/* =========================================================
   site.css — 贝斯特2255 共享外壳
   1 Reset / 2 Tokens / 3 Base / 4 Layout / 5 Buttons
   6 Header / 7 Footer / 8 Shared components / 9 Motion
   ========================================================= */

/* ---------- 1. Reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;text-size-adjust:100%}
body,h1,h2,h3,h4,h5,h6,p,figure,blockquote,dl,dd,ul,ol{margin:0}
ul,ol{padding:0;list-style:none}
img,svg,video{display:block;max-width:100%}
button{font:inherit;color:inherit;background:none;border:0;padding:0}
a{color:inherit;text-decoration:none}
table{border-collapse:collapse;width:100%}
:where(input,textarea,select){font:inherit}

/* ---------- 2. Tokens ---------- */
:root{
  --navy:#0B1F33;
  --navy-2:#12314D;
  --copper:#C75B12;
  --copper-deep:#9E430B;
  --cyan:#1AAE9F;
  --teal:#2F8F83;
  --moon:#F7F3E8;
  --sand:#DAD2C3;
  --warm:#FFFDF7;
  --ink:#1C1C1C;
  --violet:#6C5B8E;

  --font-sans:"Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-mono:"JetBrains Mono","IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,"Courier New",monospace;

  --shell:1360px;
  --gutter:clamp(18px,4vw,60px);
  --header-meta-h:36px;
  --header-main-h:80px;
  --header-h:calc(var(--header-meta-h) + var(--header-main-h));
  --ease:cubic-bezier(.22,.61,.36,1);
  --hair:rgba(11,31,51,.16);
  --hair-light:rgba(247,243,232,.16);
}
@media (max-width:1024px){
  :root{--header-meta-h:30px;--header-main-h:64px}
}

/* ---------- 3. Base ---------- */
html{scroll-padding-top:calc(var(--header-h) + 16px)}
body{
  min-height:100vh;
  background:var(--moon);
  color:var(--ink);
  font-family:var(--font-sans);
  font-size:16px;
  line-height:1.75;
  letter-spacing:.01em;
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
}
h1,h2,h3,h4{font-weight:900;line-height:1.16;letter-spacing:-.03em;color:var(--navy)}
:focus-visible{outline:3px solid var(--cyan);outline-offset:3px}
::selection{background:var(--navy);color:var(--moon)}

#main-content{display:block;scroll-margin-top:calc(var(--header-h) + 16px)}

.mono{font-family:var(--font-mono);font-variant-numeric:tabular-nums;letter-spacing:.06em}
.visually-hidden{position:absolute!important;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);clip-path:inset(50%);white-space:nowrap;border:0}

.skip-link{
  position:fixed;top:0;left:0;z-index:300;
  transform:translateY(-150%);
  padding:12px 22px;
  background:var(--copper-deep);
  color:var(--warm);
  font-size:14px;font-weight:700;letter-spacing:.08em;
  transition:transform .18s var(--ease);
}
.skip-link:focus{transform:translateY(0)}

/* ---------- 4. Layout ---------- */
.shell{
  width:100%;
  max-width:var(--shell);
  margin-inline:auto;
  padding-inline:var(--gutter);
}
.grid12{
  display:grid;
  grid-template-columns:repeat(12,minmax(0,1fr));
  gap:clamp(16px,2.2vw,32px);
}
.prose{
  max-width:36em;
  font-size:clamp(16px,1.05vw,17.5px);
  line-height:1.8;
  color:var(--ink);
}
.prose p + p{margin-top:1.1em}
.prose h3{font-size:1.25rem;margin-top:1.9em;margin-bottom:.6em}
.prose ul{display:grid;gap:.55em}
.prose ul li{position:relative;padding-left:1.35em}
.prose ul li::before{content:"";position:absolute;left:0;top:.78em;width:9px;height:2px;background:var(--copper)}
.prose a{color:var(--copper-deep);text-decoration:underline;text-underline-offset:3px}

