/* 共用基座：导航 / 按钮 / 卡片 / 动效 / 无障碍 */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--paper); color: var(--ink);
  font-family: var(--font-cn); font-size: var(--text-base);
  line-height: 1.75; text-wrap: pretty; -webkit-font-smoothing: antialiased;
}
img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; }
h1, h2, h3, p { margin: 0; text-wrap: pretty; }
:focus-visible { outline: 3px solid var(--jade); outline-offset: 3px; border-radius: 3px; }
::selection { background: var(--jade); color: #fff; }

.container { width: 100%; max-width: var(--container); margin-inline: auto; padding-inline: clamp(20px, 4vw, 56px); }
.eyebrow {
  font-family: var(--font-en); font-size: var(--text-xs); font-weight: 600;
  letter-spacing: .28em; text-transform: uppercase; color: var(--jade-dark);
}
.eyebrow--light { color: var(--gold-soft); }
.section { padding-block: clamp(64px, 8vw, 120px); }
.section-head { display: flex; align-items: flex-end; justify-content: space-between; gap: 24px; margin-bottom: var(--s12); flex-wrap: wrap; }
.section-title { font-size: clamp(2rem, 4.2vw, 3.4rem); line-height: 1.2; font-weight: 800; letter-spacing: -.02em; }
.section-sub { color: var(--ink-soft); max-width: 46ch; margin-top: var(--s3); }

/* 导航 */
.nav {
  position: sticky; top: 0; z-index: 50; width: 100%;
  background: rgba(251, 250, 246, .92);
  backdrop-filter: saturate(1.4) blur(14px);
  border-bottom: 1px solid transparent;
  transition: box-shadow .3s var(--ease), border-color .3s var(--ease), background .3s var(--ease);
}
.nav.is-scrolled { box-shadow: var(--shadow-1); border-bottom-color: var(--line); }
.nav__inner { display: flex; align-items: center; gap: var(--s8); min-height: 76px; }
.brand { display: inline-flex; align-items: center; gap: 11px; line-height: 1; flex: none; }
.brand__mark { width: 40px; height: 40px; flex: none; display: block; }
.brand__txt { display: inline-flex; flex-direction: column; line-height: 1; }
.brand__cn { font-family: var(--font-serif); font-weight: 800; font-size: 1.4rem; letter-spacing: .16em; color: var(--forest); }
.brand__en { font-family: var(--font-en); font-size: .46rem; letter-spacing: .28em; color: var(--jade-dark); margin-top: 6px; }
.nav--over .brand__cn { color: var(--white); }
.nav--over .brand__en { color: var(--gold-soft); }
.nav__links { display: flex; gap: clamp(16px, 2.4vw, 36px); margin-left: auto; align-items: center; }
.nav__links a {
  font-size: var(--text-sm); font-weight: 500; color: var(--ink-soft);
  position: relative; padding-block: 8px; transition: color .25s var(--ease);
}
.nav__links a::after {
  content: ""; position: absolute; left: 0; right: 100%; bottom: 0; height: 2px;
  background: var(--jade); transition: right .3s var(--ease);
}
.nav__links a:hover, .nav__links a[aria-current="page"] { color: var(--forest); }
.nav__links a:hover::after, .nav__links a[aria-current="page"]::after { right: 0; }
.nav--over .nav__links a { color: rgba(255,255,255,.88); }
.nav--over .nav__links a:hover { color: #fff; }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 10px;
  min-height: 48px; padding: 0 28px; border: 1px solid transparent; border-radius: var(--r-pill);
  font-size: var(--text-sm); font-weight: 600; letter-spacing: .04em;
  transition: transform .25s var(--ease), box-shadow .25s var(--ease), background .25s var(--ease), color .25s var(--ease);
}
.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0); }
.btn:disabled { opacity: .55; pointer-events: none; }
.btn--primary { background: var(--jade); color: #fff; box-shadow: 0 8px 22px rgba(47,169,143,.28); }
.btn--primary:hover { background: var(--jade-dark); box-shadow: 0 12px 28px rgba(47,169,143,.36); }
.btn--ghost { background: transparent; color: var(--forest); border-color: var(--line-strong); }
.btn--ghost:hover { border-color: var(--jade); color: var(--jade-dark); }
.btn--light { background: var(--white); color: var(--forest); }
.btn--outline-light { background: transparent; color: #fff; border-color: rgba(255,255,255,.6); }
.btn--outline-light:hover { background: rgba(255,255,255,.12); }
.btn__arrow { font-family: var(--font-en); font-size: 1.1em; line-height: 1; }

/* 卡片 */
.card {
  position: relative; overflow: hidden; border-radius: var(--r-lg);
  background: var(--white); box-shadow: var(--shadow-1);
  transition: transform .4s var(--ease), box-shadow .4s var(--ease);
}
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow-2); }
.card img { width: 100%; height: 100%; object-fit: cover; transition: transform .8s var(--ease); }
.card:hover img { transform: scale(1.06); }

