/* =========================================================
   8883 特色主站 · 共享外壳样式 /assets/site.css
   分区：变量 / Reset / 中文排版 / 页头 / 页脚 / 通用组件
   ========================================================= */

/* ---------- 1. 变量 ---------- */
:root{
  --paper:#F6F2E9;
  --sand:#E8DCC8;
  --mist:#CFE0DA;
  --moss:#7A8C82;
  --grass:#2F6B5E;
  --ink-deep:#123A34;
  --cinnabar:#C0392B;
  --amber:#C99A2E;
  --ink:#1C1B18;
  --clay:#8A5B3B;

  --clay-line:rgba(138,91,59,.42);
  --clay-line-soft:rgba(138,91,59,.22);
  --clay-shadow:rgba(138,91,59,.16);
  --grass-tint:rgba(47,107,94,.12);
  --cinnabar-tint:rgba(192,57,43,.08);

  --serif:"Source Han Serif SC","Noto Serif SC","Songti SC","SimSun",Georgia,serif;
  --sans:"Source Han Sans SC","Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,sans-serif;
  --mono:"IBM Plex Mono","Roboto Mono",ui-monospace,Menlo,Consolas,"Courier New",monospace;

  --frame-w:1200px;
  --ease:cubic-bezier(.22,.61,.36,1);
  --paper-on-dark:rgba(246,242,233,.78);
}

/* ---------- 2. Reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{
  -webkit-text-size-adjust:100%;
  scroll-behavior:smooth;
  scroll-padding-top:140px;
}
body{
  margin:0;
  background:var(--paper);
  color:var(--ink);
  font-family:var(--sans);
  font-size:17px;
  line-height:1.75;
  overflow-x:hidden;
}
img,svg,video{max-width:100%;display:block}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer}
a{color:var(--grass);text-decoration:none}
ul,ol{list-style:none;margin:0;padding:0}
h1,h2,h3,h4,h5,h6{margin:0;font-family:var(--serif);font-weight:800;line-height:1.24;color:var(--ink-deep)}
p{margin:0 0 1.2em}
p:last-child{margin-bottom:0}
:focus-visible{outline:2px solid var(--cinnabar);outline-offset:3px}
::selection{background:rgba(47,107,94,.2)}

/* ---------- 3. 中文排版与版面工具 ---------- */
.display{
  font-family:var(--serif);
  font-weight:900;
  font-size:clamp(2.6rem,6vw,4.5rem);
  line-height:1.08;
  letter-spacing:-.01em;
  color:var(--ink-deep);
}
.h-section{
  font-family:var(--serif);
  font-weight:800;
  font-size:clamp(1.6rem,3vw,2.4rem);
  line-height:1.25;
  letter-spacing:-.005em;
}
.prose{max-width:44em;font-size:17px;line-height:1.75}
.prose p{margin-bottom:1.2em}
.prose strong{font-weight:600;color:var(--ink-deep)}
.label{
  display:inline-block;
  font-family:var(--sans);
  font-size:12.5px;
  letter-spacing:.12em;
  color:var(--moss);
  text-transform:uppercase;
}
.num{
  font-family:var(--mono);
  font-variant-numeric:tabular-nums;
  letter-spacing:.02em;
}
.num--amber{color:var(--amber)}

.wrap{width:100%;max-width:var(--frame-w);margin:0 auto;padding:0 24px}
.section{padding:72px 0}
.section--band{
  background:var(--sand);
  border-top:1px solid var(--clay-line-soft);
  border-bottom:1px solid var(--clay-line-soft);
  padding:72px 0;
}

/* ---------- 4. 页头 ---------- */
.skip-link{
  position:absolute;
  left:16px;
  top:-80px;
  z-index:300;
  padding:10px 18px;
  background:var(--cinnabar);
  color:#fff;
  font-size:14px;
  letter-spacing:.04em;
  transition:top .2s var(--ease);
}
.skip-link:focus{top:14px;color:#fff}

