:root{--bg:#F4F3EF;--paper:#FBFAF7;--ink:#131726;--dim:#545A70;--faint:#878DA0;--accent:#0B2A8F;--accent-ink:#F2F4FB;--line:rgba(19,23,38,.14);--soft:#E9EDFA;--bad:#B3261E;--good:#1B6E3C}
@media (prefers-color-scheme:dark){:root{--bg:#0A0E1A;--paper:#121830;--ink:#E8EBF5;--dim:#99A1B8;--faint:#6D7590;--accent:#8AA2FF;--accent-ink:#070B16;--line:rgba(232,235,245,.16);--soft:#1A2250;--bad:#FF8A80;--good:#7BD99B}}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font:400 16px/1.7 'Be Vietnam Pro',system-ui,sans-serif;-webkit-font-smoothing:antialiased}
body.center{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:24px 16px}
a{color:var(--accent)}
h1,h2,h3{font-family:'Cormorant Garamond',Georgia,serif;font-weight:600;line-height:1.2;margin:0 0 .5em}
h1{font-size:2.1rem}h2{font-size:1.5rem}h3{font-size:1.2rem}
.lead{color:var(--dim);margin:0 0 1.4em}
.fine{color:var(--faint);font-size:.88rem}
.card{background:var(--paper);border:1px solid var(--line);border-radius:14px;padding:32px 28px;width:100%;max-width:440px}
.card.wide{max-width:760px}
.card.login{text-align:center}
.brand{display:inline-flex;align-items:baseline;gap:8px;text-decoration:none;color:var(--ink);font-family:'Barlow Condensed',sans-serif;text-transform:uppercase;letter-spacing:.12em}
.brand b{font-weight:600;font-size:1.15rem}.brand span{font-size:.8rem;color:var(--dim)}
.brand.big{margin-bottom:22px}.brand.big b{font-size:1.6rem}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:10px;background:var(--accent);color:var(--accent-ink);border:0;border-radius:10px;padding:12px 22px;font:500 1rem 'Be Vietnam Pro',sans-serif;text-decoration:none;cursor:pointer;min-height:46px}
.btn:hover{filter:brightness(1.08)}
.btn.small{padding:7px 14px;min-height:36px;font-size:.9rem}
.btn.ghost{background:transparent;color:var(--accent);border:1px solid var(--accent)}
.btn.google{background:#fff;color:#1f1f1f;border:1px solid #dadce0;width:100%;margin:6px 0 18px}
.alert{background:#FCE8E6;color:#7A1710;border-radius:10px;padding:12px 14px;margin:0 0 16px;text-align:left;font-size:.95rem}
.alert.good{background:#E3F4E9;color:#14522B}
@media (prefers-color-scheme:dark){.alert{background:#3A1A18;color:#FFC9C4}.alert.good{background:#14301F;color:#B4F0C9}}
.bar{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:12px max(16px,4vw);background:var(--paper);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:5;flex-wrap:wrap}
.bar nav{display:flex;gap:4px;flex-wrap:wrap}
.bar nav a{padding:6px 12px;border-radius:8px;text-decoration:none;color:var(--dim);font-size:.95rem}
.bar nav a.on,.bar nav a:hover{background:var(--soft);color:var(--accent)}
.page{max-width:860px;margin:0 auto;padding:36px 20px 80px}
.page.wide{max-width:1040px}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:16px}
.tile{display:block;background:var(--paper);border:1px solid var(--line);border-radius:14px;padding:22px;text-decoration:none;color:var(--ink);transition:border-color .15s,transform .15s}
.tile:hover{border-color:var(--accent);transform:translateY(-2px)}
.tile p{color:var(--dim);font-size:.95rem;margin:.2em 0 1em}.tile .go{color:var(--accent);font-weight:500}
.check{display:flex;gap:10px;align-items:flex-start;margin:18px 0}
.check input{margin-top:6px;width:18px;height:18px}
.terms{max-height:46vh;overflow:auto;border:1px solid var(--line);border-radius:10px;padding:6px 18px;margin:0 0 8px;background:var(--bg);font-size:.95rem}
.terms h2{font-size:1.15rem;margin-top:1em}
.tools{display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:0 0 6px}
.tools input[type=search]{flex:1 1 220px;min-height:42px;border:1px solid var(--line);border-radius:10px;padding:8px 14px;background:var(--paper);color:var(--ink);font:inherit}
.course{margin:32px 0}
.sec{background:var(--paper);border:1px solid var(--line);border-radius:12px;padding:16px 20px;margin:0 0 14px}
.sec h3 a{text-decoration:none}
.note{border-top:1px dashed var(--line);padding:10px 0}
.note:first-of-type{border-top:0}
.note .meta{color:var(--faint);font-size:.82rem}
.note .body{margin-top:2px;overflow-wrap:anywhere}
.empty{text-align:center;padding:50px 0}
.panel{background:var(--paper);border:1px solid var(--line);border-radius:14px;padding:22px;margin:0 0 22px}
.panel textarea{width:100%;border:1px solid var(--line);border-radius:10px;padding:10px 12px;background:var(--bg);color:var(--ink);font:inherit;margin:0 0 12px}
.row{display:flex;gap:12px;align-items:center;flex-wrap:wrap}.row.between{justify-content:space-between}
.tablewrap{overflow-x:auto}
table{border-collapse:collapse;width:100%;font-size:.93rem}
th,td{text-align:left;padding:10px 10px;border-bottom:1px solid var(--line);vertical-align:top}
th{color:var(--dim);font-weight:500;font-size:.82rem;text-transform:uppercase;letter-spacing:.06em}
.acts form{display:flex;gap:2px 10px;flex-wrap:wrap}
button.link{background:none;border:0;color:var(--accent);cursor:pointer;font:inherit;padding:2px 0;text-decoration:underline}
button.link.danger,.bad{color:var(--bad)}.okc{color:var(--good)}
.tag{background:var(--soft);color:var(--accent);border-radius:6px;padding:1px 8px;font-size:.78rem}
@media print{.bar,.tools,.btn{display:none!important}body{background:#fff;color:#000}.sec{break-inside:avoid;border-color:#ccc}}

