/* Light-Science 官网 · 样式
   色板取自 Logo：深蓝 #102A43、青绿 #008A7B、琥珀亮点；米白纸面画布。 */

:root {
  color-scheme: light;
  --paper: #f6f1e7;
  --paper-raised: #fbf8f2;
  --paper-sunk: #efe8da;
  --line: #e0d6c4;
  --line-strong: #cbbfa9;
  --ink: #102a43;
  --ink-2: #33495e;
  --muted: #586a7b;
  --teal: #008a7b;
  --teal-text: #00756a;
  --teal-soft: #dcefe9;
  --amber: #f2a51e;
  --amber-text: #9a6208;
  --amber-soft: #fbeccb;

  --panel: #0e2239;
  --panel-2: #132b45;
  --panel-line: #223f5c;
  --panel-text: #dbe5ee;
  --panel-muted: #8ea5b8;
  --panel-teal: #36c7b1;

  --serif: "Noto Serif SC", "Source Han Serif SC", "Source Han Serif CN", "Songti SC", "STSong", "Microsoft YaHei", serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
  --mono: "JetBrains Mono", "Cascadia Code", "SF Mono", Menlo, Consolas, "PingFang SC", "Microsoft YaHei", monospace;

  --r-sm: 8px;
  --r: 14px;
  --r-lg: 20px;
  --gutter: clamp(16px, 4vw, 48px);
  --maxw: 1240px;
  --section-y: clamp(88px, 9vw, 136px);
  --col-gap: clamp(32px, 4.5vw, 64px);
  --ease-out: cubic-bezier(.2, .8, .2, 1);
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-padding-top: 68px; }
p, li, dd { text-wrap: pretty; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 400 16px/1.75 var(--sans);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; }
button { font: inherit; color: inherit; }
code, pre { font-family: var(--mono); }
:focus-visible { outline: 2px solid var(--teal); outline-offset: 3px; border-radius: 4px; }
::selection { background: var(--amber-soft); color: var(--ink); }

.wrap { width: 100%; max-width: calc(var(--maxw) + var(--gutter) * 2); margin: 0 auto; padding: 0 var(--gutter); }
.skip { position: absolute; left: 12px; top: -60px; z-index: 100; background: var(--ink); color: #fff; padding: 8px 14px; border-radius: var(--r-sm); text-decoration: none; }
.skip:focus { top: 12px; }

/* ---------- type ---------- */
.eyebrow {
  margin: 0 0 14px;
  font-size: 13px;
  letter-spacing: .14em;
  color: var(--teal-text);
  font-weight: 600;
  display: flex; align-items: center; gap: 10px;
}
.eyebrow::before { content: ""; width: 22px; height: 1px; background: currentColor; }
.h2 {
  margin: 0;
  font-family: var(--serif);
  font-weight: 900;
  font-size: clamp(32px, 4.2vw, 54px);
  line-height: 1.18;
  letter-spacing: -.01em;
  color: var(--ink);
  font-feature-settings: "palt" 1;
  text-wrap: balance;
}
.h3 { margin: 0 0 10px; font-family: var(--serif); font-weight: 900; font-size: 22px; line-height: 1.35; text-wrap: balance; }
.lead { margin: 18px 0 0; color: var(--ink-2); font-size: 17px; line-height: 1.8; max-width: 34em; }
.note { margin: 28px 0 0; color: var(--muted); font-size: 14px; }
.note a { color: var(--teal-text); text-decoration-thickness: 1px; text-underline-offset: 3px; }
.br-d { display: none; }
.nw { white-space: nowrap; }
@media (min-width: 900px) { .br-d { display: inline; } }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  min-height: 46px; padding: 0 20px;
  border-radius: 999px; border: 1px solid transparent;
  font-size: 15px; font-weight: 600; text-decoration: none; cursor: pointer; white-space: nowrap;
  transition: background-color .2s, border-color .2s, color .2s, transform .2s var(--ease-out);
}
.btn svg { width: 18px; height: 18px; }
.btn:active { transform: translateY(1px) scale(.99); }
.btn--ink { background: var(--ink); color: #fff; }
.btn--ink:hover { background: #1b3a5a; }
.btn--line { border-color: var(--line-strong); background: transparent; color: var(--ink); }
.btn--line:hover { border-color: var(--ink); background: var(--paper-raised); }
.btn--sm { min-height: 40px; padding: 0 16px; font-size: 14px; }

/* ---------- nav ---------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(246, 241, 231, .82);
  backdrop-filter: saturate(1.2) blur(12px);
  -webkit-backdrop-filter: saturate(1.2) blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color .3s, background-color .3s;
}
.nav.is-scrolled { border-bottom-color: var(--line); background: rgba(246, 241, 231, .92); }
.nav__inner { display: flex; align-items: center; gap: 28px; height: 68px; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; flex: none; }
.brand img { width: 30px; height: auto; }
.brand__name { font-weight: 700; font-size: 17px; letter-spacing: -.01em; }
.brand__ver { font: 500 11px/1 var(--mono); color: var(--muted); border: 1px solid var(--line-strong); border-radius: 999px; padding: 4px 7px; }
.nav__links { display: flex; gap: 26px; margin-left: 16px; }
.nav__links a { text-decoration: none; font-size: 14.5px; color: var(--ink-2); position: relative; padding: 6px 0; }
.nav__links a::after { content: ""; position: absolute; left: 0; right: 0; bottom: 0; height: 1.5px; background: var(--ink); transform: scaleX(0); transform-origin: left; transition: transform .25s var(--ease-out); }
.nav__links a:hover { color: var(--ink); }
.nav__links a:hover::after, .nav__links a.is-active::after { transform: scaleX(1); }
.nav__links a.is-active { color: var(--ink); }
.nav__actions { margin-left: auto; display: flex; align-items: center; gap: 10px; }
.gh {
  display: inline-flex; align-items: center; gap: 8px; height: 40px; padding: 0 14px;
  border-radius: 999px; border: 1px solid var(--line-strong); text-decoration: none; font-size: 14px; font-weight: 600;
  transition: border-color .2s, background-color .2s;
}
.gh:hover { border-color: var(--ink); background: var(--paper-raised); }
.gh svg { width: 16px; height: 16px; }
.gh__stars { font: 500 12px/1 var(--mono); color: var(--muted); padding-left: 8px; border-left: 1px solid var(--line-strong); }
.nav__toggle { display: none; width: 42px; height: 42px; border: 1px solid var(--line-strong); border-radius: 999px; background: transparent; cursor: pointer; position: relative; }
.nav__toggle span { position: absolute; left: 12px; right: 12px; height: 1.6px; background: var(--ink); transition: transform .25s var(--ease-out), top .25s; }
.nav__toggle span:first-child { top: 16px; }
.nav__toggle span:last-child { top: 24px; }
.nav__toggle[aria-expanded="true"] span:first-child { top: 20px; transform: rotate(45deg); }
.nav__toggle[aria-expanded="true"] span:last-child { top: 20px; transform: rotate(-45deg); }

