/* Giúp Học: landing page adapted from the supplied LearnUp template. */
:root{--maincolor:#1956d4;--headingcolor:#172c42;--bodycolor:#586574;--primaryfont:Arial,"Helvetica Neue",sans-serif;--gh-blue:#1956d4;--gh-ink:#172c42;--gh-muted:#5a6878;--gh-line:#e4e9ef}
html{scroll-behavior:smooth;scroll-padding-top:100px}
body{margin:0;background:#fff;color:var(--gh-muted);font-family:var(--primaryfont);font-size:16px;line-height:1.65;-webkit-font-smoothing:antialiased}
h1,h2,h3,h4,p{font-family:inherit}h1,h2,h3{text-transform:none;color:var(--gh-ink);letter-spacing:-.045em;font-weight:700}p{margin:0 0 1rem}a{text-decoration:none}button{font:inherit}button,a,summary{-webkit-tap-highlight-color:transparent}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid #eeab27;outline-offset:5px}section{padding:0;scroll-margin-top:20px}.container{max-width:1192px;padding-left:24px;padding-right:24px}
.skip-link{position:fixed;top:-70px;left:16px;z-index:200;background:var(--gh-ink);color:#fff;padding:10px 20px}.skip-link:focus{top:10px;color:#fff}.gh-header{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.97);border-bottom:1px solid var(--gh-line)}.gh-nav{min-height:88px;display:flex;justify-content:space-between;align-items:center;gap:32px}.gh-brand{display:inline-flex;align-items:center;font-size:27px;letter-spacing:-1px;font-weight:800;color:var(--gh-ink);white-space:nowrap}.gh-brand:hover{color:var(--gh-ink)}.gh-brand-dot{color:var(--gh-blue)}.gh-brand-mark{height:42px;width:42px;border-radius:12px;margin-right:11px;display:grid;place-items:center;background:var(--gh-blue);color:white}.gh-brand-mark svg{width:30px;height:30px}.gh-links{display:flex;align-items:center;gap:34px}.gh-links>a:not(.gh-button){color:#415164;font-weight:600;font-size:14px}.gh-links>a:hover{color:var(--gh-blue)}.gh-button{display:inline-flex;align-items:center;justify-content:center;gap:28px;background:var(--gh-blue);border:1px solid var(--gh-blue);border-radius:7px;color:#fff;font-size:15px;font-weight:700;line-height:1.4;padding:17px 24px;transition:background .15s,transform .15s;cursor:pointer}.gh-button:hover{background:#1246b0;border-color:#1246b0;color:#fff;transform:translateY(-2px)}.gh-button span{font-size:23px;line-height:1}.gh-button-small{padding:12px 18px;font-size:14px;gap:17px}.gh-links>.gh-button:hover{color:white}.gh-menu-button{display:none}
.gh-hero{padding:72px 0 64px;background:#f8faff;overflow:hidden}.gh-eyebrow{font-size:11px;letter-spacing:1.6px;font-weight:800;color:var(--gh-blue);line-height:1.8;margin-bottom:20px}.gh-small-star{color:#ed9a29;font-size:20px;margin-right:7px;vertical-align:-2px}.gh-hero h1{font-size:clamp(45px,5.2vw,67px);line-height:1.15;margin:0 0 25px;letter-spacing:-3px}.gh-hero h1>span{color:var(--gh-blue)}.gh-intro{max-width:475px;font-size:16px;line-height:1.9;margin-bottom:28px}.gh-hero-actions{display:flex;align-items:center;gap:23px;flex-wrap:wrap}.gh-text-link{display:inline-flex;align-items:center;gap:12px;color:var(--gh-ink);font-size:14px;font-weight:700}.gh-text-link:hover{color:var(--gh-blue)}.gh-hero-note{font-size:11px;display:flex;align-items:center;gap:10px;margin-top:30px;color:#667589}.gh-note-line{width:25px;height:2px;background:#a4b8db;flex-shrink:0}.gh-hero-visual{position:relative;padding:10px 