/* ===== 01 基础重置 ===== */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body,h1,h2,h3,h4,h5,p,ul,ol,figure,blockquote{margin:0}
ul,ol{padding:0;list-style:none}
a{color:inherit;text-decoration:none}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer}
img,svg,video{display:block;max-width:100%}
input,textarea,select{font:inherit}

/* ===== 02 变量 ===== */
:root{
  --ink:#05070F;
  --ink-2:#0B1120;
  --steel:#131C33;
  --blue:#0057FF;
  --orange:#FF6A00;
  --cyan:#00E5FF;
  --paper:#F5EFE3;
  --white:#E9EEF9;
  --muted:#93A1BD;
  --green:#2ED47A;
  --edge:#1F2A44;
  --hair:rgba(0,229,255,.16);
  --hair-soft:rgba(31,42,68,.9);
  --shadow:0 24px 48px -32px rgba(0,0,0,.92);
  --ease:cubic-bezier(.22,1,.36,1);
  --font-display:"HarmonyOS Sans SC","Source Han Sans SC","Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  --font-serif:"Source Han Serif SC","Noto Serif SC","Songti SC","SimSun",Georgia,serif;
  --font-mono:"JetBrains Mono","IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  --max:1280px;
  --pad:clamp(18px,4vw,48px);
  --header-h:136px;
}

/* ===== 03 中文排版与全局 ===== */
html,body{min-height:100%}
body{
  font-family:var(--font-display);
  font-weight:400;
  font-size:16px;
  line-height:1.75;
  color:var(--white);
  background:
    radial-gradient(1100px 560px at 82% -8%,rgba(0,87,255,.18),transparent 62%),
    radial-gradient(820px 460px at 0% 0%,rgba(255,106,0,.10),transparent 58%),
    var(--ink);
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
  overflow-x:hidden;
}
body.dv-nav-open{overflow:hidden}
::selection{background:rgba(0,87,255,.6);color:#fff}
p{line-height:1.8}
[id]{scroll-margin-top:calc(var(--header-h) + 16px)}
:focus-visible{outline:2px solid var(--cyan);outline-offset:3px}
main:focus-visible{outline:2px solid var(--cyan);outline-offset:-2px}

/* ===== 04 排版工具 ===== */
.dv-display{font-family:var(--font-display);font-weight:900;font-size:clamp(40px,6vw,96px);line-height:1.02;letter-spacing:-.02em}
.dv-chapter{font-family:var(--font-serif);font-weight:600;font-size:clamp(28px,3.4vw,52px);line-height:1.22;letter-spacing:.01em}
.dv-eyebrow{font-family:var(--font-mono);font-size:12px;font-weight:500;letter-spacing:.24em;text-transform:uppercase;color:var(--cyan)}
.dv-lead{font-size:clamp(16px,1.4vw,19px);line-height:1.85;color:rgba(233,238,249,.86);max-width:62ch}
.dv-muted{color:var(--muted)}
.dv-mono{font-family:var(--font-mono);font-variant-numeric:tabular-nums;letter-spacing:.06em}

/* ===== 05 容器与分区 ===== */
.dv-container{width:100%;max-width:var(--max);margin-inline:auto;padding-inline:var(--pad)}
.dv-section{position:relative;padding:clamp(52px,7vw,110px) 0}
.dv-section--tight{padding:clamp(32px,4vw,64px) 0}
.dv-section--paper{background:var(--paper);color:#0B1120}
.dv-section--paper .dv-muted{color:#4B5568}
.dv-section--paper .dv-lead{color:#2A3446}
.dv-section--paper .dv-chapter{color:#05070F}

