:root{--navy:#071d41;--blue:#1351b4;--green:#168821;--yellow:#ffcd07;--paper:#f4f7fb;--line:#d5dce5;--ink:#1f2d3d;--muted:#52667a;--white:#fff}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:126px}body{margin:0;font:16px/1.65 Inter,ui-sans-serif,system-ui,-apple-system,"Segoe UI",sans-serif;color:var(--ink);background:#fff}a{color:inherit}.wrap{max-width:1160px;margin:auto;padding:0 22px}.site-header{position:sticky;top:0;z-index:100;box-shadow:0 2px 10px rgba(7,29,65,.12)}.govbar{background:var(--navy);color:#fff;font-size:.8rem}.govbar .wrap{height:34px;display:flex;align-items:center;justify-content:space-between}.govbar a{text-decoration:none}.nav{background:#fff;border-bottom:1px solid var(--line)}.nav-inner{min-height:72px;display:flex;align-items:center;justify-content:space-between;gap:22px}.brand{display:flex;align-items:center;gap:9px;text-decoration:none;font-weight:900;color:var(--navy);font-size:1.23rem;letter-spacing:-.03em;white-space:nowrap}.brand-mark{width:32px;height:32px;background:var(--blue);color:#fff;display:grid;place-items:center;border-radius:4px}.brand em{font-style:normal;color:var(--blue)}.navlinks{display:flex;align-items:center;gap:17px}.navlinks a{text-decoration:none;font-size:.86rem;font-weight:750;color:var(--navy);padding:9px 4px;border-bottom:3px solid transparent;white-space:nowrap}.navlinks a:hover,.navlinks a.active{color:var(--blue);border-color:var(--blue)}.navlinks a.learn{background:var(--blue);color:#fff;padding:9px 12px;border:0;border-radius:4px}.breadcrumb{background:#f1f3f5;border-bottom:1px solid var(--line);font-size:.84rem;color:var(--muted);padding:9px 0}.breadcrumb a{color:var(--blue)}.hero{background:#eef4fb;border-bottom:5px solid var(--yellow);padding:58px 0}.hero-grid{display:grid;grid-template-columns:minmax(0,1fr) 360px;gap:48px;align-items:center}.eyebrow{display:block;text-transform:uppercase;letter-spacing:.1em;font-size:.77rem;font-weight:900;color:var(--blue)}h1{font-size:clamp(2.5rem,5vw,4.4rem);line-height:1.03;letter-spacing:-.052em;color:var(--navy);margin:12px 0 18px}.lead{font-size:1.13rem;color:#38526d;max-width:760px}.hero-panel{background:#fff;border:1px solid #cbd5e0;border-top:5px solid var(--blue);padding:24px;box-shadow:0 5px 18px rgba(7,29,65,.10)}.hero-panel h2{font-size:1.05rem;margin:0 0 12px;color:var(--navy)}.hero-panel a{display:flex;justify-content:space-between;gap:12px;padding:10px 0;border-bottom:1px solid #e2e7ec;text-decoration:none;color:var(--blue);font-weight:750}.hero-panel a:last-child{border:0}.section{padding:70px 0}.section.alt{background:var(--paper)}.section.dark{background:var(--navy);color:#fff}.section-head{max-width:790px;margin-bottom:32px}.section-head h2{font-size:clamp(2rem,4vw,3rem);line-height:1.1;color:var(--navy);margin:8px 0 12px;letter-spacing:-.035em}.dark .section-head h2{color:#fff}.section-head p{color:var(--muted)}.dark .section-head p{color:#c7d5e5}.grid{display:grid;gap:18px}.grid-2{grid-template-columns:repeat(2,1fr)}.grid-3{grid-template-columns:repeat(3,1fr)}.grid-4{grid-template-columns:repeat(4,1fr)}.card{background:#fff;border:1px solid var(--line);padding:25px;text-decoration:none;transition:.2s}.card:hover{border-color:#92a6bb;box-shadow:0 5px 16px rgba(7,29,65,.1)}.card .num{display:inline-grid;place-items:center;width:36px;height:36px;background:#e7f1ff;color:var(--blue);font-weight:900;margin-bottom:18px}.card