:root{--color-primary:#1769e0;--color-primary-hover:#0d52b8;--color-text:#172033;--color-text-light:#667085;--color-background:#fff;--color-surface:#f6f8fb;--color-border:#e4e8ef;--color-success:#16835a;--color-warning:#b65d00;--radius:12px;--shadow:0 8px 28px rgba(23,32,51,.07);--container:1180px;--header-height:68px}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--color-background);color:var(--color-text);font:16px/1.65 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Arial,sans-serif}a{color:var(--color-primary);text-decoration-thickness:.08em;text-underline-offset:.18em}a:hover{color:var(--color-primary-hover)}img{height:auto;max-width:100%}button,input,textarea,select{font:inherit}button{cursor:pointer}.container{width:min(calc(100% - 32px),var(--container));margin-inline:auto}.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:fixed;z-index:1000;top:8px;left:8px;transform:translateY(-150%);background:var(--color-text);color:#fff;padding:10px 14px;border-radius:6px}.skip-link:focus{transform:none}:focus-visible{outline:3px solid #8cbcff;outline-offset:3px}.site-header{position:sticky;z-index:50;top:0;background:rgba(255,255,255,.96);border-bottom:1px solid var(--color-border);backdrop-filter:blur(10px)}.header-inner{height:var(--header-height);display:flex;align-items:center;gap:20px}.site-branding{margin-right:auto}.text-logo{color:var(--color-text);font-size:24px;font-weight:800;letter-spacing:-.04em;text-decoration:none}.custom-logo{display:block;max-height:42px;width:auto}.primary-nav{display:none;position:absolute;left:0;right:0;top:100%;background:#fff;border-bottom:1px solid var(--color-border);padding:12px 16px}.primary-nav.is-open{display:block}.menu,.primary-nav ul{list-style:none;margin:0;padding:0}.primary-nav a{display:block;padding:10px 8px;color:var(--color-text);font-weight:600;text-decoration:none}.menu-toggle,.search-toggle{border:0;background:transparent;padding:8px;color:var(--color-text)}.menu-toggle span:not(.sr-only){display:block;width:22px;height:2px;margin:4px;background:currentColor}.search-toggle svg{display:block;width:23px;height:23px;fill:none;stroke:currentColor;stroke-width:2}.header-search{padding:14px 0;background:var(--color-surface);border-top:1px solid var(--color-border)}.search-form{display:flex;width:100%;gap:8px}.search-form label{flex:1}.search-form input{width:100%;min-height:48px;border:1px solid #cbd2dc;border-radius:9px;padding:10px 14px;background:#fff;color:var(--color-text)}.search-form button{border:0;border-radius:9px;padding:10px 18px;background:var(--color-primary);color:#fff;font-weight:700}.hero{padding:58px 0;background:linear-gradient(180deg,#f4f8ff 0,#fff 100%)}.hero-inner{max-width:800px;text-align:center}.hero h1{margin:.15em 0;font-size:clamp(2.1rem,7vw,3.8rem);line-height:1.1;letter-spacing:-.045em}.hero p:not(.eyebrow){color:var(--color-text-light);font-size:1.1rem}.hero .search-form{margin:28px auto 0;max-width:700px;padding:7px;background:#fff;border:1px solid var(--color-border);border-radius:13px;box-shadow:var(--shadow)}.eyebrow{margin:0;color:var(--color-primary);font-size:.8rem;font-weight:800;letter-spacing:.12em;text-transform:uppercase}.section{padding-top:54px;padding-bottom:54px}.section>h2,.section-heading h2{margin:0 0 24px;font-size:clamp(1.65rem,4vw,2.2rem);line-height:1.2;letter-spacing:-.025em}.category-grid,.topic-grid{display:grid;gap:16px}.category-card{display:block;padding:24px;border:1px solid var(--color-border);border-radius:var(--radius);color:var(--color-text);text-decoration:none;transition:border-color .15s,box-shadow .15s}.category-card:hover{border-color:#a9c8f3;box-shadow:var(--shadow);color:var(--color-text)}.category-card h3{font-size:1.25rem;margin:16px 0 6px}.category-card p{margin:0;color:var(--color-text-light)}.card-icon{display:grid;width:42px;height:42px;place-items:center;border-radius:10px;background:#e8f1ff;color:var(--color-primary);font-weight:800}.card-link{display:inline-block;margin-top:18px;color:var(--color-primary);font-weight:700}.surface-section{background:var(--color-surface);border-block:1px