:root{
  --color-primary:#FF6F00;
  --color-success:#00C853;
  --color-danger:#E53935;
  --color-dark:#1E1E1E;
  --color-light:#F5F5F5;
  --color-gray:#9E9E9E;
  --color-info:#00E5FF;
  --color-purple:#7C4DFF;
  --font-display:"Arial Black","Impact","PingFang SC","Microsoft YaHei",sans-serif;
  --font-body:"PingFang SC","Microsoft YaHei","Varela Round",sans-serif;
  --container-width:1200px;
  --header-height:72px;
  --radius:12px;
  --space-xs:4px; --space-sm:8px; --space-md:16px; --space-lg:24px; --space-xl:48px;
  --transition:0.3s cubic-bezier(0.4,0,0.2,1);
  --shadow:0 4px 24px rgba(0,0,0,0.4);
}
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  font-family:var(--font-body);
  background:var(--color-dark);
  color:var(--color-light);
  line-height:1.6;
  min-height:100vh;
}
img{max-width:100%;display:block}
a{color:var(--color-light);text-decoration:none}
a:hover{color:var(--color-primary)}
ul{list-style:none}
:focus-visible{outline:3px solid var(--color-info);outline-offset:2px;border-radius:4px}
button{font-family:inherit;cursor:pointer;border:none;background:none}
.container{width:min(100% - 3rem, var(--container-width));margin-inline:auto}
.skip-link{
  position:fixed;top:-100px;left:1rem;z-index:2000;
  background:var(--color-primary);color:var(--color-dark);
  font-weight:900;padding:.5rem 1rem;border-radius:0 0 8px 8px;
  transition:top var(--transition);
}
.skip-link:focus{top:0}
.site-header{
  position:fixed;top:0;left:0;right:0;z-index:1000;
  height:var(--header-height);
  background:linear-gradient(to bottom, rgba(30,30,30,0.8), transparent);
  transition:background var(--transition), box-shadow var(--transition);
}
.site-header[data-scrolled="true"]{
  background:rgba(30,30,30,0.95);
  box-shadow:0 2px 20px rgba(0,0,0,0.6), 0 1px 0 rgba(255,111,0,0.4);
  backdrop-filter:blur(10px);
}
.header-inner{display:flex;align-items:center;justify-content:space-between;gap:1rem;height:100%;position:relative}
.brand{display:flex;align-items:center;gap:.75rem;transform:skewX(-8deg);flex-shrink:0}
.brand-mark{
  display:grid;place-items:center;width:44px;height:44px;
  background:var(--color-primary);color:var(--color-dark);
  font-weight:900;font-size:1.5rem;border-radius:8px;
  box-shadow:0 0 12px rgba(255,111,0,0.5);
}
.brand-text{display:flex;flex-direction:column;line-height:1.1}
.brand-name{font-family:var(--font-display);font-weight:900;font-size:1.25rem;letter-spacing:.5px}
.brand-name strong{color:var(--color-primary);font-size:1.4em;margin-left:2px}
.brand-tagline{font-size:.65rem;letter-spacing:2px;color:var(--color-gray);text-transform:uppercase}
.site-nav ul{display:flex;gap:2px}
.site-nav a{
  display:block;padding:.6rem .9rem;font-weight:700;font-size:.95rem;
  border-radius:6px;position:relative;transition:color .2s;
}
.site-nav a:hover{color:var(--color-primary)}
.site-nav a[aria-current="page"]{
  color:var(--color-primary);
}
.site-nav a[aria-current="page"]::after{
  content:"";position:absolute;left:.6rem;right:.6rem;bottom:0;height:3px;
  background:var(--color-primary);transform:skewX(-20deg);
  box-shadow:0 0 8px var(--color-primary);
}
.nav-toggle{
  display:none;width:44px;height:44px;flex-direction:column;
  justify-content:center;align-items:center;gap:5px;border-radius:8px;
  border:1px solid rgba(255,255,255,0.2);background:rgba(30,30,30,0.6);
