/* =========================================================
   优博看台 /assets/site.css
   高原夜场看台手册：深翠绿 · 砂纸米 · 火把橙 · 天空青
   ========================================================= */

/* ---------- 1. Reset ---------- */
*,
*::before,
*::after{box-sizing:border-box;}

html{
  -webkit-text-size-adjust:100%;
  text-size-adjust:100%;
  scroll-behavior:smooth;
}

body,
h1,h2,h3,h4,h5,h6,
p,figure,blockquote,dl,dd,ol,ul{margin:0;}

ol,ul{padding:0;}

img,svg,video{display:block;max-width:100%;height:auto;}

button{font:inherit;color:inherit;background:none;border:0;}

input,select,textarea{font:inherit;color:inherit;}

/* ---------- 2. Tokens ---------- */
:root{
  --grass:#0E3B2E;
  --ink:#08251F;
  --concrete:#A7A9A3;
  --paper:#F4EFE3;
  --flame:#E86A2A;
  --flame-deep:#C4531C;
  --sky:#2B8C9E;
  --sky-deep:#1D6B7A;
  --sky-light:#5AB7C6;
  --bright:#3F7A4F;
  --sand:#D8CBB4;
  --line:#5D625B;
  --alert:#B6462F;

  --font-display:'Arial Narrow','PingFang SC','Microsoft YaHei',sans-serif;
  --font-serif:'Noto Serif SC','Songti SC',SimSun,serif;
  --font-body:'PingFang SC','Microsoft YaHei','Noto Sans SC',sans-serif;
  --font-mono:'JetBrains Mono','SFMono-Regular',Consolas,'Courier New',monospace;

  --shell:1320px;
  --rail:248px;
  --pad:clamp(16px,3.2vw,44px);
  --gap:clamp(16px,2.2vw,30px);

  --fs-72:clamp(38px,6.4vw,72px);
  --fs-56:clamp(32px,4.8vw,56px);
  --fs-40:clamp(26px,3.6vw,40px);
  --fs-28:clamp(21px,2.4vw,28px);
  --fs-20:20px;
  --fs-16:16px;
  --fs-14:14px;
  --fs-12:12px;

  --hair:1px solid rgba(93,98,91,.42);
  --hair-strong:1px solid var(--line);
  --hair-dark:1px solid rgba(244,239,227,.16);
  --hair-dark-strong:1px solid rgba(244,239,227,.3);
}

/* ---------- 3. 基础排版 ---------- */
body{
  background:var(--paper);
  color:var(--ink);
  font-family:var(--font-body);
  font-size:var(--fs-16);
  line-height:1.75;
  letter-spacing:.004em;
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
}

h1,h2,h3,h4{
  font-weight:700;
  line-height:1.14;
  letter-spacing:-.012em;
  text-wrap:balance;
}

h1{
  font-family:var(--font-display);
  font-size:var(--fs-72);
  line-height:.94;
  letter-spacing:-.032em;
  font-stretch:condensed;
}

h2{
  font-family:var(--font-display);
  font-size:var(--fs-40);
  line-height:1.02;
  letter-spacing:-.022em;
}

h3{
  font-size:var(--fs-20);
  line-height:1.32;
}

h4{
  font-size:var(--fs-16);
  line-height:1.38;
}

p{margin-bottom:1.05em;}
p:last-child{margin-bottom:0;}

a{
  color:var(--sky-deep);
  text-decoration:none;
  transition:color .2s ease;
}

a:hover{color:var(--flame);}

strong{font-weight:700;}

hr,
.rule{
  height:0;
  margin:0;
  border:0;
  border-top:var(--hair-strong);
}

.mono,
.num{
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  letter-spacing:.06em;
}

.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:10px;
  margin:0 0 14px;
  font-family:var(--font-mono);
  font-size:var(--fs-12);
  letter-spacing:.22em;
  text-transform:uppercase;
  color:var(--bright);
}

.eyebrow::before{
  content:"";
  width:22px;
  height:1px;
  background:var(--flame);
}

.prose{
  max-width:74ch;
  font-size:var(--fs-16);
  line-height:1.78;
}

.prose p{margin-bottom:1.05em;}

.prose h2,
.prose h3{
  margin:1.6em 0 .6em;
}

.prose ul,
.prose ol{
  margin:0 0 1.05em;
  padding-left:1.35em;
  list-style:square;
}

