/* ============================================================
   356手机版中心 · /assets/site.css
   共享层：变量 / 重置 / 中文排版 / 页头 / 页脚 / 通用组件
   页面专属布局写在各自的 page css 中
   ============================================================ */

/* ---------- 01 设计变量 ---------- */
:root{
  --ink-900:#0A0F1E;
  --ink-800:#131A2C;
  --line:#232C44;
  --amber:#E9A63C;
  --amber-soft:#F7D391;
  --teal:#2FB6A1;
  --teal-soft:#8ADCCE;
  --paper:#F2EAD9;
  --text:#E6EAF3;
  --muted:#9AA5BC;
  --seal:#D2725A;

  --rail:72px;
  --topline:48px;
  --bar-mobile:64px;

  --font-body:"PingFang SC","Hiragino Sans GB","Noto Sans SC","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-display:"PingFang SC","Hiragino Sans GB","Noto Sans SC","Microsoft YaHei",system-ui,sans-serif;
  --font-num:"DIN Alternate","Barlow","Roboto Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;

  --ease:cubic-bezier(.2,.7,.3,1);
  --dur:.24s;
  --r-sm:3px;
  --r-md:6px;
}

/* ---------- 02 重置 ---------- */
*,*::before,*::after{box-sizing:border-box;}
html{
  -webkit-text-size-adjust:100%;
  scroll-behavior:smooth;
  scroll-padding-top:calc(var(--topline) + 20px);
}
body{
  margin:0;
  min-height:100vh;
  padding:var(--topline) 0 0 var(--rail);
  background-color:var(--ink-900);
  background-image:
    radial-gradient(880px 520px at 82% -8%, rgba(233,166,60,.10), transparent 62%),
    radial-gradient(720px 500px at 4% 10%, rgba(47,182,161,.08), transparent 62%),
    radial-gradient(rgba(230,234,243,.05) 1px, transparent 1px);
  background-size:auto,auto,4px 4px;
  background-repeat:no-repeat,no-repeat,repeat;
  background-attachment:fixed,fixed,fixed;
  color:var(--text);
  font-family:var(--font-body);
  font-size:16px;
  font-weight:400;
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
img,svg,video{display:block;max-width:100%;}
a{color:inherit;text-decoration:none;}
button{font:inherit;color:inherit;background:none;border:0;padding:0;cursor:pointer;}
ul,ol{margin:0;padding:0;list-style:none;}
figure{margin:0;}
[hidden]{display:none !important;}

p{margin:0 0 1.2em;}
h1,h2,h3,h4{
  margin:0 0 .5em;
  font-family:var(--font-display);
  font-weight:800;
  line-height:1.25;
  letter-spacing:-.02em;
  color:#fff;
}
h1{font-size:clamp(32px,5vw,56px);font-weight:900;}
h2{font-size:clamp(24px,3.4vw,36px);}
h3{font-size:clamp(19px,2.2vw,24px);}
strong,b{font-weight:700;color:#fff;}
::selection{background:rgba(233,166,60,.34);color:#fff;}
:focus-visible{outline:2px solid var(--amber);outline-offset:3px;border-radius:2px;}

/* ---------- 03 跳至主内容 ---------- */
.skip-link{
  position:fixed;
  top:8px;left:8px;
  z-index:200;
  padding:10px 16px;
  background:var(--amber);
  color:#1a1204;
  font-size:14px;
  font-weight:700;
  border-radius:var(--r-sm);
  transform:translateY(-180%);
  transition:transform var(--dur) var(--ease);
}
.skip-link:focus{transform:none;}

/* ---------- 04 页头：细框 + 书签轨道 ---------- */
.site-header{position:fixed;inset:0;z-index:100;pointer-events:none;}
.site-header > *{pointer-events:auto;}

