/* ===========================================================
   9博主站 · 共享样式表 /assets/site.css
   深空蓝数字控制室 · 霓虹青信号 · 珊瑚橙行动点
   =========================================================== */

/* ---------- 0. 变量 ---------- */
:root{
  --deep:#0A1830;
  --deep-2:#12294A;
  --cyan:#35E0C8;
  --cyan-dim:#1B9E8C;
  --coral:#FF6B4A;
  --cream:#F4EBDC;
  --ink:#1C1511;
  --grid:#223A5C;
  --slate:#7C8DA6;
  --signal:#FFC94A;

  --line:rgba(34,58,92,.78);
  --line-soft:rgba(34,58,92,.45);
  --text:#E4EAF4;

  --font-display:"Noto Sans SC","Source Han Sans SC",system-ui,-apple-system,"PingFang SC","Microsoft YaHei",sans-serif;
  --font-body:system-ui,-apple-system,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  --font-mono:ui-monospace,SFMono-Regular,Menlo,Consolas,"Courier New",monospace;

  --wrap:1280px;
  --gutter:clamp(18px,4vw,40px);
  --header-h:68px;
}

/* ---------- 1. Reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{
  -webkit-text-size-adjust:100%;
  scroll-behavior:smooth;
  scroll-padding-top:96px;
}
body,h1,h2,h3,h4,h5,h6,p,figure,blockquote,dl,dd,ul,ol,pre{margin:0}
ul,ol{padding:0;list-style:none}
button,input,select,textarea{font:inherit;color:inherit}
button{background:none;border:0;padding:0;cursor:pointer}
a{color:inherit;text-decoration:none}
img,svg,video{display:block;max-width:100%;height:auto}
table{border-collapse:collapse;width:100%}
:focus-visible{outline:2px solid var(--cyan);outline-offset:3px}

/* ---------- 2. 页面基底 ---------- */
body{
  min-height:100vh;
  background-color:var(--deep);
  background-image:
    radial-gradient(900px 540px at 78% -12%,rgba(53,224,200,.13),transparent 68%),
    radial-gradient(760px 460px at -8% 26%,rgba(255,107,74,.10),transparent 70%),
    linear-gradient(to right,var(--line-soft) 1px,transparent 1px),
    linear-gradient(to bottom,var(--line-soft) 1px,transparent 1px);
  background-size:auto,auto,72px 72px,72px 72px;
  background-repeat:no-repeat,no-repeat,repeat,repeat;
  color:var(--text);
  font-family:var(--font-body);
  font-size:17px;
  line-height:1.75;
  letter-spacing:.005em;
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
}
h1,h2,h3,h4{font-family:var(--font-display);font-weight:800;line-height:1.22;color:var(--cream)}
h1{font-weight:900;letter-spacing:-.025em;font-size:clamp(34px,5.4vw,64px);line-height:1.06}
h2{letter-spacing:-.02em;font-size:clamp(26px,3.4vw,40px)}
h3{font-size:19px;letter-spacing:-.01em}
p{max-width:78ch}
strong{color:var(--cream);font-weight:700}
.mono{font-family:var(--font-mono);letter-spacing:.06em}
.num{font-family:var(--font-display);font-weight:900;font-variant-numeric:tabular-nums;letter-spacing:-.03em;line-height:.92}

/* ---------- 3. 布局工具 ---------- */
.wrap{width:100%;max-width:var(--wrap);margin:0 auto;padding-left:var(--gutter);padding-right:var(--gutter)}
.section{padding:clamp(52px,7.5vw,110px) 0}
.rule{border:0;border-top:1px solid var(--line);margin:0}

.section-head{
  display:flex;flex-wrap:wrap;align-items:flex-end;justify-content:space-between;
  gap:16px 32px;margin-bottom:clamp(22px,4vw,44px);
  padding-bottom:18px;border-bottom:1px solid var(--line);
}
.section-title{font-family:var(--font-display);font-weight:900;font-size:clamp(26px,3.6vw,46px);line-height:1.08;letter-spacing:-.025em;color:var(--cream)}
.section-note{max-width:44ch;color:var(--slate);font-size:15px;line-height:1.72}