h3{color:var(--navy);margin:0 0 8px}.card p{margin:0;color:var(--muted)}.card .more{display:block;color:var(--blue);font-weight:800;margin-top:17px}.callout{border-left:6px solid var(--yellow);background:#fffdf1;padding:23px 26px;margin:28px 0;font-weight:700}.article-layout{display:grid;grid-template-columns:250px minmax(0,1fr);gap:42px}.toc{position:sticky;top:128px;align-self:start;border:1px solid var(--line);background:#fff}.toc strong{display:block;padding:14px 16px;background:var(--navy);color:#fff}.toc a{display:block;padding:10px 15px;border-bottom:1px solid #e5e9ee;color:var(--blue);text-decoration:none;font-size:.9rem;font-weight:700}.content h2{font-size:2rem;color:var(--navy);margin:48px 0 12px}.content h2:first-child{margin-top:0}.content h3{color:var(--navy);margin-top:30px}.content p,.content li{color:#40566d}.compare{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin:24px 0}.box{border:1px solid var(--line);padding:23px;background:#fff}.box.blue{background:#eef4fb;border-top:5px solid var(--blue)}.box.green{background:#eef9f0;border-top:5px solid var(--green)}.steps{counter-reset:s}.step{counter-increment:s;position:relative;padding:0 0 28px 62px;border-left:2px solid #cbd6e2;margin-left:20px}.step:before{content:counter(s);position:absolute;left:-22px;top:0;width:42px;height:42px;border-radius:50%;background:var(--blue);color:#fff;display:grid;place-items:center;font-weight:900}.step h3{margin:0 0 6px}.table-wrap{overflow:auto;border:1px solid var(--line)}table{border-collapse:collapse;width:100%;min-width:680px}th,td{text-align:left;padding:16px;border-bottom:1px solid var(--line)}th{background:var(--navy);color:#fff}.search{width:100%;padding:16px 18px;border:2px solid var(--line);font-size:1rem;margin-bottom:22px}.terms{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}.term{border:1px solid var(--line);padding:19px}.term h3{margin:0 0 6px;color:var(--navy)}.term p{margin:0;color:var(--muted);font-size:.92rem}.btn{display:inline-flex;align-items:center;justify-content:center;text-decoration:none;border-radius:4px;padding:12px 17px;font-weight:850}.btn-primary{background:var(--blue);color:#fff}.teacher-feature{display:grid;grid-template-columns:420px minmax(0,1fr);gap:48px;align-items:center}.teacher-feature img{width:100%;max-height:650px;object-fit:cover;object-position:center 18%;border:1px solid var(--line)}.quote{font-size:clamp(1.35rem,2.6vw,2.05rem);line-height:1.38;color:var(--navy);font-weight:700;margin:15px 0 22px}.quote:before{content:'“';color:var(--blue);font-size:3.5rem;line-height:0;vertical-align:-.25em;margin-right:7px}.signature{color:var(--blue);font-weight:900}.recommend-path{margin-top:50px}.recommend{display:grid;grid-template-columns:90px 1fr;gap:22px;padding:28px 0;border-top:1px solid var(--line)}.recommend-number{width:70px;height:70px;border-radius:50%;border:2px solid var(--blue);display:grid;place-items:center;color:var(--blue);font-size:1.4rem;font-weight:900}.recommend h2{margin:0 0 8px;color:var(--navy)}.recommend p{color:var(--muted)}footer{background:#06162f;color:#c8d5e5;border-top:5px solid var(--yellow);padding:36px 0}.footer-grid{display:flex;justify-content:space-between;gap:25px;align-items:center}.footer-grid a{color:#fff;text-decoration:none}.footer-brand{color:#fff;font-weight:900}
