/* =========================================================
   滕博会官网 · 共享站点套件
   路径：/assets/site.css
   仅负责 reset、变量、中文排版、框架式头尾、通用组件
   ========================================================= */

/* ---------- 1. reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;text-size-adjust:100%}
body,h1,h2,h3,h4,h5,h6,p,figure,blockquote,dl,dd,ul,ol,li{margin:0}
ul,ol{list-style:none;padding:0}
img,svg,video,canvas{display:block;max-width:100%}
a{color:inherit;text-decoration:none}
button{font:inherit;color:inherit;background:none;border:0;padding:0;cursor:pointer}
table{border-collapse:collapse;width:100%}
:focus-visible{outline:2px solid var(--orange);outline-offset:2px}

/* ---------- 2. 设计令牌 ---------- */
:root{
  --ink:#0A1A2B;
  --paper:#F3F5F1;
  --sea:#123E63;
  --celadon:#5FA89B;
  --orange:#FF7A2F;
  --blueprint:#C7D5DE;
  --teal-deep:#1E5A50;
  --index-gray:#6E7C88;
  --orange-pale:#FFD8BE;

  --font-title:"Noto Serif SC","Source Han Serif SC","Songti SC",serif;
  --font-body:"Inter","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  --font-mono:"IBM Plex Mono","SFMono-Regular",Consolas,monospace;

  --bar-h:56px;
  --rail-w:148px;

  --hair:1px solid var(--blueprint);
  --rail-line:rgba(199,213,222,.34);
  --rail-line-soft:rgba(199,213,222,.16);
  --shadow-paper:10px 10px 0 -1px var(--paper),10px 10px 0 0 var(--blueprint);
}
@media (min-width:1200px){:root{--rail-w:172px}}
html[data-compact]{--rail-w:128px}

/* ---------- 3. 基础排版 ---------- */
html{
  scroll-padding-top:calc(var(--bar-h) + 20px);
}
@media (prefers-reduced-motion:no-preference){
  html{scroll-behavior:smooth}
}
body{
  min-height:100vh;
  padding-top:var(--bar-h);
  padding-left:var(--rail-w);
  background:var(--paper);
  color:var(--ink);
  font-family:var(--font-body);
  font-size:17px;
  line-height:1.7;
  font-weight:400;
  transition:padding-left .16s ease;
}
[id]{scroll-margin-top:calc(var(--bar-h) + 20px)}
#main-content{display:block;outline:none}
::selection{background:var(--orange-pale);color:var(--ink)}

.t-display{font-family:var(--font-title);font-weight:700;font-size:clamp(34px,4.4vw,52px);line-height:1.18;letter-spacing:-.01em}
.t-h1{font-family:var(--font-title);font-weight:700;font-size:clamp(26px,3vw,34px);line-height:1.24;letter-spacing:-.01em}
.t-h2{font-family:var(--font-title);font-weight:700;font-size:26px;line-height:1.3}
.t-h3{font-size:20px;font-weight:700;line-height:1.4;letter-spacing:.01em}
.lede{font-size:20px;line-height:1.7;color:var(--sea)}
.body-text{font-size:17px;line-height:1.7}
.small{font-size:15px;line-height:1.7}
.mono{font-family:var(--font-mono);letter-spacing:.02em}
.kicker{display:inline-block;font-family:var(--font-mono);font-size:13px;letter-spacing:.12em;color:var(--teal-deep)}
.rule{height:1px;background:var(--blueprint);border:0;margin:0}
.note{font-size:13px;line-height:1.7;color:var(--sea);padding-left:12px;border-left:2px solid var(--celadon)}

.link-u{
  color:var(--sea);
  padding-bottom:2px;
  background-image:linear-gradient(var(--orange),var(--orange));
  background-repeat:no-repeat;
  background-size:0 2px;
  background-position:0 100%;
  transition:background-size .16s ease,color .16s ease;
}
.link-u:hover,.link-u:focus-visible{color:var(--orange);background-size:100% 2px}