.eyebrow{
  display:inline-flex;align-items:center;gap:9px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.22em;
  color:var(--cyan);text-transform:uppercase;
}
.eyebrow::before{content:"";width:26px;height:2px;background:var(--coral);flex:none}

.lead{font-size:clamp(17px,1.35vw,20px);line-height:1.82;color:#D6E2F3;max-width:64ch}

.grid{display:grid;gap:clamp(16px,2.2vw,28px)}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid--4{grid-template-columns:repeat(4,minmax(0,1fr))}
.grid--split{grid-template-columns:minmax(0,1.15fr) minmax(0,.85fr)}

/* ---------- 4. 通用组件 ---------- */
.card{
  position:relative;
  background:var(--deep-2);
  border:1px solid var(--line);
  padding:clamp(18px,2.4vw,30px);
  transition:border-color .2s ease,transform .2s ease;
}
.card::before{
  content:"";position:absolute;left:-1px;top:-1px;width:14px;height:14px;
  border-left:2px solid var(--cyan);border-top:2px solid var(--cyan);
  pointer-events:none;
}
.card h3{color:var(--cream)}
.card p{margin-top:9px;color:var(--slate);font-size:15px;line-height:1.78}
.card:hover{border-color:var(--cyan-dim);transform:translateY(-2px)}

.tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:3px 10px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.12em;
  color:var(--cyan);background:rgba(53,224,200,.10);
  border:1px solid rgba(53,224,200,.35);
  white-space:nowrap;
}
.tag--coral{color:var(--coral);background:rgba(255,107,74,.10);border-color:rgba(255,107,74,.42)}
.tag--signal{color:var(--signal);background:rgba(255,201,74,.10);border-color:rgba(255,201,74,.42)}
.tag--slate{color:var(--slate);background:rgba(124,141,166,.10);border-color:rgba(124,141,166,.38)}

.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:9px;
  padding:13px 24px;
  font-family:var(--font-display);font-size:15px;font-weight:700;
  letter-spacing:.02em;line-height:1.2;
  border:1px solid transparent;border-radius:0;
  cursor:pointer;
  transition:background-color .18s ease,color .18s ease,border-color .18s ease,transform .18s ease;
}
.btn--primary{background:var(--coral);color:var(--deep)}
.btn--primary:hover{background:#FF8468;transform:translateY(-2px)}
.btn--ghost{border-color:var(--cyan);color:var(--cyan);background:rgba(53,224,200,.06)}
.btn--ghost:hover{background:rgba(53,224,200,.16)}
.btn--quiet{border-color:var(--line);color:var(--slate);background:rgba(18,41,74,.6)}
.btn--quiet:hover{color:var(--cream);border-color:var(--cyan-dim)}

.breadcrumb{
  display:flex;flex-wrap:wrap;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.08em;color:var(--slate);
}
.breadcrumb li{display:flex;align-items:center;gap:8px}
.breadcrumb li+li::before{content:"/";color:var(--grid)}
.breadcrumb a:hover{color:var(--cyan)}
.breadcrumb [aria-current="page"]{color:var(--cream)}

.prose{max-width:74ch;color:var(--text);font-size:17px;line-height:1.82}
.prose p+p{margin-top:1.05em}
.prose h2{margin:1.9em 0 .55em;font-size:clamp(22px,2.6vw,30px)}
.prose h3{margin:1.5em 0 .5em;color:var(--cream)}
.prose ul,.prose ol{margin:1em 0}
.prose li{position:relative;padding-left:20px;margin:.45em 0}
.prose li::before{content:"";position:absolute;left:0;top:.78em;width:9px;height:2px;background:var(--cyan)}
.prose a{color:var(--cyan);border-bottom:1px solid var(--cyan-dim)}
.prose blockquote{margin:1.4em 0;padding:14px 20px;border-left:3px solid var(--coral);background:rgba(18,41,74,.6);color:#D6E2F3}

