/* =========================================================
   万博游艺 · MAX 中文站 共享站点样式 /assets/site.css
   蓝图网格 · 夜间操作手册 · 横向翻页轨道
   ========================================================= */

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

html{
  -webkit-text-size-adjust:100%;
  scroll-behavior:smooth;
  scroll-padding-top:118px;
}

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

ul,ol{margin:0;padding:0;list-style:none;}

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

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

a{color:inherit;}

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

/* ---------- 2. 变量 ---------- */
:root{
  --ink:#08111F;
  --panel:#0F1B2E;
  --panel-2:#0B1524;
  --line:#24364F;
  --cyan:#28E0E8;
  --amber:#FFB547;
  --haze:#6F7396;
  --text:#F2F6FF;
  --muted:#A9B6CC;
  --ok:#45E0A8;
  --warn:#FF7A6B;

  --wrap:1280px;
  --gutter:clamp(16px,4vw,40px);
  --bar-h:70px;

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

  --ease:cubic-bezier(.22,.68,.24,1);
  --glow:0 0 18px rgba(40,224,232,.35);
}

/* ---------- 3. 基础排版 ---------- */
body{
  min-height:100vh;
  font-family:var(--sans);
  font-size:1rem;
  font-weight:400;
  line-height:1.85;
  color:var(--text);
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
  background-color:var(--ink);
  background-image:
    radial-gradient(900px 520px at 82% -6%, rgba(40,224,232,.10), rgba(8,17,31,0) 68%),
    radial-gradient(680px 440px at 4% 2%, rgba(255,181,71,.055), rgba(8,17,31,0) 70%),
    linear-gradient(to right, rgba(36,54,79,.42) 1px, rgba(36,54,79,0) 1px),
    linear-gradient(to bottom, rgba(36,54,79,.30) 1px, rgba(36,54,79,0) 1px);
  background-size:100% 720px, 100% 720px, 88px 88px, 88px 88px;
  background-repeat:no-repeat, no-repeat, repeat, repeat;
}

h1,h2,h3,h4{
  font-weight:800;
  line-height:1.1;
  letter-spacing:.02em;
  font-stretch:condensed;
  color:var(--text);
}

h1{font-size:clamp(2.6rem,6vw,5.6rem);line-height:.98;}
h2{font-size:clamp(1.7rem,3.4vw,2.9rem);line-height:1.06;}
h3{font-size:clamp(1.15rem,1.8vw,1.45rem);line-height:1.25;font-weight:700;}

p{color:var(--muted);}
strong{color:var(--text);font-weight:700;}

code,kbd,samp{font-family:var(--mono);font-size:.92em;color:var(--cyan);}

::selection{background:rgba(40,224,232,.28);color:var(--text);}

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

/* ---------- 4. 通用工具 ---------- */
.wrap{
  width:100%;
  max-width:var(--wrap);
  margin-inline:auto;
  padding-inline:var(--gutter);
}

.mono{
  font-family:var(--mono);
  font-size:.78rem;
  letter-spacing:.16em;
  text-transform:uppercase;
  color:var(--haze);
}

.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:.7em;
  font-family:var(--mono);
  font-size:.72rem;
  letter-spacing:.2em;
  text-transform:uppercase;
  color:var(--cyan);
}

.eyebrow::before{
  content:"";
  width:26px;
  height:1px;
  background:var(--cyan);
}

.rule{
  height:1px;
  width:100%;
  background:linear-gradient(90deg, var(--line), rgba(36,54,79,0));
  border:0;
  margin:0;
}

/* ---------- 5. 跳过链接 ---------- */
.skip-link{
  position:absolute;
  top:8px;
  left:8px;
  z-index:400;
  padding:.62em 1.1em;
  background:var(--cyan);
  color:#04101A;
  font-weight:700;
  font-size:.9rem;
  letter-spacing:.06em;
  text-decoration:none;
  transform:translateY(-180%);
  transition:transform .2s var(--ease);
}

.skip-link:focus,
.skip-link:focus-visible{
  transform:translateY(0);
  outline:2px solid var(--text);
  outline-offset:2px;
}

