*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{
  --color-primary:#FF6600;
  --color-primary-dark:#CC5500;
  --color-bg-dark:#0A1628;
  --color-bg-medium:#1A2A40;
  --color-accent-green:#39FF14;
  --color-silver:#C0C0C0;
  --color-white:#FFFFFF;
  --color-text-secondary:#B0B0B0;
  --gradient-bg:linear-gradient(135deg,#0A1628,#1A2A40);
  --gradient-orange:linear-gradient(135deg,#FF6600,#CC5500);
  --font-heading:Montserrat,'Arial Black','Arial',sans-serif;
  --font-body:'Source Sans Pro','Segoe UI','Arial',sans-serif;
  --container-max:1200px;
  --header-height:72px;
  --slash-height:8px;
  --transition-fast:0.2s ease;
  --transition-medium:0.35s ease;
  --shadow-card:0 4px 24px rgba(0,0,0,0.3)
}
html{scroll-behavior:smooth;font-size:16px}
body{font-family:var(--font-body);background:var(--color-bg-dark);color:var(--color-white);line-height:1.6;-webkit-font-smoothing:antialiased}
::selection{background:var(--color-primary);color:var(--color-white)}
:focus-visible{outline:2px solid var(--color-primary);outline-offset:2px;border-radius:2px}
.skip-link{position:absolute;top:-100%;left:1rem;padding:0.5rem 1rem;background:var(--color-primary);color:var(--color-white);z-index:9999;font-weight:700;text-decoration:none;border-radius:0 0 4px 4px;transition:top var(--transition-fast)}
.skip-link:focus{top:0}
.container{max-width:var(--container-max);margin:0 auto;padding-left:1.5rem;padding-right:1.5rem}
/* 头部 ===== */
.site-header{position:relative;background:var(--color-bg-dark);border-bottom:1px solid rgba(192,192,192,0.12);z-index:100}
.site-header::after{content:'';display:block;height:var(--slash-height);background:var(--gradient-orange);clip-path:polygon(0 0,100% 0,100% 100%,0 70%);position:relative;z-index:1}
.header__inner{display:flex;align-items:center;justify-content:space-between;height:var(--header-height);gap:1rem}
.brand{display:flex;align-items:baseline;gap:0.5rem;flex-shrink:0}
.brand__name{font-family:var(--font-heading);font-size:1.5rem;font-weight:800;color:var(--color-white);letter-spacing:-0.02em;text-transform:uppercase}
.brand__tag{font-family:var(--font-heading);font-size:0.85rem;font-weight:600;color:var(--color-primary);letter-spacing:0.1em;text-transform:uppercase;display:none}
@media(min-width:640px){.brand__tag{display:inline}}
/* 导航 ===== */
.site-nav{flex:1;display:none}
.site-nav[data-open]{display:block;position:fixed;top:var(--header-height);left:0;right:0;bottom:0;background:rgba(10,22,40,0.98);padding:2rem 1.5rem;overflow-y:auto;z-index:200}
.site-nav__list{list-style:none;counter-reset:nav-index;display:flex;flex-direction:column;gap:0.25rem}
.site-nav__item{counter-increment:nav-index}
.site-nav__link{display:flex;align-items:center;gap:0.75rem;padding:0.75rem 1rem;font-family:var(--font-heading);font-size:1.1rem;font-weight:600;color:var(--color-text-secondary);text-decoration:none;border-radius:4px;transition:color var(--transition-fast),background var(--transition-fast);position:relative}
.site-nav__link::before{content:counter(nav-index);font-size:0.7rem;font-weight:700;color:var(--color-silver);opacity:0.5;width:1.8rem;text-align:right;flex-shrink:0;font-variant-numeric:tabular-nums}
.site-nav__link:hover,.site-nav__link:focus-visible{color:var(--color-white);background:rgba(255,102,0,0.08)}
.site-nav__link[aria-current="page"]{color:var(--color-primary);background:rgba(255,102,0,0.12)}
.site-nav__link[aria-current="page"]::before{color:var(--color-primary);opacity:1}
@media(min-width:1024px){
  .site-nav{display:flex;align-items:center;justify-content:center}
  .site-nav[data-open]{position:static;background:transparent;padding:0;overflow:visible}
  .site-nav__list{flex-direction:row;gap:0.125rem}
  .site-nav__link{padding:0.5rem 1rem;font-size:0.9rem}
