:root{
  --deep-sea:#061826;
  --deep-water:#0A2C3D;
  --brand:#0E7C9E;
  --bright-cyan:#27C7D9;
  --pale-cyan:#D8F4F7;
  --coral:#FF6B4A;
  --lime:#C9F04B;
  --mist:#F5FBFC;
  --ink:#08131B;
  --slate:#6E8C9A;
  --radius-lg:28px;
  --radius-sm:12px;
  --radius-pill:999px;
  --shell-w:1280px;
  --gutter:clamp(20px,4vw,64px);
  --ease:cubic-bezier(0.22,1,0.36,1);
  --font-display:"Barlow Condensed","Source Han Sans SC","Noto Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"Noto Sans SC","Source Han Sans SC",-apple-system,"PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  --font-mono:"IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{margin:0;font-family:var(--font-body);font-size:16px;line-height:1.75;color:var(--ink);background:var(--mist);-webkit-font-smoothing:antialiased;overflow-x:hidden}
img,svg{display:block;max-width:100%}
ul,ol{list-style:none;margin:0;padding:0}
button{font:inherit;color:inherit;background:none;border:0}
h1,h2,h3,h4,p,figure{margin:0}
h1,h2,h3,h4{font-family:var(--font-display);font-weight:800;letter-spacing:-.01em;line-height:1.12;color:var(--ink)}
h1{font-size:clamp(2.6rem,6vw,5.4rem);line-height:1.02}
h2{font-size:clamp(1.8rem,3vw,2.8rem)}
h3{font-size:clamp(1.15rem,1.7vw,1.42rem);letter-spacing:0}
a{color:var(--brand);text-decoration:none}
:where(a,button,summary,[tabindex]):focus-visible{outline:2px solid var(--lime);outline-offset:3px;border-radius:8px}
.shell{width:min(100% - var(--gutter) * 2,var(--shell-w));margin-inline:auto}
.site-main{display:block}
.section{padding-block:clamp(56px,7vw,110px)}
.skip-link{position:fixed;top:8px;left:8px;z-index:100;padding:12px 20px;border-radius:var(--radius-pill);background:var(--lime);color:var(--deep-sea);font-family:var(--font-mono);font-size:12px;letter-spacing:.08em;transform:translateY(-180%);transition:transform .22s var(--ease)}
.skip-link:focus,.skip-link:focus-visible{transform:translateY(0)}
.scroll-progress{position:fixed;inset:0 0 auto 0;height:3px;z-index:80;background:rgba(6,24,38,.22);pointer-events:none}
.scroll-progress-bar{display:block;height:100%;width:100%;transform:scaleX(0);transform-origin:0 50%;background:linear-gradient(90deg,var(--coral),var(--bright-cyan) 55%,var(--lime));transition:transform .12s linear}
.site-header{position:relative;z-index:40;isolation:isolate;background:var(--deep-sea);color:var(--mist)}
.site-header::before{content:"";position:absolute;inset:auto 0 0 0;height:150px;z-index:-1;pointer-events:none;background:linear-gradient(100deg,rgba(14,124,158,.38),rgba(6,24,38,0) 64%);clip-path:polygon(0 100%,100% 0,100% 100%)}
.header-strip{background:var(--deep-water);border-bottom:1px solid rgba(39,199,217,.16)}
.strip-inner{display:flex;align-items:center;justify-content:space-between;gap:18px;min-height:44px;padding-block:8px}
.strip-note{display:flex;align-items:center;gap:10px;font-family:var(--font-mono);font-size:11px;letter-spacing:.06em;color:rgba(245,251,252,.66)}
.signal-dot{width:7px;height:7px;border-radius:2px;flex:none;background:var(--lime);box-shadow:0 0 0 3px rgba(201,240,75,.18);animation:signal-pulse 2.6s var(--ease) infinite}
@keyframes signal-pulse{0%,100%{opacity:1}50%{opacity:.35}}
.strip-links{display:flex;gap:20px}
.strip-link{font-family:var(--font-mono);font-size:11px;letter-spacing:.06em;color:rgba(245,251,252,.72);padding-bottom:2px;border-bottom:1px solid transparent;transition:color .2s var(--ease),border-color .2s var(--ease)}
.strip-link:hover{color:var(--bright-cyan);border-color:var(--bright-cyan)}
.header-shell{position:relative}
.header-inner{display:flex;align-items:center;justify-content:space-between;gap:24px;padding-block:clamp(16px,2.2vw,26px)}
.brand{display:inline-flex;align-items:center;gap:14px;color:inherit;text-decoration:none}
.brand-mark{position:relative;width:38px;height:38px;flex:none;border-radius:13px;background:linear-gradient(150deg,var(--bright-cyan),var(--brand));box-shadow:0 12px 26px -14px rgba(39,199,217,.95)}
