/* ===== 重置与基础 ===== */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;font-size:16px;line-height:1.5;-webkit-text-size-adjust:100%;text-size-adjust:100%}
body{font-family:'Inter',system-ui,-apple-system,'Segoe UI',Roboto,Helvetica,Arial,sans-serif;font-weight:400;color:#FFFFFF;background:#0D0D0D;min-height:100vh;overflow-x:hidden}
img{display:block;max-width:100%;height:auto}
a{color:inherit;text-decoration:none}
ul,ol{list-style:none}
button{cursor:pointer;font:inherit;color:inherit;border:none;background:none}
:focus-visible{outline:2px solid #FFD700;outline-offset:2px;border-radius:2px}
::selection{background:#FF4500;color:#FFFFFF}

/* ===== CSS 变量 ===== */
:root{
  --color-primary:#FF4500;
  --color-secondary:#0A1F44;
  --color-accent:#FFD700;
  --color-bg-dark:#0D0D0D;
  --color-bg-light:#1A1A2E;
  --color-surface:#1C1C3A;
  --color-text:#FFFFFF;
  --color-text-secondary:#B0B0C0;
  --color-border:rgba(255,69,0,0.4);
  --color-success:#00FF7F;
  --color-error:#FF0040;
  --font-heading:'Bebas Neue','Impact','Arial Black',sans-serif;
  --font-body:'Inter',system-ui,-apple-system,'Segoe UI',Roboto,Helvetica,Arial,sans-serif;
  --font-data:'Bebas Neue','Courier New',monospace;
  --container-max:1200px;
  --header-z:100;
  --transition:0.3s cubic-bezier(0.4,0,0.2,1);
  --shadow-neon:0 0 12px rgba(255,69,0,0.3),0 0 24px rgba(255,69,0,0.1);
}

/* ===== 辅助类 ===== */
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.skip-link{position:absolute;top:-100%;left:0;z-index:200;padding:12px 24px;background:#FF4500;color:#FFFFFF;font-weight:600;font-size:0.9rem;transition:top 0.25s}
.skip-link:focus{top:0;outline:2px solid #FFD700;outline-offset:-2px}

/* ===== 容器 ===== */
.container{max-width:var(--container-max);margin:0 auto;padding:0 24px;width:100%}

/* ===== 按钮 ===== */
.btn{display:inline-flex;align-items:center;justify-content:center;padding:10px 24px;font-family:var(--font-heading);font-size:1.05rem;font-weight:bold;letter-spacing:0.08em;text-transform:uppercase;border-radius:4px;transition:all var(--transition);position:relative;overflow:hidden;background:var(--color-primary);color:#FFFFFF;border:2px solid var(--color-primary)}
.btn:hover{box-shadow:var(--shadow-neon);transform:translateY(-1px)}
.btn:active{transform:translateY(1px);box-shadow:0 0 6px rgba(255,69,0,0.5)}
.btn--outline{background:transparent;border-color:var(--color-border);color:var(--color-primary)}
.btn--outline:hover{background:rgba(255,69,0,0.12);border-color:var(--color-primary);box-shadow:var(--shadow-neon)}

/* ===== 卡片 ===== */
.card{background:var(--color-surface);border:1px solid var(--color-border);border-radius:6px;padding:24px;box-shadow:0 4px 20px rgba(0,0,0,0.4);transition:border-color var(--transition),box-shadow var(--transition)}
.card:hover{border-color:var(--color-primary);box-shadow:0 4px 28px rgba(255,69,0,0.15)}

/* ===== 分区标题 ===== */
.section-title{font-family:var(--font-heading);font-size:clamp(1.6rem,3.5vw,2.8rem);font-weight:bold;letter-spacing:0.05em;text-transform:uppercase;color:var(--color-text);position:relative;padding-bottom:12px;margin-bottom:28px}
.section-title::after{content:'';position:absolute;bottom:0;left:0;width:60px;height:4px;background:linear-gradient(90deg,var(--color-primary),var(--color-accent));border-radius:2px}