.site-header{
  position:sticky;
  top:0;
  z-index:120;
}

/* 4.1 窄版期次标识带 */
.header-band{
  background:var(--sand);
  border-bottom:1px solid var(--clay-line-soft);
}
.band-inner{
  max-width:var(--frame-w);
  margin:0 auto;
  padding:7px 24px;
  display:flex;
  align-items:center;
  gap:16px;
  font-family:var(--mono);
  font-size:12px;
  letter-spacing:.06em;
  color:#5f5b50;
}
.band-tag{
  flex:0 0 auto;
  padding:1px 8px;
  color:var(--cinnabar);
  border:1px solid rgba(192,57,43,.55);
  background:var(--cinnabar-tint);
  font-size:11px;
  letter-spacing:.12em;
}
.band-text{
  flex:1 1 auto;
  min-width:0;
  overflow:hidden;
  white-space:nowrap;
  text-overflow:ellipsis;
  color:#6a6558;
}
.band-link{
  flex:0 0 auto;
  color:var(--grass);
  border-bottom:1px solid rgba(47,107,94,.35);
  padding-bottom:1px;
  transition:color .2s var(--ease),border-color .2s var(--ease);
}
.band-link:hover{color:var(--cinnabar);border-color:var(--cinnabar)}

/* 4.2 框架横梁 */
.header-frame{
  position:relative;
  background:var(--grass);
  border-bottom:3px solid var(--ink-deep);
}
.frame-inner{
  max-width:var(--frame-w);
  margin:0 auto;
  padding:13px 24px;
  display:flex;
  align-items:center;
  gap:26px;
}
.brand{
  flex:0 0 auto;
  display:flex;
  flex-direction:column;
  gap:1px;
  color:var(--paper);
}
.brand-mark{
  font-family:var(--serif);
  font-weight:800;
  font-size:23px;
  line-height:1.2;
  letter-spacing:.01em;
  color:var(--paper);
}
.brand-tagline{
  font-family:var(--mono);
  font-size:10.5px;
  letter-spacing:.11em;
  color:rgba(246,242,233,.7);
}

.nav-toggle{
  display:none;
  align-items:center;
  gap:9px;
  margin-left:auto;
  padding:8px 15px;
  border:1px solid rgba(246,242,233,.5);
  color:var(--paper);
  font-size:14px;
  letter-spacing:.08em;
  transition:border-color .2s var(--ease),background-color .2s var(--ease);
}
.nav-toggle::after{
  content:"";
  width:7px;
  height:7px;
  background:var(--paper);
  transition:background-color .2s var(--ease);
}
.nav-toggle:hover{border-color:var(--paper);background:rgba(18,58,52,.35)}
.nav-toggle[aria-expanded="true"]{border-color:var(--paper);background:rgba(18,58,52,.5)}
.nav-toggle[aria-expanded="true"]::after{background:var(--cinnabar)}

.site-nav{margin-left:auto;min-width:0}
.nav-list{
  display:flex;
  align-items:center;
  gap:4px;
  flex-wrap:nowrap;
}
.nav-link{
  display:flex;
  align-items:center;
  gap:7px;
  padding:7px 10px;
  border:1px solid transparent;
  color:rgba(246,242,233,.84);
  font-size:14.5px;
  line-height:1.4;
  white-space:nowrap;
  transition:color .2s var(--ease),border-color .2s var(--ease),background-color .2s var(--ease);
}
.nav-link::before{
  content:"";
  flex:0 0 auto;
  width:7px;
  height:7px;
  background:rgba(246,242,233,.4);
  transition:background-color .2s var(--ease);
}
.nav-index{
  font-family:var(--mono);
  font-size:10.5px;
  letter-spacing:.06em;
  color:var(--amber);
}
.nav-link:hover{
  color:#fff;
  border-color:rgba(246,242,233,.65);
  background:rgba(18,58,52,.28);
}
.nav-link:hover::before{background:var(--amber)}
.nav-link[aria-current="page"]{
  color:#fff;
  background:rgba(18,58,52,.6);
  border-color:rgba(246,242,233,.5);
  font-weight:600;
}
.nav-link[aria-current="page"]::before{background:var(--cinnabar)}
.nav-link--cta{
  margin-left:10px;
  padding:8px 15px;
  background:var(--cinnabar);
  border-color:rgba(255,255,255,.3);
  color:#fff;
}
.nav-link--cta::before{display:none}
.nav-link--cta:hover{
  background:#a92f22;
  border-color:rgba(255,255,255,.8);
  color:#fff;
}