/* ---------- 6. 按钮 ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:.5em;
  padding:.66em 1.15em;
  border:1px solid transparent;
  border-radius:0;
  font-family:var(--sans);
  font-size:.9rem;
  font-weight:700;
  letter-spacing:.04em;
  line-height:1.2;
  text-decoration:none;
  white-space:nowrap;
  transition:color .18s var(--ease),
             background-color .18s var(--ease),
             border-color .18s var(--ease),
             box-shadow .18s var(--ease),
             transform .18s var(--ease);
}

.btn-primary{
  background:var(--cyan);
  border-color:var(--cyan);
  color:#04101A;
}

.btn-primary:hover{
  box-shadow:var(--glow);
  transform:translateY(-1px);
}

.btn-ghost{
  background:rgba(15,27,46,.55);
  border-color:var(--line);
  color:var(--text);
}

.btn-ghost:hover{
  border-color:var(--cyan);
  color:var(--cyan);
  box-shadow:0 0 14px rgba(40,224,232,.22);
}

.btn-block{
  width:100%;
}

/* ---------- 7. 徽标与状态 ---------- */
.badge{
  display:inline-flex;
  align-items:center;
  gap:.4em;
  padding:.28em .68em;
  border:1px solid currentColor;
  font-family:var(--mono);
  font-size:.68rem;
  font-weight:500;
  letter-spacing:.14em;
  text-transform:uppercase;
  line-height:1.5;
}

.badge--cyan{color:var(--cyan);}
.badge--amber{color:var(--amber);}
.badge--ok{color:var(--ok);}
.badge--warn{color:var(--warn);}

/* ---------- 8. 页头 ---------- */
.site-header{
  position:sticky;
  top:0;
  z-index:90;
  background:linear-gradient(180deg, rgba(8,17,31,.98) 0%, rgba(8,17,31,.92) 100%);
  -webkit-backdrop-filter:blur(12px);
  backdrop-filter:blur(12px);
  border-bottom:1px solid var(--line);
  box-shadow:0 1px 0 rgba(40,224,232,.14);
}

.header-rail{
  display:flex;
  align-items:center;
  gap:14px;
  max-width:var(--wrap);
  margin-inline:auto;
  padding:7px var(--gutter) 0;
  font-family:var(--mono);
  font-size:.64rem;
  letter-spacing:.22em;
  text-transform:uppercase;
  color:var(--haze);
  line-height:1.4;
}

.rail-id{flex:0 0 auto;color:var(--cyan);}

.rail-line{
  flex:1 1 auto;
  height:1px;
  min-width:24px;
  background:linear-gradient(90deg, var(--line) 0%, rgba(36,54,79,.15) 100%);
}

.rail-track{flex:0 0 auto;color:var(--amber);}

.header-bar{
  position:relative;
  display:flex;
  align-items:center;
  gap:clamp(10px,1.6vw,24px);
  max-width:var(--wrap);
  margin-inline:auto;
  padding-inline:var(--gutter);
  min-height:var(--bar-h);
}

/* 品牌 */
.brand{
  display:flex;
  align-items:center;
  gap:.6rem;
  flex:0 0 auto;
  margin-right:auto;
  text-decoration:none;
  color:var(--text);
}

.brand-mark{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  width:38px;
  height:38px;
  flex:0 0 auto;
  border:1px solid var(--cyan);
  background:rgba(40,224,232,.08);
  color:var(--cyan);
  font-family:var(--mono);
  font-size:.74rem;
  font-weight:700;
  letter-spacing:.08em;
  transition:background-color .18s var(--ease), box-shadow .18s var(--ease);
}

.brand:hover .brand-mark{
  background:rgba(40,224,232,.18);
  box-shadow:0 0 16px rgba(40,224,232,.32);
}

.brand-text{
  display:flex;
  flex-direction:column;
  line-height:1.15;
}

.brand-name{
  font-size:1.06rem;
  font-weight:800;
  letter-spacing:.08em;
  color:var(--text);
}

.brand-sub{
  font-family:var(--mono);
  font-size:.64rem;
  letter-spacing:.2em;
  color:var(--haze);
}

