:root{--muted:#a7b6cd;--border:rgba(148,163,184,.19)}
body{overflow-x:hidden}a{color:#7ee9ff;text-underline-offset:4px}a:hover{color:#fff}button,input,textarea,select{font:inherit}p{line-height:1.75}main,.footer{position:relative}h1,h2,h3{letter-spacing:-.025em}section[id],h2[id]{scroll-margin-top:110px}.header{width:min(1180px,94%);gap:20px}.logo small{display:block;color:var(--muted);font-size:11px;font-weight:500;letter-spacing:.015em}.header nav{gap:7px}.header nav a{color:#c5d2e5}.header nav a.btn{color:#041525}.container{width:min(1180px,92%)}.hero{display:grid!important;grid-template-columns:1.45fr 1fr;padding:68px 0 48px!important;gap:56px!important}.hero-text{min-width:0}.hero h1{font-size:clamp(36px,4.4vw,58px);line-height:1.12;margin:14px 0 24px}.hero p{max-width:65ch}.hero-visual{display:flex;align-items:center;justify-content:center;min-height:400px}.formula-boxes{display:grid;gap:15px;width:80%}.formula{background:linear-gradient(130deg,rgba(34,211,238,.07),rgba(96,165,250,.025));border:1px solid var(--border);border-radius:14px;padding:15px 22px;box-shadow:0 14px 32px rgba(0,0,0,.15);text-align:center;animation:floatY 7s ease-in-out infinite}.formula:nth-child(even){margin-left:36px;animation-delay:1s}.formula .main{display:block;font-size:25px}.formula .sub{display:block;margin-top:5px;font-weight:400;letter-spacing:0}.hero-bullets strong{color:#f5f8fd}.hero-bullets li{font-size:13px;color:var(--muted);padding:14px}.eyebrow{color:#6ae5f6;font-size:11px;font-weight:800;letter-spacing:.14em;display:block;line-height:1.65}.hero-cta{flex-wrap:wrap;margin:26px 0}.section{padding:48px 0}.section-heading{display:flex;justify-content:space-between;align-items:end;gap:36px;margin-bottom:24px}.section-heading h2{margin-bottom:0;margin-top:8px}.section-heading p{max-width:440px;color:var(--muted);margin:0}.service-cards{grid-template-columns:repeat(3,minmax(0,1fr))}.service-cards .card{display:flex;flex-direction:column;padding:26px;background:linear-gradient(140deg,rgba(255,255,255,.04),rgba(255,255,255,.015))}.card h3{font-size:20px;line-height:1.4}.card h3 a{color:var(--text);text-decoration:none}.card h3 a:hover{color:var(--accent)}.number-label{color:#65a9e9;font-weight:800;font-size:13px;margin-bottom:15px;display:block}.card-price{margin-top:auto;border-top:1px solid var(--border);padding-top:18px;margin-bottom:16px;font-weight:750}.card-price small{font-weight:400;color:var(--muted);display:block}.text-link{font-size:14px;font-weight:650;line-height:1.6}.approach-cards{grid-template-columns:repeat(3,minmax(0,1fr))}.approach-cards .card{padding:26px}.price-wrap{border:1px solid var(--border);border-radius:16px;overflow:hidden;background:rgba(255,255,255,.025)}.pricetable{border-collapse:collapse;width:100%}.pricetable th,.pricetable td{text-align:left;padding:19px 22px;border-bottom:1px solid var(--border)}.pricetable th{color:#fff;background:rgba(96,165,250,.08);font-size:14px}.pricetable td:nth-child(2){font-weight:750;white-space:nowrap}.pricetable td:nth-child(3){white-space:nowrap;color:var(--muted)}.pricetable tbody tr:last-child td{border-bottom:0}.pricetable a{color:var(--text);text-decoration:none}.small-text{color:var(--muted);font-size:13px}.article-grid{grid-template-columns:repeat(3,minmax(0,1fr))}.article-card{padding:0;overflow:hidden}.article-card>a{display:block}.article-card img{width:100%;height:auto;aspect-ratio:3/2;object-fit:cover;display:block}.card-body{padding:24px}.card-body h3{margin-top:11px}.card-body p{font-size:14px}.faq{max-width:900px}summary{cursor:pointer;font-weight:650;line-height:1.55}details p{color:var(--muted);margin-bottom:4px}.contact-grid{display:grid;grid-template-columns:1.3fr 1fr;gap:50px}.contact-list{list-style:none;padding:0}.contact-list li{margin:15px 0;font-size:19px}.contact-grid .card{padding:28px}.contact-grid li{margin-bottom:12px;color:var(--muted)}.footer{grid-template-columns:1fr 1fr;align-items:start;padding:35px 0}.footer-links{justify-content:flex-end;font-size:13px;flex-wrap:wrap}.copy{grid-column:1/-1;text-align:left}.breadcrumb{display:flex;flex-wrap:wrap;gap:8px 