/* ============================================================
   长乐坊备用站 · 共享样式表 /assets/site.css
   分层：1 变量与重置 2 排版 3 通用组件 4 页头 5 页脚 6 响应式
   ============================================================ */

/* ---------- 1 · 变量与重置 ---------- */
:root{
  --c-dai:#12333C;
  --c-night:#0A2129;
  --c-silver:#C6CCCE;
  --c-paper:#F4EFE4;
  --c-amber:#D9983F;
  --c-amber-soft:#F0CE95;
  --c-cinnabar:#A6483A;
  --c-jade:#45665C;
  --c-ink:#101A1E;

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

  --shell:1200px;
  --gutter:24px;
  --radius:0px;
  --shadow-hard:6px 6px 0 rgba(16,26,30,.16);
  --shadow-soft:4px 4px 0 rgba(16,26,30,.12);
  --ease:160ms cubic-bezier(.2,.7,.3,1);
}

*,*::before,*::after{box-sizing:border-box}
html{
  -webkit-text-size-adjust:100%;
  scroll-behavior:smooth;
  scroll-padding-top:170px;
}
body,h1,h2,h3,h4,h5,p,ul,ol,li,figure,blockquote,dl,dd{margin:0}
ul,ol{padding:0;list-style:none}
img,svg,video{display:block;max-width:100%}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer}
table{border-collapse:collapse;width:100%}

body{
  background:var(--c-paper);
  color:var(--c-ink);
  font-family:var(--font-body);
  font-size:17px;
  line-height:1.8;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}

:focus-visible{
  outline:3px solid var(--c-amber);
  outline-offset:2px;
}

::selection{background:var(--c-amber-soft);color:var(--c-ink)}

#main-content{display:block}

/* ---------- 2 · 排版 ---------- */
h1,h2,h3,h4{font-family:var(--font-display);font-weight:800;line-height:1.24;letter-spacing:.01em;color:var(--c-dai)}
h1{font-size:clamp(34px,5vw,56px)}
h2{font-size:clamp(26px,3.4vw,38px)}
h3{font-size:clamp(20px,2.2vw,26px)}
h4{font-size:18px;line-height:1.4}

p{max-width:68ch}
strong{font-weight:700}
a{color:var(--c-jade);text-decoration:none}
a:hover{color:var(--c-cinnabar)}

.mono{
  font-family:var(--font-mono);
  font-size:.82em;
  letter-spacing:.06em;
}

/* ---------- 3 · 通用组件 ---------- */
.skip-link{
  position:absolute;
  left:16px;
  top:-120px;
  z-index:200;
  padding:12px 18px;
  background:var(--c-amber);
  color:var(--c-ink);
  font-weight:700;
  border:2px solid var(--c-ink);
  box-shadow:var(--shadow-soft);
  transition:top var(--ease);
}
.skip-link:focus{top:16px;color:var(--c-ink)}

.container{
  width:100%;
  max-width:var(--shell);
  margin-inline:auto;
  padding-inline:var(--gutter);
}

.section{padding-block:64px}
.section--dark{background:var(--c-dai);color:var(--c-paper)}
.section--dark h1,.section--dark h2,.section--dark h3,.section--dark h4{color:var(--c-paper)}
.section--paper{background:var(--c-paper)}

.rule{height:2px;background:var(--c-dai);border:0}
.section--dark .rule{background:rgba(198,204,206,.45)}

.stack{display:flex;flex-direction:column;gap:16px}

.grid{display:grid;gap:24px}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid--split{grid-template-columns:minmax(0,.85fr) minmax(0,1.65fr);gap:40px}

.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:10px;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.2em;
  text-transform:uppercase;
  color:var(--c-jade);
}
.eyebrow::before{content:"";width:26px;height:2px;background:var(--c-amber)}
.section--dark .eyebrow{color:var(--c-amber-soft)}

.tag{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:2px 9px;
  border:1px solid currentColor;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.06em;
  line-height:1.6;
  white-space:nowrap;
}
.tag--amber{color:var(--c-ink);background:var(--c-amber-soft);border-color:var(--c-amber)}
.tag--jade{color:var(--c-jade);background:rgba(69,102,92,.12)}
.tag--alarm{color:var(--c-paper);background:var(--c-cinnabar);border-color:var(--c-cinnabar)}
.tag--plain{color:var(--c-ink);background:transparent;border-color:var(--c-silver)}
.section--dark .tag--plain{color:var(--c-paper);border-color:rgba(198,204,206,.5)}