.prose a{
  border-bottom:1px solid currentColor;
  padding-bottom:1px;
}

/* ---------- 4. 焦点与无障碍 ---------- */
:focus-visible{
  outline:2px solid var(--flame);
  outline-offset:3px;
}

.site-header :focus-visible,
.site-footer :focus-visible{
  outline:2px solid var(--sand);
  outline-offset:3px;
}

.skip-link{
  position:fixed;
  top:-72px;
  left:var(--pad);
  z-index:400;
  display:inline-block;
  padding:10px 18px;
  background:var(--flame);
  color:#FFF6EE;
  font-family:var(--font-mono);
  font-size:var(--fs-12);
  letter-spacing:.14em;
  border:1px solid #FFF6EE;
  transition:top .2s ease;
}

.skip-link:focus,
.skip-link:focus-visible{
  top:10px;
  color:#FFF6EE;
}

.sr-only{
  position:absolute;
  width:1px;
  height:1px;
  padding:0;
  margin:-1px;
  overflow:hidden;
  clip:rect(0 0 0 0);
  white-space:nowrap;
  border:0;
}

/* ---------- 5. 容器与网格 ---------- */
.container{
  width:100%;
  max-width:var(--shell);
  margin-inline:auto;
  padding-inline:var(--pad);
}

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

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

.grid--2{grid-template-columns:repeat(2,minmax(0,1fr));}

.grid--3{grid-template-columns:repeat(3,minmax(0,1fr));}

.grid--rail{
  grid-template-columns:var(--rail) minmax(0,1fr);
  align-items:start;
}

.grid--rail > .grid__full{grid-column:1 / -1;}

.grid--span-full{grid-column:1 / -1;}

.grid--span-main{grid-column:2 / -1;}

/* ---------- 6. 头部命令栏 ---------- */
.site-header{
  position:sticky;
  top:0;
  z-index:200;
  background:var(--grass);
  color:var(--paper);
  border-bottom:var(--hair-dark);
  box-shadow:0 1px 0 rgba(8,37,31,.9);
}

.site-header__bar{
  display:flex;
  align-items:center;
  gap:clamp(10px,2vw,26px);
  width:100%;
  max-width:var(--shell);
  margin-inline:auto;
  padding:10px var(--pad) 9px;
}

.brand{
  display:inline-flex;
  align-items:center;
  gap:12px;
  min-width:0;
  color:var(--paper);
  text-decoration:none;
}

.brand:hover{color:var(--paper);}

.brand__mark{
  display:grid;
  place-items:center;
  flex:none;
  width:34px;
  height:34px;
  background:var(--flame);
  color:#FFF6EE;
  font-family:var(--font-mono);
  font-size:13px;
  font-weight:700;
  letter-spacing:.04em;
  line-height:1;
}

.brand__text{
  display:flex;
  flex-direction:column;
  gap:1px;
  min-width:0;
}

.brand__name{
  font-family:var(--font-display);
  font-size:20px;
  font-weight:700;
  letter-spacing:.16em;
  line-height:1.1;
  color:var(--paper);
}

.brand__tagline{
  font-family:var(--font-mono);
  font-size:10px;
  letter-spacing:.16em;
  line-height:1.2;
  color:rgba(244,239,227,.58);
  white-space:nowrap;
}

.header__status{
  display:inline-flex;
  align-items:center;
  gap:8px;
  margin:0 0 0 auto;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.14em;
  line-height:1;
  color:rgba(244,239,227,.72);
  white-space:nowrap;
}

.header__status::before{
  content:"";
  flex:none;
  width:6px;
  height:6px;
  background:var(--flame);
  box-shadow:0 0 0 3px rgba(232,106,42,.16);
}

.nav-toggle{
  display:none;
  align-items:center;
  gap:10px;
  margin-left:auto;
  padding:8px 12px;
  border:1px solid rgba(244,239,227,.34);
  color:var(--paper);
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.18em;
  line-height:1;
  cursor:pointer;
  transition:background-color .2s ease,border-color .2s ease;
}

.nav-toggle:hover{
  background:rgba(244,239,227,.08);
  border-color:rgba(244,239,227,.55);
}

.nav-toggle[aria-expanded="true"]{
  background:rgba(232,106,42,.2);
  border-color:rgba(232,106,42,.75);
}

.nav-toggle__label{
  display:inline-block;
  min-width:3.4em;
  text-align:left;
}

.nav-toggle__bars{
  position:relative;
  display:block;
  flex:none;
  width:16px;
  height:2px;
  background:var(--paper);
}

