:root{
  --navy:#0f2b4c;--navy2:#1d4373;--gold:#c9a14f;--gold-d:#8f6f2e;--gold2:#e9d6a6;
  --paper:#f4f6fa;--card:#fff;--ink:#0d1b2e;--muted:#667085;--line:#e2e7ef;--soft:#f7f9fc;
  --ok:#2e7d57;--okbg:#e4f3ea;--bad:#c0392b;--badbg:#fceceb;--info:#e8eef8;
  --serif:'Inter','Segoe UI',system-ui,sans-serif;
  --sans:'Inter','Segoe UI',system-ui,sans-serif;
  --r:12px;--side:248px;
}
*{box-sizing:border-box}
html,body{margin:0}
body{background:var(--paper);color:var(--ink);font:15px/1.6 var(--sans);min-height:100vh;-webkit-font-smoothing:antialiased}
a{color:var(--navy2)}
h1,h2,h3,h4{font-family:var(--sans);color:var(--ink);line-height:1.25;margin:0 0 .45em;letter-spacing:-.01em}
h1{font-size:26px;font-weight:700}h2{font-size:21px;font-weight:700}h3{font-size:16px;font-weight:700}
.muted{color:var(--muted)}.small{font-size:13px}
.ic{width:18px;height:18px;stroke:currentColor;fill:none;stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round;vertical-align:-3px;flex:none}
.ic.sm{width:15px;height:15px;vertical-align:-2px}

/* ===== Khung: sidebar + nội dung ===== */
.shell{display:grid;grid-template-columns:var(--side) 1fr;min-height:100vh}
.side{background:linear-gradient(180deg,#fff 0,#fbfcf8 100%);color:#475467;border-right:1px solid var(--line);padding:20px 14px 16px;display:flex;flex-direction:column;gap:4px;position:sticky;top:0;height:100vh;overflow-y:auto}
.brand{display:flex;align-items:center;gap:11px;text-decoration:none;color:var(--navy);padding:2px 8px 20px}
.brand b{display:block;font:700 16px/1.2 var(--sans)}
.brand small{display:block;color:var(--muted);font-size:12px;margin-top:2px}
.crest{width:34px;height:34px;border-radius:9px;background:var(--navy);color:var(--gold);display:grid;place-items:center;font:800 18px var(--sans);flex:none}
#nav{display:flex;flex-direction:column;gap:2px}
#nav a{color:#475467;text-decoration:none;padding:10px 12px;border-radius:10px;font-size:15px;font-weight:600;display:flex;gap:14px;align-items:center}
#nav a .ic{width:22px;height:22px;stroke-width:1.6}
#nav a:hover{background:#f2f5fa;color:var(--navy)}
#nav a.on{background:#e8eef8;color:var(--navy)}
.nav-label{display:flex;align-items:center;gap:10px;margin:14px 0 4px;padding:0 12px;font:700 12px var(--sans);letter-spacing:.08em;text-transform:uppercase;color:#475467}
.nav-label:after{content:"";flex:1;height:1px;background:var(--line)}
.side-ha{margin-top:auto;background:#f3f6fb;border:1px solid var(--line);border-radius:14px;padding:0 14px 14px;overflow:hidden;text-align:center}
.side-ha-img{height:150px;display:flex;align-items:flex-end;justify-content:center;margin:0 -14px;background:linear-gradient(180deg,rgba(201,161,79,.20),rgba(201,161,79,0))}
.side-ha-img img,.side-ha-img svg{height:140px;width:auto;max-width:100%;object-fit:contain;object-position:50% 100%;filter:none;animation:none}
.side-ha b{display:block;color:var(--navy);font-size:15px;margin-top:10px}
.side-ha span{display:block;color:var(--muted);font-size:12.5px;margin:2px 0 12px}
.side-ha .btn{width:100%;background:var(--navy);border-color:var(--navy);color:#fff}
.side-ha .btn:hover{background:var(--navy2);border-color:var(--navy2)}
.content{min-width:0;display:flex;flex-direction:column}
.top{position:sticky;top:0;z-index:20;display:flex;align-items:center;gap:16px;background:linear-gradient(100deg,#e9f1fc 0%,#efeafb 45%,#fdeee6 100%);padding:11px 34px;border-bottom:1px solid #e3e6f3}
.crumb{font-weight:700;font-size:15px;color:var(--navy);white-space:nowrap}
.top-search{display:flex;align-items:center;gap:8px;background:rgba(255,255,255,.75);border:1px solid #dfe4f2;border-radius:999px;padding:0 14px;height:38px;width:270px;color:var(--muted);transition:background .12s,border-color .12s}
.top-search:focus-within{background:#fff;border-color:#9db4de;color:var(--navy2)}
.top-search input{flex:1;min-width:0;border:0!important;background:transparent;padding:0!important;font-size:14px;height:100%;border-radius:0!important}
.top-search input:focus{outline:none}
.top-chips{display:flex;gap:8px;flex-wrap:nowrap;min-width:0}
