:root{
  --ink:#1c1726;
  --ink2:#251d35;
  --deep:#150f1f;
  --violet:#6514ff;
  --magenta:#bf00ff;
  --paper:#f4efff;
  --dim:#b9aee0;
  --line:#3b2f57;
  --bar:78px;
  --pad:clamp(16px,4vw,44px);
}

*,*::before,*::after{box-sizing:border-box}

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

body{
  margin:0;
  background:var(--ink);
  color:var(--paper);
  font-family:"Space Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  font-size:17px;
  line-height:1.65;
  padding-bottom:calc(var(--bar) + 40px);
  overflow-x:hidden;
}

body::before{
  content:"";
  position:fixed;
  inset:-20% -20% -20% -20%;
  z-index:0;
  pointer-events:none;
  opacity:.55;
  background-image:repeating-linear-gradient(115deg,rgba(101,20,255,.20) 0 2px,transparent 2px 92px);
  background-size:300% 300%;
  animation:drift 26s linear infinite;
}

@keyframes drift{
  from{background-position:0 0}
  to{background-position:480px 0}
}

.top-anchor{display:block;height:0}

a{color:inherit}
:focus-visible{outline:3px solid var(--magenta);outline-offset:3px}

/* ---------- 底部固定导航 ---------- */
.nav{
  position:fixed;
  left:0;
  right:0;
  bottom:0;
  z-index:60;
  display:flex;
  align-items:center;
  gap:10px;
  padding:10px var(--pad);
  background:rgba(21,15,31,.96);
  border-top:3px solid var(--violet);
  box-shadow:0 -18px 40px rgba(10,6,18,.6);
}

.brand{
  display:inline-flex;
  align-items:center;
  gap:10px;
  flex:none;
  min-height:44px;
  padding:6px 4px 6px 0;
  color:var(--paper);
  text-decoration:none;
  font-weight:700;
  font-size:17px;
  letter-spacing:-.02em;
}

.brand-mark{
  width:12px;
  height:12px;
  background:var(--magenta);
  transform:skewX(-18deg);
  box-shadow:9px 0 0 var(--violet);
}

.drawer{
  display:flex;
  align-items:center;
  gap:8px;
  flex:1 1 auto;
  min-width:0;
}

.drawer > summary{
  list-style:none;
  cursor:pointer;
  display:inline-flex;
  align-items:center;
  gap:7px;
  flex:none;
  min-height:44px;
  padding:8px 10px;
  border:2px solid var(--line);
  color:var(--dim);
  font-size:16px;
  font-weight:700;
}

.drawer > summary::-webkit-details-marker{display:none}

.sum-bar{
  width:14px;
  height:8px;
  border-top:2px solid var(--magenta);
  border-bottom:2px solid var(--magenta);
}

.drawer > menu{
  display:flex;
  gap:6px;
  margin:0;
  padding:0;
  min-width:0;
  list-style:none;
  overflow-x:auto;
  scrollbar-width:none;
}

.drawer > menu::-webkit-scrollbar{display:none}
.drawer > menu li{flex:none}

.drawer > menu a{
  display:inline-flex;
  align-items:center;
  gap:8px;
  min-height:44px;
  padding:8px 12px;
  color:var(--paper);
  text-decoration:none;
  font-size:16px;
  border-bottom:3px solid transparent;
  transition:background .24s ease,color .24s ease,border-color .24s ease;
}

.drawer > menu a::before{
  content:"";
  width:7px;
  height:7px;
  flex:none;
  background:var(--violet);
}

.drawer > menu li:nth-child(2n) a::before{background:var(--magenta)}

.drawer > menu a:hover,
.drawer > menu a:focus-visible{
  background:var(--ink2);
  color:#fff;
  border-bottom-color:var(--magenta);
}

.cta{
  flex:none;
  display:inline-flex;
  align-items:center;
  min-height:44px;
  padding:8px 16px;
  background:var(--magenta);
  color:var(--deep);
  font-weight:700;
  font-size:16px;
  text-decoration:none;
  border:2px solid var(--deep);
  box-shadow:4px 4px 0 var(--violet);
  transition:background .24s ease,color .24s ease,box-shadow .24s ease,transform .24s ease;
}

.cta:hover,
.cta:focus-visible{
  background:var(--violet);
  color:#fff;
  box-shadow:4px 4px 0 var(--magenta);
  transform:translate(-2px,-2px);
}

