@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;500;600;700&family=Righteous&display=swap');

:root{
  --ink:#171f26;
  --ink-2:#1c262e;
  --ink-3:#212d36;
  --blue:#c8e0f4;
  --pink:#f5e0e8;
  --txt:#e9f1f7;
  --muted:#a4b7c5;
  --line:rgba(200,224,244,.14);
  --raise:-6px -6px 16px rgba(200,224,244,.07), 8px 8px 22px rgba(0,0,0,.6);
  --raise-sm:-3px -3px 8px rgba(200,224,244,.06), 4px 4px 12px rgba(0,0,0,.55);
  --press:inset 4px 4px 10px rgba(0,0,0,.5), inset -4px -4px 10px rgba(200,224,244,.08);
  --glass:linear-gradient(145deg, rgba(200,224,244,.12), rgba(245,224,232,.05));
  --r:16px;
  --wrap:1180px;
}

*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  margin:0;
  background-color:var(--ink);
  background-image:
    radial-gradient(circle at 12% 4%, rgba(200,224,244,.08), transparent 44%),
    radial-gradient(circle at 86% 92%, rgba(245,224,232,.07), transparent 46%);
  background-attachment:fixed;
  color:var(--txt);
  font-family:Poppins,-apple-system,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  font-size:17px;
  line-height:1.8;
  overflow-x:hidden;
}
body.lock{overflow:hidden}
img{display:block;max-width:100%;height:auto}
a{color:var(--blue);text-decoration:none}
a:hover{color:var(--pink)}
p{margin:0 0 1em}
h1,h2,h3,h4{margin:0 0 .5em;font-family:Righteous,Poppins,sans-serif;font-weight:400;line-height:1.24;letter-spacing:.012em}
h1{font-size:clamp(1.9rem,5.4vw,3.1rem)}
h2{font-size:clamp(1.38rem,3vw,1.9rem);color:var(--pink)}
h3{font-size:1.2rem;color:var(--blue)}
small{display:block;margin-bottom:.35em;font-size:.9rem;letter-spacing:.17em;color:var(--blue);font-family:Righteous,Poppins,sans-serif}

.skip{position:absolute;left:16px;top:-70px;z-index:90;padding:10px 16px;border-radius:12px;background:var(--ink-2);box-shadow:var(--raise)}
.skip:focus{top:12px}

/* 顶栏 */
.top{position:sticky;top:0;z-index:50;background:rgba(23,31,38,.94);backdrop-filter:blur(16px);border-bottom:1px solid var(--line)}
.top-row{display:flex;justify-content:center;align-items:center;padding:14px 18px 2px}
.brand{display:inline-flex;align-items:center;gap:10px;min-height:44px;padding:4px;font-family:Righteous,Poppins,sans-serif;font-size:1.16rem;color:var(--txt)}
.brand:hover{color:var(--pink)}
.brand-name{letter-spacing:.02em}
.mark{display:grid;place-items:center;width:30px;height:30px;border-radius:10px;background:linear-gradient(145deg,var(--blue),var(--pink));box-shadow:var(--raise-sm);color:var(--ink);font-family:Righteous,Poppins,sans-serif;font-size:.9rem;line-height:1}
.top-tools{display:flex;gap:10px;align-items:center;width:100%;max-width:var(--wrap);margin:0 auto;padding:8px 18px 14px}
.burger{display:inline-flex;align-items:center;gap:9px;min-height:46px;padding:10px 16px;border:0;border-radius:14px;background:var(--glass);color:var(--txt);font:inherit;font-size:1rem;box-shadow:var(--raise-sm);cursor:pointer;transition:transform .15s ease, box-shadow .15s ease}
.burger:active{transform:scale(.97);box-shadow:var(--press)}
.burger-bar{width:18px;height:2px;border-radius:2px;background:var(--blue);box-shadow:0 6px 0 var(--blue),0 -6px 0 var(--blue)}
.find{flex:1 1 auto;display:flex;min-width:0}
.find input{width:100%;min-height:46px;padding:10px 16px;border:0;border-radius:14px;background:var(--ink-2);color:var(--txt);font:inherit;font-size:1rem;box-shadow:var(--press)}
.find input::placeholder{color:var(--muted)}
.find input:focus{outline:2px solid rgba(200,224,244,.4);outline-offset:2px}

/* 全屏菜单 */
.menu{position:fixed;inset:0;z-index:45;display:flex;flex-direction:column;gap:16px;padding:152px 18px 40px;overflow-y:auto;background:radial-gradient(circle at 18% 6%, rgba(200,224,244,.16), transparent 48%), var(--ink);opacity:0;visibility:hidden;transform:translateY(-10px);transition:opacity .28s ease, transform .28s ease, visibility .28s ease}
.menu.open{opacity:1;visibility:visible;transform:none}
.menu-head{display:flex;align-items:center;justify-content:space-between;gap:12px;width:100%;max-width:var(--wrap);margin:0 auto}
.menu-brand{font-family:Righteous,Poppins,sans-serif;color:var(--pink);letter-spacing:.04em}
.menu-close{min-height:46px;padding:10px 20px;border:0;border-radius:14px;background:var(--glass);color:var(--txt);font:inherit;box-shadow:var(--raise-sm);cursor:pointer}
.menu-close:active{box-shadow:var(--press)}
.menu-nav{display:grid;gap:10px;width:100%;max-width:var(--wrap);margin:0 auto}
.menu-link{display:flex;align-items:center;min-height:54px;padding:13px 20px;border-radius:16px;background:var(--glass);box-shadow:var(--raise-sm);color:var(--txt);font-size:1.02rem;transition:transform .15s ease, box-shadow .15s ease}
.menu-link:active{transform:scale(.99);box-shadow:var(--press)}
.menu-empty{display:block;width:100%;max-width:var(--wrap);margin:0 auto;color:var(--muted)}

