/* Victor Hoang AI · trang chủ bản 2 · theo bộ nhận diện 2.3 (Đêm ấm) */
:root{
  --nen:#100E0C; --nen2:#171310; --the:#1D1814;
  --vach:rgba(245,240,232,.12); --vach-dam:rgba(243,237,226,.28);
  --chu:#F5F0E8; --phu:#ADA396; --nhan:#DE7C56; --glow:222,124,86;
  --kem:#F4EFE6; --chu-kem:#1B1714; --nhan-kem:#A84A27; /* #A84A27: 4,99:1 trên nền kem (bản nhận diện ghi #B4532F, 4,35:1, chưa đạt) */
  --serif:'Crimson Pro',Georgia,'Times New Roman',serif;
  --sans:'Be Vietnam Pro',system-ui,-apple-system,'Segoe UI',sans-serif;
  --le:clamp(16px,5vw,72px);
  --rong:1184px;
  --muc:clamp(72px,8.4vw,128px);
  --bo:20px;
  --em-ra:cubic-bezier(.23,1,.32,1);
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:88px}
body{margin:0;background:var(--nen);color:var(--chu);font-family:var(--sans);font-size:17px;line-height:1.65;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;overflow-x:hidden}
h1,h2,h3,p,ul,ol,figure,blockquote{margin:0;padding:0}
ul,ol{list-style:none}
img,svg{display:block;max-width:100%}
img{height:auto}
picture{display:contents}
a{color:inherit;text-decoration:none}
button{font:inherit;color:inherit}
::selection{background:rgba(var(--glow),.38);color:var(--chu)}
:focus-visible{outline:2px solid var(--nhan);outline-offset:3px;border-radius:6px}
.bo-qua{position:absolute;left:16px;top:-80px;z-index:100;background:var(--chu);color:var(--nen);padding:12px 18px;border-radius:12px;font-weight:600}
.bo-qua:focus{top:12px}

/* hạt nhiễu rất nhẹ, cho nền tối khỏi bệt */
body::after{content:"";position:fixed;inset:0;z-index:60;pointer-events:none;opacity:.055;mix-blend-mode:overlay;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='180'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix values='0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 .9 0'/%3E%3C/filter%3E%3Crect width='180' height='180' filter='url(%23n)'/%3E%3C/svg%3E")}

.khung{width:100%;max-width:calc(var(--rong) + 2*var(--le));margin-inline:auto;padding-inline:var(--le)}

/* chữ */
.tit{font-family:var(--serif);font-weight:600;letter-spacing:-.015em;line-height:1.04;text-wrap:balance}
em,.tit em{font-family:var(--serif);font-style:italic;font-weight:500;color:var(--nhan)}
.tit em{white-space:nowrap}
.nhan-nho{font-family:var(--sans);font-size:13px;font-weight:600;letter-spacing:.16em;text-transform:uppercase;color:var(--phu);line-height:1.4}
.nhan-nho.vach{display:flex;align-items:center;gap:12px}
.nhan-nho.vach::before{content:"";flex:none;width:24px;height:1.5px;border-radius:1px;background:var(--nhan)}
h2.tit{font-size:clamp(2.2rem,4.3vw,3.5rem);line-height:1.08}
h3.tit{font-size:clamp(1.4rem,2vw,1.7rem);line-height:1.16}

/* nút */
.nut{display:inline-flex;align-items:center;justify-content:center;gap:10px;height:54px;padding:0 26px;border-radius:14px;font-weight:600;font-size:17px;line-height:1;background:var(--chu);color:var(--nen);border:1px solid transparent;white-space:nowrap;cursor:pointer;transition:transform .16s var(--em-ra),background-color .16s ease-out,border-color .16s ease-out}
.nut.phu{background:transparent;color:var(--chu);border-color:var(--vach-dam)}
.nut.nho{height:44px;padding:0 20px;font-size:15px;border-radius:12px}
.nut:active{transform:scale(.97)}
@media (hover:hover) and (pointer:fine){
  .nut:hover{background:#fff}
  .nut.phu:hover{background:rgba(245,240,232,.06);border-color:rgba(243,237,226,.5)}
}

/* ---------- thanh trên ---------- */
.dau{position:sticky;top:0;z-index:50;border-bottom:1px solid transparent;transition:background-color .25s ease-out,border-color .25s ease-out}
.dau.cuon{background:rgba(16,14,12,.84);-webkit-backdrop-filter:blur(14px) saturate(1.2);backdrop-filter:blur(14px) saturate(1.2);border-bottom-color:var(--vach)}
.dau .khung{display:flex;align-items:center;justify-content:space-between;height:84px;gap:16px}
.ky{display:inline-flex;align-items:center;gap:12px;min-height:44px;font-weight:700;font-size:20px;letter-spacing:-.005em;white-space:nowrap;line-height:1}
.ky svg{width:40px;height:40px;flex:none}
.ky em{font-size:1.2em;margin-left:.12em}
.loi{display:flex;align-items:center;gap:34px;font-size:15.5px;font-weight:500;color:var(--phu)}
.loi>a:not(.nut){padding:10px 0;transition:color .15s ease-out}
.loi>a:not(.nut):hover{color:var(--chu)}
.menu{display:none}

/* ---------- màn đầu ---------- */
.man-dau{position:relative;margin-top:-84px;padding-top:84px;overflow:hidden}
.quang{position:absolute;right:-180px;top:-300px;width:980px;height:980px;border-radius:50%;background:radial-gradient(circle,rgba(var(--glow),.22),rgba(var(--glow),0) 62%);pointer-events:none}
.man-dau .khung{position:relative;display:grid;grid-template-columns:1.2fr 1fr;gap:56px;align-items:start;padding-top:clamp(48px,6vw,84px);padding-bottom:clamp(56px,6vw,84px)}
.man-dau h1{font-size:clamp(2.3rem,4.5vw,3.625rem);margin-top:22px;white-space:nowrap;text-wrap:initial}
.man-dau h1 span{display:block}
.mo-dau{color:var(--phu);font-size:19px;line-height:1.6;margin-top:26px;max-width:520px;text-wrap:pretty}
.hang-nut{display:flex;flex-wrap:wrap;gap:14px;margin-top:34px}
.ba-so{display:flex;gap:54px;border-top:1px solid var(--vach);margin-top:46px;padding-top:28px}
.so{font-family:var(--serif);font-weight:600;color:var(--nhan);font-size:54px;line-height:1;font-variant-numeric:lining-nums}
.ba-so li{display:flex;flex-direction:column}
.ba-so span{margin-top:8px;color:var(--phu);font-size:14px;line-height:1.4}