/* ---------- 头部大色块 ---------- */
.main{position:relative;z-index:1}

.hero{
  position:relative;
  overflow:hidden;
  display:flex;
  align-items:flex-end;
  min-height:45vh;
  padding:clamp(26px,6vw,58px) var(--pad) clamp(46px,9vw,84px);
  background:linear-gradient(118deg,#1c1726 0%,#241a38 52%,#2d1245 100%);
  clip-path:polygon(0 0,100% 0,100% 100%,0 91%);
  border-bottom:1px solid var(--line);
}

.hero::before{
  content:"69";
  position:absolute;
  z-index:1;
  right:-.06em;
  top:-.34em;
  font-size:clamp(140px,34vw,330px);
  font-weight:700;
  line-height:1;
  letter-spacing:-.09em;
  color:transparent;
  -webkit-text-stroke:2px rgba(191,0,255,.55);
  pointer-events:none;
  animation:float 9s ease-in-out infinite alternate;
}

@keyframes float{
  from{transform:translateY(8px)}
  to{transform:translateY(-14px)}
}

.hero-art{
  position:absolute;
  inset:0;
  z-index:0;
  margin:0;
  overflow:hidden;
}

.hero-art img{
  display:block;
  width:100%;
  height:100%;
  object-fit:cover;
  opacity:.6;
  filter:grayscale(1) contrast(1.25);
  transform:translateY(var(--par,0px)) scale(1.1);
  will-change:transform;
}

.hero-art::after{
  content:"";
  position:absolute;
  inset:0;
  background:linear-gradient(102deg,var(--violet),var(--magenta));
  mix-blend-mode:color;
  opacity:.85;
}

.hero-copy{
  position:relative;
  z-index:2;
  max-width:36ch;
}

.hero h1{
  margin:0;
  font-size:clamp(30px,6.4vw,58px);
  line-height:1.1;
  letter-spacing:-.035em;
  text-shadow:0 3px 26px rgba(12,7,20,.92);
}

.hero-sub{
  margin:14px 0 0;
  max-width:44ch;
  font-size:17px;
  color:var(--paper);
  opacity:.86;
  text-shadow:0 2px 14px rgba(12,7,20,.9);
}

/* ---------- 主栅格：左栏目录 + 正文 ---------- */
.board{
  display:grid;
  grid-template-columns:250px minmax(0,1fr);
  align-items:start;
  gap:clamp(24px,4vw,56px);
  max-width:1200px;
  margin:0 auto;
  padding:clamp(32px,6vw,56px) var(--pad) 48px;
}

.rail{
  position:sticky;
  top:24px;
  padding-top:14px;
  border-top:4px solid var(--magenta);
  background:linear-gradient(180deg,rgba(101,20,255,.14),transparent);
}

.rail h2{
  margin:0 0 12px;
  font-size:18px;
  letter-spacing:.14em;
}

.rail h2 > span{
  display:inline-block;
  position:relative;
  padding-left:15px;
}

.rail h2 > span::before{
  content:"";
  position:absolute;
  left:0;
  top:.55em;
  width:8px;
  height:8px;
  background:var(--violet);
}

.rail ol{
  list-style:none;
  counter-reset:rail;
  margin:0;
  padding:0;
}

.rail li{counter-increment:rail}

.rail li a{
  display:flex;
  align-items:center;
  gap:10px;
  min-height:44px;
  padding:6px 0;
  color:var(--dim);
  font-size:16px;
  text-decoration:none;
  border-bottom:1px dashed var(--line);
  transition:color .22s ease,padding-left .22s ease;
}

.rail li a::before{
  content:"0" counter(rail);
  flex:none;
  font-size:14px;
  letter-spacing:.06em;
  color:var(--magenta);
}

.rail li a:hover,
.rail li a:focus-visible{color:#fff;padding-left:6px}

.rail-top{
  display:inline-flex;
  align-items:center;
  min-height:44px;
  margin-top:12px;
  color:var(--paper);
  font-size:16px;
  text-decoration:none;
  border-bottom:3px solid var(--violet);
}

/* ---------- 正文区（内容由程序注入） ---------- */
.body-content{min-width:0}

.body-content > section{
  position:relative;
  margin:0 0 clamp(32px,5vw,56px);
  padding:clamp(20px,3.4vw,36px);
  background:var(--ink2);
  border:2px solid var(--line);
  border-bottom:6px solid var(--violet);
  scroll-margin-top:20px;
  scroll-margin-bottom:calc(var(--bar) + 28px);
}

.body-content > section:nth-child(2n){border-bottom-color:var(--magenta)}
.body-content > section:last-child{margin-bottom:0}

