:root{
  --ink:#12100F;
  --ink-2:#1E1B19;
  --ink-3:#191614;
  --line:#2C2724;
  --lava:#FF5A1F;
  --ember:#FFA45C;
  --sky:#4FA8D8;
  --flag-yellow:#F2C230;
  --flag-green:#3FA57C;
  --flag-red:#D93A2B;
  --paper:#F4EFE7;
  --ash:#C9BFB2;
  --dim:#9C9187;
  --rail:88px;
  --gutter:clamp(18px,4vw,52px);
  --radius:2px;
  --ease:cubic-bezier(.22,.61,.36,1);
  --sans:"Noto Sans SC","Source Han Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",sans-serif;
  --mono:"JetBrains Mono","IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
}

*,*::before,*::after{box-sizing:border-box}

html{
  -webkit-text-size-adjust:100%;
  scroll-behavior:smooth;
  background:var(--ink);
}

body{
  margin:0;
  padding:0;
  background:var(--ink);
  color:var(--paper);
  font-family:var(--sans);
  font-size:17px;
  line-height:1.75;
  overflow-wrap:break-word;
  -webkit-font-smoothing:antialiased;
}

img,svg,video{max-width:100%}
img{display:block}

h1,h2,h3,h4,h5{
  margin:0;
  color:var(--paper);
  font-weight:900;
  line-height:1.06;
  letter-spacing:-.02em;
}
h1{font-size:clamp(2.6rem,7vw,5.4rem)}
h2{font-size:clamp(1.8rem,3.6vw,3rem)}
h3{font-size:clamp(1.15rem,1.8vw,1.5rem);line-height:1.28}
h4{font-size:1.05rem;line-height:1.4;letter-spacing:0}

p{margin:0 0 1.1em}
p:last-child{margin-bottom:0}

a{color:inherit}
ul,ol{margin:0 0 1.1em;padding-left:1.25em}

::selection{background:var(--lava);color:#12100F}

:focus-visible{
  outline:2px solid var(--lava);
  outline-offset:3px;
  border-radius:1px;
}

#main-content:focus{outline:none}

/* ---------- 通用工具组件 ---------- */
.wrap{
  width:100%;
  max-width:1280px;
  margin:0 auto;
  padding:0 var(--gutter);
}

.section{padding:clamp(56px,9vw,120px) 0}

.eyebrow{
  display:inline-block;
  margin:0 0 14px;
  font-family:var(--mono);
  font-size:11px;
  font-weight:500;
  letter-spacing:.22em;
  color:var(--lava);
  text-transform:uppercase;
}

.rule{
  display:block;
  width:100%;
  height:1px;
  margin:0;
  border:0;
  background:var(--line);
}

.num{
  font-family:var(--mono);
  font-variant-numeric:tabular-nums;
  font-feature-settings:"tnum" 1;
  letter-spacing:-.01em;
}

.prose{max-width:38em}
.prose p{max-width:38em}
.prose a{
  color:var(--sky);
  text-decoration:none;
  border-bottom:1px solid rgba(79,168,216,.45);
}
.prose a:hover{border-bottom-color:var(--sky)}

.breadcrumb{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:8px;
  padding:26px 0 0;
  font-family:var(--mono);
  font-size:11px;
  letter-spacing:.14em;
  color:var(--dim);
}
.breadcrumb a{
  color:var(--ash);
  text-decoration:none;
  transition:color .2s var(--ease);
}
.breadcrumb a:hover{color:var(--lava)}
.breadcrumb__sep{color:var(--line)}

/* ---------- 按钮 ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  min-height:44px;
  padding:11px 20px;
  border:1px solid var(--line);
  border-radius:var(--radius);
  background:transparent;
  color:var(--paper);
  font-family:var(--sans);
  font-size:13px;
  font-weight:700;
  letter-spacing:.08em;
  line-height:1.15;
  text-decoration:none;
  cursor:pointer;
  transition:background .2s var(--ease),color .2s var(--ease),border-color .2s var(--ease),transform .2s var(--ease);
}
.btn:hover{transform:translateY(-1px)}
.btn--ghost:hover{border-color:var(--lava);color:var(--lava)}
.btn--solid{
  background:var(--lava);
  border-color:var(--lava);
  color:#12100F;
}
.btn--solid:hover{
  background:var(--ember);
  border-color:var(--ember);
}

