:root{--navy:#102f43;--gold:#e7c66f;--line:#dce4e6;--ink:#203b49}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:100px}body{margin:0;color:var(--ink);background:#fff;font:17px/1.75 system-ui,-apple-system,sans-serif}a{color:#155c70;text-underline-offset:4px}img{max-width:100%;height:auto}button,input,select,textarea{font:inherit}button,a,input,select,textarea{touch-action:manipulation}input,select,textarea{font-size:16px;padding:12px;border:1px solid #aebec6;border-radius:8px;width:100%;min-width:0;background:#fff;color:var(--ink)}textarea{resize:vertical}button,.button{display:inline-flex;align-items:center;justify-content:center;min-height:46px;padding:11px 20px;border:0;border-radius:8px;background:var(--navy);color:white;font-weight:700;text-decoration:none;cursor:pointer}a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible{outline:3px solid #be861d;outline-offset:3px}[hidden]{display:none!important}.topbar{background:var(--navy);color:white;text-align:center;padding:7px 16px;font-size:13px}.topbar a{color:white}.header{background:white;border-bottom:1px solid var(--line);padding:14px max(20px,calc((100vw - 1200px)/2));display:flex;gap:24px;align-items:center}.logo{display:flex;align-items:center;gap:12px;text-decoration:none;color:var(--navy);font-weight:800;font-size:16px;line-height:1.4}.logo img{width:65px;height:70px;object-fit:contain}.nav{display:flex;flex-wrap:wrap;gap:10px 20px;margin-left:auto}.nav a{font-size:14px;font-weight:650;text-decoration:none}.nav details summary{display:none}.nav details nav{display:flex;gap:16px}.header .button{background:#bd2636;font-size:14px}.wrap{max-width:1200px;margin:auto;padding:28px 24px 80px}.breadcrumbs{font-size:13px;color:#59717d;display:flex;gap:8px;flex-wrap:wrap;margin:0 0 28px}.hero{display:grid;grid-template-columns:1.25fr 1fr;gap:36px;align-items:center;margin-bottom:30px}.hero h1,h1{font-size:clamp(30px,4vw,45px);line-height:1.25;letter-spacing:-.025em}.eyebrow{font-size:12px;font-weight:800;letter-spacing:.13em;color:#97712c;text-transform:uppercase}.hero p{font-size:18px}.hero-images{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;background:#f4f6f2;padding:22px;border-radius:20px}.hero-images img{height:220px;width:100%;object-fit:contain}.hero-images figcaption{font-size:12px;text-align:center}.hero-images figure{margin:0}.actions{display:flex;gap:10px;flex-wrap:wrap;margin:24px 0}.actions .button:first-child{background:#f2ce6d;color:var(--navy)}.note{font-size:14px;color:#536c77}.toc{display:flex;gap:12px 22px;flex-wrap:wrap;background:#eff4f4;padding:20px;border-radius:12px;font-size:14px}.body{max-width:940px}.body h2{font-size:28px;line-height:1.4;margin:32px 0 16px}.body section{scroll-margin-top:95px}.body p,.body li{line-height:1.9}.body .depth{max-width:100%}.body table{border-collapse:collapse;width:100%;font-size:15px}.body th,.body td{padding:13px;border-bottom:1px solid var(--line);text-align:left;vertical-align:top}.scroll{overflow:auto}.body .sources{overflow-wrap:anywhere;font-size:14px}.shop{margin:36px 0;padding:28px;border:1px solid var(--line);border-radius:18px;background:#f4f7f7}.products{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.product{min-width:0;background:white;border:1px solid var(--line);border-radius:12px;padding:20px;display:flex;flex-direction:column;gap:10px}.product img{height:200px;width:100%;object-fit:contain}.product h3{font-size:19px;line-height:1.4;margin:8px 0}.product p,.product details{font-size:14px;margin:0}.product label,.request label{display:grid;gap:6px;font-size:14px;font-weight:650}.product .choose{display:flex;align-items:center;gap:10px;padding:12px;background:#edf4f1;border-radius:8px;margin-top:auto;font-size:15px;cursor:pointer}.choose input{width:22px;height:22px;margin:0;flex-shrink:0}.fields{display:grid;grid-template-columns:1fr 85px;gap:8px}.request{display:grid;gap:16px;margin-top:28px;max-width:850px}.request h3{margin-bottom:0}.output{margin:24px 