/* 主导航 */
.site-nav{
  flex:0 1 auto;
}

.nav-list{
  display:flex;
  align-items:stretch;
  gap:0;
}

.nav-item{
  display:flex;
}

.nav-link{
  position:relative;
  display:flex;
  align-items:center;
  gap:.45em;
  height:var(--bar-h);
  padding:0 clamp(7px,.95vw,13px);
  text-decoration:none;
  font-size:.95rem;
  font-weight:500;
  letter-spacing:.03em;
  color:var(--muted);
  transition:color .18s var(--ease);
}

.nav-link::after{
  content:"";
  position:absolute;
  left:0;
  right:0;
  bottom:-1px;
  height:2px;
  background:var(--cyan);
  transform:scaleX(0);
  transform-origin:left center;
  transition:transform .22s var(--ease);
}

.nav-link:hover{color:var(--text);}
.nav-link:hover::after{transform:scaleX(1);}

.nav-index{
  font-family:var(--mono);
  font-size:.66rem;
  letter-spacing:.14em;
  color:var(--haze);
  transition:color .18s var(--ease);
}

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

.nav-link[aria-current="page"]::after{
  transform:scaleX(1);
}

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

.nav-actions{
  display:none;
}

/* 头部操作区 */
.header-actions{
  display:flex;
  align-items:center;
  gap:10px;
  flex:0 0 auto;
  margin-left:clamp(8px,1.4vw,18px);
}

/* 移动端开关 */
.nav-toggle{
  display:none;
  align-items:center;
  gap:.6em;
  margin-left:auto;
  padding:.5em .8em;
  border:1px solid var(--line);
  background:rgba(15,27,46,.75);
  color:var(--text);
  font-family:var(--mono);
  font-size:.7rem;
  letter-spacing:.16em;
  text-transform:uppercase;
  transition:border-color .18s var(--ease), color .18s var(--ease);
}

.nav-toggle:hover{
  border-color:var(--cyan);
  color:var(--cyan);
}

.nav-toggle-bars{
  display:grid;
  gap:4px;
  width:18px;
}

.nav-toggle-bars span{
  display:block;
  height:2px;
  width:100%;
  background:currentColor;
  transition:transform .2s var(--ease), opacity .2s var(--ease);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bars span:nth-child(1){
  transform:translateY(6px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bars span:nth-child(2){
  opacity:0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bars span:nth-child(3){
  transform:translateY(-6px) rotate(-45deg);
}

/* ---------- 9. 页脚 ---------- */
.site-footer{
  position:relative;
  margin-top:clamp(56px,8vw,110px);
  background:
    linear-gradient(180deg, rgba(11,21,36,0) 0%, rgba(15,27,46,.5) 18%, var(--panel-2) 100%);
  border-top:1px solid var(--line);
  color:var(--muted);
}

.site-footer::before{
  content:"";
  position:absolute;
  left:0;
  right:0;
  top:-1px;
  height:2px;
  background:linear-gradient(90deg,
    var(--cyan) 0 16%,
    rgba(40,224,232,0) 16% 18%,
    var(--amber) 18% 27%,
    var(--line) 27% 100%);
}

.footer-frame{
  width:100%;
  max-width:var(--wrap);
  margin-inline:auto;
  padding-inline:var(--gutter);
}

.footer-top{
  display:grid;
  grid-template-columns:minmax(200px,1.05fr) minmax(0,1.9fr) minmax(230px,1.15fr);
  gap:clamp(24px,3.2vw,56px);
  padding:clamp(36px,5vw,64px) 0 clamp(26px,3.4vw,44px);
  border-bottom:1px solid var(--line);
}

.footer-logo{
  display:inline-block;
  font-size:1.2rem;
  font-weight:800;
  letter-spacing:.1em;
  color:var(--text);
  text-decoration:none;
  transition:color .18s var(--ease);
}

.footer-logo:hover{color:var(--cyan);}

.footer-brandline{
  margin-top:.5em;
  font-family:var(--mono);
  font-size:.68rem;
  letter-spacing:.2em;
  text-transform:uppercase;
  color:var(--haze);
}