.top-chips .c3{display:none}
@media(min-width:1500px){.top-chips .c3{display:inline-flex}}
.um-btn{white-space:nowrap}
.tchip{display:inline-flex;align-items:center;gap:6px;border-radius:999px;padding:6px 13px;font-size:13px;font-weight:600;white-space:nowrap}
.tchip.c1{background:#e3defa;color:#4a3d9e}
.tchip.c2{background:#fde3cf;color:#9a4f12}
.tchip.c3{background:#d6f0e4;color:#1f6847}
.top-r{margin-left:auto;display:flex;align-items:center;gap:12px}
.menu-btn{display:none;background:#fff;border:1px solid var(--line);border-radius:9px;width:38px;height:38px;cursor:pointer;color:var(--navy)}
.side-scrim{display:none}
main{max-width:1080px;width:100%;margin:0 auto;padding:26px 34px 80px}

/* ===== Thành phần ===== */
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:20px}
.card.flat{box-shadow:none}
.card>h3:first-child{margin-bottom:14px}
.grid{display:grid;gap:16px}
.g2{grid-template-columns:1.6fr 1fr}.g3{grid-template-columns:repeat(3,1fr)}.g4{grid-template-columns:repeat(4,1fr)}
.chip{display:inline-flex;align-items:center;gap:6px;background:#fff;border:1px solid var(--line);color:var(--ink);padding:6px 12px;border-radius:9px;font-size:13px;font-weight:600}
.btn{font:600 14px var(--sans);border:1px solid #cdd5e1;background:#fff;color:var(--navy);padding:9px 16px;border-radius:9px;cursor:pointer;text-decoration:none;display:inline-block;transition:background .12s,border-color .12s}
.btn:hover{background:var(--soft);border-color:#b5c0d1}
.btn.gold{background:var(--gold);border-color:var(--gold);color:var(--navy)}.btn.gold:hover{background:#d3ac5c;border-color:#d3ac5c}
.btn.navy{background:var(--navy2);border-color:var(--navy2);color:#fff}.btn.navy:hover{background:var(--navy)}
.btn.ghost{border-color:var(--line);color:var(--muted);background:transparent}
.btn:disabled{opacity:.5;cursor:not-allowed}
.btn.sm{padding:5px 11px;font-size:13px}
.row{display:flex;gap:10px;align-items:center;flex-wrap:wrap}.spread{justify-content:space-between}
.mt{margin-top:16px}.mb{margin-bottom:16px}
.tile{display:block;text-decoration:none;color:inherit;border-radius:var(--r);padding:18px;border:1px solid var(--line);background:var(--card);transition:border-color .12s}
.tile:hover{border-color:var(--navy2)}
.tile .k{font:600 12px var(--sans);letter-spacing:.06em;text-transform:uppercase;color:var(--gold-d)}
.tile h3{margin:4px 0}
.bar{height:6px;background:#eaeef5;border-radius:99px;overflow:hidden}
.bar i{display:block;height:100%;background:var(--navy2);border-radius:99px}
.bar.bad i{background:var(--bad)}.bar.ok i{background:var(--ok)}
.pill{display:inline-block;padding:2px 9px;border-radius:6px;font-size:12px;font-weight:600;background:var(--info);color:var(--navy2)}
.pill.ok{background:var(--okbg);color:var(--ok)}.pill.bad{background:var(--badbg);color:var(--bad)}.pill.gold{background:#f6ecd3;color:var(--gold-d)}
.rem{border-left:3px solid var(--gold);background:#fbf8ef;padding:10px 14px;border-radius:0 9px 9px 0;margin-bottom:10px;font-size:14px}
.rem.bad{border-color:var(--bad);background:var(--badbg)}
.list .it{display:flex;gap:12px;align-items:center;padding:12px 4px;border-bottom:1px solid #eef1f6}
.list .it:last-child{border:0}
.list .it .t{flex:1}
.num{width:28px;height:28px;border-radius:8px;background:#eef1f6;color:var(--muted);display:grid;place-items:center;font:700 13px var(--sans);flex:none}
.num.done{background:var(--okbg);color:var(--ok)}.num.lock{background:#eef1f6;color:#b4bccb}
.tabs{display:flex;gap:4px;border-bottom:1px solid var(--line);margin-bottom:18px;flex-wrap:wrap}
.tabs button{background:none;border:0;padding:10px 16px;font:600 14px var(--sans);color:var(--muted);cursor:pointer;border-bottom:2px solid transparent;margin-bottom:-1px}
.tabs button.on{color:var(--navy);border-color:var(--navy2)}
.prose p{margin:.5em 0}.prose ul{margin:.4em 0;padding-left:20px}
.ex{border-left:3px solid var(--line);padding:4px 12px;margin:8px 0;background:var(--soft)}
.ex b{color:var(--navy)}
.trap{background:var(--badbg);border-radius:8px;padding:8px 12px;margin:6px 0;color:#7a2c1e}
