:root {
  color-scheme: dark;
  --base: #080b10;
  --surface: #101720;
  --line: #2a3748;
  --text: #f1f5fb;
  --muted: #afbdce;
  --accent: #a3d2ff;
  font-family: system-ui, "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.65;
  background: var(--base);
  color: var(--text);
}
*, *::before, *::after { box-sizing: border-box; }
body { margin: 0; }
a { color: var(--accent); text-underline-offset: .25em; }
a:hover { color: #fff; }
:focus-visible { outline: 2px solid #bfe4ff; outline-offset: 4px; }
p { margin: .5rem 0 1.2rem; color: var(--muted); }
h1, h2, h3 { margin: 0; line-height: 1.23; }
h2 { font-size: clamp(1.35rem, 3vw, 2rem); }
.skip { position: fixed; left: 1rem; top: .5rem; transform: translateY(-160%); z-index: 10; background: var(--surface); padding: .6rem; }
.skip:focus { transform: none; }
.wrap, .mast-inner, .hero-inner, .site-foot { width: min(100% - 4rem, 1200px); margin-inline: auto; }
.mast { position: relative; z-index: 1; border-bottom: 1px solid #202a37; background: #0a0e15; }
.mast-inner { display: flex; align-items: center; justify-content: space-between; gap: 1.5rem; min-height: 66px; }
.brand { font-size: 1.1rem; font-weight: 780; letter-spacing: .025em; color: var(--text); text-decoration: none; white-space: nowrap; }
.mast nav, .site-foot nav { display: flex; align-items: center; gap: clamp(.75rem, 2.6vw, 2rem); flex-wrap: wrap; }
.mast nav a, .mast nav span, .site-foot nav a, .site-foot nav span { font-size: .87rem; font-weight: 550; color: var(--muted); text-decoration: none; padding-block: .45rem; }
.mast nav a:hover, .mast nav [aria-current] { color: #fff; }
.orbital { position: relative; min-height: 520px; overflow: clip; isolation: isolate; background: radial-gradient(ellipse at 78% 48%, #131f30 0%, #070a0f 62%); }
.earth-frame { position: absolute; z-index: -1; inset: 0 0 0 auto; width: min(80vw, 1000px); aspect-ratio: 3 / 2; margin-block: auto; max-height: 100%; overflow: hidden; }
.earth-frame::after { content: ""; position: absolute; inset: 0; background: linear-gradient(90deg, #080b10 0%, transparent 32%), linear-gradient(0deg, #080b10 0%, transparent 12%); pointer-events: none; }
.earth-image { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: fill; }
.earth-image[data-earth-src]:not([data-ready]) { visibility: hidden; }
.earth-flow { position: absolute; inset: 0; pointer-events: none; }
.earth-flow span { position: absolute; display: block; width: 5px; height: 5px; border-radius: 50%; opacity: 0; background: #eff9ff; box-shadow: 0 0 7px 4px #79bdfa, 0 0 19px 7px #4286ee88; transform: translate(-50%, -50%); }
.hero-inner { display: flex; min-height: inherit; flex-direction: column; justify-content: center; align-items: flex-start; padding-block: 3.25rem; }
.overline, .micro { color: var(--accent); font-size: .75rem; font-weight: 690; letter-spacing: .14em; }
.overline { margin: 0 0 .65rem; }
.hero-inner h1 { font-size: clamp(2.4rem, 6.1vw, 5rem); letter-spacing: -.062em; font-weight: 790; text-wrap: balance; text-shadow: 0 2px 18px #05080d; }
.hero-purpose { color: #c3d1e2; margin: 1rem 0 1.55rem; }
.address-strip, .address-record { border: 1px solid #49617d; background: linear-gradient(120deg, #172538ed, #0c151fea); box-shadow: inset 0 1px 0 #b7dbff1c; border-radius: 10px; }
.address-strip { display: flex; align-items: center; justify-content: space-between; gap: 2.5rem; padding: .8rem .85rem .8rem 1.05rem; }
.address-strip code, .address-record code { display: block; color: #fff; font-size: 1.1rem; letter-spacing: .035em; }
.address-strip a { color: #071421; background: #c1e1ff; text-decoration: none; font-size: .85rem; font-weight: 750; border-radius: 5px; padding: .58rem .8rem; white-space: nowrap; }
.address-strip a:hover { background: #fff; }
.quiet-link { display: inline-block; margin-top: 1rem; font-size: .94rem; }
.service-rail { display: grid; grid-template-columns: minmax(220px,.8fr) minmax(0,1.6fr); gap: clamp(2rem,6vw,5.4rem); padding-block: 3.2rem 2.6rem; }