@media (max-width: 1020px) {
  .nav__links { display: none; }
  .nav__toggle { display: inline-block; }
  .nav__links.is-open {
    display: flex; flex-direction: column; gap: 0;
    position: absolute; left: 0; right: 0; top: 68px; margin: 0;
    background: var(--paper); border-bottom: 1px solid var(--line);
    padding: 8px var(--gutter) 18px;
    box-shadow: 0 16px 30px -20px rgba(16, 42, 67, .35);
  }
  .nav__links.is-open a { padding: 13px 0; font-size: 16px; border-bottom: 1px solid var(--line); }
  .nav__links.is-open a::after { display: none; }
}
@media (max-width: 560px) {
  .gh span { display: none !important; }
  .gh { padding: 0; width: 40px; justify-content: center; }
  .nav__inner { gap: 12px; }
  .brand__ver { display: none; }
  .nav__actions .btn--sm { padding: 0 14px; }
}

/* ---------- pill ---------- */
.pill {
  display: inline-flex; align-items: center; gap: 8px; margin: 0;
  padding: 6px 14px; border: 1px solid var(--line-strong); border-radius: 999px;
  font-size: 13px; color: var(--ink-2); background: rgba(251, 248, 242, .6);
}
.pill__dot { width: 7px; height: 7px; border-radius: 50%; background: var(--amber); box-shadow: 0 0 0 3px var(--amber-soft); }

/* ---------- hero ---------- */
.hero { padding: clamp(36px, 5vw, 64px) 0 clamp(56px, 6vw, 88px); position: relative; }
.kicker {
  margin: 26px 0 6px;
  font: 600 12.5px/1 var(--sans);
  letter-spacing: .42em; text-transform: uppercase; color: var(--muted);
}
.hero__title {
  margin: 28px 0 0;
  font-family: var(--serif);
  font-weight: 900;
  font-size: clamp(64px, 11.4vw, 164px);
  line-height: 1.04;
  letter-spacing: -.02em;
  color: var(--ink);
  display: flex; flex-wrap: wrap;
  font-feature-settings: "palt" 1;
}
.hero__title .line { display: inline-block; }
.hero__wrap { position: relative; }
.hero__stop { color: var(--teal); }
.hero__band { position: absolute; left: 0; top: 0; width: 100%; height: 100%; pointer-events: none; z-index: 3; overflow: visible; }
.hero__band .band__glow { filter: blur(10px); opacity: .35; }
.hero__band .band__node { fill: #0e2239; stroke: #36c7b1; stroke-width: 2; }
.hero__row {
  display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  gap: 24px var(--col-gap); align-items: end; margin-top: 22px;
}
.hero__lead { margin: 0; font-size: 17px; line-height: 1.85; color: var(--ink-2); max-width: 36em; }
.hero__cta { display: flex; flex-wrap: wrap; gap: 12px; justify-content: flex-end; align-items: center; }
.hero__meta { width: 100%; margin: 6px 0 0; display: flex; justify-content: flex-end; flex-wrap: wrap; gap: 6px 18px; font: 500 12.5px/1.6 var(--mono); color: var(--muted); }
.hero__meta span + span::before { content: "·"; margin-right: 18px; color: var(--line-strong); }
@media (max-width: 900px) { .hero__meta { gap: 4px 16px; } .hero__meta span + span::before { display: none; } }

/* ---------- window (dark carrier) ---------- */
.window {
  background: var(--panel);
  color: var(--panel-text);
  border-radius: var(--r-lg);
  box-shadow: 0 30px 60px -36px rgba(14, 34, 57, .55), 0 2px 0 rgba(255, 255, 255, .04) inset;
  overflow: hidden;
  position: relative;
}
.window__bar {
  display: flex; align-items: center; gap: 14px;
  height: 44px; padding: 0 18px;
  border-bottom: 1px solid var(--panel-line);
  font: 500 12.5px/1 var(--mono); color: var(--panel-muted);
  position: relative; z-index: 2;
}
.window__dots { display: inline-flex; gap: 7px; }
.window__dots i { width: 10px; height: 10px; border-radius: 50%; background: #2a4a69; }
.window__dots i:first-child { background: var(--panel-teal); }
.window__path { color: var(--panel-text); min-width: 0; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.window__tag { margin-left: auto; padding: 5px 10px; border-radius: 999px; background: rgba(54, 199, 177, .12); color: var(--panel-teal); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 60%; }
.window__body { position: relative; }
.v { font-style: normal; color: #8fd3c7; border-bottom: 1px dashed rgba(143, 211, 199, .55); padding-bottom: 1px; }
.hero__window {
  background:
    radial-gradient(120% 90% at 78% 115%, rgba(0, 138, 123, .32), rgba(0, 138, 123, 0) 55%),
    radial-gradient(70% 60% at 8% -10%, rgba(54, 199, 177, .10), rgba(54, 199, 177, 0) 60%),
    var(--panel);
  box-shadow: 0 40px 80px -40px rgba(14, 34, 57, .6), 0 0 0 1px rgba(255, 255, 255, .05) inset, 0 1px 0 rgba(255, 255, 255, .08) inset;
}
.band { position: absolute; left: 0; top: 0; width: 100%; height: 100%; pointer-events: none; z-index: 1; overflow: visible; }
.band .band__front { stroke: url(#bandFront); }
.band .band__glow { filter: blur(10px); opacity: .45; }
.band .band__tick { stroke: #36c7b1; stroke-width: 1.2; stroke-dasharray: 2 4; }
.band .band__node { fill: #0e2239; stroke: #36c7b1; stroke-width: 2; }
.band .band__dot { fill: #f2a51e; }
.tree__row.is-linked { color: #fff; }
.tree__row.is-linked::after { content: ""; position: absolute; left: -14px; right: -14px; top: 3px; bottom: 3px; z-index: -1; border-radius: 6px; background: linear-gradient(90deg, rgba(54, 199, 177, .14), rgba(54, 199, 177, .03) 70%, rgba(54, 199, 177, 0)); }
.tree__row.is-linked .ico--dir, .tree__row.is-linked .ico--dir::before { background: #36c7b1; }