/* ---------- 标签 ---------- */
.chip{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:3px 9px;
  border:1px solid var(--line);
  border-radius:var(--radius);
  background:rgba(44,39,36,.45);
  font-family:var(--mono);
  font-size:11px;
  letter-spacing:.1em;
  line-height:1.5;
  color:var(--ash);
  white-space:nowrap;
}
.chip--lava{border-color:rgba(255,90,31,.55);color:var(--ember);background:rgba(255,90,31,.1)}
.chip--sky{border-color:rgba(79,168,216,.55);color:var(--sky);background:rgba(79,168,216,.1)}
.chip--yellow{border-color:rgba(242,194,48,.55);color:var(--flag-yellow);background:rgba(242,194,48,.1)}
.chip--green{border-color:rgba(63,165,124,.55);color:var(--flag-green);background:rgba(63,165,124,.1)}
.chip--red{border-color:rgba(217,58,43,.6);color:#F0705F;background:rgba(217,58,43,.12)}

/* ---------- 研究板卡片 ---------- */
.board{
  position:relative;
  padding:clamp(18px,2.4vw,26px);
  background:var(--ink-2);
  border:1px solid var(--line);
  border-radius:var(--radius);
}
.board > :first-child{margin-top:0}
.board--stack::before{
  content:"";
  position:absolute;
  left:8px;
  right:-8px;
  top:8px;
  bottom:-8px;
  border:1px solid var(--line);
  border-radius:var(--radius);
  pointer-events:none;
}

/* ---------- 图片容器 ---------- */
.media{
  position:relative;
  display:block;
  overflow:hidden;
  background:var(--ink-3);
  border:1px solid var(--line);
  border-radius:var(--radius);
}
.media--16x10{aspect-ratio:16/10}
.media--4x5{aspect-ratio:4/5}
.media--cut{clip-path:polygon(0 0,100% 5%,100% 100%,0 95%)}
.media img,.media video{
  width:100%;
  height:100%;
  object-fit:cover;
}
.media__tag{
  position:absolute;
  top:10px;
  left:10px;
  padding:4px 8px;
  background:rgba(18,16,15,.86);
  border:1px solid var(--line);
  font-family:var(--mono);
  font-size:10px;
  letter-spacing:.14em;
  color:var(--ember);
}
.media__caption{
  margin:10px 0 0;
  font-family:var(--mono);
  font-size:11px;
  letter-spacing:.1em;
  color:var(--dim);
}

/* ---------- 反色翻页区块 ---------- */
.flip{
  background:var(--paper);
  color:var(--ink);
}
.flip h1,.flip h2,.flip h3,.flip h4{color:var(--ink)}
.flip .eyebrow{color:#B53C0D}
.flip .rule{background:#D8CFC2}
.flip .chip{
  background:rgba(18,16,15,.04);
  border-color:#CFC5B7;
  color:#5A5147;
}

/* ---------- 跳转链接 ---------- */
.skip-link{
  position:fixed;
  top:0;
  left:0;
  z-index:200;
  padding:14px 20px;
  background:var(--lava);
  color:#12100F;
  font-family:var(--sans);
  font-size:13px;
  font-weight:700;
  letter-spacing:.14em;
  text-decoration:none;
  transform:translateY(-180%);
  transition:transform .18s var(--ease);
}
.skip-link:focus,
.skip-link:focus-visible{
  transform:translateY(0);
  outline:2px solid var(--paper);
  outline-offset:2px;
}

/* ---------- 头部：左侧竖排框架 ---------- */
.site-header{
  position:fixed;
  top:0;
  left:0;
  bottom:0;
  width:var(--rail);
  display:flex;
  flex-direction:column;
  align-items:center;
  padding:22px 0 18px;
  background:var(--ink-2);
  border-right:1px solid var(--line);
  z-index:100;
  overflow-y:auto;
  overflow-x:hidden;
  scrollbar-width:none;
}
.site-header::-webkit-scrollbar{display:none}

