/* =====================================================
   飞利信 Philisense — 北斗遥感与地理信息应用研究院
   v3 「轨道测绘 · 田野考察」编辑式版式
   语言：深浅交替章节 / 信号橙 × 墨蓝 / 等宽遥测字体 /
         巨型轮廓水印 / 轨道 SVG / 粘性管线 / 横向路线
   依赖 styles.css 全局基座（变量 / 白色 sticky 导航 / 页脚）
   ===================================================== */
:root {
  --ink: #0a1b3f;          /* 墨蓝 */
  --ink-2: #10264f;
  --abyss: #050d21;        /* 深色章节底 */
  --paper: #f4f7fd;        /* 浅色章节底 */
  --acc: #ff6a3d;          /* 信号橙 */
  --acc-soft: #ffe9e1;
  --blue: #1f5eff;
  --cyan: #17b6d8;
  --txt: #16233f;          /* 浅底正文 */
  --sub: #5b6b8c;
  --hair: rgba(10, 27, 63, .14);
  --hair-l: rgba(140, 180, 255, .2);
  --lt: #e9f0ff;           /* 深底正文 */
  --mono: "JetBrains Mono", "Cascadia Code", Consolas, "Courier New", monospace;
  --disp: "Space Grotesk", "Microsoft YaHei", "PingFang SC", sans-serif;
}

html { scroll-behavior: smooth; }
body { background: var(--paper); color: var(--txt); overflow-x: hidden; }

/* ---------- 进场显现 ---------- */
.rv { opacity: 0; transform: translateY(26px); transition: opacity .75s cubic-bezier(.19,.7,.22,1), transform .75s cubic-bezier(.19,.7,.22,1); }
.rv.in { opacity: 1; transform: none; }
.rv[data-d="1"] { transition-delay: .08s; } .rv[data-d="2"] { transition-delay: .16s; }
.rv[data-d="3"] { transition-delay: .24s; } .rv[data-d="4"] { transition-delay: .32s; }
.rv[data-d="5"] { transition-delay: .4s; }
@media (prefers-reduced-motion: reduce) {
  .rv { opacity: 1; transform: none; transition: none; }
  *, *::before, *::after { animation-duration: .001s !important; }
}

/* ---------- 章节骨架 ---------- */
.st-sec { position: relative; padding: 104px 24px; }
.st-wrap { max-width: 1240px; margin: 0 auto; position: relative; }
.st-dark { background: var(--abyss); color: var(--lt); }
.st-eyebrow {
  display: inline-flex; align-items: center; gap: 12px;
  font-family: var(--mono); font-size: 12px; letter-spacing: .3em;
  text-transform: uppercase; color: var(--acc); margin-bottom: 18px;
}
.st-eyebrow::before { content: ""; width: 34px; height: 2px; background: var(--acc); }
.st-h2 {
  font-family: var(--disp); font-weight: 700;
  font-size: clamp(28px, 3.4vw, 44px); line-height: 1.22; letter-spacing: .5px;
}
.st-lead { margin-top: 16px; font-size: 15px; line-height: 1.9; color: var(--sub); max-width: 620px; }
.st-dark .st-lead { color: rgba(190, 205, 235, .78); }
.st-lead b, .st-lead strong { color: var(--blue); font-weight: 600; }
.st-dark .st-lead b, .st-dark .st-lead strong { color: var(--acc); }

/* 巨型轮廓水印字 */
.st-ghost {
  position: absolute; top: 34px; right: 0; z-index: 0;
  font-family: var(--disp); font-weight: 700; line-height: 1;
  font-size: clamp(72px, 13vw, 168px); letter-spacing: .02em;
  color: transparent; -webkit-text-stroke: 1px rgba(10,27,63,.1);
  user-select: none; pointer-events: none; white-space: nowrap;
}
.st-dark .st-ghost { -webkit-text-stroke: 1px rgba(120,170,255,.14); }