.hero__window { margin-top: clamp(36px, 4vw, 52px); position: relative; z-index: 1; }
.hero__body {
  display: grid; grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
  min-height: 420px;
}
.ribbon { position: absolute; inset: 0; width: 100%; height: 100%; pointer-events: none; z-index: 0; overflow: visible; }

/* tree */
.tree { list-style: none; margin: 0; padding: 24px 28px 28px; position: relative; z-index: 2; font: 400 13.5px/1 var(--mono); }
.tree__row {
  display: flex; align-items: center; gap: 8px;
  height: 29px; white-space: nowrap; color: var(--panel-text); position: relative;
}
.tree__row em { font-style: normal; color: var(--panel-muted); margin-left: 14px; font-size: 12.5px; overflow: hidden; text-overflow: ellipsis; }
.tree__row--root { color: #fff; font-weight: 600; }
.tree__g { color: #5b7c9c; letter-spacing: -.05em; }
.ico { width: 14px; height: 12px; flex: none; position: relative; display: inline-block; }
.ico--dir { border-radius: 2px; background: #3f7fb0; }
.ico--dir::before { content: ""; position: absolute; left: 0; top: -2px; width: 6px; height: 3px; border-radius: 2px 2px 0 0; background: #3f7fb0; }
.ico--file { width: 11px; height: 13px; border: 1.4px solid #6f8ba3; border-radius: 2px; margin: 0 1.5px; }
.tree__row.is-current { color: #fff; }
.tree__row.is-current::before {
  content: ""; position: absolute; left: -14px; right: -14px; top: 2px; bottom: 2px; z-index: -1;
  background: linear-gradient(90deg, rgba(242, 165, 30, .16), rgba(242, 165, 30, 0));
  border-radius: 6px;
}
.beacon { width: 8px; height: 8px; border-radius: 50%; background: var(--amber); margin-left: 10px; box-shadow: 0 0 0 4px rgba(242, 165, 30, .22); animation: beacon 2.4s ease-in-out infinite; }
@keyframes beacon { 50% { box-shadow: 0 0 0 7px rgba(242, 165, 30, .06); } }

/* log */
.log {
  list-style: none; margin: 0; padding: 26px 28px 28px;
  border-left: 1px solid var(--panel-line);
  position: relative; z-index: 2;
  display: flex; flex-direction: column; gap: 10px;
  font: 400 13px/1.6 var(--mono);
  background: transparent;
}
.log__line { color: var(--panel-text); display: flex; gap: 10px; align-items: baseline; }
.log__line--sub { color: var(--panel-muted); padding-left: 52px; margin-top: -6px; }
.log__line--you { color: #fff; padding-bottom: 12px; margin-bottom: 4px; border-bottom: 1px dashed var(--panel-line); font-family: var(--sans); font-size: 14px; }
.log__who { flex: none; font: 600 11px/1 var(--sans); padding: 5px 7px; border-radius: 6px; background: #24425f; color: #cfe0ee; }
.log__tag { flex: none; width: 42px; text-align: center; font: 600 11px/1 var(--sans); padding: 5px 0; border-radius: 6px; background: rgba(54, 199, 177, .14); color: var(--panel-teal); }
.log__tag--go { background: var(--amber); color: #3b2604; }
.caret { display: inline-block; width: 7px; height: 14px; margin-left: 6px; background: var(--panel-teal); vertical-align: -2px; animation: caret 1.1s steps(1) infinite; }
@keyframes caret { 50% { opacity: 0; } }

/* ---------- section scaffolding ---------- */
.section { padding: var(--section-y) 0; position: relative; }
.section + .section { border-top: 1px solid var(--line); }
.sec-head { display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); gap: 24px var(--col-gap); align-items: end; margin-bottom: clamp(36px, 4vw, 56px); }
.sec-head .lead { margin: 0; }
.eyebrow__path { font: 500 12px/1 var(--mono); letter-spacing: 0; color: var(--muted); padding: 4px 8px; border: 1px solid var(--line-strong); border-radius: 6px; background: rgba(251, 248, 242, .7); }

/* the project tree keeps running down the page as a spine */
@media (min-width: 1000px) {
  .spine .wrap { position: relative; }
  .spine .wrap::before {
    content: ""; position: absolute; top: calc(var(--section-y) * -1); bottom: calc(var(--section-y) * -1);
    left: calc(var(--gutter) - 30px); border-left: 1.5px dashed #b9ad96;
  }
  .how.spine .wrap::before { top: -40vh; bottom: -40vh; }
  .spine--end .wrap::before { bottom: auto; height: calc(var(--section-y) + 11px); }
  .spine--end .eyebrow::after { background: var(--teal); }
  .spine .eyebrow::before { width: 52px; margin-left: -30px; background: #b9ad96; }
  .spine .eyebrow { position: relative; }
  .spine .eyebrow::after { content: ""; position: absolute; left: -34px; top: 50%; width: 9px; height: 9px; margin-top: -4.5px; border-radius: 50%; background: var(--paper); border: 1.5px solid var(--teal); }
}

/* ---------- how (pinned narrative) ---------- */
.how { border-top: 1px solid var(--line); background: linear-gradient(180deg, var(--paper) 0%, var(--paper-sunk) 100%); }
.how__pin { min-height: 100vh; display: flex; align-items: center; padding: clamp(72px, 8vw, 110px) 0; }
.how__grid { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); gap: 32px var(--col-gap); align-items: center; }
.how__text { position: relative; }
.steps { list-style: none; margin: 34px 0 0; padding: 0 0 0 0; display: grid; gap: 6px; position: relative; }
.step { display: grid; grid-template-columns: 44px 1fr; gap: 14px; padding: 14px 0; transition: opacity .3s; }
.step__n { font: 600 13px/1 var(--mono); color: var(--teal-text); padding-top: 6px; position: relative; z-index: 1; }
.step__n::before { content: ""; position: absolute; left: -1px; top: 2px; width: 30px; height: 20px; border-radius: 999px; background: var(--paper); z-index: -1; }
.step h3 { margin: 0 0 4px; font-family: var(--serif); font-weight: 900; font-size: 21px; }
.step p { margin: 0; color: var(--ink-2); font-size: 15px; line-height: 1.75; }
.steps__rail { display: none; }