.brand{
  display:flex;
  flex-direction:column;
  align-items:center;
  gap:12px;
  padding:0 0 6px;
}
.brand__mark{
  writing-mode:vertical-rl;
  font-size:19px;
  font-weight:900;
  line-height:1;
  letter-spacing:.16em;
  color:var(--paper);
  text-decoration:none;
  transition:color .2s var(--ease);
}
.brand__mark:hover{color:var(--ember)}
.brand__rule{
  display:block;
  width:3px;
  height:34px;
  background:var(--lava);
}
.brand__tag{
  margin:0;
  writing-mode:vertical-rl;
  font-size:10px;
  line-height:1.25;
  letter-spacing:.06em;
  color:var(--dim);
}

.nav-toggle{display:none}

.site-nav{
  display:flex;
  flex-direction:column;
  justify-content:center;
  gap:22px;
  width:100%;
  margin:26px 0 0;
  flex:1 1 auto;
}
.site-nav__list{
  display:flex;
  flex-direction:column;
  gap:1px;
  margin:0;
  padding:0 6px;
  list-style:none;
}
.site-nav__item{display:block}
.site-nav__link{
  display:flex;
  flex-direction:column;
  gap:2px;
  padding:7px 4px 8px 10px;
  border-left:2px solid transparent;
  color:var(--ash);
  font-size:12px;
  line-height:1.2;
  letter-spacing:.04em;
  text-decoration:none;
  transition:color .2s var(--ease),background .2s var(--ease),border-color .2s var(--ease);
}
.site-nav__idx{
  font-family:var(--mono);
  font-size:9px;
  letter-spacing:.1em;
  color:#6B625A;
  transition:color .2s var(--ease);
}
.site-nav__label{display:block}
.site-nav__link:hover{
  color:var(--paper);
  background:rgba(255,90,31,.09);
}
.site-nav__link[aria-current="page"]{
  color:var(--paper);
  border-left-color:var(--lava);
  background:rgba(255,90,31,.12);
}
.site-nav__link[aria-current="page"] .site-nav__idx{color:var(--lava)}

.header-actions{
  display:flex;
  flex-direction:column;
  align-items:center;
  gap:12px;
  padding:0 8px;
}
.site-header .header-actions .btn{
  writing-mode:vertical-rl;
  justify-content:center;
  width:36px;
  min-height:0;
  padding:14px 0;
  font-size:11px;
  letter-spacing:.2em;
  line-height:1;
}

/* ---------- 滚动进度 ---------- */
.scroll-meter{
  position:fixed;
  top:0;
  right:0;
  width:3px;
  height:100vh;
  pointer-events:none;
  z-index:99;
  background:transparent;
}
.scroll-meter__fill{
  display:block;
  width:100%;
  height:100%;
  background:linear-gradient(180deg,var(--lava),var(--ember));
  transform-origin:top center;
  transform:scaleY(var(--p,0));
}

/* ---------- 页脚 ---------- */
.site-footer{
  position:relative;
  background:var(--ink-2);
  border-top:1px solid var(--line);
  color:var(--ash);
  font-size:14px;
  line-height:1.7;
}
.footer-ticker{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:12px;
  padding:11px var(--gutter);
  border-bottom:1px solid var(--line);
  font-family:var(--mono);
  font-size:11px;
  letter-spacing:.1em;
}
.footer-ticker__label{
  display:inline-flex;
  align-items:center;
  gap:8px;
  color:var(--lava);
}
.footer-ticker__label::before{
  content:"";
  width:6px;
  height:6px;
  border-radius:50%;
  background:var(--lava);
  box-shadow:0 0 0 3px rgba(255,90,31,.18);
}
.footer-ticker__link{
  color:var(--ash);
  text-decoration:none;
  border-bottom:1px solid var(--line);
  padding-bottom:1px;
  transition:color .2s var(--ease),border-color .2s var(--ease);
}
.footer-ticker__link:hover{
  color:var(--paper);
  border-bottom-color:var(--lava);
}

