/* ==========================================================================
   J9九游会 · 全站共享样式 / assets/site.css
   骨架：侧边导览（品牌轨道 + 双层信息导航）+ 右侧内容带
   ========================================================================== */

/* ---- 1. Reset ---------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body, h1, h2, h3, h4, h5, p, ul, ol, figure, blockquote, dl, dd { margin: 0; }
ul, ol { padding: 0; list-style: none; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
img, svg, video { display: block; max-width: 100%; }
h1, h2, h3, h4 { font-weight: 700; line-height: 1.2; }
hr { border: 0; border-top: 1px solid var(--slate-700); margin: 0; }
[hidden] { display: none !important; }

/* ---- 2. 设计令牌 -------------------------------------------------------- */
:root {
  --ink-950: #060B16;
  --carbon-900: #111726;
  --slate-700: #2A3448;
  --mist-500: #8B9AB3;
  --mist-050: #E9EFF8;
  --cyan-400: #26E3D4;
  --orange-500: #FF7A31;
  --indigo-700: #1B2C50;
  --green-400: #3FD68C;
  --yellow-400: #F5C84A;

  --rail-w: 108px;
  --shell-max: 1400px;
  --shell-pad: 2rem;

  --font-display: "Barlow Semi Condensed", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, "Courier New", monospace;

  --hair: 1px solid var(--slate-700);
  --hair-soft: 1px solid rgba(42, 52, 72, 0.62);
  --shadow-micro: 0 1px 0 rgba(255, 255, 255, 0.04);
  --shadow-panel: 0 1px 0 rgba(255, 255, 255, 0.04), 0 18px 40px rgba(0, 0, 0, 0.38);
  --ease-out: cubic-bezier(0.16, 0.84, 0.44, 1);
  --radius: 4px;
}

/* ---- 3. 基础排版与画布 -------------------------------------------------- */
html { background: var(--ink-950); }

body {
  background:
    radial-gradient(900px 520px at 82% -8%, rgba(27, 44, 80, 0.55) 0%, rgba(6, 11, 22, 0) 62%),
    radial-gradient(680px 420px at 12% 108%, rgba(38, 227, 212, 0.06) 0%, rgba(6, 11, 22, 0) 60%),
    var(--ink-950);
  color: var(--mist-050);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.75;
  letter-spacing: 0.01em;
  padding-left: var(--rail-w);
  min-height: 100vh;
}

:focus-visible {
  outline: 2px solid var(--cyan-400);
  outline-offset: 2px;
  border-radius: 2px;
}

.num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
}

.shell {
  width: 100%;
  max-width: var(--shell-max);
  margin-inline: auto;
  padding-inline: var(--shell-pad);
}

/* ---- 4. 跳至主要内容 ---------------------------------------------------- */
.skip-link {
  position: absolute;
  left: 0.75rem;
  top: -5rem;
  z-index: 200;
  padding: 0.65rem 1.05rem;
  background: var(--cyan-400);
  color: var(--ink-950);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  border-radius: 2px;
  transition: top 0.16s var(--ease-out);
}
.skip-link:focus { top: 0.75rem; }

/* ---- 5. 页头骨架 ------------------------------------------------------- */
.site-header {
  position: relative;
  z-index: 60;
}

/* 5.1 左侧品牌轨道 + 轮次刻度 */
.rail {
  position: fixed;
  left: 0;
  top: 0;
  bottom: 0;
  z-index: 70;
  width: var(--rail-w);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.9rem;
  padding: 1.4rem 0.6rem;
  background: linear-gradient(180deg, #08101F 0%, #060B16 58%, #0A1526 100%);
  border-right: var(--hair);
}

.rail__brand {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.4rem;
  padding: 0.5rem 0.35rem;
  border: var(--hair);
  border-radius: var(--radius);
  background: rgba(38, 227, 212, 0.04);
  transition: border-color 0.18s ease, background 0.18s ease;
}
.rail__brand:hover {
  border-color: rgba(38, 227, 212, 0.55);
  background: rgba(38, 227, 212, 0.09);
}
.rail__brand-cn {
  writing-mode: vertical-rl;
  text-orientation: upright;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.02rem;
  letter-spacing: 0.14em;
  color: var(--mist-050);
}
.rail__brand-en {
  font-family: var(--font-mono);
  font-size: 0.56rem;
  letter-spacing: 0.28em;
  color: var(--cyan-400);
}

.rail__tagline {
  writing-mode: vertical-rl;
  text-orientation: upright;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.26em;
  color: var(--mist-500);
  text-align: center;
}