/* 4.1 顶部细框 */
.topline{
  position:absolute;
  top:0;left:0;right:0;
  height:var(--topline);
  display:flex;
  align-items:center;
  gap:18px;
  padding:0 20px;
  background:rgba(10,15,30,.94);
  border-bottom:1px solid var(--line);
  backdrop-filter:blur(8px);
  -webkit-backdrop-filter:blur(8px);
}
.topline__brand{
  margin:0;
  font-family:var(--font-display);
  font-weight:900;
  font-size:15px;
  letter-spacing:.02em;
  color:#fff;
  white-space:nowrap;
}
.topline__sign{
  margin:0;
  font-size:12px;
  letter-spacing:.26em;
  color:var(--muted);
  white-space:nowrap;
}
.topline__where{
  margin:0 0 0 auto;
  display:flex;
  align-items:baseline;
  gap:8px;
  white-space:nowrap;
}
.topline__where-label{
  font-size:11.5px;
  letter-spacing:.24em;
  color:rgba(154,165,188,.75);
}
.topline__where-value{
  font-family:var(--font-num);
  font-size:14px;
  letter-spacing:.06em;
  color:var(--amber);
  transition:color var(--dur) var(--ease);
}
.readbar{
  position:absolute;
  left:0;right:0;bottom:-1px;
  height:3px;
  background:rgba(35,44,68,.85);
  overflow:hidden;
}
.readbar__fill{
  display:block;
  height:100%;
  width:0;
  background:linear-gradient(90deg,var(--teal),var(--amber));
  transition:width .12s linear;
}
@keyframes amber-pulse{
  0%{box-shadow:0 0 0 rgba(233,166,60,0);}
  40%{box-shadow:0 0 16px rgba(233,166,60,.9);}
  100%{box-shadow:0 0 0 rgba(233,166,60,0);}
}
.readbar.is-flash .readbar__fill{animation:amber-pulse .46s var(--ease);}

/* 4.2 左侧书签轨道 */
.rail{
  position:absolute;
  top:var(--topline);
  left:0;
  bottom:0;
  width:var(--rail);
  display:flex;
  flex-direction:column;
  align-items:stretch;
  gap:10px;
  padding:10px 8px 14px;
  background:linear-gradient(180deg,rgba(19,26,44,.94),rgba(10,15,30,.94));
  border-right:1px solid var(--line);
  overflow-y:auto;
  overscroll-behavior:contain;
  scrollbar-width:none;
}
.rail::-webkit-scrollbar{width:0;height:0;}

.rail__toggle{
  display:none;
  align-items:center;
  gap:10px;
  padding:11px 14px;
  background:var(--ink-800);
  border:1px solid var(--line);
  border-radius:var(--r-sm);
  font-size:14px;
  font-weight:500;
  letter-spacing:.06em;
  transition:background-color var(--dur) var(--ease),color var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.rail__bars{display:flex;flex-direction:column;gap:3px;width:16px;}
.rail__bars i{display:block;height:2px;background:var(--amber);border-radius:1px;}
.rail__bars i:nth-child(2){width:70%;background:var(--teal);}
.rail__bars i:nth-child(3){width:45%;}

.rail__list{display:flex;flex-direction:column;gap:6px;}

.rail__link{
  display:flex;
  align-items:center;
  justify-content:center;
  writing-mode:vertical-rl;
  padding:14px 0;
  width:100%;
  background:linear-gradient(180deg,rgba(19,26,44,.86),rgba(10,15,30,.86));
  border:1px solid var(--line);
  border-left:0;
  border-radius:0 var(--r-md) var(--r-md) 0;
  color:var(--muted);
  font-size:13px;
  font-weight:500;
  letter-spacing:.18em;
  text-align:center;
  position:relative;
  transition:color var(--dur) var(--ease),background-color var(--dur) var(--ease),border-color var(--dur) var(--ease),transform var(--dur) var(--ease);
}
.rail__link::after{
  content:"";
  position:absolute;
  right:-1px;
  top:50%;
  width:2px;
  height:0;
  transform:translateY(-50%);
  background:var(--amber);
  transition:height var(--dur) var(--ease);
}
.rail__link:hover{
  color:var(--amber-soft);
  border-color:rgba(233,166,60,.5);
  transform:translateX(2px);
}
.rail__link:hover::after{height:34%;}
.rail__link[aria-current="page"]{
  color:#1a1204;
  background:var(--amber);
  border-color:var(--amber);
  font-weight:700;
  transform:translateX(3px);
}
.rail__link[aria-current="page"]::after{height:60%;background:var(--amber-soft);}

