@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

:root{
  --ink:#172623;
  --ink-soft:#22352f;
  --teal:#5cc6b0;
  --teal-deep:#2b8574;
  --link:#1f7264;
  --sand:#d4c4a8;
  --clay:#b1714d;
  --paper:#f4efe4;
  --card:#fffcf5;
  --line:#ddd2be;
  --muted:#5c6a63;
  --dock:86px;
}

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

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

body{
  margin:0;
  padding-bottom:calc(var(--dock) + 28px);
  background:var(--paper);
  color:var(--ink);
  font-family:'Inter',system-ui,'Helvetica Neue',Arial,'PingFang SC','Microsoft YaHei',sans-serif;
  font-size:17px;
  line-height:1.72;
  -webkit-font-smoothing:antialiased;
}

body::after{
  content:"";
  position:fixed;
  inset:0;
  z-index:6;
  pointer-events:none;
  opacity:.16;
  mix-blend-mode:multiply;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='g'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='3'/%3E%3CfeColorMatrix type='saturate' values='0'/%3E%3C/filter%3E%3Crect width='140' height='140' filter='url(%23g)' opacity='.55'/%3E%3C/svg%3E");
}

img{ max-width:100%; display:block; }
a{ color:var(--link); }
a:hover{ color:var(--ink); }

h1,h2,h3{ line-height:1.22; letter-spacing:-.015em; margin:0 0 .5em; font-weight:600; }
p{ margin:0 0 1em; }
ul,ol{ margin:0 0 1em; }

/* ---------- 底部固定条 ---------- */
.dock{
  position:fixed;
  left:0; right:0; bottom:0;
  z-index:50;
  display:flex;
  align-items:center;
  gap:10px;
  padding:10px clamp(12px,4vw,30px);
  background:rgba(23,38,35,.95);
  border-top:1px solid rgba(212,196,168,.28);
  backdrop-filter:blur(10px);
}

.brand{
  display:inline-flex;
  align-items:center;
  gap:9px;
  min-height:44px;
  padding:4px 6px 4px 0;
  color:var(--sand);
  text-decoration:none;
  flex:0 0 auto;
}
.brand:hover{ color:#fff; }

.brand-mark{
  width:32px; height:32px;
  display:grid;
  place-items:center;
  border:1px solid rgba(92,198,176,.75);
  border-radius:9px 13px 10px 14px;
  color:var(--teal);
  font-size:15px;
  font-weight:600;
  letter-spacing:0;
}
.brand-name{ font-size:16px; font-weight:600; letter-spacing:.02em; }

.drawer{ position:relative; flex:0 0 auto; }
.drawer summary{
  list-style:none;
  cursor:pointer;
  display:inline-flex;
  align-items:center;
  gap:8px;
  min-height:44px;
  padding:9px 13px;
  border:1px solid rgba(212,196,168,.38);
  border-radius:10px;
  color:var(--sand);
  font-size:15px;
  transition:border-color .2s ease-out, color .2s ease-out;
}
.drawer summary::-webkit-details-marker{ display:none; }
.drawer summary::marker{ content:''; }
.drawer summary:hover{ border-color:var(--teal); color:var(--teal); }

.burger{
  width:16px; height:2px;
  background:currentColor;
  box-shadow:0 5px 0 currentColor, 0 -5px 0 currentColor;
  border-radius:1px;
}

.drawer menu{
  display:none;
  position:absolute;
  bottom:calc(100% + 12px);
  left:0;
  margin:0;
  padding:8px;
  min-width:min(80vw,320px);
  max-height:64vh;
  overflow:auto;
  list-style:none;
  padding-inline-start:8px;
  background:#1d302c;
  border:1px solid rgba(212,196,168,.3);
  border-radius:14px;
  box-shadow:0 18px 40px rgba(10,20,17,.45);
}
.drawer[open] menu{ display:block; }

