/* ============================================
   Roman Slinkov — .NET Backend Developer
   Design language: Ozon Tech / Ozon Bank inspired
   ============================================ */

@import url('https://fonts.googleapis.com/css2?family=Manrope:wght@500;700;800&family=Inter:wght@400;500;600&family=JetBrains+Mono:wght@400;500&display=swap');

:root{
  --bg: #070B14;
  --surface: #0E1526;
  --surface-2: #131C33;
  --surface-3: #182142;
  --border: rgba(255,255,255,0.08);
  --border-strong: rgba(255,255,255,0.16);

  --blue: #2B6BFF;
  --blue-bright: #4E86FF;
  --blue-soft: rgba(43,107,255,0.14);
  --raspberry: #FF2E63;
  --raspberry-soft: rgba(255,46,99,0.14);

  --text: #F3F5FA;
  --text-muted: #97A0B8;
  --text-dim: #616B87;

  --font-display: 'Manrope', 'Inter', sans-serif;
  --font-body: 'Inter', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  --radius-s: 10px;
  --radius-m: 16px;
  --radius-l: 24px;
  --container: 1120px;
}

*{ box-sizing: border-box; }
html{ scroll-behavior: smooth; }

body{
  margin:0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  position: relative;
  overflow-x: hidden;
}

/* ambient dotted grid, low-key nod to the Ozon Tech "scale & motion" pattern */
body::before{
  content:"";
  position: fixed;
  inset: 0;
  background-image: radial-gradient(circle, rgba(43,107,255,0.16) 1px, transparent 1px);
  background-size: 28px 28px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, black 0%, transparent 70%);
  pointer-events: none;
  z-index: 0;
}

@media (prefers-reduced-motion: reduce){
  html{ scroll-behavior: auto; }
  *{ animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; }
}

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

.container{
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 28px;
  position: relative;
  z-index: 1;
}

/* ---------------- eyebrow / labels ---------------- */
.eyebrow{
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--blue-bright);
  display: inline-flex;
  align-items: center;
  gap: 8px;
}
.eyebrow::before{
  content:"";
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--blue-bright);
  box-shadow: 0 0 0 3px var(--blue-soft);
}

/* ---------------- header / nav ---------------- */
.site-header{
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(7,11,20,0.78);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
}
.nav{
  display:flex;
  align-items:center;
  justify-content: space-between;
  padding: 16px 0;
}
.brand{
  display:flex;
  align-items:center;
  gap:12px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 16px;
  letter-spacing: -0.01em;
}
.brand-mark{
  width: 38px; height: 38px;
  border-radius: 50%;
  background: var(--surface-2);
  border: 1px solid var(--border-strong);
  display:flex; align-items:center; justify-content:center;
  position: relative;
}
.brand-mark svg{ width: 18px; height: 18px; }
.brand-sub{
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-weight: 400;
  font-size: 12px;
  display:block;
  margin-top: 2px;
  letter-spacing: 0.02em;
}
.brand-text{ display:flex; flex-direction:column; }

.nav-links{
  display:flex;
  align-items:center;
  gap: 4px;
  list-style:none;
  margin:0; padding:0;
}
.nav-links a{
  padding: 9px 16px;
  border-radius: 100px;
  font-size: 14.5px;
  font-weight: 500;
  color: var(--text-muted);
  transition: color .2s ease, background .2s ease;
}
.nav-links a:hover{ color: var(--text); background: var(--surface-2); }
.nav-links a.active{ color: var(--text); background: var(--surface-2); }

.nav-right{ display:flex; align-items:center; gap: 10px; }

.lang-toggle{
  width: 42px; height: 36px;
  border-radius: 100px;
  border: 1px solid var(--border-strong);
  background: var(--surface-2);
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 500;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition: border-color .2s ease, background .2s ease;
}
.lang-toggle:hover{ border-color: var(--blue-bright); background: var(--surface-3); }