/* ===== 06 按钮 ===== */
.dv-btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:11px 20px;border-radius:999px;border:1px solid transparent;
  font-family:var(--font-display);font-size:14px;font-weight:500;letter-spacing:.04em;line-height:1;
  white-space:nowrap;
  transition:transform .28s var(--ease),background-color .28s var(--ease),border-color .28s var(--ease),box-shadow .28s var(--ease),color .28s var(--ease);
}
.dv-btn:hover{transform:translateY(-1px)}
.dv-btn:focus-visible{outline:2px solid var(--cyan);outline-offset:4px}
.dv-btn--primary{background:var(--blue);color:#fff;box-shadow:0 12px 28px -18px rgba(0,87,255,1)}
.dv-btn--primary:hover{background:#2A74FF;box-shadow:0 16px 32px -16px rgba(0,229,255,.72)}
.dv-btn--ghost{color:var(--white);border-color:rgba(0,229,255,.32);background:rgba(0,229,255,.05)}
.dv-btn--ghost:hover{border-color:var(--cyan);background:rgba(0,229,255,.13);color:#fff}
.dv-btn--orange{background:var(--orange);color:var(--ink);box-shadow:0 12px 28px -18px rgba(255,106,0,1)}
.dv-btn--orange:hover{background:#FF8429}
.dv-btn--sm{padding:8px 14px;font-size:13px}

/* ===== 07 头部 ===== */
.dv-header{
  position:sticky;top:0;z-index:60;
  background:linear-gradient(180deg,rgba(5,7,15,.98),rgba(11,17,32,.94));
  border-bottom:1px solid var(--hair-soft);
  transition:box-shadow .3s var(--ease),background .3s var(--ease);
}
.dv-header[data-condensed]{
  background:rgba(5,7,15,.96);
  box-shadow:0 22px 46px -34px #000;
  -webkit-backdrop-filter:blur(14px) saturate(140%);
  backdrop-filter:blur(14px) saturate(140%);
}
.dv-skip{
  position:absolute;left:50%;top:8px;z-index:90;
  transform:translate(-50%,-180%);
  padding:10px 20px;border-radius:999px;
  background:var(--cyan);color:var(--ink);
  font-family:var(--font-display);font-size:13px;font-weight:700;letter-spacing:.04em;
  transition:transform .22s var(--ease);
}
.dv-skip:focus,.dv-skip:focus-visible{transform:translate(-50%,0);outline:2px solid var(--white);outline-offset:2px}
.dv-header__inner{
  display:grid;grid-template-columns:1fr auto 1fr;
  align-items:center;gap:20px;
  padding:18px 0 14px;
  transition:padding .3s var(--ease),gap .3s var(--ease);
}
.dv-header__edition{
  justify-self:start;display:flex;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.16em;
  text-transform:uppercase;color:var(--muted);
}
.dv-header__edition-sep{color:var(--orange)}
.dv-masthead{grid-column:2;display:flex;flex-direction:column;align-items:center;gap:5px;text-align:center}
.dv-brand{display:inline-flex;align-items:center;gap:10px}
.dv-brand__mark{
  width:26px;height:26px;flex:none;
  background:linear-gradient(135deg,var(--blue) 0 52%,var(--orange) 52% 100%);
  clip-path:polygon(0 0,100% 0,100% 70%,70% 100%,0 100%);
  transition:width .3s var(--ease),height .3s var(--ease);
}
.dv-brand__name{
  font-family:var(--font-display);font-weight:900;
  font-size:clamp(20px,2.4vw,30px);line-height:1.1;letter-spacing:-.02em;color:var(--white);
  transition:font-size .3s var(--ease);
}
.dv-brand__meta{
  font-family:var(--font-mono);font-size:10px;letter-spacing:.12em;
  color:var(--cyan);padding:2px 7px;border:1px solid var(--hair);border-radius:999px;
}
.dv-masthead__note{font-family:var(--font-mono);font-size:10px;letter-spacing:.28em;color:var(--muted)}
.dv-actions{grid-column:3;justify-self:end;display:flex;align-items:center;gap:10px}
.dv-nav-toggle{
  display:none;grid-column:3;justify-self:end;align-items:center;gap:9px;
  padding:9px 15px;border:1px solid rgba(0,229,255,.32);border-radius:999px;
  color:var(--white);background:rgba(0,229,255,.05);
}
.dv-nav-toggle__label{font-family:var(--font-mono);font-size:11px;letter-spacing:.16em}
.dv-nav-toggle__bars{display:inline-flex;flex-direction:column;gap:3.5px;width:16px}
.dv-nav-toggle__bars span{display:block;height:1.5px;background:var(--cyan);transition:transform .26s var(--ease),opacity .18s linear}
.dv-header[data-open] .dv-nav-toggle{border-color:var(--orange);color:var(--orange)}
.dv-header[data-open] .dv-nav-toggle__bars span{background:var(--orange)}
.dv-header[data-open] .dv-nav-toggle__bars span:nth-child(1){transform:translateY(5px) rotate(45deg)}
.dv-header[data-open] .dv-nav-toggle__bars span:nth-child(2){opacity:0}
.dv-header[data-open] .dv-nav-toggle__bars span:nth-child(3){transform:translateY(-5px) rotate(-45deg)}

