/* ============================================================
   开云看台 · 共享样式 /assets/site.css
   夜间看台灯光系统：曜石黑 + 深墨绿底，信号橙行动锚点，冷青数据状态
   ============================================================ */

/* ---------- 1. 设计令牌 ---------- */
:root{
  color-scheme: dark;

  --ink:#080C0B;
  --forest:#0D2A22;
  --stand:#163D32;
  --teal:#123F39;
  --signal:#FF6A2A;
  --ember:#FFB27A;
  --cold:#46D8C7;
  --mist:#F1F5F2;
  --steel:#8EA59D;
  --paper:#FFFFFF;

  --line: rgba(142,165,157,.22);
  --line-soft: rgba(142,165,157,.14);
  --line-strong: rgba(142,165,157,.42);

  --font-display: "Helvetica Neue","Arial Narrow","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  --font-body: "PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-mono: ui-monospace,"SFMono-Regular",Menlo,Consolas,"Courier New",monospace;

  --shell: 1180px;
  --gutter: clamp(18px, 4vw, 44px);

  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 28px;
  --radius-xl: 44px;
  --pill: 999px;

  --shadow: 0 26px 60px -34px rgba(0,0,0,.95);
  --ease: cubic-bezier(.22,.7,.28,1);
}

/* ---------- 2. Reset ---------- */
*,*::before,*::after{ box-sizing:border-box; }
html{ -webkit-text-size-adjust:100%; scroll-behavior:smooth; }
body,h1,h2,h3,h4,h5,h6,p,ul,ol,li,dl,dt,dd,figure,blockquote{ margin:0; padding:0; }
ul,ol{ list-style:none; }
img,svg,picture,video{ display:block; max-width:100%; height:auto; }
button{ font:inherit; color:inherit; background:none; border:0; }
table{ border-collapse:collapse; width:100%; }

/* ---------- 3. 基础排版（中文正文） ---------- */
body{
  background: var(--ink);
  color: var(--mist);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.75;
  letter-spacing: .01em;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
h1,h2,h3,h4{
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.06;
  letter-spacing: -.02em;
  text-wrap: balance;
}
h1{ font-size: clamp(2.4rem, 6vw, 5rem); }
h2{ font-size: clamp(1.75rem, 3.4vw, 2.75rem); }
h3{ font-size: clamp(1.15rem, 1.7vw, 1.45rem); line-height:1.25; }
h4{ font-size: 1rem; line-height:1.35; letter-spacing:.04em; }
p{ max-width: 68ch; }
a{
  color: var(--cold);
  text-decoration: none;
  transition: color .18s var(--ease), border-color .18s var(--ease);
}
a:hover{ color: var(--ember); }
strong,b{ color: var(--paper); font-weight: 700; }
small{ font-size: .8125rem; }
hr{ border:0; }

:focus-visible{
  outline: 2px solid var(--cold);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ---------- 4. 布局基础 ---------- */
.shell{
  width:100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.section{ padding-block: clamp(48px, 7vw, 104px); }
.section--tight{ padding-block: clamp(28px, 4vw, 56px); }
.measure{ max-width: 68ch; }
.rule{ height:1px; background: var(--line); border:0; margin:0; }
.visually-hidden{
  position:absolute !important;
  width:1px; height:1px; margin:-1px; padding:0;
  overflow:hidden; clip: rect(0 0 0 0); clip-path: inset(50%);
  white-space: nowrap; border:0;
}
.grid{ display:grid; gap: clamp(16px, 2vw, 28px); }
.grid--2{ grid-template-columns: repeat(2, minmax(0,1fr)); }
.grid--3{ grid-template-columns: repeat(3, minmax(0,1fr)); }
.grid--auto{ grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }

