:root{--bt-ink:#0f172a;--bt-body:#263041;--bt-r:14px;--bt-r-lg:20px;--bt-r-xl:28px;--bt-shadow-sm:0 1px 2px rgba(15,23,42,.06);--bt-shadow:0 10px 30px -14px rgba(15,23,42,.16),0 2px 6px rgba(15,23,42,.05);--bt-shadow-lg:0 26px 60px -28px rgba(30,58,138,.32),0 8px 20px rgba(15,23,42,.08);--bt-ease:cubic-bezier(0.22,1,0.36,1);--bt-dur:0.4s}.bt-bc{border-bottom:1px solid var(--border);background:linear-gradient(var(--sky),#fff)}.bt-bc-in{max-width:1180px;margin:0 auto;padding:13px 20px;display:flex;flex-wrap:wrap;align-items:center;gap:8px;font-size:13px}.bt-bc-in,.bt-bc-in a{color:var(--ink-muted)}.bt-bc-in a{transition:color .18s var(--bt-ease)}.bt-bc-in a:hover{color:var(--primary)}.bt-bc-sep{color:#b8c2d6}.bt-bc-cur{color:var(--ink);font-weight:500;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;max-width:46ch}.bt-pill{display:inline-flex;align-items:center;gap:6px;padding:5px 12px 5px 10px;border-radius:999px;font-size:12.5px;font-weight:650;line-height:1;letter-spacing:.01em;background:color-mix(in srgb,currentColor 12%,#fff);border:1px solid color-mix(in srgb,currentColor 26%,transparent)}.bt-pill:before{content:"";width:6px;height:6px;border-radius:999px;background:currentColor;flex:none}.bt-article{max-width:1180px;margin:0 auto;padding:clamp(28px,5vw,52px) 20px 80px}.bt-art-grid{display:grid;grid-template-columns:1fr;gap:40px}@media (min-width:1000px){.bt-art-grid{grid-template-columns:minmax(0,1fr) 300px;gap:56px}}.bt-art-main{min-width:0}.bt-art-head{margin-bottom:clamp(24px,3.5vw,34px)}.bt-art-title{font-size:clamp(30px,4.7vw,47px);line-height:1.08;font-weight:800;letter-spacing:-.032em;color:var(--bt-ink);margin:18px 0 0;text-wrap:balance}.bt-art-lede{color:#45526a;font-size:clamp(17px,2.1vw,20px);line-height:1.55;font-weight:450;margin:20px 0 0;max-width:62ch;text-wrap:pretty}.bt-art-meta{display:flex;flex-wrap:wrap;align-items:center;gap:12px;margin-top:24px;padding-top:20px;border-top:1px solid var(--border);font-size:14px;font-weight:500;color:var(--ink-muted)}.bt-art-meta .bt-dot{color:#c3ccdb}.bt-art-cover{margin:0 0 clamp(28px,4vw,40px);border-radius:var(--bt-r-xl);overflow:hidden;aspect-ratio:16/9;background:var(--sky);box-shadow:var(--bt-shadow)}.bt-art-cover img{width:100%;height:100%;-o-object-fit:cover;object-fit:cover;display:block}.bt-prose{font-size:17.5px;line-height:1.78;color:var(--bt-body);max-width:72ch}.bt-prose>:first-child{margin-top:0}.bt-prose p{margin:0 0 22px;text-wrap:pretty}.bt-prose>p:first-of-type{font-size:19.5px;line-height:1.68;color:#1c2433}.bt-prose h2{font-size:clamp(24px,3vw,30px);font-weight:750;letter-spacing:-.022em;line-height:1.22;margin:52px 0 18px;text-wrap:balance}.bt-prose h2,.bt-prose h3{color:var(--bt-ink);scroll-margin-top:96px}.bt-prose h3{font-size:clamp(19px,2.2vw,21px);font-weight:700;letter-spacing:-.01em;margin:36px 0 12px}.bt-prose a{color:var(--primary);text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1.5px;text-decoration-color:color-mix(in srgb,var(--primary) 32%,transparent);transition:text-decoration-color .2s var(--bt-ease),color .2s var(--bt-ease)}.bt-prose a:hover{color:var(--primary-700);text-decoration-color:var(--primary-700)}.bt-prose ol,.bt-prose ul{margin:0 0 22px;padding-left:2px;list-style:none}.bt-prose ol>li,.bt-prose ul>li{position:relative;padding-left:30px;margin-bottom:11px}.bt-prose ul>li:before{content:"";position:absolute;left:4px;top:.62em;width:8px;height:8px;border-radius:2.5px;background:var(--primary);transform:translateY(-50%) rotate(45deg)}.bt-prose ol{counter-reset:bt-ol}.bt-prose ol>li{counter-increment:bt-ol}.bt-prose