:root{color-scheme:light;--ink:#14253a;--ink-soft:#50677f;--blue:#1768b5;--blue-dark:#0f4f91;--blue-soft:#eaf3fd;--teal:#0d8a72;--paper:#fff;--canvas:#f6f9fd;--line:#dbe5f1;--shadow:0 18px 55px #1c4a7d17;--shell:min(1120px, calc(100% - 40px));font-synthesis:none;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif}*{box-sizing:border-box}html{scroll-behavior:smooth}body{background:var(--canvas);color:var(--ink);text-rendering:optimizelegibility;margin:0;line-height:1.6}a{color:var(--blue);text-underline-offset:3px}button,input{font:inherit}button:focus-visible,a:focus-visible,input:focus-visible,summary:focus-visible,[tabindex]:focus-visible{outline-offset:3px;outline:3px solid #1768b559}[hidden]{display:none!important}.page-shell{width:var(--shell);margin-inline:auto}.page-shell--reading{max-width:780px}.skip-link{z-index:20;color:#174f87;background:#fff;border-radius:999px;padding:5px 10px;font-size:.72rem;font-weight:800;text-decoration:none;position:absolute;top:8px;left:12px;box-shadow:0 4px 16px #14355824}.site-header{z-index:10;backdrop-filter:blur(14px);background:#f6f9fde6;border-bottom:1px solid #cfdcebd9;position:sticky;top:0}.site-header__inner{grid-template-columns:auto 1fr auto;align-items:center;gap:28px;min-height:76px;display:grid}.wordmark{color:var(--ink);letter-spacing:-.02em;align-items:center;gap:10px;font-weight:850;text-decoration:none;display:inline-flex}.wordmark__mark{background:var(--blue);color:#fff;border-radius:10px;place-items:center;width:34px;height:34px;font-size:1.2rem;display:grid;box-shadow:0 8px 18px #1768b538}.wordmark__muted{color:#668097;font-weight:650}.primary-nav{justify-content:center;gap:30px;display:flex}.primary-nav a{color:#465e76;justify-content:center;align-items:center;min-width:44px;min-height:44px;font-size:.9rem;font-weight:750;text-decoration:none;display:inline-flex}.primary-nav a:hover{color:var(--blue)}.header-action{color:var(--blue-dark);background:#e8f2fd;border-radius:10px;padding:10px 16px;font-size:.85rem;font-weight:800;text-decoration:none}.hero{background:radial-gradient(circle at 82% 12%,#2874c626,#0000 30%),radial-gradient(circle at 7% 70%,#0d8a7214,#0000 25%),linear-gradient(#f8fbff,#eef5fc);padding:clamp(70px,10vw,118px) 0 clamp(110px,14vw,165px);position:relative;overflow:hidden}.hero:after{content:"";border:1px solid #1768b51f;border-radius:50%;width:520px;height:520px;position:absolute;bottom:-200px;right:-100px;box-shadow:inset 0 0 0 70px #ffffff38}.hero__inner{z-index:1;grid-template-columns:minmax(0,1fr) minmax(260px,.62fr);align-items:center;gap:clamp(48px,8vw,110px);display:grid;position:relative}.hero__badge{color:#2d5d8f;background:#ffffffb8;border:1px solid #cbdff3;border-radius:999px;align-items:center;gap:8px;padding:7px 12px;font-size:.78rem;font-weight:800;display:inline-flex}.hero__badge span{color:#16a085;font-size:.62rem}.hero h1{letter-spacing:-.065em;max-width:790px;margin:20px 0;font-size:clamp(3.15rem,8vw,6.7rem);line-height:.92}.hero__lead{max-width:690px;color:var(--ink-soft);margin:0;font-size:clamp(1.05rem,2vw,1.3rem)}.hero__proof{color:#4c657d;flex-wrap:wrap;gap:20px;margin-top:28px;font-size:.84rem;font-weight:750;display:flex}.hero__proof span:before{content:"✓";color:var(--teal);margin-right:7px}.hero__motif{background:#ffffff8c;border:1px solid #fffc;border-radius:42% 58% 54% 46%/50% 40% 60% 