:root{color-scheme:dark;--bg:#070b12;--panel:#101824;--ink:#f3f6fb;--muted:#aebccc;--blue:#75c7ff;--gold:#ffc065;--line:#263443;--max:1180px}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:95px}body{margin:0;background:var(--bg);color:var(--ink);font:17px/1.65 system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}a{color:var(--blue);text-underline-offset:4px}a:hover{color:#fff}button,a,summary{-webkit-tap-highlight-color:transparent}:focus-visible{outline:3px solid var(--gold);outline-offset:5px}img{max-width:100%;height:auto}h1,h2,h3{line-height:1.12;letter-spacing:-.035em;color:var(--ink)}h1{font-size:clamp(2.35rem,5vw,4.5rem);margin:18px 0 24px;max-width:960px}h2{font-size:clamp(1.8rem,3vw,2.9rem);margin:0 0 22px}h3{font-size:1.35rem;margin:0 0 13px}p{margin:0 0 20px}strong{color:#f1f5fb}.muted,.trial-note{color:var(--muted)}.skip{position:absolute;top:-90px;left:20px;z-index:30;background:#fff;color:#000;padding:12px}.skip:focus{top:12px}.site-nav{max-width:var(--max);margin:auto;min-height:90px;padding:18px 28px;display:flex;align-items:center;justify-content:space-between;gap:28px;border-bottom:1px solid var(--line)}.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:#fff;font-size:1.35rem;font-weight:760;white-space:nowrap;letter-spacing:-.03em}.brand img{border-radius:12px}.flash{color:var(--blue)}.site-nav nav{display:flex;gap:25px;align-items:center}.site-nav nav a{color:#c4cfda;font-size:.87rem;text-decoration:none}.button{display:inline-flex;align-items:center;justify-content:center;gap:16px;border:1px solid #385269;border-radius:10px;background:#102134;color:#fff;padding:13px 20px;line-height:1.35;font-weight:700;text-decoration:none;transition:background .15s,transform .15s}.button:hover{background:#1d364d;transform:translateY(-2px)}.button.primary{background:var(--blue);color:#06111d;border-color:var(--blue);box-shadow:0 8px 35px #1b7ec026}.button.primary:hover{background:#a7dfff}.button.small{font-size:.85rem;padding:11px 15px}.eyebrow{text-transform:uppercase;font:700 .74rem/1.4 system-ui;letter-spacing:.17em;color:var(--blue);margin-bottom:18px}.lead{font-size:clamp(1.1rem,2vw,1.28rem);line-height:1.65;color:#bdcbd9;max-width:730px}.hero{max-width:var(--max);margin:auto;padding:80px 28px 55px;display:grid;grid-template-columns:1.15fr .85fr;gap:65px;align-items:center}.hero h1{font-size:clamp(2.5rem,4.5vw,4.1rem)}.hero h1 em{font-style:normal;color:var(--blue)}.hero-actions{display:flex;gap:12px;flex-wrap:wrap;margin:28px 0 18px}.trial-note{font-size:.88rem;margin:16px 0;max-width:590px}.signal{display:inline-flex;align-items:center;gap:9px}.signal:before{content:"";width:6px;height:6px;border-radius:50%;background:var(--blue);box-shadow:0 0 12px #75c7ff}.hero-visual{position:relative;padding:22px;background:linear-gradient(145deg,#14273b,#090f18 70%);border:1px solid #31475c;border-radius:24px}.visual-top{display:flex;justify-content:space-between;font-size:.72rem;letter-spacing:.1em;color:#93aec9;margin-bottom:20px}.hero-visual figure{margin:0;display:flex;flex-direction:column;align-items:center}.hero-visual img{width:252px;border:1px solid #304050;border-radius:16px;box-shadow:0 25px 70px #0008}.hero-visual figcaption{font-size:.76rem;color:var(--muted);margin:18px 0 0;text-align:center}.strip{border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:20px 28px;max-width:1124px;margin:0 auto;display:flex;justify-content:space-between;gap:15px;flex-wrap:wrap;color:#b7c6d7;font-size:.9rem}.strip span:before{content:"+";color:var(--blue);margin-right:8px}.section{max-width:var(--max);padding:75px 