/* ---------- 5. 图片容器基础（页面阶段放占位或实图） ---------- */
.img-frame{
  position: relative;
  isolation: isolate;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  border-radius: var(--radius-lg);
  border: 1px solid var(--line);
  background: linear-gradient(155deg, var(--stand), var(--ink) 72%);
}
.img-frame > img,
.img-frame > picture > img{
  width:100%; height:100%;
  object-fit: cover;
  display:block;
}
.img-frame::after{
  content:"";
  position:absolute; inset:0; z-index:1; pointer-events:none;
  background: linear-gradient(180deg, rgba(8,12,11,0) 38%, rgba(8,12,11,.78) 100%);
}
.img-frame--wide{ aspect-ratio: 21 / 9; }
.img-frame--tall{ aspect-ratio: 3 / 4; }
.img-frame--square{ aspect-ratio: 1 / 1; }
.img-frame--tilt{ border-radius: var(--radius-lg) var(--radius-lg) var(--radius-lg) 88px; }
.img-frame__placeholder{
  position:absolute; inset:0; z-index:0;
  background-image:
    repeating-linear-gradient(90deg, rgba(70,216,199,.10) 0 1px, transparent 1px 72px),
    repeating-linear-gradient(0deg, rgba(70,216,199,.10) 0 1px, transparent 1px 72px),
    radial-gradient(120% 90% at 18% 0%, rgba(255,106,42,.26), transparent 62%),
    linear-gradient(155deg, var(--stand), var(--ink));
}
.img-frame__caption{
  position:absolute; left:0; right:0; bottom:0; z-index:2;
  display:flex; justify-content:space-between; align-items:flex-end; gap:14px;
  padding: 16px 20px;
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--mist);
}

/* ---------- 6. 按钮与标签 ---------- */
.btn{
  display:inline-flex; align-items:center; justify-content:center; gap:10px;
  min-height: 48px;
  padding: 0 26px;
  border: 1px solid transparent;
  border-radius: var(--pill);
  font-family: var(--font-body);
  font-size: .9375rem;
  font-weight: 700;
  letter-spacing: .02em;
  line-height: 1;
  cursor: pointer;
  text-align: center;
  transition: background .18s var(--ease), color .18s var(--ease),
              border-color .18s var(--ease), transform .18s var(--ease);
}
.btn--primary{ background: var(--signal); color: var(--ink); }
.btn--primary:hover{ background: var(--ember); color: var(--ink); transform: translateY(-2px); }
.btn--ghost{ background: transparent; color: var(--mist); border-color: var(--line-strong); }
.btn--ghost:hover{ color: var(--cold); border-color: var(--cold); transform: translateY(-2px); }
.btn--quiet{ background: rgba(70,216,199,.10); color: var(--cold); border-color: rgba(70,216,199,.30); }
.btn--quiet:hover{ background: rgba(70,216,199,.18); color: var(--mist); }
.btn--link{
  min-height: 44px; padding: 0;
  border-radius: 0;
  border-bottom: 1px solid rgba(70,216,199,.42);
  color: var(--cold);
}
.btn--link:hover{ color: var(--ember); border-color: var(--ember); }
.btn--sm{ min-height: 40px; padding: 0 18px; font-size: .875rem; }
.btn:active{ transform: translateY(0); }

.tag{
  display:inline-flex; align-items:center; gap:8px;
  min-height: 28px; padding: 0 12px;
  border-radius: var(--pill);
  border: 1px solid rgba(70,216,199,.32);
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--cold);
  white-space: nowrap;
}
.tag--signal{ border-color: rgba(255,106,42,.5); color: var(--ember); }
.tag--muted{ border-color: var(--line-strong); color: var(--steel); }

/* ---------- 7. 索引、章节、卡片 ---------- */
.eyebrow{
  display:block;
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .24em;
  text-transform: uppercase;
  color: var(--cold);
}
.mono{
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: .04em;
}
.chapter{
  display:flex; align-items:baseline; gap:14px;
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--cold);
}
.chapter__num{ font-size: 1.05rem; letter-spacing: .06em; color: var(--signal); }
.chapter__line{ flex:1; height:1px; background: var(--line); align-self:center; }