50%;place-items:center;min-height:300px;display:grid;position:relative;transform:rotate(3deg);box-shadow:0 35px 80px #1e558e1f}.hero__number{color:#154f89;letter-spacing:-.08em;font-size:clamp(5rem,12vw,9rem);font-weight:900;line-height:1}.hero__percent{color:#19a288;font-size:4rem;font-weight:300;position:absolute;top:35px;right:48px}.hero__equals{color:#fff;background:#173c63;border-radius:999px;padding:8px 13px;font-size:1rem;font-weight:800;position:absolute;bottom:36px;right:34px}.home-calculator{z-index:2;width:var(--shell);margin:clamp(-95px,-8vw,-70px) auto 0;position:relative}.content-section{padding:clamp(70px,9vw,112px) 0}.content-section--white{background:#fff}.content-section--soft{background:#eef5fc}.section-heading{gap:10px;max-width:720px;margin-bottom:38px;display:grid}.section-heading--center{text-align:center;margin-inline:auto}.section-heading h2,.page-heading h1{letter-spacing:-.045em;margin:0;font-size:clamp(2rem,4vw,3.35rem);line-height:1.05}.section-heading p,.page-lead{color:var(--ink-soft);margin:0;font-size:1.05rem}.example-grid,.formula-grid{grid-template-columns:repeat(3,minmax(0,1fr));gap:18px;display:grid}.example-card,.formula-card,.feature-card,.guide-card{border:1px solid var(--line);background:var(--paper);border-radius:16px;box-shadow:0 12px 35px #1e4b7a0f}.example-card{align-content:start;min-height:230px;padding:24px;display:grid}.example-card p,.formula-card p,.feature-card p,.guide-card p{color:var(--ink-soft)}.example-card strong{margin:10px 0 24px;font-size:1.55rem}.example-card button{width:fit-content;color:var(--blue);cursor:pointer;background:0 0;border:0;margin-top:auto;padding:0;font-weight:800}.feature-grid{grid-template-columns:repeat(4,minmax(0,1fr));gap:18px;display:grid}.feature-card{padding:24px}.feature-card__symbol{background:var(--blue-soft);width:44px;height:44px;color:var(--blue);border-radius:12px;place-items:center;font-weight:900;display:grid}.feature-card h3,.formula-card h3,.guide-card h3{margin:18px 0 5px}.feature-card p,.formula-card p,.guide-card p{margin:0}.step-list{grid-template-columns:repeat(3,minmax(0,1fr));gap:28px;padding:0;list-style:none;display:grid}.step-list li{grid-template-columns:auto 1fr;gap:16px;display:grid}.step-list>li>span{width:48px;height:48px;color:var(--blue);border:1px solid #bfd5ec;border-radius:50%;place-items:center;font-size:.8rem;font-weight:900;display:grid}.step-list h3{margin:0 0 6px}.step-list p{color:var(--ink-soft);margin:0}.formula-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.formula-card{padding:26px}.formula-card code{color:#174d82;white-space:normal;background:#eef4fa;border-radius:10px;margin:12px 0;padding:14px 16px;font-size:.92rem;display:block}.formula-card a,.guide-card a{margin-top:18px;font-weight:800;text-decoration:none;display:inline-block}.related-grid{gap:12px;display:grid}.related-card{border:1px solid var(--line);color:var(--ink);background:#fff;border-radius:14px;grid-template-columns:auto 1fr auto;align-items:center;gap:20px;padding:20px 22px;text-decoration:none;transition:transform .16s,box-shadow .16s;display:grid}.related-card:hover{box-shadow:var(--shadow);transform:translateY(-2px)}.related-card>span{color:#8aa0b7;font-size:.76rem;font-weight:900}.related-card h3,.related-card p{margin:0}.related-card p{color:var(--ink-soft);font-size:.9rem}.related-card>strong{color:var(--blue)}.faq-list{border-top:1px