:root{
  --ink:#262329; --soft:#6b6560; --paper:#FBFAF6; --card:#ffffff;
  --cinnabar:#C0392B; --cinnabar-deep:#8E2A22; --gold:#C2912E; --jade:#2E7D6B;
  --jade-soft:#E9F3F0; --gold-soft:#FBF1DC; --red-soft:#FBEAE7;
  --line:#E7E1D6; --line-strong:#D6CDBC;
  --sidebar-w:280px; --topbar-h:64px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--paper);color:var(--ink);
  font-family:'Sarabun','Noto Sans',system-ui,sans-serif;font-size:16px;line-height:1.65;}
.pin{font-family:'Noto Sans','Sarabun',sans-serif;}
button{font-family:inherit;}
a{color:inherit;}

/* ---------------- shell layout ---------------- */
.shell{display:flex;min-height:100vh;}

.sidebar{
  width:var(--sidebar-w);flex:0 0 var(--sidebar-w);
  background:linear-gradient(180deg,#2a1210 0%,#1c0d0c 100%);
  color:#f4ece7;display:flex;flex-direction:column;
  position:sticky;top:0;height:100vh;overflow-y:auto;
  border-right:1px solid #3a1a17;z-index:80;
}
.brand{padding:22px 20px 16px;border-bottom:1px solid rgba(255,255,255,.1);}
.brand-eyebrow{font-family:'Noto Sans',sans-serif;font-size:11px;letter-spacing:.14em;text-transform:uppercase;color:#E8B4A8;margin-bottom:6px;}
.brand-title{font-size:20px;font-weight:700;color:#fff;}
.brand-sub{font-size:12.5px;color:#cdb6ad;margin-top:4px;}

.nav-section-label{padding:14px 20px 6px;font-size:11.5px;letter-spacing:.08em;text-transform:uppercase;color:#c79b8d;font-family:'Noto Sans',sans-serif;}
.nav{padding:8px 10px;display:flex;flex-direction:column;gap:3px;}

.chapter-item{border-radius:10px;overflow:hidden;}
.chapter-btn{width:100%;text-align:left;background:transparent;border:none;color:#f1e3dd;
  padding:11px 12px;cursor:pointer;display:flex;align-items:center;justify-content:space-between;gap:8px;
  font-size:14.5px;font-weight:600;border-radius:9px;transition:.15s;}
.chapter-btn:hover{background:rgba(255,255,255,.08);}
.chapter-btn.active{background:var(--cinnabar);color:#fff;}
.chapter-btn .num{display:inline-grid;place-items:center;width:22px;height:22px;border-radius:6px;background:rgba(255,255,255,.12);
  font-size:12px;font-family:'Noto Sans',sans-serif;margin-right:8px;flex:0 0 auto;}
.chapter-btn.active .num{background:rgba(255,255,255,.28);}
.chapter-btn .chev{transition:.2s;opacity:.6;font-size:11px;}
.chapter-item.open .chev{transform:rotate(90deg);}

.activity-list{max-height:0;overflow:hidden;transition:max-height .25s ease;padding-left:6px;}
.chapter-item.open .activity-list{max-height:400px;}
.activity-btn{width:100%;text-align:left;background:transparent;border:none;color:#d9c3ba;
  padding:8px 12px 8px 34px;cursor:pointer;font-size:13.5px;border-radius:8px;display:flex;align-items:center;justify-content:space-between;gap:6px;}
.activity-btn:hover{background:rgba(255,255,255,.07);color:#fff;}
.activity-btn.active{background:var(--gold-soft);color:var(--cinnabar-deep);font-weight:700;}
.activity-badge{font-family:'Noto Sans',sans-serif;font-size:11px;background:rgba(46,125,107,.25);color:#9fe0cd;
  border-radius:999px;padding:1px 7px;flex:0 0 auto;}
.activity-btn.active .activity-badge{background:var(--jade);color:#fff;}

.nav-mix .chapter-btn{background:rgba(194,145,46,.14);}
.nav-mix .chapter-btn.active{background:var(--gold);color:#3a2a06;}

.sidebar-foot{margin-top:auto;padding:16px 18px 22px;}
.btn-ghost-sm{width:100%;background:transparent;border:1px solid rgba(255,255,255,.25);color:#e9d9d2;
  border-radius:9px;padding:9px 10px;font-size:12.5px;cursor:pointer;}
.btn-ghost-sm:hover{background:rgba(255,255,255,.08);}

.sidebar-toggle{display:none;position:fixed;top:12px;left:12px;z-index:120;width:42px;height:42px;border-radius:10px;
  background:var(--cinnabar);color:#fff;border:none;font-size:19px;cursor:pointer;box-shadow:0 4px 14px -6px rgba(0,0,0,.5);}
.overlay{display:none;position:fixed;inset:0;background:rgba(0,0,0,.45);z-index:70;}