solid var(--color-border)}.section-heading{display:flex;align-items:end;justify-content:space-between;gap:16px;margin-bottom:24px}.section-heading h2{margin:4px 0 0}.topic-group{padding:22px;background:#fff;border:1px solid var(--color-border);border-radius:var(--radius)}.topic-group h3{margin:0 0 14px;font-size:1.15rem}.topic-group h3 a{color:inherit}.guide-list,.link-list,.footer-links{list-style:none;padding:0;margin:0}.guide-list li{display:flex;align-items:center;justify-content:space-between;gap:12px;border-top:1px solid var(--color-border)}.guide-list li:first-child{border-top:0}.guide-list a{display:block;padding:11px 0;color:var(--color-text);text-decoration:none}.guide-list a:hover{color:var(--color-primary)}.guide-list span{color:var(--color-text-light)}.muted{color:var(--color-text-light)}.breadcrumbs{padding:20px 0;color:var(--color-text-light);font-size:.86rem}.breadcrumbs ol{display:flex;flex-wrap:wrap;gap:6px;list-style:none;margin:0;padding:0}.breadcrumbs li:not(:last-child)::after{content:"/";margin-left:6px;color:#a2aaba}.breadcrumbs a{color:inherit}.archive-header{max-width:780px;padding:32px 0 46px}.archive-header h1,.entry-header h1{margin:8px 0 12px;font-size:clamp(2rem,6vw,3.2rem);line-height:1.12;letter-spacing:-.04em}.archive-header .search-form{margin-top:24px}.term-description,.entry-summary{color:var(--color-text-light);font-size:1.08rem}.result-list{max-width:850px}.result-item{display:flex;justify-content:space-between;gap:24px;padding:26px 0;border-top:1px solid var(--color-border)}.result-item h2{margin:5px 0 7px;font-size:1.25rem}.result-item h2 a{color:var(--color-text);text-decoration:none}.result-item p{margin:0;color:var(--color-text-light)}.entry-category{font-size:.84rem;font-weight:700;text-decoration:none}.read-more{align-self:center;font-size:1.5rem;text-decoration:none}.nav-links{display:flex;gap:8px;margin:30px 0}.page-numbers{padding:7px 12px;border:1px solid var(--color-border);border-radius:7px;text-decoration:none}.page-numbers.current{background:var(--color-primary);color:#fff;border-color:var(--color-primary)}.single-wrap{padding-bottom:70px}.article-layout{display:grid}.article{min-width:0;max-width:780px;margin-inline:auto}.entry-header{margin-bottom:28px}.entry-summary{font-size:1.15rem}.entry-meta{color:var(--color-text-light);font-size:.86rem}.entry-content{font-size:17px;line-height:1.76}.entry-content h2,.entry-content h3{scroll-margin-top:calc(var(--header-height) + 22px);line-height:1.28;letter-spacing:-.02em}.entry-content h2{margin:2.1em 0 .65em;font-size:1.75rem}.entry-content h3{margin:1.7em 0 .55em;font-size:1.35rem}.entry-content p,.entry-content ul,.entry-content ol{margin:0 0 1.25em}.entry-content li+li{margin-top:.35em}.entry-content blockquote{margin:1.5em 0;padding:2px 0 2px 20px;border-left:4px solid var(--color-primary);color:var(--color-text-light)}.entry-content table{width:100%;border-collapse:collapse;display:block;overflow-x:auto}.entry-content th,.entry-content td{padding:10px 12px;border:1px solid var(--color-border);text-align:left}.entry-content code,.entry-content kbd{padding:.15em .35em;border-radius:4px;background:#eef1f5;font-size:.9em}.entry-content pre{overflow:auto;padding:18px;border-radius:9px;background:#172033;color:#f7f8fa}.entry-content pre code{padding:0;background:transparent;color:inherit}.entry-content figure{margin:1.5em 0}.entry-content figcaption{color:var(--color-text-light);font-size:.86rem;text-align:center}.entry-content .alignwide{max-width:980px;margin-left:50%;transform:translateX(-50%);width:min(980px,100vw - 32px)}.thao-note,.thao-tip,.thao-warning,.thao-success,.thao-quick-answer,.is-style-thao-note,.is-style-thao-tip,.is-style-thao-warning,.is-style-thao-success,.is-style-thao-quick-answer{margin:1.5em 0;padding:18px 20px;border:1px solid #cfe0f8;border-left:4px solid var(--color-primary);border-radius:9px;background:#f4f8ff}.thao-tip,.is-style-thao-tip,.thao-success,.is-style-thao-success{border-color:#b9e2d2;border-left-color:var(--color-success);background:#f0faf6}.thao-warning,.is-style-thao-warning{border-color:#f0d5aa;border-left-color:var(--color-warning);background:#fff8ed}.thao-quick-answer,.is-style-thao-quick-answer{padding:22px;border-width:1px 1px 1px 5px}.toc{border:1px solid var(--color-border);border-radius:10px;background:var(--color-surface);font-size:.89rem}.toc summary{padding:14px 16px;font-weight:800;cursor:pointer}.toc nav{padding:0 16px 14px}.toc ol{margin:0;padding-left:20px}.toc li{margin:7px 0}.toc a{color:var(--color-text-light);text-decoration:none}.toc-level-3{margin-left:12px!important}.toc-column,.related-column{display:none}.mobile-toc{margin-bottom:24px}.mobile-related{max-width:780px;margin:48px auto 0;border-top:1px solid var(--color-border)}.related-posts h2{font-size:1.15rem}.link-list li{margin:10px 0}.link-list a{color:var(--color-text);text-decoration:none}.narrow-page{max-width:820px;padding-bottom:70px}.error-page{max-width:760px;padding:80px 16px;text-align:center}.error-page .search-form{margin:30px auto;max-width:650px}.error-code{margin:0;color:var(--color-primary);font-size:1rem;font-weight:800}.error-page h1{font-size:clamp(2rem,6vw,3rem)}.quick-links{display:flex;justify-content:center;flex-wrap:wrap;gap:10px}.quick-links a{padding:8px 14px;border:1px solid var(--color-border);border-radius:8px;text-decoration:none}.comments-area{margin-top:50px;padding-top:30px;border-top:1px solid var(--color-border)}.comment-list{padding-left:22px}.comment-body{margin-bottom:24px}.comment-form input:not([type=submit]),.comment-form textarea{width:100%;border:1px solid #cbd2dc;border-radius:7px;padding:10px}.form-submit input{border:0;border-radius:8px;padding:11px 18px;background:var(--color-primary);color:#fff}.site-footer{padding:48px 0 20px;background:#121a2a;color:#d8deea}.site-footer .text-logo,.site-footer a{color:#fff}.footer-grid{display:grid;gap:30px}.footer-grid h2{font-size:1rem}.footer-links li{margin:8px 0}.footer-links a{text-decoration:none;color:#cbd3df}.copyright{margin-top:32px;padding-top:18px;border-top:1px solid #30394a;color:#9fa9b9;font-size:.85rem}
@media(min-width:768px){body{font-size:17px}.category-grid{grid-template-columns:repeat(3,1fr)}.topic-grid{grid-template-columns:repeat(2,1fr)}.footer-grid{grid-template-columns:2fr 1fr 1fr}.hero{padding:84px 0}.section{padding-top:72px;padding-bottom:72px}}
@media(min-width:1024px){.menu-toggle{display:none}.primary-nav{display:block;position:static;padding:0;border:0;background:transparent}.primary-nav ul{display:flex;gap:6px}.primary-nav a{padding:9px 12px}.topic-grid{grid-template-columns:repeat(3,1fr)}.article-layout{grid-template-columns:minmax(160px,220px) minmax(0,780px) minmax(160px,220px);gap:34px;justify-content:center}.toc-column,.related-column{display:block}.toc-column .toc{position:sticky;top:calc(var(--header-height) + 24px)}.related-column .related-posts{position:sticky;top:calc(var(--header-height) + 24px)}.mobile-toc,.mobile-related{display:none}.entry-content{font-size:18px}}
/* Featured images retain their intrinsic ratio to avoid layout shift. */
.entry-featured-image{margin:0 0 30px}.entry-featured-image img{display:block;width:100%;height:auto;border:1px solid var(--color-border);border-radius:var(--radius);background:var(--color-surface)}
/* Keep the Vietnamese hero headline visually balanced without orphaned words. */
.hero-inner{max-width:1100px}.hero h1{max-width:1050px;margin-right:auto;margin-left:auto;font-size:clamp(2.1rem,5.2vw,3.65rem);line-height:1.12;text-wrap:balance}.hero p:not(.eyebrow){max-width:760px;margin-right:auto;margin-left:auto;text-wrap:balance}
@media(max-width:767px){.hero h1{font-size:clamp(2rem,10.5vw,2.8rem)}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important}}