:root{--bg:#f7f8fa;--bg-alt:#eef1f5;--surface:#ffffff;--text:#0f172a;--muted:#475569;--line:#dde3ea;--accent:#059669;--accent-2:#0284c7;--accent-soft:rgba(5, 150, 105, 0.1);--hero-bg:#0b1220;--hero-text:#e8eef6;--hero-muted:#9fb0c6;--radius:14px;--max:1120px}@media(prefers-color-scheme:dark){:root{--bg:#0b1220;--bg-alt:#0f1829;--surface:#121d31;--text:#e8eef6;--muted:#9fb0c6;--line:#1f2c44;--accent:#34d399;--accent-2:#38bdf8;--accent-soft:rgba(52, 211, 153, 0.12);--hero-bg:#070d18}}*,*::before,*::after{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:64px}body{margin:0;background:var(--bg);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,segoe ui,Roboto,helvetica neue,pingfang sc,microsoft yahei,sans-serif;font-size:17px;line-height:1.6;-webkit-font-smoothing:antialiased}a{color:inherit}.wrap{max-width:var(--max);margin:0 auto;padding:0 24px}@media(max-width:600px){.wrap{padding:0 16px}}header.site{position:sticky;top:0;z-index:10;background:color-mix(in srgb,var(--hero-bg) 88%,transparent);backdrop-filter:saturate(140%)blur(10px);-webkit-backdrop-filter:saturate(140%)blur(10px);border-bottom:1px solid rgba(255,255,255,6%);color:var(--hero-text)}header.site .wrap{display:flex;align-items:center;justify-content:space-between;height:64px}.brand{display:flex;align-items:center;gap:10px;text-decoration:none;font-weight:700;letter-spacing:-.01em}nav.primary{display:flex;gap:28px;font-size:15px}nav.primary a{text-decoration:none;color:var(--hero-muted);transition:color .15s}nav.primary a:hover,nav.primary a.active{color:var(--hero-text)}nav.primary a.active{box-shadow:inset 0 -2px #34d399}.menu-toggle{display:none;width:40px;height:40px;border-radius:10px;background:0 0;border:1px solid rgba(255,255,255,.18);color:var(--hero-text);align-items:center;justify-content:center;cursor:pointer}@media(max-width:720px){.menu-toggle{display:inline-flex}nav.primary{display:none;position:absolute;top:64px;left:0;right:0;flex-direction:column;gap:0;padding:8px 16px 16px;background:var(--hero-bg);border-bottom:1px solid rgba(255,255,255,8%)}nav.primary.open{display:flex}nav.primary a{padding:12px 0;font-size:16px;border-top:1px solid rgba(255,255,255,6%)}nav.primary a:first-child{border-top:0}}.hero{position:relative;overflow:hidden;background:radial-gradient(1200px 600px at 85% 20%,rgba(56,189,248,.14),transparent 60%),radial-gradient(900px 500px at 10% 90%,rgba(52,211,153,.12),transparent 60%),var(--hero-bg);color:var(--hero-text);padding:96px 0 112px}.hero .wrap{position:relative;z-index:1;display:grid;grid-template-columns:1.15fr .85fr;gap:48px;align-items:center}@media(max-width:900px){.hero .wrap{grid-template-columns:1fr}.hero-art{display:none}.hero{padding:72px 0 80px}}.eyebrow{display:inline-flex;align-items:center;gap:8px;font-size:13px;font-weight:600;letter-spacing:.08em;text-transform:uppercase;color:#34d399;padding:6px 12px;border:1px solid rgba(52,211,153,.35);border-radius:999px;background:rgba(52,211,153,8%)}.eyebrow .dot{width:7px;height:7px;border-radius:50%;background:#34d399;box-shadow:0 0 rgba(52,211,153,.6);animation:pulse 2.4s infinite}@keyframes pulse{0%{box-shadow:0 0 rgba(52,211,153,.55)}70%{box-shadow:0 0 0 10px rgba(52,211,153,0)}100%{box-shadow:0 0 rgba(52,211,153,0)}}.hero h1{font-size:clamp(36px,5.4vw,60px);line-height:1.08;letter-spacing:-.025em;margin:22px 0 12px;font-weight:750}.hero h1 .grad{background:linear-gradient(90deg,#34d399,#38bdf8);-webkit-background-clip:text;background-clip:text;color:transparent}.hero .zh{font-size:20px;color:var(--hero-muted);letter-spacing:.12em;margin:0 0 22px}.hero p.lede{font-size:19px;color:var(--hero-muted);max-width:560px;margin:0 0 16px}.hero .x-note{font-size:15px;color:var(--hero-muted);max-width:560px;margin:0 0 32px}.hero .x-note