:root{
  --color-bg:#0D0E13;
  --color-surface:#191B22;
  --color-surface-raised:#1E212A;
  --color-border:#2A2E3A;
  --color-text:#E8EAF0;
  --color-text-muted:#9BA3A0;
  --color-accent-a:#E5368A;
  --color-accent-b:#00D4FF;
  --color-neon-gradient:linear-gradient(90deg,var(--color-accent-a),var(--color-accent-b));
  --color-nature-green:#4A5D4E;
  --color-nature-teal:#2B3A32;
  --color-nature-clay:#C67B4E;
  --color-nature-cream:#F2EDE4;
  --font-sans:"Noto Sans SC","PingFang SC","Microsoft YaHei",sans-serif;
  --font-head:"Noto Sans SC","PingFang SC","Microsoft YaHei",sans-serif;
  --font-mono:"JetBrains Mono","SF Mono","Consolas",monospace;
  --space-unit:16px;
  --header-width:280px;
  --radius-sm:8px;
  --radius-md:16px;
  --radius-pill:999px;
  --shadow-card:0 8px 30px rgba(0,0,0,0.3);
  --transition-fast:180ms ease;
  --transition-base:260ms cubic-bezier(0.2,0.7,0.3,1);
}

*,
*::before,
*::after{
  box-sizing:border-box;
  margin:0;
  padding:0;
}

html{
  scroll-behavior:smooth;
}

@media(prefers-reduced-motion:reduce){
  html{
    scroll-behavior:auto;
  }
  *,
  *::before,
  *::after{
    animation-duration:0.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:0.001ms !important;
  }
}

body{
  font-family:var(--font-sans);
  background-color:var(--color-bg);
  color:var(--color-text);
  line-height:1.7;
  min-height:100vh;
}

a{
  color:var(--color-accent-b);
  text-decoration:none;
}

a:hover{
  color:var(--color-accent-a);
  text-decoration:underline;
  text-underline-offset:4px;
}

:focus-visible{
  outline:2px solid var(--color-accent-b);
  outline-offset:4px;
  border-radius:3px;
}

.skip-link{
  position:fixed;
  top:-80px;
  left:12px;
  z-index:2000;
  background:var(--color-accent-a);
  color:#fff;
  padding:8px 20px;
  border-radius:var(--radius-pill);
  font-weight:700;
  transition:top var(--transition-fast);
}

.skip-link:focus{
  top:12px;
}

.reading-progress{
  position:fixed;
  top:0;
  left:0;
  height:4px;
  background:var(--color-neon-gradient);
  width:0%;
  z-index:1500;
  box-shadow:0 0 12px rgba(0,212,255,0.4);
  transition:width 120ms linear;
}

@media(prefers-reduced-motion:reduce){
  .reading-progress{
    transition:none;
  }
}

.site-shell{
  display:grid;
  grid-template-columns:var(--header-width) 1fr;
  min-height:100vh;
}

.nav-frame{
  position:fixed;
  top:0;
  left:0;
  bottom:0;
  width:var(--header-width);
  background:var(--color-surface);
  border-right:1px solid var(--color-border);
  display:flex;
  flex-direction:column;
  z-index:1000;
}

.nav-inner{
  display:flex;
  flex-direction:column;
  height:100%;
  padding:24px 20px;
  overflow-y:auto;
}

.brand-mark{
  display:flex;
  align-items:center;
  gap:12px;
  padding:12px 8px;
  border-radius:var(--radius-md);
  color:var(--color-text);
}

.brand-mark:hover{
  background:var(--color-surface-raised);
  text-decoration:none;
}

.brand-glyph{
  flex-shrink:0;
  width:42px;
  height:42px;
  border-radius:14px;
  background:var(--color-neon-gradient);
  position:relative;
  box-shadow:0 0 16px rgba(229,54,138,0.35);
}

.brand-glyph::after{
  content:"";
  position:absolute;
  inset:4px;
  border-radius:10px;
  border:2px solid var(--color-bg);
  background:linear-gradient(145deg,var(--color-bg),var(--color-surface-raised));
}

.brand-glyph::before{
  content:"";
  position:absolute;
  inset:0;
  border-radius:14px;
  border:1px solid rgba(0,212,255,0.6);
  z-index:1;
}