.btn{
  display:inline-flex;
  align-items:center;
  gap:10px;
  padding:12px 22px;
  border:2px solid var(--c-ink);
  background:var(--c-paper);
  color:var(--c-ink);
  font-size:15px;
  font-weight:700;
  line-height:1.2;
  box-shadow:var(--shadow-soft);
  transition:transform var(--ease),box-shadow var(--ease),background-color var(--ease),color var(--ease),border-color var(--ease);
}
.btn:hover,.btn:focus-visible{
  transform:translate(-2px,-2px);
  box-shadow:var(--shadow-hard);
  background:var(--c-amber-soft);
  color:var(--c-ink);
}
.btn:active{transform:translate(1px,1px);box-shadow:2px 2px 0 rgba(16,26,30,.16)}
.btn--primary{background:var(--c-amber);border-color:var(--c-ink)}
.btn--primary:hover,.btn--primary:focus-visible{background:var(--c-amber-soft)}
.btn--ghost{background:transparent;border-color:var(--c-silver);box-shadow:none;color:var(--c-dai)}
.btn--ghost:hover,.btn--ghost:focus-visible{background:var(--c-dai);border-color:var(--c-amber);color:var(--c-paper)}
.btn--on-dark{background:transparent;border-color:var(--c-silver);color:var(--c-paper);box-shadow:4px 4px 0 rgba(198,204,206,.28)}
.btn--on-dark:hover,.btn--on-dark:focus-visible{background:rgba(217,152,63,.18);border-color:var(--c-amber);color:var(--c-amber-soft)}

.breadcrumb{font-family:var(--font-mono);font-size:12px;letter-spacing:.06em;color:var(--c-jade)}
.breadcrumb ol{display:flex;flex-wrap:wrap;gap:8px;align-items:center}
.breadcrumb li+li::before{content:"/";margin-right:8px;color:var(--c-silver)}
.breadcrumb a{color:inherit;border-bottom:1px solid transparent;transition:color var(--ease),border-color var(--ease)}
.breadcrumb a:hover{color:var(--c-amber);border-bottom-color:var(--c-amber)}

.prose{max-width:38em;font-size:17px;line-height:1.85}
.prose p+p{margin-top:1em}
.prose h2{font-size:26px;margin:1.8em 0 .6em}
.prose h3{font-size:20px;margin:1.4em 0 .5em}
.prose ul{list-style:none;margin-block:.8em}
.prose li{padding-left:20px;position:relative}
.prose li::before{content:"";position:absolute;left:0;top:.75em;width:8px;height:2px;background:var(--c-amber)}
.prose a{color:var(--c-jade);border-bottom:2px solid var(--c-amber);transition:color var(--ease)}
.prose a:hover{color:var(--c-cinnabar)}

.card{
  background:var(--c-paper);
  border:1px solid var(--c-silver);
  border-left:6px solid var(--c-dai);
  padding:22px 24px;
  box-shadow:var(--shadow-soft);
  transition:transform var(--ease),border-color var(--ease),box-shadow var(--ease),background-color var(--ease);
}
.card:hover,.card:focus-within{
  transform:translateY(-4px);
  border-left-color:var(--c-amber);
  box-shadow:var(--shadow-hard);
  background:#FFFCF5;
}
.card__title{font-family:var(--font-display);font-size:20px;font-weight:800;color:var(--c-dai);line-height:1.35}
.card__meta{font-family:var(--font-mono);font-size:12px;letter-spacing:.06em;color:var(--c-jade)}

.index-row{
  display:grid;
  grid-template-columns:96px minmax(0,1fr);
  gap:22px;
  padding:20px 0;
  border-bottom:1px solid rgba(198,204,206,.85);
  transition:background-color var(--ease),border-color var(--ease);
}
.index-row:hover{background:rgba(240,206,149,.32);border-bottom-color:var(--c-amber)}
.index-row__num{
  font-family:var(--font-mono);
  font-size:13px;
  letter-spacing:.06em;
  color:var(--c-amber);
  text-align:right;
  padding-top:3px;
}
.index-row__body{display:flex;flex-direction:column;gap:8px}

