:root{
  --v:#6514ff;
  --p:#bf00ff;
  --ink:#1c1726;
  --bg:#f4efff;
  --card:rgba(255,255,255,.68);
  --line:rgba(28,23,38,.12);
  --r:18px;
  --pad:clamp(16px,3vw,44px);
  --side:250px;
  --gap:48px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  margin:0;
  font-family:'Noto Sans SC',system-ui,-apple-system,'PingFang SC','Microsoft YaHei',sans-serif;
  font-size:17px;
  line-height:1.8;
  font-weight:400;
  color:var(--ink);
  background:var(--bg);
  overflow-x:hidden;
}
body::before{
  content:'';
  position:fixed;
  inset:-12% -12% auto -12%;
  height:86vh;
  z-index:0;
  pointer-events:none;
  background:
    radial-gradient(36% 44% at 14% 8%,rgba(191,0,255,.30),transparent 70%),
    radial-gradient(44% 50% at 86% 2%,rgba(101,20,255,.28),transparent 72%);
  animation:drift 20s ease-in-out infinite alternate;
}
@keyframes drift{
  from{transform:translate3d(0,0,0) scale(1)}
  to{transform:translate3d(0,5%,0) scale(1.1)}
}
img{max-width:100%;height:auto}
a{color:var(--v)}

/* ============ 左侧固定竖排导航 ============ */
.side{
  position:fixed;
  top:0;
  left:0;
  bottom:0;
  width:var(--side);
  z-index:20;
  display:flex;
  flex-direction:column;
  gap:16px;
  padding:30px 22px 26px;
  background:linear-gradient(165deg,#1c1726 0%,#271142 58%,#3a0d5e 100%);
  color:#f3ecff;
  overflow-y:auto;
  overflow-x:hidden;
}
.side::after{
  content:'';
  position:absolute;
  top:0;
  right:0;
  width:2px;
  height:100%;
  background:linear-gradient(180deg,var(--v),var(--p) 40%,transparent);
}
.brand{
  display:block;
  padding-left:12px;
  border-left:4px solid var(--p);
  font-size:24px;
  font-weight:700;
  line-height:1.25;
  letter-spacing:.01em;
  color:#fff;
  text-decoration:none;
  transition:border-color .22s ease;
}
.brand:hover{border-left-color:#fff}
.menu-btn{
  display:none;
  font:inherit;
  font-size:16px;
  min-height:44px;
  padding:0 18px;
  border-radius:999px;
  border:1px solid rgba(255,255,255,.34);
  background:transparent;
  color:#fff;
  cursor:pointer;
}
.side nav ul{
  list-style:none;
  margin:0;
  padding:0;
  display:flex;
  flex-direction:column;
  gap:4px;
}
.side nav li:nth-child(3){
  padding-bottom:10px;
  margin-bottom:6px;
  border-bottom:1px dashed rgba(255,255,255,.16);
}
.side nav a{
  display:flex;
  align-items:center;
  gap:10px;
  min-height:44px;
  padding:10px 12px;
  border-radius:12px;
  border:1px solid transparent;
  color:#d6c9f4;
  font-size:16px;
  line-height:1.4;
  text-decoration:none;
  transition:background .22s ease,color .22s ease,transform .22s ease,border-color .22s ease;
}
.side nav .idx{
  flex:0 0 auto;
  font-size:12px;
  font-weight:500;
  letter-spacing:.12em;
  color:var(--p);
}
.side nav a:hover,
.side nav a.on{
  background:rgba(255,255,255,.10);
  border-color:rgba(191,0,255,.66);
  color:#fff;
  transform:translateX(4px);
}
.side nav a:hover .idx,
.side nav a.on .idx{color:#e6b9ff}
.contact{
  margin-top:auto;
  display:flex;
  align-items:center;
  justify-content:center;
  min-height:46px;
  border-radius:999px;
  background:linear-gradient(100deg,var(--v),var(--p));
  color:#fff;
  font-size:16px;
  font-weight:500;
  text-decoration:none;
  transition:transform .22s ease,filter .22s ease;
}
.contact:hover{transform:translateY(-2px);filter:brightness(1.12)}