/* ---- Sổ tay của tôi (v3): giấy nhớ gom theo buổi ---- */
.tools select{min-height:42px;border:1px solid var(--line);border-radius:10px;padding:8px 12px;background:var(--paper);color:var(--ink);font:inherit}
.nbs h3{margin:0 0 4px}
.nb-grid{display:flex;flex-wrap:wrap;gap:26px 22px;padding:22px 4px 8px}
.nb-stk{--tilt:0deg;position:relative;flex:0 1 250px;width:250px;max-width:100%;box-sizing:border-box;background:var(--c);color:var(--ci);font:400 18px/1.38 'Patrick Hand','Segoe Print','Be Vietnam Pro',system-ui,sans-serif;padding:28px 16px 12px;border-radius:2px 2px 16px 2px/2px 2px 7px 2px;transform:rotate(var(--tilt));box-shadow:0 1px 1px rgba(19,23,38,.12),0 12px 18px -9px rgba(19,23,38,.36)}
.nb-stk::before{content:"";position:absolute;top:-10px;left:50%;width:70px;height:20px;transform:translateX(-50%) rotate(-2.5deg);background:rgba(255,255,255,.58);box-shadow:0 1px 1.5px rgba(19,23,38,.16)}
.nb-vang{--c:#F6E6A2;--ci:#33290A}.nb-hong{--c:#F6D3CC;--ci:#4A1B14}.nb-xanh{--c:#CDE7D5;--ci:#10392A}.nb-lam{--c:#CBDAF5;--ci:#0F2559}
.nb-k{display:inline-block;margin:0 0 8px;font:500 11px/1 'Be Vietnam Pro',system-ui,sans-serif;letter-spacing:.08em;text-transform:uppercase;opacity:.75}
.nb-q{margin:0 0 8px;padding:5px 9px;border-radius:6px;background:rgba(255,255,255,.46);font:400 13px/1.45 'Be Vietnam Pro',system-ui,sans-serif;font-style:italic;overflow-wrap:anywhere}
.nb-t{overflow-wrap:anywhere}
.nb-m{margin-top:10px;font:400 11.5px/1 'Be Vietnam Pro',system-ui,sans-serif;color:color-mix(in srgb,var(--ci) 72%,transparent)}
.print-head{display:none}
@media (max-width:640px){.nb-stk{flex:1 1 100%;width:auto}}
@media print{
  .print-head{display:block;margin:0 0 20px;padding-bottom:10px;border-bottom:1px solid #999}
  .ph-brand{font:500 13px/1 'Be Vietnam Pro',Arial,sans-serif;letter-spacing:.18em;text-transform:uppercase}.ph-brand span{color:#0B2A8F}
  .ph-title{margin-top:8px;font:500 26px/1.2 'Cormorant Garamond',Georgia,serif}.ph-date{margin-top:4px;font:400 12px/1 'Be Vietnam Pro',Arial,sans-serif;color:#555}
  main.page h1,main.page .lead,.fine,.bar{display:none!important}
  .nb-stk{break-inside:avoid;-webkit-print-color-adjust:exact;print-color-adjust:exact;box-shadow:none;transform:none}
  .nbs{border:0;padding:0}
}

