/* ===== TRANG HỌC KHÓA AI: giao diện sáng, nền căn phòng 3 chiều, robot Pu ở màn nhập mã ===== */
:root{--ink:#18202e;--mute:#5f6b7e;--dim:#94a0b2;--line:#dbe2ec;--card:rgba(255,255,255,.95);--acc:#e8572a;--acc2:#3b5bdb;--ok:#1f9d68;
  --mono:"JetBrains Mono",ui-monospace,Consolas,monospace}
*{box-sizing:border-box}html,body{margin:0}
/* nền: căn phòng sáng có sàn, trần lưới chạy về chân trời, giữa là mạng nơ-ron 3 chiều */
body{color:var(--ink);font:400 16px/1.6 "Be Vietnam Pro",system-ui,sans-serif;min-height:100vh;overflow-x:hidden;
  background:radial-gradient(60% 26% at 50% 50%,rgba(255,255,255,.55) 0%,rgba(255,255,255,0) 100%) fixed,
    linear-gradient(180deg,#cfd6e1 0%,#dde3ec 38%,#e8ecf2 50%,#d9e0ea 62%,#c4cdda 100%) fixed}
[hidden]{display:none!important}
#net{position:fixed;inset:0;z-index:0}
main,header{position:relative;z-index:1}
.glass{background:var(--card);border:1px solid #fff;border-radius:22px;backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);
  box-shadow:0 1px 0 #fff inset,0 24px 60px -26px rgba(30,45,80,.32)}
.spot{position:relative;isolation:isolate}
.spot::before{content:"";position:absolute;inset:-1px;border-radius:inherit;padding:1.5px;z-index:-1;pointer-events:none;
  background:radial-gradient(240px circle at var(--x,50%) var(--y,50%),rgba(232,87,42,.7),rgba(59,91,219,.45) 45%,transparent 70%);
  -webkit-mask:linear-gradient(#000 0 0) content-box,linear-gradient(#000 0 0);-webkit-mask-composite:xor;mask-composite:exclude;opacity:0;transition:opacity .3s}
.spot:hover::before{opacity:1}
.btn{border:0;border-radius:999px;padding:13px 24px;font:700 15px "Be Vietnam Pro";cursor:pointer;background:var(--ink);color:#fff;transition:.2s}
.btn:hover{background:var(--acc);transform:translateY(-1px);box-shadow:0 10px 24px -8px rgba(232,87,42,.6)}
.btn.line{background:#fff;color:var(--ink);border:1.5px solid var(--line)}
.btn.line:hover{border-color:var(--ink);box-shadow:none}
.btn.ok{background:var(--ok)}
.issue{font-size:13px;font-weight:700;letter-spacing:.14em;text-transform:uppercase;color:var(--acc)}
.kbd{font:700 11px var(--mono);color:var(--mute);border:1px solid var(--line);border-bottom-width:2px;border-radius:6px;padding:2px 6px;background:#fff}

/* ===== 1. Nhập mã ===== */
.login{min-height:100vh;display:grid;grid-template-columns:1fr 1fr;max-width:1240px;margin:0 auto;padding:40px 24px 100px;gap:40px;align-items:center}
/* sân chơi của robot Pu: 3 dòng chữ làm bậc thang */
.stage{position:relative;height:min(560px,76vh);min-height:480px}
.plat{position:absolute;display:flex;gap:10px;align-items:center;background:#fff;border:1px solid #e3e8f0;border-radius:14px;padding:10px 16px 10px 10px;
  font-size:15px;font-weight:700;white-space:nowrap;box-shadow:0 2px 0 #e3e8f0,0 18px 30px -18px rgba(30,45,80,.45)}
.plat i{flex:none;width:30px;height:30px;border-radius:9px;display:grid;place-items:center;font:800 11px var(--mono);font-style:normal;color:#fff;background:var(--ink)}
.plat b{color:var(--acc);margin-left:4px}
.plat small{display:block;font-size:11.5px;font-weight:600;color:var(--ok);line-height:1.2}
.p1{left:3%;bottom:116px}.p2{left:25%;bottom:214px}.p3{left:7%;bottom:312px}
#bot3d{position:absolute;left:0;bottom:0;width:100%;height:calc(100% + 170px);z-index:3;pointer-events:none}