.anchor-rail{
  position:sticky;
  top:170px;
  display:grid;
  gap:2px;
  align-content:start;
}
.anchor-rail__link{
  display:grid;
  grid-template-columns:auto minmax(0,1fr);
  gap:10px;
  padding:10px 12px;
  border-left:3px solid var(--c-silver);
  font-size:14px;
  line-height:1.5;
  color:var(--c-dai);
  transition:border-color var(--ease),background-color var(--ease),color var(--ease),transform var(--ease);
}
.anchor-rail__link:hover{border-left-color:var(--c-amber);background:rgba(240,206,149,.3);transform:translateX(2px)}
.anchor-rail__link[aria-current="true"]{
  border-left-color:var(--c-amber);
  background:rgba(240,206,149,.45);
  font-weight:700;
  color:var(--c-ink);
}

.media-frame{
  position:relative;
  display:block;
  width:100%;
  overflow:hidden;
  background:var(--c-dai);
  border:2px solid var(--c-dai);
  box-shadow:var(--shadow-soft);
}
.media-frame--wide{aspect-ratio:16/9}
.media-frame--photo{aspect-ratio:4/3}
.media-frame--tall{aspect-ratio:3/4}
.media-frame--square{aspect-ratio:1/1}
.media-frame__img{
  width:100%;
  height:100%;
  object-fit:cover;
  filter:saturate(.94) contrast(1.03);
}
.media-frame__placeholder{
  position:absolute;
  inset:0;
  display:grid;
  place-items:center;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.1em;
  color:var(--c-dai);
  background:
    repeating-linear-gradient(135deg,rgba(198,204,206,.55) 0 10px,rgba(244,239,228,0) 10px 20px),
    var(--c-paper);
}
.media-frame__caption{
  display:block;
  margin-top:10px;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.04em;
  color:var(--c-jade);
  border-left:3px solid var(--c-amber);
  padding-left:10px;
}

/* ---------- 4 · 页头 ---------- */
.stripe-rule{
  height:6px;
  background:repeating-linear-gradient(90deg,
    var(--c-amber) 0 22px,
    var(--c-night) 22px 26px,
    var(--c-silver) 26px 29px,
    var(--c-night) 29px 56px);
}

.site-header{
  position:sticky;
  top:0;
  z-index:60;
  background:var(--c-night);
  color:var(--c-paper);
  border-bottom:2px solid var(--c-amber);
}

.header-shell{
  max-width:var(--shell);
  margin-inline:auto;
  padding:18px var(--gutter) 0;
  display:grid;
  grid-template-columns:minmax(0,1fr) auto minmax(0,1fr);
  grid-template-areas:
    "search masthead status"
    "nav nav nav";
  align-items:center;
  column-gap:20px;
  row-gap:14px;
  transition:padding var(--ease),row-gap var(--ease);
}

.header-search{
  grid-area:search;
  justify-self:start;
  display:inline-flex;
  align-items:center;
  gap:10px;
  max-width:270px;
  min-width:0;
  padding:8px 14px;
  border:1px solid rgba(198,204,206,.45);
  color:var(--c-paper);
  transition:border-color var(--ease),background-color var(--ease),color var(--ease);
}
.header-search:hover,.header-search:focus-visible{
  border-color:var(--c-amber);
  background:rgba(217,152,63,.16);
  color:var(--c-amber-soft);
}
.header-search__label{
  flex:none;
  font-size:12px;
  letter-spacing:.16em;
  color:var(--c-amber);
}
.header-search__value{
  min-width:0;
  font-size:13px;
  line-height:1.3;
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
}