.rail__cta{
  margin-top:auto;
  display:flex;
  align-items:center;
  justify-content:center;
  writing-mode:vertical-rl;
  padding:18px 0;
  border:1px solid rgba(233,166,60,.45);
  border-radius:0 var(--r-md) var(--r-md) 0;
  background:rgba(233,166,60,.10);
  color:var(--amber-soft);
  font-size:12.5px;
  font-weight:700;
  letter-spacing:.2em;
  text-align:center;
  transition:background-color var(--dur) var(--ease),color var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.rail__cta:hover{background:var(--amber);color:#1a1204;border-color:var(--amber);}

/* ---------- 05 页脚 ---------- */
.site-footer{
  position:relative;
  margin-top:clamp(52px,7vw,104px);
  padding:clamp(36px,5vw,62px) 0 clamp(20px,3vw,30px);
  background:linear-gradient(180deg,rgba(19,26,44,.72),rgba(10,15,30,.97));
  border-top:1px solid var(--line);
}
.site-footer::before{
  content:"";
  position:absolute;
  top:-1px;left:0;
  width:132px;height:3px;
  background:linear-gradient(90deg,var(--amber),var(--teal));
}
.footer-frame{
  display:grid;
  grid-template-columns:minmax(200px,.9fr) 2.1fr;
  gap:clamp(24px,4vw,56px);
}
.footer-brand__mark{
  margin:0 0 6px;
  font-family:var(--font-display);
  font-weight:900;
  font-size:22px;
  letter-spacing:-.01em;
  color:#fff;
}
.footer-brand__sign{
  margin:0 0 14px;
  font-size:12.5px;
  letter-spacing:.28em;
  color:var(--amber);
}
.footer-brand__note{
  margin:0;
  max-width:28ch;
  font-size:14px;
  line-height:1.85;
  color:var(--muted);
}
.footer-cols{
  display:grid;
  grid-template-columns:repeat(4,minmax(0,1fr));
  gap:clamp(18px,2.4vw,30px);
}
.footer-col__head{
  margin:0 0 12px;
  font-size:13px;
  font-weight:700;
  letter-spacing:.2em;
  color:var(--amber-soft);
}
.footer-col__list li + li{margin-top:8px;}
.footer-col__link{
  font-size:14.5px;
  color:var(--text);
  border-bottom:1px solid transparent;
  transition:color var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.footer-col__link:hover{color:var(--amber);border-bottom-color:var(--amber);}
.footer-col__text{
  font-size:13.5px;
  line-height:1.75;
  color:var(--muted);
  word-break:break-word;
}
.footer-bottom{
  margin-top:clamp(28px,4vw,48px);
  padding-top:18px;
  border-top:1px solid var(--line);
  display:flex;
  flex-wrap:wrap;
  align-items:flex-end;
  justify-content:space-between;
  gap:12px 28px;
}
.footer-note{
  margin:0;
  max-width:62ch;
  font-size:12.5px;
  line-height:1.8;
  color:var(--muted);
}
.footer-legal{
  margin:0;
  display:flex;
  flex-wrap:wrap;
  gap:6px 18px;
  font-size:12.5px;
  color:var(--muted);
}
.footer-legal__icp{font-family:var(--font-num);letter-spacing:.04em;}
.footer-legal__year{font-family:var(--font-num);}

/* ---------- 06 布局容器与网格 ---------- */
.shell{
  width:100%;
  max-width:1180px;
  margin-inline:auto;
  padding-inline:clamp(18px,4vw,42px);
}
.shell--narrow{max-width:820px;}
.rule{height:1px;background:var(--line);border:0;margin:0;}
.grid{display:grid;gap:clamp(16px,2.2vw,26px);}
.grid--2{grid-template-columns:repeat(auto-fit,minmax(280px,1fr));}
.grid--3{grid-template-columns:repeat(auto-fit,minmax(240px,1fr));}