.footer-grid{
  display:grid;
  grid-template-columns:1.5fr 1fr 1.35fr 1fr;
  gap:clamp(24px,4vw,56px);
  padding:clamp(32px,5vw,56px) var(--gutter) 28px;
}
.footer-col{min-width:0}
.footer-col--brand{grid-column:1}
.footer-logo{
  margin:0 0 14px;
  font-size:26px;
  font-weight:900;
  line-height:1;
  letter-spacing:-.02em;
  color:var(--paper);
}
.footer-logo::after{
  content:"";
  display:inline-block;
  width:3px;
  height:16px;
  margin-left:10px;
  background:var(--lava);
  vertical-align:-2px;
}
.footer-note{
  margin:0;
  max-width:30ch;
  font-size:13px;
  line-height:1.72;
  color:var(--ash);
}
.footer-note--sm{
  margin-top:14px;
  max-width:34ch;
  font-size:12px;
  line-height:1.65;
  color:var(--dim);
}
.footer-title{
  margin:0 0 16px;
  font-family:var(--mono);
  font-size:11px;
  font-weight:500;
  letter-spacing:.24em;
  color:var(--dim);
}
.footer-list{
  display:flex;
  flex-direction:column;
  gap:9px;
  margin:0;
  padding:0;
  list-style:none;
}
.footer-list a{
  color:var(--paper);
  font-size:14px;
  text-decoration:none;
  border-bottom:1px solid transparent;
  transition:color .2s var(--ease),border-color .2s var(--ease);
}
.footer-list a:hover{
  color:var(--lava);
  border-bottom-color:var(--lava);
}
.footer-list--meta{gap:7px}
.footer-meta{
  font-family:var(--mono);
  font-size:12.5px;
  letter-spacing:.02em;
  color:var(--ash);
  overflow-wrap:anywhere;
}
.footer-legal{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:12px 24px;
  margin:0 var(--gutter);
  padding:16px 0 22px;
  border-top:1px solid var(--line);
  font-family:var(--mono);
  font-size:11px;
  letter-spacing:.1em;
  color:#857B72;
}
.footer-legal p{margin:0}
.footer-legal__copy{color:#857B72}
.footer-legal__icp{color:var(--dim)}
.footer-legal__links{
  display:flex;
  flex-wrap:wrap;
  gap:18px;
}
.footer-legal__links a{
  color:var(--ash);
  text-decoration:none;
  transition:color .2s var(--ease);
}
.footer-legal__links a:hover{color:var(--lava)}

/* ---------- 动效 ---------- */
.js [data-reveal]{
  opacity:0;
  transform:translateY(12px);
  transition:opacity .4s var(--ease),transform .4s var(--ease);
}
.js [data-reveal][data-revealed]{
  opacity:1;
  transform:none;
}

/* ---------- 桌面内容让位给竖排框架 ---------- */
@media (min-width:960px){
  body{padding-left:var(--rail)}
}

/* ---------- 平板 ---------- */
@media (max-width:1023px){
  .footer-grid{grid-template-columns:1fr 1fr}
  .footer-col--brand{grid-column:1 / -1}
}

/* ---------- 移动与窄屏 ---------- */
@media (max-width:959px){
  body{padding-bottom:64px}

  .site-header{
    position:sticky;
    top:0;
    left:auto;
    right:auto;
    bottom:auto;
    width:auto;
    height:auto;
    min-height:58px;
    flex-direction:row;
    align-items:center;
    justify-content:space-between;
    gap:12px;
    padding:0 var(--gutter);
    border-right:0;
    border-bottom:1px solid var(--line);
    background:var(--ink-2);
    overflow:visible;
  }

  .brand{
    flex-direction:row;
    align-items:center;
    gap:10px;
    padding:0;
  }
  .brand__mark{
    writing-mode:horizontal-tb;
    font-size:17px;
    letter-spacing:.06em;
  }
  .brand__rule{width:3px;height:16px}
  .brand__tag{display:none}