.canh-anh{position:relative;width:100%;max-width:430px;margin-left:auto}
.chan-dung{position:relative;aspect-ratio:430/540;border-radius:22px;overflow:hidden;border:1px solid var(--vach);background:var(--nen2);box-shadow:0 40px 90px -30px rgba(0,0,0,.7)}
.chan-dung img{width:100%;height:100%;object-fit:cover;object-position:50% 10%;filter:saturate(.96) brightness(.9) contrast(1.05)}
.chan-dung::after{content:"";position:absolute;inset:0;background:linear-gradient(180deg,rgba(15,13,11,.10) 0%,rgba(15,13,11,0) 40%,rgba(15,13,11,.94) 100%),radial-gradient(circle at 85% 0%,rgba(var(--glow),.22),rgba(var(--glow),0) 55%)}
.chan-dung figcaption{position:absolute;z-index:1;left:6%;right:6%;bottom:5%}
.chan-dung b{display:block;font-weight:700;font-size:22px;line-height:1.3}
.chan-dung figcaption span{display:block;color:#CFC7BA;font-size:15px;line-height:1.45;margin-top:3px;text-wrap:balance}
/* thẻ video nổi: bản duyệt thò ra trái 125px so với mép ảnh, ngang hàng dải số */
.video-nho{position:absolute;z-index:2;left:-125px;bottom:21%;width:300px;display:flex;gap:12px;align-items:center;background:var(--the);border:1px solid var(--vach);border-radius:16px;padding:12px;box-shadow:0 24px 60px rgba(0,0,0,.55),inset 0 1px 0 rgba(245,240,232,.06);transition:transform .25s var(--em-ra),border-color .2s ease-out}
.video-nho .khung-nho{position:relative;flex:none;width:116px;aspect-ratio:16/9;border-radius:10px;border:1px solid var(--vach);background:var(--nen);display:grid;place-items:center}
.video-nho .tit{display:block;font-size:16px;line-height:1.18;margin-top:4px;text-wrap:initial}
.video-nho .nhan-nho{display:block;font-size:11px;letter-spacing:.14em}
.choi{width:26px;height:26px;border-radius:50%;background:var(--chu);display:grid;place-items:center;transition:background-color .2s ease-out,transform .25s var(--em-ra)}
.choi::after{content:"";border-left:9px solid var(--nen);border-top:6px solid transparent;border-bottom:6px solid transparent;margin-left:3px;transition:border-left-color .2s ease-out}
@media (hover:hover) and (pointer:fine){
  .video-nho:hover{transform:translateY(-3px);border-color:var(--vach-dam)}
  .video-nho:hover .choi{transform:scale(1.08)}
}

/* chuyển động vào màn đầu: chữ trượt lên 12px, ảnh hiện sau một nhịp */
@keyframes len{from{opacity:0;transform:translateY(12px)}}
@keyframes hien-anh{from{opacity:0;transform:translateY(16px) scale(.985)}}
.dau-chu>*{animation:len .8s var(--em-ra) backwards}
.dau-chu>:nth-child(2){animation-delay:60ms}
.dau-chu>:nth-child(3){animation-delay:120ms}
.dau-chu>:nth-child(4){animation-delay:180ms}
.dau-chu>:nth-child(5){animation-delay:240ms}
.chan-dung{animation:hien-anh 1s var(--em-ra) 120ms backwards}
.video-nho{animation:len .8s var(--em-ra) 480ms backwards}

/* ---------- mục chung ---------- */
.muc{padding-block:var(--muc);position:relative}
.muc.sat{padding-top:clamp(28px,3.4vw,48px)}
.muc.vach-tren::before{content:"";position:absolute;top:0;left:max(var(--le),calc((100% - var(--rong))/2));right:max(var(--le),calc((100% - var(--rong))/2));height:1px;background:var(--vach)}
.dau-muc{display:flex;align-items:flex-end;justify-content:space-between;gap:32px;margin-bottom:clamp(32px,4vw,56px)}
.dau-muc>p{max-width:400px;color:var(--phu);font-size:16px;line-height:1.6;text-wrap:pretty}
.nhan-nho + .tit{margin-top:16px}

/* ---------- video ---------- */
.luoi-video{display:grid;grid-template-columns:repeat(4,1fr);column-gap:clamp(14px,2vw,24px)}
.vid{display:block}
.vid-bia{position:relative;aspect-ratio:9/16;border-radius:var(--bo);overflow:hidden;border:1px solid var(--vach);background:var(--nen);container-type:inline-size;transition:border-color .2s ease-out}
.vid-bia img{width:100%;height:100%;object-fit:cover;transition:transform .6s var(--em-ra)}
/* tít nằm sẵn trong ảnh bìa; nút xem ở góc phải dưới, ngang hàng ảnh nhỏ của anh; độ dài ở góc phải trên, ngang hàng nhãn */
.vid-bia .choi{position:absolute;z-index:1;right:8.1%;top:91.1%;width:40px;height:40px;width:clamp(30px,14cqw,42px);height:clamp(30px,14cqw,42px);margin-top:-20px;margin-top:calc(clamp(30px,14cqw,42px)/-2);background:transparent;box-shadow:inset 0 0 0 1.5px rgba(245,240,232,.75)}
.vid-bia .choi::after{border-left:11px solid var(--chu);border-top:7px solid transparent;border-bottom:7px solid transparent}
.vid-dai{position:absolute;z-index:1;right:8.1%;top:6.25%;transform:translateY(-50%);font-size:13px;font-size:clamp(12.5px,4.8cqw,14px);font-weight:600;line-height:1;color:var(--chu);font-variant-numeric:tabular-nums}
.vid .nhan-nho{display:block;margin-top:18px}
.vid p{margin-top:8px;color:var(--chu);font-size:16px;line-height:1.55;text-wrap:pretty}
.an-doc{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);clip-path:inset(50%)}
@supports (grid-template-rows:subgrid){
  /* bốn thẻ chung hàng: bìa, nhãn, mô tả thẳng nhau */
  .luoi-video>li{grid-row:span 3;display:grid;grid-template-rows:subgrid}
  .vid{grid-row:1/-1;display:grid;grid-template-rows:subgrid;position:relative}
}
@media (hover:hover) and (pointer:fine){
  .vid:hover .vid-bia{border-color:var(--vach-dam)}
  .vid:hover .vid-bia img{transform:scale(1.03)}
  .vid:hover .choi{background:var(--chu);box-shadow:none}
  .vid:hover .choi::after{border-left-color:var(--nen)}
}

/* ---------- đội AI ---------- */
.doi{background:var(--nen2);border-block:1px solid var(--vach)}
.doi-luoi{display:grid;grid-template-columns:1fr 1fr;gap:clamp(40px,6vw,96px);align-items:center}
.doan{margin-top:22px;color:var(--phu);max-width:500px;text-wrap:pretty}
.phong{margin-top:32px;border-top:1px solid var(--vach)}
.phong li{display:grid;grid-template-columns:132px 1fr;gap:16px;padding:15px 0;border-bottom:1px solid var(--vach);align-items:baseline}
.phong b{font-weight:600;font-size:16.5px}
.phong span{color:var(--phu);font-size:16px}
.doan.ghi{margin-top:26px;color:var(--chu)}
/* sơ đồ: nét mảnh, phẳng, một ô màu nhấn duy nhất */
.so-do{background:var(--nen);border:1px solid var(--vach);border-radius:22px;padding:clamp(24px,3.4vw,44px) clamp(12px,3vw,40px) clamp(18px,2.4vw,28px)}
.so-do svg{width:100%;max-width:400px;height:auto;margin-inline:auto;overflow:visible}
.so-do figcaption{margin-top:clamp(18px,2.4vw,28px);padding-top:16px;border-top:1px solid var(--vach);color:var(--phu);font-size:14.5px;line-height:1.55;text-align:center;text-wrap:balance}
.sd-o{fill:none;stroke:rgba(245,240,232,.5);stroke-width:1.2}
.sd-net{fill:none;stroke:rgba(245,240,232,.86);stroke-width:1.9;stroke-linecap:round;stroke-linejoin:round}
.sd-o.sd-cam,.sd-net.sd-cam{stroke:var(--nhan)}
.sd-day{fill:none;stroke:rgba(245,240,232,.3);stroke-width:1.2;stroke-linecap:round;stroke-linejoin:round}
.sd-ten{font-family:var(--sans);font-weight:600;font-size:15px;fill:var(--chu)}
.sd-viec{font-family:var(--sans);font-weight:400;font-size:13.5px;fill:var(--phu)}