@media(max-width:980px){.nav-inner{align-items:flex-start;flex-direction:column;padding:12px 22px}.navlinks{width:100%;overflow-x:auto}.hero-grid,.teacher-feature{grid-template-columns:1fr}.teacher-feature img{max-width:540px}.grid-4{grid-template-columns:repeat(2,1fr)}.grid-3,.terms{grid-template-columns:repeat(2,1fr)}.article-layout{grid-template-columns:1fr}.toc{position:static}.site-header{position:sticky}}
@media(max-width:620px){.govbar span{display:none}.hero{padding:40px 0}.grid-2,.grid-3,.grid-4,.compare,.terms{grid-template-columns:1fr}.recommend{grid-template-columns:1fr}.footer-grid{align-items:flex-start;flex-direction:column}.teacher-feature{gap:26px}.teacher-feature img{max-height:520px}}

.contact-widget{position:fixed;left:18px;bottom:16px;z-index:200;width:min(360px,calc(100vw - 28px));font-family:Inter,ui-sans-serif,system-ui,-apple-system,"Segoe UI",sans-serif}.contact-trigger{display:flex;align-items:center;gap:5px;border:0;background:transparent;padding:0;cursor:pointer;filter:drop-shadow(0 8px 16px rgba(7,29,65,.22))}.contact-trigger img{width:94px;height:94px;object-fit:contain;object-position:center bottom;transition:transform .2s}.contact-trigger:hover img{transform:translateY(-3px)}.contact-trigger span{position:relative;background:#fff;color:var(--navy);border:2px solid var(--blue);border-radius:14px;padding:11px 14px;font-size:.92rem;font-weight:850;line-height:1.2;box-shadow:0 5px 18px rgba(7,29,65,.14)}.contact-trigger span:before{content:"";position:absolute;left:-9px;bottom:18px;width:14px;height:14px;background:#fff;border-left:2px solid var(--blue);border-bottom:2px solid var(--blue);transform:rotate(45deg)}.contact-card{display:none;position:absolute;left:8px;bottom:106px;width:340px;max-width:calc(100vw - 44px);background:#fff;border:1px solid var(--line);border-top:5px solid var(--blue);padding:23px;border-radius:8px;box-shadow:0 18px 48px rgba(7,29,65,.22)}.contact-card.is-open{display:block;animation:contact-in .18s ease-out}.contact-close{position:absolute;right:10px;top:8px;border:0;background:transparent;color:var(--muted);font-size:1.7rem;line-height:1;cursor:pointer}.contact-kicker{display:block;color:var(--blue);font-size:.7rem;font-weight:900;text-transform:uppercase;letter-spacing:.08em}.contact-card h2{color:var(--navy);font-size:1.35rem;line-height:1.2;margin:5px 28px 17px 0}.contact-card label{display:block;color:var(--navy);font-size:.82rem;font-weight:800;margin:10px 0 4px}.contact-card input,.contact-card textarea{width:100%;border:1px solid #aebccc;border-radius:4px;padding:10px 11px;color:var(--ink);font:inherit;font-size:.92rem;background:#fff}.contact-card input:focus,.contact-card textarea:focus{outline:3px solid rgba(19,81,180,.18);border-color:var(--blue)}.contact-card textarea{resize:vertical;min-height:92px}.field-error,.contact-status{display:block;font-size:.76rem;line-height:1.35}.field-error,.contact-status.error{color:#b42318}.contact-submit{width:100%;border:0;border-radius:4px;background:var(--blue);color:#fff;padding:11px 14px;margin-top:14px;font-weight:850;font-size:.92rem;cursor:pointer}.contact-submit:hover{background:#0c4195}.contact-submit:disabled{opacity:.65;cursor:wait}.contact-consent{color:var(--muted);font-size:.7rem;line-height:1.35;margin:8px 0 0}.contact-status{margin:8px 0 0;font-weight:750}.contact-status.success{color:var(--green)}@keyframes contact-in{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}