.bubble{position:absolute;left:0;bottom:0;transform:translateX(-50%);max-width:260px;width:max-content;background:#fff;border-radius:16px;padding:9px 14px;font-size:14px;font-weight:600;line-height:1.4;text-align:center;z-index:4;
  box-shadow:0 14px 30px -14px rgba(30,45,80,.45);border:1px solid #e3e8f0;transition:opacity .2s;pointer-events:none}
.bubble::after{content:"";position:absolute;left:var(--tail,50%);bottom:-7px;width:13px;height:13px;background:#fff;border-right:1px solid #e3e8f0;border-bottom:1px solid #e3e8f0;transform:translateX(-50%) rotate(45deg)}
.bubble.out{opacity:0}
.bubble b{color:var(--acc)}
.hearts span{position:absolute;font-size:18px;color:var(--acc);animation:up 1.1s ease-out forwards;z-index:5;pointer-events:none}
@keyframes up{to{transform:translate(var(--dx),-80px) scale(1.3);opacity:0}}
.lgf{padding:38px}
.lgf h1{font:800 clamp(34px,4.2vw,52px)/1.12 "Be Vietnam Pro";margin:14px 0 14px;letter-spacing:-.02em}
.lgf h1 em{color:var(--acc);font-style:normal}
.lgf .lead{font-size:17px;color:var(--mute);margin:0 0 26px}
.field{display:block;font-size:13px;font-weight:700;color:var(--mute);margin-bottom:8px}
.inrow{display:flex;gap:10px;flex-wrap:wrap}
.inrow input{flex:1;min-width:200px;border:1.5px solid var(--line);background:#fff;border-radius:999px;padding:14px 22px;font:700 18px var(--mono);letter-spacing:.12em;text-transform:uppercase;outline:0;color:var(--ink)}
.inrow input:focus{border-color:var(--ink);box-shadow:0 0 0 4px rgba(24,32,46,.08)}
.small{margin-top:14px;font-size:14px;color:var(--mute)}.small b{color:var(--ink)}
.ticks{display:flex;gap:22px;flex-wrap:wrap;margin-top:28px;padding-top:20px;border-top:1px solid var(--line);font-size:14px;color:var(--mute)}
.ticks b{display:block;font-size:26px;font-weight:800;color:var(--ink);line-height:1.3}

/* ===== thanh trên ===== */
.top{display:flex;align-items:center;gap:14px;height:60px;padding:0 20px;position:sticky;top:0;z-index:5;background:rgba(255,255,255,.85);backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);border-bottom:1px solid var(--line)}
.lg{display:flex;align-items:center;gap:10px;font-weight:800;font-size:15px}
.lg i{width:28px;height:28px;border-radius:8px;display:grid;place-items:center;background:var(--ink);color:#fff;font:800 11px var(--mono);font-style:normal}
.sep{color:#c5cdd9}.crumbs{font-size:14px;color:var(--mute)}.crumbs b{color:var(--ink);font-weight:600}
.top .sp{flex:1}
.back{background:#fff;border:1px solid var(--line);border-radius:9px;padding:6px 12px;font:600 13px "Be Vietnam Pro";cursor:pointer;color:var(--ink)}
.back:hover{border-color:var(--ink)}
.search{display:flex;align-items:center;gap:8px;border:1px solid var(--line);background:#fff;border-radius:9px;padding:6px 10px;color:var(--dim);font-size:13px;min-width:220px}
.search .kbd{margin-left:auto}
.av{width:32px;height:32px;border-radius:50%;display:grid;place-items:center;background:linear-gradient(135deg,var(--acc),#ff9f6b);color:#fff;font-weight:800;font-size:13px}

/* ===== 2. Chọn phần ===== */
.home{max-width:1200px;margin:0 auto;padding:34px 24px 110px}
.hgrid{display:grid;grid-template-columns:1.25fr 1fr;gap:24px;margin-bottom:24px}
.hello{padding:26px 30px;display:flex;flex-direction:column;justify-content:center}
.home h1{font:800 clamp(30px,3.8vw,46px)/1.15 "Be Vietnam Pro";margin:8px 0 0;letter-spacing:-.02em}
.home h1 em{color:var(--acc);font-style:normal}
.idc{padding:18px 24px}
