:root{--bg:#fff;--alt:#F3F5F8;--surface:#fff;--fg:#0B1F3A;--muted:#4A5B73;--rule:#D5DCE6;--navy:#0B1F3A;--navy2:#13305A;--gold:#D4AF37;--accent:#8A6508;
--display:'Source Serif 4',Georgia,serif;--body:'Be Vietnam Pro','Segoe UI',system-ui,sans-serif}
@media (prefers-color-scheme:dark){:root{--bg:#0A1627;--alt:#0E1D35;--surface:#102240;--fg:#EEF2F8;--muted:#A9B6C8;--rule:#26395A;--accent:#D4AF37;color-scheme:dark}}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--fg);font-family:var(--body);font-size:17px;line-height:1.65}
html[data-lang="vi"] .en,html[data-lang="en"] .vi{display:none}
img{max-width:100%;height:auto}
a{color:inherit}
.in{max-width:1120px;margin:0 auto;padding-inline:max(20px,env(safe-area-inset-left,0px))}
.skip{position:absolute;left:-999px;top:0;background:var(--gold);color:#000;padding:8px 14px;z-index:99}.skip:focus{left:8px}
:focus-visible{outline:3px solid var(--gold);outline-offset:2px}
/* top bar */
.topbar{background:var(--navy);color:#DDE5F1;font-size:13.5px}
.topbar .in{display:flex;justify-content:space-between;align-items:center;gap:12px;min-height:38px;flex-wrap:wrap;padding-block:4px}
.tb-right{display:flex;align-items:center;gap:18px;flex-wrap:wrap}
.tb-right a{text-decoration:none}.tb-right a:hover{text-decoration:underline}
.lang{display:inline-flex;border:1px solid #3B5580;border-radius:5px;overflow:hidden}
.lang button{font:inherit;font-size:12.5px;padding:3px 11px;border:0;background:transparent;color:#DDE5F1;cursor:pointer}
.lang button[aria-pressed="true"]{background:var(--gold);color:#0B1F3A;font-weight:600}
@media(max-width:700px){.tb-left{display:none}.tb-right a:nth-child(2){display:none}}
/* header */
header.site{background:var(--bg);border-bottom:1px solid var(--rule);position:sticky;top:0;z-index:50}
header.site .in{max-width:1260px;display:flex;align-items:center;justify-content:space-between;gap:16px;min-height:76px}
.logo{display:flex;align-items:center;gap:12px;text-decoration:none}
.logo img{height:48px;width:auto;border-radius:4px}
.logo b{display:block;white-space:nowrap;font-family:var(--display);font-size:19px;line-height:1.1}
.logo small{display:none;color:var(--muted);font-size:12px;letter-spacing:.04em}
#nav{display:flex;align-items:center;gap:14px}
#nav>ul{display:flex;gap:4px;list-style:none;margin:0;padding:0}
#nav li{position:relative}
#nav li>a{display:block;padding:10px 9px;white-space:nowrap;text-decoration:none;font-weight:500;font-size:14.5px;border-bottom:3px solid transparent}
#nav li>a:hover,#nav li>a[aria-current]{border-bottom-color:var(--gold)}
.caret{display:none}
.sub{display:none;position:absolute;left:0;top:100%;min-width:270px;background:var(--surface);border:1px solid var(--rule);border-top:3px solid var(--gold);box-shadow:0 12px 30px rgba(11,31,58,.16);padding:8px 0;z-index:60}
.sub a{display:block;padding:9px 18px;text-decoration:none;font-size:15px}
.sub a:hover{background:var(--alt)}
.has-sub:hover>.sub,.has-sub:focus-within>.sub,.has-sub.open>.sub{display:block}
.menu{display:none;font:inherit;font-weight:600;border:2px solid var(--navy);background:transparent;color:var(--fg);padding:8px 14px;border-radius:6px;cursor:pointer}
/* buttons */
.btn{display:inline-block;text-decoration:none;font-weight:600;font-size:16px;padding:13px 22px;border-radius:6px;border:2px solid var(--navy);cursor:pointer}
.btn.primary{background:var(--navy);color:#fff}
.btn.gold{background:var(--gold);border-color:var(--gold);color:#0B1F3A}
