/* ============================================================
   网络科技部 · 厦门双十中学团委学生会 — 门户网站
   tokens 实测自 materials/banner (7ac1...cb0.png)
   ============================================================ */
:root {
  --navy:  #000E83;   /* 横幅实测底色 */
  --deep:  #00065C;   /* 深一档：页脚 / 纳新分区 */
  --royal: #0038D7;   /* 横幅实测亮蓝：交互高亮 */
  --cyan:  #8FD9FF;   /* 终端 / 代码高亮 */
  --ice:   #EEF2FF;   /* 浅色分区纸面 */
  --dim:   #A7B3F0;   /* 深底次要文字 */
  --ink:   #050B4A;   /* 浅底正文 */

  --font-body: 'MiSans', 'HarmonyOS Sans SC', 'PingFang SC', 'Microsoft YaHei UI', 'Microsoft YaHei', system-ui, sans-serif;
  --font-mono: 'Cascadia Code', 'Consolas', 'SF Mono', ui-monospace, monospace;

  --hair: rgba(255, 255, 255, .18);      /* 深底细线 */
  --hair-ice: rgba(5, 11, 74, .18);      /* 浅底细线 */
  --halftone: radial-gradient(circle, rgba(255,255,255,.10) 1.2px, transparent 1.4px);
  --header-h: 68px;
}

/* ---------- reset ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-padding-top: calc(var(--header-h) + 16px); }
@media (prefers-reduced-motion: no-preference) {
  html { scroll-behavior: smooth; }
}
body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  color: var(--ice);
  background: var(--navy);
  -webkit-font-smoothing: antialiased;
}
body.locked { overflow: hidden; }
img { display: block; max-width: 100%; height: auto; }
a { color: var(--cyan); text-decoration: none; }
::selection { background: var(--royal); color: #fff; }

:focus-visible { outline: 2px solid var(--cyan); outline-offset: 3px; }
.sec-ice :focus-visible { outline-color: var(--royal); }

.skip {
  position: absolute; left: 16px; top: -60px; z-index: 200;
  background: var(--cyan); color: var(--deep);
  font-family: var(--font-mono); font-size: 14px;
  padding: 10px 16px; transition: top .2s;
}
.skip:focus { top: 12px; }

/* ---------- 通用 ---------- */
.wrap { max-width: 1180px; margin: 0 auto; padding: 0 24px; }
.sec { padding: 104px 0; position: relative; }
.sec::before {                       /* 半调圆点纹理，来自横幅 */
  content: ""; position: absolute; inset: 0;
  background-image: var(--halftone);
  background-size: 15px 15px;
  opacity: .5; pointer-events: none;
}
.sec > .wrap { position: relative; }
.sec-ice { background: var(--ice); color: var(--ink); }
.sec-ice::before { opacity: .16; }

.eyebrow {
  font-family: var(--font-mono); font-size: 13px;
  letter-spacing: .14em; color: var(--cyan);
  margin-bottom: 14px;
}
.eyebrow-ice { color: var(--royal); }
.h2 {
  font-size: clamp(30px, 4.6vw, 46px);
  font-weight: 900; letter-spacing: .02em;
  line-height: 1.25; margin-bottom: 48px;
}

/* 终端窗口条 */
.win-bar {
  display: flex; align-items: center; gap: 8px;
  font-family: var(--font-mono); font-size: 12px;
  color: var(--dim); letter-spacing: .06em;
  padding: 10px 14px;
  border: 1px solid var(--hair); border-bottom: 0;
  background: rgba(0, 6, 92, .55);
}
.win-bar span { color: var(--royal); font-size: 10px; }
.win-bar em { font-style: normal; margin-left: auto; }
.win-bar-ice {
  border-color: var(--hair-ice);
  background: rgba(5, 11, 74, .05); color: #5A64A8;
}
.win-bar-ice span { color: var(--royal); }