.idc .r{display:flex;justify-content:space-between;gap:12px;padding:8px 0;border-bottom:1px dashed var(--line);font-size:14px}
.idc .r:last-child{border:0}.idc .r span{color:var(--mute)}.idc .r b{font-weight:600;text-align:right}
.picks{display:grid;grid-template-columns:1fr 1fr;gap:24px}
.pick{text-align:left;font:inherit;color:inherit;cursor:pointer;padding:10px;display:grid;grid-template-columns:47% 1fr;gap:4px;border-radius:26px;transition:transform .35s cubic-bezier(.2,.8,.2,1),box-shadow .35s}
.pick:hover{transform:translateY(-6px);box-shadow:0 40px 80px -34px rgba(30,45,80,.5)}
.scr{position:relative;min-height:240px;overflow:hidden;border-radius:18px}
.pk-zoom .scr{background:linear-gradient(140deg,#1f3a8a 0%,#3b5bdb 55%,#7f9cff 100%)}
.pk-bai .scr{background:linear-gradient(140deg,#b8361a 0%,#e8572a 55%,#ffb37a 100%)}
.scr::before{content:"";position:absolute;inset:0;background-image:radial-gradient(rgba(255,255,255,.22) 1px,transparent 1.2px);background-size:16px 16px;mask-image:linear-gradient(180deg,#000,transparent 90%)}
.scr .sheen{position:absolute;top:0;bottom:0;width:45%;left:-70%;background:linear-gradient(100deg,transparent,rgba(255,255,255,.4),transparent);transform:skewX(-18deg);transition:left .8s}
.pick:hover .sheen{left:140%}
.scr .big{position:absolute;right:10px;bottom:-24px;font:800 120px/1 "Be Vietnam Pro";color:rgba(255,255,255,.14)}
.scr .lab{position:absolute;left:12px;top:12px;display:flex;gap:7px;align-items:center;font:700 10px var(--mono);letter-spacing:.06em;color:#fff;background:rgba(0,0,0,.25);border:1px solid rgba(255,255,255,.25);padding:5px 9px;border-radius:999px}
.scr .lab b{width:7px;height:7px;border-radius:50%;background:#ff5a5a;animation:pulse 1.8s infinite}
@keyframes pulse{0%{box-shadow:0 0 0 0 rgba(255,90,90,.7)}70%{box-shadow:0 0 0 8px rgba(255,90,90,0)}}
.mock{position:absolute;left:50%;top:57%;width:84%;transform:translate(-50%,-50%) perspective(900px) rotateX(10deg);background:rgba(255,255,255,.96);border-radius:12px;box-shadow:0 26px 44px -16px rgba(0,0,0,.45);overflow:hidden;transition:transform .5s cubic-bezier(.2,.8,.2,1)}
.pick:hover .mock{transform:translate(-50%,-54%) perspective(900px) rotateX(0) scale(1.04)}
.mock .bar{display:flex;gap:4px;padding:6px 8px;background:#f1f3f8}.mock .bar i{width:6px;height:6px;border-radius:50%;background:#d3d9e3}
.mz{display:grid;grid-template-columns:1.5fr 1fr;gap:6px;padding:8px}
.mz .v{aspect-ratio:16/10;border-radius:7px;background:linear-gradient(135deg,#1f3a8a,#5b7cfa);display:grid;place-items:center;position:relative}
.mz .v::after{content:"";border-left:11px solid #fff;border-top:7px solid transparent;border-bottom:7px solid transparent;margin-left:3px}
.mz .v span{position:absolute;left:5px;bottom:5px;font:700 8px var(--mono);color:#fff;background:rgba(0,0,0,.35);padding:1px 4px;border-radius:3px}
.mz .s{display:grid;gap:5px;align-content:start}
.mz .s div{border-radius:6px;background:#eef1f6;padding:5px 6px;font:700 8.5px/1.25 "Be Vietnam Pro";color:#46506a}
.mz .s div.on{background:#e7ecff;color:#2a45c4;box-shadow:inset 2px 0 0 #3b5bdb}
.mb{padding:8px 9px 10px;display:grid;gap:6px}
.mb .c{display:flex;align-items:center;gap:7px;font:700 8.5px "Be Vietnam Pro";color:#46506a}
.mb .c em{flex:none;width:17px;height:17px;border-radius:5px;display:grid;place-items:center;font:800 8px "Be Vietnam Pro";font-style:normal;background:#fbece5;color:#b8361a}