.nav-cta{
  display:inline-flex;
  align-items:center;
  gap: 8px;
  padding: 9px 18px;
  border-radius: 100px;
  background: var(--blue);
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  transition: background .2s ease, transform .2s ease;
}
.nav-cta:hover{ background: var(--blue-bright); transform: translateY(-1px); }

.nav-burger{ display:none; }

/* ---------------- buttons ---------------- */
.btn{
  display:inline-flex;
  align-items:center;
  gap: 9px;
  padding: 13px 24px;
  border-radius: 100px;
  font-size: 15px;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform .2s ease, background .2s ease, border-color .2s ease;
}
.btn-primary{ background: var(--blue); color: #fff; }
.btn-primary:hover{ background: var(--blue-bright); transform: translateY(-2px); }
.btn-ghost{ background: transparent; color: var(--text); border-color: var(--border-strong); }
.btn-ghost:hover{ border-color: var(--blue-bright); color: var(--blue-bright); transform: translateY(-2px); }
.btn svg{ width:16px; height:16px; }

/* ---------------- hero ---------------- */
.hero{
  padding: 84px 0 72px;
  position: relative;
}
.hero-grid{
  display:grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 56px;
  align-items:center;
}
.hero-kicker{ margin-bottom: 22px; }
.hero h1{
  font-family: var(--font-display);
  font-size: clamp(38px, 5vw, 60px);
  line-height: 1.04;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin: 0 0 20px;
}
.hero h1 .accent{
  background: linear-gradient(100deg, var(--blue-bright), var(--raspberry) 120%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero p.lead{
  font-size: 18px;
  color: var(--text-muted);
  max-width: 520px;
  margin: 0 0 34px;
}
.hero-actions{ display:flex; gap: 14px; flex-wrap: wrap; margin-bottom: 44px; }

.hero-stats{
  display:grid;
  grid-template-columns: repeat(3, auto);
  gap: 30px;
}
.stat-num{
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 26px;
  color: var(--text);
}
.stat-label{
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-top: 4px;
}

/* hero portrait + orbit signature */
.hero-portrait{
  position: relative;
  width: 100%;
  max-width: 380px;
  margin: 0 auto;
  aspect-ratio: 1/1;
  display:flex; align-items:center; justify-content:center;
}
.portrait-frame{
  position: relative;
  width: 82%;
  height: 82%;
  border-radius: 50%;
  overflow: hidden;
  border: 1px solid var(--border-strong);
  box-shadow: 0 30px 80px -20px rgba(43,107,255,0.35);
}
.portrait-frame img{
  width: 100%; height: 100%;
  object-fit: cover;
  object-position: center 22%;
  filter: saturate(0.92) contrast(1.03);
}
.orbit-ring{
  position: absolute;
  inset: 0;
  border-radius: 50%;
  border: 1px dashed var(--border-strong);
  animation: spin 22s linear infinite;
}
.orbit-ring::before{
  content:"";
  position: absolute;
  top: -5px;
  left: 50%;
  transform: translateX(-50%);
  width: 10px; height: 10px;
  border-radius: 50%;
  background: var(--blue-bright);
  box-shadow: 0 0 0 5px var(--blue-soft);
}
@keyframes spin{ to{ transform: rotate(360deg); } }

.status-pill{
  position: absolute;
  bottom: 4%;
  left: 50%;
  transform: translateX(-50%);
  display:flex;
  align-items:center;
  gap: 8px;
  padding: 8px 16px;
  border-radius: 100px;
  background: var(--surface-2);
  border: 1px solid var(--border-strong);
  font-family: var(--font-mono);
  font-size: 12px;
  white-space: nowrap;
  box-shadow: 0 10px 30px -10px rgba(0,0,0,0.6);
}
.status-pill .dot{
  width: 7px; height:7px; border-radius: 50%;
  background: #34D399;
  box-shadow: 0 0 0 3px rgba(52,211,153,0.22);
}

