/* ============================================================
   K1 内容站 · 共享样式表  /assets/site.css
   Reset → 变量 → 中文排版 → 通用组件 → 头部 → 页脚 → 响应式
   ============================================================ */

/* ---------- 1. Reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body,h1,h2,h3,h4,h5,p,ul,ol,li,dl,dt,dd,figure,blockquote{margin:0;padding:0}
ul,ol{list-style:none}
img,svg,video{display:block;max-width:100%}
button,input,select,textarea{font:inherit;color:inherit}
a{color:inherit;text-decoration:none}
button{background:none;border:0;cursor:pointer}
summary{cursor:pointer}
summary::-webkit-details-marker{display:none}

/* ---------- 2. 变量 ---------- */
:root{
  --ink-bg:#0A1F1A;
  --ink-dark:#101312;
  --panel:#12302A;
  --panel-hi:#14352E;
  --cyan:#23E0C8;
  --cyan-mid:#178C7E;
  --cyan-deep:#0E5A52;
  --yellow:#E9FF57;
  --red:#E2402F;
  --white:#F4F2EA;
  --mist:#9DB4AE;
  --line:rgba(157,180,174,.16);
  --line-strong:rgba(35,224,200,.28);
  --radius-s:8px;
  --radius-m:14px;
  --radius-l:22px;
  --fs-48:clamp(2rem,1.45rem + 2.4vw,3rem);
  --fs-34:clamp(1.6rem,1.25rem + 1.5vw,2.125rem);
  --fs-24:1.5rem;
  --fs-20:1.25rem;
  --fs-16:1rem;
  --fs-14:.875rem;
  --fs-12:.75rem;
  --font-mono:ui-monospace,SFMono-Regular,Menlo,Consolas,"Liberation Mono",monospace;
  --font-sans:"Noto Sans SC","Source Han Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,sans-serif;
  --header-h:97px;
  --shell-max:1240px;
  --pad:clamp(16px,4vw,40px);
}

/* ---------- 3. 中文排版与页面底色 ---------- */
body{
  background-color:var(--ink-bg);
  background-image:
    linear-gradient(rgba(157,180,174,.045) 1px,transparent 1px),
    linear-gradient(90deg,rgba(157,180,174,.045) 1px,transparent 1px);
  background-size:64px 64px,64px 64px;
  background-attachment:fixed;
  color:var(--white);
  font-family:var(--font-sans);
  font-size:17px;
  font-weight:400;
  line-height:1.75;
  min-height:100vh;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
h1,h2,h3,h4{font-weight:700;letter-spacing:-.02em;line-height:1.25}
h1{font-size:var(--fs-48)}
h2{font-size:var(--fs-34)}
h3{font-size:var(--fs-24)}
h4{font-size:var(--fs-20)}
p{color:rgba(244,242,234,.86)}
a{transition:color .16s ease,background-color .16s ease,border-color .16s ease}
:focus-visible{outline:2px solid var(--yellow);outline-offset:2px;border-radius:4px}
::selection{background:var(--yellow);color:var(--ink-dark)}

/* ---------- 4. 通用布局 ---------- */
.shell{width:100%;max-width:var(--shell-max);margin-inline:auto;padding-inline:var(--pad)}
.prose{max-width:36em}
.prose p+p{margin-top:1em}
.prose strong{color:var(--white);font-weight:700}
.mono{font-family:var(--font-mono);letter-spacing:.04em;font-variant-numeric:tabular-nums}
.eyebrow{display:inline-flex;align-items:center;gap:8px;font-family:var(--font-mono);font-size:var(--fs-12);letter-spacing:.1em;color:var(--cyan)}
.eyebrow::before{content:"";width:18px;height:1px;background:currentColor;opacity:.75}

.band{padding-block:clamp(40px,6vw,80px)}
.band--dark{background:var(--ink-dark)}
.band--panel{background:rgba(18,48,42,.5)}

.divider-slant{height:56px;background:var(--ink-dark);clip-path:polygon(0 46%,100% 0,100% 54%,0 100%)}
.divider-slant--reverse{clip-path:polygon(0 0,100% 46%,100% 100%,0 54%)}

.section-head{display:grid;gap:10px;margin-bottom:clamp(20px,3vw,34px);max-width:44em}
.section-head__index{font-family:var(--font-mono);font-size:var(--fs-12);letter-spacing:.08em;color:var(--cyan)}
.section-head__title{font-size:var(--fs-34);font-weight:700;letter-spacing:-.02em}
.section-head__note{font-size:var(--fs-14);color:var(--mist);max-width:34em}