.mb .c span{flex:1;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.mb .c u{flex:none;width:44px;height:4px;border-radius:3px;background:#edf0f5;position:relative;overflow:hidden}
.mb .c u::after{content:"";position:absolute;left:0;top:0;bottom:0;width:var(--w);background:linear-gradient(90deg,#e8572a,#ffb37a)}
.tx{padding:14px 14px 10px 18px;display:flex;flex-direction:column}
.kk{display:flex;justify-content:space-between;align-items:center;gap:8px;font-size:12px;font-weight:700;letter-spacing:.14em;text-transform:uppercase;color:var(--mute)}
.chipx{letter-spacing:0;text-transform:none;font-size:11.5px;font-weight:700;padding:4px 9px;border-radius:999px;white-space:nowrap}
.pk-zoom .chipx{background:#e7ecff;color:#2a45c4}.pk-bai .chipx{background:#fdeae2;color:#b8361a}
.pick h2{font:800 clamp(21px,2vw,26px)/1.25 "Be Vietnam Pro";margin:12px 0 0;letter-spacing:-.01em}
.ft{margin-top:auto;padding-top:14px}
.ft .pg{font-size:13px;color:var(--mute);margin-bottom:12px}
.ft .pg u{display:block;height:6px;border-radius:4px;background:#e9edf3;margin-top:6px;overflow:hidden;text-decoration:none}
.ft .pg u i{display:block;height:100%;border-radius:4px}
.pk-zoom .ft .pg u i{background:linear-gradient(90deg,#3b5bdb,#7f9cff)}.pk-bai .ft .pg u i{background:linear-gradient(90deg,#e8572a,#ffb37a)}
.cta{display:flex;justify-content:space-between;gap:10px;align-items:center;padding:11px 12px 11px 18px;border-radius:999px;color:#fff;font-weight:700;font-size:14px;transition:.25s}
.pk-zoom .cta{background:#3b5bdb;box-shadow:0 10px 22px -8px rgba(59,91,219,.7)}.pk-bai .cta{background:#e8572a;box-shadow:0 10px 22px -8px rgba(232,87,42,.7)}
.cta b{width:26px;height:26px;border-radius:50%;background:rgba(255,255,255,.25);display:grid;place-items:center;transition:.25s}
.pick:hover .cta b{transform:translateX(4px);background:#fff;color:var(--ink)}

/* ===== 3. Trang học: đúng khung 3 cột của mẫu 3 (300 | video | 320), bản sáng ===== */
.learn{display:grid;grid-template-columns:300px minmax(0,1fr) 320px;min-height:calc(100vh - 60px)}
.cur-list{border-right:1px solid var(--line);padding:14px 10px 100px;overflow:auto;max-height:calc(100vh - 60px);position:sticky;top:60px;background:rgba(244,246,250,.9);backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px)}
.pgx{padding:4px 4px 14px}
.pgx .r{display:flex;justify-content:space-between;font-size:13px;color:var(--mute);font-weight:600}.pgx .r b{color:var(--ink);font-family:var(--mono)}
.seg{display:flex;gap:2px;margin-top:10px}.seg i{flex:1;height:6px;border-radius:2px;background:#dfe5ed}.seg i.on{background:var(--ink)}
.chap{background:#fff;border:1px solid var(--line);border-radius:14px;margin-bottom:9px;overflow:hidden;transition:box-shadow .2s}
.chap.open{box-shadow:0 12px 28px -18px rgba(30,45,80,.45)}
.ch-h{display:flex;gap:11px;align-items:center;width:100%;padding:12px;background:none;border:0;text-align:left;font:inherit;color:inherit;cursor:pointer}
.ch-h:hover{background:#f8f9fb}
.ch-no{flex:none;width:40px;height:40px;border-radius:11px;display:grid;place-items:center;font-weight:800;font-size:15px;background:#eef1f5;color:var(--ink);transition:.2s}
.chap.open .ch-no{background:var(--ink);color:#fff}
.ch-t{flex:1;min-width:0}
.ch-t small{display:block;font:700 10.5px var(--mono);letter-spacing:.1em;color:var(--dim)}
