none; padding-top: .35rem; }
.section-title { font-family: var(--serif); font-size: clamp(1.7rem, 3.4vw, 2.4rem); font-weight: 500; }
.lead { font-size: clamp(1.05rem, 2vw, 1.2rem); color: var(--ink-2); max-width: 60ch; }
.muted { color: var(--muted); }
.mono { font-family: var(--mono); }

/* ---------- nav ---------- */
.nav {
  position: sticky; top: 0; z-index: var(--z-nav);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}
.nav[data-scrolled="true"] { border-bottom-color: var(--line); }
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand { font-family: var(--serif); font-weight: 600; font-size: 1.15rem; color: var(--ink); letter-spacing: -.02em; display: inline-flex; align-items: center; gap: .5rem; }
.brand .dot { width: 7px; height: 7px; border-radius: 50%; background: var(--accent); display: inline-block; }
.nav-links { display: flex; align-items: center; gap: 2rem; }
.nav-links a { font-size: .92rem; color: var(--ink-2); position: relative; transition: color var(--dur) var(--ease); }
.nav-links a::after {
  content: ""; position: absolute; left: 0; bottom: -4px; height: 1.5px; width: 0; background: var(--accent);
  transition: width var(--dur) var(--ease);
}
.nav-links a:hover, .nav-links a[aria-current="true"] { color: var(--ink); }
.nav-links a:hover::after, .nav-links a[aria-current="true"]::after { width: 100%; }
.nav-cta {
  display: inline-flex; align-items: center; gap: .5rem;
  font-size: .88rem; font-weight: 500; color: var(--ink);
  padding: .5rem .9rem; border: 1px solid var(--line-2); border-radius: 999px;
  white-space: nowrap;
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease), color var(--dur) var(--ease);
}
.nav-cta svg { width: 15px; height: 15px; flex: none; }
.nav-cta:hover { background: var(--accent-wash); color: var(--accent-dk); border-color: var(--accent); }
.nav-toggle { display: none; width: 44px; height: 44px; border: 1px solid var(--line-2); border-radius: 10px; background: var(--surface); align-items: center; justify-content: center; }
.nav-toggle svg { width: 20px; height: 20px; }

@media (max-width: 760px) {
  .nav-links { display: none; }
  .nav-toggle { display: inline-flex; }
  .nav[data-open="true"] .nav-links {
    display: flex; position: absolute; top: 64px; left: 0; right: 0;
    flex-direction: column; align-items: flex-start; gap: 1rem;
    background: var(--surface); border-bottom: 1px solid var(--line);
    padding: 1.25rem var(--pad) 1.75rem;
  }
  .nav[data-open="true"] .nav-links a { font-size: 1.05rem; }
}

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: .55rem;
  font-size: .95rem; font-weight: 500; line-height: 1;
  padding: .85rem 1.3rem; border-radius: 999px; border: 1px solid transparent;
  transition: transform var(--dur) var(--ease), background var(--dur) var(--ease), border-color var(--dur) var(--ease), color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
  white-space: nowrap;
}
.btn svg { width: 17px; height: 17px; }
.btn-primary { background: var(--ink); color: #fff; }
.btn-primary:hover { background: var(--accent); box-shadow: 0 8px 24px -10px color-mix(in srgb, var(--accent) 70%, transparent); }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--line-2); }
.btn-ghost:hover { border-color: var(--ink); background: var(--surface); }
.icon-link {
  display: inline-flex; align-items: center; justify-content: center;
  width: 44px; height: 44px; border-radius: 50%; border: 1px solid var(--line-2);
  color: var(--ink-2); transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}
.icon-link svg { width: 19px; height: 19px; }
.icon-link:hover { color: var(--ink); border-color: var(--ink); background: var(--surface); }