.media-frame{
  position:relative;overflow:hidden;
  background:var(--deep-2);
  border:1px solid var(--line);
}
.media-frame img{width:100%;height:100%;object-fit:cover}
.media-frame::before{
  content:"";position:absolute;left:0;top:0;width:28px;height:28px;z-index:2;
  border-left:2px solid var(--cyan);border-top:2px solid var(--cyan);
  pointer-events:none;
}
.media-frame::after{
  content:"";position:absolute;inset:0;z-index:1;pointer-events:none;
  background:
    linear-gradient(140deg,rgba(53,224,200,.14),transparent 55%),
    linear-gradient(320deg,rgba(255,107,74,.12),transparent 52%);
}
.media-frame--wide{aspect-ratio:16/9}
.media-frame--square{aspect-ratio:1/1}
.media-frame--tall{aspect-ratio:3/4}
.media-frame--band{aspect-ratio:21/9}

.surface-light{
  background:var(--cream);
  color:var(--ink);
  border-top:1px solid var(--ink);
  border-bottom:1px solid var(--ink);
}
.surface-light h1,.surface-light h2,.surface-light h3,.surface-light .section-title{color:var(--ink)}
.surface-light p,.surface-light li,.surface-light .prose{color:#3A2E27}
.surface-light .section-note{color:#5C4A3E}
.surface-light .section-head{border-bottom-color:rgba(28,21,17,.22)}
.surface-light .eyebrow{color:#8A3B22}
.surface-light .tag{color:#0F5C52;background:rgba(27,158,140,.14);border-color:rgba(27,158,140,.45)}
.surface-light .card{background:#FBF6EC;border-color:rgba(28,21,17,.18)}
.surface-light .card p{color:#5C4A3E}

/* ---------- 5. 页头 ---------- */
.site-header{
  position:sticky;top:0;z-index:70;
  background:rgba(10,24,48,.94);
  border-bottom:1px solid var(--line);
  -webkit-backdrop-filter:blur(10px);
  backdrop-filter:blur(10px);
}
.header-edge{
  position:absolute;left:0;top:0;bottom:0;width:6px;pointer-events:none;
  background:linear-gradient(180deg,var(--coral) 0 22%,var(--cyan) 22% 66%,var(--signal) 66% 100%);
}
.header-progress{
  position:absolute;left:0;right:0;bottom:-1px;height:2px;
  background:linear-gradient(90deg,var(--cyan),var(--coral));
  transform:scaleX(0);transform-origin:0 50%;
  will-change:transform;pointer-events:none;
}
.header-inner{
  max-width:var(--wrap);margin:0 auto;
  min-height:var(--header-h);
  padding:8px var(--gutter) 8px calc(var(--gutter) + 10px);
  display:flex;align-items:center;gap:22px;
}
.brand{display:inline-flex;align-items:baseline;gap:11px;padding:4px 0;flex:none}
.brand-mark{
  font-family:var(--font-display);font-weight:900;font-size:25px;
  letter-spacing:-.03em;color:var(--cream);line-height:1;
}
.brand-mark::before{
  content:"";display:inline-block;width:9px;height:9px;margin-right:9px;
  background:var(--coral);transform:translateY(-2px) rotate(45deg);
}
.brand-sub{
  font-family:var(--font-mono);font-size:11px;letter-spacing:.16em;
  color:var(--slate);white-space:nowrap;
}

