/* ==========================================================================
   华体会主站 · 共享样式 /assets/site.css
   骨架：展览画册式（大留白 + 少量强焦点）· 锐利直角 · 精密网格 · 夜光蓝
   ========================================================================== */

/* ---------- reset ---------- */
*,*::before,*::after{box-sizing:border-box;}
html,body,h1,h2,h3,h4,h5,p,ul,ol,li,figure,blockquote,dl,dd,fieldset{margin:0;padding:0;}
ul,ol{list-style:none;}
img,svg,video{display:block;max-width:100%;height:auto;}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer;}
a{color:inherit;text-decoration:none;}
table{border-collapse:collapse;width:100%;}
[hidden]{display:none !important;}

/* ---------- 变量 ---------- */
:root{
  --hth-night:#06152B;
  --hth-night-deep:#04101F;
  --hth-stand:#0F2C52;
  --hth-touch:#1E4E8C;
  --hth-neon:#28F0A8;
  --hth-mist:#A9F7DC;
  --hth-orange:#FF8A3D;
  --hth-orange-soft:#FFD8B6;
  --hth-paper:#F5F7FB;
  --hth-grid:#C6D0DD;
  --hth-ink:#0E1726;
  --hth-note:#5A6B82;
  --hth-on-dark:#E8EEF7;
  --hth-on-dark-dim:#9DB0CA;
  --hth-line:rgba(198,208,221,.18);
  --hth-line-strong:rgba(198,208,221,.36);
  --hth-hair:1px solid var(--hth-line);
  --hth-header-h:96px;
  --hth-header-h-s:68px;
  --hth-shell:1240px;
  --hth-gutter:clamp(20px,4.5vw,64px);
  --hth-serif:"Source Han Serif SC","Noto Serif SC","Songti SC","SimSun",Georgia,serif;
  --hth-sans:"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Source Han Sans SC","Noto Sans SC",system-ui,-apple-system,"Segoe UI",sans-serif;
  --hth-mono:"IBM Plex Mono","Roboto Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  --hth-ease:cubic-bezier(.22,.61,.36,1);
  --hth-shell-pad:var(--hth-gutter);
}

/* ---------- 基础排版 ---------- */
html{
  -webkit-text-size-adjust:100%;
  scroll-behavior:smooth;
  scroll-padding-top:calc(var(--hth-header-h-s) + 28px);
}
body{
  font-family:var(--hth-sans);
  font-size:17px;
  line-height:1.75;
  letter-spacing:.01em;
  color:var(--hth-on-dark);
  background-color:var(--hth-night);
  background-image:
    linear-gradient(rgba(198,208,221,.05) 1px,transparent 1px),
    linear-gradient(90deg,rgba(198,208,221,.05) 1px,transparent 1px);
  background-size:96px 96px,96px 96px;
  min-height:100vh;
}
h1,h2,h3,h4{font-weight:800;letter-spacing:-.02em;line-height:1.22;}
p{max-width:74ch;}
::selection{background:var(--hth-neon);color:var(--hth-night-deep);}
:focus-visible{outline:2px solid var(--hth-neon);outline-offset:3px;}

.hth-display{font-size:clamp(38px,6.2vw,72px);font-weight:900;letter-spacing:-.03em;line-height:1.06;}
.hth-title{font-size:clamp(26px,3.4vw,40px);font-weight:800;letter-spacing:-.02em;line-height:1.18;}
.hth-card-title{font-size:clamp(19px,2vw,23px);font-weight:700;letter-spacing:-.01em;line-height:1.35;}
.hth-eyebrow{
  font-family:var(--hth-serif);font-size:13px;letter-spacing:.34em;
  text-transform:uppercase;color:var(--hth-neon);display:block;
}
.hth-lede{font-size:clamp(17px,1.6vw,20px);line-height:1.7;color:var(--hth-on-dark);max-width:62ch;}
.hth-note{font-size:13.5px;line-height:1.7;color:var(--hth-on-dark-dim);max-width:66ch;}
.hth-num{font-family:var(--hth-mono);font-weight:600;font-variant-numeric:tabular-nums;letter-spacing:0;}
.hth-tag{
  display:inline-block;font-family:var(--hth-mono);font-size:12px;font-weight:600;
  letter-spacing:.06em;padding:3px 9px;border:1px solid var(--hth-line-strong);
  color:var(--hth-mist);white-space:nowrap;
}
.hth-rule{height:1px;border:0;background:var(--hth-line);margin:0;}