.brand-text{
  display:flex;
  flex-direction:column;
}

.brand-name{
  font-family:var(--font-head);
  font-size:20px;
  font-weight:900;
  letter-spacing:-0.02em;
  background:var(--color-neon-gradient);
  -webkit-background-clip:text;
  background-clip:text;
  -webkit-text-fill-color:transparent;
}

.brand-slogan{
  font-size:12px;
  color:var(--color-text-muted);
  margin-top:2px;
}

.nav-toggle{
  display:none;
  position:absolute;
  top:20px;
  right:16px;
  z-index:1100;
  width:48px;
  height:48px;
  border:none;
  background:var(--color-surface-raised);
  border-radius:14px;
  cursor:pointer;
  flex-direction:column;
  align-items:center;
  justify-content:center;
  gap:6px;
}

.toggle-bar{
  display:block;
  width:22px;
  height:2px;
  background:var(--color-text);
  border-radius:2px;
  transition:transform var(--transition-fast), opacity var(--transition-fast);
}

.nav-toggle[aria-expanded="true"] .toggle-bar:nth-child(1){
  transform:translateY(8px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .toggle-bar:nth-child(2){
  opacity:0;
}

.nav-toggle[aria-expanded="true"] .toggle-bar:nth-child(3){
  transform:translateY(-8px) rotate(-45deg);
}

.primary-nav{
  margin-top:24px;
  flex:1;
}

.nav-list{
  list-style:none;
  display:flex;
  flex-direction:column;
  gap:6px;
}

.nav-link{
  display:block;
  padding:10px 14px;
  border-radius:var(--radius-pill);
  color:var(--color-text);
  font-size:15px;
  font-weight:500;
  position:relative;
  transition:background var(--transition-fast), color var(--transition-fast), transform var(--transition-fast);
}

.nav-link::before{
  content:"";
  position:absolute;
  left:0;
  top:50%;
  width:3px;
  height:0;
  background:var(--color-neon-gradient);
  border-radius:3px;
  transform:translateY(-50%);
  transition:height var(--transition-base);
}

.nav-link:hover{
  background:var(--color-surface-raised);
  color:var(--color-accent-b);
  transform:translateX(4px);
  text-decoration:none;
}

.nav-link[aria-current="page"]{
  background:var(--color-neon-gradient);
  color:var(--color-bg);
  font-weight:700;
  box-shadow:0 0 16px rgba(229,54,138,0.2);
}

.nav-link[aria-current="page"]::before,
.nav-link[aria-current="page"]:hover::before{
  height:0;
}

.nav-link[aria-current="page"]:hover{
  color:var(--color-bg);
  transform:none;
}

.nav-search-item{
  margin-top:24px;
  padding-top:24px;
  border-top:1px solid var(--color-border);
}

.search-icon{
  display:none;
}

.search-field{
  width:100%;
  background:var(--color-bg);
  border:1px solid var(--color-border);
  border-radius:var(--radius-pill);
  padding:10px 16px;
  color:var(--color-text);
  font-size:14px;
  font-family:var(--font-sans);
  transition:border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.search-field::placeholder{
  color:var(--color-text-muted);
}

.search-field:focus{
  outline:none;
  border-color:var(--color-accent-b);
  box-shadow:0 0 0 3px rgba(0,212,255,0.2);
}

.status-strip{
  display:flex;
  align-items:center;
  gap:8px;
  padding:10px 14px;
  background:var(--color-bg);
  border:1px solid var(--color-border);
  border-radius:var(--radius-pill);
  font-family:var(--font-mono);
  font-size:11px;
  color:var(--color-text-muted);
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
}

.status-dot{
  width:8px;
  height:8px;
  flex-shrink:0;
  background:var(--color-nature-green);
  border-radius:50%;
  box-shadow:0 0 8px rgba(74,93,78,0.8);
  animation:pulse-dot 2.4s ease-in-out infinite;
}

@keyframes pulse-dot{
  0%,100%{opacity:0.6;transform:scale(0.9);}
  50%{opacity:1;transform:scale(1.15);}
}

@media(prefers-reduced-motion:reduce){
  .status-dot{
    animation:none;
  }
}

.content-container{
  grid-column:2;
  max-width:1100px;
  margin:0 auto;
  padding:48px 32px 96px 32px;
  width:100%;
}

.page-header{
  margin-bottom:64px;
}

.chapter-index{
  font-family:var(--font-mono);
  font-size:14px;
  color:var(--color-accent-a);
  letter-spacing:0.08em;
  text-transform:uppercase;
}