table.t{width:100%;border-collapse:collapse}
table.t th,table.t td{text-align:left;padding:9px 10px;border-bottom:1px solid #eef1f6;vertical-align:top}
table.t th{font-size:12px;text-transform:uppercase;letter-spacing:.05em;color:var(--muted)}
.ipa{font-family:'Segoe UI',sans-serif;color:var(--navy2)}

/* ===== Trang chủ ===== */
.page-h{display:flex;align-items:flex-end;gap:14px;margin-bottom:20px;flex-wrap:wrap}
.page-h .sub{color:var(--muted);font-size:14px;margin-top:2px}
.page-h .r{margin-left:auto;display:flex;gap:10px}
.coach{position:relative;background:linear-gradient(110deg,#0f2b4c 0%,#16406e 100%);color:#fff;border-radius:16px;padding:28px 440px 28px 30px;min-height:240px;overflow:hidden;margin-bottom:18px}
.coach:before{content:"";position:absolute;right:0;top:0;bottom:0;width:380px;background:radial-gradient(circle at 62% 70%,rgba(233,214,166,.30),rgba(233,214,166,0) 62%)}
.coach .eyebrow{font:600 12px var(--sans);letter-spacing:.1em;text-transform:uppercase;color:var(--gold2);margin-bottom:8px}
.coach h2{color:#fff;font-size:22px;margin-bottom:6px}
.coach p{margin:0 0 18px;color:#c9d6ea;font-size:14.5px;max-width:520px}
.coach .btn{border-color:rgba(255,255,255,.35);background:transparent;color:#fff}
.coach .btn:hover{background:rgba(255,255,255,.1)}
.coach .btn.gold{background:var(--gold);border-color:var(--gold);color:var(--navy)}
.coach-ha{position:absolute;right:24px;bottom:0;width:270px;height:100%;display:flex;align-items:flex-end;justify-content:center;z-index:1}
.coach-ha img,.coach-ha svg{height:112%;width:auto;max-width:100%;object-fit:contain;object-position:50% 100%;filter:none;animation:none;margin-bottom:-6px}
.coach-say{position:absolute;right:236px;top:26px;z-index:2;width:190px;background:#fff;color:var(--ink);font-size:13px;line-height:1.45;padding:10px 13px;border-radius:12px 12px 2px 12px;box-shadow:0 6px 18px rgba(0,0,0,.18)}
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:14px;margin-bottom:18px}
.stat{background:#fff;border:1px solid var(--line);border-radius:12px;padding:16px}
.stat .k{font-size:12px;color:var(--muted);font-weight:500}
.stat .v{font:700 26px var(--sans);color:var(--ink);margin-top:2px;letter-spacing:-.02em}
.stat .v small{font-size:14px;color:var(--muted);font-weight:500;margin-left:2px}
.stat .d{font-size:12px;color:var(--muted);margin-top:2px}
.lesson-row{display:flex;gap:16px;align-items:center;background:var(--soft);border:1px solid var(--line);border-radius:11px;padding:16px;margin-bottom:6px}
.lesson-row .ic-box{width:44px;height:44px;border-radius:10px;background:var(--info);color:var(--navy2);display:grid;place-items:center;flex:none}
.lesson-row .ic-box .ic{width:22px;height:22px}
.lesson-row b{display:block;font-size:15px}.lesson-row span.m{font-size:13px;color:var(--muted)}
.lesson-row .btn{margin-left:auto;white-space:nowrap}
.weekrow{display:flex;gap:12px;align-items:center;padding:11px 2px;border-top:1px solid #eef1f6;font-size:14px;text-decoration:none;color:inherit}
.weekrow:first-of-type{border-top:0}
.weekrow:hover .wt{color:var(--navy2)}
.weekrow .wt{flex:1;min-width:0}.weekrow .wt small{display:block;color:var(--muted);font-size:12.5px}
.weekrow .wm{font-size:12.5px;color:var(--muted)}
.weak .w{margin:14px 0}
.weak .w div{display:flex;justify-content:space-between;font-size:13.5px;font-weight:500;gap:10px}
.weak .w .bar{margin-top:6px}

/* ===== Từ điển (kiểu Cambridge) ===== */
.dict{max-width:860px;margin:0 auto}
.dsearch{position:relative;display:flex;align-items:center;background:#fff;border:2px solid var(--navy);border-radius:999px;padding:4px 4px 4px 22px;margin-bottom:26px}
.dsearch input{border:0!important;border-radius:0!important;padding:10px 0!important;font-size:18px;background:transparent;flex:1;min-width:0}
.dsearch input:focus{outline:none}
.dclear{background:none;border:0;cursor:pointer;color:var(--muted);padding:6px 10px;display:grid;place-items:center}
.dgo{width:46px;height:46px;border-radius:50%;border:0;background:#f5b800;color:var(--navy);cursor:pointer;display:grid;place-items:center;flex:none}
