/* =========================================================
   Konashkov Engineering — corporate site
   Light, technical, restrained.
   ========================================================= */

:root {
  --bg: #ffffff;
  --bg-soft: #f6f8fb;
  --bg-mute: #eef2f7;
  --border: #e3e8ee;
  --border-strong: #cdd6e0;
  --text: #0a2540;
  --text-soft: #4a5b70;
  --text-mute: #7d8b9f;
  --primary: #0a2540;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --success: #10b981;
  --code-bg: #0a2540;
  --code-text: #e6edf6;

  --container: 1180px;
  --radius-s: 6px;
  --radius:   10px;
  --radius-l: 16px;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
               "Helvetica Neue", Arial, "Inter", system-ui, sans-serif;
  --font-mono: "SFMono-Regular", ui-monospace, Menlo, Consolas,
               "Liberation Mono", monospace;

  --shadow-s: 0 1px 2px rgba(10, 37, 64, 0.06);
  --shadow:   0 4px 16px rgba(10, 37, 64, 0.08);
  --shadow-l: 0 12px 40px rgba(10, 37, 64, 0.12);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.55;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color .15s ease;
}
a:hover { color: var(--accent-hover); }

img, svg { max-width: 100%; display: block; }

h1, h2, h3, h4 {
  color: var(--primary);
  line-height: 1.2;
  letter-spacing: -0.01em;
  margin: 0 0 .5em;
}
h1 { font-size: clamp(2rem, 4vw, 3rem); font-weight: 700; letter-spacing: -0.02em; }
h2 { font-size: clamp(1.6rem, 3vw, 2.2rem); font-weight: 700; }
h3 { font-size: 1.25rem; font-weight: 600; }
h4 { font-size: 1rem; font-weight: 600; }

p { margin: 0 0 1em; color: var(--text-soft); }
.lead { font-size: 1.15rem; color: var(--text-soft); max-width: 680px; }

code {
  font-family: var(--font-mono);
  font-size: .9em;
  background: var(--bg-mute);
  padding: 2px 6px;
  border-radius: var(--radius-s);
  color: var(--primary);
}

/* ============== Layout primitives ============== */

.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

section {
  padding: 80px 0;
  border-bottom: 1px solid var(--border);
}
section:last-of-type { border-bottom: none; }

.section-soft { background: var(--bg-soft); }

.section-head { max-width: 720px; margin-bottom: 48px; }
.section-head .eyebrow {
  display: inline-block;
  font-size: .8rem;
  font-weight: 600;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 12px;
}
.section-head h2 { margin-bottom: 12px; }
.section-head p { font-size: 1.1rem; color: var(--text-soft); margin: 0; }

.grid { display: grid; gap: 24px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

@media (max-width: 900px) {
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  section { padding: 56px 0; }
}

/* ============== Buttons ============== */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 22px;
  font-size: .95rem;
  font-weight: 600;
  border-radius: var(--radius);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all .18s ease;
  white-space: nowrap;
}
.btn-primary {
  background: var(--primary);
  color: #fff;
}
.btn-primary:hover {
  background: #082035;
  color: #fff;
  transform: translateY(-1px);
  box-shadow: var(--shadow);
}
.btn-secondary {
  background: #fff;
  color: var(--primary);
  border-color: var(--border-strong);
}
.btn-secondary:hover {
  border-color: var(--primary);
  color: var(--primary);
}
.btn-ghost {
  background: transparent;
  color: var(--accent);
  padding: 8px 0;
}
.btn-ghost:hover { color: var(--accent-hover); }
.btn .arrow { transition: transform .15s ease; }
.btn:hover .arrow { transform: translateX(2px); }

/* ============== Header / Nav ============== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, .85);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--primary);
  font-weight: 700;
  letter-spacing: -0.01em;
  font-size: 1.05rem;
}
.brand:hover { color: var(--primary); }
.brand-mark {
  width: 28px; height: 28px;
  border-radius: 7px;
  background: var(--primary);
  color: #fff;
  display: grid; place-items: center;
  font-family: var(--font-mono);
  font-size: .85rem;
  font-weight: 700;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
  margin: 0;
  padding: 0;
}
.nav-links a {
  color: var(--text-soft);
  font-size: .95rem;
  font-weight: 500;
}
.nav-links a:hover, .nav-links a.active { color: var(--primary); }