/* v3.1: chọn khóa học cho học viên (admin) */
.crs-pick{margin:0 0 10px;display:flex;flex-wrap:wrap;gap:6px 18px;align-items:center}
.crs{display:inline-flex;align-items:center;gap:6px;font-size:14px;cursor:pointer;white-space:nowrap}
.crs input{width:16px;height:16px;accent-color:var(--accent,#0B2A8F)}
.crs-form{display:flex;flex-direction:column;align-items:flex-start;gap:4px;margin:0}
.crs-form .link{margin-top:2px}

/* v3.1: bảng quản trị học viên gọn, không bị cắt cột thao tác */
.page.admin{max-width:1320px}
.admin .tablewrap{overflow-x:auto}
.admin table{min-width:900px}
.admin th{white-space:nowrap;padding:12px 8px}
.admin td{padding:12px 8px}
.admin td:nth-child(1){min-width:170px;overflow-wrap:anywhere}
.admin td:nth-child(2){min-width:215px}
.admin td:nth-child(3){white-space:nowrap}
.admin td:nth-child(4),.admin td:nth-child(5){min-width:92px}
.admin td:nth-child(6),.admin th:nth-child(6){text-align:center}
.admin td.acts{min-width:190px}
.admin .acts form{display:grid;grid-template-columns:auto auto;justify-content:start;gap:6px 16px}
.admin .acts button.link{text-align:left;white-space:nowrap}
.admin .crs-form{gap:6px}
.admin .crs-form .link{margin-top:4px;font-weight:600}

/* v3.1: dưới 1200px mỗi học viên là một thẻ xếp dọc (không cuộn ngang, dùng được trên điện thoại) */
@media(max-width:1199px){
  .admin .tablewrap{overflow-x:visible}
  .admin table,.admin tbody,.admin tr,.admin td{display:block;min-width:0!important}
  .admin table{width:100%}
  .admin thead{position:absolute;left:-9999px}
  .admin tbody tr{background:var(--bg);border:1px solid var(--line);border-radius:12px;padding:12px 14px;margin:0 0 12px}
  .admin td{border:0;padding:6px 0;text-align:left!important;white-space:normal!important}
  .admin td[data-l]{display:grid;grid-template-columns:150px 1fr;gap:10px;align-items:start}
  .admin td[data-l]::before{content:attr(data-l);color:var(--dim);font-size:.8rem;text-transform:uppercase;letter-spacing:.05em;padding-top:2px}
  .admin td:nth-child(1){padding-bottom:8px;border-bottom:1px solid var(--line);margin-bottom:4px}
  .admin td.acts{padding-top:10px;border-top:1px solid var(--line);margin-top:6px}
  .admin .acts form{display:flex;flex-wrap:wrap;gap:6px 18px}
}
@media(max-width:520px){
  .admin td[data-l]{grid-template-columns:1fr;gap:2px}
}

/* v3.1: thẻ giáo án đã mở / còn khóa (kiểu mở khóa trong game) */
.tile{position:relative}
.tile .state{display:inline-flex;align-items:center;gap:6px;font-size:.78rem;font-weight:600;letter-spacing:.06em;text-transform:uppercase;margin:0 0 10px;padding:3px 10px 3px 8px;border-radius:999px}
.tile .state svg{width:15px;height:15px;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round}
.tile .state.on{background:var(--soft);color:var(--good)}
.tile .state.off{background:var(--soft);color:var(--dim)}
.tile.locked{background:repeating-linear-gradient(135deg,var(--paper),var(--paper) 10px,var(--bg) 10px,var(--bg) 20px);border-style:dashed}
.tile.locked h2,.tile.locked p{color:var(--dim)}
.tile.locked .go{color:var(--dim);font-weight:500}
.tile.locked:hover{border-color:var(--dim);transform:none}
.lockbox{max-width:520px;margin:40px auto;text-align:center;background:var(--paper);border:1px solid var(--line);border-radius:16px;padding:34px 28px}
.lockbox svg{width:44px;height:44px;fill:none;stroke:var(--dim);stroke-width:1.6;stroke-linecap:round;stroke-linejoin:round}
.lockbox h1{margin:.4em 0 .3em;font-size:1.5rem}
.lockbox .contact{font-weight:600;color:var(--accent);margin:.8em 0}