:root{--brand:#0f5c4d;--accent:#ff6a3d;--ink:#16211e;--muted:#5d6b67;--line:#e4e9e7;--bg:#f7f9f8;--card:#fff;--radius:14px;--shadow:0 1px 2px rgba(16,33,30,.06),0 8px 24px rgba(16,33,30,.06)}
*{box-sizing:border-box}html{overflow-x:hidden;max-width:100%;-webkit-text-size-adjust:100%}
body{margin:0;font-family:"Be Vietnam Pro",system-ui,-apple-system,"Segoe UI",Roboto,Arial,sans-serif;color:var(--ink);background:var(--bg);line-height:1.6;font-size:16px;overflow-x:hidden}
img{max-width:100%;display:block}a{color:var(--brand)}h1,h2,h3{line-height:1.25;margin:0 0 .5em;letter-spacing:-.01em}
h1{font-size:clamp(1.6rem,3.6vw,2.4rem);font-weight:800}h2{font-size:1.35rem}h3{font-size:1.05rem}
.wrap{max-width:1160px;margin:0 auto;padding:0 20px}.narrow{max-width:720px}.sec{padding:36px 20px 64px}
.muted{color:var(--muted)}.small{font-size:.875rem}.center{text-align:center}.err{color:#c0352b}.ok{color:#15803d}
.h-sec{margin:40px 0 16px}

.top{background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:30}
.top-in{display:flex;align-items:center;justify-content:space-between;height:64px;gap:12px}
.logo{text-decoration:none;color:var(--brand);font-weight:800;font-size:1.15rem;display:flex;align-items:center;min-width:0}
.logo img{height:38px;width:auto}.logo-text{white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.nav{display:flex;align-items:center;gap:6px;flex:0 0 auto}
.nav-link{text-decoration:none;color:var(--ink);font-weight:500;padding:8px 12px;border-radius:8px;font-size:.95rem;white-space:nowrap}
.nav-link:hover{background:var(--bg)}
.umenu{position:relative}.umenu summary{list-style:none;cursor:pointer;display:flex}.umenu summary::-webkit-details-marker{display:none}
.umenu summary img,.ava{width:38px;height:38px;border-radius:50%;object-fit:cover}
.ava{background:var(--brand);color:#fff;display:grid;place-items:center;font-weight:700}
.umenu-box{position:absolute;right:0;top:48px;background:#fff;border:1px solid var(--line);border-radius:12px;box-shadow:var(--shadow);min-width:230px;padding:10px;display:grid;gap:2px}
.umenu-name{font-weight:700;padding:4px 10px 0}.umenu-code{font-size:.8rem;color:var(--muted);padding:0 10px 8px;border-bottom:1px solid var(--line);margin-bottom:6px}
.umenu-box a,.umenu-box button{all:unset;cursor:pointer;padding:8px 10px;border-radius:8px;font-size:.95rem}.umenu-box a:hover,.umenu-box button:hover{background:var(--bg)}

.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;background:var(--brand);color:#fff;border:0;border-radius:10px;padding:11px 20px;font:inherit;font-weight:600;cursor:pointer;text-decoration:none;transition:filter .15s,transform .05s;white-space:nowrap}
.btn:hover{filter:brightness(1.08)}.btn:active{transform:translateY(1px)}.btn:disabled{opacity:.6;cursor:wait}
.btn-accent{background:var(--accent)}.btn-ghost{background:#fff;color:var(--ink);border:1px solid var(--line)}
.btn-sm{padding:8px 14px;font-size:.9rem}.btn-lg{padding:15px 26px;font-size:1.05rem;border-radius:12px}.btn-block{display:flex;width:100%}
.btn-danger{background:#fff;color:#c0352b;border:1px solid #f1c9c5}