/* ---------- 5. 通用组件 ---------- */
.btn{display:inline-flex;align-items:center;gap:8px;font-family:var(--font-mono);font-size:var(--fs-14);letter-spacing:.04em;
  padding:10px 16px;border-radius:999px;border:1px solid transparent;white-space:nowrap;
  transition:transform .16s ease,background-color .16s ease,color .16s ease,border-color .16s ease,box-shadow .16s ease,filter .16s ease}
.btn--primary{background:var(--yellow);color:var(--ink-dark);border-color:var(--yellow);font-weight:700}
.btn--primary:hover{transform:translateY(-2px);filter:brightness(1.06);box-shadow:0 8px 20px rgba(233,255,87,.16)}
.btn--ghost{border-color:var(--line-strong);color:var(--cyan);background:rgba(14,90,82,.2)}
.btn--ghost:hover{background:rgba(14,90,82,.46);color:var(--white);transform:translateY(-1px)}
.btn--quiet{color:var(--mist);padding-inline:6px}
.btn--quiet:hover{color:var(--cyan)}

.chip{display:inline-flex;align-items:center;gap:6px;font-family:var(--font-mono);font-size:var(--fs-12);letter-spacing:.04em;
  padding:4px 10px;border-radius:999px;border:1px solid var(--line);color:var(--mist)}
.chip--current{background:var(--yellow);border-color:var(--yellow);color:var(--ink-dark);font-weight:700}
.chip--alert{border-color:rgba(226,64,47,.6);color:#F0806F}

.breadcrumb{font-family:var(--font-mono);font-size:var(--fs-12);letter-spacing:.04em;color:var(--mist)}
.breadcrumb ol{display:flex;flex-wrap:wrap;align-items:center;gap:0 8px}
.breadcrumb a{color:var(--mist)}
.breadcrumb a:hover{color:var(--cyan)}
.breadcrumb li+li::before{content:"/";margin-right:8px;color:rgba(157,180,174,.5)}
.breadcrumb [aria-current="page"]{color:var(--white)}

.grid{display:grid;grid-template-columns:repeat(12,minmax(0,1fr));gap:clamp(14px,2vw,28px)}
.grid>*{grid-column:span 12}
@media (min-width:768px){
  .span-3{grid-column:span 3}
  .span-4{grid-column:span 4}
  .span-5{grid-column:span 5}
  .span-6{grid-column:span 6}
  .span-7{grid-column:span 7}
  .span-8{grid-column:span 8}
  .span-9{grid-column:span 9}
  .span-12{grid-column:span 12}
}

.card{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius-m);
  padding:clamp(16px,2.2vw,24px);transition:transform .16s ease,background-color .16s ease,box-shadow .16s ease}
.card:hover{transform:translateY(-2px);background:var(--panel-hi);box-shadow:0 14px 30px rgba(0,0,0,.35)}
.card--panel{background:rgba(18,48,42,.55)}
.card__title{font-size:var(--fs-20);font-weight:700;letter-spacing:-.02em;margin-bottom:8px}
.card__meta{font-family:var(--font-mono);font-size:var(--fs-12);letter-spacing:.04em;color:var(--mist);margin-bottom:12px}
.card__body{font-size:15px;color:rgba(244,242,234,.82)}

.index-list{border-top:1px solid var(--line)}
.index-item{display:grid;grid-template-columns:64px minmax(0,1fr) auto;gap:16px;align-items:baseline;
  padding:14px 4px;border-bottom:1px solid var(--line);transition:background-color .16s ease,padding-left .16s ease}
a.index-item:hover{background:rgba(14,90,82,.28);padding-left:14px}
.index-item__num{font-family:var(--font-mono);font-size:var(--fs-12);letter-spacing:.04em;color:var(--cyan)}
.index-item__body{font-size:15.5px;color:var(--white)}
.index-item__meta{font-family:var(--font-mono);font-size:var(--fs-12);letter-spacing:.04em;color:var(--mist)}

.board{background:var(--ink-dark);border:1px solid var(--line-strong);border-radius:var(--radius-m);padding:clamp(18px,2.4vw,28px)}
.board__title{font-family:var(--font-mono);font-size:var(--fs-12);letter-spacing:.1em;color:var(--yellow);margin-bottom:16px}
.board__row{display:grid;grid-template-columns:120px minmax(0,1fr);gap:16px;padding:10px 0;border-bottom:1px dashed var(--line)}
.board__term{font-family:var(--font-mono);font-size:var(--fs-12);letter-spacing:.04em;color:var(--mist)}
.board__desc{font-size:14.5px;color:rgba(244,242,234,.86)}