12px 25px 32px}.gh-hero-visual>img{width:100%;height:auto;display:block;position:relative}.gh-visual-star{position:absolute;top:0;left:22%;font-size:65px;line-height:1;color:#1956d4;transform:rotate(8deg)}.gh-study-note{display:flex;align-items:center;gap:13px;background:#fff;border:1px solid #edf0f4;box-shadow:0 14px 45px #263b6412;padding:16px 20px;border-radius:10px;position:absolute;bottom:8px;left:25%;transform:rotate(-3deg)}.gh-study-note strong,.gh-study-note span:not(.gh-check){display:block}.gh-study-note strong{font-size:13px;color:var(--gh-ink)}.gh-study-note span:not(.gh-check){font-size:11px;color:#768192}.gh-check{display:grid;place-items:center;width:35px;height:35px;background:#e5f4ed;color:#218052;border-radius:50%;font-weight:bold}
.gh-principles{background:#fff;border-top:1px solid var(--gh-line);border-bottom:1px solid var(--gh-line)}.gh-principles-inner{display:flex;justify-content:space-between;gap:24px;padding-top:24px;padding-bottom:24px}.gh-principles-inner>span{font-size:14px;color:#44576b;font-weight:600}.gh-principles b{font-weight:400;color:#8095b4;margin-right:15px;font-size:12px}.gh-section{padding:88px 0}.gh-section h2,.gh-cta h2{font-size:37px;line-height:1.3;margin:0 0 20px}.gh-section-heading{display:flex;align-items:flex-end;justify-content:space-between;gap:40px;margin-bottom:35px}.gh-section-heading h2{margin-bottom:0}.gh-section-heading>p{margin:0 0 4px;font-size:14px;line-height:1.8}.gh-course{height:100%;border:1px solid var(--gh-line);border-radius:10px;overflow:hidden;box-shadow:none;display:flex;flex-direction:column;background:#fff;margin-bottom:0;transition:transform .2s,box-shadow .2s}.gh-course:hover{transform:translateY(-4px);box-shadow:0 14px 30px #162e4e0b}.gh-course-cover{height:195px;position:relative;overflow:hidden;padding:24px}.gh-cover-math{background:#e9efff;color:#3255b4}.gh-cover-english{background:#fff1dc;color:#a46229}.gh-cover-skills{background:#e4f1ec;color:#236855}.gh-cover-tag{font-size:9px;letter-spacing:1.3px;font-weight:700;position:relative;z-index:1}.gh-cover-index{position:absolute;right:14px;bottom:-16px;font-size:87px;font-weight:800;opacity:.085;letter-spacing:-7px;line-height:1.2}.gh-math-symbol{position:absolute;left:28px;top:63px;font-size:46px;font-family:Georgia,serif;font-style:italic;letter-spacing:1px;transform:rotate(-6deg)}.gh-cover-graph{width:145px;position:absolute;right:18px;bottom:9px}.gh-speech{position:absolute;background:#fff;border-radius:10px 10px 10px 0;padding:4px 16px;box-shadow:0 3px 0 #a4622910;font-weight:700;font-size:25px;line-height:1.5}.gh-speech-one{left:32px;top:62px;transform:rotate(-6deg)}.gh-speech-two{right:31px;bottom:31px;transform:rotate(6deg);color:#b1723a;font-size:20px}.gh-mini-list{position:absolute;top:65px;left:27px;display:flex;flex-direction:column;gap:9px;transform:rotate(-3deg)}.gh-mini-list>span{font-size:12px;line-height:1.9;background:#ffffffab;border-radius:4px;padding:2px 11px}.gh-mini-list b{margin-right:10px;color:#29805e}.gh-course-body{padding:25px;display:flex;flex-direction:column;flex:1}.gh-course-category{font-size:10px;letter-spacing:1.4px;color:var(--gh-blue);font-weight:700;margin-bottom:13px}.gh-course