/* ============================================================
   贝斯特2255中文站 · 共享样式 /assets/site.css
   1 变量  2 reset  3 排版  4 通用组件  5 页头  6 页脚
   7 响应式  8 动效与可访问性
   ============================================================ */

/* 1. 变量 */
:root{
  --ink-950:#06131F;
  --ink-900:#0B1E2E;
  --rail-800:#123B5D;
  --signal:#FF6A2A;
  --signal-soft:#FFB18A;
  --sage:#9FB8A8;
  --sage-deep:#55766A;
  --mist:#F4F6F2;
  --snow:#FFFFFF;
  --text:#E9F0F5;
  --text-dim:#9AAAB8;
  --ok:#5FC2A0;

  --font-head:"Source Han Sans SC","Noto Sans SC","PingFang SC","Microsoft YaHei",sans-serif;
  --font-body:"Inter","Noto Sans SC","PingFang SC","Microsoft YaHei",sans-serif;
  --font-mono:"IBM Plex Mono","Roboto Mono",ui-monospace,SFMono-Regular,monospace;

  --radius-cap:24px;
  --radius-card:16px;
  --radius-pill:999px;

  --line-soft:rgba(159,184,168,.2);
  --line-strong:rgba(159,184,168,.38);
  --glass:rgba(11,30,46,.9);

  --shadow-cap:0 18px 46px rgba(2,8,14,.55);
  --shadow-float:0 12px 30px rgba(2,8,14,.45);
  --ease:cubic-bezier(.22,.61,.36,1);
  --gutter:clamp(16px,3.2vw,40px);
}

/* 2. reset */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body,h1,h2,h3,h4,p,ul,ol,figure,blockquote,dl,dd{margin:0}
ul,ol{padding:0;list-style:none}
img,svg,picture,video{display:block;max-width:100%}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer}
a{color:inherit;text-decoration:none}
table{border-collapse:collapse;width:100%}
[id]{scroll-margin-top:132px}

/* 3. 中文排版 */
body{
  min-height:100vh;
  font-family:var(--font-body);
  font-size:clamp(1rem,1.05vw,1.0625rem);
  line-height:1.78;
  color:var(--text);
  background:
    radial-gradient(1100px 620px at 84% -12%,rgba(18,59,93,.6),transparent 68%),
    radial-gradient(700px 400px at -10% 40%,rgba(18,59,93,.28),transparent 70%),
    var(--ink-950);
  background-attachment:fixed;
  -webkit-font-smoothing:antialiased;
}
h1,h2,h3,h4{
  font-family:var(--font-head);
  font-weight:800;
  line-height:1.16;
  letter-spacing:-.015em;
  color:var(--snow);
}
h1{font-size:clamp(2.4rem,4.8vw,4.8rem)}
h2{font-size:clamp(1.8rem,3vw,3rem)}
h3{font-size:clamp(1.25rem,1.8vw,1.75rem)}
h4{font-size:1.0625rem;letter-spacing:.01em}
p{max-width:72ch}
strong{font-weight:700;color:var(--snow)}
small{font-size:.8125rem}
::selection{background:var(--signal);color:var(--ink-950)}