.rail__scale {
  position: relative;
  flex: 1 1 auto;
  width: 16px;
  min-height: 70px;
  margin: 0.4rem 0;
  background-image: repeating-linear-gradient(
    to bottom,
    rgba(139, 154, 179, 0.42) 0 1px,
    transparent 1px 13px
  );
}
.rail__scale-now {
  position: absolute;
  left: -5px;
  right: -5px;
  bottom: 0;
  height: 3px;
  border-radius: 2px;
  background: var(--cyan-400);
  box-shadow: 0 0 14px rgba(38, 227, 212, 0.55);
}

.rail__round {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.2rem;
}
.rail__round-k {
  font-family: var(--font-mono);
  font-size: 0.54rem;
  letter-spacing: 0.26em;
  color: var(--mist-500);
}
.rail__round-v {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1;
  color: var(--cyan-400);
}
.rail__icp {
  max-width: 82px;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 0.52rem;
  line-height: 1.5;
  letter-spacing: 0.08em;
  color: var(--mist-500);
  opacity: 0.8;
  word-break: break-all;
}

/* 5.2 吸顶双层导航 */
.topbar {
  position: sticky;
  top: 0;
  z-index: 55;
  background: rgba(6, 11, 22, 0.9);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: var(--hair);
}

.strip {
  display: flex;
  align-items: center;
  gap: 1.4rem;
  flex-wrap: wrap;
  padding-block: 0.5rem;
  border-bottom: var(--hair-soft);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  color: var(--mist-500);
}
.strip__lead {
  display: flex;
  align-items: center;
  gap: 0.1rem;
  color: var(--mist-500);
}
.strip__lead b { color: var(--cyan-400); }

.dot {
  display: inline-block;
  width: 6px;
  height: 6px;
  margin-right: 0.55rem;
  border-radius: 50%;
  background: var(--green-400);
  box-shadow: 0 0 0 3px rgba(63, 214, 140, 0.14);
}
.dot--live {
  background: var(--orange-500);
  box-shadow: 0 0 0 3px rgba(255, 122, 49, 0.16);
  animation: dotPulse 2.6s ease-in-out infinite;
}
@keyframes dotPulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.35; }
}

.strip__stats {
  display: flex;
  align-items: center;
  gap: 1.2rem;
}
.strip__stats li { display: inline-flex; align-items: baseline; gap: 0.45rem; }
.strip__k { color: var(--mist-500); opacity: 0.72; }
.strip__v { color: var(--mist-050); letter-spacing: 0.08em; }

.strip__login {
  margin-left: auto;
  padding: 0.4rem 0.9rem;
  border: 1px solid rgba(255, 122, 49, 0.5);
  border-radius: 3px;
  color: var(--orange-500);
  font-weight: 600;
  letter-spacing: 0.1em;
  transition: background 0.18s ease, color 0.18s ease, border-color 0.18s ease;
}
.strip__login:hover {
  background: var(--orange-500);
  border-color: var(--orange-500);
  color: #150800;
}

.mainnav {
  display: flex;
  align-items: center;
  gap: 1rem;
  height: 62px;
}
.mainnav__list {
  display: flex;
  align-items: center;
  gap: 0.15rem;
  flex: 1 1 auto;
}
.mainnav__list a {
  position: relative;
  display: inline-block;
  padding: 0.5rem 0.85rem;
  border-radius: 3px;
  font-size: 0.96rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--mist-050);
  transition: color 0.18s ease, background 0.18s ease;
}
.mainnav__list a::after {
  content: "";
  position: absolute;
  left: 0.85rem;
  right: 0.85rem;
  bottom: 0.28rem;
  height: 2px;
  background: var(--cyan-400);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.18s var(--ease-out);
}
.mainnav__list a:hover { color: var(--cyan-400); }
.mainnav__list a:hover::after { transform: scaleX(1); }
.mainnav__list a[aria-current="page"] { color: var(--cyan-400); }
.mainnav__list a[aria-current="page"]::after {
  transform: scaleX(1);
  box-shadow: 0 0 10px rgba(38, 227, 212, 0.6);
}

.mainnav__find {
  flex: 0 0 auto;
  padding: 0.45rem 0.9rem;
  border: 1px solid rgba(38, 227, 212, 0.35);
  border-radius: 3px;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.16em;
  color: var(--cyan-400);
  transition: background 0.18s ease, border-color 0.18s ease;
}
.mainnav__find:hover {
  background: rgba(38, 227, 212, 0.1);
  border-color: var(--cyan-400);
}