.card{
  display:flex; flex-direction:column; gap:12px;
  padding: clamp(20px, 2.4vw, 32px);
  border-radius: var(--radius-lg);
  border: 1px solid var(--line);
  background: linear-gradient(165deg, var(--stand) 0%, var(--teal) 100%);
  transition: border-color .2s var(--ease), transform .2s var(--ease), box-shadow .2s var(--ease);
}
.card:hover{
  border-color: rgba(70,216,199,.48);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}
.card__index{
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .22em;
  color: var(--signal);
}
.card__title{
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.25rem;
  line-height: 1.2;
  letter-spacing: -.01em;
  color: var(--mist);
}
.card__text{ color: var(--steel); font-size: .9375rem; line-height: 1.7; }
.card__foot{ margin-top: auto; padding-top: 8px; }

/* ---------- 8. 面包屑与长文 ---------- */
.breadcrumb{
  display:flex; flex-wrap:wrap; align-items:center; gap:8px;
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .14em;
  color: var(--steel);
}
.breadcrumb a{ color: var(--steel); }
.breadcrumb a:hover{ color: var(--cold); }
.breadcrumb__sep{ color: rgba(142,165,157,.5); }
.breadcrumb [aria-current="page"]{ color: var(--mist); }

.prose{ max-width: 68ch; }
.prose > * + *{ margin-top: 1.1em; }
.prose h2{ margin-top: 2em; }
.prose h3{ margin-top: 1.6em; }
.prose ul{ display:grid; gap:.5em; padding-left: 1.1em; }
.prose ul li{ position: relative; }
.prose ul li::before{
  content:"";
  position:absolute; left:-1.1em; top:.8em;
  width: 8px; height: 1px;
  background: var(--signal);
}
.prose a{
  color: var(--cold);
  border-bottom: 1px solid rgba(70,216,199,.42);
}
.prose a:hover{ color: var(--ember); border-color: var(--ember); }

/* ---------- 9. 头部：索引导轨 + 居中刊头 + 灯轨导航 ---------- */
.skip-link{
  position: absolute;
  left: 16px; top: -80px;
  z-index: 200;
  padding: 12px 22px;
  border-radius: var(--pill);
  background: var(--signal);
  color: var(--ink);
  font-weight: 700;
  font-size: .875rem;
  transition: top .2s var(--ease);
}
.skip-link:focus{ top: 12px; color: var(--ink); }
.skip-link:focus-visible{ outline-color: var(--ink); }

.site-header{
  position: sticky;
  top: 0;
  z-index: 80;
  color: var(--mist);
  background: linear-gradient(180deg, rgba(8,12,11,.98) 0%, rgba(13,42,34,.96) 100%);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(12px);
}

.site-header__rail{
  border-bottom: 1px solid var(--line-soft);
  background: rgba(18,63,57,.45);
}
.rail__inner{
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
  min-height: 34px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--steel);
}
.rail__note{
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0;
  max-width: none;
  white-space: nowrap;
  color: var(--steel);
}
.rail__dot{
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--cold);
  box-shadow: 0 0 0 3px rgba(70,216,199,.16);
  flex: none;
}
.rail__list{
  display: flex;
  align-items: center;
  gap: 4px;
  overflow-x: auto;
  scrollbar-width: none;
}
.rail__list::-webkit-scrollbar{ display: none; }
.rail__link{
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  padding: 0 11px;
  border-radius: var(--pill);
  color: var(--steel);
  letter-spacing: .1em;
  white-space: nowrap;
  transition: color .18s var(--ease), background .18s var(--ease);
}
.rail__link:hover{ color: var(--cold); background: rgba(70,216,199,.10); }

.masthead{ position: relative; }
.masthead__inner{
  max-width: var(--shell);
  margin-inline: auto;
  padding: 14px var(--gutter);
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 16px;
}
.masthead__meta{
  margin: 0;
  max-width: none;
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--steel);
}
.masthead__meta b{ color: var(--signal); font-weight: 600; }

.brand{
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  justify-self: center;
  color: var(--mist);
  transition: color .18s var(--ease);
}
.brand:hover{ color: var(--mist); }
.brand__zh{
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.45rem, 2.4vw, 1.95rem);
  line-height: 1;
  letter-spacing: .16em;
  padding-left: .16em;
  transition: color .18s var(--ease);
}
.brand__en{
  font-family: var(--font-mono);
  font-size: .625rem;
  letter-spacing: .42em;
  padding-left: .42em;
  color: var(--steel);
}
.brand:hover .brand__zh{ color: var(--ember); }