/* ---------- 5. 页脚 ---------- */
.site-footer{
  position:relative;
  margin-top:96px;
  background:var(--ink-deep);
  color:var(--paper);
}
.footer-ruler{
  height:26px;
  background-image:repeating-linear-gradient(90deg,rgba(246,242,233,.32) 0 1px,transparent 1px 24px);
  border-bottom:1px solid rgba(246,242,233,.16);
}
.footer-inner{
  max-width:var(--frame-w);
  margin:0 auto;
  padding:56px 24px 44px;
  display:grid;
  grid-template-columns:minmax(0,1.05fr) minmax(0,1.5fr);
  gap:56px;
}
.footer-brand{min-width:0}
.footer-mark{
  margin:0 0 6px;
  font-family:var(--serif);
  font-weight:800;
  font-size:30px;
  line-height:1.2;
  color:var(--paper);
}
.footer-tagline{
  margin:0 0 18px;
  font-family:var(--mono);
  font-size:11px;
  letter-spacing:.12em;
  color:rgba(246,242,233,.62);
}
.footer-summary{
  margin:0 0 24px;
  max-width:32em;
  font-size:15px;
  line-height:1.75;
  color:rgba(246,242,233,.78);
}
.footer-cols{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  gap:32px;
}
.footer-col{min-width:0}
.footer-col-title{
  margin:0 0 14px;
  padding-bottom:10px;
  border-bottom:1px solid rgba(246,242,233,.18);
  font-family:var(--mono);
  font-size:12px;
  font-weight:400;
  letter-spacing:.14em;
  color:var(--amber);
}
.footer-links{display:flex;flex-direction:column;gap:2px}
.footer-link{
  display:inline-flex;
  align-items:center;
  gap:9px;
  padding:5px 0;
  font-size:15px;
  color:rgba(246,242,233,.82);
  border-bottom:1px solid transparent;
  transition:color .2s var(--ease),border-color .2s var(--ease);
}
.footer-link::before{
  content:"";
  flex:0 0 auto;
  width:6px;
  height:6px;
  background:var(--moss);
  transition:background-color .2s var(--ease);
}
.footer-link:hover{color:var(--paper);border-bottom-color:var(--amber)}
.footer-link:hover::before{background:var(--amber)}

.footer-meta{
  background:rgba(0,0,0,.18);
  border-top:1px solid rgba(246,242,233,.16);
}
.footer-meta-inner{
  max-width:var(--frame-w);
  margin:0 auto;
  padding:22px 24px;
  display:flex;
  flex-wrap:wrap;
  gap:6px 34px;
  align-items:baseline;
}
.meta-line{
  margin:0;
  font-size:13.5px;
  line-height:1.7;
  color:rgba(246,242,233,.68);
}
.meta-line--icp{
  margin-left:auto;
  font-family:var(--mono);
  font-size:12.5px;
  letter-spacing:.04em;
  color:rgba(246,242,233,.6);
}

/* ---------- 6. 通用组件 ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  gap:9px;
  padding:11px 20px;
  border:1px solid var(--moss);
  background:transparent;
  color:var(--grass);
  font-family:var(--sans);
  font-size:15px;
  line-height:1.4;
  cursor:pointer;
  transition:background-color .2s var(--ease),color .2s var(--ease),border-color .2s var(--ease);
}
.btn:hover{
  border-color:var(--grass);
  background:var(--grass-tint);
  color:var(--ink-deep);
}
.btn--solid{
  background:var(--grass);
  border-color:var(--grass);
  color:var(--paper);
}
.btn--solid:hover{
  background:var(--ink-deep);
  border-color:var(--ink-deep);
  color:var(--paper);
}
.btn--cinnabar{
  background:var(--cinnabar);
  border-color:var(--cinnabar);
  color:#fff;
}
.btn--cinnabar:hover{
  background:#a92f22;
  border-color:#a92f22;
  color:#fff;
}
.btn--ghost{
  border-color:rgba(246,242,233,.55);
  color:var(--paper);
}
.btn--ghost:hover{
  border-color:var(--paper);
  background:rgba(246,242,233,.12);
  color:var(--paper);
}