/* =====================================================
   ① HERO —— 深空轨道观测台
   ===================================================== */
.st-hero {
  position: relative; overflow: hidden; color: #fff;
  background:
    radial-gradient(1100px 560px at 78% -10%, rgba(31,94,255,.34), transparent 62%),
    radial-gradient(760px 460px at -6% 96%, rgba(23,182,216,.16), transparent 60%),
    linear-gradient(176deg, #0b1f4d 0%, #071228 58%, var(--abyss) 100%);
}
/* 经纬网格底纹 */
.st-hero::before {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background-image:
    linear-gradient(rgba(140,180,255,.055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(140,180,255,.055) 1px, transparent 1px);
  background-size: 52px 52px;
  -webkit-mask-image: radial-gradient(120% 90% at 62% 30%, #000 20%, transparent 82%);
  mask-image: radial-gradient(120% 90% at 62% 30%, #000 20%, transparent 82%);
}
/* 等高线装饰（右上） */
.st-contours { position: absolute; top: -90px; right: -140px; width: 620px; opacity: .5; pointer-events: none; }
/* 星野 */
.st-stars { position: absolute; inset: 0; pointer-events: none; }
.st-stars i {
  position: absolute; width: 2px; height: 2px; border-radius: 50%;
  background: #bcd4ff; animation: stTwk 4.2s ease-in-out infinite;
}
@keyframes stTwk { 0%,100% { opacity:.12; } 50% { opacity:.9; } }

.st-hero-inner {
  position: relative; z-index: 2; max-width: 1240px; margin: 0 auto;
  padding: 74px 24px 0;
  display: grid; grid-template-columns: 1.04fr .96fr; gap: 44px; align-items: center;
  min-height: calc(100vh - 72px);
}
.st-hero-copy .st-eyebrow { color: #8fe3ff; }
.st-hero-copy .st-eyebrow::before { background: #8fe3ff; }
.st-hero-title {
  font-family: var(--disp); font-weight: 700;
  font-size: clamp(40px, 5.6vw, 76px); line-height: 1.12; letter-spacing: 1px;
}
.st-hero-title .o {
  color: transparent; -webkit-text-stroke: 1.6px var(--acc);
}
.st-hero-title em {
  font-style: normal; color: var(--acc);
  text-decoration: underline; text-decoration-thickness: 5px; text-underline-offset: 9px;
  text-decoration-color: rgba(255,106,61,.55);
}
.st-hero-desc { margin-top: 26px; max-width: 520px; font-size: 16px; line-height: 2; color: rgba(205,220,248,.85); }
.st-hero-desc b { color: #fff; font-weight: 600; }
.st-hero-cta { margin-top: 36px; display: flex; gap: 16px; flex-wrap: wrap; }
.st-btn {
  display: inline-flex; align-items: center; gap: 10px;
  font-family: var(--mono); font-size: 13px; letter-spacing: .18em;
  padding: 15px 28px; border-radius: 3px; transition: all .3s ease; cursor: pointer;
}
.st-btn--acc { background: var(--acc); color: #1a0d06; font-weight: 700; box-shadow: 0 12px 32px rgba(255,106,61,.32); }
.st-btn--acc:hover { transform: translateY(-3px); box-shadow: 0 18px 40px rgba(255,106,61,.45); }
.st-btn--line { border: 1px solid rgba(160,200,255,.4); color: #cfe2ff; }
.st-btn--line:hover { border-color: var(--acc); color: var(--acc); transform: translateY(-3px); }

/* 轨道观测台 SVG 面板 */
.st-orbit-panel { position: relative; padding: 12px 0 8px; }
.st-orbit-panel::before, .st-orbit-panel::after,
.st-orbit-corner::before, .st-orbit-corner::after {
  content: ""; position: absolute; width: 26px; height: 26px; pointer-events: none;
  border: 2px solid rgba(143,227,255,.6);
}
.st-orbit-panel::before { top: 0; left: 0; border-right: 0; border-bottom: 0; }
.st-orbit-panel::after { top: 0; right: 0; border-left: 0; border-bottom: 0; }
.st-orbit-corner::before { bottom: 0; left: 0; border-right: 0; border-top: 0; }
.st-orbit-corner::after { bottom: 0; right: 0; border-left: 0; border-top: 0; }
.st-orbit-svg { width: 100%; height: auto; display: block; }
/* 卫星沿椭圆轨道运动 */
.st-sat { offset-path: path("M60,300 a240,104 0 1,1 480,0 a240,104 0 1,1 -480,0"); animation: stOrbit 16s linear infinite; }
.st-sat--2 { animation-duration: 26s; animation-delay: -13s; }
@keyframes stOrbit { to { offset-distance: 100%; } }
.st-scanline { animation: stScan 6s ease-in-out infinite alternate; }
@keyframes stScan { from { transform: translateY(-70px); opacity:.15; } 50% { opacity:.6; } to { transform: translateY(70px); opacity:.15; } }
.st-pulse { transform-origin: center; transform-box: fill-box; animation: stPulse 2.8s ease-out infinite; }
@keyframes stPulse { 0% { transform: scale(.4); opacity:.9; } 100% { transform: scale(2.6); opacity:0; } }
.st-dash-flow { stroke-dasharray: 5 7; animation: stDash 1.2s linear infinite; }
@keyframes stDash { to { stroke-dashoffset: -12; } }

