@property --ga{syntax:"<number>";inherits:false;initial-value:0}
:root{--font:"Be Vietnam Pro","Segoe UI","Helvetica Neue",Arial,"PingFang SC","Hiragino Sans GB","Noto Sans CJK SC","Microsoft YaHei","Noto Sans",sans-serif;--g:.25;--ink:#13304a;--mut:#465d70;--acc:#b85f0c;--acc2:#1b6680;--crgb:255,255,255;--lrgb:255,255,255;--glow:255,255,255;--shadow:0 10px 30px rgba(20,60,90,.12);--bg:url(bg_light.jpg);--bgc:#dfeef5;--red:#b3261e;--tsh:0 0 12px rgba(255,255,255,.55);
--ca:calc(.16 + .72*var(--g));--blur:calc(6px + 26px*var(--g));--card:rgba(var(--crgb),var(--ca));--glass:rgba(var(--crgb),calc(var(--ca)*.85));--line:rgba(var(--lrgb),calc(.35 + .45*var(--g)))}
[data-theme=dark]{--ink:#eef6fa;--mut:#b6cbd8;--acc:#f2b33d;--acc2:#8fd3ea;--crgb:10,28,46;--lrgb:255,255,255;--glow:160,220,255;--shadow:0 10px 30px rgba(0,0,0,.35);--bg:url(bg_deep.jpg);--bgc:#0c2a40;--red:#ff8a80;--tsh:0 0 12px rgba(0,10,25,.7);--line:rgba(var(--lrgb),calc(.10 + .2*var(--g)))}
@media(prefers-color-scheme:dark){:root:not([data-theme=light]){--ink:#eef6fa;--mut:#b6cbd8;--acc:#f2b33d;--acc2:#8fd3ea;--crgb:10,28,46;--lrgb:255,255,255;--glow:160,220,255;--shadow:0 10px 30px rgba(0,0,0,.35);--bg:url(bg_deep.jpg);--bgc:#0c2a40;--red:#ff8a80;--tsh:0 0 12px rgba(0,10,25,.7);--line:rgba(var(--lrgb),calc(.10 + .2*var(--g)))}}
*{box-sizing:border-box}html{-webkit-text-size-adjust:100%}
body{margin:0;font-family:var(--font);color:var(--ink);line-height:1.65;font-size:clamp(16px,.9rem + .25vw,19px);background:var(--bg) center/cover fixed,var(--bgc);min-height:100dvh}
a{color:var(--acc2)}
.glass,.card{background:var(--card);border:1px solid var(--line);backdrop-filter:blur(var(--blur)) saturate(1.4);-webkit-backdrop-filter:blur(var(--blur)) saturate(1.4);box-shadow:var(--shadow);border-radius:20px}
main .card,.tile,.side{text-shadow:var(--tsh)}
.draft-flag{position:fixed;right:10px;bottom:10px;z-index:60;font-size:12px;background:var(--red);color:#fff;padding:3px 10px;border-radius:99px;opacity:.85}
.top{position:sticky;top:0;z-index:40;display:flex;align-items:center;gap:8px;padding:8px 12px;margin:8px;border-radius:16px;padding-top:max(8px,env(safe-area-inset-top))}
.brand{font-weight:800;text-decoration:none;color:var(--ink);white-space:nowrap;font-size:1rem}.brand em{color:var(--acc);font-style:normal}
.ico{border:1px solid var(--line);background:var(--glass);color:var(--ink);border-radius:12px;min-width:40px;height:40px;font-size:18px;cursor:pointer}
.prog{flex:1;display:flex;align-items:center;gap:8px;min-width:60px}.bar{flex:1;height:8px;border-radius:9px;background:rgba(127,150,170,.3);overflow:hidden}.bar i{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--acc2),var(--acc));transition:width .4s}
#progTxt{font-size:.8rem;font-weight:700;min-width:3ch}
.side{position:fixed;z-index:50;top:64px;left:8px;bottom:8px;width:min(330px,86vw);overflow:auto;padding:12px;transform:translateX(-110%);transition:transform .25s}
body.nav-open .side{transform:none}
.side-h{font-weight:800;margin:4px 8px;color:var(--acc)}.side ol{list-style:none;margin:0;padding:0}
.side a{display:block;padding:7px 10px;border-radius:10px;text-decoration:none;color:var(--ink);font-size:.92rem;line-height:1.35}.side a span{display:block;color:var(--mut);font-size:.85em}