/* ============ 主区 ============ */
main{
  position:relative;
  z-index:1;
  margin-left:var(--side);
  max-width:1360px;
  padding:0 var(--pad);
}

/* -------- hero -------- */
.hero{
  position:relative;
  z-index:1;
  min-height:70vh;
  margin:0 calc(-1 * var(--pad));
  padding:70px var(--pad) 104px;
  display:grid;
  grid-template-columns:minmax(0,1.05fr) minmax(0,.95fr);
  grid-gap:var(--gap);
  align-items:end;
  background:#1c1726;
  color:#fff;
  overflow:hidden;
  border-radius:0 0 34px 34px;
}
.hero::before{
  content:'';
  position:absolute;
  top:-30%;
  left:-14%;
  width:62%;
  height:120%;
  background:linear-gradient(140deg,rgba(101,20,255,.62),rgba(191,0,255,.18) 70%,transparent);
  transform:rotate(-9deg);
  pointer-events:none;
}
.hero::after{
  content:'';
  position:absolute;
  left:0;
  right:0;
  bottom:0;
  height:76px;
  background:linear-gradient(90deg,var(--v),var(--p));
  transform:skewY(-3deg);
  transform-origin:left bottom;
  pointer-events:none;
}
.hero-fig{
  position:relative;
  margin:0;
  align-self:stretch;
  min-height:290px;
  border-radius:var(--r);
  overflow:hidden;
  background:
    linear-gradient(150deg,rgba(101,20,255,.7),rgba(191,0,255,.34) 60%,rgba(28,23,38,.9));
  border:1px solid rgba(255,255,255,.2);
}
.hero-fig img{
  display:block;
  width:100%;
  height:100%;
  object-fit:cover;
  filter:grayscale(.18) contrast(1.08);
}
.hero-txt{
  position:relative;
  z-index:2;
  text-align:right;
  padding-bottom:34px;
}
.hero-txt .kick{
  display:inline-block;
  font-size:14px;
  font-weight:500;
  letter-spacing:.26em;
  color:#d9b2ff;
  margin-bottom:16px;
}
.hero h1{
  margin:0 0 26px;
  font-size:clamp(30px,4.1vw,56px);
  line-height:1.16;
  font-weight:700;
  letter-spacing:-.012em;
  color:#fff;
}
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  min-height:48px;
  padding:0 32px;
  border-radius:999px;
  background:#fff;
  color:var(--ink);
  font-size:16px;
  font-weight:700;
  text-decoration:none;
  transition:background .22s ease,color .22s ease,transform .22s ease;
}
.btn:hover{background:var(--p);color:#fff;transform:translateY(-3px)}

/* -------- 双栏 -------- */
.split{
  display:grid;
  grid-template-columns:minmax(0,1fr) 262px;
  grid-gap:var(--gap);
  align-items:start;
  padding:56px 0 76px;
}