/* 4. 通用组件 */
.container{
  width:100%;
  max-width:1280px;
  margin-inline:auto;
  padding-inline:var(--gutter);
}
.section{padding-block:clamp(32px,5vw,64px);
}
.section--mist{
  background:var(--mist);
  color:#12232F;
  border-radius:var(--radius-card);
}
.section--mist h2,.section--mist h3,.section--mist h4{color:#06131F}
.section--mist .lede{color:#2B4557}
.section-head{
  display:flex;
  flex-wrap:wrap;
  align-items:baseline;
  gap:10px 22px;
  padding-bottom:14px;
  margin-bottom:clamp(18px,2.6vw,30px);
  border-bottom:1px solid var(--line-soft);
}
.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:10px;
  font-family:var(--font-mono);
  font-size:.6875rem;
  letter-spacing:.18em;
  text-transform:uppercase;
  color:var(--signal-soft);
}
.eyebrow::before{
  content:"";
  width:14px;
  height:2px;
  border-radius:2px;
  background:var(--signal);
}
.section-title{font-size:clamp(1.6rem,2.6vw,2.4rem)}
.lede{
  font-size:clamp(1.05rem,1.35vw,1.25rem);
  line-height:1.8;
  color:#CBD9E4;
  max-width:62ch;
}
.stack > * + *{margin-top:var(--stack-gap,1rem)}
.rule{
  height:1px;
  border:0;
  background:linear-gradient(90deg,var(--line-strong),transparent 82%);
  margin-block:clamp(20px,3vw,36px);
}
.note{
  border-left:2px solid var(--signal);
  padding:10px 0 10px 16px;
  color:var(--text-dim);
  font-size:.9rem;
  max-width:60ch;
}
.chip{
  display:inline-flex;
  align-items:center;
  gap:7px;
  padding:4px 11px;
  border-radius:var(--radius-pill);
  border:1px solid var(--line-strong);
  font-family:var(--font-mono);
  font-size:.6875rem;
  letter-spacing:.14em;
  text-transform:uppercase;
  color:var(--sage);
}
.chip--signal{
  color:var(--signal-soft);
  border-color:rgba(255,106,42,.5);
  background:rgba(255,106,42,.08);
}
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  padding:11px 18px;
  border-radius:var(--radius-pill);
  border:1px solid transparent;
  font-family:var(--font-head);
  font-weight:700;
  font-size:.9rem;
  letter-spacing:.02em;
  line-height:1.2;
  transition:background .22s var(--ease),color .22s var(--ease),
             border-color .22s var(--ease),transform .22s var(--ease);
}
.btn:active{transform:translateY(1px)}
.btn--signal{
  background:linear-gradient(135deg,#FF7B3E,var(--signal));
  color:var(--ink-950);
  box-shadow:0 10px 26px rgba(255,106,42,.3);
}
.btn--signal:hover{background:var(--signal-soft);color:var(--ink-950)}
.btn--line{
  border-color:var(--line-strong);
  color:var(--text);
  background:rgba(6,19,31,.2);
}
.btn--line:hover{border-color:var(--signal);color:var(--snow);background:rgba(255,106,42,.1)}

/* 面包屑 */
.breadcrumb{margin-block:clamp(14px,2vw,24px)}
.breadcrumb-list{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:8px;
  font-family:var(--font-mono);
  font-size:.75rem;
  letter-spacing:.08em;
  color:var(--text-dim);
}
.breadcrumb-item{display:inline-flex;align-items:center;gap:8px}
.breadcrumb-item:not(:last-child)::after{
  content:"/";
  color:rgba(159,184,168,.5);
}
.breadcrumb-link{color:var(--sage);transition:color .2s var(--ease)}
.breadcrumb-link:hover{color:var(--signal-soft)}
.breadcrumb-current{color:var(--text)}

/* 网格 */
.grid{display:grid;gap:clamp(16px,2.4vw,30px)}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid--split{grid-template-columns:minmax(0,7fr) minmax(0,4fr)}

/* 路标条目 */
.marker{
  display:flex;
  flex-wrap:wrap;
  gap:6px 16px;
  padding:16px 0;
  border-top:1px dashed var(--line-soft);
}
.marker-code{
  flex:0 0 auto;
  min-width:2.6em;
  font-family:var(--font-mono);
  font-size:.75rem;
  letter-spacing:.1em;
  color:var(--signal);
}
.marker-title{
  flex:1 1 12em;
  font-family:var(--font-head);
  font-weight:800;
  font-size:clamp(1rem,1.5vw,1.15rem);
  color:var(--snow);
}
.marker-body{
  flex:1 1 100%;
  color:var(--text-dim);
  font-size:.92rem;
  max-width:64ch;
}

/* 图片容器 */
.media{
  position:relative;
  overflow:hidden;
  border-radius:var(--radius-card);
  border:1px solid var(--line-soft);
  background:
    linear-gradient(135deg,rgba(18,59,93,.95),rgba(6,19,31,.95)),
    var(--rail-800);
}
.media::after{
  content:"";
  position:absolute;
  inset:auto 0 0 0;
  height:2px;
  background:linear-gradient(90deg,var(--signal) 0 64px,rgba(159,184,168,.35) 64px 100%);
  opacity:.75;
  pointer-events:none;
}
.media img{width:100%;height:100%;object-fit:cover}
.media--16x9{aspect-ratio:16/9}
.media--3x2{aspect-ratio:3/2}
.media--4x3{aspect-ratio:4/3}
.media-caption{
  margin-top:8px;
  font-family:var(--font-mono);
  font-size:.75rem;
  letter-spacing:.04em;
  color:var(--text-dim);
}