.brand-mark::before{content:"";position:absolute;left:8px;right:8px;top:12px;height:2px;border-radius:2px;background:var(--deep-sea);box-shadow:0 6px 0 var(--deep-sea),0 12px 0 rgba(6,24,38,.55);transform:rotate(-8deg)}
.brand-text{display:flex;flex-direction:column;gap:2px}
.brand-name{font-family:var(--font-display);font-size:1.375rem;font-weight:800;line-height:1.1;letter-spacing:.01em}
.brand-sub{font-family:var(--font-mono);font-size:10.5px;letter-spacing:.08em;color:rgba(245,251,252,.55)}
.header-tools{display:flex;align-items:center;gap:12px}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:14px 22px;border-radius:var(--radius-pill);border:1px solid transparent;font-family:var(--font-body);font-size:14px;font-weight:600;line-height:1;text-decoration:none;cursor:pointer;transition:background .2s var(--ease),color .2s var(--ease),border-color .2s var(--ease),transform .2s var(--ease)}
.btn-primary{background:var(--coral);color:var(--deep-sea)}
.btn-primary:hover{background:#FF8A6D;transform:translateY(-1px)}
.btn-ghost{background:transparent;color:var(--mist);border-color:rgba(245,251,252,.3)}
.btn-ghost:hover{border-color:var(--bright-cyan);color:var(--bright-cyan)}
.btn-quiet{background:var(--pale-cyan);color:var(--ink)}
.btn-quiet:hover{background:#EAFBFD}
.nav-toggle{display:none;align-items:center;gap:9px;padding:10px 16px;border-radius:var(--radius-pill);border:1px solid rgba(245,251,252,.28);background:rgba(245,251,252,.05);color:var(--mist);cursor:pointer;transition:border-color .2s var(--ease),background .2s var(--ease)}
.nav-toggle:hover{border-color:var(--bright-cyan);background:rgba(39,199,217,.12)}
.nav-toggle-bars{display:inline-flex;flex-direction:column;gap:4px;width:16px}
.nav-toggle-bars span{display:block;height:2px;border-radius:2px;background:currentColor;transition:transform .22s var(--ease),opacity .22s var(--ease)}
.site-header[data-open] .nav-toggle-bars span:first-child{transform:translateY(3px) rotate(45deg)}
.site-header[data-open] .nav-toggle-bars span:last-child{transform:translateY(-3px) rotate(-45deg)}
.nav-toggle-label{font-family:var(--font-mono);font-size:11px;letter-spacing:.12em}
.site-nav{border-top:1px solid rgba(245,251,252,.1);background:rgba(6,24,38,.55)}
.nav-inner{display:flex;align-items:center;justify-content:space-between;gap:20px}
.nav-list{display:flex;flex-wrap:wrap;align-items:center;gap:clamp(16px,2.6vw,40px)}
.nav-item{display:block}
.nav-link{position:relative;display:flex;align-items:baseline;gap:8px;padding-block:15px;color:rgba(245,251,252,.78);font-size:15px;text-decoration:none;transition:color .2s var(--ease)}
.nav-index{font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;color:var(--slate);transition:color .2s var(--ease)}
.nav-label{font-weight:500}
.nav-link::after{content:"";position:absolute;left:0;right:0;bottom:7px;height:2px;border-radius:2px;background:var(--coral);transform:scaleX(0);transform-origin:left center;transition:transform .22s var(--ease)}
.nav-link:hover{color:var(--mist)}
.nav-link:hover::after{transform:scaleX(1)}
.nav-link[aria-current="page"]{color:var(--mist)}
.nav-link[aria-current="page"]::after{transform:scaleX(1)}
.nav-link[aria-current="page"] .nav-index{color:var(--coral)}
.nav-quick{display:none;flex-wrap:wrap;gap:10px}
.nav-quick-link{display:inline-flex;padding:9px 15px;border-radius:var(--radius-pill);border:1px solid rgba(39,199,217,.36);color:var(--bright-cyan);font-family:var(--font-mono);font-size:11px;letter-spacing:.06em;text-decoration:none;transition:background .2s var(--ease),color .2s var(--ease)}
.nav-quick-link:hover{background:rgba(39,199,217,.16);color:var(--mist)}
.site-footer{position:relative;margin-top:clamp(64px,8vw,120px);background:var(--deep-water);color:rgba(245,251,252,.78);overflow:hidden;isolation:isolate}
.footer-cut{position:absolute;top:-6px;left:-4%;width:108%;height:12px;z-index:2;background:linear-gradient(90deg,var(--coral),var(--bright-cyan) 56%,var(--lime));transform:rotate(-0.55deg);transform-origin:left center}