h3{font-size:23px;line-height:1.4;letter-spacing:-.65px;margin:0 0 12px}.gh-course-body>p:not(.gh-course-category){font-size:13px;line-height:1.8;margin-bottom:24px}.gh-course-link{margin-top:auto;display:flex;align-items:center;justify-content:space-between;border:0;border-top:1px solid var(--gh-line);background:transparent;width:100%;padding:16px 0 0;color:var(--gh-ink);font-size:13px;font-weight:700;cursor:pointer;text-align:left}.gh-course-link span{font-size:23px;line-height:1;color:var(--gh-blue)}.gh-course-link:hover{color:var(--gh-blue)}
.gh-method{background:#f6f8fb}.gh-method h2 span{color:var(--gh-blue)}.gh-method-intro{font-size:14px;max-width:350px;line-height:1.9;margin-bottom:24px}.gh-steps{list-style:none;padding:0 0 0 28px;margin:0}.gh-steps>li{display:flex;gap:24px;padding:26px 0;border-bottom:1px solid #dce3ed}.gh-steps>li:first-child{padding-top:0}.gh-steps>li:last-child{border-bottom:0;padding-bottom:0}.gh-step-number{font-size:15px;flex:0 0 45px;height:45px;display:grid;place-items:center;color:var(--gh-blue);background:#e9eef9;border-radius:50%;margin-top:2px}.gh-steps h3{font-size:19px;letter-spacing:-.5px;line-height:1.45;margin:0 0 8px}.gh-steps p{font-size:13px;line-height:1.8;margin:0;max-width:420px}.gh-faq p{font-size:14px}.gh-faq-list>details{border-bottom:1px solid var(--gh-line);padding:20px 0}.gh-faq-list>details:first-child{padding-top:0}.gh-faq-list summary{position:relative;list-style:none;color:var(--gh-ink);font-size:16px;font-weight:600;cursor:pointer;padding-right:30px}.gh-faq-list summary::-webkit-details-marker{display:none}.gh-faq-list summary::after{content:"+";position:absolute;right:0;top:-2px;color:var(--gh-blue);font-size:24px;font-weight:400}.gh-faq-list details[open]>summary::after{content:"−"}.gh-faq-list details p{padding:14px 30px 0 0;font-size:13px;line-height:1.9;margin:0}
.gh-cta-section{padding:0 0 64px}.gh-cta{background:#1956d4;border-radius:13px;padding:48px 50px;display:flex;align-items:center;justify-content:space-between;gap:35px;position:relative;overflow:hidden}.gh-cta>div,.gh-cta>a{z-index:1;position:relative}.gh-cta .gh-eyebrow{color:#c6d7ff}.gh-cta h2{color:#fff;font-size:36px;margin-bottom:15px}.gh-cta p:not(.gh-eyebrow){font-size:13px;color:#d3e0ff;max-width:450px;margin-bottom:0}.gh-button-white{background:#fff;border-color:#fff;color:#1956d4;white-space:nowrap}.gh-button-white:hover{background:#eaf0ff;border-color:#eaf0ff;color:#1546af}.gh-cta-star{position:absolute;right:30px;bottom:-100px;font-size:370px;line-height:1;opacity:.065;color:#fff;transform:rotate(10deg);pointer-events:none}.gh-footer{border-top:1px solid var(--gh-line);padding:28px 0 20px}.gh-footer-top{display:flex;align-items:center;justify-content:space-between;gap:20px;padding-bottom:22px}.gh-footer-top>.gh-brand{font-size:25px}.gh-footer-top p,.gh-footer-top>a:last-child{font-size:12px;margin:0;color:#627085}.gh-footer-bottom{border-top:1px solid #edf0f4;padding-top:18px;display:flex;justify-content:space-between;gap:15px;font-size:10px;color:#778294}