/* ===== 头部 ===== */
.site-header{
  position:relative;
  z-index:var(--header-z);
  background:linear-gradient(180deg,#0D0D0D 0%,#1A1A2E 100%);
  border-bottom:1px solid var(--color-border);
  padding:0 24px;
}
.header__inner{max-width:var(--container-max);margin:0 auto;padding:16px 0 12px}
.header__top{display:flex;align-items:center;justify-content:space-between;gap:16px;margin-bottom:10px}
.header__brand{display:flex;flex-direction:column;gap:2px}
.brand__name{font-family:var(--font-heading);font-size:clamp(1.8rem,4vw,3.2rem);font-weight:bold;letter-spacing:0.06em;text-transform:uppercase;color:var(--color-primary);text-shadow:0 0 18px rgba(255,69,0,0.35),0 0 48px rgba(255,69,0,0.12);line-height:1}
.brand__tagline{font-family:var(--font-body);font-size:clamp(0.7rem,1.2vw,0.85rem);font-weight:500;color:var(--color-text-secondary);letter-spacing:0.15em;text-transform:uppercase}
.header__actions{display:flex;align-items:center;gap:12px;flex-shrink:0}
.header__cta{padding:8px 18px;font-size:0.8rem;white-space:nowrap}
.header__toggle{display:none;width:40px;height:40px;align-items:center;justify-content:center;border:1px solid rgba(255,255,255,0.15);border-radius:4px;transition:border-color var(--transition)}
.header__toggle:hover{border-color:var(--color-primary)}
.toggle__icon{display:block;width:22px;height:2px;background:var(--color-text);position:relative;transition:background var(--transition)}
.toggle__icon::before,.toggle__icon::after{content:'';position:absolute;left:0;width:100%;height:2px;background:var(--color-text);transition:all var(--transition)}
.toggle__icon::before{top:-7px}
.toggle__icon::after{top:7px}
.header__toggle[aria-expanded="true"] .toggle__icon{background:transparent}
.header__toggle[aria-expanded="true"] .toggle__icon::before{top:0;transform:rotate(45deg);background:var(--color-primary)}
.header__toggle[aria-expanded="true"] .toggle__icon::after{top:0;transform:rotate(-45deg);background:var(--color-primary)}
.header__bottom{display:flex;align-items:center}
.header__nav{display:flex;flex-wrap:wrap;gap:4px;align-items:center}
.nav__link{
  font-family:var(--font-heading);
  font-size:1rem;
  font-weight:bold;
  letter-spacing:0.08em;
  text-transform:uppercase;
  color:var(--color-text-secondary);
  padding:6px 16px;
  border-radius:4px;
  transition:all var(--transition);
  position:relative;
  white-space:nowrap;
}
.nav__link::after{content:'';position:absolute;bottom:0;left:50%;transform:translateX(-50%);width:0;height:2px;background:var(--color-primary);transition:width var(--transition)}
.nav__link:hover,.nav__link:focus-visible{color:var(--color-primary);text-shadow:0 0 12px rgba(255,69,0,0.25)}
.nav__link:hover::after,.nav__link:focus-visible::after{width:60%}
.nav__link[aria-current="page"]{color:var(--color-primary)}
.nav__link[aria-current="page"]::after{width:60%;background:var(--color-accent);box-shadow:0 0 8px rgba(255,215,0,0.4)}

/* ===== 滚动进度条 ===== */
.header__progress{position:fixed;top:0;left:0;width:0%;height:3px;background:linear-gradient(90deg,var(--color-primary),var(--color-accent));z-index:calc(var(--header-z) + 10);transition:width 0.1s linear;box-shadow:0 0 12px rgba(255,69,0,0.5);pointer-events:none}