.page-title{
  font-family:var(--font-head);
  font-weight:900;
  font-size:clamp(44px,7vw,88px);
  line-height:1.05;
  letter-spacing:-0.04em;
  margin:12px 0 20px 0;
  background:var(--color-neon-gradient);
  -webkit-background-clip:text;
  background-clip:text;
  -webkit-text-fill-color:transparent;
}

.page-description{
  font-size:18px;
  max-width:720px;
  color:var(--color-text-muted);
  border-left:3px solid var(--color-accent-b);
  padding-left:20px;
}

.breadcrumb{
  font-family:var(--font-mono);
  font-size:13px;
  color:var(--color-text-muted);
  margin-bottom:24px;
  display:flex;
  flex-wrap:wrap;
  gap:6px;
}

.breadcrumb a{
  color:var(--color-accent-b);
}

.breadcrumb a:hover{
  color:var(--color-accent-a);
}

.breadcrumb .sep{
  color:var(--color-border);
}

.card{
  background:var(--color-surface);
  border:1px solid var(--color-border);
  border-radius:var(--radius-md);
  padding:24px;
  transition:transform var(--transition-base), box-shadow var(--transition-base);
}

.card:hover{
  transform:translateY(-4px);
  box-shadow:var(--shadow-card);
  border-color:rgba(0,212,255,0.4);
}

.card h3{
  font-family:var(--font-head);
  font-size:22px;
  font-weight:700;
  color:var(--color-text);
  margin-bottom:8px;
}

.card p{
  color:var(--color-text-muted);
  font-size:15px;
  line-height:1.7;
}

.card a{
  color:var(--color-accent-b);
}

.media-frame{
  background:var(--color-surface-raised);
  border:1px solid var(--color-border);
  border-radius:var(--radius-md);
  overflow:hidden;
  position:relative;
  display:flex;
  align-items:center;
  justify-content:center;
  color:var(--color-text-muted);
}

.media-frame::before{
  content:attr(data-placeholder);
  font-family:var(--font-mono);
  font-size:13px;
  text-align:center;
  padding:0 16px;
  opacity:0.6;
}

.media-4x3{
  aspect-ratio:4/3;
}

.media-16x9{
  aspect-ratio:16/9;
}

.media-1x1{
  aspect-ratio:1/1;
}

.grid{
  display:grid;
  gap:24px;
}

.grid-2{
  grid-template-columns:repeat(2,1fr);
}

.grid-3{
  grid-template-columns:repeat(3,1fr);
}

.scroll-fade{
  opacity:0;
  transform:translateY(16px);
  transition:opacity 0.6s ease, transform 0.6s ease;
}

.scroll-fade.is-visible{
  opacity:1;
  transform:translateY(0);
}

@media(prefers-reduced-motion:reduce){
  .scroll-fade{
    opacity:1;
    transform:none;
    transition:none;
  }
}

.site-footer{
  grid-column:2;
  background:var(--color-surface);
  border-top:1px solid var(--color-border);
  padding:48px 32px 24px 32px;
}

.footer-grid{
  max-width:1100px;
  margin:0 auto;
  display:grid;
  grid-template-columns:1.4fr 0.8fr 0.8fr 1fr;
  gap:40px;
}

.footer-brand-link{
  padding:0;
  margin-bottom:12px;
}

.footer-brand-link:hover{
  background:transparent;
}

.trust-statement{
  font-size:14px;
  color:var(--color-text-muted);
  line-height:1.7;
  margin-top:8px;
  border-left:2px solid var(--color-accent-a);
  padding-left:12px;
}

.footer-heading{
  font-family:var(--font-head);
  font-size:15px;
  font-weight:700;
  text-transform:uppercase;
  letter-spacing:0.05em;
  color:var(--color-text);
  margin-bottom:16px;
  padding-bottom:8px;
  border-bottom:1px solid var(--color-border);
}

.footer-nav{
  list-style:none;
}

.footer-nav li{
  margin-bottom:6px;
}

.footer-nav a{
  color:var(--color-text-muted);
  font-size:14px;
  transition:color var(--transition-fast), padding-left var(--transition-base);
}

.footer-nav a:hover{
  color:var(--color-accent-b);
  padding-left:8px;
  text-decoration:none;
}