/* 导航条 */
.dv-nav{position:relative;border-top:1px solid var(--hair-soft)}
.dv-nav__list{
  counter-reset:dvnav;
  max-width:var(--max);margin-inline:auto;
  padding:0 clamp(12px,3vw,28px);
  display:flex;justify-content:center;align-items:center;flex-wrap:wrap;gap:2px;
}
.dv-nav__item{display:flex}
.dv-nav__link{
  position:relative;display:inline-flex;align-items:baseline;gap:7px;
  padding:13px 18px;border-radius:2px;
  font-family:var(--font-display);font-size:14px;font-weight:500;letter-spacing:.04em;
  color:rgba(233,238,249,.82);counter-increment:dvnav;
  transition:color .24s var(--ease),background-color .24s var(--ease);
}
.dv-nav__link::before{
  content:counter(dvnav,decimal-leading-zero);
  font-family:var(--font-mono);font-size:10px;font-weight:500;letter-spacing:.06em;
  color:var(--orange);opacity:.7;transition:opacity .24s var(--ease),color .24s var(--ease);
}
.dv-nav__link::after{
  content:"";position:absolute;left:18px;right:18px;bottom:8px;height:2px;
  background:linear-gradient(90deg,var(--cyan),var(--blue));
  transform:scaleX(0);transform-origin:left center;
  transition:transform .34s var(--ease);
}
.dv-nav__link:hover{color:#fff;background:rgba(0,229,255,.05)}
.dv-nav__link:hover::after{transform:scaleX(1)}
.dv-nav__link[aria-current="page"]{color:#fff}
.dv-nav__link[aria-current="page"]::before{opacity:1;color:var(--cyan)}
.dv-nav__link[aria-current="page"]::after{transform:scaleX(1);background:linear-gradient(90deg,var(--orange),var(--cyan))}
.dv-nav__ctas{display:none}

/* 阅读进度 */
.dv-progress{position:absolute;left:0;right:0;bottom:0;height:2px;background:rgba(0,229,255,.1);pointer-events:none}
.dv-progress__bar{
  display:block;height:100%;width:100%;
  transform:scaleX(0);transform-origin:left center;
  background:linear-gradient(90deg,var(--blue),var(--cyan) 58%,var(--orange));
  transition:transform .12s linear;
}

/* 收窄态 */
.dv-header[data-condensed] .dv-header__inner{grid-template-columns:auto 1fr auto;padding:10px 0 8px;gap:14px}
.dv-header[data-condensed] .dv-header__edition{display:none}
.dv-header[data-condensed] .dv-masthead{grid-column:1;flex-direction:row;align-items:center;gap:10px}
.dv-header[data-condensed] .dv-masthead__note{display:none}
.dv-header[data-condensed] .dv-brand__mark{width:20px;height:20px}
.dv-header[data-condensed] .dv-brand__name{font-size:20px}
.dv-header[data-condensed] .dv-actions{grid-column:3}
.dv-header[data-condensed] .dv-nav__link{padding:8px 15px;font-size:13px}
.dv-header[data-condensed] .dv-nav__link::after{bottom:3px}