b{display:inline-grid;place-items:center;width:24px;height:24px;margin-right:6px;border-radius:6px;background:rgba(52,211,153,.14);color:#34d399;font-weight:800}.cta{display:flex;flex-wrap:wrap;gap:12px}.btn{display:inline-flex;align-items:center;gap:8px;padding:13px 22px;border-radius:10px;font-weight:600;font-size:15px;text-decoration:none;transition:transform .15s,background .15s,border-color .15s}.btn:hover{transform:translateY(-1px)}.btn-primary{background:#34d399;color:#062018}.btn-primary:hover{background:#4ade9f}.hero-art svg{width:100%;height:auto;max-width:420px;display:block;margin-left:auto}.orbit{transform-origin:200px 200px;animation:spin 40s linear infinite}.orbit.r2{animation-duration:55s;animation-direction:reverse}.orbit.r3{animation-duration:70s}@keyframes spin{to{transform:rotate(360deg)}}@media(prefers-reduced-motion:reduce){.orbit,.eyebrow .dot{animation:none}html{scroll-behavior:auto}}section{padding:96px 0}section.alt{background:var(--bg-alt)}@media(max-width:600px){section{padding:64px 0}}.section-head{max-width:680px;margin-bottom:48px}.kicker{font-size:13px;font-weight:700;letter-spacing:.1em;text-transform:uppercase;color:var(--accent);margin:0 0 10px}h2{font-size:clamp(28px,3.6vw,40px);line-height:1.15;letter-spacing:-.02em;margin:0 0 14px}.section-head p{color:var(--muted);margin:0;font-size:18px}.grid{display:grid;gap:20px}.grid.cols-3{grid-template-columns:repeat(3,1fr)}.grid.cols-2{grid-template-columns:repeat(2,1fr)}@media(max-width:900px){.grid.cols-3{grid-template-columns:repeat(2,1fr)}}@media(max-width:620px){.grid.cols-3,.grid.cols-2{grid-template-columns:1fr}}.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:28px;transition:border-color .2s,transform .2s}.card:hover{border-color:color-mix(in srgb,var(--accent) 50%,var(--line));transform:translateY(-2px)}.card h3{margin:16px 0 8px;font-size:19px;letter-spacing:-.01em}.card p{margin:0;color:var(--muted);font-size:15.5px}.icon{width:44px;height:44px;border-radius:11px;display:grid;place-items:center;background:var(--accent-soft);color:var(--accent)}.icon svg{width:22px;height:22px}.tags{display:flex;flex-wrap:wrap;gap:6px;margin-top:16px}.tag{font-size:12.5px;font-weight:600;padding:3px 9px;border-radius:6px;background:var(--bg-alt);color:var(--muted);border:1px solid var(--line);font-family:ui-monospace,SFMono-Regular,Menlo,monospace}.nuclide-group+.nuclide-group{margin-top:32px}.nuclide-group h3{font-size:15px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;margin:0 0 12px}.nuclide-group h3 span{font-weight:500;letter-spacing:0;text-transform:none;color:var(--muted);margin-left:8px}.radionuclides{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}@media(max-width:900px){.radionuclides{grid-template-columns:repeat(2,1fr)}}.iso.next{border-style:dashed}.iso{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:16px;position:relative}.iso .mass{font-size:13px;color:var(--muted);font-weight:600;vertical-align:super}.iso .sym{font-size:30px;font-weight:750;letter-spacing:-.02em}.iso .use{font-size:13px;color:var(--muted);margin-top:4px;line-height:1.4}.iso .kind{position:absolute;top:12px;right:12px;font-size:12.5px;font-weight:700;text-transform:uppercase;letter-spacing:.06em;color:var(--accent-2)}.iso .kind.t{color:var(--accent)}.lens{display:grid;grid-template-columns:1fr 1fr;gap:20px}@media(max-width:780px){.lens{grid-template-columns:1fr}}.lens .card{padding:32px}.lens h3{margin-top:0;font-size:22px}.lens ul{margin:14px 0 0;padding:0;list-style:none}.lens li{padding:10px 0 10px 28px;position:relative;color:var(--muted);border-top:1px solid var(--line);font-size:15.5px}.lens li:first-child{border-top:0}.lens li::before{content:"";position:absolute;left:4px;top:18px;width:9px;height:9px;border-radius:50%;border:2px solid var(--accent)}.lens .card.cn