.masthead{
  grid-area:masthead;
  justify-self:center;
  display:flex;
  align-items:center;
  gap:16px;
  min-width:0;
}
.brand{display:flex;align-items:center;gap:12px;color:var(--c-paper)}
.brand:hover{color:var(--c-paper)}
.brand__seal{
  flex:none;
  width:40px;
  height:40px;
  display:grid;
  place-items:center;
  border:2px solid var(--c-amber);
  background:rgba(217,152,63,.12);
  color:var(--c-amber);
  font-family:var(--font-display);
  font-size:22px;
  font-weight:800;
  line-height:1;
  transition:width var(--ease),height var(--ease),font-size var(--ease);
}
.brand__text{display:flex;flex-direction:column;gap:3px;min-width:0}
.brand__name{
  font-family:var(--font-display);
  font-size:26px;
  font-weight:800;
  letter-spacing:.08em;
  line-height:1.1;
  white-space:nowrap;
  transition:font-size var(--ease);
}
.brand__sub{
  font-size:11px;
  letter-spacing:.2em;
  color:var(--c-silver);
  white-space:nowrap;
}
.brand__edition{
  flex:none;
  padding-left:16px;
  border-left:1px solid rgba(198,204,206,.4);
  font-size:12px;
  letter-spacing:.12em;
  color:var(--c-silver);
  white-space:nowrap;
}
.brand__edition-key{color:var(--c-amber)}

.header-status{
  grid-area:status;
  justify-self:end;
  display:inline-flex;
  align-items:center;
  gap:8px;
  max-width:none;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.1em;
  color:var(--c-silver);
  white-space:nowrap;
}
.header-status__dot{
  width:8px;
  height:8px;
  flex:none;
  background:var(--c-jade);
  box-shadow:0 0 0 3px rgba(69,102,92,.35);
}

.site-nav{
  grid-area:nav;
  border-top:1px solid rgba(198,204,206,.28);
  padding-top:12px;
  padding-bottom:14px;
  transition:padding var(--ease);
}
.site-nav__list{
  display:flex;
  flex-wrap:wrap;
  justify-content:center;
  gap:8px;
}
.site-nav__link{
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:8px 14px;
  border:1px solid rgba(198,204,206,.35);
  color:var(--c-paper);
  font-size:15px;
  line-height:1.2;
  transition:border-color var(--ease),background-color var(--ease),color var(--ease),transform var(--ease),padding var(--ease);
}
.site-nav__index{font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;color:var(--c-amber)}
.site-nav__link:hover,.site-nav__link:focus-visible{
  border-color:var(--c-amber);
  background:rgba(217,152,63,.16);
  color:var(--c-amber-soft);
  transform:translateY(-2px);
}
.site-nav__link[aria-current="page"]{
  background:var(--c-amber);
  border-color:var(--c-amber);
  color:var(--c-ink);
  font-weight:700;
}
.site-nav__link[aria-current="page"] .site-nav__index{color:var(--c-ink);opacity:.72}

.nav-toggle{
  display:none;
  grid-area:toggle;
  justify-self:end;
  align-items:center;
  gap:10px;
  padding:10px 12px;
  border:1px solid rgba(198,204,206,.45);
  color:var(--c-paper);
  transition:border-color var(--ease),background-color var(--ease),color var(--ease);
}
.nav-toggle:hover,.nav-toggle:focus-visible{border-color:var(--c-amber);color:var(--c-amber-soft)}
.nav-toggle[aria-expanded="true"]{border-color:var(--c-amber);background:rgba(217,152,63,.18);color:var(--c-amber-soft)}
.nav-toggle__label{font-size:12px;letter-spacing:.16em}
.nav-toggle__bars{display:grid;gap:4px;width:18px}
.nav-toggle__bars i{display:block;height:2px;background:currentColor}

/* 滚动后收为细窄色带 */
.site-header[data-compact] .header-shell{padding-top:9px;row-gap:8px}
.site-header[data-compact] .brand__name{font-size:20px}
.site-header[data-compact] .brand__sub{display:none}
.site-header[data-compact] .brand__seal{width:30px;height:30px;font-size:17px}
.site-header[data-compact] .header-search__value{display:none}
.site-header[data-compact] .site-nav{padding-top:8px;padding-bottom:9px}
.site-header[data-compact] .site-nav__link{padding:6px 12px;font-size:14px}

/* ---------- 5 · 页脚 ---------- */
.site-footer{
  background:var(--c-night);
  color:var(--c-paper);
  border-top:2px solid var(--c-amber);
}
.footer-shell{
  max-width:var(--shell);
  margin-inline:auto;
  padding:52px var(--gutter) 8px;
  display:grid;
  grid-template-columns:1.6fr repeat(4,minmax(0,1fr));
  gap:32px 28px;
}
.footer-brand{display:flex;flex-direction:column;gap:10px;max-width:320px}
.footer-brand__name{
  font-family:var(--font-display);
  font-size:26px;
  font-weight:800;
  letter-spacing:.08em;
  color:var(--c-paper);
}
.footer-brand__sub{font-size:12px;letter-spacing:.16em;color:var(--c-amber)}
.footer-brand__note{font-size:14px;line-height:1.75;color:var(--c-silver);max-width:32ch}