/* ---------------- sections ---------------- */
section{ padding: 88px 0; position: relative; }
.section-head{ margin-bottom: 48px; max-width: 640px; }
.section-head h2{
  font-family: var(--font-display);
  font-size: clamp(28px, 3.4vw, 38px);
  font-weight: 800;
  letter-spacing: -0.01em;
  margin: 14px 0 12px;
}
.section-head p{ color: var(--text-muted); font-size: 16px; margin:0; }

.divider{
  border: none;
  border-top: 1px solid var(--border);
  margin: 0;
}

/* ---------------- cards ---------------- */
.card{
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-m);
  padding: 28px;
  transition: border-color .25s ease, transform .25s ease, background .25s ease;
}
.card:hover{ border-color: var(--border-strong); transform: translateY(-3px); background: var(--surface-2); }

.grid-3{ display:grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.grid-2{ display:grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }

/* skills */
.skill-group-title{
  font-family: var(--font-mono);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--blue-bright);
  margin: 0 0 14px;
}
.tag-row{ display:flex; flex-wrap: wrap; gap: 8px; }
.tag{
  font-family: var(--font-mono);
  font-size: 12.5px;
  padding: 7px 13px;
  border-radius: 8px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text-muted);
}

/* ---------------- timeline (experience) ---------------- */
.timeline{
  position: relative;
  padding-left: 36px;
  border-left: 1px solid var(--border);
}
.timeline-item{
  position: relative;
  padding-bottom: 56px;
}
.timeline-item:last-child{ padding-bottom: 0; }
.timeline-item::before{
  content:"";
  position: absolute;
  left: -42px;
  top: 4px;
  width: 13px; height: 13px;
  border-radius: 50%;
  background: var(--bg);
  border: 2px solid var(--blue-bright);
  box-shadow: 0 0 0 5px rgba(43,107,255,0.12);
}
.timeline-date{
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 8px;
}
.timeline-item h3{
  font-family: var(--font-display);
  font-size: 21px;
  font-weight: 800;
  margin: 0 0 2px;
}
.timeline-role{
  color: var(--blue-bright);
  font-weight: 600;
  font-size: 14.5px;
  margin-bottom: 16px;
}
.timeline-item ul{
  margin: 0 0 16px;
  padding-left: 20px;
  color: var(--text-muted);
}
.timeline-item li{ margin-bottom: 8px; }
.timeline-result{
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-s);
  padding: 16px 18px;
  font-size: 14.5px;
  color: var(--text-muted);
}
.timeline-result strong{ color: var(--text); }

/* ---------------- education ---------------- */
.edu-item{ display:flex; gap: 18px; }
.edu-year{
  font-family: var(--font-mono);
  color: var(--blue-bright);
  font-size: 13px;
  min-width: 52px;
  padding-top: 3px;
}
.edu-item h4{ margin: 0 0 4px; font-family: var(--font-display); font-size: 16.5px; }
.edu-item p{ margin:0; color: var(--text-muted); font-size: 14.5px; }

/* ---------------- projects ---------------- */
.project-card{
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-l);
  padding: 32px;
  display:flex;
  flex-direction: column;
  height: 100%;
}
.project-card .proj-badge{
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--raspberry);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 14px;
}
.project-card h3{
  font-family: var(--font-display);
  font-size: 22px;
  margin: 0 0 10px;
}
.project-card p.desc{ color: var(--text-muted); font-size: 15px; margin: 0 0 20px; flex-grow:1; }
.project-card .tag-row{ margin-bottom: 22px; }
.project-link{
  display:inline-flex; align-items:center; gap: 8px;
  font-weight: 600; font-size: 14.5px; color: var(--blue-bright);
}
.project-link svg{ width:15px; height:15px; transition: transform .2s ease; }
.project-card:hover .project-link svg{ transform: translate(3px,-3px); }

.gh-card{
  background: linear-gradient(155deg, var(--surface-3), var(--surface));
  border: 1px solid var(--border-strong);
}

