/* ============================================================
   快连 kuailianklaps.com.cn — 「航线控制台」ROUTE CONSOLE
   设计语言:白昼导航仪表台 · 浅空底 · 仪器面板 · 等宽遥测 · 蓝紫渐变航线图
   ============================================================ */

:root {
  --void:   #070b16;   /* 页面底 — 深空 */
  --panel:  #0d1526;   /* 面板 */
  --panel2: #121b30;   /* 抬升面板 */
  --line:   #1c2945;   /* 发丝线 */
  --line2:  #2a3a60;   /* 强发丝线 */
  --ink:    #eaf1ff;   /* 主文字 */
  --muted:  #9aa7c9;   /* 次级文字 */
  --faint:  #5f6d95;   /* 三级/标签 */
  --volt:   #b6f04b;   /* 主色 — 伏特荧光绿 */
  --volt-d: #9ad33a;
  --volt-ink: #0a1304;
  --volt-12: rgba(182, 240, 75, .12);
  --volt-30: rgba(182, 240, 75, .30);
  --ice:    #7fd4ff;   /* 数据蓝 */
  --amber:  #f5c451;   /* 价格琥珀 */
  --danger: #ff8a80;
  --mono: "SF Mono", ui-monospace, "Cascadia Code", Consolas, "JetBrains Mono", Menlo, monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  --rad: 12px;
  --wrap: 1120px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--ink);
  background-color: var(--void);
  background-image: url(../images/section-grid.svg);
  background-size: 400px 400px;
  -webkit-font-smoothing: antialiased;
}

::selection { background: var(--volt); color: var(--volt-ink); }

a { color: var(--volt); text-decoration: none; }

img { max-width: 100%; display: block; }

.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 24px; }

/* ---------- 通用排版 ---------- */
h1, h2, h3, h4 { line-height: 1.25; letter-spacing: -.015em; font-weight: 800; color: var(--ink); }
h1 { font-size: clamp(30px, 4.4vw, 46px); }
h2 { font-size: clamp(24px, 3vw, 32px); }
h3 { font-size: 19px; }
h4 { font-size: 16px; }

.volt { color: var(--volt); }
.mono { font-family: var(--mono); }

/* 顶部状态条 */
.topbar {
  background: #05080f;
  border-bottom: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 12.5px;
  letter-spacing: .02em;
}
.topbar .wrap { display: flex; align-items: center; gap: 10px; padding-top: 8px; padding-bottom: 8px; flex-wrap: wrap; }
.topbar .tb-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--volt); box-shadow: 0 0 8px var(--volt); flex: none; }
.topbar .tb-txt { color: var(--muted); }
.topbar .tb-link { color: var(--volt); font-weight: 600; margin-left: auto; }
.topbar .tb-link:hover { text-decoration: underline; }

/* ---------- 顶栏 masthead ---------- */
.masthead {
  position: sticky; top: 0; z-index: 60;
  background: rgba(7, 11, 22, .86);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}
.masthead .wrap { display: flex; align-items: center; justify-content: space-between; gap: 24px; padding-top: 14px; padding-bottom: 14px; }

.wordmark { display: inline-flex; align-items: center; gap: 11px; color: var(--ink); }
.wm-mark { width: 34px; height: 34px; border-radius: 8px; border: 1px solid var(--line); flex: none; display: block; }
.mastfoot .wm-mark { width: 28px; height: 28px; border-radius: 7px; }
.wm-text { display: flex; flex-direction: column; line-height: 1.05; }
.wm-name { font-size: 19px; font-weight: 800; letter-spacing: .02em; color: var(--ink); }
.wm-sub { font-family: var(--mono); font-size: 10px; letter-spacing: .16em; color: var(--faint); text-transform: uppercase; }

.nav-wrap { display: flex; align-items: center; gap: 10px; }
.nav { display: flex; gap: 4px; list-style: none; align-items: center; }
.nav a {
  display: block; padding: 8px 14px; border-radius: 8px;
  font-family: var(--mono); font-size: 13.5px; font-weight: 500; color: var(--muted);
  letter-spacing: .02em;
}
.nav a:hover { color: var(--ink); background: var(--panel2); }
.nav a.active { color: var(--volt); background: var(--volt-12); }