/* ---------- 07 章节结构 ---------- */
.sec{
  position:relative;
  padding-block:clamp(40px,6vw,84px);
}
.sec + .sec{border-top:1px solid var(--line);}
.sec-head{
  display:flex;
  flex-wrap:wrap;
  align-items:baseline;
  gap:10px 18px;
  margin-bottom:clamp(18px,2.6vw,30px);
}
.sec-head__idx{
  font-family:var(--font-num);
  font-size:clamp(26px,3.6vw,40px);
  line-height:1;
  letter-spacing:.02em;
  color:var(--muted);
  transition:color .26s var(--ease),transform .26s var(--ease);
}
.sec-head__title{
  margin:0;
  font-size:clamp(24px,3.4vw,36px);
  font-weight:900;
}
.sec-head__meta{
  margin:0 0 0 auto;
  font-size:12.5px;
  letter-spacing:.18em;
  color:var(--muted);
}
[data-section].is-current .sec-head__idx{
  color:var(--amber);
  transform:translateY(-2px);
}
.sec-lead{
  max-width:60ch;
  font-size:18px;
  line-height:1.8;
  color:var(--muted);
}

/* ---------- 08 卡片与标签 ---------- */
.card{
  position:relative;
  padding:clamp(20px,2.4vw,26px);
  background:var(--ink-800);
  border:1px solid var(--line);
  border-radius:var(--r-sm);
  box-shadow:0 14px 28px -24px rgba(0,0,0,.95);
  transition:transform var(--dur) var(--ease),box-shadow var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.card:hover{
  transform:translateY(-4px);
  border-color:rgba(233,166,60,.45);
  box-shadow:0 22px 40px -26px rgba(0,0,0,1);
}
.card__title{
  margin:0 0 8px;
  font-size:19px;
  font-weight:700;
}
.card__text{
  margin:0;
  font-size:15px;
  color:var(--muted);
}
.card--paper{
  background:var(--paper);
  color:#241c12;
  border-color:rgba(10,15,30,.18);
  box-shadow:
    0 6px 0 -2px rgba(242,234,217,.20),
    0 12px 0 -6px rgba(242,234,217,.10),
    0 18px 34px -26px rgba(0,0,0,1);
}
.card--paper .card__title,
.card--paper h3{color:#1b1409;}
.card--paper .card__text,
.card--paper p{color:#4a3f2e;}
.card--paper:hover{border-color:rgba(233,166,60,.7);}
.card--quiet{
  background:rgba(19,26,44,.5);
  box-shadow:none;
}
.card--quiet:hover{transform:none;}

.tag{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:4px 12px;
  background:var(--paper);
  color:#241c12;
  font-size:12px;
  font-weight:700;
  letter-spacing:.14em;
  clip-path:polygon(0 0,100% 0,100% 100%,10px 100%,0 calc(100% - 10px));
}
.tag--teal{background:rgba(47,182,161,.18);color:var(--teal-soft);box-shadow:inset 0 0 0 1px rgba(47,182,161,.5);}
.tag--seal{background:rgba(210,114,90,.18);color:#F0B9A8;box-shadow:inset 0 0 0 1px rgba(210,114,90,.55);}

/* ---------- 09 数字与旁注 ---------- */
.num{
  font-family:var(--font-num);
  font-variant-numeric:tabular-nums;
  letter-spacing:.02em;
  color:var(--amber);
}
.vnote{
  writing-mode:vertical-rl;
  font-size:12px;
  letter-spacing:.32em;
  color:var(--muted);
  user-select:none;
}
.muted{color:var(--muted);}
.txt-amber{color:var(--amber);}
.txt-teal{color:var(--teal-soft);}

