/* Layout: full-screen slides that snap on scroll, copy anchored bottom-left.
   Behind them one fixed scene: digital rain, and a 3D dot globe wrapped in the
   server network, which flies to a new pose as each slide comes in.
   One dark world, in the portal's palette. */
:root {
  color-scheme: dark;
  --bg-rgb: 6 9 11;          --bg: rgb(var(--bg-rgb));
  --panel-rgb: 17 21 27;     --panel: rgb(var(--panel-rgb));
  --panel-2-rgb: 21 27 35;   --panel-2: rgb(var(--panel-2-rgb));
  --line-rgb: 39 49 61;      --line: rgb(var(--line-rgb));
  --text-rgb: 231 237 243;   --text: rgb(var(--text-rgb));
  --soft-rgb: 186 197 211;   --soft: rgb(var(--soft-rgb));
  --muted-rgb: 141 153 168;  --muted: rgb(var(--muted-rgb));
  --accent-rgb: 98 210 162;  --accent: rgb(var(--accent-rgb));
  --accent-2-rgb: 90 167 255; --accent-2: rgb(var(--accent-2-rgb));
  --matrix-rgb: 49 255 122;
  --on-accent-rgb: 7 17 13;  --on-accent: rgb(var(--on-accent-rgb));
  --trace-start-rgb: 182 156 255;
  --trace-end-rgb: 76 195 245;

  --font-display: "Unbounded", "Noto Sans SC", ui-sans-serif, system-ui, sans-serif;
  --font-body: "Inter", "Noto Sans SC", ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --radius: 8px;
  --gutter-l: max(24px, env(safe-area-inset-left, 0px));
  --gutter-r: max(24px, env(safe-area-inset-right, 0px));
}

* { box-sizing: border-box; }
html { scroll-snap-type: y proximity; scroll-behavior: smooth; background: var(--bg); }
body {
  margin: 0; background: var(--bg); color: var(--text);
  font: 400 16px/1.6 var(--font-body);
  -webkit-font-smoothing: antialiased; overflow-x: hidden;
}
body::before {
  content: ""; position: fixed; inset: 0 0 auto; height: env(safe-area-inset-top, 0px);
  z-index: 30; background: var(--bg);
}
h1, h2, h3, p { margin: 0; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; border: 0; background: none; cursor: pointer; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 4px; }
html[lang="zh-Hans"] { --font-display: "Noto Sans SC", "Unbounded", sans-serif; }
html[lang="zh-Hans"] body { line-break: strict; }
html[lang="km"] { --font-display: "Kantumruy Pro", "Noto Sans Khmer", ui-sans-serif, sans-serif; --font-body: "Kantumruy Pro", "Noto Sans Khmer", ui-sans-serif, sans-serif; }
html[lang="km"] body { line-height: 1.8; }

/* Scene */
.scene { position: fixed; inset: 0; z-index: 0; pointer-events: none; }
.scene canvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; }
#rain { opacity: 0.5; }
.veil {
  position: fixed; inset: 0; z-index: 1; pointer-events: none;
  background:
    linear-gradient(90deg, rgb(var(--bg-rgb) / 0.92) 0%, rgb(var(--bg-rgb) / 0.55) 34%, transparent 58%),
    linear-gradient(0deg, rgb(var(--bg-rgb) / 0.9) 0%, transparent 38%),
    linear-gradient(180deg, rgb(var(--bg-rgb) / 0.75) 0%, transparent 16%);
}