0;scroll-margin-top:30px}.output textarea{line-height:1.7}.notice{background:#fff7df;padding:20px;border-left:4px solid var(--gold);margin:24px 0}.store{background:var(--navy);color:white;border-radius:16px;padding:28px;margin-top:36px}.store a{color:#f6d983}.store h2{margin-top:0}.grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px;margin:25px 0}.tile{padding:22px;border:1px solid var(--line);border-radius:12px;display:block;text-decoration:none;color:var(--ink)}.tile h2,.tile h3{font-size:21px;line-height:1.4;margin:8px 0}.tile p{font-size:14px}.tile:hover{border-color:#718f9c;background:#f7f9f7}.foot{background:#eef3f4;padding:30px max(24px,calc((100vw - 1152px)/2));font-size:14px}.search{max-width:600px}.faq{border-top:1px solid var(--line);padding:16px 0}.faq summary{cursor:pointer;font-weight:700}.skip{position:absolute;left:-10000px}.skip:focus{left:20px;top:20px;background:#fff;padding:12px;z-index:99}@media(max-width:850px){.hero{grid-template-columns:1fr}.products,.grid{grid-template-columns:repeat(2,minmax(0,1fr))}.header{gap:12px;flex-wrap:wrap}.nav{order:3;width:100%}.hero-images img{height:180px}}@media(max-width:560px){body{font-size:16px}.wrap{padding:20px 16px 45px}.header{padding:12px 16px}.logo{font-size:13px}.logo img{width:45px;height:50px}.header>.button{margin-left:auto;padding:10px 12px;font-size:12px}.nav{gap:14px}.nav a{font-size:13px}.hero{gap:18px}.hero h1,h1{font-size:31px}.hero p{font-size:16px}.hero-images{padding:15px 8px;gap:8px}.hero-images img{height:145px}.hero-images figcaption{font-size:11px}.products,.grid{grid-template-columns:1fr}.shop{padding:16px 12px}.product{padding:18px}.product img{height:190px}.actions .button{flex:1 1 140px}.store{padding:22px}.body h2{font-size:25px}.body table{min-width:520px}.foot{padding:24px 16px}.topbar{font-size:11px}}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}@media print{.header,.topbar,.nav,.shop,.toc,.actions,.foot{display:none}.wrap{padding:0}.hero{display:block}.hero-images{display:none}.body{max-width:none}.depth{break-inside:auto}.body h2{break-after:avoid}body{font-size:11pt}.body table{min-width:0;font-size:10pt}.scroll{overflow:visible}.store{background:white;color:black;border:1px solid #ccc}.store a{color:black}}

.depth.depth{margin:44px 0;padding:clamp(20px,4vw,40px);background:#f5f8f7;border:1px solid #d9e3df;border-radius:20px;line-height:1.85;color:#203a43;min-width:0;overflow-wrap:anywhere}.depth.depth h2{font-size:clamp(25px,3vw,36px);line-height:1.3;margin:12px 0 22px}.depth.depth h3{font-size:23px;line-height:1.4;margin:32px 0 16px}.depth.depth p{margin:16px 0}.kicker{font-size:12px!important;letter-spacing:.14em;font-weight:800;color:#6d572d}.scroll{width:100%;overflow-x:auto;margin:24px 0;border-radius:10px}.scroll:focus-visible{outline:3px solid #966c22;outline-offset:4px}.depth.depth table{width:100%;border-collapse:collapse;font-size:16px;min-width:540px;background:white}.depth.depth caption{text-align:left;padding:12px 0;font-weight:700}.depth.depth th,.depth.depth td{padding:15px;text-align:left;border-bottom:1px solid #dce4e5;vertical-align:top}.depth.depth thead{background:#143843;color:white}.depth.depth tbody th{font-weight:600}.depth.depth small{display:block;margin-top:8px;font-weight:400;color:#526573}.depth.depth a{color:#135b64;text-underline-offset:4px}.depth.depth figure{margin:30px 0}.depth.depth figure img{width:100%;height:auto;border-radius:12px;display:block}.depth.depth figcaption{font-size:14px;line-height:1.6;color:#526573;margin-top:12px}.steps{padding-left:26px}.steps li{padding:8px 0 8px 5px}.note{border-left:4px solid #b38739;padding:14px 18px;background:#fff9e9}.math{display:grid;gap:8px;background:#143843;color:white;padding:22px;border-radius:12px}.math strong{font-size:clamp(18px,3vw,25px)}.depth.depth blockquote{margin:24px 0;border-left:4px solid #507d75;padding:18px;background:white}.depth.depth .action{display:inline-block;background:#143843;color:white;padding:13px 