.ch-t b{display:block;font-size:14px;line-height:1.35;font-weight:700;margin:1px 0 6px}
.ch-p{display:flex;align-items:center;gap:8px;font:600 11.5px var(--mono);color:var(--mute)}
.ch-p u{flex:1;height:4px;border-radius:3px;background:#edf0f4;overflow:hidden;text-decoration:none}
.ch-p u i{display:block;height:100%;background:var(--ink);border-radius:3px}
.car{flex:none;color:var(--dim);transition:transform .25s}
.chap.open .car{transform:rotate(180deg)}
.ch-b{display:none;border-top:1px solid var(--line)}
.chap.open .ch-b{display:block}
.ls{display:flex;gap:11px;align-items:flex-start;padding:11px 12px;cursor:pointer;border-top:1px solid #f1f3f7;position:relative}
.ls:first-child{border-top:0}
.ls:hover{background:#f8f9fb}
.ls .n{flex:none;width:24px;height:24px;border-radius:50%;display:grid;place-items:center;font:700 11px var(--mono);border:1.5px solid #d3dae4;color:var(--mute);background:#fff;margin-top:1px}
.ls.done .n{background:var(--ink);border-color:var(--ink);color:#fff}
.ls .w{flex:1;min-width:0}
.ls .w span{display:block;font-size:14px;line-height:1.45;color:#2a3342}
.ls .w small{display:flex;gap:8px;align-items:center;margin-top:3px;font:500 11.5px var(--mono);color:var(--dim)}
.ls .w small em{font:600 11px "Be Vietnam Pro";font-style:normal;color:var(--mute);border:1px solid var(--line);border-radius:6px;padding:0 6px}
.ls.done .w span{color:var(--mute)}
.ls.cur{background:#fff5f0}
.ls.cur::before{content:"";position:absolute;left:0;top:8px;bottom:8px;width:3px;border-radius:0 3px 3px 0;background:var(--acc)}
.ls.cur .n{background:var(--acc);border-color:var(--acc);color:#fff}
.ls.cur .w span{color:var(--ink);font-weight:700}
.ls.cur .w small::after{content:"Đang xem";font:700 11px "Be Vietnam Pro";color:var(--acc)}
.mid{padding:24px clamp(16px,2.5vw,36px) 100px;min-width:0}
.player{position:relative;aspect-ratio:16/9;border-radius:14px;overflow:hidden;border:1px solid var(--line);background:#151b27;box-shadow:0 30px 70px -34px rgba(20,30,55,.6)}
.player .grid{position:absolute;inset:0;background-image:linear-gradient(#ffffff0a 1px,transparent 1px),linear-gradient(90deg,#ffffff0a 1px,transparent 1px);background-size:40px 40px}
.player .glow{position:absolute;inset:0;background:radial-gradient(50% 60% at 50% 50%,rgba(255,255,255,.1),transparent 70%)}
.player .play{position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);width:72px;height:72px;border-radius:18px;border:0;background:#fff;display:grid;place-items:center;cursor:pointer;box-shadow:0 0 50px rgba(255,255,255,.4);transition:.2s}
.player .play:hover{transform:translate(-50%,-50%) scale(1.06)}
.player .tl{position:absolute;left:18px;right:18px;bottom:16px;display:flex;align-items:center;gap:12px;font:500 12px var(--mono);color:rgba(255,255,255,.6)}
.player .tl i{flex:1;height:4px;border-radius:2px;background:#ffffff26}
.wm{position:absolute;right:16px;top:14px;font:700 12px var(--mono);color:#ffffff40;letter-spacing:.2em}
.lsbox{margin-top:18px;padding:18px 22px;background:#fff;border:1px solid var(--line);border-radius:16px;box-shadow:0 18px 40px -28px rgba(30,45,80,.4)}
.lsbox .k{font:700 12px var(--mono);color:var(--acc)}
.lsbox h1{margin:6px 0 16px;font-size:clamp(21px,2.2vw,28px);line-height:1.25;letter-spacing:-.02em}
.navb{display:flex;gap:10px;flex-wrap:wrap}
