.site-header{z-index:20;background:var(--white);grid-template-columns:auto 1fr auto;align-items:center;gap:32px;min-height:88px;padding:0 11vw;display:grid;position:sticky;top:0;box-shadow:0 10px 20px #2832640d}.brand-link{align-items:center;display:inline-flex}.brand-logo{width:94px;height:auto}.primary-nav,.header-actions,.hero-actions{align-items:center;display:flex}.primary-nav{gap:22px}.nav-link{color:#df1843;white-space:nowrap;font-size:15px;font-weight:700}.nav-link:hover{color:var(--viettel-red-dark)}.header-actions{gap:14px}.icon-button{width:40px;height:40px;color:var(--viettel-red);border-left:1px solid #0000;place-items:center;display:grid;position:relative}.notification-dot{width:18px;height:18px;color:var(--white);background:var(--viettel-red);border-radius:50%;place-items:center;font-size:11px;font-weight:800;display:grid;position:absolute;top:4px;right:1px}@media (max-width:980px){.site-header{grid-template-columns:1fr auto;padding:14px 24px}.primary-nav{grid-column:1/-1;padding-bottom:8px;overflow-x:auto}}
.hero,.article-hero{grid-template-columns:minmax(0,1fr) minmax(320px,.9fr);align-items:center;gap:48px;padding:72px 11vw;display:grid;overflow:hidden}.hero-hub,.hero-support,.article-hero{color:var(--white);background:radial-gradient(circle at 72% 18%, #ffffff3d, transparent 25%), linear-gradient(135deg, var(--viettel-red), var(--viettel-red-dark))}.hero-docs{color:var(--ink);background:var(--soft)}.eyebrow,.section-heading span,.article-category{color:var(--viettel-red);text-transform:uppercase;font-size:13px;font-weight:800}.hero-hub .eyebrow,.hero-support .eyebrow,.article-hero .eyebrow{color:var(--white)}.hero h1,.article-hero h1{max-width:760px;margin:12px 0 16px;font-size:clamp(34px,5vw,58px);font-weight:500;line-height:1.08}.hero p,.article-hero p{max-width:720px;margin:0;font-size:18px;font-weight:700;line-height:1.65}.hero-actions{flex-wrap:wrap;gap:14px;margin-top:30px}.hero-visual img,.article-hero img{border-radius:8px;width:100%;box-shadow:0 24px 70px #0000002e}@media (max-width:980px){.hero,.article-hero{grid-template-columns:1fr;padding-left:24px;padding-right:24px}}
.promo-strip{background:var(--soft);grid-template-columns:repeat(3,1fr);padding:34px 11vw;display:grid}.promo-item{text-align:center;border-right:1px solid #aaa;min-height:96px;padding:10px 28px}.promo-item:last-child{border-right:0}.promo-item strong{color:var(--viettel-red);margin-bottom:12px;font-size:18px;display:block}.promo-item span,.section-heading p,.service-card p,.article-card p{color:var(--muted);line-height:1.6}.content-section{background:var(--white);padding:76px 11vw}.section-heading{text-align:center;max-width:820px;margin:0 auto 36px}.section-heading h2,.stats-band h2,.cta-band h2{margin:10px 0 12px;font-size:clamp(28px,4vw,38px);font-weight:700;line-height:1.15}.service-grid,.article-grid,.stats-grid{gap:22px;display:grid}.service-grid,.article-grid{grid-template-columns:repeat(3,minmax(0,1fr))}.service-card,.article-card{background:var(--white);border:1px solid var(--line);border-radius:8px;min-height:230px;padding:26px;transition:transform .18s,border-color .18s,box-shadow .18s}.service-card-link:hover,.article-card:hover{border-color:#ee00336b;transform:translateY(-4px);box-shadow:0 20px 48px #3232501a}.service-icon{width:54px;height:54px;color:var(--viettel-red);background:#ffe7e7;border-radius:8px;place-items:center;margin-bottom:20px;display:grid}.service-card h3,.article-card h3{margin:0 0 12px;font-size:20px}.stats-band,.cta-band{color:var(--white);background:var(--viettel-red);text-align:center;padding:62px 11vw}.stats-grid{grid-template-columns:repeat(3,1fr);max-width:980px;margin:30px auto 0}.stat-item strong{font-size:42px;display:block}.stat-item span{font-weight:700}.cta-band p{max-width:720px;margin:0 auto 