/* ---------- Theme tokens ---------- */
/* Dark is the default theme; light is opt-in via the toggle. */
:root {
  --accent: #1FBF8F;
  --bg: #0a0f14;
  --bg-panel: #10161d;
  --text: #dbe4ea;
  --text-muted: #8fa0ae;
  --border: #1e2933;
  --grid-line: rgba(31, 191, 143, 0.06);
  --glow: rgba(31, 191, 143, 0.35);
  color-scheme: dark;
}

:root[data-theme="light"] {
  --bg: #f2f5f7;
  --bg-panel: #ffffff;
  --text: #151B23;
  --text-muted: #5a6873;
  --border: #d5dde2;
  --grid-line: rgba(21, 27, 35, 0.05);
  --glow: rgba(31, 191, 143, 0.25);
  color-scheme: light;
}

/* ---------- Base ---------- */
* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  background-color: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

h1, h2, h3 {
  line-height: 1.2;
  letter-spacing: 0.02em;
}

h2 {
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-size: 1.3rem;
  color: var(--accent);
}

h2::before { content: "// "; opacity: 0.6; }

a { color: var(--accent); }

/* Theme-dependent logo variant */
.logo { height: 44px; display: none; }
.logo-dark { display: block; }
:root[data-theme="light"] .logo-dark { display: none; }
:root[data-theme="light"] .logo-light { display: block; }

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  gap: 1.5rem;
  padding: 0.6rem 1.5rem;
  background: color-mix(in srgb, var(--bg-panel) 88%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.brand { flex-shrink: 0; }

.site-nav {
  display: flex;
  gap: 1.2rem;
  margin-inline: auto;
  flex-wrap: wrap;
}

.site-nav a {
  color: var(--text);
  text-decoration: none;
  text-transform: uppercase;
  font-size: 0.8rem;
  letter-spacing: 0.12em;
  padding: 0.3rem 0;
  border-bottom: 2px solid transparent;
}

.site-nav a:hover {
  color: var(--accent);
  border-bottom-color: var(--accent);
  text-shadow: 0 0 12px var(--glow);
}

.controls { display: flex; align-items: center; gap: 0.8rem; }

.lang-switch {
  display: flex;
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
}

.lang-switch button {
  border: none;
  background: transparent;
  color: var(--text-muted);
  font: inherit;
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  padding: 0.35rem 0.7rem;
  cursor: pointer;
}

.lang-switch button.active {
  background: var(--accent);
  color: #0a0f14;
  font-weight: 700;
}

#theme-toggle {
  border: 1px solid var(--border);
  border-radius: 6px;
  background: transparent;
  color: var(--text);
  font-size: 1rem;
  padding: 0.3rem 0.6rem;
  cursor: pointer;
}

#theme-toggle:hover { border-color: var(--accent); box-shadow: 0 0 10px var(--glow); }

.icon-moon { display: none; }
:root[data-theme="light"] .icon-sun { display: none; }
:root[data-theme="light"] .icon-moon { display: inline; }

/* ---------- Hero ---------- */
.hero {
  max-width: 68rem;
  margin: 0 auto;
  padding: 5rem 1.5rem 3rem;
  display: flex;
  align-items: center;
  gap: 3rem;
}

.hero-text { flex: 1 1 30rem; }

.hero-kicker {
  color: var(--accent);
  font-family: ui-monospace, "Cascadia Mono", "Fira Code", monospace;
  font-size: 0.85rem;
  letter-spacing: 0.06em;
  text-shadow: 0 0 14px var(--glow);
}

.hero h1 { font-size: clamp(1.9rem, 4.5vw, 3rem); margin: 0.4rem 0 1rem; }

.hero-sub { color: var(--text-muted); font-size: 1.1rem; max-width: 34rem; }

.btn-primary {
  display: inline-block;
  margin-top: 1.2rem;
  padding: 0.7rem 1.6rem;
  background: var(--accent);
  color: #0a0f14;
  font-weight: 700;
  text-decoration: none;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-size: 0.85rem;
  border-radius: 6px;
  box-shadow: 0 0 18px var(--glow);
}