.gh-dialog{position:fixed;inset:0;border:1px solid var(--gh-line);border-radius:16px;padding:40px;max-width:550px;width:calc(100% - 32px);max-height:calc(100dvh - 40px);overflow:auto;margin:auto;color:var(--gh-muted);box-shadow:0 25px 90px #07162b40}.gh-dialog::backdrop{background:#0a1b38a6}.gh-dialog .gh-eyebrow{font-size:10px;margin:8px 24px 16px 0}.gh-dialog h2{font-size:29px;line-height:1.3;margin-bottom:16px}.gh-dialog p{font-size:14px;line-height:1.8}.gh-dialog-close{position:absolute;right:16px;top:11px;width:36px;height:36px;background:transparent;border:0;color:var(--gh-muted);font-size:30px;line-height:1;cursor:pointer}.gh-dialog ol{padding-left:22px;font-size:14px;margin:25px 0}.gh-dialog li{padding-left:8px;margin-bottom:15px}.gh-dialog li::marker{color:var(--gh-blue);font-weight:700}.gh-dialog .gh-dialog-note{font-size:11px;border-top:1px solid var(--gh-line);padding-top:14px;margin-top:25px}.gh-dialog .gh-button{font-size:13px;padding:13px 18px}
.gh-cover-literature{background:#f1eafb;color:#73519e}.gh-literature-quote{position:absolute;left:24px;top:43px;font:110px Georgia,serif;opacity:.3}.gh-literature-text{position:absolute;left:72px;top:77px;font:italic 23px/1.55 Georgia,serif;transform:rotate(-4deg)}.gh-cover-science{background:#e5f3fa;color:#267293}.gh-science-formula{position:absolute;left:24px;top:84px;font:italic 28px Georgia,serif;transform:rotate(-5deg)}.gh-science-formula span{opacity:.5;margin:0 6px}.gh-cover-social{background:#f7e9e5;color:#9c5b48}.gh-social-line{position:absolute;left:26px;right:26px;top:97px;display:flex;align-items:center;gap:13px;font:italic 20px Georgia,serif}.gh-social-line i{height:1px;background:currentColor;flex:1;position:relative}.gh-social-line i::after{content:"";width:7px;height:7px;border:1px solid currentColor;border-width:1px 1px 0 0;position:absolute;right:0;top:-3px;transform:rotate(45deg)}
@media(min-width:768px) and (max-width:991px){.gh-literature-text{font-size:18px;left:39px}.gh-science-formula{font-size:19px;left:15px}.gh-social-line{font-size:16px;left:17px;right:17px}}
@media(min-width:1440px){.gh-hero{padding-top:84px;padding-bottom:76px}}
@media(max-width:991px){.gh-nav{min-height:76px}.gh-links{gap:20px}.gh-hero{padding-top:48px}.gh-hero h1{font-size:62px}.gh-hero-copy{max-width:640px}.gh-hero-visual{max-width:560px;margin:25px auto 0;padding:0 20px 25px}.gh-hero-note{font-size:12px}.gh-principles-inner{gap:18px}.gh-principles-inner>span{font-size:12px}.gh-principles b{margin-right:6px}.gh-section{padding:65px 0}.gh-section h2{font-size:32px}.gh-section-heading{gap:24px}.gh-section-heading>p{max-width:220px;font-size:13px}.gh-course-cover{height:175px;padding:18px}.gh-cover-tag{font-size:8px;letter-spacing:.7px}.gh-course-body{padding:18px}.gh-course h3{font-size:19px}.gh-course-body>p:not(.gh-course-category){font-size:12px}.gh-math-symbol{font-size:35px;left:20px}.gh-speech-one{font-size:22px;left:15px}.gh-speech-two{font-size:15px;right:15px}.gh-mini-list{left:16px}.gh-mini-list>span{font-size:9px;padding:2px 8px}.gh-steps{padding-left:0}.gh-method-intro{max-width:550px}.gh-cta{padding:38px 32px}.gh-cta h2{font-size:31px}}