/* 首屏 */
.hero{position:relative;display:grid;gap:22px;width:100%;max-width:var(--wrap);margin:0 auto;padding:26px 18px 36px;scroll-margin-top:130px;background-image:radial-gradient(circle, rgba(200,224,244,.17) 1px, transparent 1.5px);background-size:22px 22px;background-position:-8px -8px}
.hero-art{order:-1}
.hero-figs{position:relative;margin:0;aspect-ratio:4/3;border-radius:22px;overflow:hidden;background:var(--ink-2);box-shadow:var(--raise)}
.hero-img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;opacity:0;transition:opacity .8s ease}
.hero-img.is-on{opacity:1}
.blob{aspect-ratio:4/3;border-radius:22px;background:radial-gradient(circle at 32% 28%, rgba(200,224,244,.55), transparent 58%), radial-gradient(circle at 72% 76%, rgba(245,224,232,.5), transparent 60%), var(--ink-2);box-shadow:var(--raise)}
.hero-copy{text-align:center}
.hero-copy h1{margin:0;text-shadow:0 2px 22px rgba(200,224,244,.22)}

/* 主体 */
.page{display:grid;gap:22px;width:100%;max-width:var(--wrap);margin:0 auto;padding:0 18px 52px}
.prose{min-width:0}
.prose > section{padding:clamp(18px,3vw,32px);margin-bottom:18px;border-radius:18px;background:var(--glass);box-shadow:var(--raise);backdrop-filter:blur(6px);scroll-margin-top:132px}
.prose > section:last-child{margin-bottom:0}
.prose p:last-child,.prose li:last-child{margin-bottom:0}
.prose ul,.prose ol{padding-left:1.25em}
.prose li{margin:.35em 0}
.prose img{margin:1em 0;border-radius:14px;box-shadow:var(--raise-sm)}
.prose blockquote{margin:1em 0;padding:14px 18px;border-radius:14px;background:rgba(200,224,244,.06);box-shadow:var(--press);color:var(--muted)}
.prose blockquote p:last-child{margin-bottom:0}
.prose table{width:100%;border-collapse:collapse;font-size:.98rem}
.prose th,.prose td{padding:10px;border-bottom:1px solid var(--line);text-align:left;vertical-align:top}
.prose code{font-family:ui-monospace,Menlo,Consolas,monospace;font-size:.94em;background:rgba(200,224,244,.1);padding:1px 6px;border-radius:8px}
.lede h2{font-size:clamp(1.2rem,2.6vw,1.6rem)}
.lede p{color:var(--muted);margin-bottom:0}

/* 侧栏 */
.rail{align-self:start;display:grid;gap:8px;padding:20px;border-radius:18px;background:var(--glass);box-shadow:var(--raise)}
.rail h2{font-size:1.16rem;margin-bottom:.3em}
.rail-nav{display:grid;gap:7px}
.rail-link{display:flex;align-items:center;min-height:46px;padding:11px 13px;border-radius:13px;background:rgba(200,224,244,.05);box-shadow:var(--raise-sm);color:var(--txt);transition:transform .15s ease, box-shadow .15s ease}
.rail-link:active{transform:scale(.98);box-shadow:var(--press)}
.to-top{justify-self:start;display:inline-flex;align-items:center;min-height:46px;margin-top:8px;padding:10px 16px;border-radius:14px;background:rgba(200,224,244,.05);box-shadow:var(--raise-sm);color:var(--pink)}

/* 页脚 */
.foot{margin-top:14px;padding:36px 18px 18px;border-top:1px solid var(--line);background:linear-gradient(180deg, rgba(200,224,244,.06), transparent 46%)}
.foot-cols{display:grid;gap:26px;width:100%;max-width:var(--wrap);margin:0 auto}
.foot-brand .brand{justify-content:flex-start}
.foot-desc{color:var(--muted);font-size:.98rem;margin-bottom:0}
.foot dl{margin:0}
.foot dt{margin-bottom:6px;font-family:Righteous,Poppins,sans-serif;color:var(--blue);letter-spacing:.05em}
.foot dd{margin:0;color:var(--muted)}
.foot dd a{display:inline-flex;align-items:center;min-height:42px;padding:6px 0;color:var(--txt)}
.foot-end{max-width:var(--wrap);margin:28px auto 0;padding-top:16px;border-top:1px solid var(--line);text-align:center;color:var(--muted);font-size:.94rem}
.foot-end p{margin:0}

/* 动效 */
.js .reveal{opacity:0;transform:translateY(14px)}
.js .reveal.in{opacity:1;transform:none;transition:opacity .55s ease, transform .55s ease}

@media (min-width:760px){
  .page{padding-top:32px}
  .hero{grid-template-columns:1.02fr .98fr;align-items:center;gap:34px;min-height:100svh;padding:44px 24px}
  .hero-art{order:0}
  .hero-copy{text-align:center}
  .menu-head,.menu-nav,.menu-empty{max-width:680px}
  .foot-cols{grid-template-columns:1.7fr 1fr 1fr 1fr;gap:30px}
}
@media (min-width:1000px){
  .page{grid-template-columns:minmax(0,1fr) 296px;align-items:start}
  .hero{padding:56px 24px}
}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .js .reveal{opacity:1;transform:none}
  .hero-img{transition:none}
  .burger,.menu-link,.rail-link,.menu-close{transition:none}
}

button[aria-expanded]{min-width:44px;min-height:44px}