  .nav-toggle{
    display:inline-flex;
    align-items:center;
    gap:9px;
    min-height:44px;
    padding:0 12px;
    background:transparent;
    border:1px solid var(--line);
    border-radius:var(--radius);
    color:var(--paper);
    font-family:var(--sans);
    font-size:12px;
    letter-spacing:.16em;
    cursor:pointer;
  }
  .nav-toggle__label{line-height:1}
  .nav-toggle__glyph{
    position:relative;
    display:block;
    width:16px;
    height:2px;
    background:var(--paper);
    transition:background .2s var(--ease);
  }
  .nav-toggle__glyph::before,
  .nav-toggle__glyph::after{
    content:"";
    position:absolute;
    left:0;
    width:16px;
    height:2px;
    background:var(--paper);
    transition:transform .2s var(--ease);
  }
  .nav-toggle__glyph::before{top:-5px}
  .nav-toggle__glyph::after{top:5px}
  .nav-toggle[aria-expanded="true"] .nav-toggle__glyph{background:transparent}
  .nav-toggle[aria-expanded="true"] .nav-toggle__glyph::before{transform:translateY(5px) rotate(45deg)}
  .nav-toggle[aria-expanded="true"] .nav-toggle__glyph::after{transform:translateY(-5px) rotate(-45deg)}

  .site-nav{
    position:fixed;
    left:0;
    right:0;
    bottom:0;
    width:auto;
    margin:0;
    flex-direction:row;
    align-items:stretch;
    justify-content:flex-start;
    gap:0;
    max-height:78vh;
    background:var(--ink-2);
    border-top:1px solid var(--line);
    overflow-x:auto;
    overflow-y:hidden;
    scrollbar-width:none;
    z-index:96;
  }
  .site-nav::-webkit-scrollbar{display:none}

  .site-nav__list{
    flex-direction:row;
    gap:0;
    padding:0;
  }
  .site-nav__link{
    flex-direction:column;
    align-items:center;
    justify-content:center;
    gap:3px;
    min-height:56px;
    padding:8px 14px;
    border-left:0;
    border-top:2px solid transparent;
    font-size:12px;
    white-space:nowrap;
  }
  .site-nav__idx{font-size:9px}
  .site-nav__link:hover{background:rgba(255,90,31,.08)}
  .site-nav__link[aria-current="page"]{
    border-left-color:transparent;
    border-top-color:var(--lava);
    background:rgba(255,90,31,.1);
  }

  .header-actions{display:none}

  .site-nav[data-open]{
    flex-direction:column;
    padding:14px 14px 22px;
    max-height:82vh;
    border-top:2px solid var(--lava);
    border-radius:6px 6px 0 0;
    box-shadow:0 -22px 50px rgba(0,0,0,.6);
    overflow-x:hidden;
    overflow-y:auto;
  }
  .site-nav[data-open] .site-nav__list{
    flex-direction:column;
    gap:4px;
  }
  .site-nav[data-open] .site-nav__link{
    flex-direction:row;
    align-items:baseline;
    justify-content:flex-start;
    gap:10px;
    min-height:48px;
    padding:12px;
    border-top:0;
    border-left:2px solid transparent;
    font-size:14px;
  }
  .site-nav[data-open] .site-nav__link[aria-current="page"]{
    border-top-color:transparent;
    border-left-color:var(--lava);
  }
  .site-nav[data-open] .header-actions{
    display:flex;
    flex-direction:row;
    align-items:stretch;
    gap:10px;
    width:100%;
    padding:16px 0 0;
  }
  .site-nav[data-open] .header-actions .btn{
    writing-mode:horizontal-tb;
    width:auto;
    flex:1 1 0;
    min-height:48px;
    padding:12px 10px;
    font-size:13px;
    letter-spacing:.08em;
  }

  .scroll-meter{
    position:absolute;
    top:auto;
    left:0;
    right:0;
    bottom:-1px;
    width:auto;
    height:2px;
  }
  .scroll-meter__fill{
    transform-origin:left center;
    transform:scaleX(var(--p,0));
  }
}

@media (max-width:639px){
  .footer-grid{grid-template-columns:1fr;gap:28px}
  .footer-legal{
    flex-direction:column;
    align-items:flex-start;
    gap:10px;
  }
  .breadcrumb{padding-top:18px}
}

/* ---------- 无障碍：减少动效 ---------- */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
    scroll-behavior:auto !important;
  }
  .js [data-reveal]{
    opacity:1;
    transform:none;
  }
  .btn:hover{transform:none}
  .scroll-meter__fill{transition:none}
}