.luat{display:grid;grid-template-columns:1fr 1.25fr;gap:clamp(32px,6vw,96px);margin-top:clamp(56px,7vw,96px);padding-top:clamp(48px,6vw,80px);border-top:1px solid var(--vach);align-items:start}
.luat-dau{position:sticky;top:120px}
.luat .so{font-size:clamp(5.5rem,10vw,8.5rem);line-height:.82;display:block;margin-left:-.05em}
.luat h3{margin-top:22px;font-size:clamp(1.9rem,3vw,2.6rem);line-height:1.1}
.luat-dau p{margin-top:16px;color:var(--phu);font-size:16px;max-width:360px;text-wrap:pretty}
.luat ol{border-top:1px solid var(--vach)}
.luat li{display:grid;grid-template-columns:84px 1fr;column-gap:16px;padding:20px 0 21px;border-bottom:1px solid var(--vach);align-items:baseline}
.luat li i{grid-row:span 2;font-family:var(--serif);font-style:italic;font-weight:500;font-size:19px;color:var(--nhan);line-height:1.4}
.luat li b{display:block;font-weight:600;font-size:18px;line-height:1.4}
.luat li span{display:block;margin-top:5px;color:var(--phu);font-size:16px;line-height:1.6}

/* ---------- về mình ---------- */
.ve-luoi{display:grid;grid-template-columns:5fr 6fr;gap:clamp(40px,7vw,112px);align-items:center}
.ve-anh{position:relative;max-width:470px}
.ve-anh::before{content:"";position:absolute;inset:18px -18px -18px 18px;border:1px solid var(--vach);border-radius:22px}
.ve-anh img{position:relative;width:100%;aspect-ratio:4/5;object-fit:cover;object-position:50% 22%;border-radius:22px;border:1px solid var(--vach);filter:saturate(.96) brightness(.92) contrast(1.04)}
.ve-chu p:not(.nhan-nho){margin-top:20px;color:var(--phu);font-size:18px;line-height:1.7;max-width:540px;text-wrap:pretty}
.ve-chu h2 + p:not(.nhan-nho){margin-top:28px;color:var(--chu)}

/* ---------- bài viết ---------- */
.bai-chinh{display:grid;grid-template-columns:1.15fr 1fr;gap:clamp(24px,4vw,64px);align-items:center;background:var(--kem);color:var(--chu-kem);border-radius:22px;padding:clamp(26px,4vw,56px);box-shadow:0 24px 50px -30px rgba(0,0,0,.6);transition:transform .25s var(--em-ra)}
.bai-trai{display:flex;flex-direction:column;align-items:flex-start}
.bai-chinh .nhan-nho{color:#6B6157}
.bai-chinh h3{margin-top:16px;font-size:clamp(1.8rem,3vw,2.6rem);line-height:1.1}
.bai-chinh em{color:var(--nhan-kem)}
.bai-chinh p{margin-top:16px;color:#4D453D;max-width:520px}
.cau-mau{padding:22px 24px 24px;border:1px solid rgba(27,23,20,.16);border-radius:16px;font-family:var(--serif);font-size:clamp(20px,1.9vw,24px);line-height:1.45;color:var(--chu-kem);background:rgba(255,255,255,.42)}
.cau-mau .nhan-nho{display:block;margin-bottom:12px}
.cau-mau i{font-style:italic;color:var(--nhan-kem)}
.doc-bai{margin-top:28px;display:inline-flex;align-items:center;gap:10px;min-height:44px;font-weight:600;font-size:17px;border-bottom:1.5px solid rgba(27,23,20,.3);transition:border-color .2s ease-out}
.doc-bai svg{width:20px;height:20px;transition:transform .2s var(--em-ra)}
@media (hover:hover) and (pointer:fine){
  .bai-chinh:hover{transform:translateY(-4px)}
  .bai-chinh:hover .doc-bai{border-bottom-color:var(--chu-kem)}
  .bai-chinh:hover .doc-bai svg{transform:translateX(4px)}
}

/* ---------- thư tin: một dải mỏng, không ảnh ---------- */
.thu{padding-top:0}
.thu-the{position:relative;overflow:hidden;display:flex;align-items:center;justify-content:space-between;gap:24px 48px;border:1px solid var(--vach);border-radius:22px;background:var(--nen2);padding:clamp(24px,3.6vw,44px) clamp(22px,4vw,52px)}
.thu-the::before{content:"";position:absolute;right:-160px;top:-260px;width:620px;height:620px;border-radius:50%;background:radial-gradient(circle,rgba(var(--glow),.2),rgba(var(--glow),0) 62%);pointer-events:none}
.thu-chu{position:relative}
.thu-chu h2{font-size:clamp(1.8rem,3vw,2.4rem)}
.thu-chu p:not(.nhan-nho){margin-top:12px;color:var(--phu);max-width:560px;text-wrap:pretty}
.thu-the .nut{position:relative;flex:none}

/* ---------- chân trang ---------- */
.chan{border-top:1px solid var(--vach);padding-block:clamp(56px,7vw,96px) 40px}
.chan-tren{display:flex;justify-content:space-between;align-items:flex-end;gap:40px;flex-wrap:wrap}
.chan .khau{font-size:clamp(2.6rem,6.4vw,5rem);margin-top:22px}
.chan nav ul{display:flex;gap:28px;flex-wrap:wrap;color:var(--phu);font-size:15.5px;font-weight:500}
.chan nav a{display:inline-flex;align-items:center;min-height:44px}
.chan nav a:hover{color:var(--chu)}
.chan-duoi span{text-wrap:balance}
.chan-duoi{display:flex;justify-content:space-between;gap:12px 32px;flex-wrap:wrap;margin-top:clamp(40px,5vw,64px);padding-top:24px;border-top:1px solid var(--vach);color:var(--phu);font-size:14px}