.dgo:hover{background:#ffc61a}
.dgo .ic{width:22px;height:22px;stroke-width:2.2}
.dsug{position:absolute;left:0;right:0;top:calc(100% + 6px);background:#fff;border:1px solid var(--line);border-radius:14px;box-shadow:0 14px 34px rgba(13,27,46,.14);z-index:15;overflow:hidden}
.dsug[hidden]{display:none}
.dsug button{display:flex;justify-content:space-between;gap:14px;width:100%;text-align:left;background:none;border:0;border-bottom:1px solid #eef1f6;padding:11px 20px;font:15px var(--sans);color:var(--ink);cursor:pointer}
.dsug button:last-child{border:0}
.dsug button:hover{background:var(--soft)}
.dsug span{color:var(--muted);font-size:13.5px;text-align:right}
.dhead{display:flex;align-items:flex-start;gap:16px;border-bottom:1px solid var(--line);padding-bottom:12px}
.dword{flex:1;min-width:0}
.dword h1{font-size:44px;font-weight:600;color:#1b2a52;margin:0 0 4px;letter-spacing:-.02em;word-break:break-word}
.dmeta{display:flex;align-items:center;gap:12px;flex-wrap:wrap}
.dpos{font-weight:700;font-style:italic;color:#1b2a52}
.dpos small{font-weight:500;font-style:normal;color:var(--muted)}
.dsave{background:#f5b800;border:0;border-radius:999px;padding:8px 18px;font:700 13.5px var(--sans);color:var(--navy);cursor:pointer;white-space:nowrap}
.dsave:hover{background:#ffc61a}
.dsave.on{background:#fff;border:1.5px solid #f5b800}
.dvi{color:#0a7bd6;font-size:17px;margin:6px 0}
.dvi.big{font-size:24px;margin:16px 0 4px}
.dsec{margin-top:26px}
.dband{background:#f5b800;color:var(--navy);font:600 13px var(--sans);letter-spacing:.06em;padding:8px 14px}
.dband.sub{background:#fff3cc}
.dloc{padding:14px 4px;border-bottom:1px solid var(--line)}
.dentry{padding:16px 4px 4px}
.dpos-l{font:700 17px var(--sans);font-style:italic;color:#1b2a52;margin-bottom:6px}
.ddefs{margin:0;padding-left:22px}
.ddefs>li{margin:0 0 14px;padding-left:4px}
.ddef{font-size:16.5px;font-weight:600;color:#1b2a52}
.dex{list-style:none;margin:6px 0 0;padding:0}
.dex li{position:relative;padding-left:16px;margin:5px 0;color:#2b3a67;font-size:15.5px}
.dex li:before{content:"•";position:absolute;left:2px}
.dex em,.dcorp em{font-style:italic;font-weight:700;color:#1b2a52;background:#fff3cc;padding:0 2px;border-radius:3px}
.dsrc{font-size:12.5px;color:var(--muted);border-top:1px solid var(--line);margin-top:10px;padding-top:8px}
.dcorp{padding:14px 4px;border-bottom:1px solid var(--line);font-size:16px;color:#1b2a52}
.dfrom{font:italic 12.5px var(--sans);color:var(--muted);margin-top:6px}
.dempty h4{font:700 12px var(--sans);letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin:22px 0 10px}
.dchips{display:flex;gap:8px;flex-wrap:wrap}
.dchip{background:#fff;border:1px solid var(--line);border-radius:999px;padding:6px 14px;text-decoration:none;color:var(--navy);font-weight:600;font-size:14px}
.dchip:hover{border-color:var(--navy2)}
.dsaved{display:grid;grid-template-columns:repeat(auto-fill,minmax(210px,1fr));gap:10px}
.dsaved-i{display:flex;flex-direction:column;background:#fff;border:1px solid var(--line);border-radius:10px;padding:10px 14px;text-decoration:none;color:var(--ink)}
.dsaved-i:hover{border-color:var(--navy2)}
.dsaved-i span{color:var(--muted);font-size:13px}
@media(max-width:700px){.dword h1{font-size:34px}.dhead{flex-wrap:wrap}}

/* ===== Làm bài (quiz) ===== */
.q-head{display:flex;justify-content:space-between;align-items:center;margin-bottom:12px;gap:10px;flex-wrap:wrap}
.timer{font:700 17px var(--sans);font-variant-numeric:tabular-nums;background:var(--navy);color:#fff;padding:3px 13px;border-radius:8px}
.timer.warn{background:var(--bad)}
.passage{background:var(--soft);border:1px solid var(--line);border-radius:10px;padding:14px 16px;margin-bottom:12px;white-space:pre-wrap}
.q-text{font-size:16.5px;margin:10px 0 14px;font-weight:500}
.opt{display:flex;gap:12px;width:100%;text-align:left;background:#fff;border:1.5px solid var(--line);border-radius:10px;padding:11px 14px;margin-bottom:9px;cursor:pointer;font:15px var(--sans);color:var(--ink)}