20px;border-radius:8px;font-weight:700;text-decoration:none}@media(max-width:600px){.depth.depth{padding:18px 14px;border-radius:12px;font-size:17px}.depth.depth h3{font-size:21px}.depth.depth td,.depth.depth th{padding:12px}.depth.depth figure{margin:24px -4px}.depth.depth .action{display:block;text-align:center}.math{padding:18px 14px}}@media print{.depth.depth{background:white;border:0;padding:0}.depth.depth figure{max-height:450px;break-inside:avoid}.depth.depth figure img{max-height:400px;object-fit:contain}.scroll{overflow:visible}.depth.depth table{min-width:0;font-size:11px}.depth.depth tr{break-inside:avoid}.action{display:none!important}}

/* R2: long-form reading, product identification, measurement and request. */
.offer-panel{background:#f6f0dc;border:1px solid #ddc98e;border-radius:16px;padding:26px;color:#173e48;min-width:0}.offer-panel.offer-top{max-width:920px;margin:0 auto 34px}.offer-panel h2{font-size:clamp(23px,3vw,30px);line-height:1.4;margin:5px 0 14px}.offer-panel p{line-height:1.8;margin:12px 0}.offer-kicker{font-size:11px;font-weight:800;letter-spacing:.12em;color:#785616}.offer-panel .offer-small{font-size:13px;line-height:1.75;color:#4b6264}.offer-actions{display:flex;flex-wrap:wrap;gap:12px;align-items:center;margin:20px 0 12px}.offer-actions .offer-zalo{background:#1255a5;color:#fff}.offer-actions .offer-call{background:#fff;color:#173e48;border:1px solid #899b9d}.offer-quote{font-size:14px;font-weight:700}.offer-full{margin:38px 0 25px}.body .offer-full h2{margin:6px 0 14px}.offer-terms{font-size:14px;background:#fffaf0;padding:15px 18px;border-radius:10px}.offer-inline{border-left:4px solid #b48e37;background:#f1f4ee;padding:20px 24px;margin:28px 0}.offer-inline strong{font-size:18px;line-height:1.6}.offer-inline p{font-size:15px}.offer-inline a{font-weight:700}.offer-hub{margin:26px 0}.offer-actions a:focus-visible{outline:3px solid #1255a5;outline-offset:4px}@media(max-width:950px){.offer-panel.offer-top{margin-left:20px;margin-right:20px}}@media(max-width:560px){.offer-panel{padding:20px 16px;border-radius:12px}.offer-panel.offer-top{margin-left:16px;margin-right:16px}.offer-panel h2{font-size:23px}.offer-actions{display:grid;grid-template-columns:1fr;width:100%}.offer-actions .button{width:100%;text-align:center;font-size:15px}.offer-inline{padding:18px 16px}.offer-terms{padding:13px}.offer-full .offer-small{font-size:12px}}@media print{.offer-top,.offer-inline,.offer-actions{display:none!important}.offer-panel{background:white;border-color:#ccc}}
body{background:#fcfcf9;color:#243c44}
.wrap{width:100%}.breadcrumbs{max-width:1200px;margin:auto;padding-bottom:12px}
.hero{padding-top:26px;padding-bottom:28px;gap:42px;margin-bottom:0;grid-template-columns:1.3fr 1fr}
.hero h1{font-size:clamp(29px,3.1vw,44px);line-height:1.28;margin:14px 0 22px;max-width:720px}
.hero p{font-size:18px;line-height:1.8}.hero .reading{font-size:13px;color:#5e7375}
.hero-images{background:#edf1e9;padding:24px 12px;border:1px solid #e0e6db}
.hero-images img{height:170px;max-width:150px;object-fit:contain;margin:auto;display:block}
.hero-images figcaption{font-size:12px;line-height:1.5;margin-top:14px}
.button.secondary{background:transparent;color:#123847;border:1px solid #a3b3b5}
.article-contact{max-width:1152px;margin:0 auto 30px;padding:14px 20px;border-top:1px solid #dde6df;border-bottom:1px solid #dde6df;display:flex;gap:12px 28px;flex-wrap:wrap;font-size:13px}
.article-contact span{font-weight:700}.article-contact a{font-weight:600}
.body{max-width:920px;padding-top:10px;padding-bottom:25px}.body h2{font-size:clamp(25px,3vw,32px);line-height:1.4;margin-top:48px}
.body h3{font-size:22px;line-height:1.5;margin:30px 0 12px}.body p{line-height:1.93;margin:16px 0}
.toc{gap:9px 20px;padding:18px 22px;background:#eef2ee;border:1px solid #dce4df;border-radius:12px}
.case{background:#f5efde;border:1px solid #e8dcc0;border-radius:14px;padding:22px 28px;margin:25px 0}
.case h3{margin-top:10px}.case p:last-child{font-size:13px;color:#63706b;line-height:1.7;margin-bottom:0}
