/* ==========================================================================
   全讯主站 · 共享样式表 /assets/site.css
   1 变量  2 重置  3 基础排版  4 布局原子  5 信息组件
   6 页头  7 页脚  8 响应式  9 可访问性
   ========================================================================== */

/* 1 变量 ---------------------------------------------------------------- */
:root{
  --paper:#F4EFE4;
  --indigo:#1B2A4A;
  --ink-deep:#0F1B33;
  --amber:#C8912F;
  --amber-light:#E8C77A;
  --celadon:#4E8C7A;
  --coral:#D9584A;
  --gray-brown:#6B6255;
  --rule:#DAD2C4;
  --glass:#2C3E63;

  --page-x:clamp(20px,5vw,96px);
  --gutter:24px;
  --maxw:1320px;

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

  --step-hero:clamp(2rem,6vw,5.5rem);
  --step-title:clamp(1.4rem,2.6vw,2.2rem);
  --step-body:1rem;
  --step-meta:0.8125rem;

  --radius:4px;
  --shadow-plate:0 12px 32px rgba(27,42,74,.08);
  --shadow-line:0 1px 0 var(--rule);
  --ease:cubic-bezier(.2,.7,.3,1);
  --dur-fast:160ms;
  --dur-mid:180ms;
  --dur-slow:400ms;
}

/* 2 重置 ---------------------------------------------------------------- */
*,*::before,*::after{box-sizing:border-box}
html{
  -webkit-text-size-adjust:100%;
  scroll-behavior:smooth;
  scroll-padding-top:120px;
}
body,h1,h2,h3,h4,h5,h6,p,ul,ol,li,figure,figcaption,blockquote,dl,dd,address{margin:0}
ul,ol{padding:0}
ul[class],ol[class]{list-style:none}
img,svg,video{display:block;max-width:100%}
a{color:inherit;text-decoration:none}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer}
table{border-collapse:collapse;width:100%}

/* 3 基础排版 ------------------------------------------------------------ */
body{
  min-height:100vh;
  overflow-x:hidden;
  background:var(--paper);
  color:var(--indigo);
  font-family:var(--font-body);
  font-size:var(--step-body);
  line-height:1.85;
  -webkit-font-smoothing:antialiased;
}
h1,h2,h3,h4,h5,h6{
  font-family:var(--font-display);
  font-weight:900;
  line-height:1.18;
  letter-spacing:.02em;
  color:var(--indigo);
}
h1{font-size:var(--step-hero);line-height:1.04;letter-spacing:.01em}
h2{font-size:var(--step-title)}
h3{font-size:clamp(1.1rem,1.6vw,1.35rem);font-weight:700}
h4{font-size:1rem;font-weight:700}
p{max-width:100%}
strong{font-weight:700}
code,kbd,samp,.mono{
  font-family:var(--font-mono);
  font-size:.9em;
  letter-spacing:.06em;
}
::selection{background:var(--amber-light);color:var(--ink-deep)}

.prose{
  max-width:30em;
  font-size:var(--step-body);
  line-height:1.85;
  color:var(--indigo);
}
.prose p+p{margin-top:1.1em}
.prose h2{margin:2.2em 0 .8em}
.prose h3{margin:1.8em 0 .6em}
.prose ul{margin:1em 0;padding-left:1.2em;list-style:disc}
.prose li+li{margin-top:.45em}

.lede{
  font-size:clamp(1.0625rem,1.5vw,1.25rem);
  line-height:1.8;
  color:var(--ink-deep);
  max-width:32em;
}

/* 4 布局原子 ------------------------------------------------------------ */
.container{
  width:100%;
  max-width:var(--maxw);
  margin:0 auto;
  padding-left:var(--page-x);
  padding-right:var(--page-x);
}
.container--narrow{max-width:860px}

