:root{--authority-blue:#2563eb;--authority-ink:#17181b;--authority-muted:#52555c;--authority-faint:#767a82;--authority-line:#e6e7ea;--authority-surface:#f6f7f9;--authority-soft:#eef4ff;--authority-radius:12px}
.authority-nav{position:sticky;top:0;z-index:100;border-bottom:1px solid var(--authority-line);background:rgba(255,255,255,.97);backdrop-filter:blur(10px);font-family:var(--sans,'Inter',system-ui,sans-serif)}
.authority-nav__inner{max-width:1080px;margin:0 auto;padding:10px 24px;display:flex;align-items:center;gap:24px}
.authority-brand{display:flex;align-items:center;gap:9px;color:var(--authority-ink);font-weight:700;font-size:16px;text-decoration:none;white-space:nowrap}
.authority-brand svg,.authority-footer__brand svg{width:25px;height:25px;flex:none;color:var(--authority-ink)}
.authority-links{margin-left:auto;display:flex;align-items:center;gap:3px}
.authority-links>a,.authority-menu>summary{display:block;padding:9px 11px;border-radius:8px;color:var(--authority-muted);font-size:14px;font-weight:600;text-decoration:none;cursor:pointer;list-style:none;white-space:nowrap}
.authority-menu>summary::-webkit-details-marker{display:none}
.authority-menu>summary::after{content:"";display:inline-block;width:6px;height:6px;margin:0 0 3px 7px;border-right:1.5px solid currentColor;border-bottom:1.5px solid currentColor;transform:rotate(45deg)}
.authority-links>a:hover,.authority-menu>summary:hover,.authority-links .current{background:var(--authority-soft);color:var(--authority-blue)}
.authority-menu{position:relative}
.authority-menu__panel{position:absolute;top:calc(100% + 7px);right:0;min-width:260px;padding:10px;display:grid;grid-template-columns:1fr 1fr;gap:2px;background:#fff;border:1px solid var(--authority-line);border-radius:12px;box-shadow:0 18px 42px -20px rgba(23,24,27,.35)}
.authority-menu:not([open]) .authority-menu__panel{display:none}
.authority-menu__panel a{padding:8px 10px;border-radius:7px;color:var(--authority-muted);font-size:13px;text-decoration:none}
.authority-menu__panel a:hover,.authority-menu__panel a:focus-visible{background:var(--authority-soft);color:var(--authority-blue)}
.site-breadcrumb{max-width:1080px;margin:0 auto;padding:16px 24px 0;display:flex;flex-wrap:wrap;align-items:center;gap:8px;font-family:var(--sans,'Inter',system-ui,sans-serif);font-size:13px;color:var(--authority-faint)}
.site-breadcrumb a{color:var(--authority-muted);text-decoration:none}.site-breadcrumb a:hover{color:var(--authority-blue);text-decoration:underline}
.calculator-trust{max-width:760px;margin:34px 0 12px;padding:20px 22px;border:1px solid var(--authority-line);border-left:3px solid var(--authority-blue);border-radius:var(--authority-radius);background:var(--authority-surface);font-family:var(--sans,'Inter',system-ui,sans-serif)}
.calculator-trust h2{margin:0 0 8px;font-size:17px}.calculator-trust p{margin:0 0 10px;color:var(--authority-muted);font-size:14.5px}.calculator-trust__links{display:flex;flex-wrap:wrap;gap:8px 16px}.calculator-trust__links a{font-size:13.5px;font-weight:600;color:var(--authority-blue);text-decoration:none}.calculator-trust__links a:hover{text-decoration:underline}
.related-tools{max-width:760px;margin:22px 0 12px;font-family:var(--sans,'Inter',system-ui,sans-serif)}.related-tools h2{font-size:17px;margin:0 0 10px}.related-tools__links{display:flex;flex-wrap:wrap;gap:8px}.related-tools__links a{padding:7px 11px;border:1px solid var(--authority-line);border-radius:999px;background:#fff;color:var(--authority-muted);font-size:13px;font-weight:600;text-decoration:none}.related-tools__links a:hover{border-color:var(--authority-blue);color:var(--authority-blue)}