/* ---------- 5. Buttons ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:.6em;
  padding:12px 22px;
  border:1px solid transparent;
  border-radius:0;
  font-size:14px;font-weight:700;line-height:1.2;letter-spacing:.06em;
  text-align:center;cursor:pointer;
  transition:background-color .2s var(--ease),color .2s var(--ease),border-color .2s var(--ease),transform .2s var(--ease);
}
.btn--copper{background:var(--copper-deep);border-color:var(--copper-deep);color:var(--warm)}
.btn--copper:hover{background:var(--copper);border-color:var(--copper);color:#fff}
.btn--ghost{background:transparent;border-color:rgba(11,31,51,.4);color:var(--navy)}
.btn--ghost:hover{background:var(--navy);border-color:var(--navy);color:var(--warm)}
.btn--light{background:var(--warm);border-color:var(--moon);color:var(--navy)}
.btn--light:hover{background:var(--cyan);border-color:var(--cyan);color:#052521}
.btn--block{width:100%}
.btn:hover{transform:translateY(-1px)}

/* ---------- 6. Header ---------- */
.site-header{
  position:sticky;top:0;z-index:100;
  background:var(--navy);
  color:var(--moon);
  isolation:isolate;
}
.header-meta{background:var(--navy-2);border-bottom:1px solid var(--hair-light)}
.header-meta__inner{
  display:flex;align-items:center;
  gap:clamp(14px,2vw,28px);
  min-height:var(--header-meta-h);
  font-family:var(--font-mono);
  font-size:11px;letter-spacing:.2em;
  color:rgba(247,243,232,.72);
}
.header-meta__batch{white-space:nowrap;color:rgba(247,243,232,.8)}
.header-meta__ticks{
  flex:1 1 auto;min-width:24px;height:9px;
  background-image:repeating-linear-gradient(90deg,rgba(247,243,232,.34) 0 1px,transparent 1px 9px);
  opacity:.7;
}
.header-meta__link{
  white-space:nowrap;
  color:var(--warm);
  border-bottom:1px solid rgba(26,174,159,.6);
  padding-bottom:1px;
  transition:color .2s var(--ease),border-color .2s var(--ease);
}
.header-meta__link:hover{color:var(--cyan);border-color:var(--cyan)}

.header-main{position:relative;background:var(--navy)}
.header-main__inner{
  display:flex;align-items:center;justify-content:space-between;
  gap:clamp(16px,3vw,40px);
  min-height:var(--header-main-h);
  padding-block:10px;
}

.brand{
  display:flex;flex-direction:column;gap:7px;
  flex:0 0 auto;
  padding-left:14px;
  border-left:3px solid var(--copper);
}
.brand__name{
  display:flex;align-items:baseline;gap:.28em;
  font-size:clamp(19px,1.7vw,24px);
  font-weight:900;letter-spacing:-.03em;line-height:1;
  color:var(--warm);
}
.brand__num{font-size:.62em;font-weight:700;letter-spacing:.04em;color:var(--cyan)}
.brand__line{
  font-family:var(--font-mono);
  font-size:10.5px;letter-spacing:.28em;line-height:1;
  color:rgba(247,243,232,.58);
}

.nav{
  display:flex;align-items:center;
  gap:clamp(14px,2.4vw,32px);
  margin-left:auto;
}
.nav::before{
  content:"";flex:0 0 1px;
  align-self:stretch;max-height:34px;margin-block:auto;
  background:rgba(247,243,232,.2);
}
.nav__list{display:flex;align-items:center;gap:clamp(10px,1.7vw,26px)}
.nav__item{display:flex}
.nav__link{
  position:relative;
  display:inline-flex;align-items:baseline;gap:.42em;
  padding:10px 0;
  font-size:14px;letter-spacing:.04em;
  color:rgba(247,243,232,.8);
  transition:color .2s var(--ease);
}
.nav__idx{
  font-family:var(--font-mono);
  font-size:10.5px;letter-spacing:.06em;
  color:var(--cyan);opacity:.78;
}
.nav__link::after{
  content:"";position:absolute;left:0;right:0;bottom:1px;height:2px;
  background:var(--cyan);
  transform:scaleX(0);transform-origin:left center;
  transition:transform .26s var(--ease);
}
.nav__link:hover{color:var(--warm)}
.nav__link:hover::after{transform:scaleX(1)}
.nav__link[aria-current="page"]{color:var(--warm);font-weight:700}
.nav__link[aria-current="page"]::after{transform:scaleX(1);background:var(--copper)}
.nav__link[aria-current="page"] .nav__idx{color:var(--copper);opacity:1}
.nav__cta{flex:0 0 auto;padding:11px 18px}

