/* Victor Hoang AI · khu LỚP HỌC AI · nạp SAU trang.css
   Chỉ thêm lớp có tiền tố lh- (và b- trong hình bìa). Không đổi luật nào của trang.css.
   Màu, phông, bo góc lấy từ biến của trang.css (bộ nhận diện 2.3). */

/* ---------- nhãn trạng thái ---------- */
.lh-chip{display:inline-flex;align-items:center;gap:8px;min-height:30px;padding:4px 12px;border-radius:999px;border:1px solid var(--vach-dam);font-size:12.5px;font-weight:600;letter-spacing:.03em;line-height:1.2;color:var(--chu);white-space:nowrap}
.lh-chip::before{content:"";flex:none;width:7px;height:7px;border-radius:50%;background:var(--nhan)}
.lh-chip.cho{color:var(--phu);border-color:var(--vach)}
.lh-chip.cho::before{background:none;box-shadow:inset 0 0 0 1.5px var(--phu)}
.lh-hang-chip{display:flex;flex-wrap:wrap;gap:8px}

/* ---------- hình bìa lớp (HTML + SVG nét mảnh, một màu nhấn) ---------- */
.lh-bia{position:relative;aspect-ratio:16/10;overflow:hidden;background:var(--nen);border-bottom:1px solid var(--vach)}
.lh-bia::before{content:"";position:absolute;right:-28%;top:-78%;width:112%;aspect-ratio:1;border-radius:50%;background:radial-gradient(circle,rgba(var(--glow),.28),rgba(var(--glow),0) 62%);pointer-events:none}
.lh-bia::after{content:"";position:absolute;inset:0;background-image:radial-gradient(rgba(245,240,232,.09) 1px,transparent 1.2px);background-size:18px 18px;-webkit-mask-image:linear-gradient(180deg,transparent,#000 70%);mask-image:linear-gradient(180deg,transparent,#000 70%);pointer-events:none}
.lh-bia svg{position:absolute;inset:0;width:100%;height:100%;z-index:1;transition:transform .6s var(--em-ra)}
.b-n{fill:none;stroke:rgba(245,240,232,.84);stroke-width:1.6;stroke-linecap:round;stroke-linejoin:round}
.b-m{fill:none;stroke:rgba(245,240,232,.3);stroke-width:1.2;stroke-linecap:round;stroke-linejoin:round}
.b-c{fill:none;stroke:var(--nhan);stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round}
.b-o{fill:#1D1814;stroke:rgba(245,240,232,.5);stroke-width:1.2}
.b-o.cam{stroke:var(--nhan)}
.b-t{font-family:var(--sans);font-weight:600;font-size:11px;letter-spacing:.08em;fill:#ADA396}
.b-t.to{font-size:12.5px;fill:#F5F0E8;letter-spacing:.02em}
.b-s{font-family:var(--serif);font-style:italic;font-weight:500;font-size:30px;fill:var(--nhan)}

/* ---------- lưới thẻ lớp ---------- */
.lh-luoi{display:grid;grid-template-columns:repeat(3,1fr);gap:clamp(14px,1.7vw,22px)}
.lh-the{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)}
.lh-the-than{display:flex;flex-direction:column;align-items:flex-start;flex:1;padding:20px 20px 10px}
.lh-the h3.tit{margin-top:14px;font-size:clamp(1.5rem,2.1vw,1.75rem);line-height:1.14;text-wrap:pretty}
.lh-the h3 a::after{content:"";position:absolute;inset:0;z-index:2}
.lh-the-mo{margin-top:10px;color:var(--phu);font-size:15.5px;line-height:1.6;text-wrap:pretty}
.lh-the-cho{margin-top:14px;padding-top:14px;border-top:1px solid var(--vach);width:100%;font-size:14.5px;line-height:1.55;color:var(--chu)}
.lh-the-cho b{display:block;font-size:11.5px;font-weight:600;letter-spacing:.14em;text-transform:uppercase;color:var(--phu);margin-bottom:4px}
.lh-the-meta{margin-top:12px;color:var(--phu);font-size:13.5px;line-height:1.4}
.lh-the .the-chan{width:100%}
.lh-luoi>li:first-child{grid-column:1/-1}
.lh-the.lon{flex-direction:row}
.lh-the.lon .lh-bia{flex:none;width:46%;aspect-ratio:auto;min-height:340px;border-bottom:0;border-right:1px solid var(--vach)}
.lh-the.lon .lh-the-than{padding:clamp(22px,3vw,40px) clamp(20px,3vw,40px) clamp(14px,2vw,26px)}
.lh-the.lon h3.tit{font-size:clamp(1.9rem,3.2vw,2.7rem);line-height:1.08}
.lh-the.lon .lh-the-mo{font-size:17px;max-width:520px}
@media (hover:hover) and (pointer:fine){
  .lh-the:hover{border-color:var(--vach-dam);transform:translateY(-3px)}
  .lh-the:hover .lh-bia svg{transform:scale(1.03)}
  .lh-the:hover .the-doc svg{transform:translateX(3px)}
}
.lh-the:focus-within{border-color:var(--vach-dam)}