.navb .btn{border-radius:10px;padding:11px 18px;font-size:14px}
.res{border-left:1px solid var(--line);padding:24px 18px 100px;background:rgba(244,246,250,.9);backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px)}
.res h3{margin:0 0 4px;font-size:15px}.res .s{color:var(--dim);font-size:13px;margin:0 0 16px}
.pbox{padding:14px;margin-bottom:12px;font-size:13.5px;background:#fff;border:1px solid var(--line);border-radius:14px}
.pbox .h{display:flex;justify-content:space-between;align-items:center;margin-bottom:8px;font:700 11px var(--mono);color:var(--dim)}
.pbox .h button{background:#fff;border:1px solid var(--line);color:var(--ink);border-radius:7px;padding:4px 9px;font:700 11px var(--mono);cursor:pointer}
.pbox .h button:hover{border-color:var(--acc);color:var(--acc)}
.fl{display:flex;gap:12px;align-items:center;padding:12px 14px;margin-bottom:10px;cursor:pointer;background:#fff;border:1px solid var(--line);border-radius:14px}
.fl .ic{width:36px;height:36px;border-radius:9px;display:grid;place-items:center;background:#fdeae2;color:var(--acc);font:800 10px var(--mono)}
.fl small{display:block;color:var(--dim);font-size:12px}
.empty{border:1px dashed #c8d0db;border-radius:12px;padding:18px;color:var(--mute);font-size:13px;text-align:center;background:#fff}
.sup{margin-top:18px;padding:14px;font-size:13px;color:var(--mute);background:#fff;border:1px solid var(--line);border-radius:14px}.sup b{color:var(--ink)}
@media(min-width:1201px){.home{max-width:1280px}.scr{min-height:310px}.pick h2{font-size:30px;margin-top:16px}.tx{padding:20px 20px 14px 24px}.ft .pg{font-size:14px}.cta{padding:13px 14px 13px 20px;font-size:15px}.mock{width:80%}.mz .s div,.mb .c{font-size:10px}}
@media(max-width:1200px){.learn{grid-template-columns:300px minmax(0,1fr)}.res{grid-column:2;border:0;padding-top:0;background:none;backdrop-filter:none}
  .picks{grid-template-columns:1fr}}
@media(max-width:980px){.login,.hgrid{grid-template-columns:1fr}.stage{height:500px;min-height:0}}
@media(max-width:860px){.learn{grid-template-columns:1fr}.cur-list{position:static;max-height:none;border:0;order:3}.res{grid-column:auto}.search,.crumbs,.sep{display:none}}
@media(max-width:620px){.pick{grid-template-columns:1fr}.scr{min-height:190px}.lgf{padding:24px}.hello{padding:20px 22px}
  .stage{height:460px}.plat{font-size:13px;padding:8px 12px 8px 8px}.plat i{width:24px;height:24px}.p1{left:2%;bottom:104px}.p2{left:22%;bottom:186px}.p3{left:3%;bottom:268px}}

/* ===== phần riêng của trang thật (video Vimeo, đăng nhập, tài liệu) ===== */
.loading{position:fixed;inset:0;z-index:2;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:14px;color:var(--mute);font-weight:600}
.spin{width:38px;height:38px;border-radius:50%;border:3px solid #d3dae5;border-top-color:var(--acc);animation:sp .8s linear infinite}
@keyframes sp{to{transform:rotate(360deg)}}
.btn:disabled{opacity:.6;cursor:default;transform:none}
.lg-err{margin:12px 0 0;background:#fdecea;border:1px solid #f5b5ad;color:#b42318;font-size:14.5px;padding:10px 14px;border-radius:12px}
.lg-demo{margin:12px 0 0;font-size:13.5px;color:var(--acc)}
.small a{color:var(--acc2);font-weight:700;text-decoration:none}
.me{display:flex;align-items:center;gap:10px;font-size:14px;font-weight:600}
.me-out{background:#fff;border:1px solid var(--line);border-radius:9px;padding:6px 12px;font:600 13px "Be Vietnam Pro";cursor:pointer;color:var(--mute)}