.footer-slogan{
  position:relative;
  margin-top:1.1em;
  padding-top:.85em;
  font-size:clamp(1.3rem,2vw,1.6rem);
  font-weight:800;
  letter-spacing:.06em;
  line-height:1.2;
  color:var(--text);
}

.footer-slogan::before{
  content:"";
  position:absolute;
  top:0;
  left:0;
  width:44px;
  height:2px;
  background:var(--cyan);
}

.footer-groups{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  gap:clamp(16px,2vw,32px);
}

.footer-group-title{
  margin-bottom:.95em;
  font-family:var(--mono);
  font-size:.68rem;
  font-weight:500;
  letter-spacing:.2em;
  text-transform:uppercase;
  color:var(--amber);
}

.footer-links{
  display:grid;
  gap:.6em;
}

.footer-links a{
  display:inline-block;
  font-size:.94rem;
  color:var(--muted);
  text-decoration:none;
  transition:color .16s var(--ease), transform .16s var(--ease);
}

.footer-links a:hover{
  color:var(--cyan);
  transform:translateX(3px);
}

.footer-contact{
  display:grid;
  gap:.95em;
  align-content:start;
}

.footer-contact-item{
  display:grid;
  gap:.15em;
}

.footer-contact-label{
  font-family:var(--mono);
  font-size:.64rem;
  letter-spacing:.18em;
  text-transform:uppercase;
  color:var(--haze);
}

.footer-contact-value{
  font-size:.94rem;
  line-height:1.5;
  color:var(--text);
  word-break:break-word;
}

.footer-note{
  margin-top:.3em;
  padding-top:.9em;
  border-top:1px solid rgba(36,54,79,.7);
  font-size:.82rem;
  line-height:1.75;
  color:var(--haze);
}

.footer-bottom{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:10px 26px;
  padding:16px 0 26px;
}

.footer-legal,
.footer-copy,
.footer-meta{
  font-family:var(--mono);
  font-size:.7rem;
  letter-spacing:.12em;
  color:var(--haze);
  line-height:1.6;
}

.footer-legal{color:var(--muted);}

.footer-meta{
  margin-left:auto;
  text-transform:uppercase;
}

/* ---------- 10. 章节 / 布局骨架 ---------- */
.section{
  padding-block:clamp(48px,7vw,96px);
}

.section--tight{
  padding-block:clamp(30px,4vw,56px);
}

.section--panel{
  background:var(--panel);
  border-block:1px solid var(--line);
}

.section-head{
  display:grid;
  gap:.75rem;
  margin-bottom:clamp(24px,3.2vw,44px);
  max-width:62ch;
}

.section-title{
  font-size:clamp(1.7rem,3.4vw,2.9rem);
  line-height:1.06;
}

.section-lede{
  font-size:1rem;
  line-height:1.85;
  color:var(--muted);
}

.grid{
  display:grid;
  gap:clamp(16px,2.4vw,32px);
}

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

/* ---------- 11. 公告横条 ---------- */
.notice-bar{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:.6em 1.15em;
  padding:1em clamp(16px,2.4vw,28px);
  border:1px solid rgba(255,181,71,.28);
  border-left:3px solid var(--amber);
  background:linear-gradient(90deg, rgba(255,181,71,.16) 0%, rgba(255,181,71,.04) 60%, rgba(255,181,71,0) 100%);
  font-size:.94rem;
  line-height:1.7;
  color:var(--text);
}

.notice-bar-tag{
  font-family:var(--mono);
  font-size:.68rem;
  font-weight:700;
  letter-spacing:.18em;
  text-transform:uppercase;
  color:var(--amber);
}

.notice-bar p{color:var(--text);}

.notice-bar a{
  color:var(--amber);
  text-decoration:none;
  border-bottom:1px solid rgba(255,181,71,.45);
}

.notice-bar a:hover{border-bottom-color:var(--amber);}

/* ---------- 12. 面包屑 ---------- */
.breadcrumbs{
  padding-top:clamp(20px,3vw,32px);
}