/* 5. 页头 */
.skip-link{
  position:absolute;
  left:50%;
  top:8px;
  transform:translate(-50%,-160%);
  z-index:120;
  padding:10px 18px;
  border-radius:var(--radius-pill);
  background:var(--signal);
  color:var(--ink-950);
  font-weight:700;
  font-size:.85rem;
  transition:transform .2s var(--ease);
}
.skip-link:focus{transform:translate(-50%,0)}

.site-header{
  position:sticky;
  top:0;
  z-index:80;
  padding:clamp(8px,1.2vw,16px) clamp(10px,2vw,26px) 0;
}
.header-capsule{
  width:100%;
  max-width:1320px;
  margin-inline:auto;
  padding:8px clamp(10px,1.6vw,18px) 9px;
  border-radius:var(--radius-cap);
  border:1px solid var(--line-soft);
  background:linear-gradient(180deg,rgba(11,30,46,.95),rgba(6,19,31,.88));
  box-shadow:var(--shadow-cap);
  -webkit-backdrop-filter:blur(18px) saturate(150%);
  backdrop-filter:blur(18px) saturate(150%);
  transition:padding .28s var(--ease),box-shadow .28s var(--ease);
}
.site-header[data-scrolled="true"] .header-capsule{
  padding-block:4px 6px;
  box-shadow:var(--shadow-float);
}
.capsule-top{
  display:flex;
  align-items:center;
  gap:clamp(10px,1.6vw,22px);
}

.brand{
  display:inline-flex;
  align-items:center;
  gap:10px;
  flex:0 0 auto;
  padding:4px 2px;
  border-radius:14px;
  color:var(--snow);
}
.brand-mark{
  display:inline-grid;
  place-items:center;
  width:34px;
  height:34px;
  border-radius:10px;
  background:linear-gradient(145deg,#FF7B3E,var(--signal-soft));
  box-shadow:0 6px 16px rgba(255,106,42,.35);
}
.brand-arrow{
  width:9px;
  height:9px;
  margin-left:-2px;
  border-top:2px solid var(--ink-950);
  border-right:2px solid var(--ink-950);
  transform:rotate(45deg);
}
.brand-text{display:flex;flex-direction:column;line-height:1.1}
.brand-name{
  font-family:var(--font-head);
  font-weight:800;
  font-size:.98rem;
  letter-spacing:.05em;
  color:var(--snow);
}
.brand-line{
  margin-top:4px;
  font-family:var(--font-mono);
  font-size:.625rem;
  letter-spacing:.1em;
  color:var(--text-dim);
}
.brand--footer{margin-bottom:18px}

.nav-toggle{
  display:none;
  align-items:center;
  gap:8px;
  margin-left:auto;
  padding:9px 14px;
  border-radius:var(--radius-pill);
  border:1px solid var(--line-strong);
  font-family:var(--font-mono);
  font-size:.72rem;
  letter-spacing:.14em;
  color:var(--text);
  transition:border-color .2s var(--ease),color .2s var(--ease);
}
.nav-toggle:hover{border-color:var(--signal);color:var(--snow)}
.nav-toggle-icon{display:inline-flex;flex-direction:column;gap:4px;width:16px}
.nav-toggle-bar{
  display:block;
  height:2px;
  border-radius:2px;
  background:var(--signal);
  transition:transform .24s var(--ease);
}
.nav-toggle-label{white-space:nowrap}

.site-nav{
  flex:1 1 auto;
  min-width:0;
  display:flex;
  flex-direction:column;
  gap:2px;
}
.nav-row{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:10px;
}
.nav-list{
  display:flex;
  align-items:center;
  gap:2px;
  overflow-x:auto;
  scrollbar-width:none;
}
.nav-list::-webkit-scrollbar{display:none}
.nav-link{
  position:relative;
  display:inline-block;
  padding:9px 12px;
  border-radius:var(--radius-pill);
  font-size:.875rem;
  color:#C6D5E1;
  white-space:nowrap;
  transition:color .2s var(--ease),background .2s var(--ease);
}
.nav-link:hover{color:var(--snow);background:rgba(159,184,168,.12)}
.nav-link[aria-current="page"]{
  color:var(--snow);
  background:rgba(255,106,42,.16);
}
.nav-link[aria-current="page"]::after{
  content:"";
  position:absolute;
  left:50%;
  bottom:3px;
  width:14px;
  height:2px;
  border-radius:2px;
  background:var(--signal);
  transform:translateX(-50%);
}
.nav-cta{flex:0 0 auto}