/* 按钮 */
.btn {
  display: inline-block; min-height: 48px;
  font-family: var(--font-mono); font-size: 15px; letter-spacing: .05em;
  padding: 12px 26px; border: 1px solid var(--cyan);
  transition: background .18s, color .18s, border-color .18s;
}
.btn-primary { background: var(--cyan); color: var(--deep); font-weight: 700; }
.btn-primary:hover { background: #fff; border-color: #fff; }
.btn-ghost { background: transparent; color: var(--ice); border-color: var(--hair); }
.btn-ghost:hover { border-color: var(--cyan); color: var(--cyan); }

/* ---------- 开机序列 ---------- */
#boot {
  position: fixed; inset: 0; z-index: 100;
  background: var(--navy);
  display: flex; align-items: center; justify-content: center;
  cursor: pointer;
  transition: opacity .45s;
}
#boot.off { opacity: 0; pointer-events: none; }
.boot-inner {
  width: min(560px, 86vw);
  font-family: var(--font-mono); font-size: 15px; line-height: 2.1;
  color: #BFC9FF;
}
.boot-line { opacity: 0; transform: translateY(4px); }
.boot-line.on { opacity: 1; transform: none; }
.boot-line b { color: #fff; }
.boot-bar {
  width: 100%; height: 14px;
  border: 1px solid var(--hair); margin: 14px 0 6px;
  display: none;
}
.boot-bar.on { display: block; }
.boot-bar i { display: block; height: 100%; width: 0; background: #4D5DF0; }
.boot-skip { font-size: 12px; color: var(--dim); opacity: 0; }
.boot-skip.on { opacity: .8; }

/* ---------- 顶栏 ---------- */
.topbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 50;
  height: var(--header-h);
  display: flex; align-items: center; gap: 24px;
  padding: 0 28px;
  background: rgba(0, 8, 105, .86);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--hair);
}
.brand { display: flex; align-items: center; gap: 12px; }
.brand-logo { width: 38px; height: 38px; object-fit: contain; }
.brand-text { line-height: 1.25; color: var(--ice); }
.brand-text b { display: block; font-size: 16px; font-weight: 800; letter-spacing: .08em; }
.brand-text small { display: block; font-family: var(--font-mono); font-size: 11px; color: var(--dim); letter-spacing: .08em; }
.nav { margin-left: auto; display: flex; align-items: center; gap: 6px; }
.nav-link {
  font-size: 15px; color: var(--dim);
  padding: 10px 13px; min-height: 44px;
  display: inline-flex; align-items: center;
  border-bottom: 2px solid transparent;
}
.nav-link:hover { color: var(--ice); }
.nav-link.is-active { color: var(--ice); border-bottom-color: var(--cyan); }
.nav-cta {
  margin-left: 10px;
  font-family: var(--font-mono); font-size: 14px; font-weight: 700;
  color: var(--deep); background: var(--cyan);
  padding: 9px 18px; min-height: 44px;
  display: inline-flex; align-items: center;
}
.nav-cta:hover { background: #fff; }
.burger {
  display: none; margin-left: auto;
  width: 44px; height: 44px;
  background: none; border: 1px solid var(--hair);
  flex-direction: column; align-items: center; justify-content: center; gap: 5px;
}
.burger span { width: 18px; height: 2px; background: var(--ice);
  transition: transform .45s cubic-bezier(.34,1.56,.64,1), opacity .3s ease; }
.burger[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.burger[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.burger[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- HERO ---------- */
.hero {
  padding: calc(var(--header-h) + 72px) 0 96px;
  background:
    radial-gradient(1100px 480px at 78% -12%, rgba(0, 56, 215, .5), transparent 65%),
    var(--navy);
  position: relative;
}
.hero::before {
  content: ""; position: absolute; inset: 0;
  background-image: var(--halftone); background-size: 15px 15px;
  opacity: .5; pointer-events: none;
}
.hero > * { position: relative; }
.hero-head { max-width: 1180px; margin: 0 auto; padding: 0 24px; text-align: center; }
.hero-title {
  font-size: clamp(58px, 11vw, 132px);
  font-weight: 900; line-height: 1.04;
  letter-spacing: .01em; color: #fff;
  margin: 18px 0 14px;
  text-shadow: 0 0 46px rgba(77, 93, 240, .55);
}
.hero-sub { font-size: clamp(17px, 2.4vw, 22px); color: var(--dim); letter-spacing: .06em; }
.hero-cta { margin-top: 40px; display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.hero-stats {
  margin: 64px auto 0;
  display: grid; grid-template-columns: repeat(4, 1fr);
  max-width: 860px;
  border-top: 1px solid var(--hair);
}
.hero-stats > div {
  padding: 22px 8px 0;
  border-left: 1px solid var(--hair);
}
.hero-stats > div:first-child { border-left: 0; }
.hero-stats dt { font-family: var(--font-mono); font-size: clamp(26px, 3.4vw, 38px); font-weight: 700; color: #fff; }
.hero-stats dd { font-size: 13px; color: var(--dim); letter-spacing: .1em; }