.guide-callout{max-width:760px;margin:22px 0;padding:16px 18px;border-radius:var(--authority-radius);background:var(--authority-soft);font-family:var(--sans,'Inter',system-ui,sans-serif);font-size:14.5px;color:#263b67}.guide-callout a{font-weight:700;color:var(--authority-blue)}
.authority-footer{margin-top:58px;border-top:1px solid var(--authority-line);background:var(--authority-surface);font-family:var(--sans,'Inter',system-ui,sans-serif)}
.authority-footer__inner{max-width:1080px;margin:0 auto;padding:38px 24px 32px;display:grid;grid-template-columns:1.7fr repeat(3,1fr);gap:26px 36px}
.authority-footer__brand a{display:flex;align-items:center;gap:9px;color:var(--authority-ink);font-weight:700;text-decoration:none}.authority-footer__brand p{max-width:30ch;margin:10px 0 0;color:var(--authority-muted);font-size:13.5px}
.authority-footer__group{display:flex;flex-direction:column;gap:7px}.authority-footer__group h2{margin:0 0 3px;color:var(--authority-ink);font-size:13px;text-transform:uppercase;letter-spacing:.08em}.authority-footer__group a{color:var(--authority-muted);font-size:13.5px;text-decoration:none}.authority-footer__group a:hover{color:var(--authority-blue)}
.authority-footer__note{grid-column:1/-1;margin:5px 0 0;padding-top:20px;border-top:1px solid var(--authority-line);color:var(--authority-faint);font-size:12px}
.authority-page{max-width:1080px;margin:0 auto;padding:28px 24px 64px;font-family:var(--sans,'Inter',system-ui,sans-serif);color:var(--authority-ink)}
.authority-page__hero{max-width:800px;padding:26px 0 34px}.authority-page__kicker{margin:0 0 10px;color:var(--authority-blue);font-size:13px;font-weight:700;text-transform:uppercase;letter-spacing:.13em}.authority-page h1{font-size:clamp(32px,5vw,48px);line-height:1.1;letter-spacing:-.03em;margin:0 0 16px}.authority-page__lead{max-width:68ch;margin:0;color:var(--authority-muted);font-size:18px;line-height:1.65}
.authority-article{max-width:780px}.authority-article h2{margin:42px 0 12px;font-size:25px;line-height:1.25;letter-spacing:-.018em}.authority-article h3{margin:28px 0 9px;font-size:18px}.authority-article p,.authority-article li{color:#2b2d33;line-height:1.72}.authority-article p{margin:0 0 15px}.authority-article ul,.authority-article ol{padding-left:23px}.authority-article li{margin:7px 0}.authority-article a{color:var(--authority-blue)}
.article-meta{display:flex;flex-wrap:wrap;gap:6px 18px;margin:18px 0 8px;padding:14px 0;border-top:1px solid var(--authority-line);border-bottom:1px solid var(--authority-line);color:var(--authority-muted);font-size:13.5px}.article-meta a{font-weight:700;color:var(--authority-ink)}
.formula{display:block;margin:14px 0;padding:13px 16px;overflow-x:auto;border:1px solid var(--authority-line);border-radius:9px;background:var(--authority-surface);font-family:var(--mono,'JetBrains Mono',monospace);font-size:15px;color:var(--authority-ink);white-space:nowrap}
.worked-example{margin:20px 0;padding:20px 22px;border:1px solid #cfdcf8;border-radius:var(--authority-radius);background:#f8faff}.worked-example h3{margin-top:0}.worked-example .formula{background:#fff}