.how__window { width: 100%; }
.how__view { height: min(62vh, 520px); min-height: 380px; overflow: hidden; }
.how__cam { transform-origin: 0 0; padding: 22px 30px; will-change: transform; }
.how__cam .tree__row { transition: none; }
.how__marker {
  position: absolute; left: 12px; right: 12px; top: 0; height: 29px; z-index: 0;
  border-radius: 7px; pointer-events: none;
  background: linear-gradient(90deg, rgba(242, 165, 30, .22), rgba(242, 165, 30, .02));
  border-left: 3px solid var(--amber);
  opacity: 0;
}
.tag { font: 500 11px/1 var(--mono) !important; padding: 4px 8px; border-radius: 999px; margin-left: 14px; }
.tag--teal { background: rgba(54, 199, 177, .14); color: var(--panel-teal) !important; }
.badge-new { font: 700 12px/1 var(--sans) !important; color: #3b2604 !important; background: var(--amber); padding: 4px 8px; border-radius: 999px; }

/* static layout (no JS / reduced motion) shows every step */
.how .step { opacity: 1; }
.how.is-static .how__view { height: auto; min-height: 0; }
.how.is-static .how__marker { display: none; }
.how.is-static .badge-new { opacity: 1; }

/* pinned narrative */
.how.is-pinned .step { opacity: .34; }
.how.is-pinned .step.is-active { opacity: 1; }
.how.is-pinned .step.is-active .step__n { color: #fff; }
.how.is-pinned .step.is-active .step__n::before { background: var(--ink); }
.how.is-pinned .steps__rail {
  display: block; position: absolute; left: 14px; width: 1.5px; bottom: 30px;
  top: var(--rail-top, 52%); background: var(--line-strong);
}
.how.is-pinned .steps__rail i { position: absolute; inset: 0; background: var(--teal); transform-origin: 0 0; transform: scaleY(0); }
.how.is-pinned .step__n { padding-left: 1px; }
@media (max-width: 900px) {
  .how.is-pinned .how__pin { padding: 76px 0 24px; align-items: flex-start; }
  .how.is-pinned .how__grid { gap: 18px; }
  .how.is-pinned .lead { display: none; }
  .how.is-pinned .h2 { font-size: clamp(28px, 7.4vw, 40px); }
  .how.is-pinned .steps { margin-top: 18px; display: grid; }
  .how.is-pinned .step { grid-area: 1 / 1; opacity: 0; padding: 0; }
  .how.is-pinned .step.is-active { opacity: 1; }
  .how.is-pinned .steps__rail { display: none; }
  .how.is-pinned .how__view { height: min(46vh, 420px); min-height: 280px; }
}

/* ---------- loop map ---------- */
.loop__grid { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); gap: 40px var(--col-gap); align-items: start; }
.loop__side { display: grid; gap: 30px; align-content: start; }
.loop.section { padding-top: clamp(72px, 7vw, 100px); padding-bottom: clamp(72px, 7vw, 100px); }
.cycle { max-height: 540px; }
.cycle__port rect { fill: var(--amber-soft); stroke: #c9820a; stroke-width: 1.5; }
.cycle__port text { font: 700 14px/1 var(--serif); fill: var(--amber-text); text-anchor: middle; dominant-baseline: middle; }
.cycle__port { opacity: 0; transition: opacity .25s; }
.cycle__port.is-on { opacity: 1; }
.cycle__back .cycle__port text { opacity: 1; stroke: none; }
.loop__map { min-width: 0; }
.cycle { width: 100%; height: auto; display: block; color: var(--teal); overflow: visible; }
.cycle__track { fill: none; stroke: var(--line); stroke-width: 1; stroke-dasharray: 2 6; }
.cycle__arcs path { fill: none; stroke: var(--teal); stroke-width: 1.6; }
.cycle__back path { fill: none; stroke: #c9820a; stroke-width: 1.8; stroke-linejoin: round; opacity: 0; }
.cycle__back path.is-on { opacity: 1; }
.cycle__back text { font: 700 12px/1 var(--sans); fill: var(--amber-text); paint-order: stroke; stroke: var(--paper); stroke-width: 5px; stroke-linejoin: round; opacity: 0; text-anchor: middle; dominant-baseline: middle; }
.cycle__back text.is-on { opacity: 1; }
.node { cursor: pointer; outline: none; }
.node circle { fill: var(--paper-raised); stroke: var(--line-strong); stroke-width: 1.2; transition: fill .2s, stroke .2s; }
.node text { font: 700 16px/1 var(--serif); fill: var(--ink); text-anchor: middle; dominant-baseline: middle; pointer-events: none; }
.node .node__sub { font: 500 9.5px/1 var(--mono); fill: var(--muted); }
.node:hover circle, .node:focus-visible circle { stroke: var(--teal); }
.node:focus-visible circle, .node--hub:focus-visible rect { stroke-width: 2.4; }
.node.is-active circle { fill: var(--ink); stroke: var(--ink); }
.node.is-active text { fill: #fff; }
.node.is-active .node__sub { fill: #a9c0d3; }
.node.is-target circle { stroke: #c9820a; stroke-width: 2; fill: var(--amber-soft); }
.node--hub rect { fill: var(--teal-soft); stroke: #a8d6cb; stroke-width: 1.2; transition: fill .2s, stroke .2s; }
.node--hub text { font: 600 13px/1 var(--mono); fill: var(--teal-text); dominant-baseline: auto; }
.node--hub:hover rect { stroke: var(--teal); }
.node--hub.is-active rect { fill: var(--teal); stroke: var(--teal); }
.node--hub.is-active text { fill: #fff; }

.lanes { margin-top: 18px; display: grid; gap: 12px; }
.lane { display: grid; grid-template-columns: 1fr; gap: 8px; padding-top: 12px; border-top: 1px solid var(--line); }
.lane__label { font-size: 12.5px; color: var(--muted); }
.lane__chips { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.lane__group { display: inline-flex; align-items: center; gap: 8px; white-space: nowrap; }
.lane__arr { color: var(--teal); font-size: 14px; }
.chip {
  border: 1px solid var(--line-strong); background: var(--paper-raised); border-radius: 999px;
  min-height: 36px; padding: 0 14px; font-family: var(--serif); font-weight: 700; font-size: 14.5px; cursor: pointer;
  transition: border-color .2s, background-color .2s, color .2s;
}
@media (hover: hover) { .chip:hover { border-color: var(--teal); } }
.chip.is-active { background: var(--ink); border-color: var(--ink); color: #fff; }
.chip.is-target { border-color: #c9820a; background: var(--amber-soft); }