.me-out:hover{border-color:var(--ink);color:var(--ink)}
.lg .t{white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:46vw}
/* chọn phần */
.pick:disabled{cursor:default;opacity:.62}
.pick:disabled:hover{transform:none;box-shadow:0 1px 0 #fff inset,0 24px 60px -26px rgba(30,45,80,.32)}
.pick .cta.off{background:#9aa3b2!important;box-shadow:none!important}
.pick .chipx.off{background:#eef0f4!important;color:var(--mute)!important}
.mz .s div{white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.mz .s .more{background:none!important;color:var(--dim)!important;padding:0 6px!important}
/* khung video */
.player{aspect-ratio:auto;background:#000}
.ratio{position:relative;padding-top:56.25%;background:#000}
.ratio iframe{position:absolute;inset:0;width:100%;height:100%;border:0}
.soon{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:8px;text-align:center;padding:20px;color:#fff;
  background:radial-gradient(50% 60% at 50% 50%,rgba(255,255,255,.1),transparent 70%),#151b27}
.soon b{font-size:clamp(18px,3vw,24px)}.soon span{color:rgba(255,255,255,.7);font-size:15px}.soon i{font-style:normal;font-size:40px}
.wm{position:absolute;z-index:5;pointer-events:none;user-select:none;font:700 clamp(11px,1.6vw,15px) var(--mono);color:rgba(255,255,255,.32);text-shadow:0 1px 2px rgba(0,0,0,.5);
  letter-spacing:.2em;top:8%;left:6%;transition:top 1.5s,left 1.5s;right:auto}
.fs{position:absolute;z-index:6;top:10px;right:10px;width:38px;height:38px;border-radius:10px;border:0;cursor:pointer;color:#fff;background:rgba(0,0,0,.55);display:grid;place-items:center;opacity:.85}
.fs:hover{opacity:1}
.player:fullscreen,.player.pseudo-fs{border-radius:0;border:0;box-shadow:none;display:flex;align-items:center;justify-content:center;background:#000}
.player.pseudo-fs{position:fixed;inset:0;z-index:100}
.player:fullscreen .ratio,.player.pseudo-fs .ratio{width:min(100vw,177.78vh);padding-top:0;height:min(56.25vw,100vh)}
.player:-webkit-full-screen .ratio{width:min(100vw,177.78vh);padding-top:0;height:min(56.25vw,100vh)}
/* dưới video */
.lsbox .desc{color:var(--mute);margin:-8px 0 14px;font-size:15px}
.lsbox .desc:empty{display:none}
.ls-exp{background:#fff6e5;border:1px solid #f4d38b;color:#8a5a00;padding:10px 14px;border-radius:12px;font-size:14px;margin:0 0 14px}
.ls-doc:empty{display:none}
.ls-doc a{display:inline-flex;align-items:center;gap:8px;margin:0 0 14px;color:var(--acc);font-weight:700;text-decoration:none;border:1px dashed var(--acc);border-radius:10px;padding:8px 12px;font-size:14px}
/* danh sách bài: nhãn phụ */
.ls .w small em.soon-t{color:var(--dim)}
.ls.soon-ls .w span{color:var(--dim)}
.chap.ch-zoom .ch-no{font-size:14px}
/* cột tài liệu */
.pbox .h b{font:700 13px "Be Vietnam Pro";color:var(--ink);letter-spacing:0}
.pbox .h button.ok{border-color:var(--ok);color:var(--ok)}
.pbox pre{white-space:pre-wrap;word-break:break-word;font:500 13px/1.55 "Be Vietnam Pro";margin:0;color:#2a3342;max-height:220px;overflow:auto}
.pbox .hint{margin:8px 0 0;font-size:12.5px;color:var(--mute)}
.res-sub{font:700 11px var(--mono);letter-spacing:.06em;color:var(--dim);margin:16px 0 8px;text-transform:uppercase}
.fl{text-decoration:none;color:var(--ink)}
.fl .fl-t{flex:1;min-width:0}.fl .fl-t b{display:block;font-size:13.5px}.fl .fl-t span{display:block;color:var(--dim);font-size:12px;line-height:1.4}