/* ===== 08 页脚 ===== */
.dv-footer{
  position:relative;
  background:linear-gradient(180deg,var(--ink-2),var(--ink) 72%);
  border-top:1px solid var(--hair-soft);
  color:var(--muted);
  padding:clamp(42px,6vw,82px) 0 0;
}
.dv-footer::before{
  content:"";position:absolute;top:0;left:0;right:0;height:2px;
  background:linear-gradient(90deg,var(--blue),var(--cyan) 46%,var(--orange));
}
.dv-footer__grid{
  display:grid;grid-template-columns:1.4fr 1fr 1fr 1.3fr;
  gap:clamp(24px,3vw,48px);
}
.dv-footer__col{min-width:0}
.dv-footer__title{
  font-family:var(--font-mono);font-size:11px;font-weight:500;
  letter-spacing:.22em;text-transform:uppercase;color:var(--cyan);
  margin-bottom:16px;
}
.dv-footer__list{display:grid;gap:10px;font-size:14px;line-height:1.6}
.dv-footer__list a{
  position:relative;display:inline-block;color:rgba(233,238,249,.78);
  transition:color .24s var(--ease);
}
.dv-footer__list a::after{
  content:"";position:absolute;left:0;right:0;bottom:-2px;height:1px;
  background:var(--orange);transform:scaleX(0);transform-origin:left center;
  transition:transform .3s var(--ease);
}
.dv-footer__list a:hover{color:#fff}
.dv-footer__list a:hover::after{transform:scaleX(1)}
.dv-brand--footer .dv-brand__name{font-size:22px}
.dv-footer__tagline{
  font-family:var(--font-serif);font-size:clamp(16px,1.6vw,20px);line-height:1.6;
  color:var(--white);margin-top:16px;max-width:22ch;
}
.dv-footer__meta{font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;color:var(--muted);margin-top:14px}
.dv-footer__contact{font-size:13px;line-height:1.7;color:var(--muted);word-break:break-word}
.dv-footer__contact .dv-mono{color:var(--cyan);margin-right:8px;font-size:10px;letter-spacing:.16em}
.dv-footer__note{
  margin-top:14px;font-size:12px;line-height:1.7;
  color:rgba(147,161,189,.82);max-width:34ch;
}
.dv-footer__bottom{
  margin-top:clamp(32px,5vw,56px);
  border-top:1px solid var(--hair-soft);
  padding:18px 0 26px;
  display:flex;flex-wrap:wrap;gap:10px 24px;align-items:center;justify-content:space-between;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.06em;color:var(--muted);
}
.dv-footer__legal{display:flex;flex-wrap:wrap;gap:18px}

/* ===== 09 斜切章节色带 ===== */
.dv-band{
  position:relative;isolation:isolate;overflow:hidden;
  display:flex;align-items:center;gap:clamp(14px,3vw,28px);
  min-height:88px;
  padding:clamp(16px,2.6vw,26px) var(--pad);
  background:linear-gradient(100deg,var(--steel),var(--ink-2));
  border-top:1px solid var(--edge);border-bottom:1px solid var(--edge);
}
.dv-band::before{
  content:"";position:absolute;left:-8%;top:0;bottom:0;width:46%;z-index:-1;
  background:linear-gradient(120deg,var(--blue),#002A80);
  transform:skewX(-12deg);transform-origin:left center;opacity:.94;
}
.dv-band__index{font-family:var(--font-mono);font-size:12px;font-weight:500;letter-spacing:.2em;color:var(--cyan)}
.dv-band__title{font-family:var(--font-serif);font-weight:600;font-size:clamp(20px,3vw,34px);line-height:1.25;color:var(--white)}
.dv-band--orange::before{background:linear-gradient(120deg,var(--orange),#B34000)}
.dv-band--orange .dv-band__index{color:var(--ink)}

