:root{
  --navy:#081725;--navy-2:#102b42;--blue:#173b58;--paper:#fffdf7;--cream:#f6ead2;
  --gold:#d4a34a;--gold-soft:#f1d28e;--ink:#152638;--muted:#66727e;--line:rgba(255,255,255,.14);
  --bar-h:72px;--footer-h:76px;--turn-ms:520ms;
}
*{box-sizing:border-box}
html,body,button,a,input,select,textarea{font-family:Arial,"Arial Unicode MS","Segoe UI",Tahoma,sans-serif;text-rendering:auto;-webkit-font-smoothing:auto;-moz-osx-font-smoothing:auto}
html{scroll-behavior:smooth}
/* Chuẩn hóa font tiếng Việt: chỉ dùng Arial và các font hệ thống có đủ glyph tiếng Việt. */
body,body *:not(svg):not(path){font-family:Arial,"Arial Unicode MS","Segoe UI",Tahoma,sans-serif!important;font-variant-ligatures:none;font-kerning:auto}
button,input,select,textarea{font-family:Arial,"Arial Unicode MS","Segoe UI",Tahoma,sans-serif!important;line-height:1.35}

body{margin:0;min-height:100vh;background:radial-gradient(circle at 80% 10%,#1d496a 0,transparent 32%),linear-gradient(135deg,#172b36 0%,#102d46 52%,#071421 100%);color:#fff;font-family:Arial,"Arial Unicode MS","Segoe UI",Tahoma,sans-serif;overflow-x:hidden}
button,a{font:inherit}
button{border:0}
.ambient{position:fixed;inset:0;pointer-events:none;overflow:hidden;z-index:0}
.ambient span{position:absolute;width:5px;height:5px;border-radius:50%;background:var(--gold-soft);box-shadow:0 0 20px rgba(241,210,142,.7);opacity:.55;animation:float 9s ease-in-out infinite}
.ambient span:nth-child(1){left:8%;top:28%}.ambient span:nth-child(2){left:43%;top:77%;animation-delay:-3s}.ambient span:nth-child(3){right:8%;top:38%;animation-delay:-6s}
@keyframes float{50%{transform:translateY(-28px);opacity:.9}}
.topbar{position:sticky;top:0;z-index:50;height:var(--bar-h);display:grid;grid-template-columns:56px 1fr auto;align-items:center;gap:14px;padding:0 clamp(14px,3vw,34px);background:rgba(6,20,32,.93);border-bottom:1px solid rgba(255,255,255,.08);backdrop-filter:blur(16px)}
.brand{justify-self:center;text-decoration:none;color:#fff6df;display:flex;flex-direction:column;text-align:center;line-height:1.05}.brand strong{font:700 1.1rem/1.35 Arial,"Arial Unicode MS","Segoe UI",Tahoma,sans-serif;letter-spacing:.08em;text-transform:uppercase}.brand small{margin-top:5px;color:rgba(255,255,255,.62);font-size:.73rem}
.top-actions{display:flex;align-items:center;gap:8px}.icon-btn,.close-btn{width:42px;height:42px;border-radius:999px;display:grid;place-items:center;color:#fff;background:rgba(255,255,255,.05);border:1px solid var(--line);cursor:pointer;transition:.2s ease}.icon-btn:hover,.close-btn:hover{border-color:var(--gold);background:rgba(212,163,74,.16)}
.menu-btn{display:flex;flex-direction:column;justify-content:center;align-items:center;gap:4px}.menu-btn span{width:17px;height:2px;background:currentColor}.text-icon{font-size:1.06rem}.pill-link{height:42px;padding:0 16px;border-radius:999px;display:inline-flex;align-items:center;justify-content:center;text-decoration:none;color:#fff4d8;background:rgba(255,255,255,.05);border:1px solid var(--line);font-weight:700;cursor:pointer}.pill-link:hover{border-color:var(--gold);background:rgba(212,163,74,.16)}
.download-link{height:42px;padding:0 18px;border-radius:999px;display:inline-flex;align-items:center;text-decoration:none;color:#152638;background:linear-gradient(135deg,#f3d895,#d5a34d);font-weight:700;box-shadow:0 9px 22px rgba(0,0,0,.22)}
.reader-only{display:none!important}body.reading .reader-only{display:flex!important}