.stat{display:grid;gap:6px}
.stat__num{font-family:var(--font-mono);font-variant-numeric:tabular-nums;letter-spacing:-.02em;line-height:1;
  font-size:clamp(2.5rem,1.6rem + 3.2vw,4rem);color:var(--cyan)}
.stat__unit{font-size:.34em;color:var(--mist);margin-left:6px;letter-spacing:.06em}
.stat__label{font-family:var(--font-mono);font-size:var(--fs-12);letter-spacing:.08em;color:var(--mist)}
.stat--hot .stat__num{color:var(--yellow)}

.media{position:relative;overflow:hidden;border-radius:var(--radius-l);background:var(--panel);border:1px solid var(--line)}
.media img{width:100%;height:100%;object-fit:cover}
.media--16x9{aspect-ratio:16/9}
.media--4x3{aspect-ratio:4/3}
.media--3x2{aspect-ratio:3/2}
.media--1x1{aspect-ratio:1/1}
.media--3x4{aspect-ratio:3/4}
.media--diagonal{clip-path:polygon(0 6%,100% 0,100% 94%,0 100%);border-radius:0}
.media__cap{margin-top:10px;font-family:var(--font-mono);font-size:var(--fs-12);letter-spacing:.04em;color:var(--mist)}

/* ---------- 6. 头部 ---------- */
.skip-link{position:absolute;left:12px;top:-64px;z-index:120;background:var(--yellow);color:var(--ink-dark);
  padding:10px 16px;border-radius:0 0 10px 10px;font-family:var(--font-mono);font-size:13px;font-weight:700;
  transition:top .16s ease}
.skip-link:focus{top:0}

.site-header{position:sticky;top:0;z-index:60;background:rgba(10,31,26,.95);
  border-bottom:1px solid var(--line-strong);backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px)}

.topline{background:var(--ink-dark);border-bottom:1px solid var(--line)}
.topline__inner{display:flex;align-items:center;justify-content:space-between;gap:20px;min-height:30px;
  font-family:var(--font-mono);font-size:11.5px;letter-spacing:.05em;color:var(--mist);overflow:hidden}
.topline__meta{display:flex;flex-wrap:nowrap;gap:18px;white-space:nowrap;color:var(--mist)}
.topline__meta--end{flex:0 0 auto}
.topline__key{color:var(--cyan)}
.topline__spot{color:var(--yellow)}
.topline__link{color:var(--mist);border-bottom:1px solid transparent}
.topline__link:hover{color:var(--cyan);border-bottom-color:var(--cyan)}

.header-inner{display:grid;grid-template-columns:auto minmax(0,1fr) auto;align-items:center;
  gap:clamp(12px,2vw,32px);min-height:66px;padding-block:10px}

.brand{position:relative;display:grid;gap:2px;line-height:1.15;padding-left:14px}
.brand::before{content:"";position:absolute;left:0;top:3px;bottom:3px;width:4px;border-radius:2px;
  background:linear-gradient(180deg,var(--cyan),var(--cyan-deep) 70%,transparent)}
.brand-line{font-weight:700;font-size:18px;letter-spacing:-.02em;color:var(--white)}
.brand-sub{font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;color:var(--mist)}
.brand:hover .brand-line{color:var(--cyan)}

.cmdnav{display:flex;justify-content:center;min-width:0}
.cmdnav-list{display:flex;align-items:center;gap:0}
.cmdnav-link{display:flex;align-items:baseline;gap:6px;padding:8px 11px;border-radius:var(--radius-s);
  border-bottom:2px solid transparent;color:rgba(244,242,234,.78);font-size:14.5px;
  transition:background-color .16s ease,color .16s ease,border-color .16s ease,transform .16s ease}
.cmdnav-num{font-family:var(--font-mono);font-size:11px;letter-spacing:.04em;color:var(--mist);font-variant-numeric:tabular-nums}
.cmdnav-link:hover{background:rgba(14,90,82,.42);color:var(--white);transform:translateY(-1px)}
.cmdnav-link[aria-current="page"]{color:var(--yellow);border-bottom-color:var(--yellow)}
.cmdnav-link[aria-current="page"] .cmdnav-num{color:var(--yellow)}
.cmdnav-foot{display:none}