/* ---------- 4. 布局 ---------- */
.wrap{width:100%;max-width:1240px;margin-inline:auto;padding-inline:clamp(20px,4vw,48px)}
.grid{display:grid;grid-template-columns:repeat(12,minmax(0,1fr));gap:clamp(16px,2vw,28px)}
.col-3{grid-column:span 3}
.col-4{grid-column:span 4}
.col-5{grid-column:span 5}
.col-6{grid-column:span 6}
.col-7{grid-column:span 7}
.col-8{grid-column:span 8}
.col-9{grid-column:span 9}
@media (max-width:900px){
  .col-3,.col-4,.col-5,.col-6,.col-7,.col-8,.col-9{grid-column:span 12}
}
.section{position:relative;padding:clamp(48px,7vw,96px) 0}
.section--paper{background:var(--paper);color:var(--ink)}
.section--ink{background:var(--ink);color:var(--paper)}
.section--ink .kicker{color:var(--celadon)}
.section--ink .lede{color:var(--blueprint)}
.section--ink .note{color:var(--blueprint);border-left-color:var(--orange)}

/* ---------- 5. 组件 ---------- */
.card{
  position:relative;
  background:var(--paper);
  border:var(--hair);
  padding:clamp(20px,2.4vw,32px);
  box-shadow:var(--shadow-paper);
}
.card--ink{background:var(--ink);color:var(--paper);border-color:var(--sea);box-shadow:none}

.tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:3px 10px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.06em;
  background:rgba(95,168,155,.16);
  color:var(--teal-deep);
  border:1px solid rgba(95,168,155,.5);
}
.tag--orange{background:var(--orange-pale);border-color:var(--orange);color:var(--ink)}

.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  min-height:46px;padding:0 22px;
  font-size:15px;font-weight:700;line-height:1;
  background:var(--paper);color:var(--ink);
  border:1px solid var(--ink);
  transition:background-color .14s ease,color .14s ease,border-color .14s ease;
}
.btn:hover{background:var(--ink);color:var(--paper);border-color:var(--ink)}
.btn--primary{background:var(--orange);border-color:var(--orange);color:var(--ink)}
.btn--primary:hover{background:var(--ink);border-color:var(--ink);color:var(--paper)}
.btn--ghost{background:transparent;border-color:var(--blueprint);color:var(--sea)}
.btn--ghost:hover{background:var(--sea);border-color:var(--sea);color:var(--paper)}
.btn--light{background:transparent;border-color:var(--blueprint);color:var(--paper)}
.btn--light:hover{background:var(--paper);border-color:var(--paper);color:var(--ink)}

.crumbs{display:flex;flex-wrap:wrap;align-items:center;gap:4px 10px;font-family:var(--font-mono);font-size:12px;color:var(--sea)}
.crumbs li{display:inline-flex;align-items:center;gap:4px 10px}
.crumbs li+li::before{content:"/";color:var(--index-gray)}
.crumbs a{color:var(--sea);border-bottom:1px solid var(--blueprint);transition:color .14s ease,border-color .14s ease}
.crumbs a:hover{color:var(--orange);border-bottom-color:var(--orange)}

/* 图片容器基础规则（页面阶段放入 <img> 即可） */
.media{
  position:relative;display:block;width:100%;
  background:var(--blueprint);
  border:var(--hair);
  overflow:hidden;
}
.media::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  background-image:repeating-linear-gradient(45deg,rgba(18,62,99,.10) 0 1px,transparent 1px 9px);
}
.media>img,.media>svg,.media>picture>img{width:100%;height:100%;object-fit:cover}
.media--16x9{aspect-ratio:16/9}
.media--4x3{aspect-ratio:4/3}
.media--1x1{aspect-ratio:1/1}
.media--3x4{aspect-ratio:3/4}
.media--wide{aspect-ratio:21/9}
@media (max-width:600px){
  .media--wide{aspect-ratio:16/9}
  .media--3x4{aspect-ratio:4/3}
}
.media__caption{
  display:block;margin-top:10px;
  font-family:var(--font-mono);font-size:12px;color:var(--sea);
}

/* 显现（由 JS 加 .reveal-init） */
.reveal-init{
  opacity:0;transform:translateY(14px);
  transition:opacity .42s ease var(--reveal-delay,0ms),transform .42s ease var(--reveal-delay,0ms);
}
.reveal-init.is-in{opacity:1;transform:none}

/* ---------- 6. 跳过链接 ---------- */
.skip-link{
  position:fixed;top:10px;left:10px;z-index:200;
  transform:translateY(-220%);
  padding:12px 20px;
  background:var(--orange);color:var(--ink);
  border:1px solid var(--ink);
  font-size:15px;font-weight:700;
  transition:transform .16s ease;
}
.skip-link:focus{transform:translateY(0)}