.chip{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:3px 9px;
  border:1px solid var(--clay-line);
  background:rgba(246,242,233,.6);
  color:var(--clay);
  font-family:var(--mono);
  font-size:12px;
  letter-spacing:.1em;
  line-height:1.6;
}
.chip--grass{
  border-color:rgba(47,107,94,.4);
  background:var(--grass-tint);
  color:var(--grass);
}
.chip--cinnabar{
  border-color:rgba(192,57,43,.45);
  background:var(--cinnabar-tint);
  color:var(--cinnabar);
}

.breadcrumb{
  max-width:var(--frame-w);
  margin:0 auto;
  padding:22px 24px 0;
}
.breadcrumb ol{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:0 9px;
  font-family:var(--mono);
  font-size:12px;
  letter-spacing:.05em;
  color:var(--moss);
}
.breadcrumb li{display:flex;align-items:center;gap:9px}
.breadcrumb li+li::before{content:"/";color:rgba(122,140,130,.7)}
.breadcrumb a{
  color:var(--grass);
  border-bottom:1px solid transparent;
  transition:color .2s var(--ease),border-color .2s var(--ease);
}
.breadcrumb a:hover{color:var(--cinnabar);border-bottom-color:var(--cinnabar)}

/* 画板 */
.panel{
  position:relative;
  padding:32px;
  background:var(--paper);
  border:1px solid var(--clay-line);
  box-shadow:6px 6px 0 var(--clay-shadow);
}
.panel--sand{background:var(--sand)}
.panel--mist{background:var(--mist)}
.panel--deep{
  background:var(--ink-deep);
  border-color:rgba(18,58,52,.7);
  color:var(--paper);
  box-shadow:6px 6px 0 rgba(18,58,52,.28);
}
.panel--deep h1,.panel--deep h2,.panel--deep h3{color:var(--paper)}
.panel--tilt-l{transform:rotate(-.4deg)}
.panel--tilt-r{transform:rotate(.5deg)}

/* 图片容器基础规则 */
.media-frame{
  position:relative;
  overflow:hidden;
  background:var(--sand);
  border:1px solid var(--clay-line);
  box-shadow:6px 6px 0 var(--clay-shadow);
}
.media-frame__img{
  width:100%;
  height:100%;
  object-fit:cover;
}
.media-frame__placeholder{
  position:absolute;
  inset:0;
  display:flex;
  align-items:flex-end;
  padding:14px 16px;
  font-family:var(--mono);
  font-size:11.5px;
  letter-spacing:.12em;
  color:rgba(28,27,24,.5);
}
.media-frame__caption{
  display:block;
  margin-top:10px;
  font-size:13px;
  line-height:1.7;
  color:var(--moss);
}
.media-frame--map{
  aspect-ratio:4/3;
  background:
    radial-gradient(circle at 28% 34%,rgba(47,107,94,.22),transparent 46%),
    radial-gradient(circle at 72% 62%,rgba(201,154,46,.16),transparent 42%),
    var(--sand);
}
.media-frame--map::after{
  content:"";
  position:absolute;
  inset:0;
  pointer-events:none;
  background-image:
    repeating-linear-gradient(0deg,rgba(47,107,94,.14) 0 1px,transparent 1px 30px),
    repeating-linear-gradient(90deg,rgba(47,107,94,.14) 0 1px,transparent 1px 30px);
}
.media-frame--step{
  aspect-ratio:16/9;
  background:linear-gradient(180deg,rgba(207,224,218,.6),rgba(232,220,200,.85));
}
.media-frame--micro{
  aspect-ratio:1/1;
  background:
    radial-gradient(circle at 50% 46%,rgba(138,91,59,.28),transparent 58%),
    var(--sand);
}