.masthead__actions{
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 10px;
}

.nav-toggle{
  display: none;
  align-items: center;
  justify-content: center;
  gap: 9px;
  min-height: 44px;
  min-width: 44px;
  padding: 0 16px;
  border-radius: var(--pill);
  border: 1px solid var(--line-strong);
  background: rgba(22,61,50,.6);
  color: var(--mist);
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .18em;
  cursor: pointer;
  transition: border-color .18s var(--ease), color .18s var(--ease), background .18s var(--ease);
}
.nav-toggle:hover{ border-color: var(--cold); color: var(--cold); }
.nav-toggle__bars{
  position: relative;
  width: 14px; height: 2px;
  border-radius: 2px;
  background: currentColor;
  box-shadow: 0 -4px 0 currentColor, 0 4px 0 currentColor;
  flex: none;
}
.nav-toggle[aria-expanded="true"]{
  border-color: var(--signal);
  color: var(--signal);
  background: rgba(255,106,42,.12);
}
.nav-toggle__text{ line-height: 1; }

.site-nav{
  border-top: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(22,61,50,.52), rgba(13,42,34,.12));
}
.site-nav__list{
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
  display: flex;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  gap: 2px;
}
.site-nav__item{ display: block; }
.site-nav__link{
  display: inline-flex;
  align-items: center;
  min-height: 50px;
  padding: 0 15px;
  border-radius: var(--pill);
  font-size: .9375rem;
  color: var(--steel);
  transition: color .2s var(--ease), background .2s var(--ease);
}
.site-nav__link:hover{ color: var(--mist); background: rgba(70,216,199,.10); }
.site-nav__link[aria-current="page"]{
  background: var(--signal);
  color: var(--ink);
  font-weight: 700;
}
.site-nav__link[aria-current="page"]:hover{ background: var(--ember); color: var(--ink); }

/* ---------- 10. 页脚：灯带 + 三栏 + 法务条 ---------- */
.site-footer{
  position: relative;
  background: var(--ink);
  color: var(--mist);
  border-top: 1px solid var(--line);
}
.site-footer::before{
  content:"";
  display: block;
  height: 3px;
  background: linear-gradient(90deg, var(--signal) 0%, var(--ember) 26%, var(--cold) 58%, rgba(8,12,11,0) 100%);
  opacity: .9;
}
.site-footer__inner{
  max-width: var(--shell);
  margin-inline: auto;
  padding: clamp(44px, 6vw, 80px) var(--gutter) clamp(32px, 5vw, 56px);
  display: grid;
  grid-template-columns: minmax(210px, 1fr) minmax(0, 1.35fr) minmax(240px, 1fr);
  gap: clamp(28px, 4vw, 56px);
  align-items: start;
}
.footer-brand .brand{ align-items: flex-start; justify-self: start; }
.footer-brand__line{
  margin-top: 18px;
  max-width: 24ch;
  font-size: .9375rem;
  line-height: 1.7;
  color: var(--steel);
}

.footer-map{
  display: grid;
  grid-template-columns: repeat(3, minmax(0,1fr));
  gap: clamp(18px, 3vw, 34px);
}
.footer-map__title{
  font-family: var(--font-mono);
  font-size: .6875rem;
  font-weight: 600;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--cold);
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 12px;
}
.footer-map__list{ display: flex; flex-direction: column; gap: 2px; }
.footer-map__link{
  display: inline-flex;
  align-items: center;
  min-height: 36px;
  font-size: .9375rem;
  color: var(--steel);
  transition: color .18s var(--ease), padding-left .18s var(--ease);
}
.footer-map__link:hover{ color: var(--mist); padding-left: 6px; }

.footer-contact__label{
  margin: 0 0 14px;
  max-width: none;
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--cold);
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}
.footer-contact__list{ display: grid; gap: 12px; }
.footer-contact__row{ display: grid; gap: 2px; }
.footer-contact__key{
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .18em;
  color: var(--steel);
}
.footer-contact__val{
  color: var(--mist);
  font-size: .9375rem;
  line-height: 1.6;
  word-break: break-word;
}
.footer-contact__note{
  margin-top: 14px;
  font-size: .8125rem;
  line-height: 1.7;
  color: var(--steel);
}