.hero-banner { max-width: 1180px; margin: 72px auto 0; padding: 0 24px; }
.hero-banner img { width: 100%; border: 1px solid var(--hair); border-top: 0; }

/* ---------- 关于 ---------- */
.about-grid {
  display: grid; grid-template-columns: 1.15fr .85fr;
  gap: 56px; align-items: start;
}
.about-txt p { margin-bottom: 18px; font-size: 16.5px; }
.about-txt strong { color: var(--royal); }
.about-txt em { font-style: normal; border-bottom: 3px solid rgba(0, 56, 215, .35); }
.about-note {
  font-family: var(--font-mono); font-size: 13.5px !important;
  color: #4A55A8; border-left: 3px solid var(--royal);
  padding-left: 14px;
}
.about-visual { max-width: 430px; justify-self: end; }
.about-visual img { border: 1px solid var(--hair-ice); border-top: 0; }

/* 海报放大 */
.poster-zoom {
  position: relative; display: block; width: 100%;
  padding: 0; border: 0; background: none; cursor: zoom-in;
}
.poster-zoom img { transition: filter .2s; }
.poster-zoom:hover img { filter: brightness(1.06); }
.zoom-hint {
  position: absolute; left: 12px; bottom: 12px;
  font-family: var(--font-mono); font-size: 12px;
  color: #fff; background: rgba(5, 11, 74, .78);
  padding: 6px 10px; border: 1px solid rgba(255, 255, 255, .35);
  opacity: 0; transition: opacity .2s;
  pointer-events: none;
}
.poster-zoom:hover .zoom-hint,
.poster-zoom:focus-visible .zoom-hint { opacity: 1; }

/* 海报灯箱 */
.lightbox {
  position: fixed; inset: 0; z-index: 130;
  background: rgba(0, 4, 46, .92);
  display: none; align-items: center; justify-content: center;
  padding: 24px; cursor: zoom-out;
}
.lightbox.open { display: flex; }
.lightbox img {
  max-width: min(92vw, 900px); max-height: 92vh;
  width: auto; height: auto;
  border: 1px solid var(--hair);
  box-shadow: 0 0 60px rgba(77, 93, 240, .4);
}
.lightbox-close {
  position: absolute; top: 18px; right: 22px;
  width: 46px; height: 46px;
  font-size: 20px; line-height: 1;
  color: var(--ice); background: none;
  border: 1px solid var(--hair); cursor: pointer;
}
.lightbox-close:hover { border-color: var(--cyan); color: var(--cyan); }

/* ---------- 职责 ---------- */
.duty-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px;
}
.duty {
  position: relative; overflow: hidden;
  border: 1px solid var(--hair);
  padding: 26px 22px;
  transition: border-color .2s, transform .2s, background .2s;
}
.duty:hover { border-color: var(--cyan); background: rgba(0, 6, 92, .5); transform: translateY(-4px); }
.duty-top { display: flex; align-items: flex-start; justify-content: space-between; gap: 12px; }
.duty-logo { width: 52px; height: auto; max-height: 52px; object-fit: contain; opacity: .92; flex-shrink: 0; }
.duty-tag { font-family: var(--font-mono); font-size: 13px; color: var(--cyan); letter-spacing: .12em; margin-bottom: 14px; }
.duty h3 { font-size: 20px; font-weight: 800; margin-bottom: 12px; letter-spacing: .04em; }
.duty p { font-size: 14.5px; color: var(--dim); line-height: 1.8; }
.duty-skill {
  margin-top: 16px; font-family: var(--font-mono);
  font-size: 12px !important; color: #7C8AE0 !important;
  border-top: 1px dashed var(--hair); padding-top: 12px;
}
.duty-new {
  font-family: var(--font-mono); font-size: 11px; font-weight: 400;
  color: var(--cyan); border: 1px solid var(--cyan);
  padding: 2px 7px; vertical-align: 3px; margin-left: 6px;
  letter-spacing: .08em;
}