/* ---------- 7. 状态与动效协议 ---------- */
[data-reveal]{
  opacity:0;
  transform:translateY(12px);
  transition:opacity .42s var(--ease),transform .42s var(--ease);
}
[data-reveal].is-visible{opacity:1;transform:none}

[data-step-item]{
  color:var(--moss);
  transition:color .24s var(--ease);
}
[data-step-item].is-current{color:var(--cinnabar)}

.back-to-top{
  position:fixed;
  right:20px;
  bottom:20px;
  z-index:150;
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:10px 15px;
  background:var(--paper);
  border:1px solid var(--clay-line);
  box-shadow:4px 4px 0 var(--clay-shadow);
  color:var(--ink-deep);
  font-family:var(--mono);
  font-size:12px;
  letter-spacing:.08em;
  opacity:0;
  visibility:hidden;
  transition:opacity .24s var(--ease),visibility .24s var(--ease),border-color .2s var(--ease),color .2s var(--ease);
}
.back-to-top[data-visible]{opacity:1;visibility:visible}
.back-to-top:hover{border-color:var(--grass);color:var(--grass)}

/* ---------- 8. 响应式 ---------- */
@media (max-width:1080px){
  .nav-toggle{display:inline-flex}
  .site-nav{
    position:absolute;
    top:100%;
    left:0;
    right:0;
    margin-left:0;
    display:none;
    background:var(--ink-deep);
    border-top:1px solid rgba(246,242,233,.18);
    border-bottom:3px solid var(--cinnabar);
    max-height:calc(100vh - 120px);
    overflow-y:auto;
  }
  .site-nav[data-open]{display:block}
  .nav-list{
    flex-direction:column;
    align-items:stretch;
    gap:0;
    padding:8px 0 14px;
  }
  .nav-link{
    padding:13px 24px;
    border:0;
    border-left:3px solid transparent;
    font-size:16px;
  }
  .nav-link::before{width:8px;height:8px}
  .nav-link:hover,.nav-link[aria-current="page"]{
    background:rgba(246,242,233,.08);
    border-color:transparent;
    border-left-color:var(--cinnabar);
  }
  .nav-link[aria-current="page"]::before{background:var(--cinnabar)}
  .nav-link--cta{
    margin:12px 24px 0;
    justify-content:center;
    border-left:0;
  }
  .nav-link--cta:hover{border-left-color:transparent}
  html{scroll-padding-top:110px}
}

@media (max-width:900px){
  .footer-inner{
    grid-template-columns:minmax(0,1fr);
    gap:40px;
    padding:48px 24px 36px;
  }
  .footer-cols{grid-template-columns:repeat(3,minmax(0,1fr));gap:24px}
}

@media (max-width:640px){
  body{font-size:16.5px}
  .wrap{padding:0 20px}
  .section{padding:56px 0}
  .section--band{padding:56px 0}
  .band-inner{padding:6px 20px;gap:12px}
  .band-text{display:none}
  .band-link{margin-left:auto}
  .frame-inner{padding:11px 20px;gap:16px}
  .brand-mark{font-size:20px}
  .brand-tagline{display:none}
  .panel{padding:22px}
  .panel--tilt-l,.panel--tilt-r{transform:none}
  .breadcrumb{padding:18px 20px 0}
  .footer-cols{grid-template-columns:minmax(0,1fr);gap:28px}
  .footer-mark{font-size:25px}
  .footer-meta-inner{padding:20px;flex-direction:column;gap:8px}
  .meta-line--icp{margin-left:0}
  .back-to-top{right:14px;bottom:14px}
  .site-footer{margin-top:64px}
}

/* ---------- 9. 可访问性兜底 ---------- */
@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;
  }
  [data-reveal]{opacity:1;transform:none}
}