/* ---------- 容器与网格 ---------- */
.hth-shell{width:100%;max-width:var(--hth-shell);margin-inline:auto;padding-inline:var(--hth-gutter);}
.hth-grid{display:grid;gap:clamp(16px,2.2vw,28px);grid-template-columns:minmax(0,1fr);}
.hth-grid--2{grid-template-columns:repeat(2,minmax(0,1fr));}
.hth-grid--3{grid-template-columns:repeat(3,minmax(0,1fr));}
.hth-grid--split{grid-template-columns:minmax(0,7fr) minmax(0,5fr);align-items:start;}
.hth-grid--index{grid-template-columns:repeat(auto-fill,minmax(280px,1fr));}
.hth-full{width:100vw;margin-inline:calc(50% - 50vw);}

/* ---------- 页面骨架 ---------- */
.hth-page{padding-top:var(--hth-header-h);}
.hth-page--flush{padding-top:0;}
.hth-section{padding-block:clamp(56px,9vw,136px);}
.hth-section--tight{padding-block:clamp(36px,5.5vw,76px);}
.hth-slab--paper{background:var(--hth-paper);color:var(--hth-ink);}
.hth-slab--paper .hth-note{color:var(--hth-note);}
.hth-slab--paper .hth-rule{background:var(--hth-grid);}
.hth-slab--stand{background:var(--hth-stand);}
.hth-glow{
  position:absolute;inset:0;pointer-events:none;
  background:
    radial-gradient(120% 88% at 8% -10%,rgba(40,240,168,.20),transparent 58%),
    radial-gradient(92% 78% at 92% 6%,rgba(30,78,140,.62),transparent 66%),
    linear-gradient(158deg,rgba(15,44,82,.92),rgba(6,21,43,.96));
}

/* ---------- skip link ---------- */
.hth-skip{
  position:fixed;top:10px;left:10px;z-index:300;
  transform:translateY(-160%);
  background:var(--hth-neon);color:var(--hth-night-deep);
  font-size:14px;font-weight:700;padding:10px 18px;
  transition:transform .2s var(--hth-ease);
}
.hth-skip:focus{transform:translateY(0);}

/* ---------- 页头 ---------- */
.hth-header{
  position:fixed;top:0;left:0;right:0;z-index:200;
  background:linear-gradient(180deg,rgba(6,21,43,.78),rgba(6,21,43,0));
  border-bottom:1px solid transparent;
  transition:background-color .35s var(--hth-ease),border-color .35s var(--hth-ease);
}
.hth-header[data-scrolled="true"]{
  background-color:var(--hth-stand);
  background-image:none;
  border-bottom-color:var(--hth-line-strong);
}
.hth-header__progress{
  position:absolute;left:0;right:0;bottom:0;height:2px;overflow:hidden;
}
.hth-header__progress span{
  display:block;height:100%;width:100%;
  transform:scaleX(0);transform-origin:0 50%;
  background:linear-gradient(90deg,var(--hth-touch),var(--hth-neon));
}
.hth-header__inner{
  display:flex;align-items:center;gap:clamp(14px,2.4vw,40px);
  height:var(--hth-header-h);
  transition:height .3s var(--hth-ease);
}
.hth-header[data-scrolled="true"] .hth-header__inner{height:var(--hth-header-h-s);}

/* 品牌 */
.hth-brand{display:flex;align-items:center;gap:12px;flex:0 0 auto;}
.hth-brand__mark{
  width:14px;height:14px;flex:0 0 auto;
  background:var(--hth-neon);
  box-shadow:0 0 0 1px rgba(40,240,168,.45),14px 0 0 -1px transparent;
}
.hth-brand__text{display:flex;flex-direction:column;line-height:1;}
.hth-brand__word{font-size:23px;font-weight:900;letter-spacing:-.02em;color:#fff;}
.hth-brand__tagline{
  margin-top:5px;font-size:10.5px;letter-spacing:.30em;
  color:var(--hth-on-dark-dim);
}