.hero{background:linear-gradient(135deg,var(--brand),color-mix(in srgb,var(--brand) 70%,#000));color:#fff;padding:56px 0 64px;text-align:center}
.hero p{max-width:640px;margin:0 auto 26px;opacity:.92;font-size:1.05rem}
.search{display:flex;gap:8px;max-width:520px;margin:0 auto}
.search input{flex:1;min-width:0;border:0;border-radius:10px;padding:13px 16px;font:inherit}
.search .btn{background:var(--accent)}
.chips{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:24px}
.chip{padding:8px 16px;border-radius:999px;background:#fff;border:1px solid var(--line);text-decoration:none;color:var(--ink);font-weight:500;font-size:.92rem}
.chip.on{background:var(--brand);border-color:var(--brand);color:#fff}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(270px,1fr));gap:22px}
.card{background:var(--card);border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow);text-decoration:none;color:inherit;display:flex;flex-direction:column;transition:transform .15s}
.card:hover{transform:translateY(-3px)}
.card-cover{position:relative;aspect-ratio:16/9;background:#dfe7e4;overflow:hidden}.card-cover img{width:100%;height:100%;object-fit:cover}
.cover-ph{width:100%;height:100%;display:grid;place-items:center;padding:18px;text-align:center;background:linear-gradient(135deg,var(--brand),color-mix(in srgb,var(--brand) 55%,var(--accent)));color:#fff;font-weight:700;font-size:1.05rem}
.badge{position:absolute;top:10px;left:10px;background:#15803d;color:#fff;font-size:.75rem;font-weight:700;padding:4px 10px;border-radius:999px}.badge.draft{background:#92400e;left:auto;right:10px}
.card-body{padding:16px 18px 18px;display:flex;flex-direction:column;gap:6px;flex:1}
.card-cat{color:var(--accent);font-size:.78rem;font-weight:700;text-transform:uppercase;letter-spacing:.05em}
.card-body h3{margin:0}.card-body p{margin:0;color:var(--muted);font-size:.92rem;display:-webkit-box;-webkit-line-clamp:3;-webkit-box-orient:vertical;overflow:hidden}
.card-foot{display:flex;justify-content:space-between;align-items:center;margin-top:auto;padding-top:12px;gap:8px}
.meta{color:var(--muted);font-size:.85rem}.price b{font-size:1.05rem;color:var(--brand)}.price s{color:var(--muted);font-size:.85rem}
.empty{background:#fff;border:1px dashed var(--line);border-radius:var(--radius);padding:40px 20px;text-align:center;color:var(--muted)}
.panel{background:#fff;border-radius:var(--radius);box-shadow:var(--shadow);padding:28px}
.notice{background:#fff7e6;border:1px solid #f5dfa8;color:#6b4e00;border-radius:10px;padding:10px 14px;font-size:.92rem;margin:10px 0}
.okbox{background:#ecfdf3;border:1px solid #a7e3bf;border-radius:10px;padding:14px}

.c-hero{background:linear-gradient(135deg,var(--brand),color-mix(in srgb,var(--brand) 70%,#000));color:#fff;padding:44px 0}
.c-hero-in{display:grid;grid-template-columns:1fr 380px;gap:40px;align-items:start}
.c-hero .card-cat{color:#ffd9cc}.lead{font-size:1.1rem;opacity:.93;margin:0 0 18px}
.c-stats{display:flex;flex-wrap:wrap;gap:8px}.c-stats span{background:rgba(255,255,255,.14);padding:6px 12px;border-radius:999px;font-size:.85rem}
.buybox{background:#fff;color:var(--ink);border-radius:var(--radius);box-shadow:0 20px 50px rgba(0,0,0,.25);padding:14px;margin-bottom:-120px;position:relative;z-index:2}
.c-cover{aspect-ratio:16/9;border-radius:10px;overflow:hidden;background:#dfe7e4}.c-cover img{width:100%;height:100%;object-fit:cover}
.buy-price{padding:14px 6px 10px}.buy-price b{font-size:1.7rem;color:var(--brand)}.buy-price s{color:var(--muted)}
.buy-list{list-style:none;margin:14px 6px 6px;padding:0;font-size:.9rem;color:var(--muted);display:grid;gap:6px}.buy-list li::before{content:"✓ ";color:#15803d;font-weight:700}
.c-main{padding:36px 20px 80px}.c-col{max-width:720px}
.prose{font-size:1.02rem}.prose h2,.prose h3,.prose h4{margin-top:1.4em}.prose img{border-radius:10px;margin:14px 0}.prose blockquote{border-left:4px solid var(--accent);margin:1em 0;padding:6px 16px;background:#fff;border-radius:0 10px 10px 0}
.ymyl{margin-top:32px;font-size:.85rem;color:var(--muted);border-top:1px solid var(--line);padding-top:16px}
.buybar{display:none}