  .site-nav__link::before{content:counter(nav-index,decimal-leading-zero);font-size:0.6rem;width:1.6rem}
}
/* 导航切换按钮 ===== */
.nav-toggle{display:flex;align-items:center;justify-content:center;width:44px;height:44px;background:transparent;border:1px solid var(--color-silver);border-radius:4px;cursor:pointer;color:var(--color-white);transition:border-color var(--transition-fast),background var(--transition-fast);flex-shrink:0}
.nav-toggle:hover,.nav-toggle:focus-visible{border-color:var(--color-primary);background:rgba(255,102,0,0.1)}
.nav-toggle__icon{display:block;width:22px;height:2px;background:var(--color-white);position:relative;transition:background var(--transition-fast)}
.nav-toggle__icon::before,.nav-toggle__icon::after{content:'';display:block;width:22px;height:2px;background:var(--color-white);position:absolute;left:0;transition:transform var(--transition-fast),top var(--transition-fast),bottom var(--transition-fast)}
.nav-toggle__icon::before{top:-7px}
.nav-toggle__icon::after{bottom:-7px}
.nav-toggle[aria-expanded="true"] .nav-toggle__icon{background:transparent}
.nav-toggle[aria-expanded="true"] .nav-toggle__icon::before{top:0;transform:rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle__icon::after{bottom:0;transform:rotate(-45deg)}
@media(min-width:1024px){.nav-toggle{display:none}}
/* 头部动作区 ===== */
.header__actions{display:flex;align-items:center;gap:0.75rem;flex-shrink:0}
.header__cta{white-space:nowrap}
/* 按钮 ===== */
.btn{display:inline-flex;align-items:center;justify-content:center;padding:0.6rem 1.5rem;font-family:var(--font-heading);font-size:0.9rem;font-weight:700;text-decoration:none;border-radius:4px;border:2px solid transparent;cursor:pointer;transition:all var(--transition-fast);min-height:44px}
.btn--primary{background:var(--color-primary);color:var(--color-white);border-color:var(--color-primary)}
.btn--primary:hover,.btn--primary:focus-visible{background:var(--color-primary-dark);border-color:var(--color-primary-dark);transform:translateY(-1px);box-shadow:0 4px 16px rgba(255,102,0,0.3)}
.btn--secondary{background:transparent;color:var(--color-white);border-color:var(--color-silver)}
.btn--secondary:hover,.btn--secondary:focus-visible{border-color:var(--color-primary);color:var(--color-primary);background:rgba(255,102,0,0.06)}
/* 页脚 ===== */
.site-footer{position:relative;background:var(--color-bg-dark);border-top:1px solid rgba(192,192,192,0.1);margin-top:4rem}
.site-footer::before{content:'';display:block;height:var(--slash-height);background:var(--gradient-orange);clip-path:polygon(0 30%,100% 0,100% 100%,0 100%);position:relative;z-index:1;margin-bottom:0}
.footer__inner{padding-top:3rem;padding-bottom:2.5rem;display:grid;grid-template-columns:1fr;gap:2.5rem}
.footer__brand .brand{margin-bottom:0.75rem}
.footer__trust{font-size:0.9rem;color:var(--color-text-secondary);max-width:36rem;line-height:1.5}
.footer__nav{display:flex;flex-wrap:wrap;gap:0.5rem 1.5rem}
.footer__link{font-size:0.9rem;color:var(--color-text-secondary);text-decoration:none;padding:0.25rem 0;border-bottom:1px solid transparent;transition:color var(--transition-fast),border-color var(--transition-fast)}
.footer__link:hover,.footer__link:focus-visible{color:var(--color-primary);border-bottom-color:var(--color-primary)}
.footer__contact{display:flex;flex-direction:column;gap:0.4rem;font-size:0.85rem;color:var(--color-text-secondary)}
.footer__contact-item{display:inline}
.footer__meta{display:flex;flex-direction:column;gap:0.5rem;padding-top:1.5rem;border-top:1px solid rgba(192,192,192,0.15);font-size:0.8rem;color:var(--color-text-secondary)}
.footer__copyright{color:var(--color-silver)}
.footer__icp{color:var(--color-text-secondary);font-family:var(--font-body)}
@media(min-width:640px){
  .footer__inner{grid-template-columns:2fr 1fr;gap:2rem 3rem}
