:root{--rl-navy:#081827;--rl-blue:#155a86;--rl-cyan:#2f7da8;--rl-ink:#102a43;--rl-muted:#617386;--rl-line:#e5ebf0;--rl-bg:#f7f9fb;--rl-white:#fff;--rl-gold:#f2b84b}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;color:var(--rl-ink);background:#fff;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",Arial,sans-serif;line-height:1.65}a{color:var(--rl-blue);text-decoration:none}a:hover{color:#075681}.rl-container{width:min(1180px,calc(100% - 36px));margin:auto}.rl-topbar{background:var(--rl-navy);color:#cbd7e1;font-size:12px}.rl-topbar .rl-container{height:36px;display:flex;align-items:center;justify-content:space-between}.rl-toplinks{display:flex;gap:16px}.rl-toplinks a{color:#d7e3eb}.rl-header{background:rgba(255,255,255,.98);border-bottom:1px solid #dbe3e9;box-shadow:0 4px 18px rgba(8,24,39,.07);position:sticky;top:0;z-index:50;backdrop-filter:blur(10px)}.rl-header-inner{min-height:82px;display:flex;align-items:center;gap:34px}.rl-logo img{display:block;width:258px;height:auto;max-height:64px}.rl-nav{margin-left:auto;display:flex;align-items:center;gap:4px}.rl-nav>ul{display:flex;align-items:center;list-style:none;margin:0;padding:0}.rl-nav li{position:relative}.rl-nav a{display:block;color:#183042;font-size:12.5px;font-weight:750;letter-spacing:.15px;padding:31px 14px;transition:color .18s ease,background .18s ease}.rl-nav a:hover,.rl-nav .current-menu-item>a,.rl-nav .current_page_item>a{color:var(--rl-blue)}.rl-nav .menu-item-has-children>a:after{content:"⌄";font-size:11px;margin-left:6px}.rl-nav .sub-menu{display:none;position:absolute;top:100%;left:0;background:#fff;min-width:225px;padding:8px 0;border:1px solid var(--rl-line);box-shadow:0 16px 35px rgba(16,42,67,.12);list-style:none}.rl-nav li:hover>.sub-menu{display:block}.rl-nav .sub-menu a{padding:10px 15px}.rl-subscribe{background:var(--rl-blue);color:#fff!important;border-radius:6px!important;padding:12px 18px!important;margin-left:10px;white-space:nowrap;box-shadow:0 5px 14px rgba(21,90,134,.18)}.rl-mobile-toggle{display:none;border:1px solid var(--rl-line);background:#fff;border-radius:7px;padding:8px 11px;font-size:20px}.rl-hero{position:relative;background:#071b2c center/cover no-repeat url("../images/hero-refinery.jpg");min-height:475px;color:#fff;display:flex;align-items:center}.rl-hero:before{content:"";position:absolute;inset:0;background:linear-gradient(90deg,rgba(2,17,30,.94) 0%,rgba(2,17,30,.72) 52%,rgba(2,17,30,.18) 100%)}.rl-hero .rl-container{position:relative;display:grid;grid-template-columns:minmax(0,1.15fr) 360px;gap:55px;align-items:center}.rl-hero h1{font-size:54px;line-height:1.08;margin:0 0 18px;letter-spacing:-1.5px}.rl-hero p{font-size:18px;color:#d7e4ed;max-width:670px;margin:0 0 28px}.rl-actions{display:flex;gap:12px;flex-wrap:wrap}.rl-btn{display:inline-flex;align-items:center;justify-content:center;min-height:46px;padding:0 20px;border-radius:6px;font-weight:800;font-size:13px;border:1px solid transparent}.rl-btn-primary{background:#1184d1;color:#fff}.rl-btn-primary:hover{background:#0a6fab;color:#fff}.rl-btn-dark{background:rgba(4,18,31,.8);border-color:#587081;color:#fff}.rl-popular{background:rgba(5,22,37,.88);border:1px solid rgba(143,190,215,.25);padding:24px;border-radius:6px}.rl-popular h3{margin:0 0 15px;font-size:16px}.rl-popular-item{display:flex;gap:12px;padding:10px 0;border-bottom:1px solid rgba(255,255,255,.09)}.rl-popular-item:last-child{border:0}.rl-icon{width:31px;height:31px;border:1px solid rgba(110,205,244,.5);border-radius:7px;display:grid;place-items:center;color:#75d1f3;flex:none}.rl-popular