main{position:relative;z-index:2}
.intro-section{width:min(1280px,calc(100% - 32px));margin:0 auto;padding:42px 0 60px;display:grid;grid-template-columns:minmax(320px,.78fr) minmax(0,1.22fr);gap:clamp(34px,5vw,76px);align-items:center}
.intro-visual{position:sticky;top:100px;align-self:start;min-height:640px;display:flex;align-items:center;justify-content:center}.intro-visual img{position:relative;z-index:2;width:min(100%,520px);height:auto;filter:drop-shadow(0 35px 38px rgba(0,0,0,.38));animation:bookFloat 5.8s ease-in-out infinite}.mockup-glow{position:absolute;width:76%;aspect-ratio:1;border-radius:50%;background:radial-gradient(circle,rgba(231,190,100,.28),transparent 65%);filter:blur(12px)}@keyframes bookFloat{50%{transform:translateY(-10px)}}
.book-stamp{position:absolute;z-index:3;right:4%;bottom:12%;width:112px;height:112px;border-radius:50%;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;background:linear-gradient(135deg,#f4ddaa,#c88f32);color:#17283a;border:6px solid rgba(255,255,255,.7);box-shadow:0 18px 34px rgba(0,0,0,.28);transform:rotate(7deg)}.book-stamp strong{font:700 2rem/1.2 Arial,"Arial Unicode MS","Segoe UI",Tahoma,sans-serif;line-height:1}.book-stamp span{font-size:.68rem;font-weight:700;text-transform:uppercase;line-height:1.15;margin-top:4px}
.intro-content{padding:8px 0}.eyebrow{display:inline-flex;padding:8px 13px;border-radius:999px;background:rgba(212,163,74,.14);color:var(--gold-soft);font-size:.78rem;font-weight:700;line-height:1.45;letter-spacing:.02em;text-transform:none}.intro-content h1{margin:15px 0 12px;font:700 clamp(2.6rem,5vw,5rem)/1.08 Arial,"Arial Unicode MS","Segoe UI",Tahoma,sans-serif;color:#fff9ed}.intro-content h1 em{display:block;margin-top:10px;color:var(--gold-soft);font-size:.63em;font-style:normal}.intro-lead{max-width:820px;margin:0 0 22px;color:rgba(255,255,255,.76);font:400 clamp(1rem,1.5vw,1.2rem)/1.7 Arial,"Arial Unicode MS","Segoe UI",Tahoma,sans-serif}
.heart-note{padding:19px 22px;border-radius:20px;background:linear-gradient(135deg,rgba(255,255,255,.1),rgba(255,255,255,.045));border:1px solid rgba(255,255,255,.12);box-shadow:0 18px 40px rgba(0,0,0,.12)}.heart-note span{display:block;margin-bottom:8px;color:var(--gold-soft);font-size:.84rem;font-weight:700;line-height:1.45;text-transform:none;letter-spacing:0}.heart-note p{margin:0;color:rgba(255,255,255,.78);line-height:1.68;font-size:.93rem}
.value-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin:16px 0}.value-grid article{display:flex;gap:12px;min-height:144px;padding:17px;border-radius:18px;background:rgba(5,20,32,.42);border:1px solid rgba(255,255,255,.09)}.value-grid b{flex:0 0 auto;color:var(--gold);font:700 1rem/1.35 Arial,"Arial Unicode MS","Segoe UI",Tahoma,sans-serif}.value-grid h2{font-size:.95rem;margin:0 0 6px;color:#fff5dd}.value-grid p{font-size:.8rem;line-height:1.55;margin:0;color:rgba(255,255,255,.63)}
.outcome-box{padding:20px 22px;border-radius:22px;background:#fffaf0;color:var(--ink);box-shadow:0 22px 48px rgba(0,0,0,.18)}.outcome-box h2{margin:0 0 12px;font:700 1.25rem/1.35 Arial,"Arial Unicode MS","Segoe UI",Tahoma,sans-serif;color:#153a52}.outcome-box ul{margin:0;padding:0;list-style:none;display:grid;gap:8px}.outcome-box li{position:relative;padding-left:23px;color:#425160;font-size:.87rem;line-height:1.5}.outcome-box li:before{content:"✦";position:absolute;left:0;color:#b98025}.outcome-box>p{margin:13px 0 0;padding-top:12px;border-top:1px solid rgba(21,58,82,.13);font:italic 400 .9rem/1.55 Arial,"Arial Unicode MS","Segoe UI",Tahoma,sans-serif;color:#69532b}