.editorial-products{display:grid;gap:18px;margin:26px 0}.editorial-product{margin:0;display:grid;grid-template-columns:150px 1fr;gap:25px;align-items:center;padding:24px;background:white;border:1px solid #dde5df;border-radius:14px}
.editorial-product img{width:150px;height:180px;object-fit:contain}.editorial-product h3{margin:5px 0 12px;font-size:20px}
.editorial-product p{font-size:15px;line-height:1.75;margin:10px 0}.editorial-product a{font-size:14px;font-weight:700}
.measurement-figure{margin:26px 0}.measurement-figure img{display:block;width:100%;height:auto;border-radius:14px;border:1px solid #dce5dc}
figcaption{font-size:13px;line-height:1.7;color:#52696d;margin-top:9px}.body caption{text-align:left;font-weight:700;font-size:15px;padding:10px 0}
.body table{background:#fff}.body thead{background:#183e48;color:#fff}.body td,.body th{padding:14px 16px;line-height:1.7}
.body tbody tr:nth-child(even){background:#f0f4ef}.scroll{border-radius:10px;margin:22px 0}
.measure{border:1px solid #b9ccc7;border-radius:14px;background:#eaf1ed;padding:26px;margin:26px 0}
.measure h3{margin-top:0}.measure-fields{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-bottom:20px}
.measure-fields label{display:grid;gap:7px;font-size:14px;font-weight:650}.measure-fields label:first-child{grid-column:1/-1}
#measure-result{font-weight:700;white-space:pre-line}#use-area{background:#1b605b}
.geo{padding:17px 20px;background:#f1f4ee;border-radius:10px;font-size:14px}.geo summary{font-weight:700;cursor:pointer}
.faq{padding:19px 0}.faq summary{font-size:17px;line-height:1.6}.sources{padding:20px;background:#f0f3ee;border-radius:10px;margin:25px 0}
.shop.wrap{max-width:1152px;margin:35px auto 55px;background:#eef3ef}.shop .products{gap:16px}.product>img{max-width:160px;height:180px;align-self:center}
.product h3{font-size:18px}.product{gap:12px}.fields{grid-template-columns:1fr}.fields input[readonly]{background:#eef1ed}
.fields label:nth-child(2){max-width:180px}.product:target{outline:3px solid #bb9a42;outline-offset:3px;scroll-margin-top:20px}
.foot .article-contact{padding:16px 0;margin-top:25px;margin-bottom:0}.foot h2{font-size:22px}
@media(max-width:850px){.hero{grid-template-columns:1fr}.hero-images{max-width:650px}.hero-images img{height:145px}.article-contact{margin-left:20px;margin-right:20px}.measure{padding:20px}.shop.wrap{width:calc(100% - 32px)}}
@media(max-width:560px){.hero{padding-top:10px;gap:18px}.hero h1{font-size:29px;line-height:1.32}.hero p{font-size:16px}.hero-images{padding:16px 9px;gap:8px}.hero-images img{height:110px;max-width:100%}.hero-images figcaption{font-size:11px}.article-contact{margin:0 16px 22px;padding:13px 0;gap:9px 18px;font-size:12px}.article-contact span{width:100%}.body{padding-top:0}.body h2{margin-top:36px;font-size:25px}.body h3{font-size:21px}.case{padding:20px 18px}.editorial-product{grid-template-columns:90px minmax(0,1fr);gap:14px;padding:18px 14px;align-items:start}.editorial-product img{width:90px;height:130px}.editorial-product h3{font-size:17px;overflow-wrap:anywhere}.editorial-product p{font-size:14px}.editorial-product a{font-size:13px}.editorial-product .eyebrow{font-size:10px}.measure{padding:18px 15px}.measure-fields{grid-template-columns:1fr}.measure-fields label:first-child{grid-column:auto}.measure button{width:100%}.body table{min-width:540px}.body p{line-height:1.9}.faq summary{font-size:16px}.shop.wrap{width:calc(100% - 24px)}.foot .article-contact{margin-left:0;margin-right:0}}
@media print{.article-contact,.measure,.shop,.toc{display:none!important}.hero{display:block}.body{max-width:none}.case,.editorial-product{break-inside:avoid}.editorial-product{grid-template-columns:90px 1fr}.editorial-product img{height:120px}.body h2{font-size:20px;margin-top:24px}.body h3{font-size:16px}.body p{line-height:1.55}.measurement-figure{break-inside:avoid}.body table{min-width:0}.body td,.body th{padding:7px;font-size:10px}.sources{font-size:10px}}