/* 主导航 */
.hth-nav{display:flex;align-items:center;flex:1 1 auto;min-width:0;gap:clamp(16px,2.4vw,36px);}
.hth-nav__list{display:flex;align-items:center;gap:clamp(12px,1.8vw,28px);}
.hth-nav__item{position:relative;}
.hth-nav__link{
  display:block;position:relative;padding:8px 0;
  font-size:14px;letter-spacing:.02em;color:rgba(232,238,247,.76);
  transition:color .22s var(--hth-ease);
}
.hth-nav__link::after{
  content:"";position:absolute;left:0;right:0;bottom:0;height:1px;
  background:var(--hth-neon);transform:scaleX(0);transform-origin:0 50%;
  transition:transform .28s var(--hth-ease);
}
.hth-nav__link:hover{color:#fff;}
.hth-nav__link:hover::after{transform:scaleX(1);}
.hth-nav__link[aria-current="page"]{color:var(--hth-neon);}
.hth-nav__link[aria-current="page"]::after{transform:scaleX(1);background:var(--hth-neon);}
.hth-nav__actions{display:flex;align-items:center;gap:10px;margin-left:auto;flex:0 0 auto;}

/* 移动菜单按钮 */
.hth-nav-toggle{
  display:none;align-items:center;gap:10px;
  margin-left:auto;padding:10px 12px;
  border:1px solid var(--hth-line-strong);color:var(--hth-on-dark);
  font-size:13px;letter-spacing:.16em;
}
.hth-nav-toggle__bars{display:block;width:18px;height:12px;position:relative;}
.hth-nav-toggle__bars i{
  position:absolute;left:0;width:100%;height:1.5px;background:currentColor;
  transition:transform .28s var(--hth-ease),opacity .2s var(--hth-ease);
}
.hth-nav-toggle__bars i:nth-child(1){top:0;}
.hth-nav-toggle__bars i:nth-child(2){top:5px;}
.hth-nav-toggle__bars i:nth-child(3){top:10px;}
.hth-nav-toggle[aria-expanded="true"]{color:var(--hth-neon);border-color:var(--hth-neon);}
.hth-nav-toggle[aria-expanded="true"] .hth-nav-toggle__bars i:nth-child(1){transform:translateY(5px) rotate(45deg);}
.hth-nav-toggle[aria-expanded="true"] .hth-nav-toggle__bars i:nth-child(2){opacity:0;}
.hth-nav-toggle[aria-expanded="true"] .hth-nav-toggle__bars i:nth-child(3){transform:translateY(-5px) rotate(-45deg);}

/* ---------- 按钮 ---------- */
.hth-btn{
  display:inline-flex;align-items:center;justify-content:center;gap:.5em;
  padding:12px 22px;border:1px solid transparent;
  font-size:15px;font-weight:700;letter-spacing:.03em;line-height:1;
  transition:background-color .22s var(--hth-ease),color .22s var(--hth-ease),
             border-color .22s var(--hth-ease),transform .22s var(--hth-ease);
}
.hth-btn--primary{background:var(--hth-orange);color:#2A1004;}
.hth-btn--primary:hover{background:var(--hth-orange-soft);transform:translateY(-2px);}
.hth-btn--ghost{border-color:var(--hth-line-strong);color:var(--hth-on-dark);}
.hth-btn--ghost:hover{border-color:var(--hth-neon);color:var(--hth-neon);}
.hth-btn--neon{border-color:var(--hth-neon);color:var(--hth-neon);}
.hth-btn--neon:hover{background:var(--hth-neon);color:var(--hth-night-deep);}
.hth-btn--solid{background:var(--hth-touch);color:#fff;}
.hth-btn--solid:hover{background:var(--hth-neon);color:var(--hth-night-deep);}
.hth-btn--sm{padding:9px 15px;font-size:13px;}
.hth-btn--block{width:100%;}