.technical-diagram{margin:24px 0 30px;padding:16px;border:1px solid var(--authority-line);border-radius:var(--authority-radius);background:linear-gradient(160deg,#0e355e,#092544);box-shadow:inset 0 0 0 1px rgba(190,220,255,.16)}.technical-diagram svg{display:block;width:100%;height:auto;max-height:360px}.technical-diagram figcaption{margin-top:10px;color:#d4e6ff;font-size:13px}.technical-diagram .edge{fill:rgba(208,232,255,.06);stroke:#eaf3ff;stroke-width:2.2}.technical-diagram .dim{fill:none;stroke:#ffd57e;stroke-width:1.5}.technical-diagram .dash{fill:none;stroke:#8cbaf0;stroke-width:1.2;stroke-dasharray:7 6}.technical-diagram text{fill:#ffe6a8;font-family:var(--mono,'JetBrains Mono',monospace);font-size:15px}.technical-diagram .fill{fill:rgba(37,99,235,.55);stroke:#9fc7ff;stroke-width:1.5}
.content-grid,.learn-grid,.authority-cards{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}.content-card{display:flex;flex-direction:column;padding:22px;border:1px solid var(--authority-line);border-radius:var(--authority-radius);background:#fff;color:inherit;text-decoration:none}.content-card:hover{border-color:var(--authority-blue);box-shadow:0 14px 30px -24px rgba(37,99,235,.7);transform:translateY(-1px)}.content-card .eyebrow{color:var(--authority-blue);font-size:12px;font-weight:700;text-transform:uppercase;letter-spacing:.1em}.content-card h2,.content-card h3{margin:8px 0 8px;font-size:18px;line-height:1.3}.content-card p{margin:0;color:var(--authority-muted);font-size:14.5px}.content-card .card-link{margin-top:auto;padding-top:16px;color:var(--authority-blue);font-size:13px;font-weight:700}
.authority-band{max-width:1080px;margin:54px auto 0;padding:34px;border:1px solid var(--authority-line);border-radius:16px;background:var(--authority-surface)}.authority-band h2{margin:0 0 10px;font-size:25px}.authority-band p{max-width:72ch;color:var(--authority-muted)}.authority-band ul{columns:2;padding-left:22px}.authority-band a{font-weight:600;color:var(--authority-blue)}
.inline-cta{display:inline-flex;margin-top:5px;padding:10px 16px;border-radius:999px;background:var(--authority-blue);color:#fff!important;font-size:14px;font-weight:700;text-decoration:none}.inline-cta:hover{background:#1d4ed8}
.comparison-table{width:100%;border-collapse:collapse;margin:20px 0}.comparison-table th,.comparison-table td{padding:11px 12px;border:1px solid var(--authority-line);text-align:left;vertical-align:top}.comparison-table th{background:var(--authority-surface);font-size:13px}.comparison-table td{font-size:14px;color:#2b2d33}
@media(max-width:820px){.authority-nav{position:relative}.authority-nav__inner{align-items:flex-start;flex-direction:column;gap:8px}.authority-links{width:100%;margin:0;display:grid;grid-template-columns:1fr 1fr}.authority-links>a,.authority-menu>summary{text-align:center}.authority-menu__panel{position:static;grid-template-columns:1fr;margin:5px 0 8px;box-shadow:none}.authority-footer__inner{grid-template-columns:1fr 1fr}.authority-footer__brand{grid-column:1/-1}.content-grid,.learn-grid,.authority-cards{grid-template-columns:1fr 1fr}}
@media(max-width:560px){.authority-nav__inner{padding:9px 16px}.authority-brand{align-self:center}.authority-menu[open]>summary{background:var(--authority-soft);color:var(--authority-blue)}.site-breadcrumb{padding:13px 16px 0}.authority-footer__inner{grid-template-columns:1fr;padding:32px 20px}.authority-footer__brand,.authority-footer__note{grid-column:auto}.authority-page{padding:20px 18px 48px}.authority-page__hero{padding-top:18px}.content-grid,.learn-grid,.authority-cards{grid-template-columns:1fr}.authority-band{padding:24px 20px}.authority-band ul{columns:1}.comparison-table{display:block;overflow-x:auto}}
@media(prefers-reduced-motion:reduce){.content-card{transition:none}}