@media(max-width:620px){.contact-widget{left:8px;bottom:8px;width:calc(100vw - 16px)}.contact-trigger img{width:78px;height:78px}.contact-trigger span{font-size:.82rem;padding:9px 11px}.contact-card{left:0;bottom:92px;width:100%;max-width:none;max-height:calc(100vh - 118px);overflow:auto}}

/* SEO knowledge hub */
.hero.compact{padding:48px 0}.hero.compact h1{max-width:900px}.answer{max-width:900px;font-size:1.22rem;line-height:1.7}.content{min-width:0}.content>p{max-width:790px}.content a{color:var(--blue);font-weight:700}.plain-steps{padding-left:1.35rem;max-width:800px}.plain-steps li{padding:7px 0 7px 8px}.example,.note,.warning{padding:22px 24px;margin:25px 0;max-width:850px;border-left:6px solid var(--blue);background:#eef4fb}.example strong,.note strong,.warning strong{display:block;font-size:.76rem;letter-spacing:.08em;color:var(--navy);margin-bottom:7px}.example p,.note p,.warning p{margin:0}.note{background:#eef9f0;border-color:var(--green)}.warning{background:#fff8dc;border-color:#d99b00}.sources{margin-top:56px;padding-top:28px;border-top:1px solid var(--line)}.sources h2{font-size:1.35rem;margin:0 0 12px}.sources li{margin:8px 0}.soft-cta{margin-top:42px;padding:32px;background:var(--paper);border:1px solid var(--line);border-top:5px solid var(--blue)}.soft-cta h2{margin:6px 0 8px;font-size:1.8rem}.soft-cta p{margin:0 0 18px}.home-intro{display:grid;grid-template-columns:minmax(0,1fr) 350px;gap:42px;align-items:start;margin-bottom:64px}.home-intro h2,.section-inline h2{margin-top:0}.quick-links{border:1px solid var(--line);border-top:5px solid var(--blue);background:#fff}.quick-links strong,.quick-links a{display:block;padding:13px 17px}.quick-links strong{background:var(--navy);color:#fff}.quick-links a{border-bottom:1px solid var(--line);text-decoration:none;color:var(--blue);font-weight:750}.section-inline{margin-top:60px}.topic-grid{margin-top:24px}.learning-path{max-width:820px}.learning-path a{display:grid;grid-template-columns:54px 1fr;gap:18px;align-items:center;padding:20px 0;border-bottom:1px solid var(--line);text-decoration:none}.learning-path b{width:48px;height:48px;display:grid;place-items:center;border-radius:50%;background:var(--blue);color:#fff}.learning-path strong,.learning-path small{display:block}.learning-path strong{font-size:1.12rem;color:var(--navy)}.learning-path small{color:var(--muted);font-weight:500}.btn-secondary{border:1px solid var(--blue);color:var(--blue);margin-left:8px}.menu-button{display:none;border:1px solid var(--line);background:#fff;color:var(--navy);font-weight:800;padding:9px 12px}.navlinks a:focus-visible,.btn:focus-visible,.menu-button:focus-visible{outline:3px solid var(--yellow);outline-offset:2px}
@media(max-width:980px){.menu-button{display:block;position:absolute;right:22px;top:51px}.nav-inner{position:relative}.navlinks{display:none;flex-direction:column;align-items:stretch;overflow:visible;gap:0}.navlinks.is-open{display:flex}.navlinks a{padding:11px 4px}.home-intro{grid-template-columns:1fr}.answer{font-size:1.08rem}}
@media(max-width:620px){.hero.compact{padding:34px 0}.soft-cta{padding:24px}.btn-secondary{margin:10px 0 0}.content h2{font-size:1.65rem}.home-intro{gap:26px}}

/* Keep button labels legible when buttons appear inside article content. */
.content a.btn-primary,.content a.btn-primary:visited{color:#fff}
.content a.btn-primary:hover{color:#fff;background:#0c4195}