/* ==========================================================================
   Shadows of Kurgansk — design system «Зона»
   Contaminated post-soviet backwoods: fog, rust, anomaly glow.
   ========================================================================== */

/* ---------- Tokens ---------- */
:root {
  /* Colors */
  --bg: #0b0d0c;
  --surface: #121614;
  --surface-2: #1a1f1c;
  --line: #2a312d;
  --line-strong: #3a433e;
  --text: #d9d6cc;
  --text-strong: #f1eee4;
  --muted: #8b918a;
  --accent: #c4572e;          /* rust / warning */
  --accent-hover: #df6a3d;
  --anomaly: #b5c94a;         /* toxic glow, used sparingly */
  --anomaly-soft: rgba(181, 201, 74, 0.14);

  /* Typography */
  --font-display: "Oswald", "Arial Narrow", Impact, sans-serif;
  --font-body: "PT Sans", "Segoe UI", Roboto, Arial, sans-serif;
  --font-mono: "PT Mono", ui-monospace, Menlo, Consolas, monospace;

  --fs-xs: 0.75rem;
  --fs-sm: 0.875rem;
  --fs-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --fs-lg: clamp(1.125rem, 1rem + 0.5vw, 1.375rem);
  --fs-h2: clamp(1.75rem, 1.2rem + 2.4vw, 3.25rem);

  /* Spacing (4px grid) */
  --s-1: 4px;  --s-2: 8px;  --s-3: 12px; --s-4: 16px;
  --s-5: 24px; --s-6: 32px; --s-7: 48px; --s-8: 64px; --s-9: 96px;

  --section-y: clamp(64px, 6vw + 32px, 128px);
  --container: 1200px;
  --gutter: 16px;
  --nav-h: 64px;

  --radius: 2px;
  --ease: cubic-bezier(0.2, 0.7, 0.2, 1);
  --hazard: repeating-linear-gradient(
    -45deg,
    var(--accent) 0 6px,
    transparent 6px 12px
  );
}

@media (min-width: 600px) {
  :root { --gutter: 24px; }
}
@media (min-width: 1024px) {
  :root { --gutter: 40px; --nav-h: 72px; }
}

/* ---------- Base ---------- */
*, *::before, *::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  background: var(--bg);
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: var(--fs-base);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* Film grain over everything */
body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 100;
  pointer-events: none;
  opacity: 0.07;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='3' stitchTiles='stitch'/%3E%3CfeColorMatrix values='0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0.9 0'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

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

a { color: inherit; }

::selection { background: var(--accent); color: var(--text-strong); }

:focus-visible {
  outline: 2px solid var(--anomaly);
  outline-offset: 3px;
}

.container {
  width: 100%;
  max-width: calc(var(--container) + var(--gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

.skip-link {
  position: absolute;
  left: var(--gutter);
  top: -100px;
  z-index: 200;
  padding: var(--s-2) var(--s-4);
  background: var(--anomaly);
  color: var(--bg);
  font-weight: 700;
}
.skip-link:focus { top: var(--s-2); }

.text-link {
  color: var(--anomaly);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  transition: color 0.2s;
}
.text-link:hover { color: var(--text-strong); }

/* ---------- Navigation ---------- */
.nav {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 50;
  height: var(--nav-h);
  transition: background-color 0.3s, border-color 0.3s, backdrop-filter 0.3s;
  border-bottom: 1px solid transparent;
}
.nav.is-scrolled {
  background: rgba(11, 13, 12, 0.82);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border-bottom-color: var(--line);
}
.nav__inner {
  height: 100%;
  display: flex;
  align-items: center;
  gap: var(--s-5);
}
.nav__brand {
  flex: none;
  display: block;
  width: 112px;
  opacity: 0;
  transform: translateY(-4px);
  transition: opacity 0.3s, transform 0.3s;
  pointer-events: none;
}
.nav.is-scrolled .nav__brand {
  opacity: 1;
  transform: none;
  pointer-events: auto;
}
.nav__menu {
  display: flex;
  gap: var(--s-1);
  margin: 0 0 0 auto;
  padding: 0;
  list-style: none;
}
.nav__link {
  position: relative;
  display: block;
  padding: var(--s-2) var(--s-3);
  font-family: var(--font-display);
  font-size: var(--fs-sm);
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--muted);
  transition: color 0.2s;
}
.nav__link::after {
  content: "";
  position: absolute;
  left: var(--s-3);
  right: var(--s-3);
  bottom: 2px;
  height: 2px;
  background: var(--anomaly);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s var(--ease);
}
.nav__link:hover { color: var(--text-strong); }
.nav__link.is-active { color: var(--text-strong); }
.nav__link.is-active::after { transform: scaleX(1); }