/* ---------------- contacts ---------------- */
.contact-grid{ display:grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.contact-card{
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-m);
  padding: 30px 26px;
  text-align: left;
  transition: border-color .25s ease, transform .25s ease;
}
.contact-card:hover{ border-color: var(--blue-bright); transform: translateY(-4px); }
.contact-icon{
  width: 44px; height: 44px;
  border-radius: 12px;
  background: var(--blue-soft);
  display:flex; align-items:center; justify-content:center;
  margin-bottom: 18px;
}
.contact-icon svg{ width: 20px; height: 20px; color: var(--blue-bright); }
.contact-card h3{ font-family: var(--font-display); font-size: 17px; margin: 0 0 6px; }
.contact-card p{ margin:0; color: var(--text-muted); font-size: 14.5px; word-break: break-word; }

.info-strip{
  display:flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 40px;
}
.info-chip{
  display:flex; align-items:center; gap: 8px;
  padding: 10px 16px;
  border-radius: 100px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  font-size: 13.5px;
  color: var(--text-muted);
}
.info-chip svg{ width:14px; height:14px; color: var(--blue-bright); }

/* ---------------- CTA band ---------------- */
.cta-band{
  border-radius: var(--radius-l);
  background: radial-gradient(120% 140% at 15% 0%, rgba(43,107,255,0.22), transparent 60%), var(--surface);
  border: 1px solid var(--border-strong);
  padding: 56px;
  display:flex;
  align-items:center;
  justify-content: space-between;
  gap: 32px;
  flex-wrap: wrap;
}
.cta-band h2{ font-family: var(--font-display); font-size: 28px; margin: 0 0 8px; }
.cta-band p{ color: var(--text-muted); margin:0; max-width: 460px; }
.cta-actions{ display:flex; gap: 12px; flex-wrap: wrap; }

/* ---------------- footer ---------------- */
.site-footer{
  border-top: 1px solid var(--border);
  padding: 40px 0;
  margin-top: 40px;
}
.footer-inner{
  display:flex; align-items:center; justify-content: space-between; flex-wrap: wrap; gap: 16px;
}
.footer-inner p{ margin:0; color: var(--text-dim); font-size: 13.5px; font-family: var(--font-mono); }
.footer-links{ display:flex; gap: 18px; }
.footer-links a{ color: var(--text-muted); font-size: 13.5px; transition: color .2s ease; }
.footer-links a:hover{ color: var(--blue-bright); }

/* ---------------- page hero (sub pages) ---------------- */
.page-hero{ padding: 64px 0 20px; }
.page-hero .eyebrow{ margin-bottom: 18px; }
.page-hero h1{
  font-family: var(--font-display);
  font-size: clamp(32px, 4.4vw, 48px);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin: 0 0 16px;
}
.page-hero p{ color: var(--text-muted); font-size: 17px; max-width: 620px; margin: 0; }

/* ---------------- reveal on scroll ---------------- */
.reveal{ opacity: 0; transform: translateY(16px); transition: opacity .6s ease, transform .6s ease; }
.reveal.is-visible{ opacity: 1; transform: none; }

/* ---------------- case study (featured project) ---------------- */
.case-study{
  background: var(--surface);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-l);
  padding: 44px;
  position: relative;
  overflow: hidden;
}
.case-study::before{
  content:"";
  position: absolute;
  top: -120px; right: -120px;
  width: 320px; height: 320px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(43,107,255,0.22), transparent 70%);
  pointer-events: none;
}
.case-top{
  display:flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 24px;
  margin-bottom: 22px;
  position: relative;
  z-index: 1;
}
.case-top .timeline-date{ margin-bottom: 10px; }
.case-top h3{
  font-family: var(--font-display);
  font-size: 26px;
  font-weight: 800;
  margin: 0 0 4px;
}
.case-top .case-subtitle{
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-dim);
}
.case-role{
  color: var(--blue-bright);
  font-weight: 600;
  font-size: 14.5px;
}
.case-intro{
  color: var(--text-muted);
  font-size: 15.5px;
  max-width: 720px;
  margin: 0 0 26px;
  position: relative;
  z-index: 1;
}
.case-intro strong{ color: var(--text); }