/* ===== 页脚 ===== */
.site-footer{
  background:linear-gradient(180deg,#1A1A2E 0%,#0D0D0D 100%);
  border-top:1px solid var(--color-border);
  padding:40px 24px 24px;
  margin-top:60px;
}
.footer__inner{max-width:var(--container-max);margin:0 auto}
.footer__main{display:flex;flex-wrap:wrap;justify-content:space-between;gap:32px;padding-bottom:24px}
.footer__brand{flex:2;min-width:260px}
.footer__logo{font-family:var(--font-heading);font-size:1.8rem;font-weight:bold;letter-spacing:0.06em;text-transform:uppercase;color:var(--color-primary);text-shadow:0 0 14px rgba(255,69,0,0.25);display:block;margin-bottom:8px}
.footer__desc{font-size:0.9rem;line-height:1.7;color:var(--color-text-secondary);max-width:420px}
.footer__nav{flex:1;min-width:180px;display:flex;flex-direction:column;gap:12px;align-items:flex-start;padding-top:6px}
.footer__link{font-family:var(--font-heading);font-size:0.95rem;font-weight:bold;letter-spacing:0.06em;text-transform:uppercase;color:var(--color-text-secondary);padding:4px 0;transition:color var(--transition);position:relative}
.footer__link::after{content:'';position:absolute;bottom:0;left:0;width:0;height:2px;background:var(--color-primary);transition:width var(--transition)}
.footer__link:hover,.footer__link:focus-visible{color:var(--color-primary)}
.footer__link:hover::after,.footer__link:focus-visible::after{width:100%}
.footer__divider{height:1px;background:linear-gradient(90deg,transparent,var(--color-border),transparent);margin:0 0 20px}
.footer__bottom{display:flex;flex-direction:column;gap:10px;padding-top:4px}
.footer__legal{display:flex;flex-wrap:wrap;gap:16px 28px;align-items:center;font-size:0.8rem;color:var(--color-text-secondary)}
.footer__copyright{font-weight:500;color:rgba(255,255,255,0.65)}
.footer__icp{color:rgba(255,255,255,0.45);font-size:0.75rem;letter-spacing:0.04em}
.footer__contact{color:var(--color-text-secondary);font-size:0.8rem}
.footer__email{color:var(--color-accent);transition:color var(--transition)}
.footer__email:hover{color:var(--color-primary);text-decoration:underline}
.footer__note{font-size:0.75rem;color:rgba(255,255,255,0.35);line-height:1.5;margin-top:4px}
.footer__note::before{content:'⚡ ';color:var(--color-accent)}

/* ===== 移动端头部 ===== */
@media(max-width:768px){
  .header__top{padding-bottom:6px;margin-bottom:0}
  .header__toggle{display:flex}
  .header__bottom{position:relative}
  .header__nav{
    position:absolute;top:100%;left:0;right:0;flex-direction:column;gap:0;
    background:linear-gradient(180deg,#1A1A2E,#0D0D0D);
    border:1px solid var(--color-border);
    border-top:none;border-radius:0 0 6px 6px;
    padding:8px 0;opacity:0;visibility:hidden;
    transform:translateY(-8px);transition:all var(--transition);
    pointer-events:none;
  }
  .header__nav[data-open]{opacity:1;visibility:visible;transform:translateY(0);pointer-events:auto}
  .nav__link{width:100%;padding:12px 20px;font-size:1.05rem;border-radius:0;border-bottom:1px solid rgba(255,255,255,0.05)}
  .nav__link:last-child{border-bottom:none}
  .nav__link::after{display:none}
  .nav__link[aria-current="page"]{background:rgba(255,69,0,0.1);color:var(--color-primary)}
  .header__cta{font-size:0.7rem;padding:6px 14px}
}

@media(min-width:769px){
  .header__nav{flex-direction:row;opacity:1;visibility:visible;transform:none;pointer-events:auto;position:static;background:none;border:none;padding:0}
  .header__nav[data-open]{transform:none}
}

/* ===== 平板适配 ===== */
@media(max-width:1024px) and (min-width:769px){
  .header__top{flex-wrap:wrap}
  .brand__name{font-size:2rem}
  .nav__link{font-size:0.85rem;padding:6px 12px;letter-spacing:0.06em}
  .header__cta{font-size:0.75rem;padding:6px 14px}
}