.nav-right { display: flex; align-items: center; gap: 16px; }

.lang-switcher {
  display: flex;
  border: 1px solid var(--border);
  border-radius: var(--radius-s);
  overflow: hidden;
  font-size: .8rem;
  font-weight: 600;
}
.lang-switcher a {
  padding: 6px 10px;
  color: var(--text-mute);
  border-right: 1px solid var(--border);
}
.lang-switcher a:last-child { border-right: none; }
.lang-switcher a.active {
  background: var(--primary);
  color: #fff;
}
.lang-switcher a:hover:not(.active) {
  background: var(--bg-mute);
  color: var(--primary);
}

.burger {
  display: none;
  background: none;
  border: 1px solid var(--border);
  border-radius: var(--radius-s);
  padding: 8px;
  cursor: pointer;
}
.burger span { display: block; width: 18px; height: 2px; background: var(--primary); margin: 3px 0; }

@media (max-width: 820px) {
  .nav-links {
    position: absolute;
    top: 68px; left: 0; right: 0;
    flex-direction: column;
    gap: 0;
    background: #fff;
    border-bottom: 1px solid var(--border);
    padding: 12px 24px 20px;
    display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links li { width: 100%; padding: 10px 0; border-bottom: 1px solid var(--border); }
  .nav-links li:last-child { border-bottom: none; }
  .burger { display: block; }
}

/* ============== Hero ============== */

.hero {
  padding: 96px 0 80px;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  top: -120px; right: -120px;
  width: 520px; height: 520px;
  background: radial-gradient(circle at center, rgba(37, 99, 235, .08), transparent 60%);
  pointer-events: none;
}
.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr .9fr;
  gap: 48px;
  align-items: center;
}
@media (max-width: 900px) {
  .hero-grid { grid-template-columns: 1fr; }
  .hero { padding: 56px 0 48px; }
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  background: var(--bg-mute);
  border: 1px solid var(--border);
  border-radius: 999px;
  font-size: .82rem;
  font-weight: 500;
  color: var(--text-soft);
  margin-bottom: 24px;
}
.hero-badge .dot {
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--success);
  box-shadow: 0 0 0 4px rgba(16, 185, 129, .15);
}
.hero h1 { margin-bottom: 20px; }
.hero p.lead { font-size: 1.2rem; margin-bottom: 32px; }
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; }

/* Hero diagram */
.hero-diagram {
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius-l);
  padding: 24px;
  font-family: var(--font-mono);
  font-size: .82rem;
  color: var(--text-soft);
  box-shadow: var(--shadow);
}
.hero-diagram .row {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 0;
  border-bottom: 1px dashed var(--border);
}
.hero-diagram .row:last-child { border-bottom: none; }
.hero-diagram .pill {
  display: inline-block;
  padding: 3px 8px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-s);
  color: var(--primary);
  font-weight: 600;
}
.hero-diagram .ok { color: var(--success); font-weight: 700; }

/* ============== Stats strip ============== */

.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  padding: 48px 0;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.stats .stat .num {
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--primary);
  letter-spacing: -0.02em;
  font-feature-settings: "tnum";
}
.stats .stat .lbl {
  color: var(--text-mute);
  font-size: .9rem;
}
@media (max-width: 700px) {
  .stats { grid-template-columns: repeat(2, 1fr); }
}

/* ============== Cards ============== */

.card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  transition: border-color .15s ease, transform .15s ease, box-shadow .15s ease;
}
.card:hover {
  border-color: var(--border-strong);
  box-shadow: var(--shadow);
  transform: translateY(-2px);
}
.card .icon {
  width: 40px; height: 40px;
  border-radius: 10px;
  background: var(--bg-mute);
  color: var(--accent);
  display: grid; place-items: center;
  margin-bottom: 16px;
}
.card h3 { margin-bottom: 8px; }
.card p { margin: 0; }
.card ul {
  margin: 12px 0 0; padding: 0; list-style: none;
}
.card ul li {
  padding: 4px 0;
  font-size: .92rem;
  color: var(--text-soft);
  position: relative;
  padding-left: 18px;
}
.card ul li::before {
  content: "";
  position: absolute;
  left: 0; top: 12px;
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--accent);
}