.btn-primary:hover { filter: brightness(1.1); box-shadow: 0 0 28px var(--glow); }

.hero-art { flex: 0 0 auto; }

.hero-art img {
  width: clamp(160px, 22vw, 260px);
  /* the mark is drawn dark — recolor it for the dark background */
  filter: invert(0.92) hue-rotate(180deg) drop-shadow(0 0 24px var(--glow));
  animation: hover-bob 5s ease-in-out infinite;
}

:root[data-theme="light"] .hero-art img { filter: drop-shadow(0 0 24px var(--glow)); }

@keyframes hover-bob {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

/* ---------- Sections & cards ---------- */
.section {
  max-width: 68rem;
  margin: 0 auto;
  padding: 3rem 1.5rem;
}

.section > p { max-width: 46rem; color: var(--text-muted); font-size: 1.05rem; }

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr));
  gap: 1.2rem;
  margin-top: 1.5rem;
}

.card {
  position: relative;
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.5rem;
  transition: border-color 0.2s, box-shadow 0.2s, transform 0.2s;
}

.card:hover {
  border-color: var(--accent);
  box-shadow: 0 0 22px var(--glow);
  transform: translateY(-3px);
}

.card h3 { margin: 0.4rem 0; }

.card p { color: var(--text-muted); margin-bottom: 0; }

.card-num {
  font-family: ui-monospace, "Cascadia Mono", "Fira Code", monospace;
  color: var(--accent);
  opacity: 0.85;
  font-size: 0.85rem;
  letter-spacing: 0.2em;
}

/* Founders */
.founder { text-align: center; }

.avatar {
  width: 84px;
  height: 84px;
  margin: 0 auto 0.8rem;
  display: grid;
  place-items: center;
  font-weight: 700;
  font-size: 1.5rem;
  color: var(--accent);
  background: transparent;
  border: 3px solid var(--accent);
  /* hexagon, like the turtle shell plates */
  clip-path: polygon(50% 0%, 93% 25%, 93% 75%, 50% 100%, 7% 75%, 7% 25%);
  background: color-mix(in srgb, var(--accent) 10%, transparent);
}

.role { color: var(--text-muted); font-size: 0.9rem; margin: 0; }

.founder-mail {
  display: inline-block;
  margin-top: 0.5rem;
  font-size: 0.82rem;
  word-break: break-all;
  text-decoration: none;
}

.founder-mail:hover { text-decoration: underline; text-shadow: 0 0 10px var(--glow); }

/* Contacts */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(14rem, 1fr));
  gap: 1.2rem;
  margin-top: 1.5rem;
}

.contact-item {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: 8px;
  padding: 1rem 1.2rem;
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.contact-label {
  text-transform: uppercase;
  font-size: 0.72rem;
  letter-spacing: 0.15em;
  color: var(--text-muted);
}

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--border);
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
  padding: 1.5rem;
  margin-top: 2rem;
}

/* ---------- 404 page ---------- */
.page-404 {
  min-height: 100vh;
  display: grid;
  place-items: center;
  text-align: center;
  padding: 2rem;
}

.page-404 h1 {
  font-size: clamp(3rem, 10vw, 5rem);
  margin: 0.5rem 0 0;
  color: var(--accent);
  text-shadow: 0 0 24px var(--glow);
}

.page-404 p { color: var(--text-muted); max-width: 28rem; margin: 0.8rem auto; }

.turtle-404 { width: clamp(180px, 30vw, 280px); }

.turtle-404 .body { fill: var(--text); }

.turtle-404 .tail {
  fill: var(--text);
  stroke: var(--text);
  transform-origin: 60px 102px;
  animation: wag 0.7s ease-in-out infinite;
}

@keyframes wag {
  0%, 100% { transform: rotate(-24deg); }
  50% { transform: rotate(24deg); }
}

/* ---------- Sky & Kyiv skyline background ---------- */
.scene {
  position: fixed;
  inset: 0;
  z-index: -1;
  overflow: hidden;
  pointer-events: none;
  background: linear-gradient(#03060d 0%, #0a1322 55%, #16242f 100%);
}