/* ===== 10 卡片 / 标签 ===== */
.dv-card{
  position:relative;
  background:linear-gradient(180deg,rgba(19,28,51,.74),rgba(11,17,32,.94));
  border:1px solid var(--hair-soft);border-radius:18px;
  padding:clamp(18px,2.2vw,28px);
  box-shadow:var(--shadow);
  transition:transform .32s var(--ease),border-color .32s var(--ease),box-shadow .32s var(--ease);
}
.dv-card:hover{transform:translateY(-4px);border-color:rgba(0,229,255,.55);box-shadow:0 30px 60px -34px rgba(0,87,255,.72)}
.dv-card--paper{background:var(--paper);color:var(--ink-2);border-color:rgba(11,17,32,.14)}
.dv-card--offset{margin-top:clamp(16px,3vw,48px)}
.dv-tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:4px 10px;border-radius:999px;
  font-family:var(--font-mono);font-size:11px;font-weight:500;letter-spacing:.12em;text-transform:uppercase;
  color:var(--orange);background:rgba(255,106,0,.12);border:1px solid rgba(255,106,0,.36);
}
.dv-tag--blue{color:#8FB4FF;background:rgba(0,87,255,.16);border-color:rgba(0,87,255,.48)}
.dv-tag--cyan{color:var(--cyan);background:rgba(0,229,255,.1);border-color:rgba(0,229,255,.36)}

/* ===== 11 网格 ===== */
.dv-grid{display:grid;gap:clamp(18px,2.6vw,36px)}
.dv-grid--7-5{grid-template-columns:minmax(0,7fr) minmax(0,5fr)}
.dv-grid--8-4{grid-template-columns:minmax(0,8fr) minmax(0,4fr)}
.dv-grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
.dv-grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}

/* ===== 12 图片容器基础 ===== */
.dv-media{
  position:relative;isolation:isolate;overflow:hidden;
  border-radius:16px;border:1px solid var(--hair);
  background:linear-gradient(145deg,var(--steel),var(--ink-2));
}
.dv-media img,.dv-media video{width:100%;height:100%;object-fit:cover;display:block}
.dv-media--16x9{aspect-ratio:16/9}
.dv-media--4x3{aspect-ratio:4/3}
.dv-media--1x1{aspect-ratio:1/1}
.dv-media--tall{aspect-ratio:3/4}
.dv-media--overlay::after{
  content:"";position:absolute;inset:0;z-index:1;pointer-events:none;
  background:linear-gradient(180deg,rgba(5,7,15,0) 48%,rgba(5,7,15,.72));
}
.dv-media__cap{
  position:absolute;left:14px;bottom:12px;z-index:2;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;color:var(--cyan);
}

/* ===== 13 面包屑 / 目录 ===== */
.dv-breadcrumb{font-family:var(--font-mono);font-size:12px;letter-spacing:.08em;color:var(--muted)}
.dv-breadcrumb ol{display:flex;flex-wrap:wrap;align-items:center;gap:8px}
.dv-breadcrumb li{display:flex;align-items:center;gap:8px}
.dv-breadcrumb li+li::before{content:"/";color:rgba(0,229,255,.5)}
.dv-breadcrumb a{color:rgba(233,238,249,.8);transition:color .24s var(--ease)}
.dv-breadcrumb a:hover{color:var(--cyan)}
.dv-breadcrumb [aria-current="page"]{color:var(--white)}
.dv-toc{position:sticky;top:calc(var(--header-h) + 20px);font-size:13px}
.dv-toc__title{
  font-family:var(--font-mono);font-size:11px;letter-spacing:.22em;text-transform:uppercase;
  color:var(--cyan);margin-bottom:12px;
}
.dv-toc__list{display:grid;gap:2px;border-left:1px solid var(--hair-soft);padding-left:14px}
.dv-toc a{
  display:block;padding:7px 0;color:var(--muted);
  font-family:var(--font-display);font-size:13px;letter-spacing:.03em;
  transition:color .24s var(--ease);
}
.dv-toc a:hover{color:var(--white)}
.dv-toc a[aria-current="true"],.dv-toc a.is-active{color:var(--cyan)}