.header-tools{display:flex;align-items:center;justify-content:flex-end;gap:10px}

.round-switch{position:relative}
.round-switch__summary{display:inline-flex;align-items:center;gap:8px;list-style:none;
  padding:7px 13px;border:1px solid var(--line-strong);border-radius:999px;background:rgba(14,90,82,.22);
  font-family:var(--font-mono);font-size:var(--fs-12);letter-spacing:.05em;color:var(--cyan);
  transition:background-color .16s ease,color .16s ease}
.round-switch__summary:hover{background:rgba(14,90,82,.5);color:var(--white)}
.round-switch__key{color:var(--mist)}
.round-switch__current{color:var(--yellow);font-weight:700}
.round-switch__caret{width:7px;height:7px;border-right:1.5px solid currentColor;border-bottom:1.5px solid currentColor;
  transform:rotate(45deg) translateY(-1px);transition:transform .16s ease}
.round-switch[open] .round-switch__caret{transform:rotate(225deg) translateY(-1px)}
.round-switch__panel{position:absolute;right:0;top:calc(100% + 10px);z-index:70;width:min(420px,84vw);
  background:var(--ink-dark);border:1px solid var(--line-strong);border-radius:var(--radius-m);
  padding:16px;box-shadow:0 24px 48px rgba(0,0,0,.5)}
.round-switch__hint{font-family:var(--font-mono);font-size:var(--fs-12);letter-spacing:.04em;color:var(--mist);margin-bottom:12px}
.round-grid{display:grid;grid-template-columns:repeat(8,minmax(0,1fr));gap:6px}
.round-chip{display:block;text-align:center;padding:5px 0;border-radius:6px;border:1px solid transparent;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.04em;color:var(--mist);
  transition:background-color .16s ease,color .16s ease,border-color .16s ease}
.round-chip:hover{background:rgba(14,90,82,.5);color:var(--white);border-color:var(--line-strong)}
.round-chip[data-current="true"]{background:var(--yellow);color:var(--ink-dark);font-weight:700}
.round-switch__all{display:block;margin-top:14px;font-family:var(--font-mono);font-size:var(--fs-12);letter-spacing:.04em;color:var(--cyan)}
.round-switch__all:hover{color:var(--yellow)}

.header-cta{font-size:13px;padding:9px 15px}

.nav-toggle{display:none;align-items:center;gap:9px;padding:7px 13px;border:1px solid var(--line-strong);
  border-radius:999px;color:var(--white);font-family:var(--font-mono);font-size:var(--fs-12);letter-spacing:.06em;
  transition:background-color .16s ease}
.nav-toggle:hover{background:rgba(14,90,82,.4)}
.nav-toggle__bars{display:grid;gap:4px;width:18px}
.nav-toggle__bars i{display:block;height:2px;border-radius:2px;background:currentColor;transition:transform .16s ease,opacity .16s ease}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(1){transform:translateY(6px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(2){opacity:0}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(3){transform:translateY(-6px) rotate(-45deg)}

.scroll-progress{position:absolute;left:0;right:0;bottom:-1px;height:2px;transform:scaleX(0);transform-origin:0 50%;
  background:linear-gradient(90deg,var(--cyan-deep),var(--cyan) 58%,var(--yellow));pointer-events:none;z-index:5}

/* ---------- 7. 页脚 ---------- */
.site-footer{position:relative;background:var(--ink-dark);border-top:1px solid var(--line-strong)}
.site-footer::before{content:"";position:absolute;left:0;right:0;top:0;height:60px;pointer-events:none;
  background:linear-gradient(90deg,rgba(35,224,200,.09),rgba(35,224,200,0) 62%);
  clip-path:polygon(0 0,100% 0,100% 100%,0 0)}
.footer-shell{position:relative;padding-block:clamp(40px,5vw,60px) 30px}
.footer-top{display:grid;grid-template-columns:1.5fr 1fr 1fr 1.4fr;gap:clamp(24px,3vw,40px)}
.footer-brand__note{margin-top:16px;font-size:13.5px;color:var(--mist);max-width:26em}
.brand--footer{display:grid;padding-left:14px}
.footer-col__title{position:relative;font-family:var(--font-mono);font-size:var(--fs-12);letter-spacing:.1em;
  color:var(--cyan);font-weight:400;margin-bottom:14px;padding-left:12px}
.footer-col__title::before{content:"";position:absolute;left:0;top:.42em;width:6px;height:6px;border-radius:1px;
  background:var(--cyan);transform:rotate(12deg)}
.footer-list li+li{margin-top:8px}
.footer-link{font-size:14.5px;color:rgba(244,242,234,.8);border-bottom:1px solid transparent}
.footer-link:hover{color:var(--cyan);border-bottom-color:var(--cyan)}
.footer-list--plain li+li{margin-top:9px}
.footer-line{font-size:13.5px;color:var(--mist);line-height:1.8}
.footer-line .mono{color:rgba(244,242,234,.86);font-size:12.5px}
.footer-note-block{margin-top:clamp(28px,4vw,44px);padding-top:20px;border-top:1px solid var(--line)}
.footer-note{font-family:var(--font-mono);font-size:var(--fs-12);letter-spacing:.04em;color:rgba(157,180,174,.75)}
.footer-note+.footer-note{margin-top:8px}
.footer-bottom{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:14px 24px;
  margin-top:22px;padding-top:20px;border-top:1px solid var(--line)}
.footer-legal{display:flex;flex-wrap:wrap;gap:8px 18px}
.footer-legal a{font-family:var(--font-mono);font-size:var(--fs-12);letter-spacing:.04em;color:var(--mist)}
.footer-legal a:hover{color:var(--cyan)}
.footer-icp{font-size:var(--fs-12);color:var(--mist)}
.footer-copy{font-family:var(--font-mono);font-size:var(--fs-12);letter-spacing:.04em;color:rgba(157,180,174,.8)}