/* -------- 正文 -------- */
.entry{
  min-width:0;
  display:grid;
  grid-gap:var(--gap);
}
.entry > div{
  position:relative;
  scroll-margin-top:26px;
  padding:clamp(22px,3vw,44px);
  border-radius:var(--r);
  background:var(--card);
  border:1px solid rgba(101,20,255,.15);
  box-shadow:0 22px 46px -34px rgba(28,23,38,.55);
  -webkit-backdrop-filter:blur(14px);
  backdrop-filter:blur(14px);
}
.entry > div:nth-child(even){border-left:6px solid var(--p)}
.entry > div:nth-child(odd){border-right:6px solid rgba(101,20,255,.5)}
.entry small{
  display:block;
  font-size:14px;
  font-weight:500;
  letter-spacing:.2em;
  color:var(--p);
  margin-bottom:6px;
}
.entry h2{
  position:relative;
  margin:0 0 18px;
  padding-left:16px;
  font-size:clamp(22px,2.4vw,32px);
  line-height:1.32;
  font-weight:700;
  letter-spacing:-.01em;
}
.entry h2::before{
  content:'';
  position:absolute;
  left:0;
  top:.18em;
  bottom:.18em;
  width:6px;
  border-radius:3px;
  background:linear-gradient(180deg,var(--v),var(--p));
}
.entry h3{
  margin:26px 0 12px;
  font-size:20px;
  line-height:1.4;
  font-weight:700;
  color:#2a2040;
}
.entry p{margin:0 0 16px;color:#332b45;font-size:17px}
.entry p:last-child{margin-bottom:0}
.entry ul,.entry ol{margin:0 0 16px;padding-left:22px}
.entry li{margin-bottom:9px}
.entry li::marker{color:var(--p)}
.entry a{color:var(--v);text-underline-offset:3px}
.entry a:hover{color:var(--p)}
.entry strong{font-weight:700;color:#221a34}
.entry blockquote{
  margin:0 0 16px;
  padding:14px 20px;
  border-left:4px solid var(--p);
  border-radius:0 12px 12px 0;
  background:rgba(191,0,255,.08);
}
.entry blockquote p:last-child{margin-bottom:0}
.entry figure{margin:22px 0}
.entry figure img{width:100%;border-radius:12px;display:block}
.entry figcaption{font-size:16px;color:#5d5379;margin-top:8px}
.entry table{display:block;max-width:100%;overflow-x:auto;border-collapse:collapse;margin:0 0 18px}
.entry th,.entry td{border:1px solid var(--line);padding:9px 12px;text-align:left}
.entry th{background:rgba(101,20,255,.1)}
.entry pre{max-width:100%;overflow-x:auto;padding:14px 16px;border-radius:12px;background:#241a36;color:#f0e7ff}
.entry hr{border:0;height:1px;background:var(--line);margin:24px 0}

/* -------- 右侧小栏 -------- */
.toc{
  position:sticky;
  top:26px;
  padding:20px 18px;
  border-radius:var(--r);
  background:var(--card);
  border:1px solid rgba(101,20,255,.18);
  box-shadow:0 18px 40px -34px rgba(28,23,38,.6);
  -webkit-backdrop-filter:blur(14px);
  backdrop-filter:blur(14px);
}
.toc .kick{
  display:block;
  font-size:13px;
  font-weight:500;
  letter-spacing:.18em;
  color:var(--p);
  margin-bottom:6px;
}
.toc h2{
  margin:0 0 14px;
  font-size:20px;
  font-weight:700;
  color:#221a34;
}
.toc ul{list-style:none;margin:0;padding:0;display:grid;gap:2px}
.toc a{
  display:flex;
  align-items:center;
  min-height:40px;
  padding:8px 10px;
  border-left:2px solid transparent;
  border-radius:10px;
  font-size:16px;
  line-height:1.45;
  color:#413457;
  text-decoration:none;
  transition:background .2s ease,color .2s ease,border-color .2s ease;
}
.toc a:hover,
.toc a.on{
  background:rgba(101,20,255,.1);
  border-left-color:var(--v);
  color:var(--v);
}