.opt:hover:not(:disabled){border-color:var(--navy2)}
.opt b{width:26px;height:26px;border-radius:7px;background:var(--info);display:grid;place-items:center;flex:none;font-size:13px;color:var(--navy)}
.opt.sel{border-color:var(--navy2);background:var(--info)}
.opt.ok{border-color:var(--ok);background:var(--okbg)}
.opt.no{border-color:var(--bad);background:var(--badbg)}
.explain{background:var(--info);border-radius:10px;padding:12px 14px;margin:10px 0}
.pal{display:flex;gap:6px;flex-wrap:wrap;margin:14px 0}
.pal button{width:34px;height:34px;border-radius:8px;border:1px solid var(--line);background:#fff;cursor:pointer;font-weight:600}
.pal button.ans{background:var(--info);border-color:var(--navy2)}.pal button.cur{outline:2px solid var(--navy2);outline-offset:1px}
.audio-btn{display:inline-flex;gap:8px;align-items:center}
textarea,input[type=text],select{font:15px var(--sans);border:1.5px solid var(--line);border-radius:9px;padding:10px 12px;width:100%;background:#fff;color:var(--ink)}
textarea:focus,input:focus,select:focus{outline:none;border-color:var(--navy2)}
.flash{max-width:520px;margin:0 auto}
.flash .face{min-height:270px;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;gap:8px;
  border-radius:16px;border:1px solid var(--line);background:#fff;padding:26px;cursor:pointer}
.flash .w{font:700 36px var(--sans);color:var(--navy);letter-spacing:-.02em}
.diff .ok{color:var(--ok)}.diff .no{color:var(--bad);text-decoration:line-through}.diff .miss{background:#fff1b8;padding:0 3px;border-radius:3px}

/* ===== Khung chat ===== */
.chat-fab{display:none;position:fixed;right:18px;bottom:18px;z-index:30;width:60px;height:60px;border-radius:50%;border:2px solid #fff;padding:0;overflow:hidden;background:#f3ead7;cursor:pointer;box-shadow:0 6px 20px rgba(15,43,76,.35)}
.chat-fab img,.chat-fab svg{width:100%;height:100%;object-fit:cover}
.chat-panel{position:fixed;right:22px;bottom:22px;z-index:31;width:390px;max-width:calc(100vw - 24px);height:560px;max-height:calc(100vh - 44px);
  background:#fff;border:1px solid var(--line);border-radius:16px;box-shadow:0 16px 48px rgba(13,27,46,.28);display:flex;flex-direction:column;overflow:hidden}
.chat-panel[hidden]{display:none}
.chat-head{background:var(--navy);color:#fff;padding:11px 14px;display:flex;align-items:center;gap:10px}
.chat-head b{font-size:15px}
.chat-head .head-ha{width:36px;height:36px;border-radius:50%;background:#f3ead7;overflow:hidden;flex:none;border:2px solid var(--gold)}
.msg-ha{display:flex;gap:8px;align-items:flex-end;align-self:flex-start;max-width:92%}
.msg-ha .av{width:30px;height:30px;border-radius:50%;background:#f3ead7;overflow:hidden;flex:none;border:1.5px solid var(--gold)}
.msg-ha .msg{max-width:none}
.chat-head .muted{color:#9fb0ca;font-size:12px;flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.chat-head .x{background:none;border:0;color:#fff;cursor:pointer;padding:4px;display:grid;place-items:center}
.chat-log{flex:1;overflow:auto;padding:14px;display:flex;flex-direction:column;gap:10px;background:var(--soft)}
.msg{max-width:88%;padding:9px 13px;border-radius:12px;white-space:pre-wrap;word-wrap:break-word}
.msg.u{align-self:flex-end;background:var(--navy2);color:#fff;border-bottom-right-radius:3px}
.msg.a{align-self:flex-start;background:#fff;border:1px solid var(--line);border-bottom-left-radius:3px}
.chat-form{display:flex;gap:8px;padding:10px;border-top:1px solid var(--line);background:#fff}
.chat-form textarea{resize:none}
.modal{position:fixed;inset:0;background:rgba(10,20,40,.55);z-index:50;display:grid;place-items:center;padding:16px}
.modal[hidden]{display:none}
.modal-box{background:#fff;border-radius:14px;padding:22px;max-width:680px;width:100%;max-height:90vh;overflow:auto}
.spin{display:inline-block;width:14px;height:14px;border:2px solid #cfd8e6;border-top-color:var(--navy2);border-radius:50%;animation:sp .8s linear infinite;vertical-align:-2px;margin-right:6px}
@keyframes sp{to{transform:rotate(360deg)}}
.ring{--p:0;width:92px;height:92px;border-radius:50%;background:conic-gradient(var(--navy2) calc(var(--p)*1%),#eaeef5 0);display:grid;place-items:center}