@media(max-width:767px){html{scroll-padding-top:86px}.container{padding-left:22px;padding-right:22px}.gh-nav{min-height:74px}.gh-brand{font-size:24px}.gh-brand-mark{width:36px;height:36px;border-radius:10px;margin-right:8px}.gh-brand-mark svg{width:27px;height:27px}.gh-menu-button{display:flex;flex-direction:column;justify-content:center;gap:5px;align-items:center;width:42px;height:42px;padding:8px;border:1px solid var(--gh-line);border-radius:6px;background:#fff;cursor:pointer}.gh-menu-button span{display:block;background:var(--gh-ink);height:2px;width:20px}.gh-links{display:none;position:absolute;top:74px;left:0;right:0;background:#fff;padding:22px;box-shadow:0 15px 20px #243b5b10;border-bottom:1px solid var(--gh-line);flex-direction:column;align-items:stretch;gap:0}.gh-links.is-open{display:flex}.gh-links>a:not(.gh-button){padding:12px 0}.gh-links>.gh-button{margin-top:10px}.gh-hero{padding:38px 0 32px}.gh-eyebrow{font-size:10px;letter-spacing:1.1px;margin-bottom:16px}.gh-small-star{font-size:17px}.gh-hero h1{font-size:49px;letter-spacing:-2.5px;line-height:1.15;margin-bottom:22px}.gh-intro{font-size:14px;line-height:1.85;max-width:450px;margin-bottom:23px}.gh-hero-actions{gap:20px}.gh-button{font-size:13px;padding:15px 18px;gap:21px}.gh-text-link{font-size:12px}.gh-hero-note{font-size:10px;line-height:1.6;margin-top:24px}.gh-hero-visual{max-width:470px;margin-top:5px}.gh-visual-star{font-size:50px}.gh-study-note{padding:12px 15px;left:23%;bottom:0;gap:10px}.gh-study-note strong{font-size:11px}.gh-study-note span:not(.gh-check){font-size:10px}.gh-check{width:30px;height:30px}.gh-principles-inner{flex-direction:column;gap:11px;padding-top:19px;padding-bottom:19px}.gh-principles-inner>span{font-size:12px}.gh-principles b{margin-right:17px}.gh-section{padding:53px 0}.gh-section h2{font-size:29px;letter-spacing:-1.1px}.gh-section-heading{align-items:flex-start;flex-direction:column;gap:16px;margin-bottom:26px}.gh-section-heading>p{max-width:none;font-size:13px}.gh-section-heading>p br{display:none}.gh-course-cover{height:185px;padding:22px}.gh-cover-tag{font-size:9px;letter-spacing:1.3px}.gh-course-body{padding:24px}.gh-course h3{font-size:24px}.gh-course-body>p:not(.gh-course-category){font-size:13px}.gh-math-symbol{font-size:47px;left:34px}.gh-cover-graph{width:175px;right:20px;bottom:10px}.gh-speech-one{font-size:28px;left:39px}.gh-speech-two{font-size:22px;right:32px}.gh-mini-list{left:33px}.gh-mini-list>span{font-size:12px;padding:2px 11px}.gh-steps>li{gap:17px;padding:24px 0}.gh-steps h3{font-size:18px}.gh-step-number{flex-basis:39px;height:39px;font-size:13px}.gh-faq-list summary{font-size:15px}.gh-cta-section{padding-bottom:40px}.gh-cta{padding:30px 26px;flex-direction:column;align-items:flex-start;gap:26px}.gh-cta h2{font-size:28px}.gh-cta p:not(.gh-eyebrow){font-size:12px}.gh-cta .gh-eyebrow{font-size:9px}.gh-cta-star{font-size:260px;right:-10px;bottom:-55px}.gh-footer-top{flex-wrap:wrap;gap:12px}.gh-footer-top>p{order:3;flex-basis:100%;font-size:11px}.gh-footer-top>a:last-child{font-size:11px}.gh-footer-bottom{font-size:9px}.gh-dialog{padding:30px 24px}.gh-dialog h2{font-size:25px}}
@media(max-width:360px){.gh-hero h1{font-size:44px}.gh-hero-actions{gap:15px}.gh-hero .gh-text-link{font-size:11px}.gh-study-note{left:18%}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{transition:none!important;animation:none!important}}