solid var(--line);max-width:820px;margin-inline:auto}.faq-list details{border-bottom:1px solid var(--line)}.faq-list summary{cursor:pointer;justify-content:space-between;align-items:center;gap:20px;min-height:68px;font-weight:800;list-style:none;display:flex}.faq-list summary::-webkit-details-marker{display:none}.faq-list summary span{color:var(--blue);font-size:1.4rem}.faq-list details[open] summary span{transform:rotate(45deg)}.faq-list details p{color:var(--ink-soft);margin:-4px 0 24px}.guide-grid{grid-template-columns:repeat(3,minmax(0,1fr));gap:18px;display:grid}.guide-card{padding:24px}.guide-card__meta{color:#66819d;text-transform:uppercase;font-size:.78rem;font-weight:800}.home-cta{color:#fff;background:#143b63;border-radius:22px;grid-template-columns:1fr auto;align-items:center;gap:28px;padding:clamp(28px,5vw,52px);display:grid;box-shadow:0 24px 70px #113a632e}.home-cta h2{margin:0 0 6px;font-size:clamp(1.7rem,3vw,2.55rem)}.home-cta p{color:#cbdcec;margin:0}.home-cta a{color:#174f87;background:#fff;border-radius:11px;padding:13px 20px;font-weight:850;text-decoration:none}.page-heading{padding:64px 0 34px}.content-page-header{border-bottom:1px solid var(--line);background:radial-gradient(circle at 85% 20%,#1768b51a,#0000 28%),linear-gradient(#f9fcff,#eef5fc);padding:clamp(58px,8vw,92px) 0 clamp(44px,6vw,68px)}.content-page-header h1{letter-spacing:-.06em;margin:10px 0 16px;font-size:clamp(2.55rem,7vw,5rem);line-height:.98}.content-page-header p:last-child{max-width:720px;color:var(--ink-soft);margin:0;font-size:clamp(1.05rem,2vw,1.25rem)}.article-body{padding:clamp(54px,8vw,90px) 0}.article-body>section{margin-top:58px;scroll-margin-top:100px}.article-body>section:first-child,.article-body>.article-toc+section{margin-top:0}.article-body h2{letter-spacing:-.035em;margin:0 0 15px;font-size:clamp(1.7rem,3.5vw,2.45rem);line-height:1.15}.article-body h3{margin:30px 0 10px;font-size:1.18rem}.article-body p,.article-body li{color:#3e566e;font-size:1.02rem}.article-body li+li{margin-top:8px}.article-body code:not(.formula-card code){color:#174d82;overflow-wrap:anywhere;background:#eaf2fa;border-radius:7px;max-width:100%;padding:5px 9px;font-family:ui-monospace,SFMono-Regular,Consolas,monospace;display:inline-block}.article-toc{border:1px solid var(--line);background:#fff;border-radius:13px;grid-template-columns:auto repeat(4,1fr);align-items:center;gap:12px 18px;margin-bottom:52px;padding:18px 20px;font-size:.82rem;display:grid}.article-toc a{color:#4d6984;font-weight:700;text-decoration:none}.info-note{border-left:4px solid var(--blue);color:#35536f;background:#edf5fd;border-radius:0 12px 12px 0;margin:26px 0;padding:18px 20px}.example-answer{background:#effbf7;border-radius:10px;padding:13px 16px;color:#0b6d59!important}.equation-line{border:1px solid var(--line);color:#174d82;background:#fff;border-radius:12px;flex-wrap:wrap;align-items:center;gap:12px;width:fit-content;margin:24px 0;padding:16px 20px;font-family:ui-monospace,SFMono-Regular,Consolas,monospace;font-weight:750;display:flex}.article-action,.contact-link{background:var(--blue);color:#fff;border-radius:10px;padding:12px 18px;font-weight:800;text-decoration:none;display:inline-flex}.guide-index{gap:18px;display:grid}.guide-index article{border:1px solid