/* ---------- 7. 框架式头部 ---------- */
.site-frame{position:relative;z-index:70}

/* 7.1 顶部横带 */
.frame-bar{
  position:fixed;top:0;left:var(--rail-w);right:0;
  height:var(--bar-h);
  display:flex;align-items:center;gap:clamp(12px,2vw,26px);
  padding:0 clamp(16px,3vw,40px);
  background:var(--paper);
  border-bottom:var(--hair);
  z-index:65;
  transition:left .16s ease;
}
.bar-brand{display:none;align-items:center;gap:8px;font-family:var(--font-title);font-size:17px;font-weight:700;color:var(--ink);white-space:nowrap}
.bar-brand__mark{display:inline-grid;place-items:center;width:26px;height:26px;background:var(--ink);color:var(--paper);font-family:var(--font-body);font-size:13px;font-weight:700;line-height:1}
.bar-brand__text{display:inline-block}
.bar-meta{
  position:relative;flex:1 1 auto;min-width:0;
  padding-left:16px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.08em;color:var(--sea);
  white-space:nowrap;overflow:hidden;text-overflow:ellipsis;
}
.bar-meta::before{
  content:"";position:absolute;left:0;top:50%;width:8px;height:8px;
  margin-top:-4px;background:var(--celadon);
}
.bar-cta{
  margin-left:auto;display:inline-flex;align-items:center;
  min-height:34px;padding:0 14px;
  font-size:13px;font-weight:700;color:var(--ink);
  border:1px solid var(--ink);
  transition:background-color .14s ease,color .14s ease,border-color .14s ease;
}
.bar-cta:hover{background:var(--orange);border-color:var(--orange);color:var(--ink)}

.nav-toggle{
  display:none;align-items:center;gap:10px;
  margin-left:auto;min-height:44px;min-width:44px;padding:0 14px;
  background:var(--ink);color:var(--paper);
  border:1px solid var(--ink);
  font-size:13px;font-weight:700;
  transition:background-color .14s ease,color .14s ease;
}
.nav-toggle:hover{background:var(--sea)}
.nav-toggle__bars{position:relative;display:block;width:18px;height:2px;background:currentColor;transition:background-color .16s ease}
.nav-toggle__bars::before,.nav-toggle__bars::after{content:"";position:absolute;left:0;width:18px;height:2px;background:currentColor;transition:transform .16s ease}
.nav-toggle__bars::before{top:-6px}
.nav-toggle__bars::after{top:6px}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars{background:transparent}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before{transform:translateY(6px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after{transform:translateY(-6px) rotate(-45deg)}
.nav-toggle__text{display:inline-block}

/* 7.2 左侧栏目条 */
.frame-rail{
  position:fixed;top:0;left:0;bottom:0;width:var(--rail-w);
  display:flex;flex-direction:column;gap:18px;
  padding:22px 12px 18px;
  background:var(--ink);color:var(--paper);
  border-right:1px solid var(--blueprint);
  overflow-y:auto;overscroll-behavior:contain;
  z-index:70;
  transition:width .16s ease,transform .18s ease,visibility .18s ease;
}
.frame-rail::before{
  content:"";position:absolute;top:0;left:0;right:0;height:3px;background:var(--celadon);
}
.rail-brand{display:block;padding:10px 8px 14px;border-bottom:1px solid var(--rail-line)}
.rail-brand__name{display:block;font-family:var(--font-title);font-size:20px;font-weight:700;line-height:1.3;letter-spacing:.02em}
.rail-brand__line{display:block;margin-top:6px;font-family:var(--font-mono);font-size:11px;line-height:1.6;letter-spacing:.04em;color:var(--celadon)}
.rail-nav{flex:1 1 auto}
.rail-list{display:flex;flex-direction:column;gap:2px}
.rail-item{display:block}
.rail-link{
  display:flex;align-items:center;gap:10px;
  min-height:44px;padding:8px 10px;
  border:1px solid transparent;
  border-left:3px solid var(--rail-line);
  color:var(--paper);font-size:15px;font-weight:500;
  transition:background-color .14s ease,color .14s ease,border-color .14s ease;
}
.rail-link:hover{background:rgba(95,168,155,.18);border-left-color:var(--celadon);color:#fff}
.rail-link[aria-current="page"]{
  background:rgba(255,122,47,.14);
  border-color:rgba(255,122,47,.6);
  border-left-color:var(--orange);
  color:#fff;font-weight:700;
}
.rail-num{font-family:var(--font-mono);font-size:11px;letter-spacing:.02em;color:var(--celadon);flex:0 0 auto}
.rail-link[aria-current="page"] .rail-num{color:var(--orange)}
.rail-label{white-space:nowrap;overflow:hidden;text-overflow:ellipsis}