26px;line-height:1.7}.article-section{background:var(--soft)}.article-card{min-height:260px}.article-meta{color:var(--viettel-red);margin-top:16px;font-weight:800;display:inline-flex}.article-content{max-width:880px;margin:0 auto;padding:58px 24px 90px}.article-block{margin-bottom:34px}.article-block h2{margin:0 0 12px;font-size:28px}.article-block p,.steps-list p,.callout p{color:var(--muted);line-height:1.75}.steps-list{gap:16px;padding-left:28px;display:grid}.callout{color:var(--ink);background:#fff5f6;border:1px solid #ffd7de;border-radius:8px;gap:16px;margin:28px 0;padding:22px;display:flex}.callout svg{color:var(--viettel-red);flex:none}@media (max-width:980px){.promo-strip,.service-grid,.article-grid,.stats-grid{grid-template-columns:1fr}.content-section,.stats-band,.cta-band,.promo-strip{padding-left:24px;padding-right:24px}.promo-item{border-bottom:1px solid #ddd;border-right:0}.promo-item:last-child{border-bottom:0}}
.product-catalog-section{border-top:1px solid var(--line);background:#f9fafb;padding:76px 11vw}.product-catalog-heading{justify-content:space-between;align-items:flex-start;gap:32px;margin-bottom:28px;display:flex}.product-catalog-heading h2{margin:10px 0 12px;font-size:clamp(28px,4vw,38px);line-height:1.15}.product-catalog-heading p,.product-catalog-empty p,.product-catalog-card p{color:var(--muted);line-height:1.6}.product-catalog-source,.product-catalog-meta,.product-catalog-card-top,.product-catalog-price{align-items:center;display:flex}.product-catalog-source{min-height:38px;color:var(--viettel-red);white-space:nowrap;background:#fff0f2;border:1px solid #ffd3dc;border-radius:999px;gap:8px;padding:0 14px;font-weight:800}.product-catalog-meta{color:var(--muted);flex-wrap:wrap;gap:12px;margin-bottom:22px;font-size:14px;font-weight:800}.product-catalog-meta span,.product-catalog-meta a{background:var(--white);border:1px solid var(--line);border-radius:999px;padding:8px 12px}.product-catalog-meta a{color:var(--viettel-red)}.product-catalog-grid{grid-template-columns:repeat(4,minmax(0,1fr));gap:18px;display:grid}.product-catalog-card,.product-catalog-empty{background:var(--white);border:1px solid var(--line);border-radius:8px}.product-catalog-card{min-height:270px;padding:22px;display:grid}.product-catalog-card-top{color:var(--viettel-red);text-transform:uppercase;justify-content:space-between;gap:12px;font-size:13px;font-weight:900}.product-catalog-card-top small{color:#1f7a3f;text-transform:none}.product-catalog-card h3,.product-catalog-empty h3{margin:18px 0 10px;font-size:20px}.product-catalog-price{border-top:1px solid var(--line);justify-content:space-between;align-self:end;gap:16px;margin-top:20px;padding-top:18px}.product-catalog-price strong{color:var(--viettel-red);font-size:18px}.product-catalog-price span{color:var(--muted);text-align:right;font-size:13px;font-weight:800}.product-catalog-empty{align-items:flex-start;gap:16px;padding:24px;display:flex}.product-catalog-empty svg{color:var(--viettel-red);flex:none}@media (max-width:1180px){.product-catalog-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}@media (max-width:760px){.product-catalog-section{padding-left:24px;padding-right:24px}.product-catalog-heading,.product-catalog-price{display:grid}.product-catalog-source{justify-self:start}.product-catalog-grid{grid-template-columns:1fr}.product-catalog-price span{text-align:left}}