/* HERO 底部遥测数据轨 */
.st-rail {
  position: relative; z-index: 3; border-top: 1px solid rgba(140,180,255,.2);
  background: rgba(5,13,33,.6); backdrop-filter: blur(8px);
}
.st-rail-inner {
  max-width: 1240px; margin: 0 auto; padding: 0 24px;
  display: grid; grid-template-columns: repeat(4, 1fr);
}
.st-rail-cell {
  padding: 22px 18px 20px; border-left: 1px solid rgba(140,180,255,.14);
  transition: background .3s ease;
}
.st-rail-cell:first-child { border-left: 0; }
.st-rail-cell:hover { background: rgba(31,94,255,.14); }
.st-rail-cell .k { font-family: var(--mono); font-size: 10.5px; letter-spacing: .24em; color: rgba(150,180,225,.75); }
.st-rail-cell .v {
  font-family: var(--disp); font-weight: 700; font-size: clamp(26px, 2.6vw, 36px);
  color: #fff; margin-top: 8px; line-height: 1;
}
.st-rail-cell .v small { font-size: 13px; font-weight: 500; color: #8fe3ff; margin-left: 4px; letter-spacing: .1em; }
.st-rail-cell .v .acc { color: var(--acc); }

/* =====================================================
   章节索引条（sticky，紧贴导航之下）
   ===================================================== */
.st-indexbar {
  position: sticky; top: 72px; z-index: 900;
  background: rgba(5,13,33,.92); backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(140,180,255,.16);
}
.st-indexbar-in {
  max-width: 1240px; margin: 0 auto; padding: 0 24px;
  display: flex; align-items: center; gap: 4px; overflow-x: auto; scrollbar-width: none;
}
.st-indexbar-in::-webkit-scrollbar { display: none; }
.st-indexbar a {
  flex: none; display: inline-flex; align-items: baseline; gap: 8px;
  font-family: var(--mono); font-size: 11px; letter-spacing: .16em;
  color: rgba(170,195,235,.72); padding: 15px 16px;
  border-bottom: 2px solid transparent; transition: all .25s ease; white-space: nowrap;
}
.st-indexbar a b { font-weight: 700; color: rgba(255,106,61,.85); }
.st-indexbar a:hover { color: #fff; }
.st-indexbar a.on { color: #fff; border-bottom-color: var(--acc); }

/* =====================================================
   5W 跑马灯条带
   ===================================================== */
.st-marquee { background: var(--ink); border-block: 1px solid rgba(255,255,255,.06); overflow: hidden; }
.st-marquee-track {
  display: flex; width: max-content; padding: 16px 0;
  animation: stMq 30s linear infinite;
}
.st-marquee:hover .st-marquee-track { animation-play-state: paused; }
@keyframes stMq { to { transform: translateX(-50%); } }
.st-mq-item { display: inline-flex; align-items: baseline; gap: 14px; padding: 0 30px; white-space: nowrap; }
.st-mq-item .q { font-family: var(--mono); font-size: 11px; letter-spacing: .22em; color: var(--acc); }
.st-mq-item .w { font-family: var(--disp); font-weight: 700; font-size: 19px; color: #fff; letter-spacing: .06em; }
.st-mq-item .z { font-size: 13px; color: rgba(190,205,235,.7); }
.st-mq-item .dot { width: 6px; height: 6px; background: var(--acc); transform: rotate(45deg); align-self: center; }