strong{display:block;font-size:12px}.rl-popular span{display:block;color:#b6c8d5;font-size:10px}.rl-trust{border-bottom:1px solid var(--rl-line);background:#fff}.rl-trust-grid{display:grid;grid-template-columns:repeat(5,1fr)}.rl-trust-item{padding:19px 10px;display:flex;gap:11px;align-items:center;border-right:1px solid #eef2f5}.rl-trust-item:last-child{border:0}.rl-trust-icon{font-size:23px}.rl-trust strong{font-size:12px;display:block}.rl-trust span{font-size:10px;color:var(--rl-muted)}.rl-main{padding:40px 0 60px;background:#fff}.rl-content-grid{display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:32px}.rl-section-head{display:flex;align-items:end;justify-content:space-between;margin-bottom:17px}.rl-section-head h2{font-size:21px;margin:0}.rl-section-head a{font-size:12px;font-weight:800}.rl-post-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}.rl-card{border:1px solid var(--rl-line);border-radius:7px;background:#fff;overflow:hidden;transition:.2s;box-shadow:0 3px 12px rgba(16,42,67,.03)}.rl-card:hover{transform:translateY(-2px);box-shadow:0 12px 30px rgba(16,42,67,.09)}.rl-thumb{display:block;aspect-ratio:16/9;background:#eaf1f5;overflow:hidden}.rl-thumb img{width:100%;height:100%;object-fit:cover;display:block}.rl-card-body{padding:14px}.rl-cat{font-size:10px;text-transform:uppercase;letter-spacing:.6px;font-weight:800;color:var(--rl-blue)}.rl-card h3{font-size:16px;line-height:1.3;margin:6px 0 8px}.rl-card p{font-size:12px;color:var(--rl-muted);margin:0 0 9px}.rl-meta{font-size:10px;color:#8795a2}.rl-guides{margin-top:30px}.rl-guide-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:12px}.rl-guide{border:1px solid var(--rl-line);padding:16px;border-radius:7px;min-height:105px}.rl-guide-icon{font-size:24px}.rl-guide h3{font-size:13px;margin:4px 0}.rl-guide p{font-size:10px;color:var(--rl-muted);margin:0}.rl-sidebar section,.rl-widget{border:1px solid var(--rl-line);border-radius:7px;padding:17px;margin-bottom:17px;background:#fff}.rl-widget-title{font-size:15px;margin:0 0 13px}.rl-search{display:flex}.rl-search input{width:100%;border:1px solid var(--rl-line);border-right:0;padding:10px 12px;border-radius:6px 0 0 6px}.rl-search button{width:45px;border:0;background:var(--rl-blue);color:#fff;border-radius:0 6px 6px 0}.rl-standard-list,.rl-tool-list{list-style:none;padding:0;margin:0}.rl-standard-list li,.rl-tool-list li{padding:7px 0;border-bottom:1px solid #eef2f5;font-size:12px}.rl-ad{background:#f2f4f6;border:1px dashed #d2d9df;min-height:90px;display:grid;place-items:center;text-align:center;color:#7c8995;font-size:12px;margin:15px 0}.rl-newsletter{background:var(--rl-navy);color:#fff!important}.rl-newsletter p{font-size:11px;color:#c9d7e0}.rl-newsletter input{width:100%;padding:11px;border:0;border-radius:5px;margin-bottom:9px}.rl-newsletter button{width:100%;padding:11px;border:0;border-radius:5px;background:#1184d1;color:#fff;font-weight:800}.rl-products{margin:40px 0}.rl-product-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:15px}.rl-product{border:1px solid var(--rl-line);padding:12px;border-radius:7px;text-align:center}.rl-product img{width:100%;height:155px;object-fit:contain}.rl-product h3{font-size:12px;margin:5px}.rl-price{font-weight:800;font-size:12px}.rl-affiliate-btn{display:block;background:#f1b83e;color:#1f2933;padding:8px;border-radius:4px;font-size:10px;font-weight:800;margin-top:8px}.rl-bottom-ad{margin:25px auto;max-width:970px}.rl-footer{background:var(--rl-navy);color:#c6d3dc;padding:45px 0 