.curri{display:grid;gap:10px}
.chap{background:#fff;border:1px solid var(--line);border-radius:12px;overflow:hidden}
.chap summary{cursor:pointer;padding:14px 16px;font-weight:700;display:flex;justify-content:space-between;gap:10px;list-style:none}.chap summary::-webkit-details-marker{display:none}
.chap summary em{font-style:normal;font-weight:500;color:var(--muted);font-size:.85rem;white-space:nowrap}
.lesson{display:flex;align-items:center;gap:10px;padding:11px 16px;border-top:1px solid var(--line);text-decoration:none;color:var(--ink);font-size:.95rem}
a.lesson:hover{background:var(--bg)}.lesson.cur{background:color-mix(in srgb,var(--brand) 10%,#fff);font-weight:600}
.l-title{flex:1;min-width:0}.l-min{color:var(--muted);font-size:.8rem;white-space:nowrap}
.ic{font-style:normal;width:22px;height:22px;flex:0 0 22px;display:grid;place-items:center;font-size:.7rem;border-radius:50%}
.ic.play{background:color-mix(in srgb,var(--brand) 14%,#fff);color:var(--brand)}.ic.ok{background:#15803d;color:#fff;font-size:.8rem}.ic.lock{font-size:.85rem}

.video{position:relative;aspect-ratio:16/9;background:#000;border-radius:12px;overflow:hidden}
.video iframe,.video video{position:absolute;inset:0;width:100%;height:100%;border:0}
.wm{position:absolute;color:rgba(255,255,255,.34);font-size:.8rem;font-weight:600;pointer-events:none;text-shadow:0 0 3px rgba(0,0,0,.5);transition:left 2s,top 2s;white-space:nowrap;z-index:3}

.g-wrap{display:flex;justify-content:center;margin:22px 0;min-height:44px}
.dev-login{display:grid;gap:10px;max-width:320px;margin:18px auto}
input,select,textarea{font:inherit;border:1px solid #cfd8d5;border-radius:10px;padding:11px 13px;width:100%;background:#fff;color:var(--ink)}
input:focus,select:focus,textarea:focus{outline:2px solid color-mix(in srgb,var(--brand) 40%,#fff);border-color:var(--brand)}
input:disabled{background:var(--bg);color:var(--muted)}
.fld{display:grid;gap:6px;margin:14px 0}.fld>span{font-weight:600;font-size:.9rem}.row{display:flex;gap:8px}.row>*{min-width:0}
.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:4px 18px}.form-grid>div{grid-column:1/-1}
.sum{display:flex;gap:14px;align-items:center;border:1px solid var(--line);border-radius:12px;padding:12px;margin:16px 0}.sum-cover{width:120px;flex:0 0 120px;aspect-ratio:16/9;border-radius:8px;overflow:hidden;font-size:.6rem}.sum-cover img{width:100%;height:100%;object-fit:cover}.sum h3,.sum p{margin:0}
.total{display:flex;justify-content:space-between;align-items:center;border-top:1px solid var(--line);margin-top:18px;padding:16px 0 6px;font-size:1.05rem}.total b{font-size:1.5rem;color:var(--brand)}
.pay{display:grid;grid-template-columns:280px 1fr;gap:24px;margin:20px 0;align-items:start}
.pay-qr{text-align:center}.pay-qr img{margin:0 auto;border:1px solid var(--line);border-radius:12px}
.pay-row{display:flex;align-items:center;gap:10px;padding:10px 0;border-bottom:1px solid var(--line)}.pay-row span{color:var(--muted);font-size:.88rem;width:110px;flex:0 0 110px}.pay-row b{flex:1;word-break:break-all}
.copy{border:1px solid var(--line);background:#fff;border-radius:8px;padding:5px 10px;font:inherit;font-size:.8rem;cursor:pointer}
.waiting{display:flex;align-items:center;gap:10px;background:var(--bg);border-radius:10px;padding:12px 14px;font-size:.92rem;margin:12px 0}
.spin{width:16px;height:16px;border:2px solid var(--line);border-top-color:var(--brand);border-radius:50%;animation:sp 1s linear infinite;flex:0 0 16px}@keyframes sp{to{transform:rotate(360deg)}}

.learn{display:grid;grid-template-columns:340px 1fr;min-height:calc(100vh - 64px)}
.side{background:#fff;border-right:1px solid var(--line);padding:16px;position:sticky;top:64px;height:calc(100vh - 64px);overflow-y:auto}
.side-back{display:block;font-weight:700;text-decoration:none;color:var(--ink);margin-bottom:12px}
.bar{height:8px;background:var(--line);border-radius:99px;overflow:hidden}.bar div{height:100%;background:#15803d;border-radius:99px}
.bar-txt{font-size:.8rem;color:var(--muted);margin:6px 0 14px}
.side .chap{border-radius:10px}.side .lesson{font-size:.88rem;padding:9px 12px}
.stage{padding:24px clamp(16px,4vw,48px) 80px;max-width:1040px;width:100%;margin:0 auto}
.side-toggle{display:none;margin-bottom:12px}
.l-h1{font-size:1.5rem;margin:22px 0 12px}
.l-nav{display:flex;justify-content:space-between;gap:10px;margin-top:32px;padding-top:20px;border-top:1px solid var(--line);flex-wrap:wrap}
.files{margin-top:24px;display:grid;gap:8px}.files h3{margin:0}.files a{background:#fff;border:1px solid var(--line);border-radius:10px;padding:10px 14px;text-decoration:none;font-weight:500}