.footer-base{
  border-top: 1px solid var(--line);
  background: rgba(13,42,34,.42);
}
.footer-base__inner{
  max-width: var(--shell);
  margin-inline: auto;
  padding: 18px var(--gutter);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 24px;
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .08em;
  color: var(--steel);
}
.footer-base__copy,
.footer-base__icp{ margin: 0; max-width: none; color: var(--steel); }
.footer-base__legal{
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-left: auto;
}
.footer-base__link{
  display: inline-flex;
  align-items: center;
  min-height: 32px;
  color: var(--steel);
  transition: color .18s var(--ease);
}
.footer-base__link:hover{ color: var(--cold); }

/* ---------- 11. 阅读进度与进场 ---------- */
.scroll-meter{
  position: fixed;
  top: 0; left: 0; right: 0;
  height: 2px;
  z-index: 120;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--signal), var(--ember) 42%, var(--cold));
  pointer-events: none;
}
[data-reveal]{
  opacity: 0;
  transform: translateY(16px);
  transition: opacity .55s var(--ease), transform .55s var(--ease);
}
[data-reveal].is-visible{ opacity: 1; transform: none; }

/* ---------- 12. 响应式 ---------- */
@media (max-width: 1080px){
  .grid--3{ grid-template-columns: repeat(2, minmax(0,1fr)); }
  .site-footer__inner{ grid-template-columns: minmax(0,1fr) minmax(0,1fr); }
  .footer-brand{ grid-column: 1 / -1; }
}

@media (max-width: 900px){
  .site-header__rail{ display: none; }
  .masthead__inner{
    grid-template-columns: 1fr auto;
    padding: 12px var(--gutter);
    gap: 12px;
  }
  .masthead__meta{ display: none; }
  .brand{ justify-self: start; align-items: flex-start; }
  .masthead__actions{ justify-self: end; }
  .nav-toggle{ display: inline-flex; }

  .site-nav{
    display: none;
    border-top: 1px solid var(--line);
    background: linear-gradient(180deg, rgba(22,61,50,.72), rgba(13,42,34,.94));
  }
  .site-nav[data-open]{ display: block; }
  .site-nav__list{
    flex-direction: column;
    align-items: stretch;
    flex-wrap: nowrap;
    gap: 4px;
    padding: 10px var(--gutter) 20px;
  }
  .site-nav__item{ width: 100%; }
  .site-nav__link{
    justify-content: flex-start;
    width: 100%;
    min-height: 50px;
    padding: 0 16px;
    border-radius: var(--radius-sm);
    font-size: 1rem;
    color: var(--mist);
    background: rgba(22,61,50,.55);
  }
  .site-nav__link:hover{ background: rgba(70,216,199,.14); }
  .site-nav__link[aria-current="page"]{ background: var(--signal); color: var(--ink); }
}

@media (max-width: 720px){
  .grid--2,
  .grid--3,
  .grid--auto{ grid-template-columns: 1fr; }
  .site-footer__inner{ grid-template-columns: 1fr; }
  .footer-map{ grid-template-columns: repeat(2, minmax(0,1fr)); }
  .footer-base__inner{ flex-direction: column; align-items: flex-start; gap: 6px; }
  .footer-base__legal{ margin-left: 0; }
}

@media (max-width: 560px){
  .brand__zh{ font-size: 1.35rem; }
  .brand__en{ letter-spacing: .3em; font-size: .5625rem; }
  .masthead__actions .btn--primary{ min-height: 44px; padding: 0 16px; font-size: .875rem; }
  .nav-toggle{ padding: 0 12px; }
  .img-frame__caption{ flex-direction: column; align-items: flex-start; gap: 4px; }
}

/* ---------- 13. 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;
    scroll-behavior: auto !important;
  }
  [data-reveal]{ opacity: 1; transform: none; }
  .scroll-meter{ display: none; }
  .btn:hover,
  .card:hover,
  .footer-map__link:hover{ transform: none; padding-left: 0; }
}