/* Header */
.top {
  position: fixed; top: env(safe-area-inset-top, 0px); left: 0; right: 0; z-index: 20;
  transition: background .3s, border-color .3s;
  border-bottom: 1px solid transparent;
}
.top.scrolled {
  background: rgb(var(--bg-rgb) / 0.72); border-color: rgb(var(--line-rgb) / 0.5);
  backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
}
.top-in { display: flex; align-items: center; gap: 28px; padding: 18px var(--gutter-r) 18px var(--gutter-l); }
.brand { display: flex; align-items: center; gap: 12px; flex: none; }
.logo { display: block; width: auto; height: 40px; filter: drop-shadow(0 0 10px rgb(var(--accent-rgb) / 0.45)); }
.final-logo { width: auto; height: 120px; flex: none; filter: drop-shadow(0 0 24px rgb(var(--accent-rgb) / 0.4)); }
.final-main { display: flex; align-items: center; gap: 28px; min-width: 0; }
.final-main > div { min-width: 0; }
.brand-name { font: 600 16px/1 var(--font-display); letter-spacing: 0.14em; text-transform: uppercase; }
.brand-name span { color: var(--accent); }
.nav { display: flex; gap: 26px; }
.nav a {
  position: relative; padding: 6px 0; font: 500 12px/1 var(--font-display); letter-spacing: 0.14em;
  text-transform: uppercase; color: var(--soft); transition: color .2s;
}
html[lang="zh-Hans"] .nav a { font-family: var(--font-body); font-size: 14px; letter-spacing: 0.1em; }
.nav a::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: -2px; height: 1px; background: var(--accent);
  transform: scaleX(0); transform-origin: left; transition: transform .25s;
}
.nav a:hover, .nav a.active { color: var(--text); }
.nav a:hover::after, .nav a.active::after { transform: scaleX(1); }
.top-actions { margin-left: auto; display: flex; align-items: center; gap: 14px; }
.lang { display: inline-flex; gap: 2px; padding: 3px; border-radius: 999px; border: 1px solid rgb(var(--line-rgb) / 0.9); background: rgb(var(--bg-rgb) / 0.5); }
.lang button {
  min-width: 40px; height: 28px; padding: 0 10px; border-radius: 999px;
  font: 600 11.5px/1 var(--font-mono); letter-spacing: 0.06em; color: var(--muted); transition: background .15s, color .15s;
}
.lang button[aria-pressed="true"] { background: var(--accent); color: var(--on-accent); }
.lang button:not([aria-pressed="true"]):hover { color: var(--text); }
.lang button[data-lang="zh"] { font-family: "Noto Sans SC", var(--font-mono); letter-spacing: 0; }
.lang button[data-lang="km"] { font-family: "Kantumruy Pro", var(--font-mono); font-size: 12.5px; letter-spacing: 0; }

/* Buttons, SpaceX-like: thin frame, uppercase, fills on hover */
.btn {
  position: relative; display: inline-flex; align-items: center; justify-content: center; gap: 10px;
  min-height: 50px; padding: 0 30px; border: 2px solid var(--text); color: var(--text); overflow: hidden; isolation: isolate;
  font: 600 13px/1 var(--font-display); letter-spacing: 0.14em; text-transform: uppercase; white-space: nowrap;
  transition: color .3s;
}
html[lang="zh-Hans"] .btn { font-family: var(--font-body); font-size: 15px; letter-spacing: 0.12em; }
.btn::before {
  content: ""; position: absolute; inset: 0; z-index: -1; background: var(--text);
  transform: translateY(101%); transition: transform .3s cubic-bezier(.2,.7,.2,1);
}
.btn:hover { color: var(--bg); }
.btn:hover::before { transform: translateY(0); }
.btn-accent { border-color: var(--accent); background: var(--accent); color: var(--on-accent); }
.btn-accent::before { background: var(--text); }
.btn-sm { min-height: 38px; padding: 0 18px; font-size: 11.5px; border-width: 1.5px; }
.btn svg { width: 16px; height: 16px; }