.side a.on{background:var(--glass);outline:1px solid var(--acc)}.side a.ok b::after,.tile.ok .st::after{content:" ✓";color:#2e9d5b}
main{max-width:min(980px,100%);margin:0 auto;padding:8px 12px 24px}
@media(min-width:1200px){body{padding-left:350px}.side{transform:none;top:72px}#menuBtn{display:none}main{max-width:1000px}}
@media(min-width:1700px){body{padding-left:380px}main{max-width:1180px}}
.card{padding:clamp(16px,3vw,34px);margin:14px 0}
h1{font-size:clamp(1.7rem,1.1rem + 2.6vw,3rem);line-height:1.2;margin:.1em 0 .3em;font-weight:800}
h2{font-size:clamp(1.25rem,1rem + 1vw,1.8rem);margin:0 0 .5em;line-height:1.3}h3{color:var(--acc2);margin:1.1em 0 .3em}
.eyebrow{text-transform:uppercase;letter-spacing:.14em;font-size:.78rem;font-weight:700;color:var(--acc);margin:0}
.hero.home{background:linear-gradient(135deg,rgba(19,72,104,.88),rgba(33,110,140,.75));color:#fff}.hero.home .sub{color:#f6c35a;font-size:1.15em}.hero.home a{color:#cfefff}.hero .meta{opacity:.8;font-size:.85em}
.chap h1{color:var(--ink)}.chap h1::after{content:"";display:block;width:80px;height:4px;background:var(--acc);border-radius:4px;margin-top:12px}
.btn{display:inline-block;padding:10px 20px;border-radius:12px;background:var(--acc);color:#fff!important;text-decoration:none;font-weight:700;margin:4px 6px 0 0}.btn.ghost{background:transparent;border:1px solid currentColor}
.tiles{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:12px}
.tile{display:block;padding:14px;text-decoration:none;color:var(--ink);border-radius:16px}.tile b{color:var(--acc)}.tile span{display:block;font-size:.92rem;line-height:1.4}
.k-goal{border-left:5px solid var(--acc2)}.k-mistake{border-left:5px solid var(--red)}.k-check{border-left:5px solid #2e9d5b}.k-summary{border-left:5px solid var(--acc)}.k-exercise{border-left:5px solid #7a5cc2}
.k-mistake h2::before{content:"⚠ "}.k-check h2::before{content:"☑ "}.k-summary h2::before{content:"★ "}.k-exercise h2::before{content:"✎ "}.k-goal h2::before{content:"◎ "}
blockquote{margin:1em 0;padding:.8em 1.2em;border-radius:14px;background:rgba(31,111,139,.12);border-left:4px solid var(--acc2)}
table{border-collapse:collapse;width:100%;font-size:.92em;display:block;overflow-x:auto}th,td{border:1px solid var(--line);padding:8px 10px;text-align:left;vertical-align:top}th{background:rgba(31,111,139,.18)}
li:has(>.chk){list-style:none;margin-left:-1.2em}.chk{display:flex;gap:10px;align-items:flex-start;cursor:pointer;padding:4px 0}.chk input,.done input{width:1.25em;height:1.25em;accent-color:#2e9d5b;margin-top:.25em;flex:none}
.chk input:checked+span{opacity:.6;text-decoration:line-through}
.done{display:flex;gap:10px;padding:14px 18px;font-weight:700;cursor:pointer}
.chkstat{color:var(--mut);font-size:.9em}
.pager{display:flex;justify-content:space-between;gap:10px;margin:18px 0}.pager a{padding:10px 16px;border-radius:12px;background:var(--card);border:1px solid var(--line);text-decoration:none;font-weight:700}
.foot{text-align:center;font-size:.85rem;color:var(--mut);padding:16px 12px 40px}.linkbtn{background:none;border:0;color:var(--red);cursor:pointer;text-decoration:underline;font:inherit}
.note{color:var(--mut);font-size:.9em}
.pres-ui{display:none}