.nav-toggle { display: none; background: none; border: 1px solid var(--line); color: var(--ink); font-size: 20px; border-radius: 8px; width: 40px; height: 40px; cursor: pointer; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  font-family: var(--mono); font-size: 14px; font-weight: 600; letter-spacing: .01em;
  padding: 12px 24px; border-radius: 10px; border: 1px solid transparent; cursor: pointer;
  transition: transform .15s ease, box-shadow .15s ease, background .15s ease, border-color .15s ease;
}
.btn-primary { background: linear-gradient(135deg,#4DABF7 0%,#7557F8 55%,#E946A9 100%); color:#fff; }
.btn-primary:hover { background: linear-gradient(135deg,#3b97ef 0%,#6648f0 55%,#d43799 100%); transform: translateY(-1px); box-shadow: 0 8px 24px rgba(117,87,248,.28); }
.btn-outline { background: transparent; color: var(--volt); border-color: var(--line2); }
.btn-outline:hover { border-color: var(--volt); background: var(--volt-12); }
.btn-lg { padding: 15px 32px; font-size: 15px; border-radius: 12px; }
.btn-sm { padding: 9px 18px; font-size: 13px; }
.nav-cta { flex: none; }

/* ---------- 分区 ---------- */
.section { padding: 72px 0; }
.section.alt { background: rgba(13, 21, 38, .45); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.sec-head { max-width: 720px; margin: 0 auto 40px; text-align: center; }
.sec-head h2 { margin-bottom: 10px; }
.sec-head p { color: var(--muted); font-size: 16px; }
.kicker {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--mono); font-size: 12px; letter-spacing: .16em; text-transform: uppercase;
  color: var(--volt); margin-bottom: 14px;
}
.kicker::before { content: "//"; color: var(--faint); }

/* ---------- 首屏 console-hero(虚化航线背景) ---------- */
.console-hero { position: relative; padding: 96px 0 84px; overflow: hidden; }
.ch-bg {
  position: absolute; inset: -40px 0; z-index: 0;
  background: url(../images/earth-network.jpg) center/cover no-repeat;
  filter: blur(24px) saturate(1.5) contrast(1.06) brightness(.94);
  transform: scale(1.16);
  opacity: .7;
}
.ch-bg::after {
  content: ""; position: absolute; inset: 0;
  background:
    radial-gradient(920px 520px at 20% 32%, rgba(182, 240, 75, .20), transparent 62%),
    radial-gradient(780px 480px at 84% 70%, rgba(127, 212, 255, .18), transparent 60%),
    radial-gradient(560px 420px at 60% 12%, rgba(245, 196, 81, .12), transparent 58%),
    linear-gradient(180deg, rgba(7, 11, 22, .70) 0%, rgba(7, 11, 22, .40) 48%, rgba(7, 11, 22, .88) 100%);
}
.console-hero::before {
  content: ""; position: absolute; inset: 0; z-index: 1;
  background: url(../images/hero-lines.svg) center/cover no-repeat;
  opacity: .55;
  mix-blend-mode: screen;
  pointer-events: none;
}
.console-hero .wrap { position: relative; z-index: 2; }
.ch-left { max-width: 660px; }
.ch-stats { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 36px; padding-top: 26px; border-top: 1px solid var(--line2); }
.cs {
  flex: 1 1 150px; min-width: 140px;
  background: rgba(13, 21, 38, .55); border: 1px solid var(--line);
  border-radius: 10px; padding: 14px 18px;
  backdrop-filter: blur(4px); -webkit-backdrop-filter: blur(4px);
}
.cs b { display: block; font-family: var(--mono); font-size: 26px; font-weight: 700; color: var(--ink); line-height: 1.1; }
.cs b small { font-size: 14px; color: var(--volt); margin-left: 3px; font-weight: 600; }
.cs span { display: block; font-family: var(--mono); font-size: 11.5px; letter-spacing: .12em; color: var(--faint); text-transform: uppercase; margin-top: 6px; }

.eyebrow {
  display: inline-flex; align-items: center; gap: 10px;
  font-family: var(--mono); font-size: 12.5px; letter-spacing: .14em; text-transform: uppercase;
  color: var(--volt); margin-bottom: 18px;
}
.eyebrow .ey-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--volt); box-shadow: 0 0 8px var(--volt); }
.console-hero h1 { margin-bottom: 18px; }
.console-hero .lead { color: var(--muted); font-size: 17px; max-width: 540px; margin-bottom: 28px; }
.ch-cta { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 24px; }
.ch-tags { display: flex; gap: 10px; flex-wrap: wrap; }
.chip {
  font-family: var(--mono); font-size: 12.5px; color: var(--muted);
  padding: 6px 12px; border: 1px solid var(--line); border-radius: 999px;
  background: rgba(13, 21, 38, .6);
}
.chip b { color: var(--ink); font-weight: 600; }