.tbl-wrap{overflow-x:auto;background:#fff;border-radius:var(--radius);box-shadow:var(--shadow)}
.tbl{width:100%;border-collapse:collapse;font-size:.92rem}.tbl th,.tbl td{text-align:left;padding:12px 14px;border-bottom:1px solid var(--line);vertical-align:top}.tbl th{font-size:.8rem;color:var(--muted);text-transform:uppercase;letter-spacing:.04em;white-space:nowrap}
.st{font-size:.78rem;font-weight:700;padding:3px 10px;border-radius:999px;white-space:nowrap}.st-paid,.st-published{background:#dcfce7;color:#166534}.st-pending,.st-draft{background:#fef3c7;color:#92400e}.st-cancelled,.st-archived{background:#eee;color:#555}

.foot{background:#10201c;color:#c7d3cf;padding:36px 0;font-size:.9rem}.foot a{color:#fff}.foot-name{font-weight:800;color:#fff;font-size:1.1rem;margin-bottom:8px}.foot-note{max-width:760px;opacity:.8;font-size:.82rem}.foot-copy{opacity:.6;margin:8px 0 0}

@media(max-width:900px){
  .c-hero-in{grid-template-columns:1fr;gap:24px}.buybox{margin-bottom:0}
  .buybar{display:flex;position:fixed;left:0;right:0;bottom:0;background:#fff;border-top:1px solid var(--line);padding:10px 16px;justify-content:space-between;align-items:center;gap:12px;z-index:40;box-shadow:0 -6px 20px rgba(0,0,0,.08)}
  .buybar .btn-lg{padding:12px 18px;font-size:.98rem}
  .learn{grid-template-columns:1fr}.side{position:fixed;left:0;top:64px;bottom:0;width:min(88vw,340px);height:auto;z-index:25;transform:translateX(-102%);transition:transform .2s;box-shadow:var(--shadow)}.side.open{transform:none}
  .side-toggle{display:inline-flex}
  .pay{grid-template-columns:1fr}.form-grid{grid-template-columns:1fr}
}
@media(max-width:560px){.nav-link{display:none}.nav .btn,.umenu{display:flex}.top-in{height:58px}.hero{padding:40px 0 46px}.panel{padding:20px}.sec{padding:24px 16px 56px}.l-nav .btn{flex:1}}

/* Trang khoa: khoi tom tat, giang vien, nut cuoi trang (theo TIEU-CHUAN-hoc-long-vn.md) */
.h-row{display:flex;justify-content:space-between;align-items:center;gap:12px;margin:40px 0 16px}.h-row .h-sec{margin:0}
.c-sum{display:grid;grid-template-columns:repeat(auto-fit,minmax(130px,1fr));gap:12px;margin-top:20px;background:#fff;border:1px solid var(--line);border-radius:12px;padding:18px}
.c-sum div{text-align:center}.c-sum b{display:block;font-size:1.3rem;color:var(--brand)}.c-sum span{color:var(--muted);font-size:.85rem}
.teacher{display:flex;gap:18px;align-items:flex-start;background:#fff;border:1px solid var(--line);border-radius:12px;padding:20px}
.teacher img,.teacher .ava{width:84px;height:84px;flex:0 0 84px;border-radius:50%;object-fit:cover;font-size:1.8rem}.teacher h3{margin:0}.teacher p{margin:2px 0 8px}.teacher .prose{font-size:.95rem}
.c-end{margin-top:36px;text-align:center;background:color-mix(in srgb,var(--brand) 8%,#fff);border-radius:var(--radius);padding:32px 20px}.c-end h2{margin-bottom:16px}
.buy-own{padding:14px 6px 12px;display:grid;gap:8px}.buy-alt{display:block;text-align:center;font-size:.88rem;margin-top:10px}
.l-top{display:flex;align-items:center;gap:12px;margin-bottom:12px;flex-wrap:wrap}.l-top .side-toggle{margin:0}.l-pos{color:var(--muted);font-size:.88rem}
.stage .okbox{margin-bottom:16px}.empty .btn{margin-top:8px}
@media(max-width:560px){.teacher{flex-direction:column;align-items:center;text-align:center}}