.footer-watermark{position:absolute;right:clamp(-6px,1vw,10px);bottom:-0.14em;z-index:0;font-family:var(--font-display);font-size:clamp(84px,17vw,230px);font-weight:800;line-height:.8;letter-spacing:.02em;color:rgba(39,199,217,.08);pointer-events:none;user-select:none}
.footer-main{position:relative;z-index:1;display:grid;grid-template-columns:minmax(0,1.1fr) minmax(0,1.5fr);gap:clamp(32px,5vw,72px);padding-block:clamp(52px,7vw,92px) clamp(32px,4vw,56px)}
.footer-brand{display:flex;flex-direction:column;gap:18px;max-width:36ch}
.brand-footer .brand-name{font-size:1.25rem}
.brand-footer .brand-mark{width:34px;height:34px;border-radius:12px}
.footer-note{font-size:12.5px;line-height:1.75;color:rgba(245,251,252,.5);max-width:36ch}
.footer-contact{display:flex;flex-direction:column;gap:12px;padding-top:16px;border-top:1px solid rgba(245,251,252,.12)}
.contact-row{display:flex;flex-wrap:wrap;align-items:baseline;gap:10px;font-size:14px;line-height:1.6}
.contact-key{min-width:56px;font-family:var(--font-mono);font-size:10.5px;letter-spacing:.14em;color:var(--slate)}
.contact-value{color:var(--mist);word-break:break-word}
.copy-btn{align-self:flex-start;margin-top:4px;padding:9px 16px;border-radius:var(--radius-pill);border:1px solid rgba(39,199,217,.45);background:rgba(39,199,217,.1);color:var(--bright-cyan);font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;cursor:pointer;transition:background .2s var(--ease),color .2s var(--ease),border-color .2s var(--ease)}
.copy-btn:hover{background:rgba(39,199,217,.22);color:var(--mist)}
.copy-btn[data-copied="true"]{border-color:var(--lime);color:var(--lime)}
.copy-btn[data-copied="false"]{border-color:var(--coral);color:var(--coral)}
.footer-links{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:clamp(20px,3vw,40px);align-content:start}
.footer-col{display:flex;flex-direction:column;gap:12px}
.footer-col-title{font-family:var(--font-mono);font-size:10.5px;font-weight:500;letter-spacing:.16em;color:var(--bright-cyan)}
.footer-col-list{display:flex;flex-direction:column;gap:10px}
.footer-link{width:fit-content;font-size:14.5px;color:rgba(245,251,252,.76);text-decoration:none;border-bottom:1px solid transparent;transition:color .2s var(--ease),border-color .2s var(--ease)}
.footer-link:hover{color:var(--lime);border-color:var(--lime)}
.footer-meta{position:relative;z-index:1;display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:14px;padding-block:20px 30px;border-top:1px solid rgba(245,251,252,.12);font-family:var(--font-mono);font-size:11px;letter-spacing:.06em;color:rgba(245,251,252,.5)}
.footer-legal{color:rgba(245,251,252,.5)}
.footer-copy{color:rgba(245,251,252,.5)}
.back-top{position:fixed;right:clamp(14px,3vw,32px);bottom:clamp(14px,3vw,32px);z-index:60;display:inline-flex;align-items:center;gap:8px;padding:12px 18px;border-radius:var(--radius-pill);border:1px solid rgba(39,199,217,.45);background:var(--deep-sea);color:var(--mist);font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;cursor:pointer;opacity:0;transform:translateY(10px);pointer-events:none;transition:opacity .24s var(--ease),transform .24s var(--ease),background .2s var(--ease)}
.back-top.is-visible{opacity:1;transform:none;pointer-events:auto}
.back-top:hover{background:var(--brand);border-color:var(--bright-cyan)}
.breadcrumb{font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;color:var(--slate)}
.breadcrumb-list{display:flex;flex-wrap:wrap;align-items:center;gap:8px}
.breadcrumb-item{display:flex;align-items:center;gap:8px}
.breadcrumb-item::after{content:"/";color:rgba(110,140,154,.55)}
.breadcrumb-item:last-child::after{display:none}
.breadcrumb-link{color:var(--brand)}
.breadcrumb-link:hover{text-decoration:underline}
.breadcrumb-current{color:var(--ink)}
.eyebrow{display:block;font-family:var(--font-mono);font-size:11px;letter-spacing:.16em;text-transform:uppercase;color:var(--brand)}
.lede{max-width:38ch;font-size:clamp(1.05rem,1.5vw,1.22rem);line-height:1.7;color:#27505F}
.prose{max-width:68ch}