.btn.ghost{border-color:var(--rule)}
.btn.ghost-w{border-color:#7C93B8;color:#fff}
@media(prefers-color-scheme:dark){.btn.primary{border-color:var(--gold)}}
#nav .btn{padding:10px 16px;font-size:15px;white-space:nowrap}
.actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:20px}
/* hero */
.hero{background:linear-gradient(135deg,#0B1F3A 0%,#13305A 70%);color:#fff}
.hero-in{display:grid;grid-template-columns:1fr 340px;gap:40px;align-items:center;padding-block:56px}
.hero h1{font-family:var(--display);font-size:clamp(34px,5vw,54px);line-height:1.1;margin:0 0 18px;text-wrap:balance}
.hero .lede{font-size:19px;color:#D3DDED;max-width:52ch;margin:0}
.hero-img{width:340px;height:340px;object-fit:cover;object-position:50% 20%;border-radius:10px;border:3px solid var(--gold)}
.kicker{font-size:13px;letter-spacing:.12em;text-transform:uppercase;color:var(--gold);font-weight:600;margin:0 0 14px}
@media(max-width:860px){.hero-in{grid-template-columns:1fr;padding-block:36px}.hero-img{width:200px;height:200px;order:-1}}
/* path tiles */
.paths .in{display:grid;grid-template-columns:repeat(4,1fr);gap:0;transform:translateY(-28px)}
.path{background:var(--surface);border:1px solid var(--rule);padding:22px 20px;text-decoration:none;display:block;box-shadow:0 8px 24px rgba(11,31,58,.10)}
.path:hover{border-top:3px solid var(--gold);padding-top:20px}
.path b{display:block;font-family:var(--display);font-size:19px;margin-bottom:6px}
.path span{color:var(--muted);font-size:14.5px;line-height:1.5;display:block}
@media(max-width:900px){.paths .in{grid-template-columns:1fr 1fr}}
@media(max-width:520px){.paths .in{grid-template-columns:1fr}}
/* page head */
.phead{background:var(--alt);border-bottom:1px solid var(--rule)}
.phead .in{padding-block:44px 38px}
.phead h1{font-family:var(--display);font-size:clamp(30px,4.6vw,44px);line-height:1.12;margin:0 0 12px;text-wrap:balance}
.phead .kicker{color:var(--accent)}
.lede{font-size:18.5px;color:var(--muted);max-width:60ch;margin:0}
.crumbs{padding-block:14px 0;font-size:14px;color:var(--muted)}
.crumbs a{text-decoration:none}.crumbs a:hover{text-decoration:underline}
/* sections */
.blk{padding-block:48px}.blk.alt{background:var(--alt)}
.blk h2,.band h2{font-family:var(--display);font-size:clamp(25px,3.4vw,32px);line-height:1.2;margin:0 0 16px;text-wrap:balance}
p{margin:0 0 14px;max-width:68ch}
.grid2{display:grid;grid-template-columns:1fr 1fr;gap:22px}
.grid3{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:22px;margin-bottom:18px}
@media(max-width:760px){.grid2{grid-template-columns:1fr}}
.card{background:var(--surface);border:1px solid var(--rule);border-top:3px solid var(--gold);padding:22px;border-radius:4px}
.card h3{font-family:var(--display);font-size:20px;margin:0 0 8px}
.card.big{padding:28px}
.more{color:var(--accent);font-weight:600;text-decoration:none}.more:hover{text-decoration:underline}
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:0;border:1px solid var(--rule);background:var(--surface)}
.stats div{padding:24px 22px;border-right:1px solid var(--rule)}
.stats b{display:block;font-family:var(--display);font-size:28px;color:var(--accent);margin-bottom:6px}
.stats span{color:var(--muted);font-size:15px;line-height:1.45;display:block}
.src{font-size:13.5px;color:var(--muted);margin-top:14px}.src a{color:var(--accent)}
.note{background:var(--surface);border:1px solid var(--rule);border-left:4px solid var(--gold);padding:16px 18px;border-radius:4px;max-width:70ch;margin-bottom:6px}