/* ---------- các bước đánh số (học theo thứ tự nào, việc làm theo) ---------- */
.lh-buoc{border-top:1px solid var(--vach);max-width:860px}
.lh-buoc>li{display:grid;grid-template-columns:72px 1fr;column-gap:16px;padding:22px 0 23px;border-bottom:1px solid var(--vach);align-items:baseline}
.lh-buoc>li>i{font-family:var(--serif);font-style:italic;font-weight:500;font-size:34px;color:var(--nhan);line-height:1;font-variant-numeric:lining-nums}
.lh-buoc b{display:block;font-weight:600;font-size:18.5px;line-height:1.4}
.lh-buoc p{margin-top:6px;color:var(--phu);font-size:16px;line-height:1.6;max-width:620px;text-wrap:pretty}
.lh-buoc-chan{display:flex;flex-wrap:wrap;align-items:center;gap:6px 22px;margin-top:12px}
.lh-buoc .lien{font-size:15.5px}
.thu.lh-cach{padding-top:var(--muc)}

/* ---------- hỏi đáp ---------- */
.lh-hoi{border-top:1px solid var(--vach);max-width:860px}
.lh-hoi details{border-bottom:1px solid var(--vach)}
.lh-hoi summary{display:flex;align-items:center;justify-content:space-between;gap:20px;min-height:64px;padding:16px 0;cursor:pointer;list-style:none;font-weight:600;font-size:18px;line-height:1.4}
.lh-hoi summary::-webkit-details-marker{display:none}
.lh-hoi summary::after{content:"";flex:none;width:14px;height:14px;background:linear-gradient(var(--nhan),var(--nhan)) center/100% 1.5px no-repeat,linear-gradient(var(--nhan),var(--nhan)) center/1.5px 100% no-repeat;transition:transform .25s var(--em-ra)}
.lh-hoi details[open] summary::after{transform:rotate(45deg)}
.lh-hoi details p{padding:0 34px 22px 0;color:var(--phu);font-size:16.5px;line-height:1.65;max-width:700px;text-wrap:pretty}
.lh-hoi details p + p{margin-top:-10px}
.lh-hoi a{color:var(--chu);border-bottom:1px solid var(--vach-dam)}
@media (hover:hover) and (pointer:fine){.lh-hoi summary:hover{color:#fff}.lh-hoi a:hover{border-bottom-color:var(--chu)}}

/* ---------- đầu trang lớp (tổng quan lớp, trang bán) ---------- */
.lh-dau .khung{display:grid;grid-template-columns:1.18fr 1fr;gap:clamp(32px,5vw,80px);align-items:center}
.lh-dau h1{font-size:clamp(2.4rem,4.9vw,3.9rem);margin-top:20px}
.lh-dau .mo-dau{max-width:560px}
.lh-dau .lh-hang-chip{margin-top:22px}
.lh-dau .ba-so{margin-top:38px;flex-wrap:wrap;row-gap:22px}
.lh-dau-bia{position:relative;border:1px solid var(--vach);border-radius:22px;overflow:hidden;background:var(--nen2);box-shadow:0 40px 90px -30px rgba(0,0,0,.7);animation:hien-anh 1s var(--em-ra) 120ms backwards}
.lh-dau-bia .lh-bia{aspect-ratio:5/4;border-bottom:0}
.lh-dau-bia figcaption{padding:16px 20px 18px;border-top:1px solid var(--vach);color:var(--phu);font-size:14.5px;line-height:1.5}
.lh-ghi{margin-top:16px;color:var(--phu);font-size:14.5px;line-height:1.55;max-width:520px}
.lh-duong{display:flex;flex-wrap:wrap;align-items:center;gap:6px 10px;font-size:14px;font-weight:500;color:var(--phu)}
.lh-duong a{display:inline-flex;align-items:center;min-height:44px}
.lh-duong a:hover{color:var(--chu)}
.lh-duong span[aria-hidden]{opacity:.5}
.lh-nut-dai{height:auto;min-height:54px;padding-block:12px;white-space:normal;text-align:center;line-height:1.25}