.ring span{width:70px;height:70px;border-radius:50%;background:#fff;display:grid;place-items:center;font:700 19px var(--sans);color:var(--navy)}
.ai-out{background:#fff;border:1px solid var(--line);border-radius:10px;padding:14px 16px;margin-top:10px;white-space:pre-wrap}

/* ===== Lý thuyết dạng thẻ ===== */
.theory{padding:24px}
.th-head{display:flex;gap:14px;align-items:center;margin-bottom:14px}
.th-i{width:44px;height:44px;border-radius:11px;background:var(--info);color:var(--navy2);display:grid;place-items:center;flex:none}
.th-i .ic{width:22px;height:22px}
.th-head h3{font-size:22px;margin:0}
.summary{background:var(--soft);border:1px solid var(--line);border-left:3px solid var(--gold);border-radius:10px;padding:14px 18px;margin:8px 0 16px}
.summary ul{margin:6px 0 0;padding-left:20px}.summary li{margin:3px 0;font-size:15px}
.legend{display:flex;gap:8px;flex-wrap:wrap;align-items:center;margin-bottom:14px}
.lg{font:600 12px var(--sans);color:#fff;background:var(--c);padding:3px 10px;border-radius:6px}
.blocks{display:grid;grid-template-columns:repeat(auto-fit,minmax(360px,1fr));gap:16px;align-items:start}
.tb{background:#fff;border:1px solid var(--line);border-radius:12px;padding:18px}
.tb-h{display:flex;align-items:center;gap:10px;margin-bottom:6px}
.tb-i{font:700 13px var(--sans);width:30px;height:30px;border-radius:8px;background:var(--navy);color:#fff;display:grid;place-items:center;flex:none}
.tb h4,h4{font:700 17px var(--sans);color:var(--ink);margin:0}
.tb-m{margin:6px 0 10px;font-size:15.5px}
.analogy{display:flex;gap:10px;background:#eef6f0;border-radius:10px;padding:10px 12px;margin:8px 0;font-size:14.5px}
.analogy>.ic,.tip>.ic,.trap2>.ic{margin-top:3px}
.formula-label{font:700 11px var(--sans);letter-spacing:.08em;text-transform:uppercase;color:var(--gold-d);margin:12px 0 6px}
.formula{display:flex;flex-wrap:wrap;gap:6px;align-items:center;background:var(--soft);border:1px dashed #cdd5e1;border-radius:10px;padding:12px}
.slot{background:color-mix(in srgb,var(--c) 10%,#fff);border:1.5px solid var(--c);color:var(--c);font-weight:700;padding:5px 12px;border-radius:8px}
.slot.target{background:var(--c);color:#fff}
.plus{color:var(--muted);font-weight:700}
.fnote{font-size:14px;color:var(--muted);margin-top:6px}
.signs{margin:10px 0}
.sign{display:inline-block;background:#f6efdc;border:1px solid #e6d7ae;color:#6e5316;font:600 13.5px monospace;padding:2px 9px;border-radius:6px;margin:2px 3px}
.ex2{border-left:3px solid var(--gold2);background:var(--soft);border-radius:0 10px 10px 0;padding:10px 14px;margin:10px 0}
.sent{display:flex;flex-wrap:wrap;gap:6px 8px;font-size:17px;line-height:2.1}
.seg{position:relative;display:inline-block;border-bottom:3px solid var(--c);color:var(--ink);padding:0 3px}
.seg em{position:absolute;top:-1.15em;left:0;font:600 10px var(--sans);color:var(--c);white-space:nowrap;font-style:normal}
.seg.hl{background:color-mix(in srgb,var(--c) 18%,#fff);font-weight:700;border-radius:4px}
.ex2.anim .seg{animation:pop .4s both;animation-delay:calc(var(--i)*.25s)}
.ex2 .vi{color:var(--muted);margin:2px 0 6px;font-size:14.5px}
.builder{margin-top:10px;background:#fff;border:1px solid var(--line);border-radius:10px;padding:12px}
.b-line{min-height:46px;display:flex;flex-wrap:wrap;gap:8px;align-items:center;border-bottom:2px dashed var(--line);padding-bottom:8px;margin-bottom:10px;font-size:16px}
.b-line.good{border-color:var(--ok);background:var(--okbg);border-radius:8px;padding:6px}
.b-line.bad{border-color:var(--bad);background:var(--badbg);border-radius:8px;padding:6px;animation:shake .4s}
.b-tray{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:10px}
.b-tray .chip,.chip.pick{font:600 15px var(--sans);background:#fff;border:1.5px solid var(--navy2);color:var(--navy);padding:6px 14px;border-radius:9px;cursor:pointer}
.b-tray .chip:hover{background:var(--navy2);color:#fff}
.b-msg{font-weight:600}