.nav__toggle {
  display: none;
  margin-left: auto;
  width: 44px;
  height: 44px;
  padding: 0;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  background: rgba(11, 13, 12, 0.6);
  color: var(--text-strong);
  cursor: pointer;
}
.nav__toggle-bar,
.nav__toggle-bar::before,
.nav__toggle-bar::after {
  display: block;
  width: 20px;
  height: 2px;
  margin: 0 auto;
  background: currentColor;
  transition: transform 0.3s var(--ease), background-color 0.2s;
}
.nav__toggle-bar { position: relative; }
.nav__toggle-bar::before,
.nav__toggle-bar::after { content: ""; position: absolute; left: 0; }
.nav__toggle-bar::before { top: -6px; }
.nav__toggle-bar::after { top: 6px; }
.nav__toggle[aria-expanded="true"] .nav__toggle-bar { background: transparent; }
.nav__toggle[aria-expanded="true"] .nav__toggle-bar::before { transform: translateY(6px) rotate(45deg); }
.nav__toggle[aria-expanded="true"] .nav__toggle-bar::after { transform: translateY(-6px) rotate(-45deg); }

/* Language picker */
.lang {
  position: relative;
  flex: none;
}
.lang__current {
  display: flex;
  align-items: center;
  gap: var(--s-2);
  height: 40px;
  padding: 0 var(--s-3);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  background: rgba(11, 13, 12, 0.6);
  color: var(--text-strong);
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  cursor: pointer;
  transition: border-color 0.2s;
}
.lang__current:hover { border-color: var(--muted); }
.lang__code {
  padding: 1px 5px;
  background: var(--anomaly);
  color: var(--bg);
  font-weight: 700;
  font-size: var(--fs-xs);
}
.lang__chevron {
  width: 10px;
  height: 10px;
  transition: transform 0.2s;
}
.lang__current[aria-expanded="true"] .lang__chevron { transform: rotate(180deg); }
.lang__list {
  position: absolute;
  right: 0;
  top: calc(100% + 6px);
  min-width: 100%;
  margin: 0;
  padding: var(--s-1);
  list-style: none;
  background: var(--surface);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.5);
}
.lang__list[hidden],
.lang__option[hidden] { display: none; }
.lang__option {
  width: 100%;
  border: 0;
  background: none;
  cursor: pointer;
  text-align: left;
  display: flex;
  align-items: center;
  gap: var(--s-2);
  padding: var(--s-2) var(--s-3);
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  text-decoration: none;
  color: var(--text);
  white-space: nowrap;
}
.lang__option:hover { background: var(--surface-2); color: var(--text-strong); }
.lang__option .lang__code { background: var(--line-strong); color: var(--text-strong); }

@media (max-width: 899px) {
  .nav__toggle { display: block; }
  .nav__brand { width: 96px; }
  .nav__menu {
    position: fixed;
    inset: var(--nav-h) 0 0 0;
    flex-direction: column;
    gap: 0;
    margin: 0;
    padding: var(--s-5) var(--gutter);
    background: rgba(11, 13, 12, 0.97);
    border-top: 1px solid var(--line);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: opacity 0.25s, transform 0.25s var(--ease), visibility 0s 0.25s;
  }
  .nav.is-open .nav__menu {
    opacity: 1;
    visibility: visible;
    transform: none;
    transition: opacity 0.25s, transform 0.25s var(--ease);
  }
  .nav.is-open {
    background: rgba(11, 13, 12, 0.97);
    border-bottom-color: var(--line);
    /* backdrop-filter would become the containing block of the fixed menu */
    -webkit-backdrop-filter: none;
    backdrop-filter: none;
  }
  .nav.is-open .nav__brand { opacity: 1; transform: none; pointer-events: auto; }
  .nav__link {
    padding: var(--s-4) 0;
    font-size: 1.5rem;
    border-bottom: 1px solid var(--line);
  }
  .nav__link::after { left: 0; right: auto; width: 32px; bottom: -1px; }
  .lang__label { display: none; }
}

