@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500&family=Space+Grotesk:wght@500;600;700&display=swap');

:root{
  --mint:#b4fde1;
  --blue:#add8e6;
  --ink:#172620;
  --ink2:#0b1712;
  --cream:#dcf6ff;
  --muted:#a9c8b9;
  --rail:96px;
  --bar:64px;
  --r-lg:24px;
  --r-md:18px;
  --shade:inset -3px -3px 9px rgba(11,23,18,.30), inset 3px 3px 9px rgba(255,255,255,.48), 6px 6px 16px rgba(0,0,0,.42);
}

*{box-sizing:border-box}

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

body{
  margin:0;
  padding-left:var(--rail);
  background:var(--ink);
  color:#e8f7ef;
  font-family:'Inter',system-ui,-apple-system,'Segoe UI','Noto Sans SC',sans-serif;
  font-size:17px;
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
}

body::before{
  content:"";
  position:fixed;
  inset:0;
  z-index:0;
  pointer-events:none;
  background:
    radial-gradient(620px 440px at 82% 8%, rgba(173,216,230,.20), transparent 70%),
    radial-gradient(540px 440px at 8% 82%, rgba(180,253,225,.16), transparent 70%);
}

img{max-width:100%;display:block;border:0}

/* ---- 左侧竖排导轨 ---- */
.rail{
  position:fixed;
  top:0;left:0;bottom:0;
  width:var(--rail);
  z-index:50;
  display:flex;
  flex-direction:column;
  align-items:center;
  gap:16px;
  padding:18px 12px;
  background:linear-gradient(180deg,#20362c,#101f19);
  border-right:4px solid var(--ink2);
  box-shadow:inset -4px 0 12px rgba(0,0,0,.45), 8px 0 24px rgba(0,0,0,.40);
}

.brand{
  width:54px;height:54px;
  flex:0 0 auto;
  display:grid;place-items:center;
  border-radius:var(--r-md);
  border:4px solid var(--ink2);
  background:linear-gradient(160deg,var(--mint),#7fe3c4);
  color:var(--ink);
  font-family:'Space Grotesk','Inter',sans-serif;
  font-size:22px;font-weight:700;
  text-decoration:none;
  box-shadow:var(--shade);
  transition:transform .2s cubic-bezier(.34,1.56,.64,1);
}
.brand img{width:100%;height:100%;object-fit:cover;border-radius:12px}
.brand:hover,.brand:focus-visible{transform:translateY(-2px) scale(1.05)}

.menu{
  position:relative;
  width:100%;
  display:flex;
  flex-direction:column;
  align-items:center;
}
.menu summary{
  list-style:none;
  cursor:pointer;
  width:100%;
  min-height:46px;
  display:grid;place-items:center;
  border-radius:var(--r-md);
  border:4px solid var(--ink2);
  background:linear-gradient(160deg,#244036,#16261f);
  color:var(--mint);
  font-size:16px;font-weight:600;letter-spacing:.06em;
  box-shadow:var(--shade);
  transition:transform .18s ease-out, background .18s ease-out;
}
.menu summary::-webkit-details-marker{display:none}
.menu summary:hover{background:linear-gradient(160deg,#2c4a3e,#1a2c24)}
.menu summary:active{transform:translateY(2px)}
.menu[open] summary{background:linear-gradient(160deg,var(--mint),#8fe8cb);color:var(--ink)}

.railnav{
  position:fixed;
  left:var(--rail);
  top:0;bottom:0;
  width:284px;
  z-index:49;
  display:flex;
  flex-direction:column;
  gap:9px;
  padding:22px 18px;
  overflow-y:auto;
  background:linear-gradient(180deg,#1b2f26,#132019);
  border-right:4px solid var(--ink2);
  box-shadow:10px 0 30px rgba(0,0,0,.45);
  animation:slidein .28s cubic-bezier(.34,1.56,.64,1) both;
}
@keyframes slidein{from{opacity:0;transform:translateX(-16px)}to{opacity:1;transform:none}}