.nav-toggle__bars::before,
.nav-toggle__bars::after{
  content:"";
  position:absolute;
  left:0;
  width:16px;
  height:2px;
  background:var(--paper);
}

.nav-toggle__bars::before{top:-5px;}
.nav-toggle__bars::after{top:5px;}

.site-nav{
  background:rgba(8,37,31,.45);
  border-top:var(--hair-dark);
}

.nav-list{
  display:flex;
  align-items:stretch;
  gap:0;
  width:100%;
  max-width:var(--shell);
  margin-inline:auto;
  padding:0 var(--pad);
  list-style:none;
  overflow-x:auto;
  scrollbar-width:none;
}

.nav-list::-webkit-scrollbar{display:none;}

.nav-item{
  display:flex;
  flex:none;
}

.nav-link{
  display:inline-flex;
  align-items:baseline;
  gap:8px;
  padding:11px clamp(10px,1.5vw,22px) 10px;
  border-bottom:2px solid transparent;
  color:rgba(244,239,227,.76);
  font-size:var(--fs-14);
  letter-spacing:.02em;
  line-height:1.3;
  white-space:nowrap;
  text-decoration:none;
  transition:color .2s ease,background-color .2s ease,border-color .2s ease,transform .2s ease;
}

.nav-link__index{
  font-family:var(--font-mono);
  font-size:10px;
  letter-spacing:.1em;
  color:rgba(244,239,227,.42);
  transition:color .2s ease;
}

.nav-link__label{display:inline-block;}

.nav-link:hover{
  color:var(--paper);
  background:rgba(244,239,227,.07);
}

.nav-link:hover .nav-link__index{color:var(--flame);}

.nav-link[aria-current="page"]{
  color:#FFF9EE;
  border-bottom-color:var(--flame);
  background:rgba(244,239,227,.09);
  transform:translateY(-1px);
}

.nav-link[aria-current="page"] .nav-link__index{color:var(--flame);}

.scroll-bar{
  height:2px;
  background:rgba(244,239,227,.1);
  overflow:hidden;
}

.scroll-bar__fill{
  display:block;
  width:0;
  height:100%;
  background:linear-gradient(90deg,var(--flame),#F09155);
}

/* ---------- 7. 页脚档案层 ---------- */
.site-footer{
  margin-top:clamp(40px,6vw,84px);
  padding:clamp(34px,4.6vw,62px) 0 0;
  background:var(--ink);
  color:rgba(244,239,227,.82);
  border-top:3px solid var(--grass);
}

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

.footer__top{
  display:grid;
  grid-template-columns:1.35fr 1fr .95fr 1.3fr;
  gap:var(--gap);
  padding-bottom:clamp(24px,3.4vw,42px);
  border-bottom:var(--hair-dark);
}

.footer__brand{min-width:0;}

.footer__wordmark{
  margin:0 0 12px;
  font-family:var(--font-display);
  font-size:clamp(26px,3vw,34px);
  font-weight:700;
  line-height:1;
  letter-spacing:.1em;
  color:var(--paper);
}

.footer__note{
  margin:0 0 14px;
  max-width:34ch;
  font-size:var(--fs-14);
  line-height:1.7;
  color:rgba(244,239,227,.6);
}

.footer__stamp{
  margin:0;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.16em;
  color:rgba(167,169,163,.9);
}

.footer__col{min-width:0;}

.footer__col-title{
  margin:0 0 14px;
  font-family:var(--font-mono);
  font-size:11px;
  font-weight:400;
  letter-spacing:.2em;
  line-height:1;
  color:var(--sand);
  text-transform:uppercase;
}

.footer__list{
  display:grid;
  gap:9px;
  list-style:none;
  margin:0;
  padding:0;
}

.footer__link{
  display:inline-block;
  color:rgba(244,239,227,.8);
  font-size:var(--fs-14);
  line-height:1.5;
  text-decoration:none;
  border-bottom:1px solid transparent;
  transition:color .2s ease,border-color .2s ease;
}

.footer__link:hover{
  color:var(--flame);
  border-bottom-color:var(--flame);
}

.footer__contact{
  display:grid;
  gap:11px;
  margin:0;
}

.footer__contact-row{
  margin:0;
  display:grid;
  gap:2px;
  font-size:13px;
  line-height:1.55;
  color:rgba(244,239,227,.78);
  word-break:break-word;
}

.footer__contact-key{
  font-family:var(--font-mono);
  font-size:10px;
  letter-spacing:.2em;
  color:var(--concrete);
}