.intro-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:18px}.primary-btn,.ghost-btn{min-height:48px;padding:0 21px;border-radius:999px;font-weight:700;cursor:pointer;transition:.2s ease}.primary-btn{color:#11283a;background:linear-gradient(135deg,#f5dda8,#d3a04a);box-shadow:0 14px 30px rgba(0,0,0,.22)}.primary-btn:hover{transform:translateY(-2px)}.ghost-btn{color:#fff;background:rgba(255,255,255,.07);border:1px solid rgba(255,255,255,.16)}.performance-note{margin:10px 0 0;color:rgba(255,255,255,.46);font-size:.78rem}
.reader-section{display:none;min-height:calc(100vh - var(--bar-h) - var(--footer-h));padding:16px clamp(12px,3vw,38px) 20px;grid-template-rows:auto 1fr auto;align-items:center}.reading .intro-section{display:none}.reading .reader-section{display:grid}
.reader-toolbar{width:min(100%,900px);margin:0 auto 12px;display:grid;grid-template-columns:1fr auto 1fr;align-items:center;gap:12px}.nav-btn{justify-self:start;min-height:42px;padding:0 15px;border-radius:999px;color:#fff;background:rgba(255,255,255,.06);border:1px solid var(--line);cursor:pointer;font-weight:700}.nav-btn:last-child{justify-self:end}.nav-btn:disabled{opacity:.35;cursor:not-allowed}.reader-title{text-align:center;display:flex;flex-direction:column;gap:3px}.reader-title span{font:700 .95rem/1.35 Arial,"Arial Unicode MS","Segoe UI",Tahoma,sans-serif;color:#fff5df}.reader-title strong{font-size:.72rem;color:rgba(255,255,255,.56)}
.page-stage{position:relative;width:min(100%,1120px,calc(141vh - 310px));aspect-ratio:1680/1191;margin:auto;perspective:2400px;user-select:none;touch-action:pan-y}
.page-shadow{position:absolute;left:7%;right:7%;bottom:-16px;height:34px;border-radius:50%;background:rgba(0,0,0,.46);filter:blur(18px)}
.spread-book{position:absolute;inset:0;transform-style:preserve-3d;will-change:transform,opacity}
.spread-page{position:absolute;top:0;bottom:0;width:50%;overflow:hidden;background:#f7f2e7;box-shadow:0 22px 46px rgba(0,0,0,.4)}
.spread-left{left:0;border-radius:15px 3px 3px 15px}
.spread-right{right:0;border-radius:3px 15px 15px 3px}
.spread-page img,.turn-face img{display:block;width:100%;height:100%;object-fit:contain;background:#f7f2e7}
.spread-left:after,.spread-right:after{content:"";position:absolute;top:0;bottom:0;width:8%;pointer-events:none;z-index:2}
.spread-left:after{right:0;background:linear-gradient(90deg,transparent,rgba(35,25,15,.18))}
.spread-right:after{left:0;background:linear-gradient(90deg,rgba(35,25,15,.18),transparent)}
.spread-gutter{position:absolute;z-index:6;left:50%;top:0;bottom:0;width:3px;transform:translateX(-50%);background:linear-gradient(90deg,rgba(0,0,0,.28),rgba(255,255,255,.42),rgba(0,0,0,.22));box-shadow:0 0 18px rgba(0,0,0,.34);pointer-events:none}
.turn-sheet{position:absolute;z-index:9;top:0;bottom:0;width:50%;display:none;transform-style:preserve-3d;will-change:transform}
.turn-sheet.is-active{display:block}
.turn-face{position:absolute;inset:0;overflow:hidden;backface-visibility:hidden;background:#f7f2e7;box-shadow:0 18px 40px rgba(0,0,0,.38)}
.turn-back{transform:rotateY(180deg)}
.turn-sheet.turn-next{left:50%;transform-origin:left center;animation:turnSpreadNext var(--turn-ms) cubic-bezier(.22,.72,.18,1) forwards}
.turn-sheet.turn-prev{left:0;transform-origin:right center;animation:turnSpreadPrev var(--turn-ms) cubic-bezier(.22,.72,.18,1) forwards}