/* ===== 页脚响应式 ===== */
@media(max-width:640px){
  .footer__main{flex-direction:column;gap:24px}
  .footer__nav{flex-direction:row;flex-wrap:wrap;gap:8px 20px;padding-top:0}
  .footer__link{font-size:0.85rem}
  .footer__legal{flex-direction:column;gap:6px;align-items:flex-start}
  .footer__contact{font-size:0.75rem;word-break:break-all}
  .site-footer{padding:28px 16px 20px}
}

@media(min-width:641px) and (max-width:1024px){
  .footer__brand{flex:1.5;min-width:200px}
  .footer__nav{min-width:140px}
}

/* ===== 动效偏好 ===== */
@media(prefers-reduced-motion:reduce){
  *,*::before,*::after{transition-duration:0.01ms!important;animation-duration:0.01ms!important;animation-iteration-count:1!important;scroll-behavior:auto!important}
  .header__progress{display:none}
}

/* ===== 图片容器基础 ===== */
.img-frame{background:var(--color-surface);border:1px solid var(--color-border);border-radius:4px;overflow:hidden;position:relative;min-height:120px}
.img-frame::before{content:'';display:block;padding-bottom:56.25%}
.img-frame img{position:absolute;top:0;left:0;width:100%;height:100%;object-fit:cover}
.img-frame--tall::before{padding-bottom:120%}
.img-frame--square::before{padding-bottom:100%}
.img-frame--wide::before{padding-bottom:40%}

/* ===== 网格系统 ===== */
.grid{display:grid;gap:24px}
.grid--2{grid-template-columns:repeat(2,1fr)}
.grid--3{grid-template-columns:repeat(3,1fr)}
.grid--4{grid-template-columns:repeat(4,1fr)}
@media(max-width:768px){
  .grid--2,.grid--3,.grid--4{grid-template-columns:1fr}
}
@media(min-width:769px) and (max-width:1024px){
  .grid--3{grid-template-columns:repeat(2,1fr)}
  .grid--4{grid-template-columns:repeat(2,1fr)}
}

/* ===== 常用间距 ===== */
.mt-1{margin-top:8px}
.mt-2{margin-top:16px}
.mt-3{margin-top:24px}
.mt-4{margin-top:32px}
.mt-5{margin-top:48px}
.mb-1{margin-bottom:8px}
.mb-2{margin-bottom:16px}
.mb-3{margin-bottom:24px}
.mb-4{margin-bottom:32px}
.mb-5{margin-bottom:48px}
.p-1{padding:8px}
.p-2{padding:16px}
.p-3{padding:24px}
.p-4{padding:32px}

/* ===== 数据数字 ===== */
.data-number{font-family:var(--font-data);font-weight:bold;font-size:clamp(1.5rem,3vw,2.5rem);letter-spacing:0.02em;color:var(--color-accent);line-height:1}
.data-number--primary{color:var(--color-primary)}
.data-number--light{color:var(--color-text)}

/* ===== 标签 ===== */
.tag{display:inline-block;font-family:var(--font-body);font-weight:600;font-size:0.75rem;text-transform:uppercase;letter-spacing:0.08em;padding:3px 10px;border-radius:2px;background:rgba(255,69,0,0.15);color:var(--color-primary);border:1px solid rgba(255,69,0,0.25)}
.tag--live{background:rgba(0,255,127,0.12);color:var(--color-success);border-color:rgba(0,255,127,0.25);animation:pulse-live 2s ease-in-out infinite}
@keyframes pulse-live{0%,100%{opacity:1}50%{opacity:0.6}}

/* ===== 分隔线 ===== */
.divider-neon{height:1px;background:linear-gradient(90deg,transparent,var(--color-primary),var(--color-accent),var(--color-primary),transparent);margin:32px 0;opacity:0.4}