.railnav a{
  display:flex;
  align-items:center;
  min-height:46px;
  padding:10px 14px;
  border-radius:14px;
  border:3px solid transparent;
  color:#d8f0e5;
  text-decoration:none;
  font-size:16px;
  line-height:1.4;
  transition:background .18s ease-out, color .18s ease-out, transform .18s ease-out, border-color .18s ease-out;
}
.railnav a:hover,.railnav a:focus-visible{
  background:var(--mint);
  color:var(--ink);
  border-color:var(--ink2);
  transform:translateX(3px);
}
.railnav a:nth-child(1),
.railnav a:nth-child(3){
  margin-bottom:14px;
  box-shadow:0 12px 0 -11px rgba(180,253,225,.5);
}

/* ---- 首屏 ---- */
.hero{
  position:relative;
  z-index:1;
  min-height:100svh;
  display:grid;
  grid-template-columns:minmax(0,1.05fr) minmax(0,.95fr);
  align-items:center;
  gap:40px;
  padding:84px 40px;
  overflow:hidden;
}
.band{
  position:absolute;
  left:-16%;
  bottom:6%;
  width:132%;
  height:122px;
  z-index:0;
  border-radius:10px;
  background:linear-gradient(90deg,var(--mint),var(--blue));
  transform:rotate(-7deg);
  opacity:.92;
  box-shadow:0 20px 46px rgba(0,0,0,.38);
  will-change:transform;
}
.hero-copy{position:relative;z-index:1;max-width:580px}
.kicker{
  display:inline-block;
  margin:0 0 20px;
  padding:8px 16px;
  border-radius:999px;
  border:3px solid var(--ink2);
  background:linear-gradient(160deg,var(--blue),#8ec6dd);
  color:var(--ink);
  font-size:16px;
  font-weight:600;
  box-shadow:var(--shade);
}
h1{
  margin:0 0 20px;
  font-family:'Space Grotesk','Inter',sans-serif;
  font-size:clamp(30px,4.6vw,58px);
  line-height:1.15;
  letter-spacing:-.02em;
  color:#f2fff9;
  text-shadow:0 4px 20px rgba(0,0,0,.42);
}
.lede{
  margin:0 0 28px;
  max-width:46ch;
  font-size:18px;
  line-height:1.8;
  color:#bdd7ca;
}
.cta{
  display:inline-flex;
  align-items:center;
  min-height:52px;
  padding:12px 28px;
  border-radius:20px;
  border:4px solid var(--ink2);
  background:linear-gradient(160deg,var(--mint),#7fe3c4);
  color:var(--ink);
  font-size:17px;
  font-weight:700;
  text-decoration:none;
  box-shadow:var(--shade);
  transition:transform .2s cubic-bezier(.34,1.56,.64,1), box-shadow .2s ease-out;
}
.cta:hover{transform:translateY(-3px)}
.cta:active{
  transform:translateY(2px);
  box-shadow:inset -2px -2px 8px rgba(11,23,18,.32), inset 2px 2px 8px rgba(255,255,255,.6);
}

.hero-media{
  position:relative;
  z-index:1;
  aspect-ratio:4/3;
  border-radius:var(--r-lg);
  border:5px solid var(--ink2);
  overflow:hidden;
  background:linear-gradient(150deg,#2a4438,#1a2c24);
  box-shadow:var(--shade);
}
.hero-media:empty{background:linear-gradient(150deg,var(--blue),#5f9fb5)}
.hero-media img{width:100%;height:100%;object-fit:cover}

/* ---- 主区 ---- */
.layout{
  position:relative;
  z-index:1;
  display:grid;
  grid-template-columns:minmax(0,1fr) 288px;
  gap:26px;
  max-width:1180px;
  margin:0 auto;
  padding:56px 36px 84px;
}