.chips{list-style:none;padding:0;margin:16px 0 0;display:grid;grid-template-columns:repeat(auto-fill,minmax(210px,1fr));gap:10px}
.chips li{background:var(--surface);border:1px solid var(--rule);padding:11px 14px;border-radius:6px}
.chips b{display:block;color:var(--accent);letter-spacing:.05em}.chips span{font-size:14.5px;color:var(--muted)}
.covers{display:grid;grid-template-columns:repeat(auto-fit,minmax(140px,1fr));gap:16px;margin-bottom:18px}
.covers img{border-radius:6px;border:1px solid var(--rule);width:100%}
.books{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:26px;margin-bottom:10px}
.book img{width:100%;border-radius:6px;border:1px solid var(--rule)}
.book h3{font-family:var(--display);font-size:18px;margin:10px 0 4px;line-height:1.25}
.book p{color:var(--muted);font-size:15px;margin:0}
.plain{padding-left:20px;max-width:72ch}.plain li{margin-bottom:12px}
.split{display:grid;grid-template-columns:320px 1fr;gap:36px;align-items:start}
.split .portrait{width:320px;height:320px;object-fit:cover;border-radius:8px;border:1px solid var(--rule)}
.logo-big{width:300px;height:auto;border-radius:6px}
@media(max-width:760px){.split{grid-template-columns:1fr}.split .portrait{width:200px;height:200px}.logo-big{width:220px}}
.cred{margin:18px 0 0}.cred div{display:flex;gap:16px;padding:10px 0;border-bottom:1px solid var(--rule)}
.cred dt{min-width:110px;color:var(--muted);font-size:15px}.cred dd{margin:0}
/* CTA band */
.band.navy{background:var(--navy);color:#fff;padding-block:48px}
.cta{display:flex;justify-content:space-between;align-items:center;gap:28px;flex-wrap:wrap}
.cta p{color:#D3DDED;margin:0}
.cta .actions{margin:0}
/* footer */
footer.site{background:#08172B;color:#C5D0E2;padding-block:44px 28px;font-size:14.5px}
.fcols{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:28px;margin-bottom:28px}
.fcols h4{color:#fff;font-family:var(--display);font-size:17px;margin:0 0 12px}
.fcols a{display:block;text-decoration:none;padding:4px 0;color:#C5D0E2}.fcols a:hover{color:#fff;text-decoration:underline}
footer .legal{font-size:13px;max-width:none;color:#9FB0C9;border-top:1px solid #213554;padding-top:14px}
footer .legal a{color:#C5D0E2}
/* mobile nav */
@media(max-width:1039px){
 .menu{display:block}
 #nav{display:none;position:absolute;left:0;right:0;top:100%;background:var(--bg);border-bottom:1px solid var(--rule);flex-direction:column;align-items:stretch;padding:8px 20px 20px;gap:10px;max-height:80vh;overflow:auto}
 #nav.open{display:flex}
 #nav>ul{flex-direction:column}
 #nav li>a{border-bottom:1px solid var(--rule);padding:13px 4px;padding-right:50px}
 .caret{display:block;position:absolute;right:0;top:0;width:48px;height:48px;border:0;background:transparent;cursor:pointer}
 .caret::after{content:"+";font-size:24px;color:var(--fg)}
 .has-sub.open .caret::after{content:"−"}
 .sub{position:static;box-shadow:none;border:0;border-left:3px solid var(--gold);margin:0 0 6px 6px;min-width:0}
 .has-sub:hover>.sub,.has-sub:focus-within>.sub{display:none}.has-sub.open>.sub{display:block}
 header.site .in{position:relative}
}
.logo{margin-right:18px}
.logo{flex:none}#nav{min-width:0}

.logo img{height:54px}
@media(max-width:1239px){#nav li>a{padding:10px 7px;font-size:14px}#nav{gap:8px}#nav .btn{padding:9px 12px;font-size:14px}.logo{margin-right:8px}}
@media(min-width:1040px) and (max-width:1139px){#nav .btn.gold{display:none}}