.cmp table{width:100%;border-collapse:separate;border-spacing:0;border:1px solid var(--line);border-radius:10px;overflow:hidden;font-size:14.5px}
.cmp th,.cmp td{padding:8px 10px;border-bottom:1px solid var(--line);text-align:left}
.cmp tr:last-child th,.cmp tr:last-child td{border-bottom:0}
.cmp tr:first-child th{background:var(--navy);color:#fff}
.cmp tr:first-child th.c1{background:#1f5fa8}.cmp tr:first-child th.c2{background:#c26a12}.cmp tr:first-child th.c0{background:#2e7d57}
.cmp td:nth-child(2){background:#eef4fb}.cmp td:nth-child(3){background:#fdf3e6}
.check{background:#f2f6fc;border:1px solid #d3deee;border-radius:10px;padding:12px;margin:12px 0}
.check .q{font-weight:600;margin:4px 0 8px}
.opt.sm{padding:7px 12px;margin-bottom:6px}
.tip,.trap2{display:flex;gap:10px;border-radius:10px;padding:10px 12px;margin:10px 0;font-size:14.5px}
.tip{background:#eaf3fb}.trap2{background:var(--badbg);color:#7a2c1e}
.flow{display:flex;flex-direction:column;align-items:stretch;max-width:640px}
.fstep{display:flex;gap:12px;align-items:center;background:#fff;border:1.5px solid var(--navy2);border-radius:11px;padding:10px 14px}
.fstep .n{width:28px;height:28px;border-radius:8px;background:var(--navy);color:#fff;display:grid;place-items:center;font-weight:700;flex:none}
.arrow{text-align:center;color:var(--gold-d);font-size:18px;line-height:1;margin:2px 0}
/* ===== Hình minh họa flashcard ===== */
.art{font-size:84px;line-height:1}
.art.sm{font-size:50px}
.face.flipin{animation:flipin .35s}
.em{font-size:22px;margin-right:4px}
@keyframes pop{0%{opacity:0;transform:scale(.8) translateY(6px)}100%{opacity:1;transform:none}}
@keyframes shake{0%,100%{transform:none}25%{transform:translateX(-6px)}75%{transform:translateX(6px)}}
@keyframes flipin{0%{transform:rotateY(90deg);opacity:.3}100%{transform:none;opacity:1}}
/* ===== Ảnh cô Hạ Anh ===== */
.ha-img{display:block;width:100%;height:auto}
.ha-img.mini,.fab-ha img,.head-ha img,.av img,.chat-fab .ha-img{width:100%;height:100%;object-fit:cover;scale:2.4;transform-origin:53% 31%}
.busy .ha-img{animation:talkbob .35s ease-in-out infinite alternate}
@keyframes talkbob{from{transform:scale(1)}to{transform:scale(1.04)}}
.chat-fab .ha-img{scale:2.4}
/* ===== Tài khoản ===== */
body.guest .side,body.guest .top,body.guest .side-scrim,body.guest #chatFab,body.guest #chatPanel{display:none!important}
body.guest .shell{display:block}
body.guest main{padding-top:48px}
input:not([type]),input[type=password],input[type=email]{display:block;box-sizing:border-box;font:15px var(--sans);border:1.5px solid var(--line);border-radius:9px;padding:10px 12px;width:100%;background:#fff;color:var(--ink)}
.auth{display:grid;grid-template-columns:1fr 1fr;gap:34px;align-items:center;max-width:920px;margin:10px auto}
.auth-art{text-align:center;background:linear-gradient(160deg,var(--navy),#16406e);border-radius:18px;padding:30px 24px 0;overflow:hidden;color:#fff}
.auth-art img,.auth-art svg{display:block;max-width:300px;width:100%;margin:0 auto}
.auth-art p{font:600 17px/1.4 var(--sans);color:#fff;margin:0;padding:18px 0 22px;order:2}
.aform label{display:block;font-size:14px;font-weight:600;margin-bottom:12px;color:var(--ink)}
.aform input{margin-top:5px;font-weight:400}
.aform .btn{width:100%;padding:12px}
@media(max-width:760px){.auth{grid-template-columns:1fr}.auth-art img,.auth-art svg{max-width:200px}}
.user-menu{position:relative}
.um-btn{display:flex;align-items:center;gap:8px;background:#fff;border:1px solid var(--line);color:var(--ink);padding:3px 12px 3px 3px;border-radius:999px;cursor:pointer;font:600 13.5px var(--sans)}
.uav{width:30px;height:30px;border-radius:50%;object-fit:cover;background:var(--navy);color:#fff;display:inline-grid;place-items:center;font-weight:700;font-size:13px}
.um-pop{position:absolute;right:0;top:46px;background:#fff;color:var(--ink);border:1px solid var(--line);border-radius:12px;box-shadow:0 14px 34px rgba(13,27,46,.2);padding:10px;min-width:190px;z-index:41;display:flex;flex-direction:column;gap:4px}
.um-pop[hidden]{display:none}