.detail { border-top: 1.5px solid var(--ink); padding-top: 22px; }
.detail__group { margin: 0 0 10px; font-size: 12.5px; color: var(--teal-text); letter-spacing: .1em; font-weight: 600; }
.detail__title { margin: 0 0 12px; font-family: var(--serif); font-weight: 900; font-size: 28px; line-height: 1.25; display: flex; flex-wrap: wrap; align-items: baseline; gap: 4px 12px; }
.detail__title code { font: 500 13px/1.4 var(--mono); color: var(--muted); }
.detail__desc { margin: 0; color: var(--ink-2); font-size: 15px; line-height: 1.8; }
.detail__dl { margin: 18px 0 0; display: grid; gap: 0; border-top: 1px solid var(--line); }
.detail__dl > div { display: grid; grid-template-columns: 72px 1fr; gap: 12px; padding: 12px 0; border-bottom: 1px solid var(--line); align-items: baseline; }
.detail__dl dt { font-size: 12.5px; color: var(--muted); }
.detail__dl dd { margin: 0; font-size: 14px; }
.detail__dl code { font-size: 12.5px; color: var(--ink); word-break: break-all; }
.detail__chips { display: flex; flex-wrap: wrap; gap: 6px; }
.detail__chips button { border: 1px solid #e0b25d; background: var(--amber-soft); color: var(--amber-text); border-radius: 999px; padding: 3px 11px; font-size: 13px; cursor: pointer; }
.detail__chips button.is-next { border-color: #a8d6cb; background: var(--teal-soft); color: var(--teal-text); }
.detail__chips span { color: var(--muted); font-size: 13.5px; }
.detail__links { display: flex; flex-wrap: wrap; gap: 8px 22px; margin: 16px 0 0; }
.detail__link { display: inline-block; font-size: 14px; color: var(--teal-text); text-decoration: underline; text-underline-offset: 3px; text-decoration-thickness: 1px; }
.detail__link--btn { border: 0; background: none; padding: 0; cursor: pointer; font: inherit; font-size: 14px; color: var(--teal-text); }

/* ---------- skills ledger ---------- */
.filters { display: flex; flex-wrap: wrap; gap: 4px 26px; margin-bottom: 4px; }
.filter {
  border: 0; border-bottom: 2px solid transparent; background: transparent; border-radius: 0;
  min-height: 44px; padding: 0 0 2px; font-family: var(--serif); font-weight: 700; font-size: 16px; cursor: pointer; color: var(--muted);
  transition: color .2s, border-color .2s;
}
.filter span { font: 500 11px/1 var(--mono); color: var(--muted); margin-left: 5px; vertical-align: super; }
@media (hover: hover) { .filter:hover { color: var(--ink); } }
.filter[aria-pressed="true"] { color: var(--ink); border-bottom-color: var(--ink); }
.filter[aria-pressed="true"] span { color: var(--teal-text); }

.ledger { border-top: 1.5px solid var(--ink); }
.ledger__head, .lrow {
  display: grid; grid-template-columns: 48px minmax(190px, 1.05fr) minmax(0, 2fr) minmax(170px, 1.05fr) 96px;
  gap: 20px; align-items: center;
}
.ledger__head { padding: 12px 0; font-size: 12.5px; color: var(--muted); border-bottom: 1px solid var(--line); }
.lrow { padding: 16px 0; border-bottom: 1px solid var(--line); transition: background-color .2s; }
.lrow:hover { background: linear-gradient(90deg, rgba(255, 255, 255, 0), rgba(251, 248, 242, .9) 12%, rgba(251, 248, 242, .9) 88%, rgba(255, 255, 255, 0)); }
.lrow[hidden] { display: none; }
.lrow__n { font: 500 12.5px/1 var(--mono); color: var(--muted); }
.lrow__name { font: 600 14.5px/1.4 var(--mono); color: var(--ink); text-decoration: none; display: inline-flex; flex-direction: column; gap: 3px; }
.lrow__name small { font: 400 12.5px/1.3 var(--sans); color: var(--muted); }
.lrow__name:hover span { text-decoration: underline; text-underline-offset: 3px; text-decoration-thickness: 1px; }
.lrow__desc { color: var(--ink-2); font-size: 14.5px; line-height: 1.7; }
.lrow__out { font: 400 12.5px/1.6 var(--mono); color: var(--teal-text); word-break: break-word; }
.cat { justify-self: start; font-size: 12px; padding: 4px 10px; border-radius: 999px; border: 1px solid var(--line-strong); color: var(--ink-2); white-space: nowrap; }
.cat--coord { background: var(--ink); color: #fff; border-color: var(--ink); }
.cat--research { background: var(--teal-soft); border-color: #a8d6cb; color: var(--teal-text); }
.cat--paper { background: #e8edf3; border-color: #c7d3df; color: #2d4a66; }
.cat--ondemand { background: var(--amber-soft); border-color: #e9c98a; color: var(--amber-text); }
.cat--diagram { background: transparent; }

/* ---------- gallery ---------- */
.charts__head { margin-bottom: clamp(36px, 4vw, 56px); max-width: 980px; }
.h2--wide { font-size: clamp(36px, 6vw, 84px); line-height: 1.08; }
.charts__head .lead { max-width: 40em; }
.gallery { display: flex; gap: 22px; align-items: flex-start; }
.gallery__col { flex: 1 1 0; min-width: 0; }
.fig {
  break-inside: avoid; margin: 0 0 22px; display: block;
  background: var(--paper-raised); border: 1px solid var(--line); border-radius: var(--r);
  overflow: hidden; transition: border-color .25s, box-shadow .25s, transform .3s var(--ease-out);
}
.fig:hover { border-color: var(--line-strong); box-shadow: 0 18px 36px -26px rgba(16, 42, 67, .35); }
.fig__img { display: block; width: 100%; padding: 14px 14px 0; border: 0; background: #fff; cursor: zoom-in; overflow: hidden; }
.fig__img img { width: 100%; height: auto; transition: transform .6s var(--ease-out); }
.fig:hover .fig__img img { transform: scale(1.015); }
.fig__cap { padding: 16px 18px 18px; border-top: 1px solid var(--line); }
.fig__top { display: flex; align-items: baseline; gap: 10px; }
.fig__n { font: 600 12px/1 var(--mono); color: var(--teal-text); }
.fig__title { margin: 0; font-family: var(--serif); font-weight: 900; font-size: 17px; line-height: 1.4; }
.fig__cat { margin: 6px 0 0; font-size: 12.5px; color: var(--muted); }
.fig__sum { margin: 8px 0 0; font-size: 13.5px; line-height: 1.7; color: var(--ink-2); }
.fig__src { display: inline-flex; margin-top: 10px; font: 500 12px/1.4 var(--mono); color: var(--teal-text); text-decoration: none; border-bottom: 1px solid #a8d6cb; padding-bottom: 1px; }
.fig__src:hover { border-bottom-color: var(--teal); }