  .footer__meta{grid-column:1/-1;flex-direction:row;justify-content:space-between;align-items:center}
}
@media(min-width:1024px){
  .footer__inner{grid-template-columns:2fr 1fr 1fr;padding-top:4rem}
  .footer__meta{grid-column:1/-1}
}
/* 通用组件 ===== */
.grid{display:grid;grid-template-columns:1fr;gap:2rem}
@media(min-width:640px){.grid--2{grid-template-columns:1fr 1fr}}
@media(min-width:1024px){.grid--3{grid-template-columns:1fr 1fr 1fr}}
.tag{display:inline-flex;align-items:center;padding:0.2rem 0.8rem;font-size:0.75rem;font-weight:600;font-family:var(--font-heading);color:var(--color-silver);border:1px solid var(--color-silver);border-radius:2px;text-transform:uppercase;letter-spacing:0.05em;background:transparent}
.tag--primary{border-color:var(--color-primary);color:var(--color-primary)}
.tag--green{border-color:var(--color-accent-green);color:var(--color-accent-green)}
/* 印刷边框装饰（用于页脚品牌） ===== */
.footer__brand .brand{padding:1rem;border:1px solid rgba(192,192,192,0.2);display:inline-flex;position:relative}
.footer__brand .brand::after{content:'';position:absolute;top:4px;left:4px;right:-4px;bottom:-4px;border:1px solid rgba(192,192,192,0.08);pointer-events:none}
/* 滚动显现 ===== */
.reveal{opacity:0;transform:translateY(24px);transition:opacity 0.5s ease,transform 0.5s ease}
.reveal--visible{opacity:1;transform:translateY(0)}
/* reduced-motion ===== */
@media(prefers-reduced-motion:reduce){
  *,*::before,*::after{animation-duration:0.01ms!important;animation-iteration-count:1!important;transition-duration:0.01ms!important;scroll-behavior:auto!important}
  .reveal{opacity:1;transform:none;transition:none}
  html{scroll-behavior:auto}
}
/* 返回顶部按钮 ===== */
.back-to-top{position:fixed;bottom:2rem;right:2rem;width:48px;height:48px;border-radius:50%;background:var(--color-primary);color:var(--color-white);border:none;cursor:pointer;display:flex;align-items:center;justify-content:center;font-size:1.4rem;box-shadow:0 4px 16px rgba(255,102,0,0.3);opacity:0;visibility:hidden;transform:translateY(12px);transition:opacity var(--transition-medium),visibility var(--transition-medium),transform var(--transition-medium),background var(--transition-fast);z-index:999}
.back-to-top.is-visible{opacity:1;visibility:visible;transform:translateY(0)}
.back-to-top:hover,.back-to-top:focus-visible{background:var(--color-primary-dark);transform:translateY(-2px)}
.back-to-top:focus-visible{outline:2px solid var(--color-white);outline-offset:2px}
/* 占位图片容器规则（供页面阶段使用） ===== */
.img-placeholder{display:block;width:100%;background:var(--color-bg-medium);position:relative;overflow:hidden;aspect-ratio:16/9}
.img-placeholder::after{content:'🎮';position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);font-size:2rem;opacity:0.3}
/* 基础正文容器 ===== */
.content-section{padding:3rem 0}
.content-section+.content-section{border-top:1px solid rgba(192,192,192,0.08)}
.page-hero{padding:4rem 0 3rem;position:relative}
.page-hero::after{content:'';position:absolute;bottom:0;left:0;right:0;height:1px;background:linear-gradient(90deg,transparent,var(--color-primary),transparent);opacity:0.3}
/* 响应式微调 ===== */
@media(max-width:639px){
  .header__inner{height:60px}
  :root{--header-height:60px}
  .brand__name{font-size:1.2rem}
  .header__cta{padding:0.5rem 1rem;font-size:0.8rem}
  .footer__inner{padding-top:2rem;padding-bottom:1.5rem;gap:1.5rem}
}
@media(min-width:640px)and(max-width:1023px){
  .site-nav__link{font-size:1rem}
}
/* 导航链接序号统一修正 ===== */
.site-nav__link .site-nav__index{display:inline-flex;align-items:center;justify-content:flex-end;width:1.8rem;font-size:0.7rem;font-weight:700;color:var(--color-silver);opacity:0.5;flex-shrink:0;font-variant-numeric:tabular-nums}
.site-nav__link[aria-current="page"] .site-nav__index{color:var(--color-primary);opacity:1}