/* Slides */
main { position: relative; z-index: 3; }
.slide {
  position: relative; display: flex; align-items: flex-end;
  min-height: 100vh; min-height: 100svh; scroll-snap-align: start;
}
.slide-in {
  width: 100%; max-width: 1440px; margin: 0 auto;
  padding-top: 110px; padding-bottom: 13vh; padding-left: var(--gutter-l); padding-right: var(--gutter-r);
}
.copy { display: grid; gap: 22px; max-width: 760px; min-width: 0; }
.copy > p, .copy > ul, .copy > ol, .copy > dl { max-width: 600px; }
.index {
  display: flex; align-items: center; gap: 14px;
  font: 500 12px/1 var(--font-mono); letter-spacing: 0.16em; text-transform: uppercase; color: var(--accent);
}
.index::before { content: ""; width: 34px; height: 1px; background: var(--accent); }
.index b { color: var(--muted); font-weight: 500; }
html[lang="zh-Hans"] .index span { font-family: var(--font-body); letter-spacing: 0.2em; }
h1, h2 {
  font-family: var(--font-display); font-weight: 600; text-transform: uppercase;
  letter-spacing: 0.01em; text-wrap: balance; overflow-wrap: normal; word-break: normal; hyphens: manual;
}
h1 { font-size: clamp(32px, 6.2vw, 84px); line-height: 1.0; }
h2 { font-size: clamp(28px, 4.4vw, 58px); line-height: 1.05; }
html[lang="ru"] h1 { font-size: clamp(30px, 5.6vw, 76px); }
html[lang="ru"] h2 { font-size: clamp(24px, 3.9vw, 52px); }
html[lang="zh-Hans"] h1, html[lang="zh-Hans"] h2 { font-weight: 900; letter-spacing: 0.04em; line-height: 1.18; }
h1 em, h2 em { font-style: normal; color: var(--accent); text-shadow: 0 0 28px rgb(var(--accent-rgb) / 0.45); }
.copy p { color: var(--soft); font-size: 17.5px; max-width: 34em; }
.actions { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 6px; }
.meta { display: flex; flex-wrap: wrap; gap: 8px 22px; padding: 0; margin: 0; list-style: none; }
.meta li { display: flex; align-items: center; gap: 8px; color: var(--muted); font: 500 12.5px/1.3 var(--font-mono); letter-spacing: 0.04em; text-transform: uppercase; }
html[lang="zh-Hans"] .meta li { font-family: var(--font-body); font-size: 14px; }
.meta li::before { content: ""; width: 6px; height: 6px; background: var(--accent); box-shadow: 0 0 8px var(--accent); }
.tag {
  justify-self: start; padding: 7px 12px; border: 1px solid rgb(var(--accent-rgb) / 0.45);
  font: 500 12px/1.2 var(--font-mono); letter-spacing: 0.06em; color: var(--accent); background: rgb(var(--accent-rgb) / 0.07);
}

/* Hero extras */
.hud {
  position: absolute; right: calc(var(--gutter-r) + 48px); bottom: 13vh; z-index: 2;
  display: grid; gap: 7px; padding: 14px 18px; min-width: 260px;
  font: 500 12px/1.3 var(--font-mono); letter-spacing: 0.06em;
  border: 1px solid rgb(var(--accent-rgb) / 0.4); background: rgb(var(--bg-rgb) / 0.62);
  backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px);
}
.hud::before, .hud::after { content: ""; position: absolute; width: 10px; height: 10px; border: 2px solid var(--accent); }
.hud::before { top: -2px; left: -2px; border-right: 0; border-bottom: 0; }
.hud::after { bottom: -2px; right: -2px; border-left: 0; border-top: 0; }
.hud div { display: grid; grid-template-columns: 92px 1fr; gap: 10px; }
.hud dt { color: var(--muted); text-transform: uppercase; }
html[lang="zh-Hans"] .hud dt { font-family: var(--font-body); }
.hud dd { margin: 0; color: var(--text); font-variant-numeric: tabular-nums; transition: opacity .25s; }
.hud .ok { color: var(--accent); }
.hud .from { color: rgb(var(--trace-start-rgb)); }
.hud .to { color: rgb(var(--trace-end-rgb)); }
.scroll-cue {
  position: absolute; left: 50%; bottom: 26px; transform: translateX(-50%);
  display: grid; justify-items: center; gap: 8px; color: var(--muted);
  font: 500 10.5px/1 var(--font-mono); letter-spacing: 0.24em; text-transform: uppercase;
}
.scroll-cue i { width: 1px; height: 34px; background: linear-gradient(var(--accent), transparent); animation: cue 1.8s ease-in-out infinite; transform-origin: top; }
@keyframes cue { 0% { transform: scaleY(0); } 50% { transform: scaleY(1); } 100% { transform: scaleY(1); opacity: 0; } }