.um-pop a,.um-pop button{text-align:left;background:none;border:0;padding:8px;border-radius:8px;font:14px var(--sans);color:var(--ink);text-decoration:none;cursor:pointer}
.um-pop a:hover,.um-pop button:hover{background:var(--soft)}
.big-av .uav{width:84px;height:84px;font-size:34px}
.bgs{display:flex;gap:10px;flex-wrap:wrap}
.bgsw{width:58px;height:58px;border-radius:12px;border:2px solid var(--line);cursor:pointer;font-size:22px;color:var(--muted)}
.bgsw.on{border-color:var(--navy2);box-shadow:0 0 0 3px #d5e0f1}
.bgsw.up{background:#fff}
details.more{margin-top:10px;border-top:1px dashed var(--line);padding-top:8px}
details.more summary,details summary{cursor:pointer;color:var(--navy2);font-weight:600;font-size:14px}
/* ===== Chuông thông báo ===== */
.bell-wrap{position:relative}
.bell{position:relative;background:rgba(255,255,255,.85);border:1px solid #dfe4f2;width:38px;height:38px;border-radius:50%;cursor:pointer;color:var(--navy);display:grid;place-items:center}
.bell:hover{background:var(--soft)}
#bellN{position:absolute;top:-4px;right:-4px;background:var(--bad);color:#fff;font:700 11px var(--sans);min-width:18px;height:18px;border-radius:99px;display:grid;place-items:center;padding:0 4px;border:2px solid var(--paper)}
#bellN[hidden]{display:none}
.bell-panel{position:absolute;right:0;top:48px;width:360px;max-width:calc(100vw - 24px);background:#fff;color:var(--ink);border:1px solid var(--line);border-radius:14px;box-shadow:0 18px 44px rgba(13,27,46,.22);z-index:40;overflow:hidden}
.bell-panel[hidden]{display:none}
.bp-head{display:flex;justify-content:space-between;align-items:center;padding:12px 14px;border-bottom:1px solid var(--line)}
.bp-head .btn{margin-left:4px}
.bp-list{max-height:420px;overflow:auto}
.bp-item{display:flex;gap:11px;padding:11px 14px;border-bottom:1px solid #eef1f6;text-decoration:none;color:inherit}
.bp-item:hover{background:var(--soft)}
.bp-item.unread{background:#f3f7fd}
.bp-item.unread b:after{content:"";display:inline-block;width:7px;height:7px;border-radius:50%;background:var(--navy2);margin-left:6px;vertical-align:2px}
.bp-i,.toast .ti{width:32px;height:32px;border-radius:9px;background:var(--info);color:var(--navy2);display:grid;place-items:center;flex:none}
.bp-empty{padding:26px;text-align:center;color:var(--muted)}
.toasts{position:fixed;left:calc(var(--side) + 20px);bottom:20px;z-index:60;display:flex;flex-direction:column;gap:10px;max-width:340px}
.toast{display:flex;gap:11px;background:var(--navy);color:#fff;padding:12px 14px;border-radius:12px;box-shadow:0 12px 30px rgba(0,0,0,.3);cursor:pointer;animation:slidein .3s both}
.toast .ti{background:rgba(255,255,255,.14);color:#fff}
.toast .small{color:#c3d0e4}
.toast.out{opacity:0;transform:translateX(-20px);transition:.5s}
@keyframes slidein{from{opacity:0;transform:translateX(-20px)}to{opacity:1;transform:none}}

/* ===== Màn hình nhỏ ===== */
@media(max-width:980px){
  .shell{grid-template-columns:1fr}
  .side{position:fixed;left:0;top:0;bottom:0;width:var(--side);z-index:70;transform:translateX(-100%);transition:transform .2s}
  body.nav-open .side{transform:none}
  body.nav-open .side-scrim{display:block;position:fixed;inset:0;background:rgba(10,20,40,.5);z-index:65}
  .menu-btn{display:grid;place-items:center}
  .top{padding:10px 16px}
  .top-chips{display:none}
  .top-search{width:auto;flex:1;min-width:0}
  .crumb{display:none}
  main{padding:20px 16px 90px}
  .chat-fab{display:block}
  .toasts{left:16px}
  .stats{grid-template-columns:1fr 1fr}
  .g2,.g3,.g4{grid-template-columns:1fr 1fr}
}
@media(max-width:700px){
  .g2,.g3,.g4{grid-template-columns:1fr}
  .coach{padding:22px 20px 0;min-height:0}
  .coach-ha{position:relative;right:auto;width:100%;height:190px;margin-top:6px}
  .coach-say{position:relative;right:auto;top:auto;max-width:none;margin-bottom:14px;border-radius:12px}
  .coach:before{display:none}
  .lesson-row{flex-wrap:wrap}
  .blocks{grid-template-columns:1fr}
  .chat-panel{right:0;bottom:0;width:100vw;max-width:100vw;height:80vh;border-radius:16px 16px 0 0}
}
@media(prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}