/* ============== Case cards ============== */

.case {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-l);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: all .15s ease;
}
.case:hover { box-shadow: var(--shadow-l); transform: translateY(-2px); }
.case-head {
  padding: 24px 28px 0;
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
}
.case-head .industry {
  font-size: .78rem;
  font-weight: 600;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--accent);
}
.case-head .scale {
  font-family: var(--font-mono);
  font-size: .82rem;
  color: var(--text-mute);
  background: var(--bg-mute);
  padding: 4px 10px;
  border-radius: 999px;
}
.case-body { padding: 12px 28px 24px; flex: 1; }
.case-body h3 { font-size: 1.2rem; margin-bottom: 12px; }
.case-body p { font-size: .95rem; margin-bottom: 12px; }

.case-metrics {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  padding: 20px 28px;
  background: var(--bg-soft);
  border-top: 1px solid var(--border);
}
.case-metrics .m .v {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--primary);
  font-feature-settings: "tnum";
  letter-spacing: -0.01em;
  line-height: 1.1;
}
.case-metrics .m .l {
  font-size: .78rem;
  color: var(--text-mute);
  margin-top: 2px;
}
.case-tags {
  display: flex; flex-wrap: wrap; gap: 6px;
  padding: 0 28px 20px;
}
.case-tags span {
  font-family: var(--font-mono);
  font-size: .75rem;
  padding: 3px 8px;
  background: var(--bg-mute);
  border-radius: var(--radius-s);
  color: var(--text-soft);
}

/* ============== Tech logos / strip ============== */

.tech-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 24px;
  padding: 24px 0;
  align-items: center;
  justify-content: center;
}
.tech-strip span {
  font-family: var(--font-mono);
  color: var(--text-mute);
  font-size: .9rem;
  padding: 6px 14px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: #fff;
}

/* ============== Process steps ============== */

.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  counter-reset: step;
}
.steps .step {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  position: relative;
}
.steps .step::before {
  counter-increment: step;
  content: "0" counter(step);
  position: absolute;
  top: 16px; right: 20px;
  font-family: var(--font-mono);
  font-size: .9rem;
  color: var(--text-mute);
}
.steps .step h4 { margin-bottom: 8px; }
.steps .step p { margin: 0; font-size: .9rem; }
@media (max-width: 900px) { .steps { grid-template-columns: 1fr; } }

/* ============== CTA banner ============== */

.cta-banner {
  background: var(--primary);
  color: #fff;
  border-radius: var(--radius-l);
  padding: 56px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 32px;
}
.cta-banner h2 { color: #fff; margin-bottom: 8px; }
.cta-banner p { color: rgba(255,255,255,.75); margin: 0; }
.cta-banner .btn-primary {
  background: #fff; color: var(--primary);
}
.cta-banner .btn-primary:hover { background: #f0f4f9; color: var(--primary); }
@media (max-width: 700px) {
  .cta-banner { flex-direction: column; align-items: flex-start; padding: 32px; }
}

/* ============== Footer ============== */

.site-footer {
  background: var(--bg-soft);
  border-top: 1px solid var(--border);
  padding: 56px 0 32px;
  color: var(--text-soft);
  font-size: .92rem;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}
@media (max-width: 800px) { .footer-grid { grid-template-columns: 1fr 1fr; } }
.footer-grid h4 { font-size: .85rem; text-transform: uppercase; letter-spacing: .08em; color: var(--text-mute); margin-bottom: 16px; font-weight: 600; }
.footer-grid ul { list-style: none; padding: 0; margin: 0; }
.footer-grid ul li { margin-bottom: 8px; }
.footer-grid ul a { color: var(--text-soft); }
.footer-grid ul a:hover { color: var(--primary); }
.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  color: var(--text-mute);
  font-size: .85rem;
}
.footer-social { display: flex; gap: 12px; }
.footer-social a {
  width: 32px; height: 32px;
  border: 1px solid var(--border-strong);
  border-radius: 8px;
  display: grid; place-items: center;
  color: var(--text-soft);
  background: #fff;
}
.footer-social a:hover { color: var(--primary); border-color: var(--primary); }