.section{padding:clamp(36px,7vw,96px) 0}
.section__head{display:grid;gap:.85rem;margin-bottom:clamp(20px,3vw,42px)}
.section__num{
  font-family:var(--font-mono);
  font-size:var(--step-meta);
  letter-spacing:.18em;
  color:var(--amber);
}
.section__title{
  font-family:var(--font-display);
  font-weight:900;
  font-size:var(--step-title);
  line-height:1.25;
  letter-spacing:.02em;
}
.section__lead{
  max-width:30em;
  font-size:.9375rem;
  line-height:1.8;
  color:var(--gray-brown);
}

.rule{
  height:1px;
  width:100%;
  background:var(--rule);
  border:0;
}
.rule--amber{
  height:3px;
  width:18%;
  background:var(--amber);
}

.grid{display:grid;gap:var(--gutter)}
.grid--5-7{grid-template-columns:5fr 7fr}
.grid--4-8{grid-template-columns:4fr 8fr}
.grid--3-6-3{grid-template-columns:3fr 6fr 3fr}

.stack{display:grid;gap:var(--gutter)}

.plate{
  position:relative;
  padding:clamp(18px,2.4vw,30px);
  background:#FBF8F1;
  border:1px solid var(--rule);
  border-radius:var(--radius);
  box-shadow:var(--shadow-plate);
  font-family:var(--font-display);
  font-weight:400;
}
.plate--offset{margin-top:-14px}

.hero-diagonal{
  position:relative;
  isolation:isolate;
  overflow:hidden;
  padding:clamp(40px,8vw,112px) 0 clamp(52px,9vw,132px);
}
.hero-diagonal__shard{
  position:absolute;
  z-index:0;
  top:-20%;
  right:-14%;
  width:78%;
  height:142%;
  background:var(--indigo);
  transform:rotate(-8deg);
  pointer-events:none;
}
.hero-diagonal__shard--deep{
  top:-14%;
  right:4%;
  width:32%;
  height:128%;
  background:var(--ink-deep);
  opacity:.94;
}
.hero-diagonal>.container{position:relative;z-index:1}

/* 5 信息组件 ------------------------------------------------------------ */
.tag{
  display:inline-flex;
  align-items:center;
  gap:.4em;
  padding:.22rem .6rem;
  border:1px solid var(--rule);
  border-radius:2px;
  background:rgba(255,255,255,.45);
  color:var(--gray-brown);
  font-family:var(--font-display);
  font-size:var(--step-meta);
  font-weight:500;
  letter-spacing:.04em;
  line-height:1.6;
}
.tag--celadon{border-color:rgba(78,140,122,.5);background:rgba(78,140,122,.09);color:var(--celadon)}
.tag--amber{border-color:rgba(200,145,47,.5);background:rgba(200,145,47,.11);color:#9A6C1C}
.tag--coral{border-color:rgba(217,88,74,.5);background:rgba(217,88,74,.09);color:var(--coral)}

.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:.5em;
  padding:.72rem 1.35rem;
  border:1px solid var(--indigo);
  border-radius:2px;
  background:transparent;
  color:var(--indigo);
  font-family:var(--font-display);
  font-size:.9375rem;
  font-weight:700;
  letter-spacing:.06em;
  line-height:1.4;
  transition:background var(--dur-fast) var(--ease),color var(--dur-fast) var(--ease),border-color var(--dur-fast) var(--ease);
}
.btn--solid{background:var(--indigo);color:var(--paper)}
.btn--solid:hover{background:var(--ink-deep);border-color:var(--ink-deep)}
.btn--ghost:hover{background:var(--indigo);color:var(--paper)}
.btn--amber{background:var(--amber);border-color:var(--amber);color:#FFF9EC}
.btn--amber:hover{background:#B07F26;border-color:#B07F26}
.btn--coral{border-color:var(--coral);color:var(--coral)}
.btn--coral:hover{background:var(--coral);color:#FFF7F5}