/* Vietnamese typography, bundled locally for offline use. */
:root{--primaryfont:"Be Vietnam Pro",Arial,sans-serif}
body{font-weight:400;line-height:1.8}
.gh-brand{font-weight:700;font-size:26px;letter-spacing:-1.1px}
.gh-hero h1{font-size:clamp(44px,4.6vw,62px);font-weight:700;letter-spacing:-2.7px;line-height:1.25}
.gh-section h2,.gh-cta h2{font-weight:600;letter-spacing:-1.45px;line-height:1.45}
.gh-course h3,.gh-steps h3{font-weight:600;line-height:1.6;letter-spacing:-.65px}
.gh-eyebrow{font-weight:600;letter-spacing:1.25px}
.gh-links>a:not(.gh-button),.gh-button,.gh-text-link,.gh-course-link{font-weight:600}
.gh-intro{font-size:15px;line-height:1.95}
.gh-course-category{font-size:9px;letter-spacing:1px;font-weight:600}
.gh-course-body>p:not(.gh-course-category){line-height:1.95}
.gh-principles-inner>span{font-size:13px;font-weight:500}
.gh-footer-top>.gh-brand{font-size:24px}
.gh-dialog h2{font-weight:600;letter-spacing:-1px;line-height:1.5}
@media(max-width:991px){.gh-hero h1{font-size:58px}.gh-brand{font-size:23px}.gh-principles-inner>span{font-size:11px}.gh-links{gap:22px}.gh-links>a:not(.gh-button){font-size:12px}.gh-course h3{font-size:19px}.gh-course-category{font-size:8px;letter-spacing:.5px}}
@media(max-width:767px){.gh-hero h1{font-size:43px;letter-spacing:-1.9px;line-height:1.28}.gh-brand{font-size:23px}.gh-intro{font-size:13px;line-height:1.95}.gh-section h2{font-size:27px;letter-spacing:-1px}.gh-course h3{font-size:22px}.gh-course-category{font-size:9px;letter-spacing:.9px}.gh-principles-inner>span{font-size:12px}.gh-hero-actions{gap:17px}.gh-hero-actions>.gh-text-link{font-size:11px}.gh-cta h2{font-size:27px}.gh-links>a:not(.gh-button){font-size:14px}}
@media(max-width:360px){.gh-hero h1{font-size:38px;letter-spacing:-1.7px}.gh-hero-actions{gap:14px}}

/* Brand signature: open book, rising pages and a spark of understanding. */
.gh-brand{gap:11px;letter-spacing:normal;line-height:1;flex-shrink:0}
.gh-logo-symbol{display:block;width:52px;height:52px;flex-shrink:0}
.gh-wordmark{display:flex;flex-direction:column;gap:7px;padding-top:2px}
.gh-wordmark-name{font-size:28px;font-weight:600;line-height:1.25;letter-spacing:-1.25px;color:#173864}
.gh-wordmark-name>span{color:#1956d4}
.gh-wordmark-tagline{font-size:7.6px;line-height:1.4;font-weight:500;letter-spacing:1.65px;color:#62748b;padding-left:1px}
.gh-subject-note{font-size:11px;color:#748193;margin:21px 0 0;text-align:center}
.gh-footer-top>.gh-brand .gh-logo-symbol{width:46px;height:46px}
.gh-footer-top>.gh-brand .gh-wordmark-name{font-size:25px}
.gh-footer-top>.gh-brand .gh-wordmark-tagline{font-size:6.8px;letter-spacing:1.5px}
@media(max-width:991px){.gh-brand{gap:8px}.gh-logo-symbol{width:46px;height:46px}.gh-wordmark-name{font-size:25px}.gh-wordmark-tagline{font-size:6.8px;letter-spacing:1.5px}.gh-wordmark{gap:5px}}
@media(max-width:767px){.gh-logo-symbol{width:43px;height:43px}.gh-wordmark-name{font-size:24px;letter-spacing:-1px}.gh-wordmark-tagline{font-size:6.5px;letter-spacing:1.45px}.gh-wordmark{gap:4px}.gh-subject-note{font-size:10px;text-align:left}.gh-footer-top>.gh-brand .gh-logo-symbol{width:43px;height:43px}.gh-footer-bottom{flex-wrap:wrap}}