/* ---------- hiện dần khi cuộn (chỉ khi có JavaScript) ---------- */
.js .hien{opacity:0;transform:translateY(14px);transition:opacity .7s ease-out,transform .8s var(--em-ra);transition-delay:var(--tre,0ms)}
.js .hien.vao{opacity:1;transform:none}
/* ---------- 1199 trở xuống: thẻ nổi thò ít lại cho khỏi đè chữ ---------- */
@media (max-width:1199px){
  .man-dau .khung{gap:40px}
  .video-nho{left:-64px}
  .ba-so{gap:40px}
}
@media (max-width:1100px){
  .loi{gap:26px}
  .video-nho{left:-56px}
}
/* ---------- máy tính bảng và điện thoại ---------- */
@media (max-width:900px){
  body{font-size:16.5px}
  html{scroll-padding-top:80px}
  .loi>a:not(.nut){display:none}
  .dau .khung{height:72px;gap:10px}
  .man-dau{margin-top:-72px;padding-top:72px}
  .ky{font-size:17px;gap:10px}
  .ky svg{width:34px;height:34px}
  .loi{gap:8px}
  .loi .nut{height:44px;padding:0 14px;font-size:14px;border-radius:12px}
  .menu{display:block;position:relative}
  .menu summary{list-style:none;width:44px;height:44px;border-radius:12px;border:1px solid var(--vach-dam);display:grid;place-items:center;cursor:pointer}
  .menu summary::-webkit-details-marker{display:none}
  .menu summary svg{width:20px;height:20px;stroke:var(--chu);fill:none;stroke-width:1.6;stroke-linecap:round}
  .menu ul{position:absolute;right:0;top:54px;min-width:248px;background:var(--the);border:1px solid var(--vach);border-radius:16px;padding:8px;box-shadow:0 24px 60px rgba(0,0,0,.6)}
  .menu li a{display:flex;align-items:center;min-height:48px;padding:0 14px;border-radius:10px;color:var(--chu);font-size:16.5px;font-weight:500}
  .menu li a:active{background:rgba(245,240,232,.06)}
  .menu li.tach{border-top:1px solid var(--vach);margin-top:6px;padding-top:6px}
  .menu li.tach a{font-weight:600}
  .quang{right:-160px;top:-170px;width:520px;height:520px;background:radial-gradient(circle,rgba(var(--glow),.26),rgba(var(--glow),0) 64%)}
  .man-dau .khung{grid-template-columns:1fr;gap:30px;padding-top:34px;padding-bottom:56px}
  .man-dau h1{font-size:min(9.5vw,3.4rem);margin-top:16px}
  .nhan-nho{letter-spacing:.14em}
  .mo-dau{font-size:16.5px;margin-top:18px}
  .hang-nut{gap:10px;margin-top:24px}
  .hang-nut .nut{height:50px;font-size:15.5px;padding:0 18px;flex:1 1 0}
  .ba-so{gap:16px;margin-top:30px;padding-top:22px;justify-content:space-between}
  .so{font-size:38px}
  .ba-so span{font-size:14px;margin-top:6px}
  .canh-anh{max-width:520px;margin-inline:auto}
  .chan-dung{aspect-ratio:346/400}
  .chan-dung b{font-size:18px}
  .chan-dung figcaption span{font-size:14px}
  .video-nho{position:relative;left:auto;bottom:auto;width:100%;margin-top:12px}
  .video-nho .tit{font-size:18px}
  .video-nho .nhan-nho{font-size:12.5px}
  .dau-muc{display:block}
  .dau-muc>p{margin-top:16px;max-width:none}
  .luoi-video{grid-template-columns:repeat(4,1fr);column-gap:12px}
  .vid .nhan-nho{font-size:12.5px;letter-spacing:.1em;margin-top:14px}
  .vid p{font-size:15px;line-height:1.5}
  .doi-luoi,.luat,.ve-luoi{grid-template-columns:1fr}
  .phong li{grid-template-columns:112px 1fr}
  .so-do svg{max-width:360px}
  .luat-dau{position:static}
  .luat li{grid-template-columns:72px 1fr}
  .ve-anh{margin-right:18px}
  .ve-chu p:not(.nhan-nho){font-size:17px}
  .bai-chinh{grid-template-columns:1fr}
  .thu-the{display:block}
  .thu-the .nut{width:100%;margin-top:24px}
  .chan-tren{display:block}
  .chan nav{margin-top:24px}
  .chan nav ul{display:grid;grid-template-columns:repeat(3,auto);justify-content:start;gap:0 28px}
}
@media (max-width:599px){
  .luoi-video{grid-template-columns:1fr 1fr;column-gap:14px}
  .luoi-video>li{padding-bottom:36px}
  .luoi-video>li:nth-last-child(-n+2){padding-bottom:0}
  .vid .nhan-nho{letter-spacing:.05em}
}
@media (max-width:420px){
  .ky{font-size:16px;gap:8px}
  .ky svg{width:32px;height:32px}
  .chu-rong{display:none}
  .ba-so{gap:12px}
  .phong li{grid-template-columns:100px 1fr;gap:12px}
  .luat li{grid-template-columns:1fr}
  .luat li i{grid-row:auto}
}
@media (max-width:349px){
  /* máy rất hẹp: nút Theo dõi dời vào menu (mục cuối của menu) */
  .loi>.nut{display:none}
}