.rail-jump{padding-top:12px}
.rail-jump__link{
  display:inline-flex;align-items:center;gap:6px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.04em;
  color:var(--celadon);
  border-bottom:1px solid transparent;
  transition:color .14s ease,border-color .14s ease;
}
.rail-jump__link::before{content:"›";font-size:14px}
.rail-jump__link:hover{color:var(--orange);border-bottom-color:var(--orange)}

.rail-quick{
  display:flex;flex-direction:column;gap:6px;
  padding-top:14px;
  border-top:1px solid var(--rail-line);
}
.rail-quick__item{display:block}
.fold-label{
  position:relative;display:block;
  min-height:34px;padding:8px 10px;
  background:rgba(199,213,222,.10);
  border:1px solid var(--rail-line);
  color:var(--paper);
  font-size:13px;line-height:1.35;
  transition:background-color .14s ease,color .14s ease,border-color .14s ease;
}
.fold-label::after{
  content:"";position:absolute;top:-1px;right:-1px;
  border-style:solid;border-width:0 9px 9px 0;
  border-color:transparent var(--ink) transparent transparent;
}
.fold-label:hover{background:var(--orange);border-color:var(--orange);color:var(--ink)}

/* 收窄态 */
html[data-compact] .rail-brand{padding:8px 6px 12px}
html[data-compact] .rail-brand__name{font-size:17px}
html[data-compact] .rail-brand__line{display:none}
html[data-compact] .frame-rail{padding:20px 12px 16px;gap:14px}
html[data-compact] .rail-link{min-height:40px;padding:7px 6px;border-left-width:2px;gap:6px;font-size:13px}
html[data-compact] .rail-num{font-size:10px}
html[data-compact] .rail-label{letter-spacing:0}
html[data-compact] .fold-label{padding:7px 8px;font-size:12px}
html[data-compact] .fold-label::after{border-width:0 7px 7px 0}
html[data-compact] .rail-quick{gap:5px;padding-top:12px}

/* 遮罩 */
.nav-scrim{
  position:fixed;inset:0;
  background:rgba(10,26,43,.6);
  opacity:0;visibility:hidden;
  transition:opacity .18s ease,visibility .18s ease;
  z-index:60;
}
body[data-nav-open] .nav-scrim{opacity:1;visibility:visible}

/* ---------- 8. 页脚 ---------- */
.site-foot{
  margin-top:clamp(56px,8vw,112px);
  background:var(--ink);
  color:var(--paper);
  border-top:3px solid var(--celadon);
}
.foot-wrap{
  max-width:1240px;margin-inline:auto;
  padding:clamp(36px,5vw,64px) clamp(20px,4vw,48px) 0;
}
.foot-top{
  display:grid;
  grid-template-columns:minmax(200px,1fr) minmax(0,1.5fr);
  gap:clamp(24px,4vw,56px);
  padding-bottom:clamp(24px,3vw,40px);
  border-bottom:1px solid var(--rail-line);
}
.foot-brand__link{display:inline-block;font-family:var(--font-title);font-size:26px;font-weight:700;line-height:1.3;color:var(--paper)}
.foot-brand__link:hover{color:var(--orange)}
.foot-brand__line{margin-top:10px;font-size:15px;color:var(--blueprint)}
.foot-brand__mono{margin-top:12px;font-family:var(--font-mono);font-size:12px;letter-spacing:.1em;color:var(--celadon)}

.foot-nav__list{
  display:grid;grid-template-columns:repeat(2,minmax(0,1fr));
  gap:1px;background:var(--rail-line-soft);
  border:1px solid var(--rail-line-soft);
}
.foot-nav__list li{background:var(--ink)}
.foot-nav__list a{
  display:flex;align-items:center;
  min-height:60px;padding:0 16px;
  font-size:15px;color:var(--paper);
  transition:background-color .14s ease,color .14s ease,padding-left .14s ease;
}
.foot-nav__list a:hover{background:var(--sea);color:#fff;padding-left:22px}