/* ===== TONG TRANG, SACH (hoc theo hoc.long.vn, 19/09): nen trang, tieu de chu co chan, the phang, mot mau nhan ===== */
:root{--bg:#fff;--ink:#1e242a;--muted:#6b7177;--line:#e6e6e6;--radius:4px;--shadow:0 1px 3px rgba(0,0,0,.08),0 4px 14px rgba(0,0,0,.05);--serif:"Noto Serif","Times New Roman",serif}
body{background:#fff;color:#505050;font-size:17px;line-height:1.65}
h1,h2,h3{font-family:var(--serif);font-weight:400;color:var(--ink);letter-spacing:0}
h1{font-size:clamp(1.8rem,3.4vw,2.5rem);font-weight:400}h2{font-size:1.6rem}h3{font-size:1.15rem}
a{color:var(--accent)}
.top{border-bottom:0;box-shadow:0 2px 8px rgba(0,0,0,.05)}.top-in{height:72px}
.logo{color:var(--ink);font-family:var(--serif);font-weight:500;font-size:1.2rem}.logo img{height:40px}
.nav{gap:18px}.nav-link{font-weight:400;color:var(--ink);padding:6px 4px;border-radius:0}.nav-link:hover{background:none;color:var(--accent)}
.btn{border-radius:3px;font-weight:500;padding:11px 22px;background:var(--ink)}.btn-accent{background:var(--accent)}.btn-lg{border-radius:3px;padding:14px 28px;font-size:1rem}
.btn-ghost{background:#fff;color:var(--ink)}
.linkbtn{all:unset;cursor:pointer;color:var(--accent);font-size:.95rem;text-decoration:none}.linkbtn:hover{text-decoration:underline}.linkbtn.more{display:inline-block;margin-top:18px}.linkbtn.big{font-size:1.05rem}
.sec{padding:56px 20px 80px}
.cat-head{display:flex;justify-content:space-between;align-items:center;gap:20px;flex-wrap:wrap;margin-bottom:22px}.cat-head h1{margin:0;color:var(--ink)}
.search{margin:0;max-width:none;width:min(100%,360px);border:1px solid #cfcfcf;border-radius:3px;gap:0;background:#fff}
.search input{border:0;border-radius:0;padding:11px 12px;font-size:.95rem;background:transparent}.search input:focus{outline:none}
.search button{all:unset;cursor:pointer;display:grid;place-items:center;padding:0 12px;color:var(--ink)}
.tabs{display:flex;gap:32px;flex-wrap:wrap;margin-bottom:40px}
.tab{text-decoration:none;color:var(--ink);font-size:.98rem;padding-bottom:3px;border-bottom:1px solid transparent}.tab:hover{color:var(--accent)}.tab.on{color:var(--accent);border-bottom-color:var(--accent)}
.grid{grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:34px}
.card{border-radius:4px;box-shadow:0 1px 4px rgba(0,0,0,.12)}.card:hover{transform:none;box-shadow:0 4px 18px rgba(0,0,0,.14)}
.card-cover{background:#f3f3f3}.cover-ph{background:#f3f1ee;color:var(--ink);font-family:var(--serif);font-weight:400}
.card-body{padding:16px 16px 18px;gap:4px}.card-body h3{font-size:1.15rem;line-height:1.35}
.card-type{font-size:.78rem;color:var(--muted);margin-bottom:6px}
.card-body p{font-size:.95rem;color:#505050}
.card-price{margin-top:auto;padding-top:14px;font-family:var(--serif);color:var(--ink)}.card-price b{font-weight:400;font-size:1.1rem}.card-price s{color:var(--muted);font-size:.85rem;margin-right:4px}
.badge{border-radius:3px;font-weight:500}.badge.own{background:var(--ink)}
.empty{border-radius:4px}.panel{border-radius:4px}