.nav-toggle{
  display:none;
  align-items:center;gap:10px;
  padding:9px 14px;
  border:1px solid rgba(247,243,232,.3);
  color:var(--warm);
  font-family:var(--font-mono);
  font-size:12px;letter-spacing:.2em;
  cursor:pointer;z-index:120;
  transition:border-color .2s var(--ease),color .2s var(--ease);
}
.nav-toggle:hover{border-color:var(--cyan);color:var(--cyan)}
.nav-toggle__label{line-height:1}
.nav-toggle__bars{display:inline-flex;flex-direction:column;gap:4px;width:16px}
.nav-toggle__bars span{
  display:block;height:2px;width:100%;background:currentColor;
  transition:transform .22s var(--ease),opacity .22s var(--ease);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:first-child{transform:translateY(3px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:last-child{transform:translateY(-3px) rotate(-45deg)}

.scroll-progress{
  position:absolute;left:0;right:0;bottom:0;height:3px;
  background:rgba(247,243,232,.1);
  overflow:hidden;
}
.scroll-progress span{
  display:block;width:100%;height:100%;
  transform:scaleX(0);transform-origin:left center;
  background:linear-gradient(90deg,var(--cyan) 0%,var(--teal) 56%,var(--copper) 100%);
}

html.is-nav-open body{overflow:hidden}

/* ---------- 7. Footer ---------- */
.site-footer{
  margin-top:clamp(48px,8vw,96px);
  background:var(--navy);
  color:rgba(247,243,232,.76);
  border-top:4px solid var(--copper);
}
.footer-top{
  display:grid;
  grid-template-columns:minmax(0,1.15fr) minmax(0,1.85fr);
  gap:clamp(32px,5vw,80px);
  padding-block:clamp(40px,6vw,76px);
}
.footer-brand{display:flex;flex-direction:column;align-items:flex-start}
.footer-kicker{
  font-family:var(--font-mono);
  font-size:11px;letter-spacing:.26em;
  color:var(--cyan);
  margin-bottom:16px;
}
.footer-brand__name{
  font-size:clamp(24px,3vw,34px);
  font-weight:900;letter-spacing:-.03em;line-height:1.1;
  color:var(--warm);
  border-bottom:2px solid transparent;
  transition:color .2s var(--ease),border-color .2s var(--ease);
}
.footer-brand__name:hover{color:var(--cyan);border-bottom-color:var(--cyan)}
.footer-brand__note{
  max-width:26em;margin-top:14px;
  font-size:14.5px;line-height:1.8;
  color:rgba(247,243,232,.66);
}
.footer-contact{display:grid;gap:9px;margin-top:26px;width:100%;max-width:32em}
.footer-contact li{
  display:grid;grid-template-columns:3.4em minmax(0,1fr);
  gap:12px;
  font-family:var(--font-mono);
  font-size:12.5px;line-height:1.6;
  color:rgba(247,243,232,.82);
  overflow-wrap:anywhere;
}
.footer-contact__k{color:var(--cyan);letter-spacing:.12em}

.footer-cols{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  gap:clamp(20px,3vw,44px);
  align-content:start;
}
.footer-col{display:grid;align-content:start}
.footer-col__head{
  font-family:var(--font-mono);
  font-size:11px;font-weight:500;letter-spacing:.26em;
  color:var(--cyan);
  padding-bottom:12px;
  border-bottom:1px solid var(--hair-light);
  margin-bottom:16px;
}
.footer-col__list{display:grid;gap:12px}
.footer-col__link{
  font-size:14.5px;
  color:rgba(247,243,232,.8);
  transition:color .2s var(--ease);
}
.footer-col__link:hover{
  color:var(--warm);
  text-decoration:underline;
  text-underline-offset:4px;
  text-decoration-color:var(--copper);
}

.footer-bottom{background:var(--navy-2);border-top:1px solid var(--hair-light)}
.footer-bottom__inner{
  display:flex;flex-wrap:wrap;align-items:center;
  gap:10px clamp(16px,3vw,40px);
  padding-block:16px;
  font-size:11.5px;letter-spacing:.1em;
}
.footer-copy{font-family:var(--font-mono);color:rgba(247,243,232,.74)}
.footer-icp{font-family:var(--font-mono);color:rgba(247,243,232,.6)}
.footer-note{color:rgba(247,243,232,.56);margin-left:auto;letter-spacing:.04em}