.site-nav{margin-left:auto}
.nav-list{display:flex;align-items:center;gap:2px}
.nav-item{display:flex}
.nav-link{
  position:relative;display:inline-flex;align-items:center;gap:7px;
  padding:9px 13px;
  font-family:var(--font-display);font-size:14px;font-weight:700;
  letter-spacing:.02em;color:var(--slate);
  border:1px solid transparent;border-radius:0;
  transition:color .18s ease,background-color .18s ease,border-color .18s ease;
}
.nav-idx{
  font-family:var(--font-mono);font-size:10px;letter-spacing:.08em;
  color:var(--cyan-dim);transition:color .18s ease;
}
.nav-link:hover{color:var(--cream);background:rgba(18,41,74,.9);border-color:var(--line)}
.nav-link:hover .nav-idx{color:var(--cyan)}
.nav-link[aria-current="page"]{background:var(--cyan);color:var(--deep);border-color:var(--cyan)}
.nav-link[aria-current="page"] .nav-idx{color:rgba(10,24,48,.62)}

.nav-toggle{display:none}

.skip-link{
  position:absolute;left:14px;top:-72px;z-index:99;
  padding:10px 18px;
  background:var(--coral);color:var(--deep);
  font-family:var(--font-display);font-size:14px;font-weight:700;letter-spacing:.04em;
  transition:top .18s ease;
}
.skip-link:focus{top:10px}

/* ---------- 6. 页脚 ---------- */
.site-footer{
  margin-top:clamp(64px,9vw,124px);
  background:var(--deep-2);
  border-top:1px solid var(--line);
  color:var(--cream);
}
.footer-band{
  position:relative;height:58px;overflow:hidden;
  border-bottom:1px solid var(--line);
  background:linear-gradient(180deg,rgba(53,224,200,.10),rgba(255,107,74,.04));
}
.footer-band::before{
  content:"";position:absolute;left:-6%;right:-6%;top:-70%;bottom:-70%;
  background:repeating-linear-gradient(76deg,transparent 0 26px,rgba(53,224,200,.20) 26px 27px);
  transform:skewY(-2.5deg);
}
.footer-band::after{
  content:"";position:absolute;left:0;right:0;bottom:12px;height:2px;
  background:linear-gradient(90deg,transparent,var(--cyan) 22%,var(--coral) 62%,transparent);
  opacity:.75;
}
.footer-inner{
  max-width:var(--wrap);margin:0 auto;
  padding:clamp(36px,5vw,64px) var(--gutter) clamp(28px,4vw,46px);
  display:grid;
  grid-template-columns:minmax(0,1.5fr) minmax(0,1fr) minmax(0,1.2fr);
  gap:clamp(24px,4vw,56px);
}
.footer-mark{
  font-family:var(--font-display);font-weight:900;
  font-size:clamp(30px,3.4vw,44px);letter-spacing:-.03em;line-height:1;
  color:var(--cream);
}
.footer-mark::after{
  content:"";display:block;width:54px;height:3px;margin-top:15px;
  background:linear-gradient(90deg,var(--coral),var(--cyan));
}
.footer-note{margin-top:14px;max-width:40ch;font-size:15px;line-height:1.78;color:var(--slate)}
.footer-note--muted{margin-top:10px;color:#5E6F88;font-size:14px}
.footer-nav-title{
  font-family:var(--font-mono);font-size:12px;letter-spacing:.2em;
  color:var(--cyan);margin-bottom:16px;
}
.footer-nav-list{display:grid;gap:10px}
.footer-link{
  position:relative;display:inline-block;padding-left:0;
  font-size:15px;color:var(--slate);
  transition:color .18s ease,padding-left .18s ease;
}
.footer-link::before{
  content:"";position:absolute;left:0;top:50%;width:0;height:1px;
  background:var(--coral);transition:width .18s ease;
}
.footer-link:hover{color:var(--cream);padding-left:16px}
.footer-link:hover::before{width:10px}
.footer-contact{display:grid;gap:0;align-content:start}
.contact-row{
  display:grid;grid-template-columns:56px minmax(0,1fr);
  gap:12px;align-items:baseline;
  padding:10px 0;border-bottom:1px dashed var(--line-soft);
}
.contact-row:first-of-type{border-top:1px dashed var(--line-soft)}
.contact-label{font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;color:var(--cyan-dim)}
.contact-value{font-size:15px;color:#D6E2F3;word-break:break-word}
.footer-legal{border-top:1px solid var(--line);background:rgba(10,24,48,.72)}
.footer-legal-inner{
  max-width:var(--wrap);margin:0 auto;
  padding:16px var(--gutter);
  display:flex;flex-wrap:wrap;gap:10px 24px;
  justify-content:space-between;align-items:center;
}
.footer-legal-text{font-family:var(--font-mono);font-size:12px;letter-spacing:.1em;color:var(--slate)}