.tag-rail{
  display:flex;
  align-items:center;
  gap:6px;
  margin-top:6px;
  padding-top:8px;
  border-top:1px dashed var(--line-soft);
  overflow-x:auto;
  scrollbar-width:none;
}
.tag-rail::-webkit-scrollbar{display:none}
.tag-item{flex:0 0 auto}
.tag-chip{
  display:inline-flex;
  align-items:center;
  gap:7px;
  padding:5px 11px 5px 6px;
  border-radius:var(--radius-pill);
  border:1px solid rgba(159,184,168,.28);
  color:#C3D3CB;
  font-size:.6875rem;
  letter-spacing:.1em;
  white-space:nowrap;
  transition:border-color .2s var(--ease),color .2s var(--ease),background .2s var(--ease);
}
.tag-chip:hover{border-color:var(--signal);color:var(--snow);background:rgba(255,106,42,.1)}
.tag-chip[aria-current="page"]{border-color:var(--signal);color:var(--snow)}
.tag-code{
  display:inline-grid;
  place-items:center;
  min-width:18px;
  height:18px;
  padding:0 4px;
  border-radius:6px;
  background:rgba(159,184,168,.16);
  color:var(--sage);
  font-family:var(--font-mono);
  font-size:.625rem;
  letter-spacing:.04em;
}
.tag-chip[aria-current="page"] .tag-code{background:var(--signal);color:var(--ink-950)}
.tag-name{letter-spacing:.08em}

/* 6. 页脚 */
.site-footer{
  position:relative;
  margin-top:clamp(56px,9vw,112px);
  padding-top:clamp(32px,5vw,60px);
  overflow:hidden;
  color:var(--text);
  background:radial-gradient(120% 130% at 100% 0%,#0B1E2E 0%,#06131F 62%);
  border-top:1px solid var(--line-soft);
}
.site-footer::before{
  content:"";
  position:absolute;
  inset:0 0 auto 0;
  height:3px;
  background:linear-gradient(90deg,var(--signal) 0 96px,rgba(159,184,168,.22) 96px 100%);
}
.site-footer::after{
  content:"";
  position:absolute;
  left:0;
  right:0;
  top:22px;
  height:1px;
  background:repeating-linear-gradient(90deg,rgba(159,184,168,.3) 0 22px,transparent 22px 46px);
  opacity:.55;
  pointer-events:none;
}
.footer-inner{
  display:grid;
  grid-template-columns:minmax(0,1fr) minmax(0,1.7fr);
  gap:clamp(26px,4vw,56px);
  padding-bottom:clamp(26px,4vw,48px);
}
.footer-lead{max-width:38ch}
.footer-summary{
  margin-top:14px;
  font-size:.95rem;
  color:var(--text-dim);
  max-width:36ch;
}
.footer-action{margin-top:20px}
.footer-nav{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  gap:clamp(18px,3vw,36px);
}
.footer-title{
  display:flex;
  align-items:center;
  gap:8px;
  margin-bottom:14px;
  font-family:var(--font-mono);
  font-size:.6875rem;
  font-weight:600;
  letter-spacing:.18em;
  text-transform:uppercase;
  color:var(--sage);
}
.footer-title::before{
  content:"";
  width:14px;
  height:2px;
  border-radius:2px;
  background:var(--signal);
}
.footer-list{display:flex;flex-direction:column;gap:2px}
.footer-link{
  display:inline-block;
  padding:5px 0;
  font-size:.9rem;
  color:#C6D5E1;
  border-bottom:1px solid transparent;
  transition:color .2s var(--ease),border-color .2s var(--ease);
}
.footer-link:hover{color:var(--snow);border-bottom-color:rgba(255,106,42,.6)}
.footer-link[aria-current="page"]{color:var(--signal-soft)}
.footer-key{
  display:block;
  margin-top:8px;
  font-family:var(--font-mono);
  font-size:.625rem;
  letter-spacing:.14em;
  text-transform:uppercase;
  color:rgba(159,184,168,.85);
}
.footer-value{
  display:block;
  font-family:var(--font-mono);
  font-size:.8125rem;
  line-height:1.6;
  color:var(--text);
  overflow-wrap:anywhere;
}
.footer-col--contact .footer-list > li + li{margin-top:4px}
.footer-base{
  display:flex;
  flex-wrap:wrap;
  justify-content:space-between;
  gap:8px 24px;
  padding-block:16px 28px;
  border-top:1px solid var(--line-soft);
}
.footer-fine{
  font-family:var(--font-mono);
  font-size:.75rem;
  letter-spacing:.03em;
  color:var(--text-dim);
  max-width:none;
}