}
.nav-toggle span{display:block;width:22px;height:2px;background:var(--color-light);transition:transform .3s, opacity .3s}
.nav-toggle[aria-expanded="true"] span:nth-child(1){transform:translateY(7px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] span:nth-child(2){opacity:0}
.nav-toggle[aria-expanded="true"] span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}
.scroll-progress{position:absolute;left:0;right:0;bottom:0;height:3px;background:rgba(255,255,255,0.08)}
#scroll-progress-bar{display:block;height:100%;width:0%;background:linear-gradient(90deg,var(--color-primary),var(--color-danger));box-shadow:0 0 10px var(--color-primary);transition:width .2s ease}
.page-hero{min-height:100vh;display:flex;align-items:center;padding:calc(var(--header-height) + 3rem) 0 3rem;position:relative;overflow:hidden}
.diagonal-clip{clip-path:polygon(0 0,100% 0,100% 100%,0 85%)}
.chapter-number{
  font-family:var(--font-display);font-weight:900;font-size:clamp(3rem,10vw,7rem);line-height:1;
  color:transparent;-webkit-text-stroke:2px var(--color-primary);
  letter-spacing:-2px;
}
.chapter-title{font-family:var(--font-display);font-weight:900;font-size:clamp(1.5rem,4vw,2.5rem);line-height:1.2}
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:.5rem;
  padding:.75rem 1.75rem;border-radius:8px;font-weight:800;font-size:1rem;
  transition:transform var(--transition), box-shadow var(--transition), background var(--transition);
}
.btn:hover{transform:translateY(-2px)}
.btn-primary{background:var(--color-primary);color:var(--color-dark);box-shadow:0 4px 14px rgba(255,111,0,0.4)}
.btn-primary:hover{background:#ff8c3a;box-shadow:0 6px 20px rgba(255,111,0,0.6)}
.btn-outline{border:2px solid var(--color-primary);color:var(--color-primary);background:transparent}
.btn-outline:hover{background:var(--color-primary);color:var(--color-dark)}
.breadcrumbs{display:flex;flex-wrap:wrap;gap:.5rem;padding:1rem 0;font-size:.9rem;color:var(--color-gray)}
.breadcrumbs a{color:var(--color-gray)}
.breadcrumbs a:hover{color:var(--color-primary)}
.breadcrumbs [aria-current="page"]{color:var(--color-light);font-weight:800}
.status-dot{display:inline-block;width:8px;height:8px;border-radius:50%;background:var(--color-success);box-shadow:0 0 8px var(--color-success);margin-right:.4rem;vertical-align:middle}
.status-live{animation:pulse 1.5s ease-in-out infinite}
@keyframes pulse{0%,100%{opacity:1}50%{opacity:.4}}
.figure-stacked,.figure-wide{border-radius:var(--radius);background:linear-gradient(135deg,#2a2a2a,#161616);border:1px solid rgba(255,255,255,0.08);overflow:hidden;min-height:180px;display:grid;place-items:center;color:var(--color-gray);position:relative}
.figure-wide{min-height:260px}
.figure-stacked::before,.figure-wide::before{content:"视觉图片区";font-weight:700;letter-spacing:2px;font-size:.8rem;color:var(--color-gray)}
.site-footer{background:#141414;border-top:4px solid var(--color-primary);position:relative;margin-top:6rem}
.site-footer::before{content:"";position:absolute;top:-4px;left:0;width:100%;height:4px;background:repeating-linear-gradient(90deg,var(--color-primary) 0 40px,var(--color-danger) 40px 80px)}
.footer-grid{display:grid;grid-template-columns:1.6fr .8fr 1.2fr .8fr;gap:3rem;padding:4rem 0 2rem}
.footer-logo{font-family:var(--font-display);font-weight:900;font-size:1.8rem;transform:skewX(-6deg)}