/* Network slide */
.figures { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 0; margin: 4px 0 0; border-top: 1px solid rgb(var(--line-rgb) / 0.8); }
.figures > div { display: grid; gap: 4px; padding: 16px 16px 0 0; }
.figures dd { order: 1; margin: 0; font: 600 34px/1 var(--font-display); color: var(--text); font-variant-numeric: tabular-nums; }
.figures dd small { font-size: 0.5em; color: var(--accent); }
.figures dt { order: 2; color: var(--muted); font-size: 13px; line-height: 1.35; }
.regions { display: grid; gap: 8px; padding: 0; margin: 0; list-style: none; }
.regions li {
  display: flex; flex-wrap: wrap; align-items: baseline; gap: 6px 14px; padding: 9px 0;
  border-bottom: 1px solid rgb(var(--line-rgb) / 0.6);
}
.regions strong { min-width: 190px; font: 500 12px/1.3 var(--font-display); letter-spacing: 0.12em; text-transform: uppercase; color: var(--text); }
html[lang="zh-Hans"] .regions strong { font-family: var(--font-body); font-size: 14px; }
.regions span { font: 500 12.5px/1.3 var(--font-mono); letter-spacing: 0.1em; color: var(--accent); }

/* Steps */
.steps { display: grid; gap: 0; padding: 0; margin: 0; list-style: none; counter-reset: step; }
.steps li {
  display: grid; grid-template-columns: 52px minmax(0, 1fr); gap: 2px 16px; padding: 16px 0;
  border-top: 1px solid rgb(var(--line-rgb) / 0.8);
}
.steps li::before {
  counter-increment: step; content: "0" counter(step); grid-row: span 2;
  font: 600 22px/1.1 var(--font-display); color: var(--accent);
}
.steps h3 { font-size: 17px; font-weight: 600; }
.steps p { color: var(--soft); font-size: 15px; }
.platforms { display: flex; flex-wrap: wrap; gap: 8px; padding: 0; margin: 0; list-style: none; }
.platforms li { padding: 6px 12px; border: 1px solid rgb(var(--line-rgb)); font: 500 12px/1.2 var(--font-mono); letter-spacing: 0.06em; color: var(--soft); background: rgb(var(--bg-rgb) / 0.5); }

/* FAQ + final */
.slide.last { align-items: stretch; }
.slide.last .slide-in { display: grid; align-content: space-between; gap: 56px; padding-bottom: 0; }
.faq-grid { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); gap: 48px; align-items: start; }
.faq { display: grid; }
.faq details { border-top: 1px solid rgb(var(--line-rgb) / 0.8); }
.faq details:last-child { border-bottom: 1px solid rgb(var(--line-rgb) / 0.8); }
.faq summary {
  display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 20px 0;
  cursor: pointer; list-style: none; font-weight: 600; font-size: 17px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; flex: none; font: 400 22px/1 var(--font-mono); color: var(--accent); transition: transform .25s; }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details p { padding: 0 0 20px; color: var(--soft); max-width: 46em; }
.final {
  position: relative; display: flex; flex-wrap: wrap; align-items: flex-end; justify-content: space-between; gap: 24px;
  padding: 40px 0 36px; border-top: 1px solid rgb(var(--accent-rgb) / 0.5);
}
.final h2 { font-size: clamp(24px, 3.4vw, 44px); max-width: 16em; }
.final p { color: var(--soft); margin-top: 10px; }
footer {
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: 14px; padding: 22px 0 28px;
  border-top: 1px solid rgb(var(--line-rgb) / 0.6); color: var(--muted);
  font: 500 11.5px/1.3 var(--font-mono); letter-spacing: 0.1em; text-transform: uppercase;
}
html[lang="zh-Hans"] footer { font-family: var(--font-body); font-size: 13px; }
footer nav { display: flex; flex-wrap: wrap; gap: 22px; }
footer a:hover { color: var(--text); }