.case-stats{
  display:grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin-bottom: 32px;
  position: relative;
  z-index: 1;
}
.case-stat{
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-s);
  padding: 16px 14px;
  text-align: center;
}
.case-stat .num{
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 22px;
  color: var(--text);
  display:block;
}
.case-stat .lbl{
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-top: 4px;
}

.case-sub-title{
  font-family: var(--font-mono);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--blue-bright);
  margin: 0 0 16px;
}

/* FSM diagram */
.fsm-wrap{
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-m);
  padding: 24px;
  margin-bottom: 32px;
  overflow-x: auto;
}
.fsm-wrap svg{ display:block; margin: 0 auto; min-width: 640px; }
.fsm-note{
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-dim);
  margin-top: 14px;
  text-align: center;
}

/* architecture layers */
.layer-row{
  display:grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin-bottom: 32px;
  position: relative;
  z-index: 1;
}
.layer-card{
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-s);
  padding: 16px;
}
.layer-card .layer-index{
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--raspberry);
  margin-bottom: 8px;
}
.layer-card h4{
  font-family: var(--font-display);
  font-size: 15px;
  margin: 0 0 6px;
}
.layer-card p{
  font-size: 12.5px;
  color: var(--text-muted);
  margin: 0;
  line-height: 1.5;
}

.case-highlights{
  display:grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-bottom: 32px;
  position: relative;
  z-index: 1;
}
.case-highlight{
  display:flex;
  gap: 12px;
  align-items: flex-start;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-s);
  padding: 14px 16px;
}
.case-highlight svg{ width:16px; height:16px; color: var(--blue-bright); margin-top:2px; flex-shrink:0; }
.case-highlight span{ font-size: 13.5px; color: var(--text-muted); }

.case-footer{
  display:flex;
  align-items:center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  position: relative;
  z-index: 1;
  padding-top: 22px;
  border-top: 1px solid var(--border);
}

/* compact secondary role card */
.role-compact{
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-m);
  padding: 28px;
  margin-top: 24px;
}

/* ---------------- responsive ---------------- */
@media (max-width: 900px){
  .hero-grid{ grid-template-columns: 1fr; }
  .hero-portrait{ order:-1; max-width: 280px; }
  .grid-3{ grid-template-columns: 1fr 1fr; }
  .contact-grid{ grid-template-columns: 1fr; }
  .cta-band{ padding: 36px; }
  .case-stats{ grid-template-columns: repeat(2, 1fr); }
  .layer-row{ grid-template-columns: repeat(2, 1fr); }
  .case-highlights{ grid-template-columns: 1fr; }
  .case-study{ padding: 30px; }
}
@media (max-width: 720px){
  .nav-links{
    position: fixed;
    top: 68px; left: 16px; right: 16px;
    background: var(--surface);
    border: 1px solid var(--border-strong);
    border-radius: var(--radius-m);
    flex-direction: column;
    align-items: stretch;
    padding: 10px;
    display: none;
    gap: 2px;
    box-shadow: 0 20px 50px -20px rgba(0,0,0,0.7);
  }
  .nav-links.open{ display:flex; }
  .nav-links a{ padding: 12px 16px; }
  .nav-burger{
    display:flex; align-items:center; justify-content:center;
    width: 40px; height:36px;
    border-radius: 10px;
    border: 1px solid var(--border-strong);
    background: var(--surface-2);
    cursor:pointer;
  }
  .nav-burger svg{ width:18px; height:18px; }
  .grid-3{ grid-template-columns: 1fr; }
  .hero-stats{ grid-template-columns: repeat(3,1fr); gap: 16px; }
  .stat-num{ font-size: 21px; }
  .cta-band{ flex-direction: column; align-items: flex-start; }
  .case-stats{ grid-template-columns: repeat(2, 1fr); }
  .layer-row{ grid-template-columns: 1fr 1fr; }
}