.body-content h2{
  margin:.1em 0 .65em;
  font-size:clamp(22px,3.4vw,34px);
  line-height:1.22;
  letter-spacing:-.025em;
}

.body-content h3{
  margin:1.5em 0 .55em;
  font-size:clamp(18px,2.4vw,22px);
  line-height:1.3;
}

.body-content h2 > span,
.body-content h3 > span{
  display:inline-block;
  position:relative;
  padding-left:20px;
}

.body-content h2 > span::before,
.body-content h3 > span::before{
  content:"";
  position:absolute;
  left:0;
  top:.2em;
  bottom:.2em;
  width:9px;
  background:var(--magenta);
  transform:skewX(-14deg);
}

.body-content p{margin:0 0 1em;max-width:72ch}
.body-content ul,
.body-content ol{margin:0 0 1.1em;padding-left:1.3em}
.body-content li{margin:.35em 0}
.body-content strong{color:#fff}
.body-content a{color:#dcc0ff;text-decoration:none;border-bottom:1px solid var(--violet)}
.body-content a:hover{color:#fff;border-bottom-color:var(--magenta)}
.body-content img{display:block;max-width:100%;height:auto;filter:grayscale(.2)}
.body-content figure{margin:0 0 1em}
.body-content blockquote{
  margin:1.1em 0;
  padding:12px 16px;
  background:rgba(101,20,255,.14);
  border-left:6px solid var(--violet);
}
.body-content table{width:100%;border-collapse:collapse;display:block;overflow-x:auto}
.body-content th,
.body-content td{padding:8px 10px;border:1px solid var(--line);text-align:left}

/* ---------- 页脚 ---------- */
.foot{
  position:relative;
  z-index:1;
  padding:clamp(28px,5vw,48px) var(--pad) 20px;
  background:var(--deep);
  border-top:4px solid var(--violet);
}

.foot-grid{
  display:grid;
  grid-template-columns:1.2fr 1fr;
  gap:clamp(24px,4vw,48px);
  max-width:1200px;
  margin:0 auto;
}

.foot-logo{
  margin:0 0 10px;
  font-size:clamp(20px,3vw,26px);
  font-weight:700;
  letter-spacing:-.03em;
}

.foot address{
  font-style:normal;
  color:var(--dim);
  font-size:16px;
}

.foot-links h2{
  margin:0 0 10px;
  font-size:16px;
  letter-spacing:.16em;
}

.foot-links h2 > span{
  display:inline-block;
  position:relative;
  padding-left:15px;
}

.foot-links h2 > span::before{
  content:"";
  position:absolute;
  left:0;
  top:.5em;
  width:8px;
  height:8px;
  background:var(--magenta);
}

.foot-links ul{
  display:flex;
  flex-wrap:wrap;
  gap:4px 18px;
  margin:0;
  padding:0;
  list-style:none;
}

.foot-links a{
  display:inline-flex;
  align-items:center;
  min-height:44px;
  color:var(--dim);
  font-size:16px;
  text-decoration:none;
  border-bottom:2px solid transparent;
}

.foot-links a:hover,
.foot-links a:focus-visible{color:#fff;border-bottom-color:var(--magenta)}

.foot-copy{
  max-width:1200px;
  margin:clamp(20px,3vw,32px) auto 0;
  padding-top:14px;
  border-top:1px solid var(--line);
  color:#9c90bf;
  font-size:16px;
}

/* ---------- 断点 ---------- */
@media (max-width:880px){
  .board{grid-template-columns:1fr;gap:26px}
  .rail{position:static}
  .rail ol{display:flex;flex-wrap:wrap;gap:2px 16px}
  .rail li a{border-bottom:none;padding:6px 0}
  .foot-grid{grid-template-columns:1fr}
}

@media (max-width:640px){
  :root{--bar:72px}
  body{padding-bottom:120px}
  .hero{min-height:44vh;clip-path:polygon(0 0,100% 0,100% 100%,0 95%)}
  .hero::before{font-size:clamp(120px,42vw,200px);top:-.22em}
  .brand{font-size:16px;gap:8px}
  .drawer > summary{padding:8px}
  .cta{padding:8px 10px;box-shadow:3px 3px 0 var(--violet)}
  .body-content > section{padding:18px 16px}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  body::before{animation:none}
  .hero::before{animation:none}
  .hero-art img{transform:none}
  .cta:hover{transform:none}
  .rail li a{transition:none}
}

button[aria-expanded]{min-width:44px;min-height:44px}