/* ---------- học xong làm được gì ---------- */
.lh-kq{display:grid;grid-template-columns:repeat(4,1fr);gap:clamp(14px,1.7vw,22px)}
.lh-kq li{background:var(--the);border:1px solid var(--vach);border-radius:var(--bo);padding:22px 22px 24px}
.lh-kq .nhan-nho{font-size:11.5px;letter-spacing:.13em}
.lh-kq b{display:block;margin-top:12px;font-family:var(--serif);font-weight:600;font-size:1.45rem;line-height:1.18;letter-spacing:-.01em;text-wrap:pretty}
.lh-kq p{margin-top:10px;color:var(--phu);font-size:15.5px;line-height:1.6;text-wrap:pretty}

/* ---------- dành cho ai · không dành cho ai ---------- */
.lh-hai{display:grid;grid-template-columns:1fr 1fr;gap:clamp(14px,1.7vw,22px)}
.lh-hai>div{border:1px solid var(--vach);border-radius:var(--bo);padding:clamp(22px,3vw,34px)}
.lh-hai>div:first-child{background:var(--the)}
.lh-hai h3{font-size:clamp(1.5rem,2.3vw,1.85rem)}
.lh-hai ul{margin-top:16px}
.lh-hai li{position:relative;padding:12px 0 12px 30px;border-top:1px solid var(--vach);color:var(--chu);font-size:16.5px;line-height:1.55;text-wrap:pretty}
.lh-hai li::before{content:"";position:absolute;left:2px;top:1.3em;width:13px;height:7px;border-left:1.8px solid var(--nhan);border-bottom:1.8px solid var(--nhan);transform:rotate(-45deg);transform-origin:left bottom;margin-top:-8px}
.lh-hai .khong li{color:var(--phu)}
.lh-hai .khong li::before{width:13px;height:1.6px;border:0;background:var(--phu);transform:none;margin-top:0;top:1.55em}

/* ---------- đề cương: phần và bài ---------- */
.lh-de{display:grid;gap:clamp(28px,4vw,44px);max-width:920px}
.lh-phan-dau{display:flex;align-items:baseline;justify-content:space-between;gap:10px 24px;flex-wrap:wrap}
.lh-phan-dau h3{font-size:clamp(1.6rem,2.6vw,2.05rem);margin-top:8px}
.lh-phan-dau>span{color:var(--phu);font-size:14px;white-space:nowrap}
.lh-ds{margin-top:16px;border-top:1px solid var(--vach)}
.lh-ds>li{border-bottom:1px solid var(--vach)}
.lh-bai{display:grid;grid-template-columns:44px 1fr auto 20px;column-gap:16px;align-items:center;padding:17px 0 18px}
.lh-bai>i{font-family:var(--serif);font-style:italic;font-weight:500;font-size:26px;color:var(--nhan);line-height:1;font-variant-numeric:lining-nums}
.lh-bai b{display:block;font-family:var(--serif);font-weight:600;font-size:clamp(1.25rem,1.8vw,1.45rem);line-height:1.2;letter-spacing:-.01em;text-wrap:pretty}
.lh-bai>span>span{display:block;margin-top:5px;color:var(--phu);font-size:14.5px;line-height:1.5;text-wrap:pretty}
.lh-bai>em{font-family:var(--sans);font-style:normal;font-weight:500;font-size:13.5px;color:var(--phu);white-space:nowrap}
.lh-bai>svg{width:20px;height:20px;color:var(--phu);transition:transform .2s var(--em-ra),color .2s ease-out}
div.lh-bai{grid-template-columns:44px 1fr auto}
@media (hover:hover) and (pointer:fine){
  a.lh-bai:hover>svg{transform:translateX(4px);color:var(--chu)}
  a.lh-bai:hover b{color:#fff}
}
.lh-keu{margin-top:clamp(28px,4vw,44px);display:flex;flex-wrap:wrap;align-items:center;gap:14px 24px}
.lh-keu span{color:var(--phu);font-size:15px}