/* =====================================================
   ② 学科诞生（浅色 · 左右双栏 + 档案卡）
   ===================================================== */
#origin { background: var(--paper); }
.st-origin-grid { display: grid; grid-template-columns: 1.15fr .85fr; gap: 56px; align-items: start; margin-top: 14px; }
.st-def-quote {
  position: relative; margin-top: 34px; padding: 30px 34px 30px 40px;
  background: #fff; border: 1px solid var(--hair); border-left: 4px solid var(--acc);
  box-shadow: 0 16px 44px rgba(10,27,63,.07); font-size: 16.5px; line-height: 2; color: var(--txt);
}
.st-def-quote::before {
  content: "“"; position: absolute; top: -24px; left: 22px;
  font-family: var(--disp); font-size: 64px; color: var(--acc); opacity: .85;
}
.st-def-quote b { color: var(--blue); }
.st-5w-chips { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 30px; }
.st-5w-chips span {
  display: inline-flex; align-items: baseline; gap: 8px;
  padding: 10px 18px; background: #fff; border: 1px solid var(--hair);
  font-size: 13px; color: var(--sub); transition: all .3s ease; cursor: default;
}
.st-5w-chips span b { font-family: var(--mono); font-size: 11px; letter-spacing: .14em; color: var(--acc); }
.st-5w-chips span:hover { transform: translateY(-3px); border-color: var(--acc); box-shadow: 0 10px 24px rgba(255,106,61,.16); }
/* 档案卡 */
.st-file {
  position: sticky; top: 120px; background: var(--ink); color: var(--lt);
  padding: 0 0 34px; transform: rotate(-1.2deg);
  box-shadow: 0 30px 70px rgba(10,27,63,.3);
}
.st-file-bar {
  display: flex; justify-content: space-between; align-items: center;
  padding: 14px 24px; background: var(--acc); color: #1a0d06;
  font-family: var(--mono); font-size: 11px; font-weight: 700; letter-spacing: .24em;
}
.st-file-body { padding: 30px 28px 0; }
.st-file-stamp {
  float: right; width: 88px; height: 88px; margin: -6px -4px 6px 14px;
  border: 2.5px solid var(--acc); border-radius: 50%; color: var(--acc);
  display: grid; place-items: center; text-align: center;
  font-family: var(--mono); font-size: 10px; line-height: 1.5; letter-spacing: .14em;
  transform: rotate(8deg); opacity: .9;
}
.st-file h3 { font-family: var(--disp); font-size: 21px; color: #fff; margin-bottom: 16px; }
.st-file p { font-size: 13.5px; line-height: 2; color: rgba(200,214,240,.82); }
.st-file-meta { margin-top: 22px; border-top: 1px dashed rgba(140,180,255,.3); }
.st-file-meta div {
  display: flex; justify-content: space-between; gap: 16px; padding: 11px 0;
  border-bottom: 1px dashed rgba(140,180,255,.18); font-size: 12.5px;
}
.st-file-meta span { font-family: var(--mono); letter-spacing: .16em; color: rgba(143,227,255,.6); font-size: 10.5px; padding-top: 2px; }
.st-file-meta i { font-style: normal; color: #fff; text-align: right; }

/* =====================================================
   ③ 研究管线（浅色灰底 · 粘性左栏 + 纵向流程）
   ===================================================== */
#pipeline { background: #eceff7; border-block: 1px solid var(--hair); }
.st-pipe-grid { display: grid; grid-template-columns: .8fr 1.2fr; gap: 64px; align-items: start; }
.st-pipe-left { position: sticky; top: 140px; }
.st-pipe-note {
  margin-top: 30px; padding: 22px 24px; background: #fff;
  border: 1px dashed rgba(10,27,63,.24); font-size: 13px; line-height: 1.9; color: var(--sub);
}
.st-pipe-note b { color: var(--acc); font-family: var(--mono); letter-spacing: .1em; }
.st-steps { position: relative; padding-left: 34px; }
.st-steps::before {
  content: ""; position: absolute; left: 9px; top: 14px; bottom: 14px; width: 2px;
  background: linear-gradient(180deg, var(--acc), var(--blue) 55%, var(--cyan));
}
.st-step { position: relative; padding: 0 0 30px; }
.st-step:last-child { padding-bottom: 0; }
.st-step-dot {
  position: absolute; left: -34px; top: 4px; width: 20px; height: 20px;
  border-radius: 50%; background: #fff; border: 3px solid var(--acc);
  display: grid; place-items: center;
}
.st-step:nth-child(2) .st-step-dot { border-color: var(--blue); }
.st-step:nth-child(3) .st-step-dot { border-color: var(--cyan); }
.st-step:nth-child(4) .st-step-dot { border-color: var(--ink); }
.st-step-dot::after { content: ""; width: 6px; height: 6px; border-radius: 50%; background: currentColor; color: var(--acc); }
.st-step:nth-child(2) .st-step-dot::after { color: var(--blue); }
.st-step:nth-child(3) .st-step-dot::after { color: var(--cyan); }
.st-step:nth-child(4) .st-step-dot::after { color: var(--ink); }
.st-step-card {
  background: #fff; border: 1px solid var(--hair); padding: 26px 28px;
  box-shadow: 0 8px 26px rgba(10,27,63,.05);
  transition: transform .35s ease, box-shadow .35s ease, border-color .35s ease;
}
.st-step-card:hover { transform: translateX(10px); box-shadow: 0 18px 44px rgba(10,27,63,.1); border-color: rgba(255,106,61,.5); }
.st-step-top { display: flex; align-items: baseline; gap: 14px; flex-wrap: wrap; }
.st-step-top .no { font-family: var(--disp); font-weight: 700; font-size: 15px; color: var(--acc); letter-spacing: .1em; }
.st-step-card h3 { font-family: var(--disp); font-size: 20px; color: var(--ink); }
.st-step-top .en { font-family: var(--mono); font-size: 10.5px; letter-spacing: .2em; color: var(--sub); margin-left: auto; }
.st-step-card p { margin-top: 12px; font-size: 14px; line-height: 1.95; color: var(--sub); }
.st-step-tags { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 16px; }
.st-step-tags b {
  font-weight: 500; font-family: var(--mono); font-size: 11px; letter-spacing: .1em;
  padding: 5px 12px; background: var(--paper); border: 1px solid var(--hair); color: var(--ink);
}