.breadcrumb{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:.5rem;
  padding:clamp(14px,2vw,26px) 0;
  font-family:var(--font-mono);
  font-size:.75rem;
  letter-spacing:.06em;
  color:var(--gray-brown);
}
.breadcrumb__item{display:inline-flex;align-items:center;gap:.5rem}
.breadcrumb__item+.breadcrumb__item::before{content:"/";color:var(--rule)}
.breadcrumb a{transition:color var(--dur-fast) var(--ease)}
.breadcrumb a:hover{color:var(--amber)}
.breadcrumb [aria-current="page"]{color:var(--indigo)}

.filter-bar{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:.55rem;
  margin-bottom:clamp(18px,2.6vw,30px);
}
.filter-chip{
  padding:.42rem .9rem;
  border:1px solid var(--rule);
  border-radius:999px;
  background:transparent;
  color:var(--gray-brown);
  font-family:var(--font-display);
  font-size:var(--step-meta);
  font-weight:500;
  letter-spacing:.04em;
  transition:background var(--dur-fast) var(--ease),border-color var(--dur-fast) var(--ease),color var(--dur-fast) var(--ease);
}
.filter-chip:hover{border-color:var(--amber);color:var(--indigo)}
.filter-chip[aria-pressed="true"]{
  background:var(--amber-light);
  border-color:var(--amber);
  color:var(--ink-deep);
  font-weight:700;
}
.filter-status{
  font-family:var(--font-mono);
  font-size:var(--step-meta);
  letter-spacing:.06em;
  color:var(--gray-brown);
  margin-left:.4rem;
}

.index-axis{
  display:flex;
  flex-direction:column;
  position:sticky;
  top:calc(84px + 1.5rem);
  border-left:1px solid var(--rule);
  padding-left:0;
}
.index-axis__node{
  display:flex;
  align-items:center;
  gap:.7rem;
  padding:.5rem .8rem;
  color:var(--gray-brown);
  font-family:var(--font-mono);
  font-size:var(--step-meta);
  letter-spacing:.06em;
  text-align:left;
  transition:color var(--dur-mid) var(--ease);
}
.index-axis__node::before{
  content:"";
  flex:0 0 auto;
  width:9px;
  height:9px;
  margin-left:-5px;
  border:1px solid var(--amber);
  border-radius:50%;
  background:transparent;
  transition:background var(--dur-mid) var(--ease);
}
.index-axis__node:hover{color:var(--indigo)}
.index-axis__node[aria-current="true"]{color:var(--ink-deep)}
.index-axis__node[aria-current="true"]::before{background:var(--amber)}

.media-frame{
  position:relative;
  overflow:hidden;
  width:100%;
  border:1px solid var(--rule);
  border-radius:var(--radius);
  background:linear-gradient(158deg,#EDE6D8 0%,#F4EFE4 58%,#E7DFCF 100%);
}
.media-frame img{width:100%;height:100%;object-fit:cover}
.media-frame--wide{aspect-ratio:16/9}
.media-frame--tall{aspect-ratio:3/4}
.media-frame--square{aspect-ratio:1/1}
.media-frame__caption{
  margin-top:.6rem;
  font-size:var(--step-meta);
  letter-spacing:.04em;
  color:var(--gray-brown);
}

.is-hidden{display:none !important}
.visually-hidden{
  position:absolute !important;
  width:1px;height:1px;
  padding:0;margin:-1px;
  overflow:hidden;
  clip:rect(0 0 0 0);
  white-space:nowrap;
  border:0;
}

/* 6 页头 ---------------------------------------------------------------- */
.skip-link{
  position:fixed;
  top:-80px;
  left:16px;
  z-index:200;
  padding:.65rem 1.1rem;
  background:var(--indigo);
  color:var(--paper);
  border-radius:2px;
  font-family:var(--font-display);
  font-size:var(--step-meta);
  letter-spacing:.06em;
  transition:top var(--dur-fast) var(--ease);
}
.skip-link:focus{top:16px}

.site-header{
  position:sticky;
  top:0;
  z-index:80;
  background:var(--paper);
  border-bottom:1px solid var(--rule);
  transition:box-shadow var(--dur-fast) linear;
}
.site-header[data-stuck]{box-shadow:0 12px 32px rgba(27,42,74,.08)}