.navtoggle {
  display: none;
  align-items: center;
  gap: 0.55rem;
  padding: 0.5rem 0.8rem;
  border: var(--hair);
  border-radius: 3px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  color: var(--mist-050);
  transition: border-color 0.18s ease, color 0.18s ease;
}
.navtoggle:hover { border-color: var(--cyan-400); color: var(--cyan-400); }
.navtoggle__bars {
  width: 16px;
  height: 10px;
  background-image:
    linear-gradient(var(--cyan-400), var(--cyan-400)),
    linear-gradient(var(--cyan-400), var(--cyan-400)),
    linear-gradient(var(--cyan-400), var(--cyan-400));
  background-repeat: no-repeat;
  background-size: 100% 2px, 100% 2px, 100% 2px;
  background-position: 0 0, 0 50%, 0 100%;
}

/* ---- 6. 通用正文与结构组件 --------------------------------------------- */
.page-head { padding: 3rem 0 2rem; }
.page-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2rem, 4.4vw, 3.4rem);
  line-height: 1.04;
  letter-spacing: -0.02em;
  color: var(--mist-050);
}
.page-lead {
  max-width: 62ch;
  margin-top: 1rem;
  font-size: 1.05rem;
  color: var(--mist-500);
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  padding-top: 1.6rem;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.14em;
  color: var(--mist-500);
}
.breadcrumb li + li::before {
  content: "/";
  margin-right: 0.5rem;
  color: var(--slate-700);
}
.breadcrumb a:hover { color: var(--cyan-400); }
.breadcrumb [aria-current="page"] { color: var(--mist-050); }

.prose { max-width: 68ch; }
.prose p { margin-bottom: 1.1em; color: var(--mist-500); }
.prose strong { color: var(--mist-050); font-weight: 600; }
.prose h2 {
  margin: 2.2em 0 0.7em;
  font-family: var(--font-display);
  font-size: 1.5rem;
  letter-spacing: -0.01em;
  color: var(--mist-050);
}
.prose h3 {
  margin: 1.8em 0 0.5em;
  font-size: 1.12rem;
  color: var(--mist-050);
}
.prose ul, .prose ol { margin: 0 0 1.2em; padding-left: 1.15rem; }
.prose ul li { list-style: none; position: relative; margin-bottom: 0.5em; color: var(--mist-500); }
.prose ul li::before {
  content: "";
  position: absolute;
  left: -1.05rem;
  top: 0.72em;
  width: 6px;
  height: 1px;
  background: var(--cyan-400);
}
.prose ol { list-style: decimal; }
.prose ol li { margin-bottom: 0.5em; color: var(--mist-500); }
.prose a { color: var(--cyan-400); border-bottom: 1px solid rgba(38, 227, 212, 0.35); }
.prose a:hover { border-bottom-color: var(--cyan-400); }

.eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--cyan-400);
}

.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 1.5rem;
  flex-wrap: wrap;
  padding-bottom: 1rem;
  margin-bottom: 2rem;
  border-bottom: var(--hair);
}
.section-head h2 {
  font-family: var(--font-display);
  font-size: clamp(1.4rem, 2.4vw, 2rem);
  letter-spacing: -0.01em;
}

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: 1.5rem;
}

.panel {
  padding: 1.5rem;
  background: var(--carbon-900);
  border: var(--hair);
  border-radius: var(--radius);
  box-shadow: var(--shadow-micro);
}
.panel--flush { padding: 0; }

.stat {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  padding: 1rem 0;
}
.stat__k {
  font-family: var(--font-mono);
  font-size: 0.63rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--mist-500);
}
.stat__v {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 2rem;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--mist-050);
}
.stat__v--cyan { color: var(--cyan-400); }
.stat__v--orange { color: var(--orange-500); }

.status {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.14em;
  color: var(--mist-500);
}
.status::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--mist-500);
}
.status--ok::before { background: var(--green-400); box-shadow: 0 0 8px rgba(63, 214, 140, 0.5); }
.status--live::before { background: var(--orange-500); box-shadow: 0 0 8px rgba(255, 122, 49, 0.5); }
.status--wait::before { background: var(--yellow-400); box-shadow: 0 0 8px rgba(245, 200, 74, 0.45); }

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.72rem 1.25rem;
  border: var(--hair);
  border-radius: 3px;
  background: var(--carbon-900);
  color: var(--mist-050);
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.14em;
  transition: border-color 0.18s ease, color 0.18s ease, background 0.18s ease;
}
.btn:hover { border-color: var(--cyan-400); color: var(--cyan-400); }