@keyframes turnSpreadNext{0%{transform:rotateY(0deg)}48%{filter:brightness(.86)}100%{transform:rotateY(-180deg)}}
@keyframes turnSpreadPrev{0%{transform:rotateY(0deg)}48%{filter:brightness(.86)}100%{transform:rotateY(180deg)}}
.spread-book.stack-out-next{animation:stackOutNext 140ms ease forwards}.spread-book.stack-in-next{animation:stackInNext 220ms ease forwards}.spread-book.stack-out-prev{animation:stackOutPrev 140ms ease forwards}.spread-book.stack-in-prev{animation:stackInPrev 220ms ease forwards}
@keyframes stackOutNext{to{opacity:.2;transform:translateX(-14px)}}@keyframes stackInNext{from{opacity:.2;transform:translateX(14px)}to{opacity:1;transform:none}}@keyframes stackOutPrev{to{opacity:.2;transform:translateX(14px)}}@keyframes stackInPrev{from{opacity:.2;transform:translateX(-14px)}to{opacity:1;transform:none}}
.page-loading{position:absolute;z-index:12;inset:0;display:grid;place-content:center;text-align:center;border-radius:15px;background:rgba(6,20,32,.72);backdrop-filter:blur(4px)}.page-loading[hidden]{display:none}.page-loading span{width:38px;height:38px;margin:auto;border-radius:50%;border:3px solid rgba(255,255,255,.22);border-top-color:var(--gold-soft);animation:spin .7s linear infinite}.page-loading p{font-size:.8rem;color:#fff;margin:10px 0 0}@keyframes spin{to{transform:rotate(360deg)}}
.mobile-controls{display:none}
.reader-footer{position:sticky;bottom:0;z-index:45;height:var(--footer-h);flex-direction:column;justify-content:center;padding:9px clamp(18px,3vw,36px);background:rgba(5,18,29,.94);border-top:1px solid rgba(255,255,255,.08);backdrop-filter:blur(14px)}.footer-meta{display:flex;justify-content:space-between;font-size:.78rem;color:rgba(255,255,255,.78);margin-bottom:7px}.progress-track{position:relative;height:10px;border-radius:999px;background:rgba(255,255,255,.15);cursor:pointer;touch-action:none}.progress-fill{height:100%;width:0;border-radius:inherit;background:linear-gradient(90deg,#d39c3f,#f4daa0)}.progress-knob{position:absolute;left:0;top:50%;width:18px;height:18px;border-radius:50%;transform:translate(-50%,-50%);background:#e0ad51;border:2px solid #fff3d2;box-shadow:0 2px 8px rgba(0,0,0,.32)}.footer-hint{text-align:center;margin-top:6px;font-size:.66rem;color:rgba(255,255,255,.42)}
.toc-panel{position:fixed;z-index:80;top:0;left:0;width:min(430px,92vw);height:100vh;padding:24px;background:#0b1e2e;box-shadow:22px 0 70px rgba(0,0,0,.44);transform:translateX(-105%);transition:.28s ease;overflow:auto}.toc-panel.open{transform:none}.toc-head{display:flex;justify-content:space-between;align-items:center;padding-bottom:18px;border-bottom:1px solid rgba(255,255,255,.1)}.toc-head small{color:var(--gold-soft);text-transform:uppercase;letter-spacing:.12em;font-size:.68rem}.toc-head h2{font:700 2rem/1.2 Arial,"Arial Unicode MS","Segoe UI",Tahoma,sans-serif;margin:4px 0 0;color:#fff6df}.toc-list{display:grid}.toc-item{width:100%;display:grid;grid-template-columns:44px 1fr;gap:12px;text-align:left;padding:14px 4px;color:#fff;background:transparent;border-bottom:1px solid rgba(255,255,255,.08);cursor:pointer}.toc-item>span:first-child{color:var(--gold);font:700 .85rem/1.35 Arial,"Arial Unicode MS","Segoe UI",Tahoma,sans-serif}.toc-item strong{display:block;font-size:.9rem;line-height:1.35}.toc-item small{display:block;margin-top:4px;color:rgba(255,255,255,.45)}.toc-item:hover,.toc-item.active{color:var(--gold-soft)}.toc-note{color:rgba(255,255,255,.5);font-size:.78rem;line-height:1.6}.overlay{position:fixed;z-index:70;inset:0;background:rgba(0,0,0,.52);opacity:0;pointer-events:none;transition:.25s}.overlay.open{opacity:1;pointer-events:auto}