/* ---------- hero ---------- */
.hero { padding-top: clamp(3.5rem, 8vw, 6rem); padding-bottom: clamp(3rem, 7vw, 5rem); }
.hero .eyebrow { margin-bottom: 1.5rem; }
.hero h1 {
  font-family: var(--serif);
  font-size: clamp(2.5rem, 6.4vw, 4.7rem);
  font-weight: 400;
  line-height: 1.04;
  letter-spacing: -0.02em;
  max-width: 17ch;
  margin-bottom: 1.6rem;
}
.hero h1 em { font-style: italic; color: var(--accent-dk); }
.hero-sub { font-size: clamp(1.05rem, 2vw, 1.2rem); color: var(--ink-2); max-width: 56ch; margin-bottom: 2.2rem; }
.hero-sub strong { color: var(--ink); font-weight: 600; }
.hero-actions { display: flex; flex-wrap: wrap; align-items: center; gap: .8rem; margin-bottom: 2.75rem; }
.hero-facts {
  display: flex; flex-wrap: wrap; gap: .55rem .5rem; align-items: center;
  font-family: var(--mono); font-size: .8rem; color: var(--muted);
}
.hero-facts span { display: inline-flex; align-items: center; }
.hero-facts span:not(:last-child)::after { content: "/"; margin-left: .5rem; color: var(--line-2); }

.now-line {
  margin-top: 2.5rem; padding: 1rem 1.15rem; border: 1px solid var(--line);
  border-radius: var(--radius-sm); background: var(--surface);
  display: flex; align-items: center; gap: .75rem; font-size: .95rem; color: var(--ink-2);
  max-width: 60ch;
}
.now-line .pulse { width: 8px; height: 8px; border-radius: 50%; background: #16a34a; flex: none; position: relative; }
.now-line .pulse::after { content: ""; position: absolute; inset: -5px; border-radius: 50%; border: 1px solid #16a34a; opacity: .5; animation: pulse 2.4s var(--ease) infinite; }
.now-line a { color: var(--accent-dk); font-weight: 500; border-bottom: 1px solid color-mix(in srgb, var(--accent) 40%, transparent); }
@keyframes pulse { 0% { transform: scale(1); opacity: .5; } 70% { transform: scale(2.1); opacity: 0; } 100% { opacity: 0; } }

/* ---------- about ---------- */
.about-grid { display: grid; grid-template-columns: 1.4fr 1fr; gap: clamp(2rem, 5vw, 4.5rem); align-items: start; }
.about-body p { margin-bottom: 1.15rem; max-width: 62ch; }
.about-body p:last-child { margin-bottom: 0; }
.about-body strong { color: var(--ink); font-weight: 600; }
.about-aside { position: sticky; top: 96px; display: flex; flex-direction: column; gap: 1.5rem; }
.fact-list { display: flex; flex-direction: column; gap: 0; border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; background: var(--surface); }
.fact-list div { display: flex; justify-content: space-between; gap: 1rem; padding: .85rem 1.1rem; border-top: 1px solid var(--line); font-size: .9rem; }
.fact-list div:first-child { border-top: 0; }
.fact-list dt { color: var(--muted); font-family: var(--mono); font-size: .78rem; letter-spacing: .03em; }
.fact-list dd { color: var(--ink); text-align: right; font-weight: 500; }
@media (max-width: 820px) { .about-grid { grid-template-columns: 1fr; } .about-aside { position: static; } }

/* ---------- skills ---------- */
.skills-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1px; background: var(--line); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.skill-card { background: var(--surface); padding: clamp(1.4rem, 3vw, 1.9rem); transition: background var(--dur) var(--ease); }
.skill-card:hover { background: color-mix(in srgb, var(--accent-wash) 55%, var(--surface)); }
.skill-card h3 { font-family: var(--sans); font-size: 1.02rem; font-weight: 600; margin-bottom: .35rem; display: flex; align-items: center; gap: .6rem; }
.skill-card h3 .k { font-family: var(--mono); font-size: .72rem; color: var(--accent-dk); font-weight: 500; }
.skill-card p { font-size: .92rem; color: var(--muted); margin-bottom: 1rem; }
.tag-row { display: flex; flex-wrap: wrap; gap: .4rem; }
.tag { font-family: var(--mono); font-size: .76rem; color: var(--ink-2); background: var(--bg); border: 1px solid var(--line-2); border-radius: 7px; padding: .28rem .55rem; }
@media (max-width: 720px) { .skills-grid { grid-template-columns: 1fr; } }