/* (遥测仪表已移除 — hero 改用虚化背景 + 底部数据带 .ch-stats) */

/* ---------- 节点航线图 ---------- */
.route-map {
  position: relative; border: 1px solid var(--line); border-radius: var(--rad);
  background:
    linear-gradient(rgba(42, 58, 96, .14) 1px, transparent 1px),
    linear-gradient(90deg, rgba(42, 58, 96, .14) 1px, transparent 1px),
    linear-gradient(180deg, var(--panel2), var(--panel));
  background-size: 44px 44px, 44px 44px, 100% 100%;
  overflow: hidden;
  box-shadow: 0 30px 60px -30px rgba(0,0,0,.12);
}
.route-map svg { display: block; width: 100%; height: auto; }
.rm-route { stroke: var(--volt); stroke-width: 1.4; stroke-dasharray: 5 6; opacity: .38; fill: none; }
.rm-route.ice { stroke: var(--ice); opacity: .3; }
.rm-node { fill: var(--ice); }
.rm-node.volt { fill: var(--volt); }
.rm-city { font-family: var(--mono); font-size: 14px; fill: var(--ink); }
.rm-lat { font-family: var(--mono); font-size: 12px; fill: var(--faint); }
.rm-origin { fill: var(--volt); }
.rm-pulse { fill: none; stroke: var(--volt); stroke-width: 1.5; animation: rmring 2.6s infinite; }
@keyframes rmring {
  0%   { r: 6; opacity: .8; }
  100% { r: 26; opacity: 0; }
}

/* ---------- 协议功能卡 ---------- */
.protocol-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.proto {
  position: relative; background: var(--panel); border: 1px solid var(--line);
  border-radius: var(--rad); padding: 26px 24px; transition: border-color .2s ease, transform .2s ease;
}
.proto:hover { border-color: var(--line2); transform: translateY(-3px); }
.proto::before, .proto::after {
  content: ""; position: absolute; width: 14px; height: 14px; pointer-events: none;
}
.proto::before { top: -1px; left: -1px; border-top: 2px solid var(--volt); border-left: 2px solid var(--volt); border-top-left-radius: var(--rad); }
.proto::after { bottom: -1px; right: -1px; border-bottom: 2px solid var(--volt); border-right: 2px solid var(--volt); border-bottom-right-radius: var(--rad); }
.proto-tag {
  display: inline-block; font-family: var(--mono); font-size: 11px; letter-spacing: .08em;
  color: var(--volt); background: var(--volt-12); padding: 4px 9px; border-radius: 6px; margin-bottom: 14px;
}
.proto-tag.ice { color: var(--ice); background: rgba(127,212,255,.14); }
.proto-tag.amber { color: var(--amber); background: rgba(245,196,81,.14); }
.proto h3 { margin-bottom: 8px; font-size: 17px; }
.proto p { color: var(--muted); font-size: 14.5px; line-height: 1.7; }

/* ---------- 终端日志步骤 ---------- */
.log { max-width: 720px; margin: 0 auto; }
.log-head { display: flex; align-items: center; gap: 8px; font-family: var(--mono); font-size: 12px; color: var(--faint); margin-bottom: 16px; }
.log-head .dots { display: flex; gap: 5px; }
.log-head .dots i { width: 9px; height: 9px; border-radius: 50%; background: var(--line2); }
.log-head .dots i:first-child { background: var(--volt); }
.log-line { display: flex; gap: 20px; padding: 18px 4px; border-bottom: 1px solid var(--line); }
.log-line:last-child { border-bottom: none; }
.log-line .ln { font-family: var(--mono); font-size: 14px; color: var(--volt); font-weight: 700; flex: none; padding-top: 3px; }
.log-line h3 { font-size: 16px; margin-bottom: 5px; }
.log-line p { color: var(--muted); font-size: 14.5px; }