.btn--primary {
  background: var(--orange-500);
  border-color: var(--orange-500);
  color: #140700;
  font-weight: 700;
}
.btn--primary:hover {
  background: #FF8C4D;
  border-color: #FF8C4D;
  color: #140700;
}

.btn--ghost {
  background: transparent;
  border-color: rgba(38, 227, 212, 0.42);
  color: var(--cyan-400);
}
.btn--ghost:hover {
  background: rgba(38, 227, 212, 0.1);
  border-color: var(--cyan-400);
}

/* 分段切换 */
.seg {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 0.25rem;
  padding: 0.25rem;
  background: var(--carbon-900);
  border: var(--hair);
  border-radius: var(--radius);
}
.seg__btn {
  padding: 0.45rem 0.95rem;
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  color: var(--mist-500);
  transition: color 0.16s ease, background 0.16s ease;
}
.seg__btn:hover { color: var(--mist-050); }
.seg__btn[aria-selected="true"] {
  background: rgba(38, 227, 212, 0.12);
  color: var(--cyan-400);
  box-shadow: inset 0 0 0 1px rgba(38, 227, 212, 0.35);
}

.tabpanel { padding-top: 1.5rem; outline: none; }

/* 配图容器 */
.figure {
  position: relative;
  overflow: hidden;
  border: var(--hair);
  border-radius: var(--radius);
  background:
    linear-gradient(148deg, var(--indigo-700) 0%, var(--carbon-900) 52%, var(--ink-950) 100%);
}
.figure::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    repeating-linear-gradient(to right, rgba(139, 154, 179, 0.1) 0 1px, transparent 1px 34px),
    repeating-linear-gradient(to bottom, rgba(139, 154, 179, 0.1) 0 1px, transparent 1px 34px);
  pointer-events: none;
}
.figure img,
.figure svg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.figure--wide { aspect-ratio: 16 / 9; }
.figure--tall { aspect-ratio: 4 / 5; }
.figure--band { aspect-ratio: 21 / 9; }
.figure__cap {
  position: absolute;
  left: 1rem;
  right: 1rem;
  bottom: 1rem;
  z-index: 2;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.14em;
  color: var(--mist-050);
  text-shadow: 0 1px 12px rgba(0, 0, 0, 0.85);
}

.glow {
  position: absolute;
  z-index: 0;
  pointer-events: none;
  border-radius: 50%;
  filter: blur(60px);
  opacity: 0.5;
}

/* 显现与阅读进度 */
.js [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.48s var(--ease-out), transform 0.48s var(--ease-out);
}
.js [data-reveal].is-in {
  opacity: 1;
  transform: none;
}

.scrollprogress {
  position: fixed;
  top: 0;
  left: var(--rail-w);
  right: 0;
  height: 2px;
  z-index: 120;
  pointer-events: none;
  background: linear-gradient(90deg, var(--cyan-400) 0%, var(--orange-500) 100%);
  transform: scaleX(0);
  transform-origin: left center;
}

/* ---- 7. 页脚 ----------------------------------------------------------- */
.site-footer {
  margin-top: 6rem;
  background: linear-gradient(180deg, var(--ink-950) 0%, var(--carbon-900) 100%);
  border-top: var(--hair);
}

.footer__inner { padding-block: 3.5rem 2.5rem; }

.footer__head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 2rem;
  flex-wrap: wrap;
  padding-bottom: 1.5rem;
  border-bottom: var(--hair);
}
.footer__logo {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.6rem;
  letter-spacing: -0.01em;
  color: var(--mist-050);
}
.footer__sub {
  margin-top: 0.35rem;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.2em;
  color: var(--mist-500);
}
.footer__motto {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  color: var(--cyan-400);
}

.footer__grid {
  display: grid;
  grid-template-columns: 1fr 1.35fr 1.25fr 1.1fr;
  gap: 2rem;
  padding-top: 2.5rem;
}

.footer__title {
  margin-bottom: 1rem;
  font-family: var(--font-mono);
  font-size: 0.64rem;
  font-weight: 500;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--mist-500);
}

.footer__list li + li { margin-top: 0.55rem; }
.footer__list a {
  font-size: 0.92rem;
  color: var(--mist-050);
  opacity: 0.86;
  transition: color 0.18s ease, opacity 0.18s ease;
}
.footer__list a:hover { color: var(--cyan-400); opacity: 1; }