.doc{min-width:0}

.doc section{
  background:var(--mint);
  color:var(--ink);
  padding:34px 32px;
  border-radius:0;
  scroll-margin-top:96px;
  animation:rise .52s ease-out both;
}
.doc section:nth-child(even){background:var(--cream)}
.doc section + section{margin-top:18px}
.doc section:nth-child(1){animation-delay:.02s}
.doc section:nth-child(2){animation-delay:.09s}
.doc section:nth-child(3){animation-delay:.16s}
.doc section:nth-child(4){animation-delay:.23s}
.doc section:nth-child(5){animation-delay:.30s}
.doc section:nth-child(6){animation-delay:.37s}
.doc section:nth-child(7){animation-delay:.44s}
@keyframes rise{from{opacity:0;transform:translateY(16px)}to{opacity:1;transform:none}}

.doc small{
  display:block;
  margin-bottom:6px;
  font-size:16px;
  font-weight:600;
  letter-spacing:.1em;
  color:#2d6149;
}
.doc h2{
  margin:0 0 16px;
  font-family:'Space Grotesk','Inter',sans-serif;
  font-size:clamp(22px,2.7vw,31px);
  line-height:1.3;
  letter-spacing:-.01em;
  color:#0e1f18;
}
.doc h3{
  margin:26px 0 10px;
  font-size:20px;
  line-height:1.4;
  color:#0e1f18;
}
.doc p{margin:0 0 15px;font-size:17px;line-height:1.85;color:#1d3229}
.doc ul,.doc ol{margin:0 0 16px;padding-left:22px;color:#1d3229}
.doc li{margin:6px 0;line-height:1.8}
.doc a{color:#0f4a37;text-decoration:underline;text-underline-offset:3px}
.doc a:hover{color:#0a2d22}
.doc strong{color:#0b1d16}
.doc blockquote{
  margin:18px 0;
  padding:16px 20px;
  background:rgba(255,255,255,.55);
  border-left:8px solid var(--ink);
  color:#152a21;
}
.doc blockquote p:last-child{margin-bottom:0}
.doc img{margin:16px 0;width:100%;height:auto}
.doc code,.doc pre{
  font-family:'JetBrains Mono',ui-monospace,monospace;
  font-size:15px;
  background:rgba(11,23,18,.09);
}
.doc code{padding:2px 6px;border-radius:6px}
.doc pre{padding:14px 16px;overflow-x:auto;border-radius:4px}

/* ---- 侧栏 ---- */
.side{
  position:sticky;
  top:24px;
  align-self:start;
  padding:22px 20px;
  border-radius:var(--r-lg);
  border:4px solid var(--ink2);
  background:linear-gradient(180deg,#22392e,#15261e);
  box-shadow:var(--shade);
}
.side-kicker{
  display:block;
  font-size:16px;
  font-weight:600;
  letter-spacing:.1em;
  color:#8fd8c0;
}
.side-title{
  margin:4px 0 16px;
  font-family:'Space Grotesk','Inter',sans-serif;
  font-size:22px;
  line-height:1.3;
  color:#eafff6;
}
.toc{
  list-style:none;
  margin:0 0 18px;
  padding:0;
  display:flex;
  flex-direction:column;
  gap:6px;
}
.toc a{
  display:flex;
  align-items:center;
  min-height:42px;
  padding:9px 12px;
  border-radius:14px;
  color:#cde8dc;
  font-size:16px;
  line-height:1.4;
  text-decoration:none;
  transition:background .18s ease-out, color .18s ease-out;
}
.toc a:hover,.toc a:focus-visible{background:var(--mint);color:var(--ink)}
.totop{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  width:100%;
  min-height:44px;
  padding:10px 14px;
  border-radius:16px;
  border:3px solid var(--ink2);
  background:linear-gradient(160deg,#2c4a3e,#1b2c24);
  color:var(--mint);
  font-size:16px;
  font-weight:600;
  text-decoration:none;
  transition:transform .18s ease-out;
}
.totop:hover{transform:translateY(-2px)}