/* ---------- 面包屑 ---------- */
.hth-crumbs{font-size:13px;color:var(--hth-on-dark-dim);}
.hth-crumbs ol{display:flex;flex-wrap:wrap;align-items:center;gap:8px;}
.hth-crumbs li{display:flex;align-items:center;gap:8px;}
.hth-crumbs li+li::before{content:"/";color:var(--hth-touch);}
.hth-crumbs a{color:var(--hth-on-dark-dim);}
.hth-crumbs a:hover{color:var(--hth-neon);}
.hth-crumbs [aria-current="page"]{color:var(--hth-on-dark);}

/* ---------- 索引目录 ---------- */
.hth-index{border-top:var(--hth-hair);}
.hth-index__item{
  display:grid;grid-template-columns:52px minmax(0,1fr) auto;
  align-items:baseline;gap:clamp(12px,2vw,28px);
  padding:20px 0;border-bottom:var(--hth-hair);
  transition:background-color .22s var(--hth-ease);
}
.hth-index__item:hover{background:rgba(30,78,140,.24);}
.hth-index__no{font-family:var(--hth-mono);font-size:13px;font-weight:600;color:var(--hth-neon);}
.hth-index__title{font-size:clamp(17px,1.7vw,20px);font-weight:700;letter-spacing:-.01em;}
.hth-index__meta{font-size:13px;color:var(--hth-on-dark-dim);white-space:nowrap;}
.hth-slab--paper .hth-index{border-top:1px solid var(--hth-grid);}
.hth-slab--paper .hth-index__item{border-bottom:1px solid var(--hth-grid);}
.hth-slab--paper .hth-index__item:hover{background:rgba(169,247,220,.35);}
.hth-slab--paper .hth-index__meta{color:var(--hth-note);}

/* ---------- 卡片与数据 ---------- */
.hth-card{
  position:relative;background:rgba(15,44,82,.62);
  border:1px solid var(--hth-line);padding:clamp(20px,2.4vw,30px);
  transition:transform .28s var(--hth-ease),border-color .28s var(--hth-ease),background-color .28s var(--hth-ease);
}
.hth-card:hover{transform:translateY(-4px);border-color:var(--hth-neon);background:rgba(15,44,82,.82);}
.hth-card--paper{
  background:var(--hth-paper);color:var(--hth-ink);border-color:var(--hth-grid);
}
.hth-card--paper:hover{background:var(--hth-paper);border-color:var(--hth-touch);}
.hth-card__title{margin-bottom:10px;}
.hth-card__meta{font-size:13px;color:var(--hth-on-dark-dim);}
.hth-card--paper .hth-card__meta{color:var(--hth-note);}
.hth-metric{display:flex;flex-direction:column;gap:6px;padding:18px 0;border-top:var(--hth-hair);}
.hth-metric__value{font-family:var(--hth-mono);font-size:clamp(30px,4.4vw,52px);font-weight:600;color:var(--hth-neon);line-height:1;}
.hth-metric__label{font-size:13px;color:var(--hth-on-dark-dim);}
.hth-slab--paper .hth-metric{border-top:1px solid var(--hth-grid);}
.hth-slab--paper .hth-metric__label{color:var(--hth-note);}

/* ---------- 主题筛选 ---------- */
.hth-filter{
  display:flex;flex-wrap:wrap;align-items:center;gap:10px;
  padding-bottom:16px;border-bottom:var(--hth-hair);
}
.hth-filter__btn{
  font-size:13.5px;font-weight:600;letter-spacing:.04em;
  padding:8px 15px;border:1px solid var(--hth-line-strong);
  color:var(--hth-on-dark-dim);
  transition:color .2s var(--hth-ease),border-color .2s var(--hth-ease),background-color .2s var(--hth-ease);
}
.hth-filter__btn:hover{color:#fff;border-color:var(--hth-mist);}
.hth-filter__btn[aria-pressed="true"]{background:var(--hth-neon);border-color:var(--hth-neon);color:var(--hth-night-deep);}
.hth-filter__count{
  margin-left:auto;font-family:var(--hth-mono);font-size:13px;color:var(--hth-on-dark-dim);
}
.hth-slab--paper .hth-filter{border-bottom:1px solid var(--hth-grid);}
.hth-slab--paper .hth-filter__btn{color:var(--hth-note);border-color:var(--hth-grid);}
.hth-slab--paper .hth-filter__btn:hover{color:var(--hth-ink);border-color:var(--hth-touch);}
.hth-slab--paper .hth-filter__btn[aria-pressed="true"]{background:var(--hth-touch);border-color:var(--hth-touch);color:#fff;}
.hth-slab--paper .hth-filter__count{color:var(--hth-note);}