.footer__list--plain li {
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
}
.footer__k {
  flex: 0 0 auto;
  min-width: 2.4em;
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.16em;
  color: var(--mist-500);
}
.footer__v {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.02em;
  color: var(--mist-050);
  word-break: break-all;
}

.footer__text {
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--mist-500);
}
.footer__text strong { color: var(--mist-050); font-weight: 600; }
.footer__text a {
  color: var(--cyan-400);
  border-bottom: 1px solid rgba(38, 227, 212, 0.35);
}
.footer__text a:hover { border-bottom-color: var(--cyan-400); }
.footer__text--tight { margin-top: 1rem; }

.footer__bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  padding-block: 1.1rem 2rem;
  border-top: var(--hair);
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  color: var(--mist-500);
}
.footer__legal {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
}
.footer__legal a:hover { color: var(--cyan-400); }

/* ---- 8. 响应式 --------------------------------------------------------- */
@media (max-width: 1279px) {
  :root { --rail-w: 0px; }
  body { padding-left: 0; }

  .rail {
    position: static;
    width: 100%;
    height: auto;
    flex-direction: row;
    align-items: center;
    flex-wrap: wrap;
    gap: 1.25rem;
    padding: 0.75rem 1.5rem;
    border-right: 0;
    border-bottom: var(--hair);
  }
  .rail__brand {
    flex-direction: row;
    align-items: baseline;
    gap: 0.55rem;
    padding: 0.3rem 0.7rem;
  }
  .rail__brand-cn {
    writing-mode: horizontal-tb;
    text-orientation: mixed;
    font-size: 1rem;
    letter-spacing: 0.12em;
  }
  .rail__tagline {
    writing-mode: horizontal-tb;
    text-orientation: mixed;
    font-size: 0.7rem;
    letter-spacing: 0.14em;
  }
  .rail__scale { display: none; }
  .rail__round {
    flex-direction: row;
    align-items: baseline;
    gap: 0.4rem;
    margin-left: auto;
  }
  .rail__round-v { font-size: 1.15rem; }
  .rail__icp {
    writing-mode: horizontal-tb;
    max-width: none;
    font-size: 0.58rem;
    letter-spacing: 0.1em;
  }
  .scrollprogress { left: 0; }
}

@media (max-width: 1023px) {
  :root { --shell-pad: 1.5rem; }
  .grid-12 { grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .footer__grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 900px) {
  .mainnav { justify-content: space-between; height: 58px; }
  .navtoggle { display: inline-flex; }

  .mainnav__list {
    position: absolute;
    left: var(--shell-pad);
    right: var(--shell-pad);
    top: calc(100% + 0.5rem);
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 0.5rem;
    background: var(--carbon-900);
    border: var(--hair);
    border-radius: var(--radius);
    box-shadow: var(--shadow-panel);
    z-index: 80;
  }
  [data-nav][data-open] .mainnav__list { display: flex; }

  .mainnav__list a {
    padding: 0.72rem 0.8rem;
    border-bottom: var(--hair-soft);
    border-radius: 0;
  }
  .mainnav__list li:last-child a { border-bottom: 0; }
  .mainnav__list a::after { display: none; }
  .mainnav__list a[aria-current="page"] { background: rgba(38, 227, 212, 0.09); }
}

@media (max-width: 767px) {
  :root { --shell-pad: 1.25rem; }
  body { font-size: 16px; }

  .rail { gap: 0.75rem; padding: 0.6rem 1.25rem; }
  .rail__tagline { display: none; }
  .rail__icp { display: none; }
  .rail__round { margin-left: auto; }

  .strip { gap: 0.9rem; font-size: 0.65rem; }
  .strip__stats { display: none; }

  .page-head { padding: 2.25rem 0 1.5rem; }
  .page-lead { font-size: 1rem; }

  .grid-12 { grid-template-columns: minmax(0, 1fr); }
  .footer__grid { grid-template-columns: minmax(0, 1fr); gap: 1.75rem; }
  .footer__inner { padding-block: 2.5rem 1.75rem; }
  .footer__head { align-items: flex-start; }
  .footer__motto { letter-spacing: 0.1em; }
  .section-head { gap: 0.75rem; }
  .mainnav__list { left: 1rem; right: 1rem; }
}

/* ---- 9. 动效降级 ------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
  html { scroll-behavior: auto; }
  .js [data-reveal] { opacity: 1 !important; transform: none !important; }
  .scrollprogress { display: none !important; }
}