/* ---------- 双十 ---------- */
.fact-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 28px;
}
.fact { border-top: 3px solid var(--royal); padding-top: 18px; }
.fact-num {
  font-size: clamp(20px, 2.4vw, 27px); font-weight: 900;
  color: var(--deep); margin-bottom: 8px; letter-spacing: .02em;
}
.fact-txt { font-size: 14px; color: #39418C; line-height: 1.8; }
.anthem {
  margin-top: 64px; border-left: 4px solid var(--royal);
  padding: 6px 0 6px 22px; max-width: 720px;
}
.anthem p { font-size: 18px; font-weight: 600; color: var(--ink); line-height: 2; }
.anthem cite { font-style: normal; font-family: var(--font-mono); font-size: 13px; color: #5A64A8; }

/* ---------- 动态 ---------- */
.loglist { list-style: none; }
.log {
  display: flex; align-items: baseline; gap: 18px;
  padding: 20px 4px; border-bottom: 1px solid var(--hair);
}
.log time { font-family: var(--font-mono); font-size: 13.5px; color: var(--dim); flex-shrink: 0; }
.log-tag { font-family: var(--font-mono); font-size: 13px; color: var(--cyan); flex-shrink: 0; }
.log p { font-size: 16px; color: var(--ice); }

/* ---------- 纳新 ---------- */
.sec-join { background: var(--deep); }
.sec-join::before { opacity: .65; }
.h2-join { color: #fff; }
.join-grid {
  max-width: 860px;
}
.term { border: 1px solid var(--hair); border-top: 0; }
.term .win-bar { border-left: 0; border-right: 0; }
.term-body {
  font-family: var(--font-mono); font-size: 14.5px; line-height: 2.05;
  color: #C6D2FF; padding: 26px 26px 10px;
  min-height: 300px; white-space: pre-wrap; word-break: break-all;
}
.term-body::after {
  content: "▌"; color: var(--cyan);
  animation: blink 1s steps(1) infinite;
}
@keyframes blink { 50% { opacity: 0; } }
/* 桌面端终端被 pin：按满文本锁定高度，打字过程中布局恒定，pin 占位不漂移 */
@media (min-width: 981px) {
  html.gsap-on .term-body { height: 396px; min-height: 0; }
}
.term-cta { padding: 18px 26px 26px; }
.term-qq {
  font-family: var(--font-mono); font-size: 14.5px;
  color: var(--dim); margin-bottom: 16px; letter-spacing: .04em;
}
.term-qq b { color: var(--cyan); font-size: 17px; letter-spacing: .06em; }
.term-btns { display: flex; gap: 14px; flex-wrap: wrap; }

/* 纳新流程 */
.flow {
  list-style: none;
  display: flex; flex-wrap: wrap; gap: 12px 28px;
  margin-top: 44px; padding: 18px 22px;
  border: 1px dashed var(--hair);
}
.flow li { font-size: 15px; color: var(--dim); letter-spacing: .06em; }
.flow li b {
  font-family: var(--font-mono); font-weight: 700;
  color: var(--cyan); margin-right: 8px;
}

/* ---------- 联系 ---------- */
.contact-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 28px;
}
.contact-item { border-top: 1px solid var(--hair-ice); padding-top: 18px; }
.contact-k {
  font-family: var(--font-mono); font-size: 12.5px;
  color: var(--royal); letter-spacing: .14em; margin-bottom: 10px;
}
.contact-v { font-size: 15px; color: #232C74; }