/* 滚动渐入 */
.reveal { opacity: 0; transform: translateY(28px); transition: opacity .8s var(--ease), transform .8s var(--ease); }
.reveal.is-visible { opacity: 1; transform: none; }
.reveal[data-delay="1"] { transition-delay: .1s; }
.reveal[data-delay="2"] { transition-delay: .2s; }
.reveal[data-delay="3"] { transition-delay: .3s; }

/* 页脚 */
.footer { background: var(--forest-deep); color: rgba(255,255,255,.72); padding-block: var(--s16) var(--s8); }
.footer__grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: var(--s12); padding-bottom: var(--s12); }
.footer__brand { display: flex; align-items: center; gap: 10px; font-family: var(--font-serif); font-size: 1.7rem; font-weight: 800; letter-spacing: .18em; color: #fff; }
.footer__mark { width: 34px; height: 34px; flex: none; display: block; }
.footer__tag { margin-top: var(--s3); font-size: var(--text-sm); max-width: 32ch; line-height: 1.9; }
.footer__tel a { color: var(--gold-soft); text-decoration: none; font-variant-numeric: tabular-nums; letter-spacing: .04em; }
.footer h3 { font-size: var(--text-sm); color: #fff; margin-bottom: var(--s4); letter-spacing: .1em; }
.footer ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; font-size: var(--text-sm); }
.footer a:hover { color: var(--gold-soft); }
.footer__bottom { border-top: 1px solid rgba(255,255,255,.14); padding-top: var(--s6); display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; font-size: var(--text-xs); }

/* 方案切换浮层（Tweaks） */
.tweaks { position: fixed; right: 20px; bottom: 20px; z-index: 80; font-size: var(--text-sm); }
.tweaks__toggle {
  width: 48px; height: 48px; border-radius: 50%; border: 1px solid var(--line);
  background: var(--white); color: var(--forest); box-shadow: var(--shadow-2);
  font-size: 1.15rem; line-height: 1;
}
.tweaks__panel {
  position: absolute; right: 0; bottom: 60px; width: 250px; padding: 20px;
  background: var(--white); border: 1px solid var(--line); border-radius: var(--r-md);
  box-shadow: var(--shadow-3); display: none;
}
.tweaks__panel.is-open { display: block; }
.tweaks__panel h3 { font-size: var(--text-sm); margin-bottom: var(--s4); letter-spacing: .08em; }
.tweaks__row { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding-block: 8px; }
.tweaks__row + .tweaks__row { border-top: 1px solid var(--line); }
.tweaks select, .tweaks button.link {
  border: 1px solid var(--line-strong); border-radius: var(--r-sm); background: var(--paper);
  padding: 6px 10px; color: var(--ink); font-size: var(--text-xs);
}
.tweaks a.link { display: block; margin-top: var(--s4); text-align: center; color: var(--jade-dark); font-weight: 600; }

.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
.skip-link { position: absolute; left: -9999px; top: 0; z-index: 100; background: var(--forest); color: #fff; padding: 12px 20px; }
.skip-link:focus { left: 12px; top: 12px; }

@media (max-width: 900px) {
  .nav__links { display: none; }
  .nav__inner { min-height: 64px; }
  .footer__grid { grid-template-columns: 1fr 1fr; }
  .footer__grid > :first-child { grid-column: 1 / -1; }
}
@media (max-width: 600px) {
  .footer__grid { grid-template-columns: 1fr; }
  .section-head { align-items: flex-start; }
  .btn { min-height: 46px; padding-inline: 22px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; }
  .reveal { opacity: 1; transform: none; }
}

/* 移动端顶部导航：整行可横向滑动，8 个栏目都能到达 */
@media(max-width:980px){
  .nav__inner{flex-wrap:wrap;row-gap:10px;padding-block:12px}
  .nav__inner > .btn{margin-left:auto}
  .brand__mark{width:36px;height:36px}
  .brand{gap:9px}
  .nav__links{display:flex;order:3;flex:1 0 100%;justify-content:flex-start;gap:14px;margin-left:0;flex-wrap:nowrap;overflow-x:auto;padding-bottom:4px;scrollbar-width:none;-webkit-overflow-scrolling:touch}
  .nav__links::-webkit-scrollbar{display:none}
  .nav__links a{white-space:nowrap;font-size:.8rem}
  .nav.nav--over{background:#0F2A1F}
  .nav.nav--over .brand__cn,.nav.nav--over .brand__en,.nav.nav--over .nav__links a{color:#fff}
}
@media(max-width:600px){
  .nav__links{gap:16px}
  .nav__links a{font-size:.76rem}
  .nav .btn--primary{padding:8px 14px;font-size:.78rem}
}