20px}.rl-footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:30px}.rl-footer h3{color:#fff;font-size:13px}.rl-footer p,.rl-footer li,.rl-footer a{font-size:11px;color:#b9c8d2}.rl-footer ul{list-style:none;padding:0;margin:0}.rl-footer li{margin:7px 0}.rl-footer-bottom{border-top:1px solid rgba(255,255,255,.1);margin-top:30px;padding-top:15px;text-align:center;font-size:10px}.rl-page-head{background:#f3f7fa;padding:45px 0;border-bottom:1px solid var(--rl-line)}.rl-page-head h1{margin:0;font-size:36px}.rl-breadcrumb{font-size:11px;color:var(--rl-muted);margin-bottom:8px}.rl-single{padding:45px 0}.rl-single-layout{max-width:880px;margin:auto}.rl-single h1{font-size:43px;line-height:1.15;margin:0 0 12px}.rl-single .rl-featured{margin:25px 0;border-radius:8px;overflow:hidden}.rl-single .rl-featured img{display:block;width:100%;height:auto}.rl-single-content{font-size:17px}.rl-single-content h2,.rl-single-content h3{color:var(--rl-ink);margin-top:32px}.rl-single-content table{width:100%;border-collapse:collapse}.rl-single-content th,.rl-single-content td{border:1px solid var(--rl-line);padding:9px;text-align:left}.rl-single-content img{max-width:100%;height:auto}.rl-share{padding:15px 0;border-top:1px solid var(--rl-line);margin-top:30px}.rl-ebook-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}.rl-ebook-card{border:1px solid var(--rl-line);border-radius:8px;overflow:hidden}.rl-ebook-card img{width:100%;aspect-ratio:3/4;object-fit:cover}.rl-ebook-body{padding:16px}.rl-form{display:grid;gap:12px}.rl-form input,.rl-form textarea{width:100%;border:1px solid var(--rl-line);border-radius:6px;padding:11px}.rl-form textarea{min-height:150px}.screen-reader-text{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}@media(max-width:980px){.rl-nav{display:none}.rl-mobile-toggle{display:block;margin-left:auto}.rl-hero .rl-container{grid-template-columns:1fr}.rl-popular{display:none}.rl-hero h1{font-size:43px}.rl-trust-grid{grid-template-columns:repeat(3,1fr)}.rl-content-grid{grid-template-columns:1fr}.rl-sidebar{display:grid;grid-template-columns:repeat(2,1fr);gap:16px}.rl-sidebar section{margin:0}.rl-footer-grid{grid-template-columns:repeat(2,1fr)}}@media(max-width:980px){.rl-nav.rl-mobile-open{display:block;position:absolute;left:18px;right:18px;top:100%;background:#fff;border:1px solid var(--rl-line);box-shadow:0 16px 30px rgba(16,42,67,.12)}.rl-nav.rl-mobile-open>ul{display:block}.rl-nav.rl-mobile-open a{padding:12px 16px}.rl-nav.rl-mobile-open .sub-menu{position:static;display:block;box-shadow:none;border:0;padding-left:12px}}.rl-footer .rl-logo img{filter:brightness(0) invert(1);max-width:230px}@media(max-width:650px){.rl-topbar{display:none}.rl-logo img{width:205px}.rl-header-inner{min-height:68px}.rl-hero{min-height:520px}.rl-hero h1{font-size:35px}.rl-hero p{font-size:15px}.rl-trust-grid,.rl-post-grid,.rl-guide-grid,.rl-product-grid,.rl-ebook-grid,.rl-sidebar,.rl-footer-grid{grid-template-columns:1fr}.rl-trust-item{border-right:0;border-bottom:1px solid #eef2f5}.rl-main{padding-top:28px}.rl-single h1{font-size:32px}.rl-single-content{font-size:16px}}

/* RefiningLab professional header refinement */
.rl-header:after{content:"";position:absolute;left:0;right:0;bottom:-1px;height:2px;background:linear-gradient(90deg,transparent 0%,var(--rl-blue) 25%,var(--rl-cyan) 50%,var(--rl-blue) 75%,transparent 100%);opacity:.7}
.rl-nav .sub-menu{border-top:2px solid var(--rl-blue);border-radius:0 0 7px 7px}
.rl-nav .sub-menu a:hover{background:#f2f6f9}
.rl-topbar{background:#081827}
.rl-toplinks a:hover{color:#fff}