.breadcrumbs-list{
  display:flex;
  flex-wrap:wrap;
  gap:.55em;
  font-family:var(--mono);
  font-size:.7rem;
  letter-spacing:.13em;
  text-transform:uppercase;
  color:var(--haze);
}

.breadcrumbs-list li{
  display:flex;
  align-items:center;
  gap:.55em;
}

.breadcrumbs-list li + li::before{
  content:"/";
  color:var(--line);
}

.breadcrumbs a{
  color:var(--muted);
  text-decoration:none;
  transition:color .16s var(--ease);
}

.breadcrumbs a:hover{color:var(--cyan);}

.breadcrumbs [aria-current="page"]{color:var(--cyan);}

/* ---------- 13. 可展开内容组 ---------- */
.accordion{
  border-top:1px solid var(--line);
}

.accordion-item{
  border-bottom:1px solid var(--line);
}

.accordion-trigger{
  display:flex;
  align-items:center;
  gap:.9em;
  width:100%;
  padding:1.05em 0;
  text-align:left;
  font-family:var(--sans);
  font-size:1.02rem;
  font-weight:700;
  line-height:1.5;
  color:var(--text);
  transition:color .18s var(--ease);
}

.accordion-trigger:hover{color:var(--cyan);}

.accordion-index{
  flex:0 0 auto;
  font-family:var(--mono);
  font-size:.7rem;
  font-weight:500;
  letter-spacing:.14em;
  color:var(--haze);
}

.accordion-trigger[aria-expanded="true"] .accordion-index{color:var(--cyan);}

.accordion-mark{
  position:relative;
  flex:0 0 auto;
  width:14px;
  height:14px;
  margin-left:auto;
  color:var(--cyan);
}

.accordion-mark::before,
.accordion-mark::after{
  content:"";
  position:absolute;
  left:0;
  right:0;
  top:50%;
  height:1px;
  background:currentColor;
  transform:translateY(-50%);
}

.accordion-mark::after{
  transition:transform .22s var(--ease), opacity .18s var(--ease);
}

.accordion-trigger[aria-expanded="true"] .accordion-mark::after{
  transform:translateY(-50%) rotate(0deg);
  opacity:0;
}

.accordion-trigger[aria-expanded="false"] .accordion-mark::after{
  transform:translateY(-50%) rotate(90deg);
  opacity:1;
}

.accordion-panel{
  padding:0 0 1.3em 2.1em;
  font-size:.96rem;
  line-height:1.85;
  color:var(--muted);
}

.accordion-panel[hidden]{display:none;}

/* ---------- 14. 图片容器基础规则 ---------- */
.media-frame{
  position:relative;
  display:block;
  overflow:hidden;
  isolation:isolate;
  background:var(--panel);
  border:1px solid var(--line);
}

.media-frame::after{
  content:"";
  position:absolute;
  inset:0;
  z-index:2;
  pointer-events:none;
  background:linear-gradient(122deg,
    rgba(40,224,232,.16) 0%,
    rgba(40,224,232,0) 44%,
    rgba(255,181,71,.12) 100%);
}

.media-frame::before{
  content:"";
  position:absolute;
  inset:8px;
  z-index:1;
  pointer-events:none;
  border-top:1px solid rgba(40,224,232,.22);
  border-left:1px solid rgba(40,224,232,.22);
}

.media-frame img,
.media-frame picture,
.media-frame video,
.media-frame svg{
  display:block;
  width:100%;
  height:100%;
  object-fit:cover;
}

.media-frame--16x9{aspect-ratio:16 / 9;}
.media-frame--3x2{aspect-ratio:3 / 2;}
.media-frame--4x5{aspect-ratio:4 / 5;}
.media-frame--square{aspect-ratio:1 / 1;}

/* ---------- 15. 滚动增强组件 ---------- */
.reveal{
  opacity:0;
  transform:translateX(-14px);
  transition:opacity .4s var(--ease), transform .4s var(--ease);
  will-change:opacity, transform;
}

.reveal.is-in{
  opacity:1;
  transform:none;
}

.scroll-progress{
  position:fixed;
  top:0;
  left:0;
  width:100%;
  height:2px;
  z-index:300;
  transform:scaleX(0);
  transform-origin:left center;
  background:linear-gradient(90deg, var(--cyan) 0%, var(--amber) 100%);
  pointer-events:none;
}