:root[data-theme="light"] .scene {
  background: linear-gradient(#9fcdec 0%, #c9e5f5 55%, #eaf5fb 100%);
}

/* faint Borg grid over the sky */
.scene::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 44px 44px;
}

.scene .stars { position: absolute; inset: 0; width: 100%; height: 100%; }
.scene .stars circle { fill: #d7e6ff; }
.scene .stars .t1 { animation: twinkle 2.4s ease-in-out infinite; }
.scene .stars .t2 { animation: twinkle 3.2s ease-in-out 0.8s infinite; }
.scene .stars .t3 { animation: twinkle 4.1s ease-in-out 1.6s infinite; }

@keyframes twinkle { 0%, 100% { opacity: 0.2; } 50% { opacity: 1; } }

.moon {
  position: absolute;
  top: 9%;
  right: 14%;
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: #e8ecf2;
  box-shadow: 0 0 46px rgba(215, 230, 255, 0.4);
  overflow: hidden;
}

.moon::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: 50%;
  background: #0a1322;
  transform: translateX(-26%);
}

.sun {
  position: absolute;
  top: 10%;
  right: 16%;
  width: 90px;
  height: 90px;
  border-radius: 50%;
  background: radial-gradient(circle, #ffe89a 0%, #ffd76a 55%, rgba(255, 215, 106, 0) 75%);
  box-shadow: 0 0 70px rgba(255, 215, 106, 0.6);
  display: none;
}

.cloud, .cloud::before {
  background: #ffffff;
  border-radius: 999px;
}

.cloud {
  position: absolute;
  width: 150px;
  height: 32px;
  opacity: 0.85;
  display: none;
}

.cloud::before {
  content: "";
  position: absolute;
  width: 72px;
  height: 46px;
  top: -24px;
  left: 36px;
}

.c1 { top: 18%; left: 12%; }
.c2 { top: 30%; left: 58%; transform: scale(0.7); }

:root[data-theme="light"] .sun,
:root[data-theme="light"] .cloud { display: block; }
:root[data-theme="light"] .stars,
:root[data-theme="light"] .moon { display: none; }

.scene .skyline {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 30vh;
  min-height: 170px;
}

.skyline .city { fill: #070c14; }
.skyline .frame { stroke: #070c14; fill: none; }
.skyline .window { fill: #ffd76a; opacity: 0.7; }

:root[data-theme="light"] .skyline .city { fill: #93a9bc; }
:root[data-theme="light"] .skyline .frame { stroke: #93a9bc; }
:root[data-theme="light"] .skyline .window { fill: #31465a; opacity: 0.15; }

/* ---------- Easter egg: the PCB parade ---------- */
.parade {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  height: 120px;
  z-index: 60;
  pointer-events: none;
}

.runner {
  position: absolute;
  bottom: 8px;
  transform: translateX(-180px);
  animation: run-across var(--dur, 13s) linear var(--delay, 0s) forwards;
  filter: drop-shadow(0 0 8px var(--glow));
}

@keyframes run-across {
  from { transform: translateX(-180px); }
  to   { transform: translateX(calc(100vw + 60px)); }
}

.runner .char {
  height: 64px;
  animation: runner-bob 0.45s ease-in-out infinite alternate;
}

.runner .char svg, .runner .char img { height: 100%; display: block; }

@keyframes runner-bob {
  from { transform: translateY(0); }
  to   { transform: translateY(-6px); }
}

.runner .leg { transform-box: fill-box; transform-origin: center top; }
.runner .l1 { animation: leg-swing 0.3s ease-in-out infinite alternate; }
.runner .l2 { animation: leg-swing 0.3s ease-in-out infinite alternate-reverse; }

@keyframes leg-swing {
  from { transform: rotate(16deg); }
  to   { transform: rotate(-16deg); }
}