/* ---------------- main ---------------- */
.main{flex:1;min-width:0;display:flex;flex-direction:column;}
.topbar{position:sticky;top:0;z-index:60;background:rgba(251,250,246,.96);backdrop-filter:saturate(150%) blur(6px);
  border-bottom:1px solid var(--line-strong);padding:14px 28px;display:flex;align-items:center;justify-content:space-between;gap:12px;
  min-height:var(--topbar-h);flex-wrap:wrap;}
.crumb{font-weight:700;font-size:16px;color:var(--cinnabar-deep);}
.crumb .sep{color:var(--soft);font-weight:400;margin:0 6px;}
.topbar-actions{display:flex;gap:8px;flex-wrap:wrap;}

.content{padding:26px 28px 90px;max-width:980px;margin:0 auto;width:100%;}
.welcome{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:34px;text-align:center;margin-top:40px;}
.welcome h1{margin:0 0 10px;color:var(--cinnabar-deep);}

/* ---------------- generic building blocks ---------------- */
h2.block{font-size:21px;margin:26px 0 14px;font-weight:700;color:var(--ink);border-left:5px solid var(--gold);padding-left:14px;}
.lesson-head{background:var(--cinnabar);color:#fff;border-radius:14px;padding:16px 22px;margin:0 0 18px;
  display:flex;align-items:baseline;gap:12px;flex-wrap:wrap;}
.lesson-head .tag{background:#fff;color:var(--cinnabar-deep);font-weight:700;border-radius:8px;padding:5px 11px;font-size:14px;}
.lesson-head .title{font-size:19px;font-weight:700;}
.lesson-head .theme{font-size:13.5px;color:#FBDAD5;font-weight:400;}

.sub-h{font-size:15.5px;font-weight:700;color:var(--cinnabar-deep);margin:24px 0 10px;display:flex;align-items:center;gap:9px;}
.sub-h .n{display:inline-grid;place-items:center;width:23px;height:23px;border-radius:7px;background:var(--red-soft);
  color:var(--cinnabar-deep);font-size:12.5px;font-weight:700;font-family:'Noto Sans',sans-serif;}

table{width:100%;border-collapse:collapse;margin:6px 0 8px;font-size:14.5px;}
th,td{text-align:left;padding:8px 10px;border-bottom:1px solid var(--line);vertical-align:top;}
thead th{background:#FAF5EC;color:var(--soft);font-size:12.5px;font-weight:600;text-transform:uppercase;letter-spacing:.04em;
  border-bottom:2px solid var(--line-strong);font-family:'Noto Sans',sans-serif;}
td.py{font-family:'Noto Sans',sans-serif;font-weight:600;color:var(--cinnabar-deep);white-space:nowrap;}
tbody tr:nth-child(even){background:#FCFBF8;}

.pat{border:1px solid var(--line);border-left:4px solid var(--gold);border-radius:10px;padding:14px 18px;margin:12px 0;background:#fff;}
.pat .label{font-weight:700;color:var(--ink);margin-bottom:4px;}
.formula{font-family:'Noto Sans',sans-serif;background:var(--red-soft);color:var(--cinnabar-deep);
  display:inline-block;padding:6px 12px;border-radius:8px;font-weight:600;margin:6px 0;font-size:14.5px;}
.ex{margin:6px 0 0;padding-left:2px;}
.ex li{margin-bottom:6px;list-style:none;position:relative;padding-left:16px;display:flex;align-items:center;flex-wrap:wrap;gap:6px;}
.ex li::before{content:"\203A";position:absolute;left:0;color:var(--gold);font-weight:700;}
.ex .py{font-family:'Noto Sans',sans-serif;color:var(--ink);font-weight:600;}
.ex .th{color:var(--soft);}

.review{background:var(--jade-soft);border:1px solid #C9E2DB;border-radius:12px;padding:16px 20px;margin:14px 0;}
.review h4{margin:0 0 8px;color:var(--jade);font-size:15px;}
.review ul{margin:0;padding-left:20px;} .review li{margin-bottom:4px;}

.tips{background:#fff;border:1px solid var(--line);border-left:4px solid var(--cinnabar);border-radius:10px;padding:12px 18px;margin:16px 0;}
.tips h4{margin:0 0 6px;color:var(--cinnabar-deep);font-size:15px;}
.tips ul{margin:0;padding-left:20px;} .tips li{margin-bottom:5px;}