li::before{border-color:var(--accent-2)}.flag{font-size:13px;font-weight:700;color:var(--accent);letter-spacing:.08em;text-transform:uppercase}.lens .card.cn .flag{color:var(--accent-2)}footer{padding:48px 0;border-top:1px solid var(--line);color:var(--muted);font-size:14px}footer .wrap{display:flex;flex-wrap:wrap;gap:16px 32px;justify-content:space-between;align-items:center}footer .brand{color:var(--text)}footer .links{display:flex;gap:18px}footer .links a{text-decoration:none}footer .links a:hover{color:var(--text)}footer .disclaimer{flex-basis:100%;font-size:13px;opacity:.85;margin:0}.page-hero{background:radial-gradient(900px 420px at 85% 0%,rgba(56,189,248,.13),transparent 60%),radial-gradient(700px 380px at 5% 100%,rgba(52,211,153,.1),transparent 60%),var(--hero-bg);color:var(--hero-text);padding:64px 0 56px}.page-hero h1{font-size:clamp(32px,4.6vw,50px);line-height:1.12;letter-spacing:-.025em;margin:18px 0 12px;font-weight:750;max-width:860px}.page-hero .page-desc{color:var(--hero-muted);font-size:18px;margin:0;max-width:680px}.page-hero .post-meta{color:var(--hero-muted);margin-top:6px}.page-hero .cta{margin-top:28px}@media(max-width:600px){.page-hero{padding:48px 0 40px}}.page-body{padding:56px 0 88px}@media(max-width:600px){.page-body{padding:40px 0 64px}}.post-meta{display:flex;flex-wrap:wrap;gap:6px 8px;font-size:14px;color:var(--muted)}.post-list{display:grid;gap:20px}.post-card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);transition:border-color .2s,transform .2s;overflow:hidden;display:flex;flex-direction:column}.post-card:hover{border-color:color-mix(in srgb,var(--accent) 50%,var(--line));transform:translateY(-2px)}.post-card>a{display:grid;grid-template-columns:1fr;text-decoration:none;color:inherit;flex:1}.post-card>a.has-cover{grid-template-columns:1fr 240px}@media(max-width:700px){.post-card>a.has-cover{grid-template-columns:1fr}.post-card .card-cover{order:-1;aspect-ratio:16/8}}.post-card .card-body{padding:26px 28px 18px}.post-card .card-cover{width:100%;height:100%;object-fit:cover;display:block;background:var(--bg-alt)}.post-card h2{font-size:22px;line-height:1.3;letter-spacing:-.01em;margin:10px 0 8px}.post-card p{margin:0;color:var(--muted);font-size:15.5px}.post-card .tags{margin:0;padding:0 28px 24px}.post-list.compact{grid-template-columns:repeat(3,1fr)}.post-list.compact .post-card h2{font-size:19px}@media(max-width:900px){.post-list.compact{grid-template-columns:1fr}}.empty{color:var(--muted)}a.tag{text-decoration:none;transition:color .15s,border-color .15s}a.tag:hover{color:var(--accent);border-color:color-mix(in srgb,var(--accent) 45%,var(--line))}.tag em{font-style:normal;opacity:.6;margin-left:4px}.section-foot{margin-top:28px}.text-link{color:var(--accent);font-weight:600;text-decoration:none}.text-link:hover{text-decoration:underline}.pagination{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-top:40px}.pagination .page-num{color:var(--muted);font-size:14px}.btn-outline{border:1px solid var(--line);background:var(--surface);color:var(--text)}.btn-outline:hover{border-color:color-mix(in srgb,var(--accent) 50%,var(--line))}.post{max-width:740px;margin:0 auto}.post-cover{margin:0 0 40px}.post-cover img{width:100%;border-radius:var(--radius);border:1px solid var(--line);display:block}.prose{font-size:18px;line-height:1.75}.prose>:first-child{margin-top:0}.prose h2,.prose h3,.prose h4{line-height:1.3;letter-spacing:-.015em;margin:2em 0 .6em}.prose h2{font-size:28px}.prose h3{font-size:22px}.prose h4{font-size:18px}.prose p{margin:0 0 1.25em}.prose a{color:var(--accent-2);text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px}.prose a:hover{text-decoration-thickness:2px}.prose ul,.prose ol{padding-left:1.4em;margin:0 0 1.25em}.prose li{margin-bottom:.4em}.prose li::marker{color:var(--accent)}.prose