/* ---------- 7. 滚动显现 ---------- */
.js-reveal [data-reveal]{opacity:0;transform:translateY(18px)}
.js-reveal [data-reveal].is-revealed{
  opacity:1;transform:none;
  transition:opacity .6s ease,transform .6s cubic-bezier(.22,.72,.28,1);
}

/* ---------- 8. 响应式 ---------- */
@media (max-width:1080px){
  .brand-sub{display:none}
}
@media (max-width:960px){
  .grid--3,.grid--4,.grid--split{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-inner{grid-template-columns:minmax(0,1fr) minmax(0,1fr)}
  .footer-brand{grid-column:1 / -1}
}
@media (max-width:900px){
  :root{--header-h:60px}
  .header-inner{padding:6px 14px 6px 20px;gap:12px}
  .header-edge{width:4px}
  .brand-mark{font-size:22px}
  .nav-toggle{
    display:inline-flex;align-items:center;gap:9px;
    margin-left:auto;padding:9px 13px;
    border:1px solid var(--line);
    background:rgba(18,41,74,.85);
    color:var(--cream);
    font-family:var(--font-mono);font-size:12px;letter-spacing:.14em;
  }
  .nav-toggle-label{color:var(--slate)}
  .nav-toggle-glyph{display:inline-flex;flex-direction:column;gap:3px;width:16px}
  .nav-toggle-glyph i{display:block;height:2px;background:var(--cyan);transition:transform .2s ease,opacity .2s ease}
  .site-header[data-nav-open] .nav-toggle-glyph i:nth-child(1){transform:translateY(5px) rotate(45deg)}
  .site-header[data-nav-open] .nav-toggle-glyph i:nth-child(2){opacity:0}
  .site-header[data-nav-open] .nav-toggle-glyph i:nth-child(3){transform:translateY(-5px) rotate(-45deg)}

  .site-nav{
    position:absolute;left:0;right:0;top:100%;
    margin-left:0;max-height:0;overflow:hidden;
    background:rgba(10,24,48,.985);
    border-bottom:1px solid var(--line);
    box-shadow:0 20px 44px rgba(0,0,0,.48);
    transition:max-height .28s ease;
  }
  .site-nav[data-open]{max-height:78vh;overflow-y:auto}
  .nav-list{flex-direction:column;align-items:stretch;gap:0;padding:6px 0 14px}
  .nav-item{border-bottom:1px solid var(--line-soft)}
  .nav-item:last-child{border-bottom:0}
  .nav-link{width:100%;padding:15px 22px;font-size:15px;justify-content:flex-start}
  .nav-link[aria-current="page"]{
    background:rgba(53,224,200,.14);color:var(--cyan);
    border-color:transparent;border-left:3px solid var(--cyan);
  }
  .nav-link[aria-current="page"] .nav-idx{color:var(--cyan)}
}
@media (max-width:620px){
  body{font-size:16px;background-size:auto,auto,48px 48px,48px 48px}
  .grid--2,.grid--3,.grid--4,.grid--split{grid-template-columns:minmax(0,1fr)}
  .footer-inner{grid-template-columns:minmax(0,1fr);gap:32px}
  .footer-legal-inner{flex-direction:column;align-items:flex-start;gap:6px}
  .contact-row{grid-template-columns:52px minmax(0,1fr)}
  .media-frame--band{aspect-ratio:16/9}
}

/* ---------- 9. 减少动态 ---------- */
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  .js-reveal [data-reveal]{opacity:1;transform:none}
  .card:hover{transform:none}
  .btn:hover{transform:none}
}