.drawer menu li a{
  display:flex;
  align-items:center;
  gap:10px;
  min-height:44px;
  padding:10px 12px;
  border-radius:9px;
  color:#ecdfcd;
  text-decoration:none;
  font-size:16px;
}
.drawer menu li a:hover{ background:rgba(92,198,176,.14); color:var(--teal); }
.drawer menu .num{
  font-style:normal;
  font-size:12px;
  color:var(--teal);
  font-variant-numeric:tabular-nums;
}

.drawer[open] menu li{
  animation:slideIn .28s cubic-bezier(.22,.61,.36,1) both;
}
.drawer[open] menu li:nth-child(2){ animation-delay:.03s; }
.drawer[open] menu li:nth-child(3){ animation-delay:.06s; }
.drawer[open] menu li:nth-child(4){ animation-delay:.09s; }
.drawer[open] menu li:nth-child(5){ animation-delay:.12s; }
.drawer[open] menu li:nth-child(6){ animation-delay:.15s; }
.drawer[open] menu li:nth-child(7){ animation-delay:.18s; }

.cta{
  margin-left:auto;
  display:inline-flex;
  align-items:center;
  min-height:44px;
  padding:11px 16px;
  background:var(--teal);
  color:#0f1d19;
  font-size:15px;
  font-weight:600;
  text-decoration:none;
  border-radius:10px;
  white-space:nowrap;
  transition:transform .2s ease-out, background .2s ease-out;
}
.cta:hover{ background:#74d8c3; color:#0f1d19; transform:translateY(-1px); }

/* ---------- 头图 ---------- */
.hero{
  background:var(--ink);
  color:#f4efe4;
  overflow:hidden;
}

.hero-frame{
  position:relative;
  display:flex;
  align-items:flex-end;
  justify-content:flex-end;
  min-height:66vh;
  padding:clamp(70px,12vh,120px) clamp(18px,5vw,60px) clamp(34px,6vh,56px);
}

.hero-frame::before{
  content:"";
  position:absolute;
  inset:0;
  pointer-events:none;
  background-image:radial-gradient(rgba(244,239,228,.20) 1px, transparent 1px);
  background-size:22px 22px;
  opacity:.55;
  -webkit-mask-image:linear-gradient(to left, #000, transparent 72%);
  mask-image:linear-gradient(to left, #000, transparent 72%);
}

.hero-media-wrap{ position:absolute; inset:0; overflow:hidden; }
.hero-media-wrap img{
  width:100%; height:100%;
  object-fit:cover;
  opacity:.6;
  filter:saturate(.85) contrast(1.05);
}

.hero-veil{
  position:absolute;
  inset:0;
  background:
    radial-gradient(circle at 88% 28%, rgba(92,198,176,.34), transparent 58%),
    linear-gradient(258deg, rgba(23,38,35,.28) 8%, rgba(23,38,35,.9) 66%),
    linear-gradient(to top, rgba(23,38,35,.92), transparent 55%);
}

.hero-copy{
  position:relative;
  z-index:2;
  max-width:640px;
  text-align:right;
}

.eyebrow{
  display:inline-block;
  margin:0 0 14px;
  padding:5px 12px;
  border:1px solid rgba(92,198,176,.55);
  border-radius:10px 14px 10px 14px;
  color:var(--teal);
  font-size:13px;
  letter-spacing:.20em;
  line-height:1.5;
}

.hero h1{
  font-size:clamp(29px,5.1vw,54px);
  font-weight:600;
  letter-spacing:-.03em;
  line-height:1.14;
  margin:0 0 16px;
  text-shadow:0 2px 22px rgba(8,18,15,.5);
}

.hero-lede{
  margin:0 0 0 auto;
  max-width:34em;
  color:#ded3c2;
  font-size:clamp(15px,1.6vw,18px);
  line-height:1.65;
}

/* ---------- 主体：左目录 + 右正文 ---------- */
.stage{
  max-width:1120px;
  margin:0 auto;
  padding:clamp(30px,6vw,62px) clamp(16px,4vw,32px) clamp(40px,7vw,72px);
  display:grid;
  grid-template-columns:220px minmax(0,1fr);
  gap:clamp(20px,4vw,44px);
  align-items:start;
}