/* ---------- methods compare ---------- */
.methods__grid { display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); gap: 32px var(--col-gap); align-items: center; }
.methods__side .lead { margin-bottom: 26px; }
.tabs { display: inline-flex; gap: 4px; padding: 4px; border: 1px solid var(--line-strong); border-radius: 999px; margin-bottom: 22px; background: var(--paper-raised); }
.tab { border: 0; background: transparent; border-radius: 999px; min-height: 38px; padding: 0 18px; font-size: 14.5px; font-weight: 600; cursor: pointer; color: var(--ink-2); transition: background-color .2s, color .2s; }
.tab:hover { color: var(--ink); }
.tab[aria-selected="true"] { background: var(--ink); color: #fff; }
.compare__info .h3 { margin-top: 4px; }
.methods > .wrap > .eyebrow { margin-bottom: 22px; }
.compare__labels { display: flex; justify-content: space-between; margin-bottom: 10px; font-size: 13px; font-weight: 600; color: var(--ink-2); }
.compare__labels span:last-child { color: var(--ink); }
.compare {
  position: relative; aspect-ratio: 3 / 2; border-radius: var(--r); overflow: hidden;
  background: #fff; border: 1px solid var(--line); touch-action: pan-y; user-select: none;
}
.compare__img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: contain; background: #fff; }
.compare__img--ref { clip-path: inset(0 calc(100% - var(--pos)) 0 0); }
.compare__label { position: absolute; bottom: 14px; z-index: 3; font-size: 12.5px; font-weight: 600; padding: 6px 11px; border-radius: 999px; pointer-events: none; }
.compare__label--l { left: 14px; background: rgba(251, 248, 242, .92); color: var(--ink); border: 1px solid var(--line); }
.compare__label--r { right: 14px; background: var(--ink); color: #fff; }
.compare__handle { position: absolute; top: 0; bottom: 0; left: var(--pos); width: 0; z-index: 2; pointer-events: none; }
.compare__handle::before { content: ""; position: absolute; top: 0; bottom: 0; left: -1px; width: 2px; background: var(--ink); }
.compare__handle i {
  position: absolute; top: 50%; left: 0; width: 42px; height: 42px; transform: translate(-50%, -50%);
  border-radius: 50%; background: var(--paper-raised); border: 2px solid var(--ink);
  box-shadow: 0 6px 16px -6px rgba(16, 42, 67, .5);
}
.compare__handle i::before, .compare__handle i::after { content: ""; position: absolute; top: 50%; width: 7px; height: 7px; border-top: 2px solid var(--ink); border-left: 2px solid var(--ink); }
.compare__handle i::before { left: 9px; transform: translateY(-50%) rotate(-45deg); }
.compare__handle i::after { right: 9px; transform: translateY(-50%) rotate(135deg); }
.compare__range { position: absolute; inset: 0; width: 100%; height: 100%; margin: 0; opacity: 0; cursor: ew-resize; z-index: 4; }
.compare__range:focus-visible + .compare__handle i, .compare:focus-within .compare__handle i { outline: 2px solid var(--teal); outline-offset: 3px; }
.compare__info p:not(.eyebrow) { margin: 0; color: var(--ink-2); font-size: 15px; line-height: 1.8; }
.spec { margin: 20px 0 22px; border-top: 1px solid var(--line); }
.spec > div { display: grid; grid-template-columns: 64px 1fr; gap: 12px; padding: 12px 0; border-bottom: 1px solid var(--line); }
.spec dt { font-size: 12.5px; color: var(--muted); }
.spec dd { margin: 0; font-size: 14px; color: var(--ink); }

/* ---------- install ---------- */
.install__grid { display: grid; grid-template-columns: minmax(0, 1fr); gap: 28px; align-items: start; }
.install__text { max-width: 760px; }
.install__text .h2 { font-size: clamp(32px, 4.6vw, 60px); }
.terminal {
  position: relative; background: var(--panel); color: var(--panel-text);
  border-radius: var(--r-lg); padding: 10px 10px 20px; overflow: hidden;
  box-shadow: 0 30px 60px -36px rgba(14, 34, 57, .55);
}
.ribbon--term { opacity: .9; }
.terminal__tabs { position: relative; z-index: 1; display: flex; flex-wrap: wrap; gap: 4px; padding: 4px; border-bottom: 1px solid var(--panel-line); }
.ttab { border: 0; background: transparent; color: var(--panel-muted); border-radius: 10px; min-height: 38px; padding: 0 14px; font-size: 13.5px; font-weight: 600; cursor: pointer; transition: background-color .2s, color .2s; }
.ttab:hover { color: var(--panel-text); }
.ttab[aria-selected="true"] { background: var(--paper-raised); color: var(--ink); }
.terminal__panel { position: relative; z-index: 1; padding: 20px 18px 6px; display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 16px; align-items: start; }
.terminal__panel[hidden] { display: none; }
.terminal pre { margin: 0; font-size: 14px; line-height: 1.85; white-space: pre-wrap; word-break: break-word; color: #f2f6fa; }
.terminal .ps { color: var(--panel-teal); user-select: none; }
.copy {
  display: inline-flex; align-items: center; gap: 6px;
  border: 1px solid #3b5a78; background: rgba(14, 34, 57, .6); color: var(--panel-text);
  border-radius: 999px; min-height: 36px; padding: 0 14px; font-size: 13px; font-weight: 600; cursor: pointer;
  transition: border-color .2s, background-color .2s;
}
.copy:hover { border-color: var(--panel-teal); }
.copy.is-done { border-color: var(--panel-teal); color: var(--panel-teal); }
.copy.is-fail { border-color: #f3c56b; color: #f3c56b; }
.copy--light.is-fail { border-color: #c9820a; color: var(--amber-text); }
.copy--light { border-color: var(--line-strong); background: var(--paper-raised); color: var(--ink); }
.copy--light:hover { border-color: var(--ink); }
.copy--light.is-done { border-color: var(--teal); color: var(--teal-text); }
.terminal__note { grid-column: 1 / -1; margin: 2px 0 0; padding-top: 14px; border-top: 1px dashed var(--panel-line); font-size: 13.5px; color: var(--panel-muted); line-height: 1.75; }
.terminal__note strong { color: #f3c56b; font-weight: 600; }
.terminal__note code { color: var(--panel-text); background: rgba(255, 255, 255, .06); padding: 1px 6px; border-radius: 5px; }