/* =====================================================
   TRANG ĐỌC · nền kem
   ===================================================== */
body.kem{background:var(--kem);color:var(--chu-kem);font-size:19px;line-height:1.7}
body.kem::after{opacity:.035;mix-blend-mode:multiply}
body.kem ::selection{background:rgba(168,74,39,.22);color:var(--chu-kem)}
body.kem :focus-visible{outline-color:var(--nhan-kem)}
.kem em{color:var(--nhan-kem)}
.kem .nhan-nho{color:#6B6157}
.kem .dau.cuon{background:rgba(244,239,230,.88);border-bottom-color:rgba(27,23,20,.12)}
.kem .loi{color:#5A5148}
.kem .loi>a:not(.nut):hover{color:var(--chu-kem)}
.kem .nut{background:var(--chu-kem);color:var(--kem)}
@media (hover:hover) and (pointer:fine){.kem .nut:hover{background:#000}}
.cot{width:100%;max-width:calc(680px + 2*var(--le));margin-inline:auto;padding-inline:var(--le)}
.bai-dau{padding-top:clamp(28px,5vw,72px)}
.bai-dau>*{animation:len .8s var(--em-ra) backwards}
.bai-dau>:nth-child(3){animation-delay:60ms}
.bai-dau>:nth-child(4){animation-delay:120ms}
.bai-dau>:nth-child(5){animation-delay:180ms}
.ve-truoc{display:inline-flex;align-items:center;gap:8px;min-height:48px;font-size:15px;font-weight:600;color:#5A5148}
.ve-truoc svg{width:18px;height:18px}
.ve-truoc:hover{color:var(--chu-kem)}
.bai-dau .nhan-nho{display:block;margin-top:18px}
.bai-dau h1{font-size:clamp(2.35rem,5.6vw,3.7rem);line-height:1.07;margin-top:18px}
.bai-dau .dan{margin-top:26px;font-size:clamp(1.2rem,2vw,1.38rem);line-height:1.6;color:#3B342E;text-wrap:pretty}
.tac-gia{display:flex;align-items:center;gap:14px;margin-top:34px;padding-block:20px;border-block:1px solid rgba(27,23,20,.14);font-size:15px;line-height:1.45;color:#5A5148}
.tac-gia img{width:48px;height:48px;border-radius:50%;object-fit:cover;flex:none}
.tac-gia b{display:block;color:var(--chu-kem);font-size:16px;font-weight:600}
.bai-anh{margin-top:clamp(28px,4vw,40px)}
.bai-anh img{width:100%;aspect-ratio:3/2;object-fit:cover;object-position:50% 30%;border-radius:22px;animation:hien-anh 1s var(--em-ra) 200ms backwards}
.than{padding-block:clamp(32px,5vw,52px) clamp(64px,8vw,104px)}
.than p{margin-top:18px;text-wrap:pretty}
.than>p:first-child{margin-top:0}
.than h2.tit{margin-top:clamp(52px,7vw,80px);font-size:clamp(1.9rem,3.6vw,2.5rem)}
.nam-dieu{margin-top:26px;border-top:1px solid rgba(27,23,20,.14)}
.nam-dieu li{display:grid;grid-template-columns:64px 1fr;column-gap:20px;align-items:baseline;padding:20px 0 22px;border-bottom:1px solid rgba(27,23,20,.14)}
.nam-dieu .so{color:var(--nhan-kem);font-size:56px;line-height:.9}
.nam-dieu h3{font-family:var(--serif);font-weight:600;font-size:clamp(1.55rem,3vw,1.9rem);line-height:1.2;letter-spacing:-.012em}
.nam-dieu p{margin-top:6px;color:#3B342E}
.nam-dieu .nam{border-bottom-color:var(--nhan-kem)}
.ghi-chu{margin-top:clamp(36px,5vw,48px);padding:24px 26px;border-radius:18px;background:#EAE3D6;font-size:17.5px}
.ghi-chu .nhan-nho{display:block}
.ghi-chu p{margin-top:10px}
.o-chep{margin-top:26px;border-radius:18px;background:var(--chu-kem);color:var(--kem);overflow:hidden;box-shadow:0 30px 60px -34px rgba(27,23,20,.6)}
.o-chep-dau{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:10px 10px 10px 22px;border-bottom:1px solid rgba(245,240,232,.12)}
.o-chep-dau>span{font-size:13px;font-weight:600;letter-spacing:.14em;text-transform:uppercase;color:#ADA396}
.o-chep button{height:48px;min-width:104px;padding:0 18px;border-radius:11px;border:1px solid rgba(243,237,226,.28);background:transparent;color:var(--kem);font-size:15px;font-weight:600;cursor:pointer;transition:background-color .15s ease-out,transform .15s var(--em-ra)}
.o-chep button:hover{background:rgba(245,240,232,.08)}
.o-chep button:active{transform:scale(.97)}
.o-chep pre{margin:0;padding:22px;font-family:var(--serif);font-size:22px;line-height:1.5;white-space:pre-wrap;overflow-wrap:anywhere}
.o-chep pre i{font-style:italic;color:var(--nhan)}
html:not(.js) .o-chep button{display:none}
.nguon{margin-top:clamp(40px,5vw,56px);padding-top:22px;border-top:1px solid rgba(27,23,20,.14);font-size:16px;line-height:1.6;color:#4D453D}
.nguon ul{margin-top:12px}
.nguon li{position:relative;padding-left:20px;margin-top:8px}
.nguon li::before{content:"";position:absolute;left:0;top:.72em;width:10px;height:1.5px;background:var(--nhan-kem)}
.xem-video{margin-top:clamp(40px,5vw,56px);display:flex;align-items:center;gap:20px;padding:14px;border:1px solid rgba(27,23,20,.16);border-radius:18px;transition:border-color .2s ease-out}
.xem-video:hover{border-color:rgba(27,23,20,.4)}
.xem-video img{width:96px;aspect-ratio:9/16;object-fit:cover;border-radius:10px;flex:none}
.xem-video .tit{display:block;font-size:22px;line-height:1.18;margin-top:6px}
.xem-video span.phu-kem{display:block;margin-top:6px;font-size:15px;color:#5A5148}
.kem .chan{border-top-color:rgba(27,23,20,.14)}
.kem .chan nav ul,.kem .chan-duoi{color:#5A5148}
.kem .chan nav a:hover{color:var(--chu-kem)}
.kem .chan-duoi{border-top-color:rgba(27,23,20,.14)}
@media (max-width:900px){
  body.kem{font-size:17.5px}
  .kem .menu summary{border-color:rgba(27,23,20,.28)}
  .kem .menu summary svg{stroke:var(--chu-kem)}
  .kem .menu ul{background:#FBF8F2;border-color:rgba(27,23,20,.14);box-shadow:0 24px 60px rgba(27,23,20,.22)}
  .kem .menu li a{color:var(--chu-kem)}
  .kem .menu li a:active{background:rgba(27,23,20,.05)}
  .kem .menu li.tach{border-top-color:rgba(27,23,20,.14)}
  .nam-dieu li{grid-template-columns:44px 1fr;column-gap:14px}
  .nam-dieu .so{font-size:46px}
  .o-chep pre{font-size:20px;padding:18px}
  .o-chep-dau{padding-left:18px}
  .ghi-chu{padding:20px;font-size:16.5px}
  .bai-anh img{aspect-ratio:4/3}
}

/* =====================================================
   ĐỢT 2 · khung nội dung: thẻ bài viết, danh sách học, trang bài có mục lục, trang về mình
   (chỉ thêm; các luật ở trên giữ nguyên)
   ===================================================== */
/* liên kết chữ có mũi tên, nền tối */
.lien{display:inline-flex;align-items:center;gap:8px;min-height:44px;font-weight:600;font-size:16.5px;color:var(--chu);border-bottom:1.5px solid var(--vach-dam);transition:border-color .2s ease-out}
.lien svg{width:18px;height:18px;flex:none;transition:transform .2s var(--em-ra)}
.ve-chu .lien{margin-top:26px}
.hang-lien{display:flex;flex-wrap:wrap;gap:6px 28px;margin-top:26px}
.hang-lien .lien{margin-top:0}
.lien.mo{color:var(--phu);border-bottom-color:transparent}
@media (hover:hover) and (pointer:fine){
  .lien:hover{border-bottom-color:var(--chu);color:var(--chu)}
  .lien:hover svg{transform:translateX(3px)}
}
.kem .lien{color:var(--chu-kem);border-bottom-color:rgba(27,23,20,.3)}

/* thẻ nổi ở màn đầu: ô nhỏ nay là ảnh bìa thật */
.video-nho .khung-nho{overflow:hidden;place-items:end end}
.video-nho .khung-nho img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover}
.video-nho .khung-nho .choi{position:relative;width:22px;height:22px;margin:0 6px 6px 0;box-shadow:0 2px 8px rgba(0,0,0,.5)}
.video-nho .khung-nho .choi::after{border-left-width:7px;border-top-width:5px;border-bottom-width:5px;margin-left:2px}