/* ---------- 10 框景与图像容器 ---------- */
.frame{
  position:relative;
  padding:clamp(20px,3.4vw,40px);
  border:1px solid var(--line);
}
.frame::before{
  content:"";
  position:absolute;
  inset:6px;
  border:1px solid rgba(35,44,68,.9);
  pointer-events:none;
}
.frame::after{
  content:"";
  position:absolute;
  inset:0;
  pointer-events:none;
  background-image:
    linear-gradient(var(--amber),var(--amber)),
    linear-gradient(var(--amber),var(--amber)),
    linear-gradient(var(--amber),var(--amber)),
    linear-gradient(var(--amber),var(--amber)),
    linear-gradient(var(--amber),var(--amber)),
    linear-gradient(var(--amber),var(--amber)),
    linear-gradient(var(--amber),var(--amber)),
    linear-gradient(var(--amber),var(--amber));
  background-size:14px 2px,2px 14px,14px 2px,2px 14px,14px 2px,2px 14px,14px 2px,2px 14px;
  background-position:
    10px 10px,10px 10px,
    calc(100% - 10px) 10px,calc(100% - 10px) 10px,
    10px calc(100% - 10px),10px calc(100% - 10px),
    calc(100% - 10px) calc(100% - 10px),calc(100% - 10px) calc(100% - 10px);
  background-repeat:no-repeat;
  opacity:.75;
}

.media-frame{
  position:relative;
  display:block;
  overflow:hidden;
  background:var(--ink-800);
  border:1px solid var(--line);
  border-radius:var(--r-sm);
}
.media-frame::after{
  content:"";
  position:absolute;
  inset:0;
  pointer-events:none;
  background-image:radial-gradient(rgba(230,234,243,.10) 1px,transparent 1px);
  background-size:3px 3px;
  opacity:.45;
  mix-blend-mode:overlay;
}
.media-frame > img{
  width:100%;
  height:100%;
  object-fit:cover;
}
.media-frame__ph{
  position:absolute;
  inset:0;
  background:linear-gradient(140deg,rgba(47,182,161,.18),rgba(233,166,60,.14) 52%,rgba(19,26,44,.92));
}
.media-frame--wide{aspect-ratio:16/9;}
.media-frame--tall{aspect-ratio:3/4;}
.media-frame--square{aspect-ratio:1/1;}
.media-frame--band{aspect-ratio:21/9;}
.media-frame__cap{
  margin-top:10px;
  font-size:12.5px;
  letter-spacing:.06em;
  color:var(--muted);
}

/* ---------- 11 按钮 ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:12px 22px;
  background:var(--ink-800);
  border:1px solid var(--line);
  border-radius:var(--r-sm);
  color:var(--text);
  font-size:15px;
  font-weight:500;
  letter-spacing:.02em;
  transition:transform var(--dur) var(--ease),background-color var(--dur) var(--ease),color var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.btn:hover{transform:translateY(-2px);border-color:var(--amber);color:var(--amber-soft);}
.btn--amber{
  background:var(--amber);
  border-color:var(--amber);
  color:#1a1204;
  font-weight:700;
}
.btn--amber:hover{background:var(--amber-soft);border-color:var(--amber-soft);color:#1a1204;}
.btn--teal{
  background:rgba(47,182,161,.14);
  border-color:rgba(47,182,161,.55);
  color:var(--teal-soft);
}
.btn--teal:hover{background:rgba(47,182,161,.24);border-color:var(--teal);color:#D6F5EF;}
.btn--ghost{background:transparent;color:var(--muted);}
.btn--ghost:hover{color:var(--text);border-color:var(--line);}
.btn--block{width:100%;justify-content:center;}

/* ---------- 12 面包屑 ---------- */
.crumb{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:8px;
  margin-bottom:18px;
  font-size:12.5px;
  letter-spacing:.06em;
  color:var(--muted);
}
.crumb a{
  color:var(--muted);
  border-bottom:1px solid transparent;
  transition:color var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.crumb a:hover{color:var(--amber);border-bottom-color:var(--amber);}
.crumb__sep{color:rgba(35,44,68,.95);}