ol>li:before{content:counter(bt-ol);position:absolute;left:0;top:.1em;width:22px;height:22px;border-radius:7px;background:var(--sky);color:var(--primary);font-size:12px;font-weight:700;font-variant-numeric:tabular-nums;display:flex;align-items:center;justify-content:center}.bt-prose img{max-width:100%;height:auto;border-radius:16px;margin:10px 0 26px;box-shadow:var(--bt-shadow-sm)}.bt-prose figure{margin:0 0 26px}.bt-prose figcaption{font-size:13px;color:var(--ink-muted);text-align:center;margin-top:10px}.bt-prose blockquote{position:relative;margin:34px 0;padding:4px 0 4px 2px;font-size:clamp(19px,2.4vw,23px);line-height:1.5;font-weight:550;color:var(--bt-ink)}.bt-prose blockquote:before{content:"\201C";display:block;font-family:Georgia,Times New Roman,serif;font-size:3em;line-height:.5;color:var(--primary);opacity:.24;margin-bottom:6px}.bt-prose blockquote p{margin:0 0 10px}.bt-prose blockquote p:last-child{margin-bottom:0}.bt-prose table{width:100%;border-collapse:collapse;display:block;overflow-x:auto;margin:0 0 26px;font-size:15px;border:1px solid var(--border);border-radius:12px}.bt-prose thead{background:var(--sky)}.bt-prose td,.bt-prose th{border:1px solid var(--border);padding:11px 15px;text-align:left;vertical-align:top}.bt-prose th{font-weight:700;color:var(--ink);white-space:nowrap}.bt-toc-title{font-size:12px;font-weight:700;letter-spacing:.09em;text-transform:uppercase;color:var(--ink-muted);margin:0 0 14px}.bt-toc{list-style:none;margin:0;padding:0;counter-reset:bt-toc;position:relative}.bt-toc li{counter-increment:bt-toc}.bt-toc a{display:flex;gap:11px;padding:8px 0 8px 14px;margin-left:-1px;border-left:2px solid var(--border);color:var(--ink-muted);font-size:13.5px;line-height:1.45;transition:color .2s var(--bt-ease),border-color .2s var(--bt-ease)}.bt-toc a:hover{color:var(--ink);border-left-color:color-mix(in srgb,var(--primary) 45%,transparent)}.bt-toc a:before{content:counter(bt-toc,decimal-leading-zero);font-variant-numeric:tabular-nums;font-size:11px;font-weight:650;color:#aab4c6;padding-top:1px;transition:color .2s var(--bt-ease)}.bt-toc a.is-active{color:var(--primary-700);font-weight:600;border-left-color:var(--primary)}.bt-toc a.is-active:before{color:var(--primary)}.bt-art-side{display:none}@media (min-width:1000px){.bt-art-side{display:block}.bt-sticky{position:sticky;top:88px;display:flex;flex-direction:column;gap:22px}}.bt-side-box{padding:22px}.bt-side-box,.bt-toc-mobile{border:1px solid var(--border);border-radius:var(--bt-r);background:var(--surface)}.bt-toc-mobile{margin:0 0 30px;padding:0 18px}@media (min-width:1000px){.bt-toc-mobile{display:none}}.bt-toc-mobile summary{list-style:none;cursor:pointer;padding:16px 0;font-size:15px;font-weight:650;color:var(--ink);display:flex;align-items:center;justify-content:space-between}.bt-toc-mobile summary::-webkit-details-marker{display:none}.bt-toc-mobile summary .bt-chev{transition:transform .25s var(--bt-ease);color:var(--ink-muted)}.bt-toc-mobile[open] summary .bt-chev{transform:rotate(180deg)}.bt-toc-mobile .bt-toc{padding:0 0 14px}.bt-cta{position:relative;overflow:hidden;margin:48px 0 0;border-radius:var(--bt-r-xl);padding:clamp(28px,4vw,40px);color:#fff;background:radial-gradient(120% 140% at 100% 0,#38bdf8 0,#2563eb 42%,#1d4ed8 100%);box-shadow:var(--bt-shadow-lg)}.bt-cta:after{content:"";position:absolute;right:-60px;top:-60px;width:240px;height:240px;border-radius:999px;border:1.5px solid hsla(0,0%,100%,.14);pointer-events:none}.bt-cta-title{margin:0 0 10px;font-size:clamp(22px,3vw,27px);font-weight:800;letter-spacing:-.02em}.bt-cta p{margin:0 0 22px;font-size:15.5px;line-height:1.6;color:hsla(0,0%,100%,.9);max-width:48ch}.bt-cta-row{display:flex;flex-wrap:wrap;gap:12px}.bt-btn{display:inline-flex;align-items:center;gap:8px;padding:13px 