/* ---------- experience ---------- */
.xp { display: grid; grid-template-columns: 200px 1fr; gap: clamp(1.5rem, 4vw, 3rem); }
.xp + .xp { margin-top: clamp(2.5rem, 5vw, 3.5rem); padding-top: clamp(2.5rem, 5vw, 3.5rem); border-top: 1px solid var(--line); }
.xp-meta .role-co { font-family: var(--mono); font-size: .82rem; color: var(--accent-dk); font-weight: 500; }
.xp-meta .dates { font-family: var(--mono); font-size: .82rem; color: var(--muted); margin-top: .3rem; }
.xp-meta .place { font-size: .85rem; color: var(--muted); margin-top: .3rem; }
.xp-body h3 { font-family: var(--serif); font-size: 1.45rem; font-weight: 500; margin-bottom: .2rem; }
.xp-body .subtitle { color: var(--ink-2); font-size: .98rem; margin-bottom: 1.1rem; }
.xp-list { list-style: none; padding: 0; display: flex; flex-direction: column; gap: .7rem; }
.xp-list li { position: relative; padding-left: 1.4rem; color: var(--ink-2); font-size: .98rem; }
.xp-list li::before { content: ""; position: absolute; left: 0; top: .62em; width: 6px; height: 6px; border-radius: 50%; background: var(--accent); }
.xp-list li strong { color: var(--ink); font-weight: 600; }
@media (max-width: 720px) { .xp { grid-template-columns: 1fr; gap: .9rem; } }

/* ---------- projects ---------- */
.projects { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1.25rem; }
.project { grid-column: span 1; display: flex; flex-direction: column; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: clamp(1.5rem, 3vw, 2rem); transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease); }
.project:hover { border-color: var(--line-2); transform: translateY(-3px); box-shadow: 0 18px 40px -28px rgba(11,11,15,.35); }
.project.featured { grid-column: span 2; display: grid; grid-template-columns: 1.1fr 1fr; gap: clamp(1.5rem, 4vw, 3rem); align-items: center; }
.project-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 1rem; margin-bottom: .9rem; }
.project-kicker { font-family: var(--mono); font-size: .74rem; letter-spacing: .1em; text-transform: uppercase; color: var(--muted); }
.project h3 { font-family: var(--serif); font-size: clamp(1.4rem, 3vw, 1.9rem); font-weight: 500; margin: .25rem 0 .1rem; }
.project h3 a { display: inline-flex; align-items: center; gap: .45rem; }
.project h3 a:hover { color: var(--accent-dk); }
.project h3 svg { width: 18px; height: 18px; color: var(--muted); transition: transform var(--dur) var(--ease), color var(--dur) var(--ease); }
.project h3 a:hover svg { color: var(--accent-dk); transform: translate(2px, -2px); }
.project p { font-size: .96rem; color: var(--ink-2); margin-bottom: 1.1rem; }
.project .stack { margin-top: auto; }
.status-chip { display: inline-flex; align-items: center; gap: .4rem; font-family: var(--mono); font-size: .72rem; color: var(--ink-2); border: 1px solid var(--line-2); border-radius: 999px; padding: .2rem .6rem; }
.status-chip .d { width: 6px; height: 6px; border-radius: 50%; background: var(--accent); }
.status-chip.live .d { background: #16a34a; }
@media (max-width: 760px) { .projects { grid-template-columns: 1fr; } .project.featured { grid-column: span 1; grid-template-columns: 1fr; } }

/* ---------- education ---------- */
.edu { display: flex; flex-direction: column; gap: 0; }
.edu-row { display: grid; grid-template-columns: 200px 1fr auto; gap: 1.5rem; padding: 1.3rem 0; border-top: 1px solid var(--line); align-items: baseline; }
.edu-row:first-child { border-top: 0; }
.edu-row .dates { font-family: var(--mono); font-size: .82rem; color: var(--muted); }
.edu-row h3 { font-size: 1.08rem; font-weight: 600; }
.edu-row .school { color: var(--ink-2); font-size: .95rem; margin-top: .2rem; }
.edu-row .degree-tag { font-family: var(--mono); font-size: .74rem; color: var(--accent-dk); white-space: nowrap; }
@media (max-width: 720px) { .edu-row { grid-template-columns: 1fr; gap: .3rem; } .edu-row .degree-tag { order: -1; } }