12px;font-size:12px;padding:25px 0 0;color:var(--muted)}.breadcrumb a{color:#a7c5e5}.page-hero{padding:40px 0 30px}.page-hero h1{font-size:clamp(32px,4vw,48px);line-height:1.2;max-width:950px;margin:12px 0 20px}.lead{font-size:18px;color:var(--muted);max-width:850px}.reading-layout{display:grid;grid-template-columns:minmax(0,800px) 300px;gap:52px;align-items:start}.prose{font-size:17px;line-height:1.85;min-width:0}.prose>p:first-child{margin-top:0}.prose h2{font-size:28px;line-height:1.35;margin:42px 0 16px}.prose h3{font-size:22px;margin:26px 0 12px}.prose p{margin:0 0 20px}.prose ul,.prose ol{padding-left:25px;margin:20px 0}.prose li{margin-bottom:8px}.prose strong{color:#f6f9ff}.prose img{max-width:100%;height:auto;border-radius:14px;display:block;margin:28px auto}.prose table{width:100%;border-collapse:collapse;display:block;overflow:auto}.prose td,.prose th{padding:14px;border:1px solid var(--border)}.prose blockquote{margin:25px 0;border-left:3px solid var(--accent);padding:16px 22px;background:rgba(34,211,238,.04)}.prose a{text-decoration:underline;color:#7ee9ff}.reading-sidebar{position:sticky;top:110px;display:grid;gap:22px}.reading-sidebar .card{padding:24px}.contact-box{background:linear-gradient(140deg,rgba(34,211,238,.09),rgba(96,165,250,.06));border:1px solid rgba(34,211,238,.22);border-radius:18px;padding:28px}.contact-box h3{font-size:24px;line-height:1.25;margin:12px 0}.contact-box p{color:var(--muted)}.contact-box .btn{font-size:19px;display:inline-block}.price-card>strong{display:block;font-size:25px;margin-top:12px}.service-banner{border:1px solid rgba(34,211,238,.25);padding:24px;border-radius:16px;margin:36px 0;background:linear-gradient(100deg,rgba(34,211,238,.07),rgba(96,165,250,.04));font-size:15px}.service-banner h3{margin:8px 0 18px;font-size:23px}.service-line{display:flex;justify-content:space-between;align-items:center;gap:24px;border-top:1px solid var(--border);padding:15px 0}.service-line small{display:block;color:var(--muted)}.service-line strong{white-space:nowrap;font-size:14px}.service-banner .btn{margin-top:12px;color:#00111a;text-decoration:none}.article-meta{font-size:13px;color:var(--muted);margin:20px 0}.article-cover{width:100%;max-height:520px;height:auto;object-fit:contain;aspect-ratio:3/2;border-radius:20px;margin:15px 0 20px}.toc{background:rgba(255,255,255,.025);border:1px solid var(--border);border-radius:16px;padding:24px 28px;margin-bottom:35px}.toc h2{font-size:19px;margin:0 0 10px}.toc ol{font-size:14px;margin:10px 0 0}.editorial-note{font-size:13px;color:var(--muted);border-top:1px solid var(--border);padding-top:22px}.search-form{display:flex;gap:12px;max-width:700px;margin:25px 0}.search-form input{margin:0}.category-chips{display:flex;flex-wrap:wrap;gap:9px;margin:26px 0 0}.category-chips a{padding:8px 13px;border:1px solid var(--border);border-radius:30px;font-size:13px;text-decoration:none;color:var(--muted)}.category-chips a.active{color:#031424;background:var(--accent);border-color:var(--accent)}.empty-state{padding:60px 20px;text-align:center;border:1px dashed var(--border);border-radius:20px}.pagination{display:flex;gap:8px;margin:30px 0}.pagination a{padding:8px 16px;border:1px solid var(--border);border-radius:10px;text-decoration:none}.pagination [aria-current]{background:var(--accent);color:#00111a}.notice{padding:18px;background:#184457;border-radius:10px;margin-bottom:20px}.mobile-call{display:none}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}.skip-link{position:absolute;top:-100px;left:20px;z-index:100;background:#fff;color:#000;padding:12px}.skip-link:focus{top:12px}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid var(--accent);outline-offset:4px}
@keyframes floatY{0%,100%{transform:translateY(0)}50%{transform:translateY(-6px)}}