/* ---------- 13 折叠条目 ---------- */
.disclosure{border-top:1px solid var(--line);}
.disclosure:last-child{border-bottom:1px solid var(--line);}
.disclosure__btn{
  width:100%;
  display:flex;
  align-items:flex-start;
  justify-content:space-between;
  gap:16px;
  padding:18px 0;
  text-align:left;
  font-size:17px;
  font-weight:500;
  color:var(--text);
  transition:color var(--dur) var(--ease);
}
.disclosure__btn::after{
  content:"+";
  flex:0 0 auto;
  font-family:var(--font-num);
  font-size:18px;
  line-height:1.2;
  color:var(--amber);
}
.disclosure__btn[aria-expanded="true"]::after{content:"–";}
.disclosure__btn:hover{color:var(--amber-soft);}
.disclosure__panel{
  padding:0 0 20px;
  font-size:15px;
  color:var(--muted);
}
.disclosure__panel p:last-child{margin-bottom:0;}

/* ---------- 14 显现动效 ---------- */
.js-ready [data-reveal]{
  opacity:0;
  transform:translateY(10px);
  transition:opacity .32s var(--ease),transform .32s var(--ease);
}
.js-ready [data-reveal].is-in{opacity:1;transform:none;}

/* ---------- 15 响应式 ---------- */
@media (max-width:1080px){
  .footer-frame{grid-template-columns:1fr;}
  .footer-brand__note{max-width:52ch;}
}
@media (max-width:1024px){
  body{
    padding:var(--topline) 0 var(--bar-mobile) 0;
  }
  .rail{
    top:auto;
    bottom:0;
    left:0;
    right:0;
    width:auto;
    height:var(--bar-mobile);
    flex-direction:row;
    align-items:center;
    gap:10px;
    padding:0 14px;
    border-right:0;
    border-top:1px solid var(--line);
    overflow:visible;
    box-shadow:0 -14px 30px -24px rgba(0,0,0,1);
  }
  .rail__toggle{display:flex;}
  .rail[data-open] .rail__toggle{background:var(--amber);border-color:var(--amber);color:#1a1204;}
  .rail[data-open] .rail__toggle .rail__bars i{background:#1a1204;}
  .rail__list{
    position:absolute;
    left:0;
    right:0;
    bottom:var(--bar-mobile);
    display:none;
    flex-direction:column;
    gap:0;
    padding:8px;
    max-height:62vh;
    overflow-y:auto;
    background:var(--ink-800);
    border-top:1px solid var(--line);
    box-shadow:0 -20px 40px -28px rgba(0,0,0,1);
  }
  .rail[data-open] .rail__list{display:flex;}
  .rail__link{
    writing-mode:horizontal-tb;
    justify-content:flex-start;
    padding:14px 16px;
    border:1px solid transparent;
    border-left:2px solid transparent;
    border-radius:var(--r-sm);
    letter-spacing:.1em;
    font-size:15px;
    text-align:left;
  }
  .rail__link::after{display:none;}
  .rail__link:hover{transform:none;}
  .rail__link[aria-current="page"]{
    transform:none;
    border-left-color:#1a1204;
  }
  .rail__cta{
    margin-top:0;
    margin-left:auto;
    writing-mode:horizontal-tb;
    padding:11px 16px;
    border-radius:var(--r-sm);
    font-size:13px;
  }
}
@media (max-width:900px){
  .footer-cols{grid-template-columns:repeat(2,minmax(0,1fr));}
}
@media (max-width:640px){
  .topline{gap:12px;padding:0 14px;}
  .topline__sign{display:none;}
  .topline__where-label{display:none;}
  .sec-head__meta{margin-left:0;width:100%;}
  .footer-cols{grid-template-columns:1fr;}
  .footer-bottom{align-items:flex-start;}
  .sec-lead{font-size:17px;}
  .btn{width:100%;justify-content:center;}
  .btn--inline{width:auto;}
}

/* ---------- 16 尊重减弱动效 ---------- */
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto;}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  .js-ready [data-reveal]{opacity:1;transform:none;}
  .card:hover{transform:none;}
  .btn:hover{transform:none;}
}