/* 步骤(render_matrix 沿用 .steps/.step,映射为日志样式) */
.steps { max-width: 720px; margin: 0 auto; }
.step { display: flex; gap: 20px; padding: 18px 4px; border-bottom: 1px solid var(--line); }
.step:last-child { border-bottom: none; }
.step .n { font-family: var(--mono); font-size: 14px; color: var(--volt); font-weight: 700; flex: none; padding-top: 3px; }
.step .b h3 { font-size: 16px; margin-bottom: 5px; }
.step .b p { color: var(--muted); font-size: 14.5px; }

/* ---------- 左右图文 ---------- */
.split { display: grid; grid-template-columns: 1fr 1fr; gap: 44px; align-items: center; }
.split.rev .img { order: -1; }
.split h2 { margin-bottom: 16px; }
.split .txt p { color: var(--muted); margin-bottom: 14px; }
.split .txt .btn { margin-top: 8px; }
.split .img img {
  border: 1px solid var(--line); border-radius: var(--rad);
  box-shadow: 0 24px 48px -24px rgba(0,0,0,.18);
}

/* ---------- 表格 ---------- */
.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--rad); background: var(--panel); }
table { width: 100%; border-collapse: collapse; min-width: 560px; }
thead th {
  font-family: var(--mono); font-size: 12px; letter-spacing: .1em; text-transform: uppercase;
  color: var(--volt); background: var(--panel2); text-align: left; padding: 14px 18px;
  border-bottom: 1px solid var(--line2);
}
tbody td { padding: 14px 18px; border-bottom: 1px solid var(--line); color: var(--muted); font-size: 14.5px; }
tbody tr:last-child td { border-bottom: none; }
tbody tr:hover td { background: rgba(127,212,255,.05); }
td.strong { color: var(--ink); font-weight: 600; }
.ver-table th:not(:first-child), .ver-table td:not(:first-child) { text-align: center; }
.ver-table tbody td:first-child { color: var(--ink); font-weight: 600; }
.badge-hit { font-family: var(--mono); font-size: 11px; color: var(--volt); background: var(--volt-12); padding: 2px 7px; border-radius: 5px; margin-left: 6px; }

/* ---------- 提示 / 警示 / 引用 ---------- */
.tip, .callout {
  display: flex; gap: 14px; align-items: flex-start;
  background: var(--panel); border: 1px solid var(--line); border-left: 3px solid var(--volt);
  border-radius: 10px; padding: 18px 20px; font-size: 14.5px; color: var(--muted);
}
.tip .e, .callout .e { flex: none; font-size: 18px; line-height: 1.4; }
.callout { border-left-color: var(--ice); }
blockquote {
  border-left: 3px solid var(--volt); padding: 6px 0 6px 20px; color: var(--ink);
  font-size: 16px; margin: 20px 0;
}

/* ---------- FAQ ---------- */
.faq { max-width: 820px; margin: 0 auto; }
.faq-group-label { display: flex; align-items: center; gap: 10px; font-family: var(--mono); font-size: 13px; letter-spacing: .1em; color: var(--volt); text-transform: uppercase; margin: 34px 0 10px; }
.faq-group-label:first-child { margin-top: 0; }
.faq-group-label::before { content: "//"; color: var(--faint); }
.faq-item { border: 1px solid var(--line); border-radius: 10px; background: var(--panel); margin-bottom: 12px; overflow: hidden; }
.faq-q {
  width: 100%; text-align: left; background: none; border: none; cursor: pointer;
  font-family: var(--mono); font-size: 15px; font-weight: 600; color: var(--ink);
  padding: 18px 20px; display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.faq-q:hover { color: var(--volt); }
.faq-q .x { font-size: 20px; color: var(--faint); font-weight: 400; transition: transform .2s ease; flex: none; }
.faq-item.open .faq-q .x { transform: rotate(45deg); color: var(--volt); }
.faq-a { max-height: 0; overflow: hidden; transition: max-height .3s ease; }
.faq-a p { padding: 0 20px 20px; color: var(--muted); font-size: 14.5px; }
.faq-a a { color: var(--volt); text-decoration: underline; }

/* ---------- 子页 hero ---------- */
.page-hero { padding: 64px 0 40px; border-bottom: 1px solid var(--line); }
.page-hero h1 { margin-bottom: 14px; }
.page-hero > .wrap > p { color: var(--muted); font-size: 16.5px; max-width: 680px; }
.breadcrumb { display: flex; align-items: center; gap: 8px; font-family: var(--mono); font-size: 13px; color: var(--faint); margin-bottom: 20px; }
.breadcrumb a { color: var(--faint); }
.breadcrumb a:hover { color: var(--volt); }
.breadcrumb .sep { color: var(--line2); }