/* ---------- 三步步骤条 ---------- */
.hth-steps{border-top:var(--hth-hair);}
.hth-steps__nav{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));}
.hth-steps__btn{
  display:flex;flex-direction:column;gap:8px;text-align:left;
  padding:22px 18px;border-bottom:var(--hth-hair);
  border-right:var(--hth-hair);color:var(--hth-on-dark-dim);
  transition:background-color .22s var(--hth-ease),color .22s var(--hth-ease);
}
.hth-steps__nav .hth-steps__btn:last-child{border-right:0;}
.hth-steps__btn .hth-steps__no{font-family:var(--hth-mono);font-size:13px;font-weight:600;color:var(--hth-touch);}
.hth-steps__btn .hth-steps__label{font-size:16px;font-weight:700;color:var(--hth-on-dark);}
.hth-steps__btn[aria-selected="true"]{background:rgba(30,78,140,.4);}
.hth-steps__btn[aria-selected="true"] .hth-steps__no{color:var(--hth-neon);}
.hth-steps__btn[aria-selected="true"] .hth-steps__label{color:#fff;}
.hth-steps__panel{padding:26px 0 0;}

/* ---------- 旁注导读目录 ---------- */
.hth-toc{position:sticky;top:calc(var(--hth-header-h-s) + 32px);}
.hth-toc__link{
  display:block;padding:9px 0 9px 16px;font-size:14px;
  color:var(--hth-on-dark-dim);border-left:1px solid var(--hth-line);
  transition:color .2s var(--hth-ease),border-color .2s var(--hth-ease);
}
.hth-toc__link:hover{color:#fff;border-left-color:var(--hth-mist);}
.hth-toc__link[aria-current="true"]{color:var(--hth-neon);border-left-color:var(--hth-neon);}
.hth-slab--paper .hth-toc__link{color:var(--hth-note);border-left-color:var(--hth-grid);}
.hth-slab--paper .hth-toc__link[aria-current="true"]{color:var(--hth-touch);border-left-color:var(--hth-touch);}

/* ---------- 图片容器 ---------- */
.hth-figure{
  position:relative;margin:0;overflow:hidden;
  border:1px solid var(--hth-line);
  background:
    radial-gradient(110% 90% at 12% 0%,rgba(40,240,168,.16),transparent 60%),
    linear-gradient(158deg,var(--hth-stand),var(--hth-night-deep));
  aspect-ratio:16/9;
}
.hth-figure__media{width:100%;height:100%;object-fit:cover;display:block;}
.hth-figure__cap{margin-top:10px;font-size:13px;color:var(--hth-on-dark-dim);}
.hth-figure--wide{aspect-ratio:16/7;}
.hth-figure--16x9{aspect-ratio:16/9;}
.hth-figure--4x3{aspect-ratio:4/3;}
.hth-figure--1x1{aspect-ratio:1/1;}
.hth-figure--tall{aspect-ratio:3/4;}
.hth-slab--paper .hth-figure{border-color:var(--hth-grid);}
.hth-slab--paper .hth-figure__cap{color:var(--hth-note);}