.dia{border:1px solid var(--line);border-radius:12px;padding:6px 20px 16px;margin:14px 0;background:#FCFBF8;}
.dia .scene{font-weight:600;color:var(--cinnabar-deep);margin:14px 0 8px;}
.turn{display:grid;grid-template-columns:86px 1fr;gap:10px;padding:7px 0;border-bottom:1px dotted var(--line);}
.turn:last-child{border-bottom:none;}
.turn .who{font-weight:700;color:var(--gold);font-size:13.5px;font-family:'Noto Sans',sans-serif;}
.turn .line .py{font-family:'Noto Sans',sans-serif;font-weight:600;}
.turn .line .th{color:var(--soft);font-size:13.5px;}

.spk{cursor:pointer;border:1px solid var(--line-strong);background:#fff;border-radius:7px;
  font-size:12.5px;line-height:1;padding:4px 8px;margin-left:2px;vertical-align:middle;flex:0 0 auto;}
.spk:hover{background:var(--gold-soft);border-color:var(--gold);}
.spk.playing{background:var(--jade);border-color:var(--jade);color:#fff;}

/* ---------------- activity cards ---------------- */
.card{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:24px;margin:0 0 18px;
  box-shadow:0 6px 22px -18px rgba(0,0,0,.4);}
.set-btns{display:flex;flex-wrap:wrap;gap:10px;margin-top:14px;}
.set-btns button{cursor:pointer;border:1px solid var(--line-strong);background:#fff;color:var(--cinnabar-deep);
  font-weight:600;font-size:14.5px;padding:10px 18px;border-radius:10px;}
.set-btns button:hover{background:var(--red-soft);border-color:var(--cinnabar);}
.game-meta{display:flex;justify-content:space-between;align-items:center;margin-bottom:14px;
  font-family:'Noto Sans',sans-serif;font-weight:600;color:var(--soft);font-size:13.5px;flex-wrap:wrap;gap:8px;}
.game-meta .score{color:var(--jade);}
.progress-bar{height:8px;background:var(--line);border-radius:99px;overflow:hidden;margin-bottom:18px;}
.progress-bar > i{display:block;height:100%;background:var(--gold);width:0;transition:width .3s;}
.btn-primary{cursor:pointer;border:none;background:var(--cinnabar);color:#fff;font-weight:700;font-size:14.5px;
  padding:11px 24px;border-radius:10px;}
.btn-primary:hover{background:var(--cinnabar-deep);}
.btn-secondary{cursor:pointer;border:1px solid var(--line-strong);background:#fff;color:var(--ink);font-weight:600;
  font-size:14px;padding:10px 20px;border-radius:10px;}
.btn-secondary:hover{background:var(--gold-soft);}
.hidden{display:none !important;}
.result-big{text-align:center;font-size:32px;font-weight:700;color:var(--cinnabar-deep);margin:8px 0;}
.center{text-align:center;}

/* flashcards */
.flash-wrap{display:flex;flex-direction:column;align-items:center;gap:16px;}
.flashcard{width:100%;max-width:440px;height:230px;perspective:1200px;cursor:pointer;}
.flashcard-inner{position:relative;width:100%;height:100%;transition:transform .45s;transform-style:preserve-3d;}
.flashcard.flipped .flashcard-inner{transform:rotateY(180deg);}
.flashcard-face{position:absolute;inset:0;backface-visibility:hidden;border-radius:18px;border:1px solid var(--line);
  display:flex;flex-direction:column;align-items:center;justify-content:center;gap:10px;padding:20px;text-align:center;
  background:#fff;box-shadow:0 10px 30px -18px rgba(0,0,0,.45);}
.flashcard-face.back{transform:rotateY(180deg);background:var(--jade-soft);}
.flashcard-face .big{font-size:28px;font-weight:700;font-family:'Noto Sans',sans-serif;color:var(--cinnabar-deep);}
.flashcard-face.back .big{color:var(--jade);}
.flashcard-face .small{color:var(--soft);font-size:14px;}
.flashcard-face .hint{position:absolute;bottom:12px;right:16px;font-size:11.5px;color:var(--soft);}
.flash-controls{display:flex;align-items:center;gap:14px;}
.flash-nav{cursor:pointer;border:1px solid var(--line-strong);background:#fff;border-radius:10px;padding:9px 16px;font-weight:600;}
.flash-nav:hover{background:var(--red-soft);}
.flash-count{font-family:'Noto Sans',sans-serif;color:var(--soft);font-size:13.5px;}