.c-top{padding:96px 0 84px;text-align:center}.narrow2{max-width:900px}
.c-top h1{font-size:clamp(2rem,4vw,2.8rem);margin-bottom:.45em}.c-top .lead{font-size:1.12rem;color:var(--ink);opacity:1;margin:0 auto 28px;max-width:820px}
.c-top .btn{font-size:.9rem;padding:12px 20px}.c-top .buy-alt{margin-top:14px;font-size:.9rem}
.c-desc{max-width:820px;padding-bottom:40px}.prose{font-size:1.02rem}.prose blockquote{border-left:3px solid var(--accent);background:#faf8f6;border-radius:0}
.c-main{padding:0 20px 72px}.c-main .h-row{margin:0 0 26px}.h-sec{font-size:1.7rem}
.c-grid{display:grid;grid-template-columns:minmax(0,1fr) 420px;gap:48px;align-items:start}.c-col{max-width:none}
.curri{gap:0}.curri:not(.all) .chap:nth-child(n+7){display:none}
.chap{border:0;border-bottom:1px solid #8a8a8a;border-radius:0;background:none}
.chap summary{font-weight:400;color:var(--ink);padding:22px 24px;align-items:center}
.chap summary em{margin-left:auto;padding-right:14px}
.chap summary::after{content:"";width:8px;height:8px;border-right:1.5px solid var(--accent);border-bottom:1.5px solid var(--accent);transform:rotate(45deg);flex:0 0 8px;margin-top:-4px}
.chap[open] summary::after{transform:rotate(-135deg);margin-top:4px}
.lesson{border-top:0;padding:10px 24px 10px 40px;font-size:.98rem}.chap .lesson:last-child{padding-bottom:20px}
.ic.play{background:none;color:var(--accent)}.ic.ok{background:var(--accent)}
.lesson.cur{background:#faf6f3}
.infobox{background:#fff;border-radius:4px;box-shadow:0 2px 10px rgba(0,0,0,.14);overflow:hidden;position:sticky;top:96px}
.infobox .c-cover,.infobox .video{border-radius:0}
.info-in{padding:26px 26px 22px}.info-in h3{font-size:1.2rem;margin:0 0 12px}.rule{display:block;width:30px;height:1px;background:var(--ink);margin-bottom:16px}
.info-list{list-style:none;margin:0;padding:0;display:grid;gap:12px}.info-list li{display:flex;align-items:center;gap:12px;color:var(--ink)}
.info-list svg{width:20px;height:20px;flex:0 0 20px;color:var(--accent);fill:var(--accent)}.info-list svg[fill=none]{fill:none}
.info-list b{font-weight:400}.info-list s{color:var(--muted);font-size:.9rem;margin-right:6px}
.buy-own{padding:0 0 16px}
.teacher{border-radius:4px;margin-top:0}.c-col .h-sec{margin-top:56px}
.c-band{background:#f5f5f5;padding:96px 0}.c-band-in{display:flex;justify-content:space-between;align-items:center;gap:32px;flex-wrap:wrap}
.c-band h2{font-size:clamp(1.7rem,3.4vw,2.5rem);margin:0;max-width:560px;line-height:1.3}
.ymyl{border-top:0;margin:28px 0 0;font-size:.8rem}
.foot{background:#fff;color:var(--muted);padding:0 0 28px;font-size:.85rem}.foot .wrap{border-top:1px solid var(--line);padding-top:22px}
.foot a{color:var(--accent)}.foot-name{display:none}.foot-note{opacity:1;font-size:.8rem;max-width:none;margin:0 0 6px}.foot-copy{opacity:1;margin:6px 0 0}
.side{top:72px;height:calc(100vh - 72px)}.learn{min-height:calc(100vh - 72px)}.bar div{background:var(--accent)}
.side .chap summary{padding:14px 12px}.side .lesson{padding:9px 12px 9px 22px}
input,select,textarea{border-radius:3px}.okbox,.notice,.sum,.waiting,.copy,.files a,.umenu-box,.tbl-wrap{border-radius:4px}
@media(max-width:900px){.c-grid{grid-template-columns:1fr;gap:28px}.infobox{position:static;order:-1}.c-top{padding:56px 0 48px}.c-band{padding:56px 0}.side{top:72px}}
@media(max-width:560px){.nav-link{display:inline}.nav{gap:12px}.nav-link{font-size:.88rem}.top-in{height:64px}.tabs{gap:20px}.grid{gap:22px}}