.masthead{
  width:100%;
  max-width:var(--maxw);
  margin:0 auto;
  padding:clamp(10px,1.6vw,18px) var(--page-x) 0;
}

.masthead__meta{
  display:flex;
  justify-content:space-between;
  align-items:center;
  gap:16px;
  overflow:hidden;
  max-height:60px;
  padding-bottom:clamp(8px,1.2vw,14px);
  color:var(--gray-brown);
  font-family:var(--font-mono);
  font-size:.75rem;
  letter-spacing:.06em;
  transition:max-height .28s var(--ease),opacity .2s linear,padding .28s var(--ease);
}
.masthead__geo{display:inline-flex;align-items:center;gap:.55em}
.masthead__geo::before{
  content:"";
  width:6px;
  height:6px;
  border-radius:50%;
  background:var(--celadon);
}
.masthead__update{color:var(--gray-brown)}

.masthead__brand{
  position:relative;
  display:flex;
  justify-content:center;
  align-items:center;
  overflow:hidden;
  max-height:240px;
  padding:clamp(6px,1.4vw,16px) 0 clamp(10px,1.6vw,20px);
  transition:max-height .32s var(--ease),opacity .2s linear,padding .32s var(--ease);
}
.brand{display:flex;flex-direction:column;align-items:center;line-height:1}
.brand__name{
  font-family:var(--font-display);
  font-weight:900;
  font-size:clamp(2rem,6vw,4.4rem);
  letter-spacing:.08em;
  color:var(--indigo);
}
.brand__sub{
  margin-top:.6em;
  padding-left:.42em;
  color:var(--amber);
  font-family:var(--font-mono);
  font-size:.75rem;
  letter-spacing:.42em;
}
.feedback-chip{
  position:absolute;
  right:0;
  top:50%;
  transform:translateY(-50%);
  padding:.45rem .9rem;
  border:1px solid var(--coral);
  border-radius:2px;
  color:var(--coral);
  font-family:var(--font-display);
  font-size:var(--step-meta);
  font-weight:500;
  letter-spacing:.06em;
  white-space:nowrap;
  transition:background var(--dur-fast) var(--ease),color var(--dur-fast) var(--ease);
}
.feedback-chip:hover{background:var(--coral);color:#FFF7F5}

.site-header[data-stuck] .masthead__meta{max-height:0;opacity:0;padding-bottom:0}
.site-header[data-stuck] .masthead__brand{max-height:0;opacity:0;padding-top:0;padding-bottom:0}

.masthead__nav{position:relative}
.nav-toggle{display:none}
.nav-list{
  display:flex;
  justify-content:center;
  align-items:center;
  flex-wrap:wrap;
  gap:clamp(12px,3vw,44px);
  padding:0 0 clamp(10px,1.6vw,18px);
}
.nav-list__item{display:flex}
.nav-link{
  position:relative;
  display:inline-block;
  padding:.35rem 0 .5rem;
  color:var(--indigo);
  font-family:var(--font-display);
  font-size:.9375rem;
  font-weight:500;
  letter-spacing:.06em;
  transition:color var(--dur-fast) var(--ease);
}
.nav-link::after{
  content:"";
  position:absolute;
  left:0;
  bottom:.18rem;
  width:100%;
  height:2px;
  background:var(--amber);
  transform:scaleX(0);
  transform-origin:left center;
  transition:transform var(--dur-fast) var(--ease);
}
.nav-link:hover{color:var(--ink-deep)}
.nav-link:hover::after,
.nav-link[aria-current="page"]::after{transform:scaleX(1)}
.nav-link[aria-current="page"]{color:var(--indigo);font-weight:700}