/* bài nổi bật: thẻ kem, chữ bên trái, ảnh bìa bên phải */
.noi-bat{padding-top:0;padding-bottom:clamp(28px,3.4vw,48px)}
.bai-chinh h2.tit{margin-top:16px;font-size:clamp(1.8rem,3vw,2.6rem);line-height:1.1}
.loi>a[aria-current]{color:var(--chu)}
.kem .loi>a[aria-current]{color:var(--chu-kem)}
.bai-hinh{position:relative;border-radius:16px;overflow:hidden;box-shadow:0 22px 44px -26px rgba(27,23,20,.7)}
.bai-hinh img{width:100%;aspect-ratio:16/9;object-fit:cover}
.bai-meta{display:block;margin-top:14px;font-size:14px;font-weight:500;color:#6B6157;letter-spacing:.01em}
.bai-chinh p + .bai-meta{margin-top:18px}

/* thẻ video kèm bài viết */
.luoi-the{display:grid;grid-template-columns:repeat(4,1fr);gap:clamp(14px,1.7vw,22px)}
.luoi-the.ba{grid-template-columns:repeat(3,1fr)}
.the-bai{position:relative;display:flex;flex-direction:column;height:100%;background:var(--the);border:1px solid var(--vach);border-radius:var(--bo);overflow:hidden;transition:border-color .2s ease-out,transform .25s var(--em-ra)}
.the-bia{position:relative;display:block;aspect-ratio:16/9;overflow:hidden;background:var(--nen);border-bottom:1px solid var(--vach)}
.the-bia img{width:100%;height:100%;object-fit:cover;transition:transform .6s var(--em-ra)}
.the-dai{position:absolute;right:10px;bottom:10px;padding:5px 8px;border-radius:7px;background:rgba(16,14,12,.86);font-size:12.5px;font-weight:600;line-height:1;font-variant-numeric:tabular-nums}
.the-than{display:flex;flex-direction:column;flex:1;padding:18px 18px 8px}
.the-than .nhan-nho{font-size:11.5px;letter-spacing:.13em}
.the-than h3{margin-top:10px;font-size:clamp(1.3rem,1.75vw,1.45rem);line-height:1.17;text-wrap:pretty}
.the-than h3 a::after{content:"";position:absolute;inset:0}
.the-meta{margin-top:10px;color:var(--phu);font-size:13.5px;line-height:1.4}
.the-chan{margin-top:auto;padding-top:14px}
.the-doc{display:flex;align-items:center;gap:7px;min-height:44px;color:var(--nhan);font-weight:600;font-size:15.5px}
.the-doc svg,.the-fb svg{width:17px;height:17px;flex:none;transition:transform .2s var(--em-ra)}
.the-fb{position:relative;z-index:1;display:flex;align-items:center;gap:7px;min-height:46px;border-top:1px solid var(--vach);color:var(--phu);font-size:14px;font-weight:500;transition:color .15s ease-out}
.the-fb svg{width:15px;height:15px}
@media (hover:hover) and (pointer:fine){
  .the-bai:hover{border-color:var(--vach-dam);transform:translateY(-3px)}
  .the-bai:hover .the-bia img{transform:scale(1.03)}
  .the-bai:hover .the-doc svg{transform:translateX(3px)}
  .the-fb:hover{color:var(--chu)}
}

/* học miễn phí: danh sách bài hướng dẫn */
.hoc{background:var(--nen2);border-top:1px solid var(--vach)}
.hoc-luoi{display:grid;grid-template-columns:1fr 1.55fr;gap:clamp(32px,6vw,96px);align-items:start}
.hoc-dau{position:sticky;top:120px}
.hoc-dau p:not(.nhan-nho){margin-top:20px;color:var(--phu);max-width:400px;text-wrap:pretty}
.hoc-dau .lien{margin-top:24px}
.ds-bai{border-top:1px solid var(--vach)}
.ds-bai li{border-bottom:1px solid var(--vach)}
.ds-bai a{display:grid;grid-template-columns:34px 136px 1fr 20px;column-gap:18px;align-items:center;padding:16px 0}
.ds-bai i{font-family:var(--serif);font-style:italic;font-weight:500;font-size:24px;color:var(--nhan);line-height:1}
.ds-bai img{width:136px;aspect-ratio:16/9;object-fit:cover;border-radius:10px;border:1px solid var(--vach)}
.ds-bai b{display:block;font-family:var(--serif);font-weight:600;font-size:clamp(1.2rem,1.7vw,1.4rem);line-height:1.2;letter-spacing:-.01em;text-wrap:pretty}
.ds-bai span{display:block;margin-top:6px;color:var(--phu);font-size:13.5px;line-height:1.4}
.ds-bai svg{width:20px;height:20px;color:var(--phu);transition:transform .2s var(--em-ra),color .2s ease-out}
@media (hover:hover) and (pointer:fine){
  .ds-bai a:hover svg{transform:translateX(4px);color:var(--chu)}
  .ds-bai a:hover b{color:#fff}
}

/* đầu trang phụ (trang danh sách bài, trang về mình) */
.dau-trang-phu{position:relative;margin-top:-84px;padding-top:84px;overflow:hidden}
.dau-trang-phu .khung{position:relative;padding-top:clamp(40px,6vw,84px);padding-bottom:clamp(32px,4vw,56px)}
.dau-trang-phu h1{font-size:clamp(2.4rem,5.2vw,4rem);margin-top:20px;max-width:880px}
.dau-trang-phu .mo-dau{max-width:620px}
.dau-trang-phu>.khung>*{animation:len .8s var(--em-ra) backwards}
.dau-trang-phu>.khung>:nth-child(2){animation-delay:60ms}
.dau-trang-phu>.khung>:nth-child(3){animation-delay:120ms}

/* trang về mình */
.ve-dau .khung{display:grid;grid-template-columns:1.25fr 1fr;gap:clamp(32px,6vw,96px);align-items:center}
.ve-dau .ve-anh{margin-left:auto;width:100%;max-width:420px;animation:hien-anh 1s var(--em-ra) 120ms backwards}
.ve-dau h1{font-size:clamp(2.4rem,5vw,3.9rem);margin-top:20px}
.ve-dau .doan{font-size:18px;line-height:1.7;max-width:560px}
.ve-dau .doan.dau-tien{color:var(--chu);margin-top:28px}
.ve-dau .ba-so{margin-top:38px}
.moc{border-top:1px solid var(--vach);max-width:820px}
.moc li{display:grid;grid-template-columns:150px 1fr;column-gap:24px;padding:20px 0 21px;border-bottom:1px solid var(--vach);align-items:baseline}
.moc i{font-family:var(--serif);font-style:italic;font-weight:500;font-size:20px;color:var(--nhan);line-height:1.4;font-variant-numeric:lining-nums}
.moc b{display:block;font-weight:600;font-size:18px;line-height:1.4}
.moc span{display:block;margin-top:5px;color:var(--phu);font-size:16px;line-height:1.6}
.tuyen{display:grid;grid-template-columns:repeat(3,1fr);gap:clamp(14px,1.7vw,22px)}
.tuyen li{background:var(--the);border:1px solid var(--vach);border-radius:var(--bo);padding:24px 24px 14px}
.tuyen h3{font-size:1.5rem;margin-top:12px}
.tuyen p{margin-top:10px;color:var(--phu);font-size:15.5px;line-height:1.6}
.tuyen ul{margin-top:14px;border-top:1px solid var(--vach)}
.tuyen ul a{display:flex;align-items:center;justify-content:space-between;gap:12px;min-height:48px;padding:8px 0;font-size:15.5px;font-weight:500;line-height:1.35;border-bottom:1px solid var(--vach)}
.tuyen ul li{background:none;border:0;border-radius:0;padding:0}
.tuyen ul li:last-child a{border-bottom:0}
.tuyen ul svg{width:16px;height:16px;flex:none;color:var(--nhan)}
.keu{display:flex;align-items:center;justify-content:space-between;gap:24px 48px;flex-wrap:wrap}
.keu .hang-nut{margin-top:0}