/* 返回顶部（含阅读进度环） */
.to-top{
  position:fixed; right:clamp(16px,2.2vw,30px);
  bottom:calc(clamp(16px,2.2vw,30px) + env(safe-area-inset-bottom, 0px));
  z-index:80; width:52px; height:52px; padding:0; border-radius:50%;
  display:grid; place-items:center; cursor:pointer;
  color:#FBFAF6; background:rgba(27,43,35,.9);
  border:1px solid rgba(201,168,106,.42);
  box-shadow:0 10px 26px rgba(9,22,17,.26), inset 0 1px 0 rgba(255,255,255,.06);
  -webkit-backdrop-filter:blur(10px); backdrop-filter:blur(10px);
  opacity:0; transform:translateY(16px) scale(.9); pointer-events:none;
  transition:opacity .36s var(--ease), transform .36s var(--ease), background .25s var(--ease), border-color .25s var(--ease), box-shadow .3s var(--ease), color .25s var(--ease);
}
.to-top.is-on{opacity:1; transform:none; pointer-events:auto}
.to-top:hover{background:var(--jade); border-color:var(--jade); color:#fff; box-shadow:0 12px 30px rgba(47,169,143,.42)}
.to-top:active{transform:scale(.93)}
.to-top__ring{position:absolute; inset:0; width:100%; height:100%; transform:rotate(-90deg); pointer-events:none}
.to-top__track{fill:none; stroke:rgba(251,250,246,.16); stroke-width:2}
.to-top__bar{fill:none; stroke:var(--gold); stroke-width:2; stroke-linecap:round; transition:stroke .25s var(--ease)}
.to-top:hover .to-top__bar{stroke:#FBFAF6}
.to-top__arrow{position:relative; width:20px; height:20px; display:block; transition:transform .25s var(--ease)}
.to-top:hover .to-top__arrow{transform:translateY(-2px)}
@media(max-width:600px){
  .to-top{width:46px; height:46px; right:14px; bottom:calc(14px + env(safe-area-inset-bottom, 0px))}
  .to-top__arrow{width:18px; height:18px}
}
@media(prefers-reduced-motion:reduce){ .to-top, .to-top__arrow{transition:opacity .01ms} }

/* 移动端导航抽屉（≤880px） */
.nav__toggle{
  display:none; flex:none; margin-left:auto; width:44px; height:44px; padding:0;
  border:1px solid rgba(31,74,56,.18); border-radius:12px; background:transparent;
  color:var(--ink); place-items:center; cursor:pointer;
  transition:background .25s var(--ease), border-color .25s var(--ease);
}
.nav--over .nav__toggle{ color:#fff; border-color:rgba(255,255,255,.34) }
.nav__links .nav__cta{ display:none }
.nav__toggle:hover{ background:rgba(47,169,143,.1) }
.nav__toggle span{ position:relative; display:block; width:18px; height:2px; background:currentColor; border-radius:2px }
.nav__toggle span::before,.nav__toggle span::after{
  content:""; position:absolute; left:0; width:18px; height:2px; background:currentColor; border-radius:2px;
  transition:transform .3s var(--ease), top .3s var(--ease);
}
.nav__toggle span::before{ top:-6px }
.nav__toggle span::after{ top:6px }
.nav__toggle[aria-expanded="true"] span{ background:transparent }
.nav__toggle[aria-expanded="true"] span::before{ top:0; transform:rotate(45deg) }
.nav__toggle[aria-expanded="true"] span::after{ top:0; transform:rotate(-45deg) }

@media(max-width:880px){
  .nav__inner{ gap:12px; min-height:64px }
  .nav__toggle{ display:grid }
  .nav .nav__inner > .btn--primary{ display:none }
  .nav .btn--primary .btn__arrow{ display:none }
  /* .nav 有 backdrop-filter，会形成包含块，故抽屉用 absolute 相对导航展开 */
  .nav__links{
    position:absolute; left:0; right:0; top:100%; bottom:auto; z-index:95; margin:0;
    display:flex; flex-direction:column; align-items:stretch; justify-content:flex-start; gap:0;
    height:calc(100vh - 64px); height:calc(100dvh - 64px);
    overflow-y:auto; -webkit-overflow-scrolling:touch;
    padding:14px clamp(22px,6vw,40px) 48px;
    background:var(--forest-deep);
    opacity:0; visibility:hidden; transform:translateY(-10px); pointer-events:none;
    transition:opacity .3s var(--ease), transform .3s var(--ease), visibility .3s;
  }
  .nav__links.is-open{ opacity:1; visibility:visible; transform:none; pointer-events:auto }
  .nav__links a{
    font-size:1.1rem; font-weight:700; letter-spacing:.06em; color:#fff;
    padding:17px 0; border-bottom:1px solid rgba(255,255,255,.14);
  }
  .nav__links a:last-child{ border-bottom:0 }
  .nav__links a[aria-current="page"]{ color:var(--jade-glow) }
  body.nav-open{ overflow:hidden }
  .nav__links .nav__cta{
    display:inline-flex; align-items:center; gap:8px; align-self:flex-start;
    margin-top:30px; padding:13px 24px; border:0; border-radius:var(--r-pill);
    background:var(--jade); color:#fff; font-size:.95rem; font-weight:700; letter-spacing:.04em;
  }
  .nav__links .nav__cta:hover{ background:var(--jade-dark); color:#fff }
}