.rail-heading p:last-child { max-width: 28ch; }
.service-links { border-top: 1px solid var(--line); }
.service-links a { display: grid; align-items: center; grid-template-columns: auto minmax(0,1fr) auto; gap: 1rem; color: var(--text); padding: 1rem .35rem; text-decoration: none; border-bottom: 1px solid var(--line); }
.service-links a:hover { background: #111b29; }
.step-index { font: 600 .77rem ui-monospace, monospace; color: var(--accent); }
.service-links strong, .service-links small { display: block; }
.service-links small { color: var(--muted); margin-top: .25rem; }
.entry-label { color: var(--accent); font-size: .84rem; }
.guide-index { border-top: 1px solid var(--line); padding-block: 1.6rem 3.2rem; }
.guide-index h2 { font-size: 1.15rem; }
.guide-links { display: flex; gap: .65rem 1.8rem; flex-wrap: wrap; margin-top: .7rem; font-size: .9rem; }
.guide-link h3 { font-size: inherit; font-weight: 540; }
.site-foot { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: flex-start; gap: .4rem 2rem; padding: 1.35rem 0 2rem; border-top: 1px solid var(--line); }
.site-foot p { font-size: .83rem; margin: .3rem 0; }
.inner, .guide-main { max-width: 820px; min-height: 45vh; padding-block: 3.5rem 4rem; }
.inner-lead { max-width: 38rem; margin-bottom: 1.4rem; }
.inner-lead h1 { font-size: clamp(2.05rem, 4.7vw, 3.45rem); letter-spacing: -.036em; }
.inner-lead p { font-size: clamp(1rem,2vw,1.16rem); margin-top: .85rem; }
.inner section, .guide-prose section { margin-top: 1.8rem; }
.inner section > p, .guide-prose p { max-width: 43rem; }
.address-record { padding: 1.05rem 1.3rem; }
.address-record p { margin-bottom: .1rem; }
.decision dl, .guide-prose dl { margin: 1rem 0; border-top: 1px solid var(--line); }
.decision dl div, .guide-prose dl div { display: grid; grid-template-columns: minmax(7rem,1fr) 2fr; gap: 1rem; padding: .85rem .15rem; border-bottom: 1px solid var(--line); }
dt { font-weight: 700; }
dd { margin: 0; color: var(--muted); }
.crumbs { display: flex; flex-wrap: wrap; gap: 1rem; margin-bottom: 1rem; font-size: .88rem; }
.guide-article time { font: .78rem ui-monospace, monospace; color: var(--muted); }
.guide-prose h2 { font-size: 1.26rem; }
.article-next { display: flex; flex-wrap: wrap; align-items: baseline; gap: .5rem 1.25rem; }
.directory-item { border-top: 1px solid var(--line); padding-top: 1rem; }
.directory-item h2 { font-size: 1.3rem; }
@media (min-width: 1000px) {
  .earth-frame { width: min(75vw, 895px); max-height: none; inset: 50% 0 auto auto; transform: translateY(-50%); height: auto; }
}
@media (max-width: 700px) {
  .wrap, .mast-inner, .hero-inner, .site-foot { width: calc(100% - 2rem); }
  .mast-inner { gap: .4rem .8rem; flex-wrap: wrap; min-height: 58px; padding-block: .4rem; }
  .mast nav { gap: .2rem .8rem; }
  .mast nav a { font-size: .78rem; }
  .orbital { min-height: 0; display: flex; flex-direction: column; background: #080c13; }
  .hero-inner { order: 0; padding-block: 1.8rem .3rem; }
  .hero-inner h1 { font-size: clamp(2.15rem,10.5vw,3.75rem); }
  .hero-purpose { margin: .65rem 0 1rem; }
  .address-strip { width: 100%; gap: .65rem; }
  .quiet-link { margin-top: .75rem; }
  .earth-frame { order: 1; position: relative; width: 100%; max-width: 560px; margin: -.2rem auto 0; z-index: -1; }
  .earth-frame::after { background: linear-gradient(180deg,#080c13 0%,transparent 14%),linear-gradient(0deg,#080b10,transparent 14%); }
  .service-rail { display: block; padding-block: 1rem 1.65rem; }
  .rail-heading p:last-child { max-width: none; }
  .service-links a { grid-template-columns: auto minmax(0,1fr); gap: .2rem .7rem; padding-block: .75rem; }
  .entry-label { grid-column: 2; }
  .inner, .guide-main { padding-block: 2rem 2.75rem; }
  .decision dl div, .guide-prose dl div { grid-template-columns: minmax(0,1fr); gap: .3rem; }
}
@media (prefers-reduced-motion: reduce) { .earth-flow { display: none; } }