.foot-mid{padding:clamp(24px,3vw,40px) 0 0}
.foot-kicker{
  font-family:var(--font-mono);font-size:12px;letter-spacing:.14em;
  color:var(--celadon);
  margin-bottom:14px;
}
.foot-contact{
  display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));
  gap:0 clamp(24px,4vw,56px);
}
.foot-contact__item{
  display:flex;flex-wrap:wrap;align-items:center;gap:10px;
  padding:12px 0;
  border-top:1px solid var(--rail-line-soft);
}
.foot-contact__label{
  flex:0 0 auto;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.12em;
  color:var(--celadon);
}
.foot-contact__value{font-size:15px;line-height:1.6;color:var(--paper);word-break:break-all}
.foot-contact__value--mono{font-family:var(--font-mono);letter-spacing:.02em}
.copy-btn{
  display:inline-flex;align-items:center;
  min-height:32px;padding:0 12px;
  background:transparent;color:var(--paper);
  border:1px solid var(--rail-line);
  font-family:var(--font-mono);font-size:12px;letter-spacing:.04em;
  transition:background-color .14s ease,color .14s ease,border-color .14s ease;
}
.copy-btn:hover{background:var(--celadon);border-color:var(--celadon);color:var(--ink)}
.copy-btn[data-copied]{background:var(--orange);border-color:var(--orange);color:var(--ink)}
.foot-tip{margin-top:16px;font-size:13px;line-height:1.7;color:var(--blueprint)}

.foot-legal{
  display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;
  gap:14px 28px;
  margin-top:clamp(24px,3vw,40px);
  padding:20px 0 28px;
  border-top:1px solid var(--rail-line);
}
.foot-legal__links{display:flex;flex-wrap:wrap;gap:10px 24px}
.foot-legal__links a{
  font-size:13px;color:var(--blueprint);
  border-bottom:1px solid transparent;
  transition:color .14s ease,border-color .14s ease;
}
.foot-legal__links a:hover{color:var(--orange);border-bottom-color:var(--orange)}
.foot-legal__meta{
  display:flex;flex-wrap:wrap;gap:10px 20px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.02em;
  color:var(--blueprint);
}
.foot-icp{display:inline-block}
.foot-copy{display:inline-block}

/* ---------- 9. 响应式：平板与手机 ---------- */
@media (max-width:1099px) and (min-width:961px){
  .rail-brand__name{font-size:18px}
}

@media (max-width:960px){
  :root{--rail-w:0px}
  html[data-compact]{--rail-w:0px}

  body{padding-left:0}
  body[data-nav-open]{overflow:hidden}

  .frame-bar{left:0}
  .bar-brand{display:inline-flex}
  .bar-meta{display:none}
  .bar-cta{display:none}
  .nav-toggle{display:inline-flex}

  .frame-rail{
    width:min(320px,86vw);
    transform:translateX(-100%);
    visibility:hidden;
    box-shadow:12px 0 0 0 rgba(10,26,43,.10);
  }
  .frame-rail[data-nav][data-open]{transform:translateX(0);visibility:visible}
  html[data-compact] .rail-brand__line{display:block}
  html[data-compact] .rail-link{font-size:15px;min-height:44px;padding:8px 10px;border-left-width:3px;gap:10px}
  html[data-compact] .rail-num{font-size:11px}
  html[data-compact] .fold-label{font-size:13px;padding:8px 10px}
  html[data-compact] .rail-brand__name{font-size:20px}
}

@media (min-width:700px) and (max-width:960px){
  .bar-meta{display:block}
  .bar-cta{display:inline-flex}
  .bar-brand{font-size:16px}
}

@media (min-width:520px) and (max-width:699px){
  .bar-cta{display:inline-flex}
}

@media (max-width:820px){
  .foot-top{grid-template-columns:1fr}
  .foot-brand__link{font-size:22px}
}
@media (max-width:520px){
  body{font-size:15px}
  .lede{font-size:17px}
  .foot-nav__list{grid-template-columns:1fr}
  .foot-contact{grid-template-columns:1fr}
  .foot-legal{flex-direction:column;align-items:flex-start}
}

/* ---------- 10. 无障碍：焦点与降低动态 ---------- */
a:focus-visible,button:focus-visible,[tabindex]:focus-visible{
  outline:2px solid var(--orange);
  outline-offset:2px;
}
.section--ink a:focus-visible,.site-foot a:focus-visible,.site-foot button:focus-visible,.frame-rail a:focus-visible{
  outline-color:var(--orange-pale);
}

@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
    transition-delay:0ms !important;
    scroll-behavior:auto !important;
  }
  .reveal-init{opacity:1 !important;transform:none !important}
  html{scroll-behavior:auto}
}