/* ---------- 页脚 ---------- */
.footer {
  background: var(--deep);
  border-top: 1px solid var(--hair);
  padding: 72px 0 56px;
}
.footer-grid {
  display: grid; grid-template-columns: 1.1fr 1fr;
  gap: 56px; align-items: start;
}
.footer-brand { text-align: left; }
.footer-emblem { width: 54px; margin: 0 0 20px; opacity: .85; }
.footer-brand p { font-size: 14px; color: var(--dim); }
.footer-small { margin-top: 6px; font-family: var(--font-mono); font-size: 12px !important; color: #5F6BC4 !important; letter-spacing: .06em; }

.footer-links { border-left: 1px solid var(--hair); padding-left: 40px; }
.footer-split {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 28px 36px; align-items: start;
}
.footer-k {
  font-family: var(--font-mono); font-size: 12px;
  color: var(--cyan); letter-spacing: .14em; margin-bottom: 16px;
}
.footer-list { list-style: none; padding: 0; margin: 0; }
.footer-list li { break-inside: avoid; }
.footer-list a {
  display: inline-block; padding: 5px 0;
  font-size: 13.5px; color: var(--dim);
  transition: color .15s;
}
.footer-list a::after { content: " ↗"; font-family: var(--font-mono); font-size: 11px; color: #5F6BC4; transition: color .15s; }
.footer-list a:hover { color: var(--cyan); }
.footer-list a:hover::after { color: var(--cyan); }
.footer-nm {
  grid-column: 1 / -1; margin-top: 0;
  font-size: 12.5px; color: #5F6BC4;
  font-family: var(--font-mono); letter-spacing: .04em;
}
/* 备案行高亮 */
.footer-icp a,
.bd-foot-icp a,
.foot-note a[href*="beian"],
.rail-note a[href*="beian"] {
  color: var(--cyan) !important;
  font-weight: 600;
}
.footer-icp a:hover,
.bd-foot-icp a:hover,
.foot-note a[href*="beian"]:hover,
.rail-note a[href*="beian"]:hover {
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 滚动显现 ---------- */
@media (prefers-reduced-motion: no-preference) {
  .reveal { opacity: 0; transform: translateY(20px); transition: opacity .7s ease, transform .7s ease; }
  .reveal.is-in { opacity: 1; transform: none; }
  .reveal[data-delay="1"] { transition-delay: .12s; }
  .reveal[data-delay="2"] { transition-delay: .24s; }
  .reveal[data-delay="3"] { transition-delay: .36s; }
  .reveal[data-delay="4"] { transition-delay: .48s; }
  .reveal[data-delay="5"] { transition-delay: .6s; }
}

/* ---------- 引导式动效 ---------- */
.scroll-progress {
  position: absolute; top: 0; left: 0; z-index: 5;
  height: 2px; width: 0;
  background: linear-gradient(90deg, var(--royal), var(--cyan));
  pointer-events: none;
}
.scroll-cue {
  display: inline-block; margin-top: 48px;
  font-family: var(--font-mono); font-size: 13px;
  color: var(--dim); letter-spacing: .28em;
  transition: color .2s;
}
.scroll-cue:hover { color: var(--cyan); }

.rail {
  position: fixed; right: 22px; top: 50%; z-index: 40;
  transform: translateY(-50%);
  display: flex; flex-direction: column; gap: 20px;
}
.rail-link { display: flex; align-items: center; justify-content: flex-end; gap: 10px; min-height: 20px; }
.rail-link span {
  font-family: var(--font-mono); font-size: 11px; letter-spacing: .2em;
  color: var(--dim); opacity: 0; transform: translateX(6px);
  transition: opacity .2s, transform .2s, color .2s;
}
.rail-link i {
  width: 9px; height: 9px; flex-shrink: 0;
  border: 1px solid var(--dim); background: transparent;
  transform: rotate(45deg);
  transition: background .2s, border-color .2s, box-shadow .2s;
}
.rail-link:hover span, .rail-link:focus-visible span { opacity: 1; transform: none; }
.rail-link.is-active i {
  background: var(--cyan); border-color: var(--cyan);
  box-shadow: 0 0 10px rgba(143, 217, 255, .8);
}
.rail-link.is-active span { opacity: 1; transform: none; color: var(--cyan); }