/* Trang Khoa hoc cua toi, theo hoc.long.vn/enrollments: the to, vong tron tien do, hai nut */
.my-bar{display:flex;justify-content:space-between;align-items:center;gap:16px;flex-wrap:wrap;margin:0 0 32px}.my-bar select{width:auto;border:0;background:transparent;font-size:1rem;color:var(--ink);padding:6px 4px;cursor:pointer}.my-bar .meta{flex:1}
.mygrid{display:grid;grid-template-columns:repeat(auto-fill,minmax(320px,1fr));gap:36px}
.mycard{position:relative;background:#fff;border-radius:4px;box-shadow:0 1px 4px rgba(0,0,0,.14);display:flex;flex-direction:column;overflow:hidden}.mycard[hidden]{display:none}
.mycard-cover{display:block;position:relative;aspect-ratio:16/9;background:#f3f1ee;overflow:hidden}.mycard-cover img{width:100%;height:100%;object-fit:cover}
.ring{position:relative;width:64px;height:64px;margin:-32px auto 0;display:grid;place-items:center;background:#fff;border-radius:50%;box-shadow:0 1px 4px rgba(0,0,0,.12);z-index:2}
.ring svg{position:absolute;inset:0;width:100%;height:100%}.ring-bg{fill:none;stroke:#eee;stroke-width:3}.ring-fg{fill:none;stroke:var(--accent);stroke-width:3;stroke-linecap:round}
.ring b{position:relative;font-family:var(--serif);font-weight:400;font-size:.9rem;color:var(--accent)}
.mycard-body{padding:14px 22px 26px;text-align:center;flex:1}.mycard-body h3{font-size:1.45rem;line-height:1.3;margin:0 0 6px}.mycard-body h3 a{color:var(--ink);text-decoration:none}.mycard-body h3 a:hover{color:var(--accent)}
.mycard-act{display:grid;grid-template-columns:1fr 1fr;border-top:1px solid var(--line)}
.mycard-act a{display:flex;flex-direction:column;align-items:center;gap:6px;padding:18px 8px;text-decoration:none;color:var(--ink);font-weight:600;font-size:.95rem;text-align:center}
.mycard-act a+a{border-left:1px solid var(--line)}.mycard-act a:hover{background:#faf8f6;color:var(--accent)}.mycard-act svg{width:20px;height:20px}
@media(max-width:560px){.mygrid{grid-template-columns:1fr;gap:24px}.mycard-body h3{font-size:1.25rem}}
.mycard-cover,.mycard-cover .cover-ph{text-decoration:none;color:var(--ink)}