.contact-info{
  font-family:var(--font-sans);
  font-style:normal;
  display:flex;
  flex-direction:column;
  gap:8px;
  font-size:14px;
  color:var(--color-text-muted);
}

.contact-info a{
  color:var(--color-text-muted);
}

.contact-info a:hover{
  color:var(--color-accent-b);
}

.footer-bottom{
  max-width:1100px;
  margin:48px auto 0 auto;
  padding-top:20px;
  border-top:1px solid var(--color-border);
  display:flex;
  justify-content:space-between;
  flex-wrap:wrap;
  gap:8px;
  font-family:var(--font-mono);
  font-size:12px;
  color:var(--color-text-muted);
}

.footer-icp{
  letter-spacing:0.05em;
}

.back-top-link{
  position:fixed;
  right:24px;
  bottom:24px;
  width:48px;
  height:48px;
  background:var(--color-neon-gradient);
  border-radius:50%;
  display:flex;
  align-items:center;
  justify-content:center;
  color:var(--color-bg);
  font-size:20px;
  font-weight:900;
  opacity:0;
  pointer-events:none;
  transform:translateY(16px);
  transition:opacity var(--transition-base), transform var(--transition-base);
  box-shadow:0 0 20px rgba(229,54,138,0.3);
}

.back-top-link[data-top="visible"]{
  opacity:1;
  pointer-events:auto;
  transform:translateY(0);
}

.back-top-link:hover{
  text-decoration:none;
  color:var(--color-bg);
}

@media(prefers-reduced-motion:reduce){
  .back-top-link{
    transition:none;
  }
}

@media(max-width:1200px){
  :root{
    --header-width:240px;
  }
}

@media(max-width:992px){
  .site-shell{
    display:block;
  }

  .nav-frame{
    position:fixed;
    width:100%;
    height:auto;
    bottom:auto;
    top:0;
    border-right:none;
    border-bottom:1px solid var(--color-border);
    background:var(--color-surface);
    backdrop-filter:blur(12px);
    z-index:1000;
  }

  .nav-inner{
    padding:16px 20px;
    padding-right:80px;
    flex-direction:row;
    align-items:center;
    height:auto;
    gap:16px;
  }

  .brand-mark{
    padding:0;
    flex-shrink:0;
  }

  .brand-glyph{
    width:36px;
    height:36px;
    border-radius:12px;
  }

  .brand-name{
    font-size:18px;
  }

  .brand-slogan{
    display:none;
  }

  .nav-toggle{
    display:flex;
  }

  .primary-nav{
    display:none;
    position:absolute;
    top:100%;
    left:0;
    right:0;
    background:var(--color-surface);
    border-bottom:1px solid var(--color-border);
    padding:16px 20px;
    margin:0;
    max-height:80vh;
    overflow-y:auto;
    box-shadow:0 20px 30px rgba(0,0,0,0.4);
  }

  .nav-frame[data-open="true"] .primary-nav{
    display:block;
  }

  .nav-list{
    flex-direction:column;
  }

  .nav-search-item{
    border-top:1px solid var(--color-border);
    margin-top:12px;
    padding-top:12px;
  }

  .status-strip{
    display:none;
  }

  .content-container{
    padding:96px 24px 48px 24px;
    max-width:100%;
  }

  .site-footer{
    padding:40px 24px 20px 24px;
  }

  .footer-grid{
    grid-template-columns:1fr 1fr;
    gap:32px;
  }
}

@media(max-width:640px){
  .nav-inner{
    padding:12px 16px;
    padding-right:72px;
  }

  .brand-glyph{
    width:32px;
    height:32px;
    border-radius:10px;
  }

  .brand-name{
    font-size:16px;
  }

  .page-title{
    font-size:40px;
  }

  .page-description{
    font-size:15px;
  }

  .content-container{
    padding:88px 16px 32px 16px;
  }

  .grid-2,
  .grid-3{
    grid-template-columns:1fr;
  }

  .footer-grid{
    grid-template-columns:1fr;
    gap:28px;
  }

  .footer-bottom{
    flex-direction:column;
    align-items:flex-start;
  }

  .back-top-link{
    right:16px;
    bottom:16px;
  }

  .footer-contact .contact-info a{
    word-break:break-all;
  }
}

@media(max-width:360px){
  .brand-text .brand-name{
    font-size:14px;
  }

  .brand-glyph{
    width:28px;
    height:28px;
    border-radius:8px;
  }
}