/* ---------- 8. Shared components ---------- */
.breadcrumb{
  display:flex;flex-wrap:wrap;align-items:center;
  gap:.5em;
  margin-bottom:clamp(18px,3vw,32px);
  font-family:var(--font-mono);
  font-size:11.5px;letter-spacing:.14em;
  color:rgba(11,31,51,.55);
}
.breadcrumb li{display:inline-flex;align-items:center;gap:.5em}
.breadcrumb__link{color:var(--navy);border-bottom:1px solid rgba(11,31,51,.25);padding-bottom:1px}
.breadcrumb__link:hover{color:var(--copper-deep);border-bottom-color:var(--copper-deep)}
.breadcrumb__sep{color:var(--copper)}
.breadcrumb__current{color:rgba(11,31,51,.62)}

.eyebrow{
  display:inline-flex;align-items:center;gap:.7em;
  font-family:var(--font-mono);
  font-size:11.5px;letter-spacing:.24em;text-transform:uppercase;
  color:var(--teal);
}
.eyebrow::before{content:"";width:18px;height:2px;background:currentColor}
.section-head{display:grid;gap:10px;margin-bottom:clamp(20px,3vw,36px)}
.section-title{font-size:clamp(26px,3.4vw,44px);line-height:1.06;letter-spacing:-.04em}
.section-num{font-family:var(--font-mono);font-size:12px;letter-spacing:.2em;color:var(--copper)}
.rule{width:100%;height:1px;border:0;background:var(--hair)}
.rule--dark{background:var(--hair-light)}

.tag{
  display:inline-flex;align-items:center;gap:.45em;
  padding:4px 9px;
  font-family:var(--font-mono);
  font-size:11px;letter-spacing:.1em;
  background:var(--sand);color:var(--navy);
  border:1px solid rgba(11,31,51,.12);
}
.tag--cyan{background:rgba(26,174,159,.16);color:#10655c;border-color:rgba(26,174,159,.42)}
.tag--violet{background:rgba(108,91,142,.16);color:#4a3e66;border-color:rgba(108,91,142,.4)}
.tag--copper{background:rgba(199,91,18,.16);color:var(--copper-deep);border-color:rgba(199,91,18,.4)}

.panel{
  position:relative;
  padding:clamp(18px,2.4vw,28px);
  background:var(--warm);
  border:1px solid var(--sand);
}
.panel--edge{border-top:3px solid var(--copper)}
.panel__meta{
  font-family:var(--font-mono);
  font-size:11.5px;letter-spacing:.12em;
  color:var(--teal);
  margin-bottom:10px;
}

.index-list{display:grid;border-top:1px solid var(--hair)}
.index-list__item{
  display:grid;
  grid-template-columns:3.6em minmax(0,1fr) auto;
  gap:clamp(12px,2vw,28px);
  align-items:baseline;
  padding:18px 0;
  border-bottom:1px solid var(--hair);
}
.index-list__num{font-family:var(--font-mono);font-size:12px;letter-spacing:.1em;color:var(--copper)}
.index-list__title{font-size:clamp(17px,1.7vw,21px);font-weight:700;letter-spacing:-.02em;color:var(--navy)}
.index-list__meta{font-family:var(--font-mono);font-size:11.5px;letter-spacing:.1em;color:rgba(11,31,51,.55)}

.filter-bar{
  display:flex;flex-wrap:wrap;gap:8px;
  padding:14px 0;
  border-top:1px solid var(--hair);
  border-bottom:1px solid var(--hair);
}
.filter-chip{
  display:inline-flex;align-items:center;gap:.5em;
  padding:8px 14px;
  border:1px solid rgba(11,31,51,.28);
  background:transparent;
  font-family:var(--font-mono);
  font-size:12px;letter-spacing:.08em;
  color:var(--navy);cursor:pointer;
  transition:background-color .2s var(--ease),color .2s var(--ease),border-color .2s var(--ease);
}
.filter-chip:hover{border-color:var(--navy);background:rgba(11,31,51,.05)}
.filter-chip[aria-pressed="true"]{background:var(--navy);border-color:var(--navy);color:var(--warm)}
.filter-chip__count{font-size:10.5px;color:var(--teal)}
.filter-chip[aria-pressed="true"] .filter-chip__count{color:var(--cyan)}