@media (prefers-reduced-motion: no-preference) {
  .scroll-cue { animation: cueFloat 2.2s ease-in-out infinite; }
  .reveal-x { transform: translateX(-18px); }
  .reveal-x.is-in { transform: none; }
  .reveal-wipe { transform: none; }
  .reveal-wipe img {
    clip-path: inset(0 100% 0 0);
    transition: clip-path 1.15s cubic-bezier(.4, 0, .2, 1) .3s;
  }
  .reveal-wipe.is-in img { clip-path: inset(0 0 0 0); }
  .duty::after {
    content: ""; position: absolute; top: 0; bottom: 0; left: 0; width: 2px;
    background: linear-gradient(180deg, transparent, var(--cyan), transparent);
    opacity: 0; pointer-events: none;
  }
  .duty.is-in::after { animation: scan 1.1s ease-out .2s 1 both; }
  .btn-primary.pulse { animation: ctaPulse 1.5s ease-out 2; }
  .lightbox.open img { animation: lbIn .28s ease-out 1; }
}
@keyframes cueFloat { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(7px); } }
@keyframes scan { 0% { left: 0; opacity: 1; } 90% { opacity: 1; } 100% { left: 100%; opacity: 0; } }
@keyframes ctaPulse {
  0% { box-shadow: 0 0 0 0 rgba(143, 217, 255, .4); }
  100% { box-shadow: 0 0 0 14px rgba(143, 217, 255, 0); }
}
@keyframes lbIn { from { transform: scale(.965); opacity: 0; } }

/* ---------- GSAP 增强模式（JS 检测到库后挂 gsap-on，接管入场动画） ----------
   显隐完全交给 GSAP：此处仅禁用 CSS 过渡防双重动画，
   元素在触发前保持基础隐藏态（opacity 0），杜绝"先可见再闪隐" */
html.gsap-on .reveal,
html.gsap-on .reveal-x,
html.gsap-on .reveal-wipe,
html.gsap-on .reveal-wipe img { transition: none; }
html.gsap-on .poster-zoom { overflow: hidden; }

/* ---------- 反色跟随光标（桌面指针设备，JS 挂 gsap-cursor 后启用） ----------
   圆形 ↔ 磁性矩形（吸附标题/短文本/按钮）由 GSAP 驱动，勿在此加 transition */
html.gsap-cursor, html.gsap-cursor * { cursor: none !important; }
html.gsap-cursor img { cursor: zoom-in !important; }
html.gsap-cursor .lightbox, html.gsap-cursor .lightbox img { cursor: zoom-out !important; }
html.gsap-cursor .brand-logo, html.gsap-cursor .footer-emblem, html.gsap-cursor .duty-logo { cursor: none !important; }
.cursor-dot {
  position: fixed; left: 0; top: 0; z-index: 120;
  width: 108px; height: 108px; border-radius: 60px;
  backdrop-filter: invert(1); -webkit-backdrop-filter: invert(1);
  pointer-events: none; opacity: 0;
  will-change: transform, width, height;
}

/* ---------- 吸附时同步控件的悬浮效果（.is-hover 由光标 JS 维护） ---------- */
.btn-primary.is-hover { background: #fff; border-color: #fff; }
.btn-ghost.is-hover { border-color: var(--cyan); color: var(--cyan); }
.nav-link.is-hover { color: var(--ice); }
.nav-cta.is-hover { background: #fff; }
.rail-link.is-hover span { opacity: 1; transform: none; color: var(--cyan); }
.scroll-cue.is-hover { color: var(--cyan); }
.qq-copy.is-hover { color: #fff; border-bottom-color: #fff; }
.sec-ice .qq-copy.is-hover { color: var(--ink); border-bottom-color: var(--ink); }
.lightbox-close.is-hover { border-color: var(--cyan); color: var(--cyan); }

/* ---------- 操作反馈：按压态 ---------- */
.btn:active { transform: translateY(1px) scale(.98); }
.btn { transition: background .18s, color .18s, border-color .18s, transform .12s; }
.nav-link:active, .nav-cta:active { transform: translateY(1px); }
.burger:active, .lightbox-close:active { transform: scale(.94); }
.rail-link:active i { transform: rotate(45deg) scale(.82); }
.scroll-cue:active { color: var(--cyan); }