/* ===== 14 返回顶部 / 显现 ===== */
.dv-totop{
  position:fixed;right:clamp(14px,3vw,32px);bottom:clamp(14px,3vw,32px);z-index:55;
  display:inline-flex;flex-direction:column;align-items:center;justify-content:center;gap:1px;
  width:52px;height:52px;border-radius:50%;
  border:1px solid rgba(0,229,255,.42);background:rgba(11,17,32,.92);
  color:var(--cyan);font-family:var(--font-mono);
  opacity:0;transform:translateY(10px);pointer-events:none;
  transition:opacity .3s var(--ease),transform .3s var(--ease),border-color .3s var(--ease),color .3s var(--ease);
}
.dv-totop[data-visible]{opacity:1;transform:none;pointer-events:auto}
.dv-totop:hover{border-color:var(--orange);color:var(--orange)}
.dv-totop__glyph{font-size:14px;line-height:1}
.dv-totop__label{font-size:9px;letter-spacing:.1em}
html.dv-js [data-reveal]{
  opacity:0;transform:translateY(12px);
  transition:opacity .4s var(--ease),transform .4s var(--ease);
}
html.dv-js [data-reveal].is-visible{opacity:1;transform:none}

/* ===== 15 响应式：平板 ===== */
@media (max-width:1100px){
  .dv-header__edition{display:none}
  .dv-header__inner{grid-template-columns:auto 1fr auto}
  .dv-masthead{grid-column:2}
}
@media (max-width:1000px){
  .dv-grid--7-5,.dv-grid--8-4{grid-template-columns:minmax(0,1fr)}
  .dv-footer__grid{grid-template-columns:repeat(2,minmax(0,1fr))}
  .dv-toc{position:static;top:auto}
}

/* ===== 16 响应式：手机 ===== */
@media (max-width:900px){
  :root{--header-h:96px}
  .dv-header__inner,
  .dv-header[data-condensed] .dv-header__inner{
    grid-template-columns:1fr auto;padding:12px 0;gap:12px;
  }
  .dv-header__edition,.dv-header[data-condensed] .dv-header__edition{display:none}
  .dv-masthead,
  .dv-header[data-condensed] .dv-masthead{
    grid-column:1;justify-self:start;flex-direction:row;align-items:center;gap:10px;text-align:left;
  }
  .dv-masthead__note,.dv-header[data-condensed] .dv-masthead__note{display:none}
  .dv-actions{display:none}
  .dv-nav-toggle{display:inline-flex}
  .dv-brand__name,.dv-header[data-condensed] .dv-brand__name{font-size:20px}
  .dv-brand__mark,.dv-header[data-condensed] .dv-brand__mark{width:22px;height:22px}
  .dv-nav{
    position:absolute;top:100%;left:0;right:0;
    display:none;
    background:rgba(5,7,15,.99);
    border-top:1px solid var(--hair);
    box-shadow:0 26px 46px -30px #000;
    max-height:74vh;overflow-y:auto;
    padding:6px clamp(16px,5vw,28px) 22px;
  }
  .dv-header[data-open] .dv-nav{display:block}
  .dv-nav__list{flex-direction:column;align-items:stretch;gap:0;padding:0}
  .dv-nav__link,
  .dv-header[data-condensed] .dv-nav__link{
    display:flex;padding:14px 2px;font-size:14px;border-radius:0;
    border-bottom:1px solid rgba(31,42,68,.9);
  }
  .dv-nav__link::after,
  .dv-header[data-condensed] .dv-nav__link::after{left:2px;right:auto;width:30px;bottom:9px}
  .dv-nav__ctas{display:flex;flex-wrap:wrap;gap:10px;padding-top:16px}
  .dv-grid--3,.dv-grid--2{grid-template-columns:minmax(0,1fr)}
  .dv-footer__grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:28px}
  .dv-footer__tagline{max-width:none}
}
@media (max-width:560px){
  .dv-footer__grid{grid-template-columns:minmax(0,1fr)}
  .dv-footer__bottom{justify-content:flex-start;flex-direction:column;align-items:flex-start}
  .dv-band{min-height:76px}
  .dv-totop{width:46px;height:46px}
}

/* ===== 17 动效降级 ===== */
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  html.dv-js [data-reveal]{opacity:1;transform:none}
  .dv-btn:hover,.dv-card:hover,.dv-totop{transform:none}
  .dv-progress__bar{transition:none}
}