.docs-portal{background:#f7f7f7;padding:72px 11vw 88px}.docs-toolbar{grid-template-columns:minmax(0,1fr) minmax(280px,420px);align-items:end;gap:28px;margin-bottom:34px;display:grid}.docs-toolbar h2,.docs-topic h2{margin:8px 0 12px;font-size:32px;line-height:1.18}.docs-toolbar p,.docs-topic p,.docs-panel p{color:var(--muted);line-height:1.65}.docs-search-box{color:#555;background:var(--white);border:1px solid var(--line);border-radius:8px;align-items:center;gap:12px;min-height:58px;padding:0 18px;display:flex}.docs-layout{grid-template-columns:260px minmax(0,1fr);align-items:start;gap:28px;display:grid}.docs-sidebar{background:var(--white);border:1px solid var(--line);border-radius:8px;gap:12px;padding:18px;display:grid;position:sticky;top:112px}.docs-sidebar a{border-top:1px solid var(--line);justify-content:space-between;gap:12px;padding:10px 0;font-weight:800;display:flex}.docs-sidebar small,.doc-type,.doc-meta{color:var(--viettel-red);font-weight:800}.docs-main{gap:28px;display:grid}.docs-featured-grid,.docs-panels{grid-template-columns:repeat(2,minmax(0,1fr));gap:18px;display:grid}.doc-feature-card,.docs-panel,.docs-topic{background:var(--white);border:1px solid var(--line);border-radius:8px}.doc-feature-card,.docs-panel{padding:22px}.doc-feature-card{min-height:210px}.doc-feature-card svg,.docs-panel svg{color:var(--viettel-red)}.doc-feature-card span{color:var(--viettel-red);text-transform:uppercase;margin-top:14px;font-size:13px;font-weight:800;display:block}.doc-feature-card h3,.docs-panel h3,.doc-row h3{margin:10px 0;font-size:20px}.docs-panel{gap:10px;display:grid}.docs-panel a{color:var(--viettel-red);font-weight:800}.docs-topic{padding:28px;scroll-margin-top:120px}.docs-topic>div:first-child span{color:var(--viettel-red);text-transform:uppercase;font-size:13px;font-weight:800}.doc-row-list{border-top:1px solid var(--line);margin-top:20px;display:grid}.doc-row{border-bottom:1px solid var(--line);grid-template-columns:130px minmax(0,1fr) 150px;align-items:start;gap:18px;padding:18px 0;display:grid}@media (max-width:980px){.docs-portal{padding-left:24px;padding-right:24px}.docs-toolbar,.docs-layout,.docs-featured-grid,.docs-panels,.doc-row{grid-template-columns:1fr}.docs-sidebar{position:static}}
.support-center{background:#f7f7f7;padding:72px 11vw 88px}.support-search-band,.support-layout{gap:28px;display:grid}.support-search-band{grid-template-columns:minmax(0,1fr) minmax(280px,420px);align-items:end;margin-bottom:34px}.support-layout{grid-template-columns:minmax(0,1fr) 300px;align-items:start}.support-search-band h2,.popular-support h2{margin:8px 0 12px;font-size:32px;line-height:1.18}.support-search-band p,.support-category-card p,.support-contact-card p,.qa-item p{color:var(--muted);line-height:1.65}.support-search-box{color:#555;background:var(--white);border:1px solid var(--line);border-radius:8px;align-items:center;gap:12px;min-height:58px;padding:0 18px;display:flex}.support-main,.support-aside,.qa-list{gap:18px;display:grid}.support-aside{position:sticky;top:112px}.support-section-title{align-items:center;gap:12px;display:flex}.support-section-title svg,.support-category-card svg,.support-contact-card svg{color:var(--viettel-red)}.support-category-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:18px;display:grid}.support-category-card,.support-contact-card,.qa-item{background:var(--white);border:1px solid var(--line);border-radius:8px;padding:22px}.support-category-card span,.qa-item summary span{color:var(--viettel-red);text-transform:uppercase;font-size:13px;font-weight:800}.support-category-card span{margin-top:14px;display:block}.support-category-card h3,.support-contact-card h3{margin:10px 0;font-size:20px}.support-category-card strong,.qa-item a,.support-contact-card a{color:var(--viettel-red);margin-top:12px;font-weight:800;display:block}.qa-item summary{cursor:pointer;grid-template-columns:110px minmax(0,1fr);gap:14px;font-size:18px;display:grid}@media (max-width:980px){.support-center{padding-left:24px;padding-right:24px}.support-search-band,.support-layout,.support-category-grid,.qa-item summary{grid-template-columns:1fr}.support-aside{position:static}}