.rail{
  position:sticky;
  top:24px;
  padding:16px 14px;
  background:rgba(255,252,245,.72);
  border:1px solid var(--line);
  border-left:3px solid var(--clay);
  border-radius:4px 12px 12px 4px;
}

.rail-title{
  margin:0 0 10px;
  font-size:13px;
  letter-spacing:.2em;
  color:var(--clay);
}

.rail-list{
  list-style:none;
  margin:0 0 12px;
  padding:0;
  counter-reset:rail;
}
.rail-list li{ counter-increment:rail; }
.rail-list li a{
  display:flex;
  gap:8px;
  align-items:baseline;
  min-height:38px;
  padding:7px 4px;
  font-size:15px;
  line-height:1.45;
  color:var(--ink-soft);
  text-decoration:none;
  border-bottom:1px dotted rgba(177,113,77,.35);
  transition:color .18s ease-out, padding-left .18s ease-out;
}
.rail-list li:last-child a{ border-bottom:0; }
.rail-list li a b{
  font-size:11px;
  font-weight:600;
  color:var(--teal-deep);
  font-variant-numeric:tabular-nums;
}
.rail-list li a:hover{ color:var(--clay); padding-left:8px; }

.rail-note{
  margin:0;
  font-size:12.5px;
  line-height:1.6;
  color:var(--muted);
}

.sheet{ min-width:0; max-width:768px; }

.intro{
  padding-left:16px;
  border-left:3px solid var(--teal);
  margin-bottom:clamp(24px,4vw,38px);
}
.intro h2{ font-size:clamp(20px,2.5vw,24px); }

.sheet hr{
  border:0;
  height:1px;
  margin:10px 0 18px;
  background:linear-gradient(90deg, var(--clay), rgba(177,113,77,0));
}

.body > div{
  background:var(--card);
  border:1px solid var(--line);
  border-radius:10px;
  padding:clamp(18px,3.2vw,30px);
  margin-bottom:22px;
  scroll-margin-top:24px;
  transition:border-color .22s ease-out, transform .22s ease-out;
}
.body > div:hover{ border-color:#c6b79c; transform:translateY(-2px); }
.body > div:target{ border-color:var(--teal); }

.body h2{ font-size:clamp(20px,2.6vw,26px); }
.body h3{ font-size:clamp(17px,2vw,20px); margin-top:1.4em; color:var(--ink-soft); }
.body p{ color:#26362f; }
.body ul,.body ol{ padding-left:1.25em; }
.body li{ margin-bottom:.45em; }
.body strong{ color:var(--ink); }

.body figure{ margin:0 0 1.2em; }
.body figure img{ border-radius:10px; border:1px solid var(--line); }
.body figcaption{ font-size:13.5px; color:var(--muted); margin-top:8px; }

.body blockquote{
  margin:0 0 1.2em;
  padding:12px 16px;
  border-left:3px solid var(--teal);
  background:rgba(92,198,176,.10);
  border-radius:0 10px 10px 0;
}

.body table{ width:100%; border-collapse:collapse; font-size:15.5px; }
.body th,.body td{ border:1px solid var(--line); padding:9px 11px; text-align:left; }
.body th{ background:rgba(212,196,168,.28); }

/* ---------- 页脚 ---------- */
.foot{
  background:var(--ink);
  color:#cfc4b1;
  padding:clamp(34px,6vw,54px) clamp(16px,4vw,32px) 22px;
}

.foot-cols{
  max-width:1120px;
  margin:0 auto 26px;
  display:grid;
  grid-template-columns:minmax(0,1.15fr) minmax(0,1fr);
  gap:clamp(22px,4vw,54px);
}

.foot-logo{
  margin:0 0 8px;
  color:var(--sand);
  font-size:18px;
  font-weight:600;
  letter-spacing:.02em;
}

.foot address{
  font-style:normal;
  color:var(--teal);
  font-size:14px;
  letter-spacing:.06em;
  margin-bottom:10px;
}