28px;margin:auto}.section-head{max-width:760px;margin-bottom:35px}.section-head p{color:var(--muted)}.cards{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.card{position:relative;padding:29px;background:var(--panel);border:1px solid var(--line);border-radius:16px}.card p{color:var(--muted);font-size:.96rem;margin:0}.card .number{font:500 .75rem ui-monospace,monospace;color:var(--blue);display:block;margin-bottom:28px}.link-card{text-decoration:none;transition:border-color .18s,background .18s}.link-card:hover{border-color:#6082a3;background:#142031}.arrow{float:right;color:var(--blue);margin-left:10px}.split{display:grid;grid-template-columns:1fr 1fr;gap:45px;align-items:start}.practice-demo{background:#0e1927;border:1px solid #314357;border-radius:18px;padding:28px}.transmission{margin:20px 0;padding-left:15px;border-left:2px solid var(--blue)}.transmission.student{border-color:#79d9aa}.transmission span{color:var(--blue);font:700 .7rem system-ui;letter-spacing:.13em}.transmission.student span{color:#79d9aa}.transmission p{margin:7px 0}.note{padding:19px 22px;border:1px solid #3c4652;border-left:3px solid var(--gold);border-radius:8px;color:#c6d1dd;background:#111a24}.note p:last-child{margin:0}.practice-demo small{color:var(--muted)}.text-link{display:inline-block;margin-top:20px;font-weight:650}.faq{border-top:1px solid var(--line)}details{border-bottom:1px solid var(--line);padding:22px 0}summary{cursor:pointer;font-size:1.05rem;font-weight:650;color:#edf2f8}details p{margin:18px 0 0;color:var(--muted);max-width:850px}.banner{max-width:1124px;margin:35px auto 70px;padding:45px;background:linear-gradient(110deg,#172d43,#0e1824);border:1px solid #36516b;border-radius:20px}.banner h2{max-width:720px}.site-footer{max-width:var(--max);margin:auto;padding:45px 28px 60px;border-top:1px solid var(--line);display:grid;grid-template-columns:1fr 1fr;gap:60px;font-size:.88rem;color:var(--muted)}.site-footer .brand{margin-bottom:17px}.site-footer nav{display:grid;grid-template-columns:1fr 1fr;gap:12px}.site-footer nav a{color:#bdcbd9;text-decoration:none}.guide-wrap{max-width:1040px;margin:auto;padding:28px}.breadcrumb{display:flex;gap:12px;flex-wrap:wrap;color:#869aad;font-size:.81rem;margin:15px 0 50px}.guide-hero{padding-bottom:45px;border-bottom:1px solid var(--line)}.guide-hero h1{font-size:clamp(2.25rem,4.5vw,3.7rem);max-width:900px}.guide-body{max-width:920px;padding:48px 0 10px}.guide-body h2{font-size:clamp(1.7rem,3vw,2.15rem);margin:55px 0 22px}.guide-body h2:first-child{margin-top:0}.guide-body p,.guide-body li{color:#bdcbd9}.guide-body li{margin:10px 0}.guide-body .cards{grid-template-columns:repeat(2,minmax(0,1fr));margin:25px 0}.guide-body .section{padding:40px 0}.guide-body .section h2{margin-top:0}.sources{padding:30px 0 45px;border-top:1px solid var(--line);font-size:.87rem;color:var(--muted)}.sources h2{font-size:1.25rem}.sources p{max-width:900px}.example{padding:26px;margin:28px 0;background:#101e2c;border:1px solid #30475c;border-radius:12px}.example h3{font-size:1.2rem}.example p:last-child{margin-bottom:0}.formula{font:600 1.05rem/1.7 ui-monospace,monospace;color:var(--blue)!important;overflow-wrap:anywhere}.table-wrap{overflow:auto;border:1px solid var(--line);border-radius:12px;margin:25px 0}table{border-collapse:collapse;width:100%;font-size:.95rem;min-width:520px}th,td{padding:17px 20px;text-align:left;border-bottom:1px solid var(--line);vertical-align:top}th{color:#d8e7f4;background:#132334}td{color:var(--muted)}.contact-links{display:flex;gap:15px;flex-wrap:wrap;margin:25px 0}.contact-links a{display:inline-flex;gap:10px;align-items:center}.contact-links svg{width:22px;height:22px;fill:none;stroke:currentColor;stroke-width:1.7}.toc{padding:22px;background:#101925;border:1px solid var(--line);border-radius:12px}.toc a{display:inline-block;margin:5px 15px 5px 0}.two{grid-template-columns:repeat(2,minmax(0,1fr))}