.article-hero-docs{color:var(--ink);background:#f5f5f5}.article-hero-docs .eyebrow{color:var(--viettel-red)}.article-meta-row,.tag-list{flex-wrap:wrap;gap:10px;margin-top:22px;display:flex}.article-meta-row span,.tag-list small{color:var(--viettel-red);background:#fff0f2;border-radius:999px;padding:7px 10px;font-weight:800}.article-layout,.support-article-layout{align-items:start;gap:34px;padding:58px 11vw 90px;display:grid}.article-layout{grid-template-columns:260px minmax(0,880px)}.support-article-layout{grid-template-columns:minmax(0,820px) 320px}.article-layout .article-content,.support-article-layout .article-content{padding:0}.article-toc,.support-channel-list,.support-detail-section{background:var(--white);border:1px solid var(--line);border-radius:8px;padding:22px}.article-toc,.support-channel-list{gap:12px;display:grid;position:sticky;top:112px}.support-detail-section{margin-bottom:24px}.support-detail-section li,.support-channel-list p{color:var(--muted);line-height:1.65}.support-channel-list span{color:var(--viettel-red);align-items:center;gap:8px;font-weight:800;display:inline-flex}@media (max-width:980px){.article-layout,.support-article-layout{grid-template-columns:1fr;padding-left:24px;padding-right:24px}.article-toc,.support-channel-list{position:static}}
.site-footer{color:#252525;border-top:3px solid var(--viettel-red);background:#f7f7f7;padding-top:32px;font-size:14px}.site-footer__container{width:min(1120px,100% - 32px);margin:0 auto}.site-footer__main{grid-template-columns:minmax(260px,.95fr) minmax(0,2fr);gap:52px;display:grid}.site-footer__logo{width:154px;margin-bottom:18px}.site-footer__company p{text-align:justify;margin:0 0 14px;line-height:1.55}.site-footer__contact{gap:4px;margin-top:18px;display:grid}.site-footer a{color:inherit}.site-footer__contact a{color:var(--viettel-red)}.site-footer__social{flex-wrap:wrap;gap:7px;margin-top:12px;display:flex}.site-footer__social a{justify-content:center;align-items:center;width:22px;height:22px;display:inline-flex}.site-footer__columns{grid-template-columns:repeat(3,minmax(0,1fr));gap:26px;display:grid}.site-footer__column h2{color:#111;margin:0 0 8px;font-size:16px;font-weight:800;line-height:1.35}.site-footer__column ul{gap:10px;margin:0;padding:0;list-style:none;display:grid}.site-footer__column a{color:#515151;font-size:14px;line-height:1.35}.site-footer__column a:hover{color:var(--viettel-red)}.site-footer__bottom{border-top:1px solid #949595;grid-template-columns:minmax(0,1fr) auto;align-items:center;gap:20px;margin-top:28px;padding:14px 0 16px;display:grid}.site-footer__bottom small{color:#252525}.site-footer__badges{flex-wrap:wrap;justify-content:flex-end;align-items:center;gap:10px;display:flex}.site-footer__badges a{max-width:100px;display:inline-flex}.site-footer__badges img{object-fit:contain;width:auto;max-height:30px}@media (max-width:980px){.site-footer__main,.site-footer__bottom{grid-template-columns:1fr}.site-footer__columns{grid-template-columns:repeat(2,minmax(0,1fr))}.site-footer__badges{justify-content:flex-start}}@media (max-width:640px){.site-footer__columns{grid-template-columns:1fr}}
:root{--viettel-red:#e03;--viettel-red-dark:#b6002a;--ink:#383838;--muted:#666;--line:#e7e7e7;--soft:#f5f5f5;--white:#fff}*{box-sizing:border-box}html{color:var(--ink);background:var(--white);letter-spacing:0;font-family:Sarabun,sans-serif}body{margin:0;font-family:Sarabun,sans-serif}a{color:inherit;text-decoration:none}img{max-width:100%;display:block}.button{border:1px solid var(--viettel-red);border-radius:6px;justify-content:center;align-items:center;min-height:46px;padding:0 24px;font-weight:800;display:inline-flex}.button-primary,.button-light:hover{color:var(--white);background:var(--viettel-red)}.button-secondary,.button-light{color:var(--viettel-red);background:var(--white)}.not-found{text-align:center;place-content:center;justify-items:center;min-height:100vh;padding:24px;display:grid}