/* ---------- trang bán: các khối "học được gì" ---------- */
.lh-khoi{display:grid;gap:clamp(14px,1.7vw,22px)}
.lh-khoi>li{display:grid;grid-template-columns:1fr 1fr;gap:clamp(20px,4vw,56px);align-items:center;border:1px solid var(--vach);border-radius:22px;background:var(--the);padding:clamp(22px,3.4vw,44px)}
.lh-khoi .so{font-size:44px}
.lh-khoi h3{margin-top:14px;font-size:clamp(1.6rem,2.6vw,2.1rem)}
.lh-khoi p{margin-top:12px;color:var(--phu);font-size:16.5px;line-height:1.65;max-width:480px;text-wrap:pretty}
.lh-khoi ul{margin-top:14px}
.lh-khoi ul li{position:relative;padding-left:22px;margin-top:8px;font-size:16px;line-height:1.55;color:var(--chu);text-wrap:pretty}
.lh-khoi ul li::before{content:"";position:absolute;left:0;top:.78em;width:11px;height:1.5px;background:var(--nhan)}
.lh-trich{border:1px solid var(--vach);border-radius:16px;background:var(--nen);overflow:hidden;min-width:0}
.lh-trich figcaption{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:11px 16px;border-bottom:1px solid var(--vach);font-size:11.5px;font-weight:600;letter-spacing:.14em;text-transform:uppercase;color:var(--phu)}
.lh-trich pre{margin:0;padding:16px 16px 18px;font-family:var(--sans);font-size:14.5px;line-height:1.65;color:#DCD5C9;white-space:pre-wrap;overflow-wrap:anywhere}
.lh-trich pre i{font-style:normal;color:var(--nhan)}

/* ---------- về người dạy (trang bán) ---------- */
.lh-nguoi{display:grid;grid-template-columns:minmax(0,300px) 1fr;gap:clamp(28px,6vw,88px);align-items:center}
.lh-nguoi img{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)}
.lh-nguoi p:not(.nhan-nho){margin-top:18px;color:var(--phu);font-size:17.5px;line-height:1.7;max-width:560px;text-wrap:pretty}
.lh-nguoi h2 + p:not(.nhan-nho){margin-top:26px;color:var(--chu)}
.lh-nguoi .lien{margin-top:24px}

/* ---------- trang bài học (nền kem) ---------- */
.lh-tien{display:flex;align-items:center;gap:14px;margin-top:18px;font-size:14px;font-weight:600;color:#5A5148;font-variant-numeric:tabular-nums}
.lh-tien span.thanh{flex:1;max-width:220px;height:3px;border-radius:2px;background:rgba(27,23,20,.14);overflow:hidden}
.lh-tien span.thanh>span{display:block;height:100%;border-radius:2px;background:var(--nhan-kem)}
.lh-viec{margin-top:26px;padding:24px 26px 12px;border-radius:18px;border:1.5px solid var(--nhan-kem)}
.lh-viec ol{margin-top:14px;counter-reset:v}
.lh-viec ol li{position:relative;padding:14px 0 14px 44px;border-top:1px solid rgba(27,23,20,.14);font-size:18px;line-height:1.6;text-wrap:pretty}
.lh-viec ol li::before{counter-increment:v;content:counter(v);position:absolute;left:2px;top:9px;font-family:var(--serif);font-style:italic;font-weight:500;font-size:28px;line-height:1.3;color:var(--nhan-kem)}
.than .lh-viec p{margin-top:8px;font-size:17px;color:#3B342E}
.lh-chuyen{margin-top:clamp(40px,5vw,56px);display:grid;grid-template-columns:1fr 1fr;gap:12px}
.lh-chuyen a{display:flex;flex-direction:column;justify-content:center;min-height:92px;padding:16px 18px;border:1px solid rgba(27,23,20,.16);border-radius:16px;transition:border-color .2s ease-out,background-color .2s ease-out}
.lh-chuyen a:hover{border-color:rgba(27,23,20,.45)}
.lh-chuyen a.sau{background:var(--chu-kem);color:var(--kem);border-color:var(--chu-kem);text-align:right;align-items:flex-end}
.lh-chuyen a.sau:hover{background:#000}
.lh-chuyen a.mot{grid-column:1/-1}
.lh-chuyen small{display:flex;align-items:center;gap:8px;font-size:12.5px;font-weight:600;letter-spacing:.14em;text-transform:uppercase;color:#6B6157}
.lh-chuyen a.sau small{color:#ADA396}
.lh-chuyen small svg{width:16px;height:16px}
.lh-chuyen b{display:block;margin-top:6px;font-family:var(--serif);font-weight:600;font-size:21px;line-height:1.2;letter-spacing:-.01em;text-wrap:pretty}
.than .lh-ds-kem{margin-top:22px;border-top:1px solid rgba(27,23,20,.14)}
.lh-ds-kem li{border-bottom:1px solid rgba(27,23,20,.14)}
.lh-ds-kem a{display:grid;grid-template-columns:34px 1fr;column-gap:12px;align-items:baseline;padding:13px 0;font-size:17.5px;line-height:1.4}
.lh-ds-kem i{font-family:var(--serif);font-style:italic;font-weight:500;font-size:21px;color:var(--nhan-kem);line-height:1}
.lh-ds-kem a:hover{color:#000}
.than a.chu{border-bottom:1.5px solid rgba(27,23,20,.3);font-weight:600;transition:border-color .2s ease-out}
.than a.chu:hover{border-bottom-color:var(--chu-kem)}
.than .o-chep pre.thuong{font-size:16px;line-height:1.62}