.to-top{
  position:fixed;
  right:18px;
  bottom:18px;
  z-index:200;
  display:grid;
  place-items:center;
  width:44px;
  height:44px;
  border:1px solid var(--line);
  border-radius:0;
  background:rgba(15,27,46,.94);
  color:var(--cyan);
  font-family:var(--mono);
  font-size:1rem;
  line-height:1;
  opacity:0;
  transform:translateY(10px);
  pointer-events:none;
  transition:opacity .22s var(--ease),
             transform .22s var(--ease),
             border-color .16s var(--ease),
             box-shadow .16s var(--ease);
}

.to-top[data-visible]{
  opacity:1;
  transform:none;
  pointer-events:auto;
}

.to-top:hover,
.to-top:focus-visible{
  border-color:var(--cyan);
  box-shadow:var(--glow);
}

/* ---------- 16. 响应式 ---------- */
@media (max-width:1120px){
  .header-actions{display:none;}

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

  .site-nav{
    position:absolute;
    left:0;
    right:0;
    top:100%;
    z-index:95;
    display:none;
    max-height:calc(100vh - 110px);
    overflow-y:auto;
    padding:10px var(--gutter) 24px;
    background:linear-gradient(180deg, var(--panel) 0%, #0A1424 100%);
    border-top:1px solid var(--line);
    border-bottom:1px solid var(--line);
    box-shadow:0 26px 48px rgba(0,0,0,.55);
  }

  .site-nav[data-open]{display:block;}

  .nav-list{
    flex-direction:column;
    gap:0;
  }

  .nav-item{
    border-bottom:1px solid rgba(36,54,79,.6);
  }

  .nav-link{
    width:100%;
    height:auto;
    justify-content:flex-start;
    gap:.8em;
    padding:15px 4px;
    font-size:1rem;
  }

  .nav-link::after{display:none;}

  .nav-link[aria-current="page"]{
    color:var(--cyan);
    padding-left:10px;
    box-shadow:inset 2px 0 0 var(--cyan);
  }

  .nav-actions{
    display:grid;
    gap:10px;
    margin-top:16px;
  }

  .footer-top{
    grid-template-columns:minmax(0,1fr) minmax(0,1.6fr);
  }

  .footer-contact{
    grid-column:1 / -1;
    grid-template-columns:repeat(auto-fit,minmax(220px,1fr));
    padding-top:clamp(18px,2.4vw,28px);
    border-top:1px solid rgba(36,54,79,.7);
  }

  .footer-note{
    grid-column:1 / -1;
    border-top:0;
    padding-top:0;
  }
}

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

  .footer-top{
    grid-template-columns:minmax(0,1fr);
    gap:clamp(22px,3vw,34px);
  }

  .footer-groups{
    grid-template-columns:repeat(2,minmax(0,1fr));
    gap:20px 24px;
  }

  .footer-meta{
    margin-left:0;
    width:100%;
  }
}

@media (max-width:640px){
  :root{--bar-h:62px;}

  html{scroll-padding-top:104px;}

  body{
    background-size:100% 620px, 100% 620px, 64px 64px, 64px 64px;
  }

  .header-rail{font-size:.58rem;letter-spacing:.18em;}

  .rail-track{display:none;}

  .brand-mark{width:34px;height:34px;font-size:.68rem;}

  .brand-name{font-size:1rem;}

  .brand-sub{font-size:.58rem;letter-spacing:.16em;}

  .accordion-panel{padding-left:0;}

  .to-top{right:12px;bottom:12px;width:40px;height:40px;}

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

  .footer-bottom{gap:8px;}

  .footer-meta{font-size:.66rem;}
}

/* ---------- 17. 动效偏好 ---------- */
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto;}

  *,
  *::before,
  *::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }

  .reveal{
    opacity:1;
    transform:none;
  }

  .scroll-progress{display:none;}

  .btn-primary:hover,
  .footer-links a:hover{transform:none;}
}