blockquote{margin:1.6em 0;padding:4px 0 4px 20px;border-left:3px solid var(--accent);color:var(--muted)}.prose blockquote p:last-child{margin-bottom:0}.prose code{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.88em;background:var(--bg-alt);border:1px solid var(--line);border-radius:5px;padding:.1em .35em}.prose pre{margin:1.6em 0;padding:18px 20px;border-radius:12px;overflow-x:auto;font-size:14.5px;line-height:1.6;border:1px solid var(--line)}.prose pre code{background:0 0;border:0;padding:0;font-size:inherit}.prose img{max-width:100%;height:auto;border-radius:10px}.prose hr{border:0;border-top:1px solid var(--line);margin:2.5em 0}.prose table{width:100%;border-collapse:collapse;font-size:15.5px;margin:1.6em 0}@media(max-width:700px){.prose table{display:block;overflow-x:auto}}.prose th,.prose td{text-align:left;padding:10px 14px;border-bottom:1px solid var(--line);vertical-align:top}.prose th{background:var(--bg-alt);font-weight:650}.prose sup,.prose sub{line-height:0}.prose ol.refs{font-size:15px;line-height:1.6;color:var(--muted);padding-left:1.8em}.prose ol.refs li{margin-bottom:.7em;padding:2px 6px;border-radius:6px;transition:background .3s}.prose ol.refs li:target,.prose ol.refs li.is-target{background:var(--accent-soft);color:var(--text)}.prose ol.refs a{word-break:break-word}.post-tags{margin-top:40px;padding-top:24px;border-top:1px solid var(--line)}.post-nav{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-top:40px}@media(max-width:620px){.post-nav{grid-template-columns:1fr}}.post-nav a{display:flex;flex-direction:column;gap:4px;padding:18px 20px;text-decoration:none;background:var(--surface);border:1px solid var(--line);border-radius:12px;transition:border-color .2s}.post-nav a:hover{border-color:color-mix(in srgb,var(--accent) 50%,var(--line))}.post-nav small{color:var(--muted);font-size:13px}.post-nav span{font-weight:600;line-height:1.4}.post-nav a.next{text-align:right}.terms-cloud{display:flex;flex-wrap:wrap;gap:10px}.terms-cloud .tag{font-size:14px;padding:6px 12px}.topic-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(190px,1fr));gap:16px}.topic-card{position:relative;display:flex;flex-direction:column;gap:8px;padding:22px 20px 20px;text-decoration:none;color:inherit;overflow:hidden;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);transition:border-color .2s,transform .2s}.topic-card::before{content:"";position:absolute;inset:0 0 auto 0;height:3px;background:linear-gradient(90deg,var(--accent),var(--accent-2))}.topic-card:hover{border-color:color-mix(in srgb,var(--accent) 50%,var(--line));transform:translateY(-2px)}.topic-card h3{margin:0;font-size:18px;letter-spacing:-.01em}.topic-card p{margin:0;color:var(--muted);font-size:14.5px;line-height:1.5;flex:1}.topic-count{font-size:13px;font-weight:600;color:var(--accent);margin-top:4px}.subhead{font-size:20px;margin:48px 0 18px;letter-spacing:-.01em}.topic-chips{display:flex;flex-wrap:wrap;gap:8px;margin-top:26px}.topic-chips a{font-size:14px;font-weight:600;text-decoration:none;color:var(--hero-muted);padding:6px 14px;border-radius:999px;border:1px solid rgba(255,255,255,.16);transition:color .15s,border-color .15s,background .15s}.topic-chips a:hover{color:var(--hero-text);border-color:rgba(255,255,255,.4)}.topic-chips a.active{background:#34d399;border-color:#34d399;color:#062018}a.eyebrow{text-decoration:none;transition:background .15s}a.eyebrow:hover{background:rgba(52,211,153,.16)}.post-meta .core-label{color:var(--accent);font-weight:650}.notice{margin:0 0 32px;padding:14px 18px;font-size:14.5px;line-height:1.55;background:color-mix(in srgb,#f59e0b 10%,var(--surface));border:1px solid color-mix(in srgb,#f59e0b 40%,var(--line));border-left-width:4px;border-radius:10px;color:var(--text)}.post .notice{max-width:740px}