/* ---------- 8. 响应式 ---------- */
@media (max-width:1180px){
  .cmdnav-link{padding:8px 8px;font-size:14px}
}
@media (max-width:1024px){
  :root{--header-h:87px}
  .header-inner{grid-template-columns:auto auto;justify-content:space-between;min-height:56px}
  .header-cta{display:none}
  .nav-toggle{display:inline-flex}
  .cmdnav{position:absolute;top:100%;left:0;right:0;display:block;
    background:var(--ink-dark);border-bottom:1px solid var(--line-strong);
    padding:16px var(--pad) 24px;
    opacity:0;visibility:hidden;transform:translateY(-4px);pointer-events:none;
    transition:opacity .18s ease,transform .18s ease,visibility .18s ease;
    max-height:calc(100vh - var(--header-h));overflow-y:auto;box-shadow:0 24px 44px rgba(0,0,0,.5)}
  .cmdnav[data-open="true"]{opacity:1;visibility:visible;transform:none;pointer-events:auto}
  .cmdnav-list{display:block}
  .cmdnav-link{display:flex;align-items:center;gap:14px;padding:14px 10px;border-radius:0;
    border-bottom:1px solid var(--line);border-left:3px solid transparent;font-size:16px}
  .cmdnav-link:hover{transform:none;background:rgba(14,90,82,.32)}
  .cmdnav-link[aria-current="page"]{border-left-color:var(--yellow);border-bottom-color:var(--line);
    background:rgba(233,255,87,.06);padding-left:16px}
  .cmdnav-num{font-size:12px}
  .cmdnav-foot{display:flex;align-items:center;gap:18px;margin-top:20px}
  .cmdnav-meta{font-family:var(--font-mono);font-size:var(--fs-12);letter-spacing:.04em;color:var(--mist)}
  .cmdnav-meta:hover{color:var(--cyan)}
  .round-switch__panel{position:fixed;left:12px;right:12px;top:calc(var(--header-h) + 8px);
    width:auto;max-height:64vh;overflow-y:auto}
  .footer-top{grid-template-columns:1fr 1fr;gap:28px}
}
@media (max-width:860px){
  .footer-top{grid-template-columns:1fr 1fr}
}
@media (max-width:600px){
  body{font-size:16px}
  .topline__spot{display:none}
  .topline__meta{gap:12px}
  .header-inner{gap:10px}
  .brand-line{font-size:16px}
  .brand-sub{font-size:10px}
  .round-switch__summary{padding:6px 10px}
  .round-grid{grid-template-columns:repeat(6,minmax(0,1fr))}
  .footer-top{grid-template-columns:1fr}
  .footer-bottom{flex-direction:column;align-items:flex-start;gap:12px}
  .board__row{grid-template-columns:1fr;gap:4px}
  .index-item{grid-template-columns:48px minmax(0,1fr);gap:12px}
  .index-item__meta{grid-column:2;font-size:11px}
}

/* ---------- 9. 动效降级 ---------- */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation-duration:.01ms !important;animation-iteration-count:1 !important;transition-duration:.01ms !important}
  .card:hover,.btn--primary:hover,.btn--ghost:hover,.cmdnav-link:hover{transform:none}
  .scroll-progress{transition:none}
}