.start { grid-column: 1 / -1; margin-top: clamp(16px, 2vw, 28px); }
.start__hint { margin: 4px 0 0; }
mark.slot { background: var(--amber-soft); color: var(--amber-text); border-radius: 4px; padding: 0 3px; }
.start__grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; margin-top: 16px; }
.prompt { margin: 0; position: relative; border-top: 1.5px solid var(--ink); padding: 16px 0 0; display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 12px 14px; align-items: center; }
.prompt figcaption { font-size: 13px; color: var(--teal-text); font-weight: 600; letter-spacing: .08em; }
.prompt .copy { grid-column: 2; grid-row: 1; align-self: center; height: 36px; }
.prompt pre { grid-column: 1 / -1; margin: 0; font: 400 13.5px/1.85 var(--mono); color: var(--ink); white-space: pre-wrap; word-break: break-word; }

/* ---------- support ---------- */
.support__grid { display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); gap: 36px var(--col-gap); align-items: center; }
.contact { list-style: none; margin: 26px 0 0; padding: 0; border-top: 1px solid var(--line); }
.contact li { border-bottom: 1px solid var(--line); }
.contact a { display: flex; justify-content: space-between; padding: 14px 0; text-decoration: none; font-size: 15.5px; color: var(--ink); transition: color .2s, padding .25s var(--ease-out); }
.contact a:hover { color: var(--teal-text); padding-left: 6px; }
.related { margin: 18px 0 0; font-size: 14px; color: var(--muted); }
.related a { color: var(--ink); text-underline-offset: 3px; }
.qrs { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; }
.qr { margin: 0; text-align: left; }
.qr img { width: 100%; aspect-ratio: 1; object-fit: contain; border-radius: 10px; background: #fff; padding: 6px; box-shadow: 0 0 0 1px var(--line); }
.qr figcaption { margin-top: 10px; font-size: 13.5px; color: var(--ink-2); font-weight: 600; padding-left: 2px; }

/* ---------- footer ---------- */
.footer { border-top: 1px solid var(--line); padding: clamp(56px, 7vw, 96px) 0 40px; background: var(--paper-sunk); overflow: hidden; }
.footer__mark { position: relative; max-width: 760px; }
.footer__mark img { position: relative; z-index: 1; width: 100%; height: auto; }
.ribbon--foot { left: 96%; width: 100vw; height: 120%; top: -10%; opacity: .8; }
.footer__cols { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 24px; margin-top: 48px; padding-top: 28px; border-top: 1px solid var(--line-strong); max-width: 760px; }
.footer__cols h4 { margin: 0 0 10px; font-size: 12.5px; color: var(--muted); font-weight: 600; letter-spacing: .1em; }
.footer__cols a { display: block; padding: 5px 0; font-size: 14.5px; color: var(--ink); text-decoration: none; }
.footer__cols a:hover { color: var(--teal-text); }
.footer__legal { margin: 36px 0 0; font-size: 13px; color: var(--muted); max-width: 52em; line-height: 1.8; }

/* ---------- lightbox ---------- */
.lightbox { width: min(1280px, 96vw); max-height: 94vh; padding: 0; border: 0; border-radius: var(--r-lg); background: var(--paper-raised); color: var(--ink); box-shadow: 0 40px 80px -30px rgba(0, 0, 0, .5); }
.lightbox::backdrop { background: rgba(14, 34, 57, .72); backdrop-filter: blur(3px); }
.lightbox[open] { display: flex; flex-direction: column; }
.lightbox__bar { display: flex; justify-content: space-between; align-items: center; padding: 12px 16px; border-bottom: 1px solid var(--line); margin: 0; }
.lightbox__count { font: 500 12.5px/1 var(--mono); color: var(--muted); }
.lightbox__close { border: 1px solid var(--line-strong); background: transparent; border-radius: 999px; min-height: 36px; padding: 0 14px; font-size: 13.5px; cursor: pointer; }
.lightbox__close:hover { border-color: var(--ink); }
.lightbox__stage { position: relative; flex: 1; min-height: 0; display: flex; align-items: center; justify-content: center; background: #fff; padding: 12px 56px; }
.lightbox__stage img { max-width: 100%; max-height: calc(94vh - 190px); width: auto; height: auto; object-fit: contain; }
.lightbox__nav { position: absolute; top: 50%; transform: translateY(-50%); width: 44px; height: 44px; border-radius: 50%; border: 1px solid var(--line-strong); background: var(--paper-raised); font-size: 24px; line-height: 1; cursor: pointer; }
.lightbox__nav:hover { border-color: var(--ink); }
.lightbox__nav--prev { left: 8px; }
.lightbox__nav--next { right: 8px; }
.lightbox__nav[hidden] { display: none; }
.lightbox__cap { padding: 14px 20px 18px; border-top: 1px solid var(--line); font-size: 14px; color: var(--ink-2); line-height: 1.7; }
.lightbox__cap strong { font-family: var(--serif); color: var(--ink); margin-right: 8px; }
.lightbox__cap a { color: var(--teal-text); }
.lightbox__cap small { display: block; color: var(--muted); font-size: 12.5px; margin-top: 4px; }

/* ---------- toast ---------- */
.toast { position: fixed; left: 50%; bottom: 28px; transform: translate(-50%, 16px); z-index: 80; background: var(--ink); color: #fff; padding: 10px 18px; border-radius: 999px; font-size: 14px; opacity: 0; pointer-events: none; transition: opacity .25s, transform .25s var(--ease-out); }
.toast.is-on { opacity: 1; transform: translate(-50%, 0); }