.footer-logo strong{color:var(--color-primary)}
.footer-slogan{color:var(--color-primary);font-weight:700;margin-top:.25rem;letter-spacing:1px}
.footer-trust{color:var(--color-gray);font-size:.9rem;margin-top:1.2rem;line-height:1.7;max-width:32ch}
.footer-title{font-weight:900;font-size:1.1rem;margin-bottom:1rem;position:relative;padding-bottom:.5rem}
.footer-title::after{content:"";position:absolute;bottom:0;left:0;width:32px;height:3px;background:var(--color-primary);transform:skewX(-20deg)}
.footer-nav ul,.footer-legal ul{display:flex;flex-direction:column;gap:.6rem}
.footer-nav a,.footer-legal a{color:var(--color-gray);transition:color .2s,padding-left .2s}
.footer-nav a:hover,.footer-legal a:hover{color:var(--color-primary);padding-left:.25rem}
.footer-contact p{color:var(--color-gray);margin-bottom:.6rem;font-size:.95rem;line-height:1.6}
.footer-contact a{color:var(--color-gray)}
.footer-contact a:hover{color:var(--color-primary)}
.footer-bottom{display:flex;flex-wrap:wrap;justify-content:space-between;align-items:center;padding:1.5rem 0;border-top:1px solid rgba(255,255,255,0.08);color:var(--color-gray);font-size:.85rem;gap:1rem}
.back-to-top{
  position:fixed;bottom:2rem;right:2rem;z-index:99;
  width:48px;height:48px;border-radius:10px;
  background:var(--color-primary);color:var(--color-dark);
  font-size:1.5rem;font-weight:900;
  display:grid;place-items:center;
  opacity:0;visibility:hidden;transform:translateY(12px);
  transition:opacity var(--transition), transform var(--transition), visibility var(--transition), box-shadow var(--transition);
  box-shadow:0 4px 16px rgba(255,111,0,0.4);
}
.back-to-top[data-visible="true"]{opacity:1;visibility:visible;transform:translateY(0)}
.back-to-top:hover{background:#ff8c3a;transform:translateY(-3px);box-shadow:0 8px 24px rgba(255,111,0,0.6)}
@media (max-width:1024px){
  .footer-grid{grid-template-columns:1fr 1fr;gap:2rem}
}
@media (max-width:768px){
  :root{--header-height:64px}
  .nav-toggle{display:flex}
  .site-nav{
    position:fixed;top:0;right:-100%;width:min(72vw,320px);height:100vh;
    background:var(--color-dark);flex-direction:column;padding:calc(var(--header-height) + 1rem) 1.5rem 2rem;
    transition:right .3s ease;box-shadow:-8px 0 24px rgba(0,0,0,0.5);
    border-left:1px solid var(--color-primary);
  }
  .site-nav[data-open="true"]{right:0}
  .site-nav ul{flex-direction:column;gap:.25rem}
  .site-nav a{font-size:1.1rem;padding:.9rem 1rem}
  .site-nav a[aria-current="page"]::after{top:.5rem;bottom:.5rem;right:auto;left:0;width:4px;height:auto}
  .header-inner{padding:0 1rem}
  .brand-mark{width:38px;height:38px;font-size:1.2rem}
  .brand-name{font-size:1.1rem}
  .brand-tagline{display:none}
  .page-hero{padding-top:calc(var(--header-height) + 2rem)}
  .footer-grid{grid-template-columns:1fr;padding-top:2rem}
  .footer-bottom{flex-direction:column;text-align:center}
  .container{width:min(100% - 2rem, var(--container-width))}
  .back-to-top{bottom:1.5rem;right:1.5rem;width:44px;height:44px}
}
@media (prefers-reduced-motion: reduce){
  *{animation-duration:0.01ms !important;animation-iteration-count:1 !important;transition-duration:0.01ms !important}
  html{scroll-behavior:auto}
  .site-nav{transition:none}
  .back-to-top{transition:opacity .2s}
}