var(--line);background:#fff;border-radius:16px;padding:28px;box-shadow:0 12px 35px #1e4b7a0d}.guide-index article>span{color:#68829c;letter-spacing:.08em;text-transform:uppercase;font-size:.77rem;font-weight:850}.guide-index h2{margin:10px 0}.guide-index p{margin:0}.guide-index a{margin-top:18px;font-weight:800;text-decoration:none;display:inline-block}.check-list{padding:0;list-style:none}.check-list li{padding-left:28px;position:relative}.check-list li:before{content:"✓";color:var(--teal);font-weight:900;position:absolute;left:0}.contact-card{border:1px solid var(--line);background:#fff;border-radius:16px;padding:26px}.tool-workspace{padding:12px 0 72px}.article-section h2{letter-spacing:-.035em;margin:8px 0 14px;font-size:clamp(1.8rem,4vw,2.7rem)}.article-section>p:not(.eyebrow){color:var(--ink-soft);font-size:1.03rem}.article-section .formula-card{margin-top:28px}.worked-example-grid{grid-template-columns:repeat(3,minmax(0,1fr));gap:18px;display:grid}.worked-example{border:1px solid var(--line);background:#fff;border-radius:16px;align-content:start;min-height:210px;padding:24px;display:grid}.worked-example h3{margin:0 0 18px}.worked-example code{color:#174d82;white-space:normal;background:#eef4fa;border-radius:9px;padding:12px 14px}.worked-example strong{color:var(--teal);margin-top:18px}.breadcrumbs ol{color:#6b8198;flex-wrap:wrap;gap:8px;margin:0 0 26px;padding:0;font-size:.8rem;list-style:none;display:flex}.breadcrumbs li{gap:8px;display:flex}.breadcrumbs a{color:#4f6b86}.site-footer{background:#eef4fa;border-top:1px solid #cbd9e8;margin-top:100px;padding:60px 0 24px}.site-footer__grid{grid-template-columns:1.5fr repeat(3,1fr);gap:48px;display:grid}.site-footer__grid>div:first-child p{max-width:300px;color:var(--ink-soft)}.site-footer h2{letter-spacing:.1em;text-transform:uppercase;margin:0 0 14px;font-size:.78rem}.site-footer__grid>div:not(:first-child){flex-direction:column;gap:9px;display:flex}.site-footer__grid a:not(.wordmark){color:#4b6279;align-items:center;min-width:44px;min-height:44px;font-size:.88rem;text-decoration:none;display:inline-flex}.site-footer__bottom{color:#6c8195;border-top:1px solid #cfdeec;justify-content:space-between;gap:20px;margin-top:50px;padding-top:22px;font-size:.78rem;display:flex}@media (width<=900px){.site-header__inner{grid-template-columns:1fr auto}.primary-nav{grid-area:2/1/auto/-1;justify-content:flex-start;padding-bottom:14px;overflow-x:auto}.hero__inner{grid-template-columns:1fr}.hero__motif{display:none}.feature-grid,.site-footer__grid,.article-toc{grid-template-columns:repeat(2,minmax(0,1fr))}.article-toc strong{grid-column:1/-1}}@media (width<=680px){:root{--shell:min(100% - 24px, 1120px)}.site-header{position:static}.site-header__inner{min-height:66px}.wordmark__muted,.header-action{display:none}.primary-nav{gap:12px}.wordmark{min-height:44px}.site-footer__grid>div:not(:first-child){gap:0}.hero{padding-top:56px}.hero h1{font-size:clamp(3.1rem,18vw,4.7rem)}.hero__proof{gap:7px;display:grid}.example-grid,.formula-grid,.guide-grid,.feature-grid,.step-list,.worked-example-grid,.site-footer__grid,.home-cta{grid-template-columns:1fr}.site-footer__bottom{flex-direction:column}.article-toc{grid-template-columns:1fr}}@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,:before,:after{scroll-behavior:auto!important;transition-duration:.01ms!important;animation-duration:.01ms!important}}