/* ---- 页脚 ---- */
.foot{
  position:relative;
  z-index:1;
  padding:56px 36px 26px;
  background:linear-gradient(180deg,#13221b,#0c1712);
  border-top:5px solid var(--ink2);
}
.cta-block{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:22px;
  max-width:1180px;
  margin:0 auto 46px;
  padding:36px 32px;
  border-radius:var(--r-lg);
  border:5px solid var(--ink2);
  background:linear-gradient(150deg,var(--mint),#8fe8cb);
  box-shadow:var(--shade);
}
.cta-block h2{
  margin:0;
  font-family:'Space Grotesk','Inter',sans-serif;
  font-size:clamp(24px,3.2vw,38px);
  line-height:1.2;
  letter-spacing:-.02em;
  color:var(--ink);
}
.cta-go{
  display:inline-flex;
  align-items:center;
  min-height:50px;
  padding:12px 26px;
  border-radius:18px;
  border:4px solid var(--ink2);
  background:var(--ink);
  color:var(--mint);
  font-size:16px;
  font-weight:700;
  text-decoration:none;
  transition:transform .2s ease-out;
}
.cta-go:hover{transform:translateY(-3px)}

.footnav{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  gap:22px;
  max-width:1180px;
  margin:0 auto 32px;
}
.footnav dl{
  margin:0;
  padding:16px 18px;
  border-radius:var(--r-md);
  border:3px solid #1d3a2d;
  background:#132a21;
}
.footnav dt{margin:0 0 6px}
.footnav dt a{
  display:flex;
  align-items:center;
  min-height:40px;
  color:var(--mint);
  font-size:16px;
  font-weight:700;
  line-height:1.4;
  text-decoration:none;
}
.footnav dd{margin:0}
.footnav dd a{
  display:flex;
  align-items:center;
  min-height:40px;
  padding:4px 0;
  color:#b9d5c7;
  font-size:16px;
  line-height:1.4;
  text-decoration:none;
}
.footnav dt a:hover,.footnav dd a:hover{color:#ffffff}

.copy{
  max-width:1180px;
  margin:0 auto;
  padding-top:18px;
  border-top:1px solid #234234;
  color:#7fa392;
  font-size:16px;
  text-align:center;
}

/* ---- 窄屏 ---- */
@media (max-width:900px){
  body{padding-left:0;padding-top:var(--bar)}
  .rail{
    right:0;bottom:auto;
    width:100%;height:var(--bar);
    flex-direction:row;
    align-items:center;
    gap:12px;
    padding:8px 14px;
    border-right:0;
    border-bottom:4px solid var(--ink2);
    box-shadow:0 8px 20px rgba(0,0,0,.42);
  }
  .brand{width:44px;height:44px;font-size:18px}
  .menu{width:auto;margin-left:auto}
  .menu summary{width:auto;min-height:44px;padding:0 20px}
  .railnav{
    left:0;right:0;
    top:var(--bar);bottom:auto;
    width:auto;
    max-height:calc(100svh - var(--bar));
    border-right:0;
    border-bottom:4px solid var(--ink2);
  }
  .railnav a:nth-child(1),.railnav a:nth-child(3){margin-bottom:10px}

  .hero{
    grid-template-columns:1fr;
    min-height:auto;
    gap:28px;
    padding:52px 20px 60px;
  }
  .band{height:84px;bottom:14px;opacity:.85}
  h1{font-size:clamp(28px,8vw,42px)}
  .lede{font-size:17px}
  .hero-media{aspect-ratio:16/10}

  .layout{grid-template-columns:1fr;gap:22px;padding:38px 18px 58px}
  .side{position:static;order:-1}
  .doc section{padding:26px 20px}

  .foot{padding:44px 18px 22px}
  .cta-block{flex-direction:column;align-items:flex-start;padding:26px 20px;margin-bottom:34px}
  .footnav{grid-template-columns:1fr;gap:14px}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *{
    animation-duration:.001s !important;
    animation-delay:0s !important;
    transition-duration:.001s !important;
  }
}

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