/* 7 页脚 ---------------------------------------------------------------- */
.site-footer{
  position:relative;
  overflow:hidden;
  margin-top:clamp(56px,9vw,140px);
  padding-top:clamp(36px,7vw,88px);
  background:var(--indigo);
  color:var(--paper);
}
.footer__contour{
  position:absolute;
  inset:0;
  pointer-events:none;
  background-image:
    repeating-linear-gradient(168deg,rgba(244,239,228,.055) 0 1px,transparent 1px 34px),
    repeating-linear-gradient(78deg,rgba(244,239,228,.04) 0 1px,transparent 1px 58px);
}
.footer__inner{
  position:relative;
  z-index:1;
  width:100%;
  max-width:var(--maxw);
  margin:0 auto;
  padding:0 var(--page-x);
}
.footer__crest{
  position:relative;
  padding-top:14px;
  padding-bottom:clamp(22px,4vw,44px);
  border-bottom:1px solid rgba(244,239,228,.18);
}
.footer__crest::before{
  content:"";
  position:absolute;
  top:0;
  left:0;
  width:18%;
  min-width:64px;
  height:3px;
  background:var(--amber);
}
.footer__brand{
  font-family:var(--font-display);
  font-weight:900;
  font-size:clamp(1.5rem,3vw,2.2rem);
  letter-spacing:.1em;
  color:var(--paper);
}
.footer__tagline{
  margin-top:.55rem;
  max-width:34em;
  color:rgba(244,239,228,.68);
  font-family:var(--font-display);
  font-size:.875rem;
  letter-spacing:.04em;
  line-height:1.8;
}
.footer__grid{
  display:grid;
  grid-template-columns:1.15fr 1fr;
  gap:clamp(26px,5vw,76px);
  padding:clamp(28px,4.4vw,60px) 0;
}
.footer__col--links{justify-self:end;width:100%}
.footer__heading{
  margin-bottom:1.1rem;
  color:var(--amber-light);
  font-family:var(--font-mono);
  font-size:.75rem;
  letter-spacing:.18em;
}
.footer__contact{display:grid;gap:.95rem;list-style:none}
.footer__contact-row{
  display:flex;
  flex-wrap:wrap;
  align-items:baseline;
  gap:.35rem .8rem;
}
.footer__contact-label{
  flex:0 0 auto;
  min-width:2.6em;
  color:rgba(244,239,228,.5);
  font-family:var(--font-mono);
  font-size:.75rem;
  letter-spacing:.14em;
}
.footer__value{
  color:var(--paper);
  font-family:var(--font-mono);
  font-size:.9375rem;
  letter-spacing:.04em;
  word-break:break-word;
}
.copy-btn{
  padding:.2rem .6rem;
  border:1px solid rgba(244,239,228,.28);
  border-radius:2px;
  color:rgba(244,239,228,.82);
  font-family:var(--font-mono);
  font-size:.75rem;
  letter-spacing:.08em;
  transition:border-color var(--dur-fast) var(--ease),color var(--dur-fast) var(--ease);
}
.copy-btn:hover{border-color:var(--amber-light);color:var(--amber-light)}
.copy-btn[data-copied]{border-color:var(--celadon);color:#8FC7B4}
.footer__note{
  margin-top:.9rem;
  max-width:28em;
  color:rgba(244,239,228,.55);
  font-size:var(--step-meta);
  letter-spacing:.04em;
  line-height:1.8;
}
.footer__list{
  display:flex;
  flex-wrap:wrap;
  gap:.6rem 1.8rem;
  list-style:none;
}
.footer__link{
  display:inline-block;
  padding-bottom:.15rem;
  border-bottom:1px solid transparent;
  color:rgba(244,239,228,.84);
  font-family:var(--font-display);
  font-size:.9375rem;
  letter-spacing:.04em;
  transition:color var(--dur-fast) var(--ease),border-color var(--dur-fast) var(--ease);
}
.footer__link:hover{color:#FFFFFF;border-color:var(--amber-light)}
.footer__base{
  padding:1.5rem 0 1.8rem;
  border-top:1px solid rgba(244,239,228,.18);
  text-align:center;
  color:rgba(244,239,228,.62);
  font-family:var(--font-mono);
  font-size:var(--step-meta);
  letter-spacing:.06em;
  line-height:1.9;
}