@media(max-width:1050px){.topbar{grid-template-columns:48px 1fr auto}.pill-link{padding:0 12px}.intro-section{grid-template-columns:1fr;padding-top:24px}.intro-visual{position:relative;top:auto;min-height:460px}.intro-visual img{width:min(70vw,430px)}.book-stamp{right:18%;bottom:4%}.intro-content{max-width:900px;margin:auto}.value-grid{grid-template-columns:1fr 1fr 1fr}}
@media(max-width:760px){:root{--bar-h:64px;--footer-h:70px}.topbar{height:var(--bar-h);grid-template-columns:44px 1fr auto;padding:0 10px;gap:8px}.brand strong{font-size:.85rem}.brand small{font-size:.62rem}.home-link,.download-link,body.reading .top-actions .intro-link,body.reading .top-actions .first-link{display:none!important}.icon-btn{width:38px;height:38px}.top-actions{gap:5px}.intro-section{width:min(100% - 24px,720px);padding:20px 0 46px;gap:18px}.intro-visual{min-height:340px}.intro-visual img{width:min(88vw,360px)}.book-stamp{width:86px;height:86px;right:3%;bottom:2%;border-width:4px}.book-stamp strong{font-size:1.5rem}.book-stamp span{font-size:.55rem}.intro-content h1{font-size:2.55rem}.intro-lead{font-size:1rem}.heart-note{padding:17px}.value-grid{grid-template-columns:1fr}.value-grid article{min-height:auto}.outcome-box{padding:18px}.intro-actions>*{width:100%}.reading .reader-section{padding:10px 9px 12px}.reader-toolbar{margin-bottom:8px}.nav-btn span{display:none}.nav-btn{min-width:42px;padding:0 14px;font-size:1.35rem}.reader-title span{max-width:210px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.page-stage{width:min(100%,560px);aspect-ratio:auto}.spread-book{position:relative;inset:auto;display:block}.spread-page{position:relative;top:auto;bottom:auto;left:auto;right:auto;width:100%;aspect-ratio:840/1191;border-radius:14px}.spread-left{display:block;border-radius:14px}.spread-right{display:none!important}.spread-left:after,.spread-right:after,.spread-gutter,.turn-sheet{display:none!important}.page-shadow{left:10%;right:10%;bottom:-10px}.mobile-controls{width:100%;display:grid;grid-template-columns:1fr auto 1fr;gap:8px;margin-top:10px}.mobile-controls button{min-height:42px;padding:0 10px;border-radius:12px;background:rgba(255,255,255,.07);color:#fff;border:1px solid var(--line);font-size:.76rem;font-weight:700}.reader-footer{height:var(--footer-h);padding:8px 14px}.footer-hint{display:none}}
@media(max-width:420px){.brand{justify-self:start}.text-icon#fullscreenBtn{display:none}.intro-content h1{font-size:2.2rem}.reader-title span{max-width:150px}.mobile-controls button{font-size:.69rem}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important}.ambient span,.intro-visual img{animation:none}.turn-sheet.turn-next,.turn-sheet.turn-prev{animation-duration:120ms}}

.intro-content h1,.intro-content h1 em,.heart-note span,.heart-note p,.value-grid h2,.value-grid p,.outcome-box h2,.outcome-box li,.outcome-box>p,.primary-btn,.ghost-btn,.pill-link,.download-link,.nav-btn,.toc-item,.reader-title{font-family:Arial,"Arial Unicode MS","Segoe UI",Tahoma,sans-serif!important}
.primary-btn,.ghost-btn,.pill-link,.download-link,.nav-btn{font-weight:700;line-height:1.4}
.heart-note p,.value-grid p,.outcome-box li,.performance-note{font-weight:400}