/* ---------- 文章 ---------- */
.article-hero { padding: 56px 0 40px; border-bottom: 1px solid var(--line); }
.article-hero h1 { max-width: 860px; margin-bottom: 18px; font-size: clamp(26px, 3.6vw, 38px); }
.article-hero .meta { display: flex; gap: 20px; flex-wrap: wrap; font-family: var(--mono); font-size: 13px; color: var(--faint); }
.article-hero .meta b { color: var(--muted); font-weight: 600; }
.article-body { display: grid; grid-template-columns: 220px 1fr; gap: 48px; padding: 48px 24px; align-items: start; max-width: var(--wrap); margin: 0 auto; }

.toc { position: sticky; top: 90px; border: 1px solid var(--line); border-radius: 10px; background: var(--panel); padding: 20px; }
.toc h5 { font-family: var(--mono); font-size: 12px; letter-spacing: .14em; text-transform: uppercase; color: var(--volt); margin-bottom: 14px; }
.toc ol { list-style: none; }
.toc li { margin-bottom: 9px; }
.toc li a { display: flex; gap: 10px; font-size: 13.5px; color: var(--muted); line-height: 1.45; }
.toc li a:hover { color: var(--volt); }
.toc .num { font-family: var(--mono); color: var(--faint); flex: none; }

.prose { max-width: 720px; }
.prose h2 { font-size: 24px; margin: 40px 0 14px; padding-top: 20px; border-top: 1px solid var(--line); }
.prose h2:first-child { margin-top: 0; padding-top: 0; border-top: none; }
.prose p { color: #c3cee4; margin-bottom: 18px; font-size: 16px; }
.prose strong { color: var(--ink); }
.prose ul, .prose ol { margin: 0 0 20px 4px; padding-left: 24px; }
.prose li { color: #c3cee4; margin-bottom: 9px; }
.prose a { color: var(--volt); text-decoration: underline; }
.prose figure { margin: 28px 0; }
.prose figure img { border: 1px solid var(--line); border-radius: var(--rad); width: 100%; }
.prose figcaption { font-family: var(--mono); font-size: 12.5px; color: var(--faint); margin-top: 10px; text-align: center; }

.share { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; margin-top: 40px; padding-top: 24px; border-top: 1px solid var(--line); }
.share-lbl { font-family: var(--mono); font-size: 12px; letter-spacing: .12em; text-transform: uppercase; color: var(--faint); margin-right: 4px; }
.share a { font-family: var(--mono); font-size: 13px; color: var(--muted); border: 1px solid var(--line); border-radius: 999px; padding: 7px 15px; }
.share a:hover { color: var(--volt); border-color: var(--volt); }

/* 相关卡片 */
.rel-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.rel-card { display: block; background: var(--panel); border: 1px solid var(--line); border-radius: 10px; padding: 20px; transition: border-color .2s ease, transform .2s ease; }
.rel-card:hover { border-color: var(--line2); transform: translateY(-3px); }
.rel-card .tag { display: inline-block; font-family: var(--mono); font-size: 11px; color: var(--volt); background: var(--volt-12); padding: 3px 8px; border-radius: 5px; margin-bottom: 10px; }
.rel-card h4 { font-size: 15.5px; margin-bottom: 7px; color: var(--ink); }
.rel-card p { font-size: 13.5px; color: var(--muted); line-height: 1.6; }

/* ---------- CTA 带 ---------- */
.cta-band {
  text-align: center; border: 1px solid var(--line2); border-radius: 16px;
  background:
    radial-gradient(700px 300px at 50% -40%, rgba(182,240,75,.16), transparent 70%),
    var(--panel2);
  padding: 56px 32px;
}
.cta-band h2 { margin-bottom: 12px; }
.cta-band p { color: var(--muted); margin-bottom: 26px; }

/* ---------- 搜索 ---------- */
.searchbox input {
  width: 100%; padding: 16px 20px; font-family: var(--mono); font-size: 16px;
  background: var(--panel); color: var(--ink); border: 1px solid var(--line); border-radius: 12px; outline: none;
}
.searchbox input:focus { border-color: var(--volt); box-shadow: 0 0 0 3px var(--volt-12); }
.search-results { list-style: none; }
.search-results li { border-bottom: 1px solid var(--line); padding: 14px 2px; }
.search-results a { color: var(--ink); font-size: 15.5px; }
.search-results a:hover { color: var(--volt); }