/* 返回顶部与滚动进度 */
.to-top{
  position:fixed;
  right:clamp(14px,2.5vw,28px);
  bottom:clamp(14px,2.5vw,28px);
  z-index:85;
  padding:10px 16px;
  border-radius:var(--radius-pill);
  border:1px solid rgba(255,106,42,.55);
  background:rgba(11,30,46,.92);
  color:var(--text);
  font-family:var(--font-mono);
  font-size:.72rem;
  letter-spacing:.12em;
  box-shadow:var(--shadow-float);
  -webkit-backdrop-filter:blur(12px);
  backdrop-filter:blur(12px);
  opacity:0;
  transform:translateY(10px);
  pointer-events:none;
  transition:opacity .24s var(--ease),transform .24s var(--ease),border-color .24s var(--ease);
}
.to-top:hover{border-color:var(--signal);color:var(--snow)}
.to-top[data-visible="true"]{
  opacity:1;
  transform:none;
  pointer-events:auto;
}
.scroll-progress{
  position:fixed;
  inset:0 0 auto 0;
  height:3px;
  z-index:90;
  background:rgba(159,184,168,.1);
  pointer-events:none;
}
.scroll-progress-bar{
  display:block;
  height:100%;
  width:100%;
  transform:scaleX(0);
  transform-origin:0 50%;
  background:linear-gradient(90deg,var(--signal),var(--signal-soft));
}

/* 7. 响应式 */
@media (max-width:1024px){
  .grid--3{grid-template-columns:repeat(2,minmax(0,1fr))}
  .grid--split{grid-template-columns:1fr}
  .footer-inner{grid-template-columns:1fr}
  .footer-lead{max-width:none}
}
@media (max-width:920px){
  [id]{scroll-margin-top:96px}
  .site-header{padding:8px 10px 0}
  .header-capsule{border-radius:20px;padding:8px 12px 10px}
  .capsule-top{flex-wrap:wrap;row-gap:8px}
  .nav-toggle{display:inline-flex}
  .site-nav{
    display:none;
    order:3;
    width:100%;
    padding-top:10px;
    margin-top:2px;
    border-top:1px solid var(--line-soft);
  }
  .site-header[data-open="true"] .site-nav{
    display:flex;
    animation:nav-drop .26s var(--ease) both;
  }
  .site-header[data-open="true"] .nav-toggle{border-color:var(--signal);color:var(--snow)}
  .site-header[data-open="true"] .nav-toggle-bar:first-child{transform:translateY(3px) rotate(45deg)}
  .site-header[data-open="true"] .nav-toggle-bar:last-child{transform:translateY(-3px) rotate(-45deg)}
  .nav-row{flex-direction:column;align-items:stretch;gap:8px}
  .nav-list{flex-direction:column;align-items:stretch;gap:2px;overflow:visible}
  .nav-link{display:block;padding:12px;border-radius:12px;font-size:.95rem}
  .nav-link[aria-current="page"]::after{left:12px;bottom:8px;transform:none}
  .nav-cta{width:100%;margin-top:4px}
  .tag-rail{
    display:grid;
    grid-template-columns:repeat(2,minmax(0,1fr));
    gap:8px;
    overflow:visible;
    margin-top:8px;
  }
  .tag-chip{justify-content:flex-start}
  .footer-nav{grid-template-columns:repeat(2,minmax(0,1fr))}
  .grid--2,.grid--3{grid-template-columns:1fr}
}
@media (max-width:640px){
  .footer-nav{grid-template-columns:1fr}
  .footer-base{flex-direction:column;align-items:flex-start}
  .to-top{font-size:.6875rem;padding:9px 13px}
  .brand-line{display:none}
}
@keyframes nav-drop{
  from{opacity:0;transform:translateY(-6px)}
  to{opacity:1;transform:none}
}

/* 8. 可访问性与动效偏好 */
:focus-visible{
  outline:2px solid var(--signal);
  outline-offset:3px;
  border-radius:6px;
}
.has-js [data-reveal]{
  opacity:0;
  transform:translateY(14px);
  transition:opacity .4s var(--ease),transform .4s var(--ease);
}
.has-js [data-reveal].is-revealed{
  opacity:1;
  transform:none;
}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  .has-js [data-reveal]{opacity:1;transform:none}
  .to-top{transition:none}
}