24px;border-radius:12px;font-size:15px;font-weight:700;text-decoration:none;transition:transform .2s var(--bt-ease),box-shadow .2s var(--bt-ease),background .2s var(--bt-ease)}.bt-btn svg{transition:transform .25s var(--bt-ease)}.bt-btn-white{background:#fff;color:var(--primary);box-shadow:0 8px 20px -8px rgba(2,20,60,.5)}.bt-btn-white:hover{color:var(--primary-700);transform:translateY(-2px)}.bt-btn-white:hover svg{transform:translateX(3px)}.bt-btn-ghost{background:hsla(0,0%,100%,.12);color:#fff;border:1px solid hsla(0,0%,100%,.32)}.bt-btn-ghost:hover{background:hsla(0,0%,100%,.2);color:#fff}.bt-sidecard{position:relative;overflow:hidden;border-radius:var(--bt-r);padding:24px;color:#fff;background:radial-gradient(130% 130% at 100% 0,#38bdf8 0,#2563eb 50%,#1d4ed8 100%)}.bt-sidecard-title{margin:0 0 7px;font-size:17px;font-weight:800;letter-spacing:-.01em}.bt-sidecard p{margin:0 0 18px;font-size:13.5px;line-height:1.55;color:hsla(0,0%,100%,.92)}.bt-sidecard .bt-btn-white{width:100%;justify-content:center}.bt-related{margin-top:64px;padding-top:44px;border-top:1px solid var(--border)}.bt-related>h2{margin:0 0 26px;font-size:clamp(22px,3vw,27px);font-weight:800;letter-spacing:-.025em;color:var(--bt-ink)}.bt-related-grid{display:grid;grid-template-columns:1fr;gap:22px}@media (min-width:640px){.bt-related-grid{grid-template-columns:repeat(3,1fr)}}.bt-card{display:flex;flex-direction:column;background:var(--surface);border:1px solid var(--border);border-radius:var(--bt-r-lg);overflow:hidden;text-decoration:none;transition:transform var(--bt-dur) var(--bt-ease),box-shadow var(--bt-dur) var(--bt-ease),border-color var(--bt-dur) var(--bt-ease)}.bt-card:hover{transform:translateY(-4px);box-shadow:var(--bt-shadow-lg);border-color:transparent}.bt-card-cover{position:relative;aspect-ratio:16/10;overflow:hidden;background:var(--sky)}.bt-card-cover img{width:100%;height:100%;-o-object-fit:cover;object-fit:cover;display:block;transition:transform .55s var(--bt-ease)}.bt-card:hover .bt-card-cover img{transform:scale(1.06)}.bt-card-cover .bt-pill{position:absolute;top:12px;left:12px;background:hsla(0,0%,100%,.94);backdrop-filter:blur(4px);box-shadow:var(--bt-shadow-sm);border-color:transparent}.bt-card-body{display:flex;flex-direction:column;gap:10px;padding:22px;flex:1}.bt-card-title{margin:0;font-size:17.5px;font-weight:700;line-height:1.3;letter-spacing:-.015em;color:var(--bt-ink);display:-webkit-box;-webkit-line-clamp:3;-webkit-box-orient:vertical;overflow:hidden;text-wrap:balance;transition:color .2s var(--bt-ease)}.bt-card:hover .bt-card-title{color:var(--primary-700)}.bt-card-lead{margin:0;font-size:14px;line-height:1.55;color:var(--ink-muted);display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;flex:1}.bt-card-more{margin-top:6px;font-size:13.5px;font-weight:700;color:var(--primary);display:inline-flex;align-items:center;gap:6px}.bt-card-more svg{transition:transform .25s var(--bt-ease)}.bt-card:hover .bt-card-more svg{transform:translateX(4px)}.bt-featured{display:grid;grid-template-columns:1fr;background:var(--surface);border:1px solid var(--border);border-radius:var(--bt-r-xl);overflow:hidden;text-decoration:none;margin-bottom:28px;transition:transform var(--bt-dur) var(--bt-ease),box-shadow var(--bt-dur) var(--bt-ease),border-color var(--bt-dur) var(--bt-ease)}.bt-featured:hover{transform:translateY(-4px);box-shadow:var(--bt-shadow-lg);border-color:transparent}@media (min-width:780px){.bt-featured{grid-template-columns:1.15fr 1fr;align-items:stretch}}.bt-featured-cover{position:relative;overflow:hidden;aspect-ratio:16/10;background:var(--sky)}@media (min-width:780px){.bt-featured-cover{aspect-ratio:auto;min-height:340px}}.bt-featured-cover img{width:100%;height:100%;-o-object-fit:cover;object-fit:cover;display:block;transition:transform .6s var(--bt-ease)}.bt-featured:hover .bt-featured-cover img{transform:scale(1.05)}.bt-featured-body{display:flex;flex-direction:column;justify-content:center;gap:14px;padding:clamp(24px,3.5vw,40px)}.bt-featured-tag{display:flex;align-items:center;gap:10px}.bt-featured-kicker{font-size:12px;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:var(--ink-muted)}.bt-featured-title{margin:0;font-size:clamp(22px,3.2vw,31px);font-weight:800;line-height:1.14;letter-spacing:-.028em;color:var(--bt-ink);text-wrap:balance;display:-webkit-box;-webkit-line-clamp:3;-webkit-box-orient:vertical;overflow:hidden;transition:color .2s var(--bt-ease)}.bt-featured:hover .bt-featured-title{color:var(--primary-700)}.bt-featured-lead{margin:0;font-size:15.5px;line-height:1.6;color:var(--ink-muted);display:-webkit-box;-webkit-line-clamp:3;-webkit-box-orient:vertical;overflow:hidden}.bt-featured-more{margin-top:4px;font-size:14.5px;font-weight:700;color:var(--primary);display:inline-flex;align-items:center;gap:7px}.bt-featured-more svg{transition:transform .25s var(--bt-ease)}.bt-featured:hover .bt-featured-more svg{transform:translateX(4px)}.bt-listing{max-width:1180px;margin:0 auto;padding:0 20px 80px}.bt-list-hero{padding:clamp(40px,6vw,60px) 0 clamp(28px,3.5vw,38px);max-width:760px}.bt-list-kicker{display:inline-flex;align-items:center;gap:9px;font-size:14px;font-weight:600;color:var(--primary)}.bt-list-kicker:before{content:"";width:7px;height:7px;border-radius:999px;background:var(--primary)}.bt-list-hero h1{margin:14px 0 0;font-size:clamp(34px,5.6vw,56px);font-weight:800;letter-spacing:-.035em;line-height:1.02;color:var(--bt-ink);text-wrap:balance}.bt-list-hero p{margin:18px 0 0;font-size:clamp(16px,2vw,19px);line-height:1.55;color:var(--ink-muted);max-width:60ch;text-wrap:pretty}.bt-filters{position:sticky;top:68px;z-index:20;display:flex;gap:9px;overflow-x:auto;padding:14px 0;margin-bottom:6px;background:color-mix(in srgb,var(--bg,#f7f9fc) 88%,transparent);backdrop-filter:saturate(1.6) blur(10px);scrollbar-width:none;border-bottom:1px solid var(--border)}.bt-filters::-webkit-scrollbar{display:none}.bt-filter{flex:none;padding:9px 16px;border-radius:999px;border:1px solid var(--border);background:var(--surface);color:var(--ink);font-size:14px;font-weight:600;text-decoration:none;white-space:nowrap;transition:border-color .2s var(--bt-ease),color .2s var(--bt-ease),background .2s var(--bt-ease),transform .2s var(--bt-ease)}.bt-filter:hover{border-color:color-mix(in srgb,var(--primary) 50%,transparent);color:var(--primary);transform:translateY(-1px)}.bt-filter.is-active{background:var(--bt-ink);border-color:var(--bt-ink);color:#fff}.bt-cards{display:grid;grid-template-columns:1fr;gap:26px;padding-top:30px}@media (min-width:640px){.bt-cards{grid-template-columns:repeat(2,1fr)}}@media (min-width:1000px){.bt-cards{grid-template-columns:repeat(3,1fr)}}.bt-empty{padding:48px 0;color:var(--ink-muted);font-size:16px}@media (prefers-reduced-motion:reduce){.bt-btn,.bt-btn svg,.bt-card,.bt-card-cover img,.bt-card-more svg,.bt-card-title,.bt-featured,.bt-featured-cover img,.bt-featured-more svg,.bt-featured-title,.bt-filter,.bt-prose a,.bt-toc a,.bt-toc-mobile summary .bt-chev{transition:none!important}.bt-btn-white:hover,.bt-card:hover,.bt-card:hover .bt-card-cover img,.bt-featured:hover,.bt-featured:hover .bt-featured-cover img,.bt-filter:hover{transform:none!important}}