@media(max-width:1000px){.hero{grid-template-columns:1.35fr 1fr;gap:25px!important}.hero-bullets{grid-template-columns:1fr}.hero-bullets li{padding:8px 12px}.service-cards{grid-template-columns:repeat(2,minmax(0,1fr))}.reading-layout{grid-template-columns:minmax(0,1fr) 270px;gap:28px}.article-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.hero-visual{height:auto}.hero-cta .btn{font-size:14px}.hero h1{font-size:43px}.header nav{gap:0}.header nav a{padding:8px;font-size:13px}}
@media(max-width:760px){body{padding-bottom:66px}.header{position:relative;flex-wrap:wrap;padding:16px 0;gap:14px}.header nav{width:100%;justify-content:space-between;gap:0}.header nav a{font-size:12px;padding:8px 5px}.header nav .btn.small{padding:8px}.hero{grid-template-columns:1fr;padding:32px 0 20px!important;gap:20px!important}.hero h1{font-size:38px}.hero-visual{min-height:0;height:auto}.formula-boxes{grid-template-columns:1fr 1fr;width:100%;gap:10px}.formula{padding:12px 8px;animation:none}.formula .main{font-size:19px}.formula .sub{font-size:11px}.formula:nth-child(even){margin-left:0}.formula:last-child{grid-column:1/-1}.hero-bullets{grid-template-columns:repeat(3,minmax(0,1fr))}.hero-bullets li{font-size:11px}.hero-bullets strong{font-size:12px}.hero-cta{margin:20px 0}.section{padding:34px 0}.section-heading{display:block}.section-heading p{margin-top:15px}.section-heading>a{display:inline-block;margin-top:12px}.service-cards,.approach-cards,.article-grid,.contact-grid{grid-template-columns:1fr}.service-cards .card{padding:23px}.contact-grid{gap:20px}.pricetable thead{display:none}.pricetable tr{display:block;border-bottom:1px solid var(--border);padding:8px}.pricetable td{display:flex;justify-content:space-between;gap:18px;padding:10px 12px;border-bottom:0;font-size:14px}.pricetable td:before{content:attr(data-th);color:var(--muted);font-weight:400;min-width:70px}.pricetable td:first-child{text-align:right}.pricetable td:nth-child(2){font-size:16px}.reading-layout{grid-template-columns:1fr;gap:25px}.reading-sidebar{position:static}.page-hero{padding-top:28px}.page-hero h1{font-size:32px}.lead{font-size:17px}.prose{font-size:16px}.prose h2{font-size:24px}.toc{padding:22px}.service-banner{padding:20px}.service-line{flex-direction:column;align-items:flex-start;gap:7px}.article-cover{border-radius:14px}.search-form{gap:8px}.search-form .btn{padding:10px 12px;font-size:14px}.footer{grid-template-columns:1fr;gap:20px;justify-items:start;text-align:left}.footer-links{justify-content:flex-start}.copy{text-align:left}.mobile-call{display:block;position:fixed;bottom:10px;left:4%;width:92%;text-align:center;padding:13px;background:linear-gradient(90deg,#22d3ee,#60a5fa);border:1px solid #9edaff;color:#00111a;font-weight:750;border-radius:12px;box-shadow:0 8px 30px #0008;z-index:20;text-decoration:none}.contact-box{padding:23px}}
@media(prefers-reduced-motion:reduce){html,body{scroll-behavior:auto}.formula{animation:none}}

/* v3: softer navy palette and quiet mathematical background */
:root{--bg:#1b2b43;--panel:#24364f;--card:#273b55;--text:#f0f5fc;--muted:#c1cfe0;--border:rgba(196,217,240,.20);--grid:rgba(185,211,240,.045)}
html,body{background:linear-gradient(145deg,#1b2b43 0%,#263c56 52%,#1e314b 100%);color:var(--text)}
.header{background:rgba(27,43,67,.92)}
.bg-grid{background-size:64px 64px}
.bg-grid:before,.bg-grid:after{position:absolute;color:rgba(196,227,247,.09);font-family:Georgia,serif;font-style:italic;white-space:pre;line-height:3.4;pointer-events:none;font-size:clamp(20px,2.5vw,38px)}
.bg-grid:before{content:'a² + b² = c²\A   y = ax + b\A πr²\A   (a + b)²';left:2%;top:15%;transform:rotate(-9deg)}
.bg-grid:after{content:'s = v · t\A   x₁ + x₂\A sin²α + cos²α = 1\A   Δ = b² − 4ac';right:1%;top:24%;transform:rotate(8deg)}
.card,.price,.formula,.toc,.table-scroll{background:rgba(40,61,87,.92)}
.prose{background:rgba(29,47,70,.97);padding:30px;border:1px solid var(--border);border-radius:20px}
.prose strong{color:#fff}.prose a{color:#92eaff}.reading-sidebar .card{background:#293e57}
.contact-box,.service-banner{background:linear-gradient(135deg,#28495f,#293e59)}
@media(max-width:760px){.prose{padding:20px 16px;border-radius:16px}.bg-grid:before,.bg-grid:after{font-size:21px;color:rgba(196,227,247,.06)}.bg-grid:after{right:-70px}}