.footer__legal{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:clamp(12px,2.2vw,28px);
  padding:18px 0;
  border-bottom:var(--hair-dark);
}

.footer__legal-link{
  color:rgba(244,239,227,.7);
  font-size:13px;
  line-height:1.6;
  text-decoration:none;
  border-bottom:1px solid transparent;
  transition:color .2s ease,border-color .2s ease;
}

.footer__legal-link:hover{
  color:var(--sky-light);
  border-bottom-color:var(--sky-light);
}

.footer__beta{
  margin-left:auto;
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:5px 11px;
  border:1px dashed rgba(167,169,163,.42);
  background:rgba(244,239,227,.03);
  color:rgba(167,169,163,.82);
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.1em;
  line-height:1.4;
  text-decoration:none;
  transition:color .2s ease,border-color .2s ease,background-color .2s ease;
}

.footer__beta::after{
  content:"↗";
  font-size:10px;
  opacity:.7;
}

.footer__beta:hover{
  color:var(--sand);
  border-color:rgba(216,203,180,.75);
  background:rgba(244,239,227,.06);
}

.footer__meta{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:10px;
  padding:16px 0 clamp(22px,3vw,32px);
}

.footer__meta-text{
  margin:0;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.1em;
  line-height:1.6;
  color:rgba(244,239,227,.45);
}

/* ---------- 8. 通用按钮 ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:10px;
  padding:12px 22px;
  border:1px solid transparent;
  font-family:var(--font-body);
  font-size:15px;
  font-weight:600;
  letter-spacing:.04em;
  line-height:1.3;
  text-decoration:none;
  cursor:pointer;
  transition:background-color .2s ease,color .2s ease,border-color .2s ease;
}

.btn:hover{text-decoration:none;}

.btn--primary{
  background:var(--flame);
  border-color:var(--flame);
  color:#FFF7EF;
}

.btn--primary:hover{
  background:var(--flame-deep);
  border-color:var(--flame-deep);
  color:#FFF7EF;
}

.btn--ghost{
  background:transparent;
  border-color:var(--grass);
  color:var(--grass);
}

.btn--ghost:hover{
  background:var(--grass);
  border-color:var(--grass);
  color:var(--paper);
}

.btn--on-dark{
  background:transparent;
  border-color:rgba(244,239,227,.45);
  color:var(--paper);
}

.btn--on-dark:hover{
  background:var(--paper);
  border-color:var(--paper);
  color:var(--grass);
}

/* ---------- 9. 面包屑与章节 ---------- */
.breadcrumb{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:8px;
  margin:0 0 20px;
  padding:0;
  list-style:none;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.14em;
  color:var(--line);
}

.breadcrumb__item{display:inline-flex;align-items:center;gap:8px;}

.breadcrumb__link{
  color:var(--grass);
  text-decoration:none;
  border-bottom:1px solid rgba(14,59,46,.28);
  padding-bottom:1px;
}

.breadcrumb__link:hover{
  color:var(--flame);
  border-bottom-color:var(--flame);
}

.breadcrumb__sep{
  color:var(--concrete);
  font-size:10px;
}

.breadcrumb__current{
  color:var(--ink);
  letter-spacing:.1em;
}

.section{
  padding:clamp(30px,4vw,56px) 0;
  border-top:var(--hair);
}

.section__head{
  display:flex;
  flex-wrap:wrap;
  align-items:baseline;
  gap:10px clamp(14px,2vw,28px);
  margin-bottom:clamp(16px,2.2vw,28px);
}

.section__title{
  margin:0;
  font-family:var(--font-display);
  font-size:var(--fs-28);
  line-height:1.06;
  letter-spacing:-.018em;
}

.section__note{
  margin:0;
  margin-left:auto;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.14em;
  line-height:1.6;
  color:var(--line);
}

/* ---------- 10. 标签、状态、资料卡 ---------- */
.chip{
  display:inline-flex;
  align-items:center;
  padding:4px 10px;
  background:var(--sand);
  color:var(--grass);
  font-size:var(--fs-12);
  font-weight:600;
  letter-spacing:.06em;
  line-height:1.5;
  border:1px solid rgba(93,98,91,.3);
}

.status-pill{
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:4px 11px;
  border:1px solid rgba(43,140,158,.55);
  background:rgba(43,140,158,.08);
  color:var(--sky-deep);
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.12em;
  line-height:1.5;
}

.status-pill::before{
  content:"";
  flex:none;
  width:5px;
  height:5px;
  background:var(--sky);
}