/* ---------- reveal (JS adds .js on <html>) ---------- */
.js .reveal { opacity: 0; transform: translateY(18px); }

/* ---------- responsive ---------- */
@media (max-width: 1100px) {
  .ledger__head, .lrow { grid-template-columns: 40px minmax(170px, 1fr) minmax(0, 1.8fr) minmax(150px, 1fr); }
  .ledger__head span:last-child, .lrow .cat { display: none; }
}
@media (max-width: 900px) {
  .hero__row { grid-template-columns: 1fr; gap: 22px; }
  .hero__cta { justify-content: flex-start; }
  .hero__meta { justify-content: flex-start; }
  .hero__body { grid-template-columns: 1fr; min-height: 0; }
  .log { border-left: 0; border-top: 1px solid var(--panel-line); }
  .sec-head { grid-template-columns: 1fr; }
  .sec-head .lead { justify-self: start; }
  .how__grid { grid-template-columns: 1fr; }
  .methods__grid { grid-template-columns: 1fr; }
  .loop__grid { grid-template-columns: 1fr; }
  .loop__map { max-width: 620px; }
  .install__grid { grid-template-columns: 1fr; }
  .support__grid { grid-template-columns: 1fr; }
  .start__grid { grid-template-columns: 1fr; }
}
@media (max-width: 720px) {
  .chip { padding: 0 11px; font-size: 14px; }
  .node text { font-size: 23px; }
  .node .node__sub { display: none; }
  .node--hub text { font-size: 18px; }
  .cycle__back text, .cycle__port text { font-size: 19px; stroke-width: 6px; }
  .lane__chips, .lane__group { gap: 6px; }
  .ledger { border-top-width: 1px; }
  .ledger__head { display: none; }
  .lrow { grid-template-columns: 34px 1fr; gap: 6px 10px; padding: 16px 0; }
  .lrow__n { grid-row: 1 / span 3; padding-top: 4px; }
  .lrow__desc, .lrow__out { grid-column: 2; }
  .tree { padding: 18px 18px 20px; font-size: 12.5px; }
  .tree__row { height: 27px; }
  .tree__row em { display: none; }
  .tree__row em.badge-new, .tree__row em.tag { display: inline-block; margin-left: 10px; }
  .log { padding: 20px 18px 22px; font-size: 12.5px; }
  .log__line--sub { padding-left: 52px; }
  .footer__cols { grid-template-columns: 1fr 1fr; }
  .lane { grid-template-columns: 1fr; gap: 8px; }
  .qrs { gap: 10px; }
  .qr { padding: 10px 10px 8px; }
  .qr figcaption { font-size: 12.5px; }
  .lightbox__stage { padding: 10px 8px 56px; }
  .lightbox__nav { top: auto; bottom: 8px; transform: none; }
  .lightbox__nav--prev { left: calc(50% - 52px); }
  .lightbox__nav--next { right: calc(50% - 52px); }
}
@media (max-width: 560px) {
  .hero__title { font-size: 19.5vw; line-height: 1.06; flex-direction: column; }
  .hero__lead { font-size: 16px; }
  .hero__cta .btn { flex: 1 1 auto; }
  .lead { font-size: 16px; }
  .how__view { height: 46vh; min-height: 300px; }
  .how__cam { padding: 16px 18px; }
  .tabs { display: flex; width: 100%; }
  .tab { flex: 1; padding: 0 8px; }
  .terminal__panel { grid-template-columns: 1fr; }
  .terminal__panel .copy { justify-self: start; }
  .terminal pre { font-size: 12.5px; }
  .ttab { padding: 0 9px; font-size: 12.5px; }
  .how .window__path { display: none; }
  .tree__row em.tag { display: none; }
  .compare__label { bottom: 10px; font-size: 11.5px; padding: 5px 9px; }
  .compare__label--l { left: 10px; }
  .compare__label--r { right: 10px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
  .js .reveal { opacity: 1; transform: none; }
}

/* ---------- language switch ---------- */
.lang {
  display: inline-flex; align-items: center; justify-content: center; height: 40px; min-width: 40px; padding: 0 12px;
  border-radius: 999px; border: 1px solid var(--line-strong); text-decoration: none; font-size: 13.5px; font-weight: 600; color: var(--ink-2);
  transition: border-color .2s, background-color .2s, color .2s;
}
.lang:hover { border-color: var(--ink); color: var(--ink); background: var(--paper-raised); }
@media (max-width: 560px) { .lang { padding: 0 10px; } }
@media (max-width: 430px) { .gh { display: none; } }

/* ---------- English page ---------- */
html[lang="en"] {
  --serif: "Source Serif 4", "Source Serif Pro", "Noto Serif", Georgia, "Times New Roman", serif;
}
html[lang="en"] body { line-height: 1.65; }
html[lang="en"] .hero__title { font-size: clamp(52px, 8.2vw, 124px); letter-spacing: -.035em; line-height: 1.02; font-weight: 800; }
html[lang="en"] .h2 { letter-spacing: -.02em; font-weight: 800; }
html[lang="en"] .h2--wide { font-size: clamp(36px, 5.6vw, 78px); }
html[lang="en"] .eyebrow { letter-spacing: .08em; text-transform: uppercase; font-size: 12px; }
html[lang="en"] .eyebrow__path { text-transform: none; }
html[lang="en"] .log__tag { width: 58px; }
html[lang="en"] .log__line--sub { padding-left: 68px; }
html[lang="en"] .node text { font-size: 14px; }
html[lang="en"] .node .node__sub { font-size: 9.5px; }
html[lang="en"] .cycle__back text, html[lang="en"] .cycle__port text { font-size: 12px; }
html[lang="en"] .chip, html[lang="en"] .filter { font-weight: 700; }
html[lang="en"] .step h3, html[lang="en"] .fig__title, html[lang="en"] .detail__title { font-weight: 800; }
html[lang="en"] .lane__label { letter-spacing: .02em; }
@media (max-width: 720px) {
  html[lang="en"] .node text { font-size: 15px; }
  html[lang="en"] .cycle__back text, html[lang="en"] .cycle__port text { font-size: 17px; }
}
@media (max-width: 560px) {
  html[lang="en"] .hero__title { font-size: 15.5vw; }
}