/* ---------- thẻ thu gọn cho trang chủ ---------- */
.lh-gon{display:grid;grid-template-columns:repeat(4,1fr);gap:clamp(14px,1.7vw,22px)}
.lh-gon .lh-the h3.tit{font-size:clamp(1.3rem,1.75vw,1.45rem)}
.lh-gon .lh-the-than{padding:18px 18px 8px}

/* ---------- thu nhỏ ---------- */
@media (max-width:1099px){
  .lh-kq{grid-template-columns:1fr 1fr}
  .lh-gon{grid-template-columns:1fr 1fr}
  .lh-luoi{grid-template-columns:1fr 1fr}
  .lh-luoi>li:last-child:nth-child(even){grid-column:1/-1}
}
@media (max-width:900px){
  .lh-dau .khung{grid-template-columns:1fr}
  .lh-dau-bia{max-width:520px}
  .lh-the.lon{flex-direction:column}
  .lh-the.lon .lh-bia{width:100%;aspect-ratio:16/10;min-height:0;border-right:0;border-bottom:1px solid var(--vach)}
  .lh-hai,.lh-khoi>li,.lh-nguoi{grid-template-columns:1fr}
  .lh-nguoi img{max-width:300px}
  .lh-buoc>li{grid-template-columns:52px 1fr}
  .lh-buoc>li>i{font-size:30px}
  .lh-hoi summary{font-size:17px}
  .lh-hoi details p{padding-right:0}
  .lh-keu .nut,.lh-dau .hang-nut .nut{width:100%;flex:none}
  .lh-viec{padding:20px 20px 8px}
  .lh-viec ol li{font-size:17px;padding-left:38px}
}
@media (max-width:599px){
  .lh-luoi,.lh-kq,.lh-gon{grid-template-columns:1fr}
  .lh-bai{grid-template-columns:32px 1fr 18px;column-gap:12px}
  div.lh-bai{grid-template-columns:32px 1fr}
  .lh-bai>i{font-size:23px}
  .lh-bai>em{grid-column:2;grid-row:2;margin-top:6px}
  .lh-bai>svg{grid-column:3;grid-row:1}
  .lh-chuyen{grid-template-columns:1fr}
  .lh-chuyen a.sau{order:-1}
  .lh-tien span.thanh{max-width:none}
}

/* ---------- giảm chuyển động ---------- */
@media (prefers-reduced-motion:reduce){
  .lh-the,.lh-bia svg,.lh-bai>svg,.lh-hoi summary::after,.lh-chuyen a{transition:none}
  .lh-the:hover,.lh-the:hover .lh-bia svg,a.lh-bai:hover>svg{transform:none}
  .lh-dau-bia{animation:none}
}