/* ---------- trang bài: mục lục, phần đánh số, hình, bảng ---------- */
.bai-khung{width:100%;max-width:calc(680px + 2*var(--le));margin-inline:auto;padding-inline:var(--le)}
.bai-dau .bai-meta{margin-top:22px;font-size:14.5px;color:#5A5148}
.video-to{position:relative;display:block;margin-top:clamp(26px,4vw,36px);border-radius:20px;overflow:hidden;background:var(--nen);box-shadow:0 30px 60px -34px rgba(27,23,20,.7);animation:hien-anh 1s var(--em-ra) 200ms backwards}
.video-to img{width:100%;aspect-ratio:16/9;object-fit:cover;transition:transform .6s var(--em-ra)}
.video-to-chu{position:absolute;left:0;right:0;bottom:0;display:flex;align-items:center;gap:14px;padding:44px 18px 16px;background:linear-gradient(180deg,rgba(16,14,12,0),rgba(16,14,12,.92) 62%);color:var(--chu)}
.video-to .choi{flex:none;width:46px;height:46px}
.video-to .choi::after{border-left-width:13px;border-top-width:8px;border-bottom-width:8px;margin-left:4px}
.video-to b{display:block;font-size:17px;font-weight:600;line-height:1.3}
.video-to i{display:block;font-style:normal;font-size:14px;color:#CFC7BA;line-height:1.4}
figure.video-to .video-to-chu{padding-top:30px}
@media (hover:hover) and (pointer:fine){
  a.video-to:hover img{transform:scale(1.02)}
  a.video-to:hover .choi{transform:scale(1.08)}
}
.muc-luc{margin-top:clamp(26px,4vw,36px);padding:18px 22px 10px;border-radius:18px;background:#EAE3D6}
.muc-luc h2{font-family:var(--sans);font-size:13px;font-weight:600;letter-spacing:.16em;text-transform:uppercase;color:#6B6157;line-height:1.4}
.muc-luc ol{margin-top:8px;counter-reset:ml}
.muc-luc li a{display:grid;grid-template-columns:30px 1fr;align-items:baseline;min-height:44px;padding:10px 0;font-size:16px;line-height:1.35;color:#3B342E;border-top:1px solid rgba(27,23,20,.1);transition:color .15s ease-out}
.muc-luc li:first-child a{border-top:0}
.muc-luc li a::before{counter-increment:ml;content:counter(ml);font-family:var(--serif);font-style:italic;font-weight:500;font-size:19px;color:var(--nhan-kem);line-height:1}
.muc-luc li a:hover,.muc-luc li a.dang{color:var(--chu-kem)}
.muc-luc li a.dang{font-weight:600}
.muc-luc .ve-truoc{display:none}
.phan{scroll-margin-top:96px}
.phan + .phan,.than>p + .phan,.than>.ghi-chu + .phan{margin-top:clamp(52px,7vw,80px)}
.so-phan{display:flex;align-items:center;gap:12px;color:var(--nhan-kem)!important}
.so-phan::before{content:"";flex:none;width:24px;height:1.5px;border-radius:1px;background:var(--nhan-kem)}
.than .phan h2.tit{margin-top:12px}
.than h3.tit{margin-top:34px;font-size:clamp(1.4rem,2.6vw,1.65rem);line-height:1.2}
.than b{font-weight:600}
.gach{margin-top:14px}
.gach li{position:relative;padding-left:24px;margin-top:10px;text-wrap:pretty}
.gach li::before{content:"";position:absolute;left:0;top:.8em;width:12px;height:1.5px;background:var(--nhan-kem)}
.than .nam-dieu p{margin-top:6px}
.hinh{margin-top:28px;border:1px solid rgba(27,23,20,.14);border-radius:20px;background:#FBF8F2;padding:clamp(18px,3.2vw,30px) clamp(12px,3vw,30px) clamp(14px,2vw,20px)}
.hinh svg{width:100%;height:auto;margin-inline:auto;overflow:visible}
.hinh figcaption{margin-top:clamp(14px,2vw,20px);padding-top:14px;border-top:1px solid rgba(27,23,20,.12);font-size:15px;line-height:1.55;color:#5A5148;text-align:center;text-wrap:balance}
.k-o{fill:#fff;stroke:rgba(27,23,20,.38);stroke-width:1.2}
.k-o.cam{fill:rgba(168,74,39,.09);stroke:var(--nhan-kem)}
.k-o.mo{fill:none;stroke-dasharray:4 5}
.k-n{fill:none;stroke:var(--chu-kem);stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round}
.k-n.cam{stroke:var(--nhan-kem)}
.k-day{fill:none;stroke:rgba(27,23,20,.4);stroke-width:1.2;stroke-linecap:round;stroke-linejoin:round}
.k-day.dut{stroke-dasharray:2 6}
.k-ten{font-family:var(--sans);font-weight:600;font-size:15px;fill:var(--chu-kem)}
.k-viec{font-family:var(--sans);font-weight:400;font-size:13.5px;fill:#5A5148}
.k-cam{fill:var(--nhan-kem)}
.k-so{font-family:var(--serif);font-weight:600;font-size:34px;fill:var(--chu-kem);font-variant-numeric:lining-nums}
.bang-cuon{margin-top:26px;overflow-x:auto}
.bang{width:100%;border-collapse:collapse;font-size:17px;line-height:1.5}
.bang th,.bang td{text-align:left;vertical-align:top;padding:14px 16px 15px 0;border-bottom:1px solid rgba(27,23,20,.14)}
.bang th:last-child,.bang td:last-child{padding-right:0}
.bang thead th{font-size:13px;font-weight:600;letter-spacing:.14em;text-transform:uppercase;color:#6B6157;padding-bottom:10px;border-bottom-color:rgba(27,23,20,.3)}
.bang tbody th{font-weight:600;white-space:nowrap}
.bang td.so-cot{font-family:var(--serif);font-style:italic;font-size:21px;color:var(--nhan-kem);width:34px}
.o-chep + .o-chep{margin-top:16px}
.o-chep pre.thuong{font-family:var(--sans);font-size:17px;line-height:1.65}
.o-chep + p.chu-thich,.hinh + p.chu-thich{margin-top:12px;font-size:15.5px;color:#5A5148}
.ghi-chu.vien{background:none;border:1.5px solid var(--nhan-kem)}
.giong{margin-top:clamp(36px,5vw,48px);padding-top:22px;border-top:1px solid rgba(27,23,20,.14);font-size:16px;color:#4D453D}
.giong + .nguon{margin-top:22px;border-top:0;padding-top:0}
.doc-tiep{margin-top:clamp(40px,5vw,56px)}
.doc-tiep h2{font-family:var(--sans);font-size:13px;font-weight:600;letter-spacing:.16em;text-transform:uppercase;color:#6B6157;line-height:1.4}
.doc-tiep ul{margin-top:14px;display:grid;gap:12px}
.tiep{display:grid;grid-template-columns:136px 1fr;gap:16px;align-items:center;padding:12px;border:1px solid rgba(27,23,20,.16);border-radius:16px;transition:border-color .2s ease-out}
.tiep:hover{border-color:rgba(27,23,20,.42)}
.tiep img{width:136px;aspect-ratio:16/9;object-fit:cover;border-radius:9px}
.tiep b{display:block;font-family:var(--serif);font-weight:600;font-size:21px;line-height:1.2;letter-spacing:-.01em}
.tiep span span{display:block;margin-top:5px;font-size:14px;color:#5A5148}
@media (min-width:1140px){
  .bai-khung{max-width:calc(1016px + 2*var(--le));display:grid;grid-template-columns:232px minmax(0,680px);column-gap:104px;align-items:start}
  .bai-dau{grid-column:2;grid-row:1}
  .than{grid-column:2;grid-row:2}
  .muc-luc{grid-column:1;grid-row:1/span 2;position:sticky;top:104px;margin-top:clamp(28px,5vw,72px);padding:8px 0 0;background:none;border-radius:0;max-height:calc(100vh - 128px);overflow-y:auto}
  .muc-luc ol{margin-top:12px}
  .muc-luc li a{font-size:15px;grid-template-columns:28px 1fr;padding:9px 0;min-height:0;color:#5A5148;border-top:0}
  .muc-luc li a::before{font-size:17px}
  .muc-luc li a.dang{color:var(--chu-kem)}
  .muc-luc .ve-truoc{display:inline-flex;margin-top:14px;padding-top:6px;border-top:1px solid rgba(27,23,20,.14);width:100%;font-size:14px}
  .bai-dau>.ve-truoc{visibility:hidden;height:0;min-height:0;overflow:hidden}
}
@media (max-width:1099px){
  .luoi-the,.luoi-the.ba{grid-template-columns:1fr 1fr}
}
@media (max-width:900px){
  .hoc-luoi,.ve-dau .khung{grid-template-columns:1fr}
  .hoc-dau{position:static}
  .dau-trang-phu{margin-top:-72px;padding-top:72px}
  .ve-dau .ve-anh{margin:0 18px 0 0;max-width:420px}
  .ve-dau .doan{font-size:17px}
  .tuyen{grid-template-columns:1fr}
  .moc li{grid-template-columns:118px 1fr;column-gap:16px}
  .keu .hang-nut{width:100%}
  .bang{font-size:16px}
  .o-chep pre.thuong{font-size:16px}
}
@media (max-width:599px){
  .luoi-the,.luoi-the.ba{grid-template-columns:1fr}
  .ds-bai a{grid-template-columns:24px 104px 1fr;column-gap:12px;padding:14px 0}
  .ds-bai svg{display:none}
  .ds-bai img{width:104px}
  .ds-bai i{font-size:21px}
  .ds-bai b{font-size:18.5px}
  .tiep{grid-template-columns:104px 1fr;gap:12px;padding:10px}
  .tiep img{width:104px}
  .tiep b{font-size:19px}
  .moc li{grid-template-columns:1fr}
  .bang tbody th{white-space:normal}
}