.foot-blurb{ margin:0; font-size:15px; line-height:1.7; color:#a9b3ac; }

.foot-links{
  list-style:none;
  margin:0;
  padding:0;
  display:grid;
  grid-template-columns:repeat(2,minmax(0,1fr));
  gap:2px 18px;
  align-content:start;
}
.foot-links a{
  display:inline-flex;
  align-items:center;
  min-height:40px;
  padding:3px 0;
  color:#cfc4b1;
  font-size:15px;
  text-decoration:none;
  border-bottom:1px solid transparent;
  transition:color .18s ease-out, border-color .18s ease-out;
}
.foot-links a:hover{ color:var(--teal); border-color:var(--teal); }

.foot-base{
  max-width:1120px;
  margin:0 auto;
  padding-top:16px;
  border-top:1px solid rgba(212,196,168,.22);
  display:flex;
  justify-content:space-between;
  align-items:center;
  gap:14px;
  flex-wrap:wrap;
  font-size:13.5px;
  color:#8e9a93;
}
.foot-base p{ margin:0; }
.foot-top a{
  display:inline-flex;
  align-items:center;
  min-height:40px;
  color:var(--sand);
  text-decoration:none;
}
.foot-top a:hover{ color:var(--teal); }

/* ---------- 动效 ---------- */
@keyframes slideIn{
  from{ opacity:0; transform:translateY(8px); }
  to{ opacity:1; transform:none; }
}
@keyframes riseIn{
  from{ opacity:0; transform:translateY(12px); }
  to{ opacity:1; transform:none; }
}

.rail-list li{ animation:riseIn .5s cubic-bezier(.22,.61,.36,1) both; }
.rail-list li:nth-child(2){ animation-delay:.05s; }
.rail-list li:nth-child(3){ animation-delay:.1s; }
.rail-list li:nth-child(4){ animation-delay:.15s; }
.rail-list li:nth-child(5){ animation-delay:.2s; }
.rail-list li:nth-child(6){ animation-delay:.25s; }

.body > div{ animation:riseIn .55s cubic-bezier(.22,.61,.36,1) both; animation-delay:.08s; }

@media (prefers-reduced-motion:reduce){
  html{ scroll-behavior:auto; }
  *,*::before,*::after{ animation:none !important; transition:none !important; }
}

/* ---------- 断点 ---------- */
@media (min-width:900px){
  .drawer{ flex:1; margin-left:22px; }
  .drawer summary{ display:none; }
  .drawer menu,
  .drawer[open] menu{
    display:flex;
    position:static;
    flex-wrap:wrap;
    justify-content:flex-end;
    gap:2px;
    min-width:0;
    max-height:none;
    overflow:visible;
    padding:0;
    background:none;
    border:0;
    border-radius:0;
    box-shadow:none;
  }
  .drawer menu li{ animation:none; }
  .drawer menu li a{
    min-height:40px;
    padding:8px 11px;
    color:#d7ccba;
    font-size:15px;
  }
  .drawer menu .num{ display:none; }
  .cta{ margin-left:14px; }
}

@media (max-width:880px){
  .stage{ grid-template-columns:1fr; }
  .rail{ position:static; }
  .rail-list{ display:grid; grid-template-columns:repeat(2,minmax(0,1fr)); gap:0 12px; }
  .rail-list li a{ border-bottom:0; }
  .sheet{ max-width:none; }
}

@media (max-width:620px){
  body{ font-size:16.5px; padding-bottom:calc(var(--dock) + 20px); }
  .hero-frame{ min-height:62vh; padding:64px 18px 34px; }
  .hero-copy{ max-width:none; }
  .brand-name{ display:none; }
  .foot-cols{ grid-template-columns:1fr; gap:20px; }
  .foot-links{ grid-template-columns:repeat(2,minmax(0,1fr)); }
  .rail-list{ grid-template-columns:1fr; }
  .rail-list li a{ border-bottom:1px dotted rgba(177,113,77,.3); }
}

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