/* =====================================================
   ④ 六大技术系统（深色 · 发丝线网格）
   ===================================================== */
#systems { background: var(--abyss); }
#systems::before {
  content: ""; position: absolute; inset: 0; pointer-events: none; opacity: .5;
  background: radial-gradient(900px 420px at 12% 0%, rgba(31,94,255,.18), transparent 65%);
}
.st-sys-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px;
  background: rgba(140,180,255,.16); border: 1px solid rgba(140,180,255,.16);
  margin-top: 8px;
}
.st-sys-cell {
  position: relative; background: rgba(7,18,40,.9); padding: 34px 30px 32px;
  transition: background .35s ease; overflow: hidden;
}
.st-sys-cell::after {
  content: ""; position: absolute; left: 0; bottom: 0; height: 3px; width: 0;
  background: var(--acc); transition: width .45s cubic-bezier(.2,.7,.2,1);
}
.st-sys-cell:hover { background: rgba(16,38,79,.95); }
.st-sys-cell:hover::after { width: 100%; }
.st-sys-no {
  font-family: var(--disp); font-weight: 700; font-size: 46px; line-height: 1;
  color: transparent; -webkit-text-stroke: 1.2px rgba(143,227,255,.4);
  transition: all .35s ease;
}
.st-sys-cell:hover .st-sys-no { -webkit-text-stroke-color: var(--acc); }
.st-sys-cell h3 { font-family: var(--disp); font-size: 19px; color: #fff; margin: 18px 0 12px; }
.st-sys-cell p { font-size: 13px; line-height: 1.95; color: rgba(185,202,232,.72); }
.st-sys-kw { display: flex; flex-wrap: wrap; gap: 7px; margin-top: 18px; }
.st-sys-kw i {
  font-style: normal; font-family: var(--mono); font-size: 10px; letter-spacing: .12em;
  padding: 4px 10px; border: 1px solid rgba(143,227,255,.28); color: #8fe3ff;
}