/* every runner proudly shows their board to the one behind */
.runner .pcb {
  position: absolute;
  width: 38px;
  top: 4px;
  right: -16px;
  transform-origin: bottom left;
  animation: pcb-show 2.6s ease-in-out infinite;
}

@keyframes pcb-show {
  0%, 55%, 100% { transform: rotate(10deg); }
  65%, 85%      { transform: rotate(-40deg) translateY(-6px); }
}

.runner.turtle-run .char img {
  transform: rotate(90deg);
  filter: invert(0.92) hue-rotate(180deg);
}

:root[data-theme="light"] .runner.turtle-run .char img { filter: none; }

.hero-art img { cursor: pointer; pointer-events: auto; }

/* ---------- Borg cubes ---------- */
.borg-cube {
  position: absolute;
  width: var(--s);
  height: var(--s);
  transform-style: preserve-3d;
  animation: cube-spin 18s linear infinite;
  pointer-events: none;
}

.borg-cube .face {
  position: absolute;
  width: 100%;
  height: 100%;
  border: 1px solid var(--accent);
  background: color-mix(in srgb, var(--accent) 8%, transparent);
  box-shadow: inset 0 0 14px var(--glow);
}

.borg-cube .f1 { transform: translateZ(calc(var(--s) / 2)); }
.borg-cube .f2 { transform: rotateY(180deg) translateZ(calc(var(--s) / 2)); }
.borg-cube .f3 { transform: rotateY(90deg) translateZ(calc(var(--s) / 2)); }
.borg-cube .f4 { transform: rotateY(-90deg) translateZ(calc(var(--s) / 2)); }
.borg-cube .f5 { transform: rotateX(90deg) translateZ(calc(var(--s) / 2)); }
.borg-cube .f6 { transform: rotateX(-90deg) translateZ(calc(var(--s) / 2)); }

.cube-a { --s: 72px; top: -16px; right: -34px; }
.cube-b { --s: 42px; bottom: 6px; left: -40px; animation-duration: 26s; animation-direction: reverse; }
.cube-404 { --s: 52px; top: 8px; right: 12%; }

@keyframes cube-spin {
  from { transform: rotateX(-22deg) rotateY(0deg); }
  to   { transform: rotateX(-22deg) rotateY(360deg); }
}

/* ---------- PCB traces ---------- */
.hero { position: relative; }
.hero-text, .hero-art { position: relative; }
.hero-art { z-index: 1; }

.hero-circuit {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

.hero-circuit .traces path,
.circuit-divider .traces path {
  stroke: var(--accent);
  stroke-width: 2;
  fill: none;
  opacity: 0.3;
}

.hero-circuit .vias circle,
.circuit-divider .vias circle {
  fill: var(--bg);
  stroke: var(--accent);
  stroke-width: 2;
  opacity: 0.55;
}

.hero-circuit .pads rect,
.circuit-divider .pads rect {
  fill: var(--accent);
  opacity: 0.4;
}

.hero-circuit .pulses circle,
.circuit-divider .pulses circle {
  fill: var(--accent);
  filter: drop-shadow(0 0 6px var(--accent));
}

.circuit-divider {
  max-width: 68rem;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.circuit-divider svg { display: block; width: 100%; height: auto; }

.circuit-divider .hex {
  fill: color-mix(in srgb, var(--accent) 12%, transparent);
  stroke: var(--accent);
  stroke-width: 2;
  opacity: 0.8;
}

.page-404 > div { position: relative; }

/* ---------- Responsive ---------- */
@media (max-width: 720px) {
  .site-header { flex-wrap: wrap; }
  .site-nav { order: 3; width: 100%; margin: 0.3rem 0 0; }
  .hero { flex-direction: column-reverse; text-align: center; padding-top: 2.5rem; }
  .hero-sub { margin-inline: auto; }
}

@media (prefers-reduced-motion: reduce) {
  .hero-art img, .turtle-404 .tail { animation: none; }
  .borg-cube { animation: none; transform: rotateX(-22deg) rotateY(32deg); }
  .pulses { display: none; }
  .stars circle { animation: none; }
  .parade { display: none; }
  html { scroll-behavior: auto; }
}