@media(max-width:950px){.site-nav{gap:16px}.site-nav nav{gap:16px}.hero{gap:30px;padding-top:55px}.cards{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:700px){.site-nav{flex-wrap:wrap;padding:16px 20px;gap:14px;min-height:auto}.site-nav nav{order:3;width:100%;overflow:auto;white-space:nowrap;gap:23px;padding:5px 0}.site-nav .brand{font-size:1.15rem}.site-nav .brand img{width:34px;height:34px}.site-nav .small{margin-left:auto;font-size:.8rem}.hero{display:block;padding:42px 20px}.hero h1{font-size:2.8rem}.hero-visual{margin-top:38px;padding:18px;max-width:460px}.hero-visual img{width:230px}.section{padding:50px 20px}.cards,.guide-body .cards,.split,.site-footer{grid-template-columns:1fr}.card{padding:24px}.strip{margin:0 20px;padding:20px 0;font-size:.8rem;justify-content:flex-start;gap:12px 23px}.banner{margin:20px 20px 45px;padding:28px}.site-footer{padding:35px 20px;gap:20px}.guide-wrap{padding:20px}.breadcrumb{margin-bottom:35px}.guide-hero h1{font-size:2.35rem}.guide-body{padding-top:35px}.guide-body h2{margin-top:40px}.hero-actions .button{flex:1 1 170px}.trial-note{font-size:.81rem}.table-wrap{max-width:100%}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important}}
/* Keep every navigation destination visible on narrow phones. */
@media(max-width:700px){.site-nav nav{gap:10px 16px;flex-wrap:wrap;white-space:normal;overflow:visible}}
/* Short desktop windows should expose the study task and trial CTA early. */
@media(min-width:701px) and (max-height:800px){.hero{align-items:start;padding-top:45px}.hero-visual img{width:210px}}

/* Public guides: deliberate tablet/desktop composition, not a stretched phone page. */
@media (min-width: 768px) {
  :root { --max: 1280px; }
  .site-nav { flex-wrap: wrap; gap: 16px 24px; }
  .site-nav nav { flex-wrap: wrap; gap: 12px 20px; }
  .site-nav > .button { flex-shrink: 0; }
  .guide-wrap { max-width: var(--max); padding: 32px 40px; }
  .breadcrumb { margin-bottom: 32px; }
  .guide-hero { padding: 32px; border: 1px solid var(--line); border-radius: 20px; background: linear-gradient(130deg, #122337, var(--bg) 80%); }
  .guide-hero h1 { font-size: clamp(2.4rem, 3.6vw, 3.6rem); }
  .guide-body { max-width: none; padding-top: 40px; }
  .guide-body > p, .guide-body > ul, .guide-body > ol { max-width: 82ch; }
  .guide-body .cards { gap: 22px; }
  .guide-body .card { padding: 28px; }
  .guide-body .table-wrap { width: 100%; }
  .guide-body .split > * { min-width: 0; }
  .site-footer { gap: 48px; }
}
@media (min-width: 1100px) {
  .guide-hero { display: grid; grid-template-columns: minmax(0, 1fr) 280px; column-gap: 44px; align-items: start; }
  .guide-hero > .eyebrow, .guide-hero > h1, .guide-hero > .lead { grid-column: 1; }
  .guide-hero > .eyebrow { grid-row: 1; }
  .guide-hero > h1 { grid-row: 2; margin-top: 0; }
  .guide-hero > .lead { grid-row: 3; margin-bottom: 0; }
  .guide-hero > .button, .guide-hero > .hero-actions { grid-column: 2; grid-row: 2; align-self: center; }
  .guide-hero > .trial-note { grid-column: 2; grid-row: 3; padding-top: 16px; margin-top: 0; border-top: 1px solid var(--line); }
  .guide-body .cards:not(.two):has(> :last-child:nth-child(3)) { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}