.to-top{
  position:fixed;
  right:clamp(14px,3vw,28px);
  bottom:clamp(14px,3vw,28px);
  z-index:70;
  display:none;
  width:44px;
  height:44px;
  place-items:center;
  border:1px solid var(--rule);
  border-radius:50%;
  background:var(--paper);
  color:var(--indigo);
  font-family:var(--font-mono);
  font-size:.9375rem;
  box-shadow:var(--shadow-plate);
  transition:border-color var(--dur-fast) var(--ease),color var(--dur-fast) var(--ease);
}
.to-top:hover{border-color:var(--amber);color:var(--amber)}
body[data-scrolled] .to-top{display:grid}

/* 8 响应式 -------------------------------------------------------------- */
@media (max-width:900px){
  .grid--5-7,.grid--4-8,.grid--3-6-3{grid-template-columns:1fr}
  .index-axis{position:static}
}

@media (max-width:880px){
  html{scroll-padding-top:96px}

  .masthead__brand{max-height:280px;padding-bottom:clamp(12px,3vw,20px)}
  .brand__name{letter-spacing:.06em}
  .brand__sub{letter-spacing:.3em;padding-left:.3em}

  .nav-toggle{
    display:inline-flex;
    align-items:center;
    justify-content:center;
    gap:.7em;
    width:100%;
    padding:.85rem 1rem;
    border-top:1px solid var(--rule);
    color:var(--indigo);
    font-family:var(--font-display);
    font-size:.875rem;
    font-weight:700;
    letter-spacing:.12em;
  }
  .nav-toggle::after{
    content:"打开";
    color:var(--gray-brown);
    font-family:var(--font-mono);
    font-size:.75rem;
    font-weight:400;
    letter-spacing:.08em;
  }
  [data-nav][data-open] .nav-toggle::after{content:"收起";color:var(--amber)}

  .nav-list{
    display:none;
    flex-direction:column;
    align-items:stretch;
    gap:0;
    padding:0 0 .5rem;
  }
  [data-nav][data-open] .nav-list{display:flex}
  .nav-list__item{
    display:block;
    border-bottom:1px solid var(--rule);
  }
  .nav-link{
    display:flex;
    justify-content:space-between;
    align-items:center;
    width:100%;
    padding:.9rem 2px;
    font-size:1rem;
    font-weight:500;
  }
  .nav-link::after{
    content:"→";
    position:static;
    width:auto;
    height:auto;
    background:none;
    transform:none;
    color:var(--amber);
    transition:none;
  }
  .nav-link[aria-current="page"]{font-weight:700}

  .feedback-chip{
    position:static;
    transform:none;
    margin-top:.9rem;
    align-self:center;
  }
  .masthead__brand{flex-direction:column}
}

@media (max-width:760px){
  .footer__grid{grid-template-columns:1fr}
  .footer__col--links{justify-self:start}
  .footer__list{gap:.5rem 1.25rem}

  .index-axis{
    flex-direction:row;
    align-items:center;
    gap:.3rem;
    overflow-x:auto;
    border-left:0;
    border-bottom:1px solid var(--rule);
    padding-bottom:.45rem;
    margin-bottom:1.5rem;
  }
  .index-axis__node{
    flex:0 0 auto;
    padding:.35rem .6rem;
    white-space:nowrap;
  }
}

@media (max-width:520px){
  .masthead__meta{flex-direction:column;align-items:flex-start;gap:4px}
  .brand__name{font-size:clamp(1.8rem,11vw,2.6rem)}
  .tag{font-size:.75rem}
}

/* 9 可访问性 ------------------------------------------------------------ */
:focus-visible{
  outline:2px solid var(--amber);
  outline-offset:2px;
  border-radius:2px;
}
a:focus-visible,button:focus-visible{outline-offset:3px}

@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;
  }
}