.fl .fl-btn{flex:none;font:700 12px "Be Vietnam Pro";color:var(--acc)}
.fl:hover{border-color:var(--acc)}
.res-note{font-size:12.5px;color:var(--mute);margin:10px 0 0}
.sup a{color:var(--acc2);font-weight:700;text-decoration:none}
.bar2{height:6px;border-radius:4px;background:#dfe5ed;margin-top:10px;overflow:hidden}.bar2 i{display:block;height:100%;width:0;background:var(--ink);border-radius:4px;transition:width .4s}
/* nút bài trong danh sách: bỏ kiểu nút mặc định của trình duyệt */
button.ls{width:100%;background:#fff;border:0;border-top:1px solid #f1f3f7;text-align:left;font:inherit;color:inherit;margin:0}
button.ls:first-child{border-top:0}
button.ls:hover{background:#f8f9fb}
button.ls.cur{background:#fff5f0}
@media(max-width:620px){#meName{display:none}.lg .t{max-width:58vw}.top{gap:10px;padding:0 14px}}
.back{white-space:nowrap}@media(max-width:620px){.back{padding:6px 10px}.top:has(.back:not([hidden])) .lg .t{display:none}.navb .btn{flex:1 1 auto}.learn{min-width:0}.mid{padding:16px 14px 40px}.res{padding:10px 14px 40px}}
@media(max-width:620px){.login{min-height:0;padding:10px 16px 28px;gap:4px;align-items:start}.stage{height:350px}.p1{bottom:58px}.p2{bottom:130px}.p3{bottom:202px}}
.glass,.top,.cur-list,.res{backdrop-filter:none!important;-webkit-backdrop-filter:none!important}
.glass{background:#fff}.top{background:rgba(255,255,255,.96)}.cur-list,.res{background:rgba(244,246,250,.97)}
#bot3d{width:auto;height:auto}
.shadow{width:96px;height:18px;margin:0 0 -8px -48px;background:radial-gradient(closest-side,rgba(24,34,58,.62),rgba(24,34,58,.26) 55%,transparent)}
@media(max-width:620px){.shadow{width:72px;height:14px;margin:0 0 -6px -36px}}
.shadow{position:absolute;left:0;bottom:0;border-radius:50%;z-index:2;pointer-events:none;will-change:transform}
body{background:radial-gradient(75% 70% at 50% 46%,#eef1f6 0%,#dde3ec 48%,#c5cedb 100%) fixed}

/* Bé Pu ảnh */
#pu{position:absolute;right:-3%;bottom:22px;height:min(430px,88%);aspect-ratio:620/960;z-index:1;pointer-events:none;transform-origin:50% 100%;transform:rotate(var(--lean,0deg));transition:transform .5s ease-out}
#pu img{position:absolute;inset:0;width:100%;height:100%;opacity:0;transform-origin:50% 100%;animation:pubr 3.6s ease-in-out infinite}
#pu img.on{opacity:1}#pu img.fr{z-index:1;transition:opacity .18s}#pu img.now{z-index:2}#pu img.mir{scale:-1 1}
#pu.hop{animation:puhop .42s cubic-bezier(.3,1.5,.5,1)}
#pu.wave img.on{animation:puwave .7s ease-in-out infinite}
@keyframes pubr{0%,100%{transform:scale(1,1)}50%{transform:scale(1.004,1.01)}}
@keyframes puhop{0%{translate:0 0}40%{translate:0 -12px}100%{translate:0 0}}
@keyframes puwave{0%,100%{transform:rotate(-.8deg)}50%{transform:rotate(1deg)}}
.plat{z-index:2;transition:transform .3s cubic-bezier(.3,1.5,.5,1),border-color .25s,box-shadow .25s}
.plat.lit{transform:scale(1.06);border-color:var(--acc);box-shadow:0 2px 0 #f4c6b6,0 18px 30px -16px rgba(232,87,42,.5)}
.bubble{z-index:4}
@media(max-width:980px){#pu{right:2%;height:88%}}
@media(max-width:620px){#pu{right:-9%;height:78%;bottom:20px}}
/* Bé Pu video: khung video lớn hơn #pu để người khớp đúng ảnh tư thế */
#pu video{position:absolute;left:1.9%;bottom:-5.9%;height:110.2%;width:96%;object-fit:contain;opacity:0;z-index:2}#pu video.on{opacity:1}#pu video.mir{scale:-1 1;z-index:3;transition:opacity .25s}