/* Slide rail */
.rail {
  position: fixed; right: max(18px, env(safe-area-inset-right, 0px)); top: 50%; transform: translateY(-50%); z-index: 15;
  display: grid; gap: 4px; padding: 0; margin: 0; list-style: none;
}
.rail a { display: flex; align-items: center; justify-content: flex-end; gap: 12px; padding: 7px 0; }
.rail span {
  font: 500 11px/1 var(--font-mono); letter-spacing: 0.14em; text-transform: uppercase; color: var(--muted);
  opacity: 0; transform: translateX(6px); transition: opacity .2s, transform .2s;
}
html[lang="zh-Hans"] .rail span { font-family: var(--font-body); font-size: 12px; }
.rail i { width: 14px; height: 2px; background: rgb(var(--text-rgb) / 0.3); transition: width .3s, background .3s; }
.rail a:hover span, .rail a.active span { opacity: 1; transform: none; }
.rail a.active span { color: var(--text); }
.rail a.active i { width: 30px; background: var(--accent); box-shadow: 0 0 10px var(--accent); }

html[lang="km"] :is(h1, h2, .nav a, .btn, .index span, .meta li, .regions strong, .rail span, footer, .hud dt, .tag, .figures dt) {
  letter-spacing: 0; text-transform: none;
}
html[lang="km"] :is(.nav a, .btn, .index span, .meta li, .regions strong, .rail span, footer, .hud dt) { font-family: var(--font-body); }
html[lang="km"] h1, html[lang="km"] h2 { font-weight: 700; line-height: 1.4; }
html[lang="km"] h1 { font-size: clamp(30px, 5.4vw, 72px); }
html[lang="km"] h2 { font-size: clamp(24px, 3.8vw, 50px); }
html[lang="km"] .nav a, html[lang="km"] .btn { font-size: 14px; }

@media (max-width: 1180px) {
  .nav { display: none; }
  .hud { display: none; }
}
@media (max-width: 900px) {
  .faq-grid { grid-template-columns: minmax(0, 1fr); gap: 20px; }
}
@media (max-width: 760px), (max-aspect-ratio: 9/10) {
  :root { --gutter-l: max(18px, env(safe-area-inset-left, 0px)); --gutter-r: max(18px, env(safe-area-inset-right, 0px)); }
  .veil {
    background:
      linear-gradient(0deg, rgb(var(--bg-rgb) / 0.97) 0%, rgb(var(--bg-rgb) / 0.82) 42%, transparent 64%),
      linear-gradient(180deg, rgb(var(--bg-rgb) / 0.8) 0%, transparent 14%);
  }
  .slide-in { padding-bottom: 72px; }
  .rail { display: none; }
  .copy p { font-size: 16px; }
  .scroll-cue { display: none; }
}
@media (max-width: 560px) {
  .top-in { gap: 12px; padding-block: 14px; }
  .top .btn { display: none; }
  .brand-name { font-size: 14px; letter-spacing: 0.1em; }
  .brand-name span { display: none; }
  .logo { height: 34px; }
  .final-logo { height: 84px; }
  .final-main { gap: 18px; }
  .lang button { min-width: 34px; padding: 0 8px; }
  .actions .btn { flex: 1 1 100%; }
  .figures dd { font-size: 26px; }
  .figures dt { font-size: 12px; }
  .regions strong { min-width: 0; width: 100%; }
  .slide-in { padding-top: 96px; }
}
@media (max-width: 380px) {
  .brand-name { display: none; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .scroll-cue i { animation: none; }
  .btn::before, .rail i, .rail span, .nav a::after { transition: none; }
}