.footer-col{display:flex;flex-direction:column;gap:14px;min-width:0}
.footer-col__title{
  font-size:12px;
  font-weight:400;
  letter-spacing:.18em;
  color:var(--c-amber);
  padding-bottom:8px;
  border-bottom:1px solid rgba(198,204,206,.28);
}
.footer-list{display:flex;flex-direction:column;gap:9px;font-size:14px;line-height:1.6}
.footer-list a{
  color:var(--c-silver);
  border-bottom:2px solid transparent;
  transition:color var(--ease),border-color var(--ease);
}
.footer-list a:hover,.footer-list a:focus-visible{color:var(--c-amber-soft);border-bottom-color:var(--c-amber)}
.footer-text{
  display:block;
  font-family:var(--font-mono);
  font-size:12.5px;
  letter-spacing:.04em;
  color:var(--c-silver);
  word-break:break-word;
}

.footer-bottom{
  border-top:1px solid rgba(198,204,206,.24);
  margin-top:44px;
}
.footer-bottom__inner{
  max-width:var(--shell);
  margin-inline:auto;
  padding:18px var(--gutter) 30px;
  display:flex;
  flex-wrap:wrap;
  gap:8px 28px;
  align-items:baseline;
}
.footer-bottom__meta{
  max-width:none;
  font-size:12px;
  letter-spacing:.06em;
  color:var(--c-silver);
}
.footer-bottom__meta--wide{width:100%;color:rgba(198,204,206,.75)}

/* ---------- 6 · 响应式 ---------- */
@media (max-width:1080px){
  .footer-shell{grid-template-columns:repeat(3,minmax(0,1fr))}
  .footer-brand{grid-column:1 / -1;max-width:none}
  .grid--split{grid-template-columns:minmax(0,1fr);gap:32px}
  .anchor-rail{position:static;grid-auto-flow:column;grid-auto-columns:max-content;overflow-x:auto;padding-bottom:6px}
}

@media (max-width:900px){
  .grid--3{grid-template-columns:repeat(2,minmax(0,1fr))}
}

@media (max-width:860px){
  html{scroll-padding-top:120px}

  .header-shell{
    grid-template-columns:minmax(0,1fr) auto;
    grid-template-areas:
      "masthead toggle"
      "nav nav"
      "search status";
    padding:14px 18px 0;
    row-gap:12px;
  }
  .masthead{justify-self:start}
  .brand__edition{display:none}
  .nav-toggle{display:inline-flex}
  .site-nav{border-top:1px solid rgba(198,204,206,.28);padding-bottom:0}
  .site-nav__list{display:none;flex-direction:column;gap:6px;justify-content:flex-start;padding-bottom:12px}
  .site-nav[data-open] .site-nav__list{display:flex}
  .site-nav__link{width:100%;justify-content:flex-start;padding:12px 14px;font-size:15px}
  .site-nav__link:hover,.site-nav__link:focus-visible{transform:none}
  .header-search{grid-area:search;justify-self:start;max-width:100%}
  .header-status{grid-area:status}
  .site-header[data-compact] .site-nav__link{padding:10px 14px;font-size:15px}
  .site-header[data-compact] .brand__name{font-size:22px}
}

@media (max-width:720px){
  .grid--2,.grid--3{grid-template-columns:minmax(0,1fr)}
  .footer-shell{grid-template-columns:repeat(2,minmax(0,1fr));padding-top:40px}
  .index-row{grid-template-columns:1fr;gap:6px}
  .index-row__num{text-align:left}
  .section{padding-block:48px}
}

@media (max-width:520px){
  body{font-size:16px}
  .header-shell{padding:12px 14px 0}
  .footer-shell{grid-template-columns:minmax(0,1fr);gap:28px}
  .brand__seal{width:34px;height:34px;font-size:19px}
  .brand__name{font-size:21px}
  .header-search__value{display:none}
  .footer-bottom__inner{padding-inline:14px}
}

@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;
  }
}