/* ---------- testimonials ---------- */
.quotes { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1.25rem; }
.quote { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: clamp(1.5rem, 3vw, 2rem); display: flex; flex-direction: column; gap: 1.1rem; }
.quote blockquote { font-family: var(--serif); font-size: 1.12rem; line-height: 1.5; color: var(--ink); }
.quote .attr { display: flex; align-items: center; gap: .8rem; margin-top: auto; }
.quote .avatar { width: 40px; height: 40px; border-radius: 50%; background: var(--accent-wash); color: var(--accent-dk); display: grid; place-items: center; font-family: var(--mono); font-weight: 500; font-size: .9rem; flex: none; }
.quote .who { font-size: .9rem; }
.quote .who strong { display: block; color: var(--ink); font-weight: 600; }
.quote .who span { color: var(--muted); }
.quote[data-placeholder] { border-style: dashed; }
.quote[data-placeholder] blockquote { color: var(--muted); font-style: italic; }
@media (max-width: 720px) { .quotes { grid-template-columns: 1fr; } }

/* ---------- contact ---------- */
.contact-grid { display: grid; grid-template-columns: 1fr 1.1fr; gap: clamp(2rem, 5vw, 4rem); align-items: start; }
.contact-intro h2 { font-family: var(--serif); font-size: clamp(1.9rem, 4vw, 2.8rem); font-weight: 500; margin-bottom: 1rem; }
.contact-intro p { color: var(--ink-2); max-width: 42ch; margin-bottom: 2rem; }
.contact-methods { display: flex; flex-direction: column; gap: .9rem; }
.contact-methods a { display: inline-flex; align-items: center; gap: .7rem; color: var(--ink-2); font-size: .98rem; transition: color var(--dur) var(--ease); }
.contact-methods a:hover { color: var(--accent-dk); }
.contact-methods a svg { width: 18px; height: 18px; color: var(--muted); }
form { display: flex; flex-direction: column; gap: 1.1rem; }
.field { display: flex; flex-direction: column; gap: .45rem; }
.field label { font-size: .85rem; font-weight: 500; color: var(--ink); }
.field input, .field textarea {
  font: inherit; font-size: .98rem; color: var(--ink);
  background: var(--surface); border: 1px solid var(--line-2); border-radius: var(--radius-sm);
  padding: .8rem .9rem; transition: border-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}
.field input::placeholder, .field textarea::placeholder { color: #A6A6AE; }
.field input:focus, .field textarea:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-wash); }
.field textarea { resize: vertical; min-height: 120px; }
.hp { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }
.form-foot { display: flex; align-items: center; gap: 1rem; flex-wrap: wrap; }
.form-status { font-size: .9rem; }
.form-consent { font-size: .8rem; line-height: 1.5; color: var(--muted); margin-top: -.2rem; }
.form-consent a { color: var(--accent-dk); border-bottom: 1px solid color-mix(in srgb, var(--accent) 30%, transparent); }
.form-status[data-state="error"] { color: #b91c1c; }
.form-status[data-state="ok"] { color: #15803d; }
.btn[aria-busy="true"] { opacity: .7; pointer-events: none; }
@media (max-width: 820px) { .contact-grid { grid-template-columns: 1fr; } }

/* focus visibility */
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 4px; }

/* ---------- footer ---------- */
.footer { border-top: 1px solid var(--line); padding-block: 2.5rem; }
.footer-inner { display: flex; align-items: center; justify-content: space-between; gap: 1rem; flex-wrap: wrap; }
.footer .brand { font-size: 1rem; }
.footer-meta { font-family: var(--mono); font-size: .78rem; color: var(--muted); }
.footer-legal { margin-top: 1.5rem; padding-top: 1.25rem; border-top: 1px solid var(--line); font-size: .74rem; line-height: 1.5; color: var(--muted); max-width: 70ch; }
.footer-social { display: flex; gap: .6rem; }
.footer-social a { width: 38px; height: 38px; }

/* ---------- reveal animation ---------- */
[data-reveal] { opacity: 0; transform: translateY(16px); transition: opacity 620ms var(--ease), transform 620ms var(--ease); }
[data-reveal].is-in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) { [data-reveal] { opacity: 1; transform: none; } }