/* ---------- 网站地图 ---------- */
.sitemap-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.sitemap-col { background: var(--panel); border: 1px solid var(--line); border-radius: 12px; padding: 24px; }
.sitemap-col h3 { font-family: var(--mono); font-size: 13px; letter-spacing: .1em; text-transform: uppercase; color: var(--volt); margin-bottom: 16px; }
.sitemap-col ul { list-style: none; }
.sitemap-col li { margin-bottom: 9px; }
.sitemap-col a { color: var(--muted); font-size: 14.5px; }
.sitemap-col a:hover { color: var(--volt); }

/* ---------- 页脚 mastfoot ---------- */
.mastfoot { border-top: 1px solid var(--line); background: #05080f; padding: 48px 0 32px; }
.mf-top { display: flex; align-items: center; justify-content: space-between; gap: 24px; flex-wrap: wrap; padding-bottom: 24px; border-bottom: 1px solid var(--line); }
.mf-nav { display: flex; gap: 18px; flex-wrap: wrap; }
.mf-nav a { font-family: var(--mono); font-size: 13.5px; color: var(--muted); }
.mf-nav a:hover { color: var(--volt); }
.mf-links { display: flex; gap: 8px 18px; flex-wrap: wrap; align-items: center; padding: 22px 0; font-family: var(--mono); font-size: 12.5px; }
.mf-links a { color: var(--faint); }
.mf-links a:hover { color: var(--volt); }
.mf-links .mf-g { color: var(--volt); letter-spacing: .08em; margin-right: 4px; }
.mf-bot { display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap; border-top: 1px solid var(--line); padding-top: 22px; font-family: var(--mono); font-size: 12.5px; color: var(--faint); }

/* ---------- 返回顶部 ---------- */
.backtop {
  position: fixed; right: 22px; bottom: 22px; width: 44px; height: 44px; border-radius: 10px;
  background: var(--volt); color: var(--volt-ink); border: none; cursor: pointer;
  font-size: 20px; font-weight: 700; opacity: 0; pointer-events: none; transform: translateY(8px);
  transition: opacity .25s ease, transform .25s ease; z-index: 70;
  box-shadow: 0 10px 24px rgba(182,240,75,.3);
}
.backtop.show { opacity: 1; pointer-events: auto; transform: translateY(0); }

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  .protocol-grid { grid-template-columns: 1fr 1fr; }
  .article-body { grid-template-columns: 1fr; }
  .toc { position: static; }
  .sitemap-grid { grid-template-columns: 1fr 1fr; }
  .rel-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 680px) {
  .nav { display: none; position: absolute; top: 100%; left: 0; right: 0; flex-direction: column; background: var(--panel); border-bottom: 1px solid var(--line); padding: 12px 24px; gap: 2px; }
  .nav.open { display: flex; }
  .nav-toggle { display: block; }
  .nav-cta { margin-left: auto; }
  .masthead .wrap { flex-wrap: wrap; }
  .protocol-grid { grid-template-columns: 1fr; }
  .split { grid-template-columns: 1fr; }
  .split.rev .img { order: 0; }
  .sitemap-grid { grid-template-columns: 1fr; }
  .rel-grid { grid-template-columns: 1fr; }
  .ch-cta .btn { flex: 1 1 auto; }
  .mf-top { flex-direction: column; align-items: flex-start; }
}

/* ---------- 下载平台磁贴 ---------- */
.platform-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.platform { display: flex; flex-direction: column; background: var(--panel); border: 1px solid var(--line); border-radius: var(--rad); padding: 26px 24px; transition: border-color .2s ease, transform .2s ease; }
.platform:hover { border-color: var(--volt); transform: translateY(-3px); }
.platform .pf-os { font-size: 30px; line-height: 1; margin-bottom: 14px; }
.platform h3 { font-size: 17px; margin-bottom: 6px; color: var(--ink); }
.platform p { color: var(--muted); font-size: 14px; flex: 1; margin-bottom: 6px; }
.platform .pf-meta { font-family: var(--mono); font-size: 12px; color: var(--faint); margin-bottom: 16px; }
.platform .btn { width: 100%; }
@media (max-width: 900px) { .platform-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 680px) { .platform-grid { grid-template-columns: 1fr; } }