/* ============== Inner page hero ============== */

.page-hero {
  padding: 80px 0 56px;
  background: var(--bg-soft);
  border-bottom: 1px solid var(--border);
}
.page-hero .eyebrow {
  font-size: .8rem;
  font-weight: 600;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 12px;
  display: inline-block;
}
.page-hero h1 { margin-bottom: 16px; }
.page-hero p { font-size: 1.15rem; max-width: 720px; }

/* ============== Service detail blocks ============== */

.service-block {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: 56px;
  padding: 56px 0;
  border-bottom: 1px solid var(--border);
}
.service-block:last-child { border-bottom: none; }
@media (max-width: 900px) {
  .service-block { grid-template-columns: 1fr; gap: 24px; padding: 40px 0; }
}
.service-block .num {
  font-family: var(--font-mono);
  font-size: .9rem;
  color: var(--text-mute);
  margin-bottom: 8px;
}
.service-block h2 { font-size: 1.7rem; margin-bottom: 16px; }
.service-block .feature-list {
  list-style: none; padding: 0; margin: 0;
  display: grid;
  gap: 16px;
}
.service-block .feature-list li {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 22px;
  display: flex;
  gap: 14px;
  align-items: flex-start;
}
.service-block .feature-list strong {
  color: var(--primary);
  display: block;
  margin-bottom: 4px;
}
.service-block .feature-list span {
  color: var(--text-soft);
  font-size: .92rem;
}
.service-block .check {
  flex-shrink: 0;
  width: 22px; height: 22px;
  border-radius: 50%;
  background: rgba(16, 185, 129, .12);
  color: var(--success);
  display: grid; place-items: center;
  margin-top: 2px;
}

/* ============== About / team ============== */

.team-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
@media (max-width: 900px) { .team-grid { grid-template-columns: 1fr; } }
.team-member {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
}
.team-member .avatar {
  width: 56px; height: 56px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--primary));
  color: #fff;
  display: grid; place-items: center;
  font-weight: 700;
  margin-bottom: 16px;
  font-size: 1.1rem;
}
.team-member .role {
  color: var(--accent);
  font-size: .85rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.value-list {
  list-style: none; padding: 0; margin: 0;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}
@media (max-width: 700px) { .value-list { grid-template-columns: 1fr; } }
.value-list li { padding-left: 36px; position: relative; }
.value-list li::before {
  content: "→";
  position: absolute;
  left: 0; top: 0;
  font-family: var(--font-mono);
  color: var(--accent);
  font-weight: 700;
}
.value-list strong { display: block; color: var(--primary); margin-bottom: 4px; font-size: 1.05rem; }
.value-list span { color: var(--text-soft); font-size: .95rem; }

/* ============== Contact form ============== */

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 48px;
  align-items: start;
}
@media (max-width: 900px) { .contact-grid { grid-template-columns: 1fr; } }
.contact-info h3 { margin-bottom: 8px; }
.contact-info .item {
  display: flex; gap: 14px;
  padding: 14px 0;
  border-bottom: 1px solid var(--border);
}
.contact-info .item:last-child { border-bottom: none; }
.contact-info .item .lbl { color: var(--text-mute); font-size: .85rem; min-width: 90px; }
.contact-info .item .v a { color: var(--primary); font-weight: 500; }

form.contact {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
}
form.contact label {
  display: block;
  font-size: .85rem;
  font-weight: 600;
  color: var(--text-soft);
  margin-bottom: 6px;
}
form.contact input, form.contact textarea {
  width: 100%;
  padding: 11px 14px;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-s);
  font-family: inherit;
  font-size: .95rem;
  margin-bottom: 16px;
  background: #fff;
  color: var(--text);
  transition: border-color .15s ease, box-shadow .15s ease;
}
form.contact textarea { min-height: 120px; resize: vertical; }
form.contact input:focus, form.contact textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, .15);
}

/* ============== Misc ============== */

.section-head.center { margin-left: auto; margin-right: auto; text-align: center; }
.text-center { text-align: center; }
.mt-l { margin-top: 32px; }

.kbd {
  font-family: var(--font-mono);
  font-size: .82rem;
  padding: 2px 6px;
  background: var(--bg-mute);
  border: 1px solid var(--border);
  border-radius: var(--radius-s);
  color: var(--primary);
}