/* ---------- 群号复制 ---------- */
.qq-copy {
  font-family: var(--font-mono); font-size: inherit; font-weight: 700;
  color: var(--cyan); background: none;
  border: 0; border-bottom: 1px dashed var(--cyan);
  padding: 0 2px; cursor: copy; letter-spacing: .06em;
  transition: color .15s, border-color .15s, transform .12s;
}
.qq-copy:hover { color: #fff; border-bottom-color: #fff; }
.qq-copy:active { transform: scale(.96); }
.qq-copy:disabled { cursor: default; }
.qq-copy.copied { color: var(--cyan); border-bottom-color: transparent; }
.sec-ice .qq-copy { color: var(--royal); border-bottom-color: var(--royal); }
.sec-ice .qq-copy:hover { color: var(--ink); border-bottom-color: var(--ink); }
.sec-ice .qq-copy.copied { color: var(--royal); }

/* ---------- 响应式 ---------- */
@media (max-width: 1100px) {
  .rail { display: none; }
}
@media (max-width: 980px) {
  .duty-grid { grid-template-columns: repeat(2, 1fr); }
  .fact-grid, .contact-grid { grid-template-columns: repeat(2, 1fr); }
  .about-grid { grid-template-columns: 1fr; }
  .about-visual { justify-self: start; }
}
@media (max-width: 860px) {
  .burger { display: flex; }
  .footer-grid { grid-template-columns: 1fr; gap: 40px; }
  .footer-links { border-left: 0; padding-left: 0; border-top: 1px solid var(--hair); padding-top: 32px; }
  .footer-split { grid-template-columns: 1fr; gap: 28px; }
  .nav {
    display: flex;
    position: fixed; top: var(--header-h); left: 0; right: 0;
    flex-direction: column; align-items: stretch; gap: 0;
    background: var(--deep);
    border-bottom: 1px solid var(--hair);
    padding: 10px 18px 18px;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transform: translateY(-16px) scaleY(0.96);
    transform-origin: top center;
    transition: opacity .4s cubic-bezier(.22,1,.36,1),
      transform .48s cubic-bezier(.34,1.4,.5,1),
      visibility 0s linear .48s;
  }
  .nav.open {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transform: none;
    transition: opacity .4s cubic-bezier(.22,1,.36,1),
      transform .5s cubic-bezier(.34,1.4,.5,1),
      visibility 0s;
  }
  .nav.open .nav-link,
  .nav.open .nav-cta {
    animation: navItemIn .5s cubic-bezier(.22,1,.36,1) both;
  }
  .nav.open .nav-link:nth-child(1) { animation-delay: .05s; }
  .nav.open .nav-link:nth-child(2) { animation-delay: .1s; }
  .nav.open .nav-link:nth-child(3) { animation-delay: .15s; }
  .nav.open .nav-link:nth-child(4) { animation-delay: .2s; }
  .nav.open .nav-link:nth-child(5) { animation-delay: .25s; }
  .nav.open .nav-cta { animation-delay: .3s; }
  @keyframes navItemIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: none; }
  }
  .nav-link { border-bottom: 1px solid var(--hair); border-radius: 0; padding: 14px 6px; }
  .nav-cta { margin: 14px 0 0; justify-content: center; }
}
@media (max-width: 560px) {
  .sec { padding: 72px 0; }
  .hero { padding-top: calc(var(--header-h) + 48px); }
  .hero-stats { grid-template-columns: repeat(2, 1fr); row-gap: 18px; }
  .hero-stats > div:nth-child(3) { border-left: 0; }
  .duty-grid, .fact-grid, .contact-grid { grid-template-columns: 1fr; }
  .log { flex-wrap: wrap; gap: 6px 14px; }
  .brand-text small { display: none; }
  .topbar { padding: 0 16px; }
  .wrap { padding: 0 18px; }
  .hero-banner, .hero-head { padding: 0 18px; }
}

@media (prefers-reduced-motion: reduce) {
  .nav, .nav.open { transition: none; }
  .nav.open .nav-link, .nav.open .nav-cta { animation: none; }
  .burger span { transition: none; }
}