/* ---------- Hero ---------- */
/* The trailer is a looping title card with the logo baked in,
   so it is always shown uncropped horizontally at 16:9. */
.hero {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  max-height: 100vh;
  max-height: 100svh;
  overflow: hidden;
  isolation: isolate;
  background: #000;
}
.hero__video {
  position: absolute;
  inset: 0;
  z-index: -2;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 30%;
}
.hero::before {
  /* vignette + fade into the page */
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(ellipse at 50% 40%, rgba(11, 13, 12, 0) 55%, rgba(11, 13, 12, 0.6) 100%),
    linear-gradient(180deg, rgba(11, 13, 12, 0.6) 0%, rgba(11, 13, 12, 0) 14%, rgba(11, 13, 12, 0) 75%, var(--bg) 100%);
}
.hero::after {
  /* scanlines */
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  opacity: 0.2;
  background: repeating-linear-gradient(0deg, rgba(0, 0, 0, 0.35) 0 1px, transparent 1px 3px);
}
.hero__next {
  position: absolute;
  left: 50%;
  bottom: var(--s-5);
  translate: -50% 0;
  display: grid;
  place-items: center;
  width: 48px;
  height: 48px;
  border: 1px solid rgba(217, 214, 204, 0.35);
  border-radius: 50%;
  background: rgba(11, 13, 12, 0.4);
  color: var(--text-strong);
  transition: border-color 0.2s, color 0.2s;
}
.hero__next svg { width: 18px; height: 18px; animation: drift 2.4s var(--ease) infinite; }
.hero__next:hover { border-color: var(--anomaly); color: var(--anomaly); }

@media (max-width: 899px) {
  /* keep the baked-in logo clear of the fixed nav */
  .hero { margin-top: var(--nav-h); }
  .hero::before {
    background: linear-gradient(180deg, rgba(11, 13, 12, 0) 70%, var(--bg) 100%);
  }
  .hero__next { display: none; }
}

@keyframes drift {
  0%, 100% { transform: translateY(-3px); opacity: 0.6; }
  50% { transform: translateY(4px); opacity: 1; }
}

/* ---------- Sections ---------- */
.section {
  position: relative;
  padding-block: var(--section-y);
  scroll-margin-top: calc(var(--nav-h) - 1px);
}
.section--alt {
  background:
    linear-gradient(180deg, var(--bg) 0%, var(--surface) 12%, var(--surface) 88%, var(--bg) 100%);
}

.section__head {
  margin-bottom: clamp(32px, 4vw, 56px);
}
.section__index {
  display: flex;
  align-items: center;
  gap: var(--s-3);
  margin: 0 0 var(--s-3);
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted);
}
.section__index::before {
  content: "";
  width: 36px;
  height: 8px;
  background: var(--hazard);
}
.section__index b { color: var(--anomaly); font-weight: 400; }
.section__title {
  margin: 0;
  max-width: 22ch;
  font-family: var(--font-display);
  font-size: var(--fs-h2);
  font-weight: 600;
  line-height: 1.05;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--text-strong);
}

.prose {
  margin: 0;
  font-size: var(--fs-lg);
  line-height: 1.7;
  color: var(--text);
  max-width: 60ch;
}

/* Split: text + image */
.split {
  display: grid;
  gap: var(--s-7);
  align-items: center;
}
@media (min-width: 900px) {
  .split { grid-template-columns: 1fr 1fr; gap: var(--s-8); }
  .split--reverse .split__media { order: -1; }
}

/* Image frame with corner reticle marks */
.frame {
  position: relative;
  margin: 0;
  padding: var(--s-3);
}
.frame img {
  width: 100%;
  aspect-ratio: 515 / 333;
  object-fit: cover;
  filter: saturate(0.85);
}
.frame::before,
.frame::after {
  content: "";
  position: absolute;
  width: 28px;
  height: 28px;
  border: 2px solid var(--accent);
  pointer-events: none;
}
.frame::before { top: 0; left: 0; border-right: 0; border-bottom: 0; }
.frame::after { right: 0; bottom: 0; border-left: 0; border-top: 0; }

/* ---------- Features ---------- */
.features {
  display: grid;
  gap: var(--s-4);
  margin: 0;
  padding: 0;
  list-style: none;
  grid-template-columns: 1fr;
}
@media (min-width: 600px) {
  .features { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 1100px) {
  .features { grid-template-columns: repeat(4, 1fr); }
}
.feature {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: var(--s-4);
  padding: var(--s-5);
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-top: 2px solid var(--line-strong);
  transition: border-color 0.25s, transform 0.25s var(--ease);
}
.feature:hover {
  border-top-color: var(--anomaly);
  transform: translateY(-3px);
}
.feature__icon {
  display: grid;
  place-items: center;
  width: 56px;
  height: 56px;
  border: 1px solid var(--line-strong);
  background: var(--anomaly-soft);
  color: var(--anomaly);
}
.feature__icon svg { width: 28px; height: 28px; }
.feature__text {
  margin: 0;
  font-size: var(--fs-base);
  line-height: 1.55;
}