.notes-rail{
  writing-mode:vertical-rl;
  text-orientation:mixed;
  font-family:var(--font-mono);
  font-size:11px;letter-spacing:.32em;
  color:rgba(11,31,51,.45);
  padding-block:14px;
}
.notes-rail--copper{color:var(--copper)}

.media-frame{
  position:relative;
  overflow:hidden;
  aspect-ratio:16/10;
  border:1px solid var(--hair);
  background:
    repeating-linear-gradient(135deg,rgba(11,31,51,.06) 0 1px,transparent 1px 9px),
    linear-gradient(180deg,var(--sand),#cdc4b3);
}
.media-frame > img,
.media-frame > picture > img{width:100%;height:100%;object-fit:cover}
.media-frame--wide{aspect-ratio:21/9}
.media-frame--tall{aspect-ratio:3/4}
.media-frame--square{aspect-ratio:1/1}
.media-frame__caption{
  position:absolute;left:0;bottom:0;max-width:100%;
  padding:8px 12px;
  background:rgba(11,31,51,.88);
  color:var(--moon);
  font-family:var(--font-mono);
  font-size:11px;letter-spacing:.12em;
}

/* ---------- 9. Motion & responsive ---------- */
.js [data-reveal]{
  opacity:0;
  transform:translateY(16px);
  transition:opacity .6s var(--ease),transform .6s var(--ease);
}
.js [data-reveal].is-visible{opacity:1;transform:none}

@media (max-width:1024px){
  .header-meta__ticks{display:none}
  .header-meta__inner{justify-content:space-between;gap:12px;font-size:10px;letter-spacing:.14em}
  .header-meta__link{font-size:10px}

  .nav-toggle{display:inline-flex}

  .nav{
    position:fixed;
    top:var(--header-h);left:0;right:0;bottom:0;
    z-index:110;
    display:flex;flex-direction:column;align-items:stretch;
    gap:0;margin-left:0;
    padding:clamp(24px,5vw,44px) var(--gutter) 40px;
    background:var(--navy);
    border-top:1px solid var(--hair-light);
    overflow-y:auto;
    opacity:0;visibility:hidden;pointer-events:none;
    transform:translateY(-10px);
    transition:opacity .26s var(--ease),transform .26s var(--ease),visibility .26s;
  }
  .nav::before{display:none}
  .nav[data-open="true"]{opacity:1;visibility:visible;pointer-events:auto;transform:none}

  .nav__list{flex-direction:column;align-items:stretch;gap:0;width:100%}
  .nav__item{display:block;border-bottom:1px solid var(--hair-light)}
  .nav__link{
    width:100%;
    padding:16px 0;
    font-size:clamp(20px,5.5vw,26px);
    font-weight:900;letter-spacing:-.02em;
    color:var(--moon);
  }
  .nav__idx{flex:0 0 auto;width:2.6em;font-size:11px}
  .nav__link::after{display:none}
  .nav__link[aria-current="page"]{color:var(--cyan)}
  .nav__link[aria-current="page"] .nav__idx{color:var(--cyan)}
  .nav__cta{margin-top:clamp(20px,4vw,32px);width:100%;padding:16px}
}

@media (max-width:900px){
  .footer-top{grid-template-columns:1fr}
  .footer-cols{grid-template-columns:repeat(2,minmax(0,1fr));row-gap:32px}
}

@media (max-width:640px){
  .index-list__item{grid-template-columns:2.8em minmax(0,1fr)}
  .index-list__meta{grid-column:2;margin-top:6px}
}

@media (max-width:560px){
  .footer-cols{grid-template-columns:1fr;gap:28px}
  .footer-note{margin-left:0;width:100%}
  .footer-bottom__inner{font-size:11px;letter-spacing:.06em}
  .brand{padding-left:11px}
}

@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{
    animation-duration:.01ms!important;
    animation-iteration-count:1!important;
    transition-duration:.01ms!important;
    scroll-behavior:auto!important;
  }
  .btn:hover{transform:none}
  .js [data-reveal]{opacity:1;transform:none}
  .scroll-progress span{transition:none}
}