/* =====================================================
   ⑤ 应用田野（浅色 · Bento 网格）
   ===================================================== */
#fields { background: var(--paper); }
.st-bento {
  display: grid; grid-template-columns: repeat(12, 1fr); gap: 20px; margin-top: 8px;
}
.st-bcell {
  background: #fff; border: 1px solid var(--hair); padding: 34px 32px;
  position: relative; overflow: hidden;
  transition: transform .35s ease, box-shadow .35s ease;
}
.st-bcell:hover { transform: translateY(-6px); box-shadow: 0 24px 54px rgba(10,27,63,.1); }
.st-bcell .tag {
  font-family: var(--mono); font-size: 10.5px; letter-spacing: .24em;
  color: var(--acc); text-transform: uppercase;
}
.st-bcell h3 { font-family: var(--disp); font-size: 24px; color: var(--ink); margin: 12px 0 14px; }
.st-bcell > p { font-size: 14px; line-height: 1.9; color: var(--sub); }
.st-bcell ul { margin-top: 16px; display: grid; gap: 10px; }
.st-bcell li { position: relative; padding-left: 20px; font-size: 13.5px; line-height: 1.8; color: var(--txt); }
.st-bcell li::before {
  content: ""; position: absolute; left: 0; top: 9px; width: 8px; height: 2px; background: var(--acc);
}
/* 低空经济大格 */
.st-b-air { grid-column: span 7; grid-row: span 2; background: var(--ink); color: var(--lt); border: 0; }
.st-b-air h3 { color: #fff; font-size: 28px; }
.st-b-air > p { color: rgba(200,214,240,.8); }
.st-b-air li { color: rgba(214,226,248,.88); }
.st-b-air li::before { background: #8fe3ff; }
.st-b-air .big4d {
  position: absolute; right: 22px; top: 14px; font-family: var(--disp); font-weight: 700;
  font-size: 96px; line-height: 1; color: transparent; -webkit-text-stroke: 1.4px rgba(255,106,61,.65);
}
.st-b-air .airviz { width: min(340px, 100%); margin-top: 26px; }
/* 城市格 */
.st-b-city { grid-column: span 5; }
/* 公卫格 */
.st-b-health { grid-column: span 5; background: #eaf3ff; border-color: rgba(31,94,255,.2); }
.st-b-health .tag { color: var(--blue); }
.st-b-health li::before { background: var(--blue); }
/* 引言格（整行横幅） */
.st-b-quote {
  grid-column: span 12; display: flex; align-items: center; gap: 26px;
  background: #fff8f4; border-color: rgba(255,106,61,.3);
}
.st-b-quote .mark { font-family: var(--disp); font-size: 88px; line-height: .5; color: var(--acc); flex: none; padding-top: 26px; }
.st-b-quote blockquote { font-size: 19px; line-height: 1.9; color: var(--ink); font-weight: 500; }
.st-b-quote cite { margin-top: 10px; display: block; font-style: normal; font-family: var(--mono); font-size: 11px; letter-spacing: .2em; color: var(--sub); }
@media (max-width: 720px) {
  .st-b-quote { flex-direction: column; align-items: flex-start; gap: 8px; }
  .st-b-quote .mark { padding-top: 18px; }
}

/* =====================================================
   ⑥ 转型路线（浅灰 · 横向滑动轨道）
   ===================================================== */
#route { background: #eceff7; border-block: 1px solid var(--hair); }
.st-route-hint {
  display: inline-flex; align-items: center; gap: 10px; margin-top: 22px;
  font-family: var(--mono); font-size: 11px; letter-spacing: .24em; color: var(--acc);
}
.st-route-hint::after { content: "⟶"; font-size: 16px; animation: stNudge 1.4s ease-in-out infinite; }
@keyframes stNudge { 0%,100% { transform: translateX(0); } 50% { transform: translateX(8px); } }
.st-track {
  margin-top: 34px; display: flex; gap: 22px; overflow-x: auto;
  padding: 12px 4px 26px; scroll-snap-type: x mandatory; cursor: grab;
  scrollbar-width: thin; scrollbar-color: var(--acc) transparent;
}
.st-track.dragging { cursor: grabbing; scroll-snap-type: none; }
.st-track::-webkit-scrollbar { height: 5px; }
.st-track::-webkit-scrollbar-thumb { background: var(--acc); border-radius: 3px; }
.st-track::-webkit-scrollbar-track { background: rgba(10,27,63,.08); }
.st-phase {
  flex: none; width: min(360px, 82vw); scroll-snap-align: start;
  background: #fff; border: 1px solid var(--hair); border-top: 4px solid var(--acc);
  padding: 30px 28px 28px; position: relative;
  transition: transform .35s ease, box-shadow .35s ease;
}
.st-phase:nth-child(even) { border-top-color: var(--blue); }
.st-phase:hover { transform: translateY(-8px); box-shadow: 0 24px 50px rgba(10,27,63,.12); }
.st-phase .ph {
  font-family: var(--disp); font-weight: 700; font-size: 44px; line-height: 1;
  color: transparent; -webkit-text-stroke: 1.3px rgba(10,27,63,.3);
}
.st-phase:hover .ph { -webkit-text-stroke-color: var(--acc); }
.st-phase .cat { display: block; margin: 16px 0 8px; font-family: var(--mono); font-size: 10.5px; letter-spacing: .24em; color: var(--acc); }
.st-phase:nth-child(even) .cat { color: var(--blue); }
.st-phase h3 { font-family: var(--disp); font-size: 21px; color: var(--ink); margin-bottom: 12px; }
.st-phase p { font-size: 13.5px; line-height: 1.95; color: var(--sub); }
.st-phase p b { color: var(--ink); }
.st-phase-end {
  flex: none; width: min(300px, 74vw); scroll-snap-align: start;
  display: flex; flex-direction: column; justify-content: center; align-items: flex-start;
  background: var(--ink); color: #fff; padding: 30px 28px;
}
.st-phase-end .end-k { font-family: var(--mono); font-size: 10.5px; letter-spacing: .26em; color: #8fe3ff; }
.st-phase-end h3 { font-family: var(--disp); font-size: 24px; margin: 14px 0 10px; }
.st-phase-end p { font-size: 13px; line-height: 1.9; color: rgba(200,214,240,.78); }