/* ---------- Gallery ---------- */
.gallery {
  display: grid;
  gap: var(--s-4);
}
.gallery__stage {
  position: relative;
  margin: 0;
  background: #000;
  border: 1px solid var(--line);
  overflow: hidden;
}
.gallery__image {
  width: 100%;
  aspect-ratio: 1092 / 614;
  object-fit: cover;
  transition: opacity 0.25s;
}
.gallery__image.is-loading { opacity: 0.4; }
.gallery__counter {
  position: absolute;
  left: var(--s-3);
  top: var(--s-3);
  padding: 2px var(--s-2);
  background: rgba(11, 13, 12, 0.75);
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.12em;
  color: var(--text-strong);
}
.gallery__counter b { color: var(--anomaly); font-weight: 400; }
.gallery__thumbs {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: var(--s-3);
  margin: 0;
  padding: 0;
  list-style: none;
}
.gallery__thumb {
  position: relative;
  display: block;
  border: 1px solid var(--line);
  opacity: 0.55;
  transition: opacity 0.2s, border-color 0.2s;
}
.gallery__thumb img {
  width: 100%;
  aspect-ratio: 186 / 105;
  object-fit: cover;
}
.gallery__thumb:hover { opacity: 0.9; }
.gallery__thumb[aria-current="true"] {
  opacity: 1;
  border-color: var(--anomaly);
  box-shadow: 0 0 0 1px var(--anomaly);
}
@media (max-width: 599px) {
  .gallery__thumbs {
    grid-template-columns: none;
    grid-auto-flow: column;
    grid-auto-columns: 42%;
    overflow-x: auto;
    scroll-snap-type: x mandatory;
    padding-bottom: var(--s-2);
  }
  .gallery__thumbs li { scroll-snap-align: start; }
}

/* ---------- System requirements ---------- */
.specs {
  display: grid;
  gap: var(--s-5);
}
@media (min-width: 800px) {
  .specs { grid-template-columns: 1fr 1fr; }
}
.spec {
  padding: var(--s-5);
  background: var(--surface-2);
  border: 1px solid var(--line);
}
@media (min-width: 600px) {
  .spec { padding: var(--s-6); }
}
.spec__title {
  margin: 0 0 var(--s-4);
  padding-bottom: var(--s-3);
  border-bottom: 1px solid var(--line-strong);
  font-family: var(--font-display);
  font-size: var(--fs-lg);
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-strong);
}
.spec--rec .spec__title { border-bottom-color: var(--accent); }
.spec__list {
  display: grid;
  grid-template-columns: minmax(0, auto) minmax(0, 1fr);
  gap: var(--s-3) var(--s-5);
  margin: 0;
}
.spec__list dt {
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  color: var(--muted);
  padding-top: 2px;
}
.spec__list dd {
  margin: 0;
  color: var(--text-strong);
}
@media (max-width: 420px) {
  .spec__list { grid-template-columns: 1fr; gap: 0; }
  .spec__list dd { margin-bottom: var(--s-3); }
}

/* ---------- Footer ---------- */
.footer {
  padding-block: var(--s-8) var(--s-6);
  background: #070908;
  border-top: 1px solid var(--line);
}
.footer::before {
  content: "";
  display: block;
  height: 6px;
  margin-top: calc(-1 * var(--s-8) - 1px);
  margin-bottom: var(--s-8);
  background: var(--hazard);
  opacity: 0.6;
}
.footer__platforms {
  display: flex;
  justify-content: center;
  padding-bottom: var(--s-6);
  margin-bottom: var(--s-6);
  border-bottom: 1px solid var(--line);
}
.footer__platforms img {
  width: 908px;
  opacity: 0.75;
}
.footer__bottom {
  display: grid;
  gap: var(--s-6);
  align-items: center;
}
@media (min-width: 900px) {
  .footer__bottom { grid-template-columns: auto 1fr; gap: var(--s-8); }
}
.footer__logos {
  display: flex;
  align-items: center;
  gap: var(--s-5);
}
.footer__logos img { opacity: 0.8; transition: opacity 0.2s; }
.footer__logos a:hover img { opacity: 1; }
.footer__logo-gaijin { width: 146px; }
.footer__logo-yadon { width: 150px; }
.footer__links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s-2) var(--s-5);
  margin: 0 0 var(--s-3);
  padding: 0;
  list-style: none;
}
.footer__link {
  font-size: var(--fs-sm);
  text-decoration: none;
  color: var(--text);
  border-bottom: 1px solid var(--line-strong);
  transition: color 0.2s, border-color 0.2s;
}
.footer__link:hover { color: var(--anomaly); border-bottom-color: var(--anomaly); }
.footer__copy {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  line-height: 1.7;
  color: var(--muted);
}
.footer__copy p { margin: 0; }

/* ---------- Motion preferences ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation: none !important;
    transition: none !important;
  }
}