.ds-bai picture,.tiep picture,.video-nho .khung-nho picture{display:block}
.video-nho .khung-nho picture{position:absolute;inset:0}
.video-to-chu{position:static;padding:14px 18px;background:#1D1814}
figure.video-to .video-to-chu{padding-top:14px}
/* đợt 2b: thư tin đúng khuôn (ô email khóa), khối lớp học, hàng khóa học */
.thu-moi{align-items:center}
.thu-o{position:relative;flex:0 1 460px;min-width:0}
.thu-hang{display:flex;gap:10px}
.thu-hang input{flex:1;min-width:0;height:54px;padding:0 18px;border-radius:14px;border:1px dashed var(--vach-dam);background:rgba(245,240,232,.04);color:var(--phu);font:inherit;font-size:16px;cursor:not-allowed}
.thu-hang input::placeholder{color:var(--phu);opacity:1}
.thu-nho{margin-top:12px;color:var(--phu);font-size:14px;line-height:1.5}
.lop-the{margin-bottom:28px}
.lop-the:not(:has(*)){display:none}
.hoc-nhom{margin:0 0 12px}
.khoa + .hoc-nhom{margin-top:36px}
.khoa{display:flex;align-items:center;justify-content:space-between;gap:16px 24px;flex-wrap:wrap;padding:20px 22px;border:1px solid var(--vach);border-radius:var(--bo);background:var(--the);transition:border-color .2s ease-out}
.khoa b{display:block;font-family:var(--serif);font-weight:600;font-size:clamp(1.35rem,2vw,1.6rem);line-height:1.2}
.khoa span span{display:block;margin-top:5px;color:var(--phu);font-size:13.5px}
.khoa-di{display:inline-flex;align-items:center;gap:7px;color:var(--nhan);font-weight:600;font-size:15.5px}
.khoa-di svg{width:17px;height:17px}
.khoa:hover{border-color:var(--vach-dam)}
@media (max-width:1180px){.loi{gap:22px;font-size:15px}}
@media (max-width:900px){.thu-o{margin-top:22px}.thu-moi .nut{width:auto;margin-top:0;flex:none}}
@media (max-width:420px){.thu-hang{flex-direction:column}.thu-hang input{flex:none;width:100%}.thu-moi .nut{width:100%}}

/* ---------- giảm chuyển động (để cuối tệp cho thắng mọi luật ở trên) ---------- */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .js .hien{transform:none;transition:opacity .3s ease-out;transition-delay:0ms}
  .dau-chu>*,.chan-dung,.video-nho,.bai-dau>*,.bai-anh img{animation:none}
  .nut,.video-nho,.choi,.choi::after,.bai-chinh,.vid-bia img,.doc-bai svg,.o-chep button{transition:none}
  .the-bai,.the-bia img,.video-to img,.lien svg,.the-doc svg,.ds-bai svg{transition:none}
  .dau-trang-phu>.khung>*,.ve-dau .ve-anh,.video-to{animation:none}
  .the-bai:hover,.the-bai:hover .the-bia img,a.video-to:hover img,a.video-to:hover .choi,.lien:hover svg,.the-bai:hover .the-doc svg,.ds-bai a:hover svg{transform:none}
  .nut:active,.o-chep button:active,.video-nho:hover,.video-nho:hover .choi,.bai-chinh:hover,.vid:hover .vid-bia img,.bai-chinh:hover .doc-bai svg{transform:none}
}