/* PHONG HOC (theo hoc.long.vn): chi de hoc, nen toi, cot trai muc luc, ben phai bai hoc. Tong quan nam o trang /khoa */
body.player{background:#1b1b1b;color:#e9e9e9;font-size:16px}
.p-wrap{display:grid;grid-template-columns:400px 1fr;min-height:100vh}
body.wide .p-wrap{grid-template-columns:1fr}body.wide .p-side{display:none}
.p-side{background:#242424;height:100vh;position:sticky;top:0;overflow-y:auto;display:flex;flex-direction:column;padding:14px 16px 24px}
.p-cover{background:var(--accent);border-radius:3px 3px 0 0;height:66px;display:grid;place-items:center;overflow:hidden}.p-cover img{height:50px;width:auto;border-radius:2px}
.p-head{background:#1d1d1d;padding:18px 18px 16px;border-radius:0 0 3px 3px;box-shadow:0 2px 8px rgba(0,0,0,.35)}
.p-back{color:#cfcfcf;text-decoration:none;font-size:.85rem}.p-back:hover{color:#fff}
.p-head h2{color:#fff;font-family:"Be Vietnam Pro",sans-serif;font-weight:700;font-size:1.45rem;line-height:1.35;margin:10px 0 16px}
.p-bar{height:4px;background:#4a4a4a;border-radius:9px;overflow:hidden}.p-bar div{height:100%;background:var(--accent)}
.p-pct{margin:10px 0 0;font-size:.95rem;color:#e9e9e9}
.p-jump{margin:16px 0 8px;background:#242424;color:#e9e9e9;border:1px solid #555;border-radius:3px;padding:12px}
.p-chap{border-bottom:1px solid #3a3a3a}
.p-chap summary{list-style:none;cursor:pointer;display:flex;align-items:center;gap:14px;padding:18px 4px;color:#fff;font-weight:600}.p-chap summary::-webkit-details-marker{display:none}
.p-chap summary span{flex:1}.p-chap summary em{font-style:normal;font-weight:400;color:#cfcfcf;font-size:.9rem}
.p-chap summary::after{content:"";width:7px;height:7px;border-right:1.5px solid #cfcfcf;border-bottom:1.5px solid #cfcfcf;transform:rotate(45deg);margin:-3px 6px 0 4px}.p-chap[open] summary::after{transform:rotate(-135deg);margin-top:4px}
.p-check{width:24px;height:24px;flex:0 0 24px;border-radius:50%;border:2px solid #8a8a8a;display:grid;place-items:center}
.p-chap.ok .p-check{background:var(--accent);border-color:var(--accent)}.p-chap.ok .p-check::after{content:"✓";color:#fff;font-size:.8rem;font-style:normal;font-weight:700}
.p-lesson{display:flex;gap:14px;align-items:flex-start;padding:12px 8px 12px 10px;text-decoration:none;color:#dcdcdc;border-left:1px solid #4a4a4a;margin-left:15px}
.p-lesson:hover{background:#2e2e2e}.p-lesson.cur{background:#333;color:#fff}
.p-lesson b{display:block;font-weight:500;font-size:.95rem;line-height:1.4}.p-lesson em{display:block;font-style:normal;font-size:.72rem;color:#a9a9a9;letter-spacing:.04em;margin-top:4px}
.p-dot{width:14px;height:14px;flex:0 0 14px;border-radius:50%;border:2px solid #8a8a8a;margin:3px 0 0 -18px;background:#242424}
.p-lesson.ok .p-dot{background:var(--accent);border-color:var(--accent)}.p-lesson.cur .p-dot{border-color:var(--accent)}
.p-over{margin-top:22px;color:#cfcfcf;font-size:.88rem;text-align:center}.p-over:hover{color:#fff}
.p-main{display:flex;flex-direction:column;min-width:0;min-height:100vh}
.p-top{display:flex;align-items:center;gap:12px;background:#242424;padding:14px 22px;border-bottom:1px solid #333}
.p-top h1{flex:1;margin:0;color:#fff;font-family:"Be Vietnam Pro",sans-serif;font-weight:600;font-size:1.05rem;line-height:1.4}
.p-wide,.p-menu{all:unset;cursor:pointer;color:#e9e9e9;width:30px;height:30px;display:grid;place-items:center}.p-wide svg{width:20px;height:20px}.p-menu{display:none;font-size:1.2rem}
.p-stage{flex:1;padding:26px 0 40px;width:100%;max-width:1320px;margin:0 auto}
.p-stage .video{border-radius:0}.p-empty,.p-done{margin:0 22px 18px;padding:16px 18px;background:#262626;border:1px solid #3a3a3a;border-radius:3px;color:#dcdcdc}
.p-prose{padding:22px;color:#e4e4e4;max-width:900px}.p-prose h2,.p-prose h3,.p-prose h4,.p-prose b,.p-prose strong{color:#fff}.p-prose a{color:#f0a58f}
body.player .prose blockquote{background:#262626;color:#e4e4e4}
.p-files{padding:0 22px}.p-files h3{color:#fff}.p-files a{background:#262626;border-color:#3a3a3a;color:#e9e9e9}
.p-foot{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:16px 22px;border-top:1px solid #333;background:#1f1f1f;position:sticky;bottom:0}
.p-prev{color:#cfcfcf;text-decoration:none;font-size:.9rem;min-width:90px}.p-prev:last-child{text-align:right}.p-prev:hover{color:#fff}
.p-next{all:unset;cursor:pointer;background:var(--accent);color:#fff;font-weight:700;font-size:.82rem;letter-spacing:.04em;padding:13px 22px;border-radius:3px;text-align:center}.p-next:hover{filter:brightness(1.1)}.p-next.was{background:#3a3a3a;color:#dcdcdc}.p-next:disabled{opacity:.6;cursor:wait}
@media(max-width:900px){.p-wrap{grid-template-columns:1fr}.p-menu{display:grid}.p-wide{display:none}
  .p-side{position:fixed;left:0;top:0;bottom:0;width:min(90vw,400px);z-index:40;transform:translateX(-102%);transition:transform .2s;box-shadow:0 0 40px rgba(0,0,0,.6)}.p-side.open{transform:none}
  .p-stage{padding-top:0}.p-foot{padding:12px 14px}.p-prev{min-width:0;font-size:.82rem}.p-next{padding:12px 14px;font-size:.76rem}}
.p-cover{flex:0 0 66px}.p-head,.p-jump{flex:0 0 auto}

/* Dau cot trai phong hoc (sua 20/09): bo dai mau, anh bia phu het be ngang, hang tren co Tro ve + logo nen toi */
.p-side{padding:16px 18px 24px}
.p-brand{flex:0 0 auto;display:flex;justify-content:space-between;align-items:center;gap:12px;margin:2px 2px 14px}.p-brand img{height:22px;width:auto;display:block;opacity:.95}
.p-back{font-size:.92rem}
.p-cover{flex:0 0 auto;height:auto;background:#111;border-radius:6px;display:block;aspect-ratio:16/9;overflow:hidden;box-shadow:0 6px 20px rgba(0,0,0,.45)}
.p-cover img{width:100%;height:100%;object-fit:cover;border-radius:0}
.p-head{background:none;box-shadow:none;padding:18px 2px 4px;border-radius:0}
.p-head h2{font-size:1.2rem;margin:0 0 14px}
.p-jump{margin:14px 0 6px}