.prose p{margin-bottom:1.1em}
.prose p:last-child{margin-bottom:0}
.prose a{color:var(--brand);text-decoration:underline;text-underline-offset:3px}
.prose ul,.prose ol{margin:0 0 1.1em;padding-left:1.2em;list-style:disc}
.prose li{margin-bottom:.4em}
.chapter{display:flex;align-items:flex-start;gap:clamp(12px,2vw,26px)}
.chapter-number{font-family:var(--font-display);font-size:clamp(2.6rem,6vw,5rem);font-weight:800;line-height:.82;letter-spacing:-.02em;color:var(--coral);font-variant-numeric:tabular-nums}
.chapter-title{font-size:clamp(1.3rem,2vw,1.8rem);line-height:1.2}
.pill{display:inline-flex;align-items:center;gap:8px;padding:7px 14px;border-radius:var(--radius-pill);border:1px solid rgba(14,124,158,.24);background:rgba(14,124,158,.12);color:var(--brand);font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;text-transform:uppercase}
.pill-coral{border-color:rgba(255,107,74,.36);background:rgba(255,107,74,.14);color:#C8381A}
.pill-lime{border-color:rgba(201,240,75,.55);background:rgba(201,240,75,.22);color:#3F5200}
.card{background:#fff;border:1px solid rgba(10,44,61,.09);border-radius:var(--radius-lg);padding:clamp(20px,3vw,32px)}
.card-dark{background:var(--deep-water);border-color:rgba(39,199,217,.22);color:rgba(245,251,252,.82)}
.card-dark h2,.card-dark h3,.card-dark h4{color:var(--mist)}
.card-dark a{color:var(--bright-cyan)}
.card-pale{background:var(--pale-cyan);border-color:rgba(10,44,61,.06);color:var(--ink)}
.grid{display:grid;gap:clamp(18px,2.6vw,34px)}
.grid-split{grid-template-columns:minmax(0,5fr) minmax(0,7fr)}
.grid-uneven{grid-template-columns:minmax(0,4fr) minmax(0,8fr)}
.media-frame{position:relative;overflow:hidden;aspect-ratio:4/3;border-radius:var(--radius-lg);background:linear-gradient(150deg,var(--deep-water),var(--brand) 74%)}
.media-frame::before{content:"";position:absolute;inset:0;background:repeating-linear-gradient(120deg,rgba(245,251,252,.08) 0 2px,transparent 2px 12px)}
.media-frame img{position:relative;z-index:1;width:100%;height:100%;object-fit:cover}
.media-frame--tall{aspect-ratio:3/4}
.media-frame--wide{aspect-ratio:16/9}
.media-frame--slant{clip-path:polygon(0 0,100% 0,100% 92%,0 100%)}
[data-reveal]{opacity:0;transform:translateY(16px);transition:opacity .32s var(--ease),transform .32s var(--ease)}
[data-reveal].is-in{opacity:1;transform:none}
@media (max-width:1024px){
  .footer-main{grid-template-columns:minmax(0,1fr);gap:clamp(28px,5vw,48px)}
  .footer-brand{max-width:none}
}
@media (max-width:899px){
  .nav-toggle{display:inline-flex}
  .btn-cta{display:none}
  .site-nav{display:grid;grid-template-rows:0fr;visibility:hidden;transition:grid-template-rows .28s var(--ease),visibility .28s var(--ease)}
  .site-header[data-open] .site-nav{grid-template-rows:1fr;visibility:visible}
  .nav-inner{flex-direction:column;align-items:stretch;min-height:0;overflow:hidden;gap:0}
  .nav-list{flex-direction:column;align-items:stretch;gap:0;padding-block:6px}
  .nav-link{justify-content:flex-start;padding-block:14px;border-bottom:1px solid rgba(245,251,252,.08)}
  .nav-link::after{left:0;right:auto;width:44px;bottom:9px}
  .nav-quick{display:flex;padding-block:16px 22px}
  .grid-split,.grid-uneven{grid-template-columns:minmax(0,1fr)}
  .footer-links{grid-template-columns:repeat(2,minmax(0,1fr));gap:26px 20px}
  .footer-meta{flex-direction:column;align-items:flex-start;gap:8px}
}
@media (max-width:560px){
  .strip-links{display:none}
  .strip-note{font-size:10px;letter-spacing:.04em}
  .brand-sub{display:none}
  .brand-mark{width:34px;height:34px;border-radius:12px}
  .footer-links{grid-template-columns:minmax(0,1fr)}
  .footer-watermark{font-size:clamp(72px,26vw,140px)}
  .back-top{padding:10px 14px;font-size:10px}
}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation-duration:.001ms !important;animation-iteration-count:1 !important;transition-duration:.001ms !important}
  [data-reveal]{opacity:1;transform:none}
  .scroll-progress-bar{transition:none}
  .btn-primary:hover{transform:none}
}