/* ===== Trình chiếu: mỗi section = 1 slide, phủ kín mọi tỉ lệ màn (không viền đen) ===== */
body.present{padding:0;overflow:hidden;font-size:clamp(18px,min(2.15vw,3.6vh),64px)}
body.present .top,body.present .side,body.present .foot,body.present .pager,body.present .draft-flag{display:none}
body.present main{max-width:none;padding:0;margin:0}
body.present main>*{display:none}
body.present main>.cur{display:block;position:fixed;inset:0;margin:0;border-radius:0;border:0;padding:5vh 6vw 9vh;overflow:auto;background:transparent;box-shadow:none;backdrop-filter:none}
body.present main>.cur>*{max-width:min(92vw,170vh);margin-left:auto;margin-right:auto}
body.present h1{font-size:2.6em}body.present h2{font-size:1.7em}body.present .done{display:none}
body.present .hero.chap.cur{display:flex;flex-direction:column;justify-content:center}
body.present .hero.chap.cur h1{font-size:3em}
body.present .pres-ui{display:flex;position:fixed;right:2vw;bottom:2vh;gap:8px;align-items:center;z-index:70;font-size:16px;opacity:.35;transition:opacity .2s}
body.present .pres-ui:hover{opacity:1}.pres-ui button{width:40px;height:40px;border-radius:12px;border:1px solid var(--line);background:var(--card);color:var(--ink);font-size:20px;cursor:pointer}
/* ===== In ===== */
@media print{body{background:#fff!important;color:#000;padding:0!important;font-size:11pt}.top,.side,.pager,.pres-ui,.draft-flag,#resetBtn,.btn{display:none!important}
.card,.glass{background:#fff!important;box-shadow:none!important;backdrop-filter:none!important;border:1px solid #ccc;break-inside:avoid-page}.hero.home{color:#000}.hero.home .sub{color:#8a4b00}a{color:#000}main{max-width:none}section{break-inside:auto}}
@media(max-width:480px){.brand{font-size:.85rem}.brand em{display:none}}
body.present .eyebrow{font-size:.7em}body.present .chkstat{font-size:.7em}body.present main>.cur>*{width:100%}

/* ===== v2: cài đặt, ngôn ngữ, glow, cảm ứng ===== */
html{scroll-behavior:smooth;-webkit-tap-highlight-color:transparent}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important}}
.skip{position:absolute;left:-999px}.skip:focus{left:12px;top:12px;z-index:99;background:var(--acc);color:#fff;padding:8px 12px;border-radius:8px}
button,a,.chk,.done{touch-action:manipulation}
.ico{min-width:44px;height:44px;display:inline-flex;align-items:center;justify-content:center;gap:4px;text-decoration:none;padding:0 8px;flex:none}
.home-main span{font-size:.8rem;font-weight:700}
.langsw{display:flex;gap:2px;flex:none}.langsw a,.seg a{display:inline-flex;align-items:center;justify-content:center;min-width:40px;min-height:40px;padding:0 6px;border-radius:10px;text-decoration:none;color:var(--ink);font-size:.8rem;font-weight:700}
.langsw a.on,.seg a.on{background:var(--acc);color:#fff;text-shadow:none}
.setpanel{position:fixed;z-index:80;top:72px;right:10px;width:min(340px,calc(100vw - 20px));padding:14px 16px;border-radius:18px}
.setpanel[hidden]{display:none}.sp-h{font-weight:800;margin:10px 0 6px;font-size:.9rem;display:block}
.seg{display:flex;gap:6px;flex-wrap:wrap}.seg button{flex:1;min-height:44px;border-radius:12px;border:1px solid var(--line);background:var(--glass);color:var(--ink);font:inherit;font-size:.85rem;cursor:pointer}
.seg button[aria-checked=true]{background:var(--acc);color:#fff;border-color:transparent}