/* ---------- 页脚 ---------- */
.hth-footer{
  position:relative;margin-top:clamp(48px,7vw,110px);
  background:var(--hth-night-deep);
  border-top:1px solid var(--hth-line-strong);
}
.hth-footer__inner{padding-block:clamp(48px,7vw,92px) clamp(24px,3vw,40px);}
.hth-footer__grid{
  display:grid;grid-template-columns:1.5fr repeat(3,minmax(0,1fr));
  gap:clamp(24px,4vw,56px);
}
.hth-footer__brand{display:flex;flex-direction:column;gap:8px;}
.hth-footer__word{font-size:26px;font-weight:900;letter-spacing:-.02em;color:#fff;}
.hth-footer__tagline{font-size:12px;letter-spacing:.30em;color:var(--hth-neon);}
.hth-footer__seal{font-size:13px;color:var(--hth-on-dark-dim);}
.hth-footer__col-title{
  font-family:var(--hth-serif);font-size:13px;font-weight:500;
  letter-spacing:.24em;color:var(--hth-mist);margin-bottom:16px;
}
.hth-footer__links{display:flex;flex-direction:column;gap:10px;}
.hth-footer__links a{
  font-size:14.5px;color:var(--hth-on-dark-dim);
  transition:color .2s var(--hth-ease);
}
.hth-footer__links a:hover{color:var(--hth-neon);}
.hth-footer__contact{
  margin-top:clamp(32px,4vw,56px);padding-top:22px;
  border-top:var(--hth-hair);
  display:flex;flex-direction:column;gap:6px;
}
.hth-footer__contact-line{font-size:14px;color:var(--hth-on-dark);max-width:none;}
.hth-footer__hours{font-size:13px;color:var(--hth-on-dark-dim);max-width:none;}
.hth-footer__base{
  margin-top:22px;padding-top:18px;border-top:var(--hth-hair);
  display:flex;flex-wrap:wrap;gap:12px;justify-content:space-between;align-items:center;
}
.hth-footer__legal{font-family:var(--hth-mono);font-size:12.5px;color:var(--hth-on-dark-dim);}
.hth-footer__copy{font-size:12.5px;color:var(--hth-on-dark-dim);}

/* ---------- 动效 ---------- */
[data-reveal]{
  opacity:0;transform:translateY(16px);
  transition:opacity .45s var(--hth-ease),transform .45s var(--hth-ease);
}
[data-reveal].is-in{opacity:1;transform:none;}

/* ---------- 响应式 ---------- */
@media (max-width:1023px){
  .hth-header__inner{height:var(--hth-header-h-s);}
  .hth-nav-toggle{display:inline-flex;}
  .hth-nav{
    position:fixed;inset:0;z-index:190;
    display:flex;flex-direction:column;align-items:stretch;gap:26px;
    padding:calc(var(--hth-header-h-s) + 26px) var(--hth-gutter) 48px;
    background:var(--hth-night);overflow-y:auto;
    opacity:0;visibility:hidden;pointer-events:none;transform:translateY(-10px);
    transition:opacity .28s var(--hth-ease),transform .28s var(--hth-ease),visibility .28s;
  }
  .hth-nav[data-open="true"],
  .hth-header[data-open="true"] .hth-nav{
    opacity:1;visibility:visible;pointer-events:auto;transform:none;
  }
  .hth-nav__list{flex-direction:column;align-items:stretch;gap:0;}
  .hth-nav__item{border-bottom:var(--hth-hair);}
  .hth-nav__link{font-size:20px;padding:16px 0;color:var(--hth-on-dark);}
  .hth-nav__actions{margin-left:0;flex-direction:column;align-items:stretch;gap:12px;}
  .hth-nav__actions .hth-btn{width:100%;padding:15px 22px;}
  .hth-grid--2,.hth-grid--3,.hth-grid--split{grid-template-columns:minmax(0,1fr);}
  .hth-steps__nav{grid-template-columns:minmax(0,1fr);}
  .hth-steps__btn{border-right:0;}
  .hth-toc{position:static;}
  .hth-footer__grid{grid-template-columns:repeat(2,minmax(0,1fr));}
  .hth-footer__brand{grid-column:1 / -1;}
}
@media (max-width:599px){
  body{font-size:16px;}
  .hth-brand__word{font-size:20px;}
  .hth-brand__tagline{font-size:9.5px;letter-spacing:.22em;}
  .hth-index__item{grid-template-columns:38px minmax(0,1fr);}
  .hth-index__meta{grid-column:2;}
  .hth-footer__grid{grid-template-columns:minmax(0,1fr);}
  .hth-footer__base{flex-direction:column;align-items:flex-start;}
}
@media (max-width:1023px) and (max-height:520px) and (orientation:landscape){
  .hth-nav{padding-top:calc(var(--hth-header-h-s) + 12px);}
}

/* ---------- 可达性 ---------- */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto;}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  [data-reveal]{opacity:1;transform:none;}
}