/* ============ 页脚 ============ */
.foot{
  position:relative;
  z-index:1;
  margin-left:var(--side);
  margin-top:24px;
  padding:60px var(--pad) 26px;
  display:grid;
  grid-template-columns:1.5fr 1fr 1fr;
  grid-gap:40px;
  background:#1c1726;
  color:#e8ddff;
  border-radius:44px 44px 0 0;
  overflow:hidden;
}
.foot::before{
  content:'';
  position:absolute;
  left:-10%;
  right:-10%;
  bottom:-46%;
  height:240px;
  background:radial-gradient(58% 100% at 50% 100%,rgba(191,0,255,.4),transparent 72%);
  pointer-events:none;
}
.f-brand{
  font-size:clamp(30px,3.4vw,46px);
  font-weight:700;
  line-height:1.06;
  letter-spacing:-.02em;
  background:linear-gradient(100deg,#fff,#cf9dff);
  -webkit-background-clip:text;
  background-clip:text;
  color:transparent;
}
.f-mid address{
  font-style:normal;
  display:grid;
  gap:6px;
  font-size:16px;
  line-height:1.7;
  color:#c3b3e4;
  word-break:break-all;
}
.f-nav ul{list-style:none;margin:0;padding:0;display:grid;gap:2px}
.f-nav a{
  display:inline-flex;
  align-items:center;
  min-height:40px;
  padding:0 2px;
  font-size:16px;
  color:#dbcdfa;
  text-decoration:none;
  transition:color .2s ease,padding-left .2s ease;
}
.f-nav a:hover{color:#fff;padding-left:10px}
.copy{
  grid-column:1/-1;
  margin:26px 0 0;
  padding-top:18px;
  border-top:1px solid rgba(255,255,255,.16);
  font-size:16px;
  color:#b3a3d6;
}

/* -------- 回顶 -------- */
.top{
  position:fixed;
  right:18px;
  bottom:18px;
  z-index:30;
  min-height:44px;
  padding:0 18px;
  border:0;
  border-radius:999px;
  background:var(--ink);
  color:#fff;
  font:inherit;
  font-size:16px;
  cursor:pointer;
  opacity:0;
  pointer-events:none;
  transition:opacity .25s ease,transform .25s ease;
}
.top.on{opacity:1;pointer-events:auto}
.top:hover{transform:translateY(-3px)}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  body::before,
  .hero::before,
  .foot::before{animation:none}
  *{transition-duration:.01ms !important}
}

/* ============ 窄屏 ============ */
@media (max-width:980px){
  :root{--gap:32px}
  .side{
    bottom:auto;
    width:auto;
    height:auto;
    flex-direction:row;
    align-items:center;
    gap:10px;
    padding:8px 14px;
    box-shadow:0 8px 22px rgba(0,0,0,.36);
    overflow:visible;
  }
  .side::after{display:none}
  .brand{
    flex:1 1 auto;
    font-size:17px;
    line-height:1.3;
    border-left-width:3px;
    padding-left:9px;
  }
  .menu-btn{display:inline-flex;align-items:center;justify-content:center}
  .contact{margin:0;min-height:44px;padding:0 18px;font-size:16px}
  .side nav{
    position:absolute;
    top:100%;
    left:0;
    right:0;
    display:block;
    padding:10px 14px 16px;
    background:#1c1726;
    max-height:72vh;
    overflow-y:auto;
    box-shadow:0 20px 32px rgba(0,0,0,.45);
  }
  .js .side:not(.open) nav{display:none}
  .side nav ul{display:grid;grid-template-columns:1fr 1fr;gap:6px}
  .side nav li:nth-child(3){padding-bottom:0;margin-bottom:0;border-bottom:0}
  .side nav a{min-height:44px;padding:8px 10px;font-size:16px}
  main{margin-left:0;padding-top:64px}
  .hero{
    grid-template-columns:1fr;
    min-height:0;
    padding:30px 18px 78px;
    border-radius:0 0 26px 26px;
  }
  .hero-fig{min-height:180px;order:-1}
  .hero-txt{text-align:right;padding-bottom:14px}
  .hero h1{font-size:clamp(27px,7.6vw,40px);margin-bottom:20px}
  .split{grid-template-columns:1fr;padding:34px 0 56px}
  .toc{position:static;order:-1}
  .entry > div{scroll-margin-top:76px;padding:22px 18px}
  .foot{
    margin-left:0;
    grid-template-columns:1fr;
    gap:24px;
    padding:40px 18px 20px;
    border-radius:26px 26px 0 0;
  }
  .f-brand{font-size:32px}
  .copy{margin-top:20px}
}

@media (max-width:420px){
  .side nav ul{grid-template-columns:1fr}
  .hero{padding-left:14px;padding-right:14px}
  .entry > div:nth-child(even){border-left-width:4px}
  .entry > div:nth-child(odd){border-right-width:4px}
}

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