#glassR{width:100%;height:44px;accent-color:var(--acc)}
.tw{overflow-x:auto;-webkit-overflow-scrolling:touch;overscroll-behavior-x:contain;margin:0 0 1em}.tw table{display:table}
.side{-webkit-overflow-scrolling:touch;overscroll-behavior:contain}
.side a{min-height:44px}.chk{min-height:44px;align-items:center}.pager a{min-height:44px;display:inline-flex;align-items:center}
.btn{min-height:44px}.back-main{display:inline-block;margin-top:6px;padding:8px 4px;font-weight:700}
.chk input,.done input{width:1.4em;height:1.4em}
/* Glow theo con trỏ (chỉ bật qua class .glow-on khi có chuột & không giảm chuyển động) */
.glow-on :is(.card:not(.home),.tile,.btn,.ico,.pager a,.done){background-image:radial-gradient(var(--gr,260px) circle at var(--mx,50%) var(--my,50%),rgba(var(--glow),var(--ga,0)),transparent 70%);transition:--ga .2s}
.glow-on :is(.card:not(.home),.tile,.done){--gr:420px}
.glow-on :is(.card:not(.home),.tile,.btn,.ico,.pager a,.done):hover{--ga:.22}
[data-theme=dark].glow-on :is(.card,.tile,.btn,.ico,.pager a,.done):hover{--ga:.14}
@media(prefers-color-scheme:dark){html:not([data-theme=light]).glow-on :is(.card,.tile,.btn,.ico,.pager a,.done):hover{--ga:.14}}
.swipe-hint{position:fixed;top:50%;z-index:65;font-size:40px;opacity:0;pointer-events:none;color:var(--acc);transition:opacity .15s}
@media(max-width:720px){.home-main span{display:none}.prog{min-width:40px}#progTxt{display:none}.langsw{display:none}.top{gap:4px;padding:6px 8px}.ico{min-width:42px;padding:0 4px}}
@media(max-width:480px){.ico{min-width:40px;height:44px}}
@media print{.setpanel,.langsw,.home-main,.skip,.back-main{display:none!important}main .card,.tile{text-shadow:none}}
body.present main>.cur{text-shadow:none}
main .hero.home{text-shadow:0 1px 2px rgba(0,0,0,.35)}
@media(max-width:480px){#printBtn{display:none}.top{margin:6px}.brand{font-size:.8rem}.ico{min-width:40px}}

/* ===== v3: skip link, header pills, responsive header ===== */
.skip{position:fixed!important;left:12px;top:12px;z-index:100;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);clip-path:inset(50%);white-space:nowrap;border:0}
.skip:focus,.skip:focus-visible{width:auto;height:auto;margin:0;padding:8px 14px;clip:auto;clip-path:none;overflow:visible;background:var(--acc);color:#fff;border-radius:10px;text-decoration:none;font-weight:700;box-shadow:var(--shadow)}
.top{flex-wrap:nowrap;min-width:0}
.top>*{flex-shrink:0}.top .brand{flex-shrink:1;min-width:0;overflow:hidden;text-overflow:ellipsis}
.top .prog{flex:1 1 40px;min-width:40px}
.top a,.top a:hover,.top a:visited{text-decoration:none}
.langsw{display:flex;gap:6px;align-items:center;flex:none}
.langsw a,.seg a{display:inline-flex;align-items:center;justify-content:center;min-width:40px;height:36px;min-height:36px;padding:0 10px;border-radius:999px;border:1px solid var(--line);background:var(--glass);color:var(--ink);font-size:.78rem;font-weight:700;letter-spacing:.02em;text-decoration:none;line-height:1}
.seg a{height:44px;min-height:44px}
.langsw a:hover,.seg a:hover{border-color:var(--acc)}
.langsw a.on,.seg a.on{background:var(--acc);border-color:transparent;color:#fff;text-shadow:none}
.top .ico{border-radius:999px;height:40px;min-width:40px;padding:0 10px;gap:6px;border:1px solid var(--line);background:var(--glass);color:var(--ink);text-decoration:none;line-height:1}