/* =====================================================
   ⑦ 研究院铭牌（深色收束）
   ===================================================== */
#lab { background: var(--abyss); overflow: hidden; }
#lab::before {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background:
    radial-gradient(800px 400px at 88% 20%, rgba(255,106,61,.1), transparent 60%),
    radial-gradient(700px 380px at 8% 90%, rgba(31,94,255,.2), transparent 60%);
}
.st-lab-grid { display: grid; grid-template-columns: 1.2fr .8fr; gap: 56px; align-items: center; }
.st-lab-dirs { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 32px; }
.st-lab-dirs b {
  font-weight: 500; font-size: 13.5px; padding: 10px 20px;
  border: 1px solid rgba(143,227,255,.3); color: #cfe2ff;
  transition: all .3s ease; cursor: default;
}
.st-lab-dirs b:hover { border-color: var(--acc); color: var(--acc); transform: translateY(-3px); }
.st-namecard {
  position: relative; background: rgba(10,26,55,.85); border: 1px solid rgba(143,227,255,.22);
  padding: 38px 34px 34px; backdrop-filter: blur(6px);
}
.st-namecard::before { content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 4px; background: linear-gradient(180deg, var(--acc), var(--blue)); }
.st-namecard .cross {
  position: absolute; top: 22px; right: 24px; width: 44px; height: 44px;
  border: 1.5px solid rgba(255,106,61,.7); border-radius: 50%;
  display: grid; place-items: center; animation: stSpin 14s linear infinite;
}
@keyframes stSpin { to { transform: rotate(360deg); } }
.st-namecard h3 { font-family: var(--disp); font-size: 30px; color: #fff; letter-spacing: .3em; }
.st-namecard .role { margin: 10px 0 18px; font-family: var(--mono); font-size: 11px; letter-spacing: .26em; color: var(--acc); }
.st-namecard p { font-size: 13.5px; line-height: 2; color: rgba(195,210,238,.78); border-top: 1px dashed rgba(143,227,255,.24); padding-top: 18px; }

/* =====================================================
   响应式
   ===================================================== */
@media (max-width: 1080px) {
  .st-hero-inner { grid-template-columns: 1fr; padding-top: 56px; min-height: 0; }
  .st-orbit-panel { max-width: 560px; margin: 10px auto 40px; }
  .st-rail-inner { grid-template-columns: repeat(2, 1fr); }
  .st-rail-cell:nth-child(odd) { border-left: 0; }
  .st-rail-cell:nth-child(n+3) { border-top: 1px solid rgba(140,180,255,.14); }
  .st-origin-grid { grid-template-columns: 1fr; }
  .st-file { position: static; transform: none; max-width: 560px; }
  .st-pipe-grid { grid-template-columns: 1fr; gap: 40px; }
  .st-pipe-left { position: static; }
  .st-sys-grid { grid-template-columns: repeat(2, 1fr); }
  .st-b-air, .st-b-city, .st-b-health, .st-b-quote { grid-column: span 12; grid-row: auto; }
  .st-lab-grid { grid-template-columns: 1fr; }
}
@media (max-width: 720px) {
  .st-sec { padding: 72px 20px; }
  .st-sys-grid { grid-template-columns: 1fr; }
  .st-hero-title { font-size: 38px; }
  .st-contours { display: none; }
  .st-ghost { font-size: 64px; top: 20px; }
  .st-b-air .big4d { font-size: 64px; }
}