.card{
  padding:clamp(16px,2vw,24px);
  background:#FBF7EE;
  border:var(--hair);
  color:var(--ink);
}

.card:hover{
  border-color:var(--grass);
}

/* ---------- 11. 图片容器（页面阶段放置素材） ---------- */
.media-frame{
  position:relative;
  display:block;
  width:100%;
  aspect-ratio:16 / 9;
  overflow:hidden;
  background:var(--grass);
  border:1px solid rgba(93,98,91,.4);
}

.media-frame > img{
  width:100%;
  height:100%;
  object-fit:cover;
  object-position:center;
}

.media-frame::after{
  content:"";
  position:absolute;
  inset:0;
  pointer-events:none;
  background:
    repeating-linear-gradient(90deg,transparent 0 47px,rgba(244,239,227,.05) 47px 48px);
  opacity:.6;
}

.media-frame > img + ::after,
.media-frame > img ~ .media-frame__badge{z-index:2;}

.media-frame--wide{aspect-ratio:21 / 9;}
.media-frame--tall{aspect-ratio:4 / 5;}
.media-frame--square{aspect-ratio:1 / 1;}

.media-frame__badge{
  position:absolute;
  left:12px;
  bottom:12px;
  z-index:3;
  padding:3px 9px;
  background:var(--flame);
  color:#FFF7EF;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.08em;
  line-height:1.5;
}

.figure-caption{
  margin:10px 0 0;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.1em;
  line-height:1.6;
  color:var(--line);
}

/* ---------- 12. 滚动显现（由 JS 加 .js-reveal 启用） ---------- */
.js-reveal [data-reveal]{
  opacity:0;
  transform:translateY(16px);
  transition:opacity .34s ease,transform .34s cubic-bezier(.22,.61,.36,1);
  will-change:opacity,transform;
}

.js-reveal [data-reveal].is-visible{
  opacity:1;
  transform:none;
}

@keyframes navDrop{
  from{opacity:0;transform:translateY(-6px);}
  to{opacity:1;transform:none;}
}

/* ---------- 13. 平板 ---------- */
@media (max-width:1080px){
  :root{--rail:210px;}

  .footer__top{grid-template-columns:repeat(2,minmax(0,1fr));}
  .footer__brand{grid-column:1 / -1;}
}

@media (max-width:900px){
  .header__status{display:none;}

  .nav-toggle{display:inline-flex;}

  .site-nav{
    display:none;
    border-top:var(--hair-dark);
  }

  .site-nav[data-open]{
    display:block;
    max-height:calc(100vh - 116px);
    overflow-y:auto;
    animation:navDrop .2s ease both;
  }

  .nav-list{
    flex-direction:column;
    padding:0;
    max-width:none;
    overflow:visible;
  }

  .nav-item{width:100%;}

  .nav-link{
    width:100%;
    padding:13px var(--pad);
    border-bottom:var(--hair-dark);
    border-bottom-width:1px;
    border-left:3px solid transparent;
    font-size:15px;
  }

  .nav-link[aria-current="page"]{
    border-bottom:var(--hair-dark);
    border-left-color:var(--flame);
    background:rgba(244,239,227,.08);
    transform:none;
  }

  .grid--rail{grid-template-columns:minmax(0,1fr);}
  .grid--span-main{grid-column:1 / -1;}
  .grid--3{grid-template-columns:repeat(2,minmax(0,1fr));}
}

/* ---------- 14. 手机 ---------- */
@media (max-width:640px){
  .site-header__bar{padding:9px var(--pad) 8px;gap:10px;}

  .brand__mark{width:30px;height:30px;font-size:12px;}

  .brand__name{font-size:17px;letter-spacing:.12em;}

  .brand__tagline{font-size:9px;letter-spacing:.12em;}

  .nav-toggle{padding:7px 10px;font-size:10px;letter-spacing:.14em;}

  .footer__top{grid-template-columns:minmax(0,1fr);gap:22px;}

  .footer__legal{flex-direction:column;align-items:flex-start;gap:12px;}

  .footer__beta{margin-left:0;}

  .footer__meta{flex-direction:column;align-items:flex-start;}

  .grid--2,
  .grid--3{grid-template-columns:minmax(0,1fr);}

  .section__note{margin-left:0;}
}

/* ---------- 15. Reduced motion ---------- */
@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;
  }

  .js-reveal [data-reveal]{
    opacity:1 !important;
    transform:none !important;
  }

  .nav-link[aria-current="page"]{transform:none;}
}