.home-main span{font-size:.8rem;font-weight:700;white-space:nowrap}
.langsw a:focus-visible,.top .ico:focus-visible{outline:2px solid var(--acc);outline-offset:2px}
@media(max-width:1100px){.home-main span{display:none}}
@media(max-width:900px){#progTxt{display:none}.top{gap:6px}}
@media(max-width:720px){.langsw{display:none}.top{gap:4px;padding:6px 8px}.top .ico{min-width:40px;padding:0 6px}}
@media(max-width:480px){#printBtn{display:none}.top .prog{min-width:28px}}

/* ===== v4: mục lục thu gọn + nút chuyển chương ===== */
#menuBtn{display:inline-flex!important}
.side{transition:transform .25s,visibility .25s}
@media(min-width:1200px){body{transition:padding-left .25s}body.side-hidden{padding-left:0}body.side-hidden .side{transform:translateX(-110%);visibility:hidden}body.side-hidden main{max-width:1180px}}
@media(max-width:1199.98px){.side{visibility:hidden;z-index:75;top:8px}body.nav-open .side{visibility:visible;transform:none}
.side-back{position:fixed;inset:0;z-index:74;background:rgba(0,10,25,.35);-webkit-backdrop-filter:blur(2px);backdrop-filter:blur(2px)}.side-back[hidden]{display:none}body.nav-open{overflow:hidden}}
.chapnav a{position:fixed;top:50%;z-index:72;width:44px;height:64px;margin-top:-32px;display:flex;align-items:center;justify-content:center;border-radius:999px;border:1px solid var(--line);background:var(--glass);-webkit-backdrop-filter:blur(var(--blur));backdrop-filter:blur(var(--blur));color:var(--ink);font-size:30px;line-height:1;text-decoration:none;box-shadow:var(--shadow);opacity:.55;transition:opacity .2s}
.chapnav a:hover,.chapnav a:focus-visible{opacity:1;outline:2px solid var(--acc);outline-offset:2px}
.chapnav a[hidden]{display:none}
#chPrev{left:max(6px,env(safe-area-inset-left))}#chNext{right:max(6px,env(safe-area-inset-right))}
@media(min-width:1200px){body:not(.side-hidden):not(.present) #chPrev{left:352px}}
@media(min-width:1700px){body:not(.side-hidden):not(.present) #chPrev{left:382px}}
@media(max-width:720px){.chapnav a{top:auto;bottom:max(46px,calc(env(safe-area-inset-bottom) + 40px));margin-top:0;width:44px;height:44px;font-size:26px}}
body.present .chapnav a{opacity:.35}body.present .chapnav a:hover{opacity:1}
@media print{.chapnav,.side-back{display:none!important}}

/* ===== v5: footer trải full chiều ngang, nội dung căn giữa trang ===== */
:root{--padl:0px}
@media(min-width:1200px){:root{--padl:350px}body.side-hidden{--padl:0px}}
@media(min-width:1700px){:root{--padl:380px}body.side-hidden{--padl:0px}}
.foot{position:relative;z-index:55;box-sizing:border-box;margin:24px 0 0 calc(-1 * var(--padl));width:calc(100% + var(--padl));padding:18px 16px max(48px,calc(env(safe-area-inset-bottom) + 40px));background:var(--glass);border-top:1px solid var(--line);-webkit-backdrop-filter:blur(var(--blur));backdrop-filter:blur(var(--blur))}
.foot-in{max-width:1180px;margin:0 auto;text-align:center;overflow-wrap:anywhere}
/* v5: header luôn trải full viewport, sidebar nằm dưới header */
.top{margin-left:calc(8px - var(--padl));margin-right:8px;z-index:60}
html{scroll-padding-top:84px}main section,main h2,main h3,[id]{scroll-margin-top:84px}
main{padding-top:12px}
/* build 1792829277 */