/* matching */
.match-grid{display:grid;grid-template-columns:1fr 1fr;gap:24px;margin-top:6px;}
@media(max-width:620px){.match-grid{grid-template-columns:1fr}}
.match-col-label{font-size:12px;text-transform:uppercase;letter-spacing:.06em;color:var(--soft);font-family:'Noto Sans',sans-serif;margin-bottom:8px;}
.match-item{border:1.5px solid var(--line-strong);background:#fff;border-radius:10px;padding:11px 14px;margin-bottom:8px;
  cursor:pointer;font-size:14.5px;transition:.12s;display:flex;align-items:center;justify-content:space-between;gap:8px;}
.match-item:hover{border-color:var(--gold);background:var(--gold-soft);}
.match-item.py{font-family:'Noto Sans',sans-serif;font-weight:600;}
.match-item.selected{border-color:var(--cinnabar);background:var(--red-soft);}
.match-item.matched{border-color:var(--jade);background:var(--jade-soft);color:var(--jade);opacity:.7;pointer-events:none;}
.match-item.wrong{animation:shake .3s;border-color:var(--cinnabar);background:#F6DEDA;}
@keyframes shake{0%,100%{transform:translateX(0)}25%{transform:translateX(-4px)}75%{transform:translateX(4px)}}

/* quiz */
.clue{text-align:center;margin:6px 0 6px;}
.clue .small{color:var(--soft);font-size:12.5px;font-family:'Noto Sans',sans-serif;text-transform:uppercase;letter-spacing:.08em;}
.clue .big{font-size:26px;font-weight:700;color:var(--ink);margin-top:6px;}
.clue .chapter-tag{display:inline-block;background:var(--gold-soft);color:var(--cinnabar-deep);border-radius:999px;
  padding:2px 10px;font-size:11.5px;font-weight:700;margin-bottom:8px;font-family:'Noto Sans',sans-serif;}
.opts{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:20px 0 8px;}
@media(max-width:560px){.opts{grid-template-columns:1fr}}
.opt{cursor:pointer;border:1.5px solid var(--line-strong);background:#fff;border-radius:12px;padding:14px 16px;
  font-family:'Noto Sans',sans-serif;font-weight:600;font-size:16px;color:var(--ink);text-align:center;transition:.12s;}
.opt:hover{border-color:var(--gold);background:var(--gold-soft);}
.opt.correct{background:var(--jade);border-color:var(--jade);color:#fff;}
.opt.wrong{background:#F6DEDA;border-color:var(--cinnabar);color:var(--cinnabar-deep);}
.opt.disabled{pointer-events:none;opacity:.9;}
.opt-top{display:flex;align-items:center;justify-content:center;gap:8px;}
.opt-th{font-family:'Sarabun',sans-serif;font-weight:400;font-size:12.5px;color:var(--soft);margin-top:5px;}
.opt.correct .opt-th{color:#e9f7f2;}
.opt.wrong .opt-th{color:var(--cinnabar-deep);}
.feedback{text-align:center;min-height:24px;font-weight:600;margin-top:6px;}
.feedback.ok{color:var(--jade);} .feedback.no{color:var(--cinnabar);}

/* typing exercise */
.type-q{background:#fff;border:1px solid var(--line);border-radius:12px;padding:18px 20px;margin-bottom:14px;}
.type-q .prompt{font-weight:600;margin-bottom:10px;}
.type-q input[type=text]{width:100%;font-family:'Noto Sans',sans-serif;font-size:15px;padding:10px 12px;
  border:1.5px solid var(--line-strong);border-radius:9px;background:#fff;color:var(--ink);}
.type-q input[type=text]:focus{outline:none;border-color:var(--gold);background:var(--gold-soft);}
.type-q .result{margin-top:10px;font-size:14px;border-radius:8px;padding:8px 12px;display:none;}
.type-q .result.show{display:block;}
.type-q .result.ok{background:var(--jade-soft);color:var(--jade);}
.type-q .result.no{background:var(--red-soft);color:var(--cinnabar-deep);}
.type-q .answer-line{font-family:'Noto Sans',sans-serif;font-weight:600;}

/* pdf */
.pdf-frame-wrap{background:#333;border-radius:16px;overflow:hidden;height:80vh;border:1px solid var(--line);}
.pdf-frame-wrap iframe{width:100%;height:100%;border:none;}

footer.appfoot{margin-top:40px;border-top:1px solid var(--line);padding-top:18px;color:var(--soft);font-size:12.5px;text-align:center;}

/* ---------------- responsive ---------------- */
@media(max-width:900px){
  .sidebar-toggle{display:block;}
  .sidebar{position:fixed;left:0;top:0;transform:translateX(-100%);transition:transform .25s ease;box-shadow:0 0 40px rgba(0,0,0,.5);}
  body.sidebar-open .sidebar{transform:translateX(0);}
  body.sidebar-open .overlay{display:block;}
  .content{padding:22px 16px 80px;}
  .topbar{padding:14px 16px 14px 60px;}
}

.version-tag{margin-top:10px;text-align:center;font-family:'Noto Sans',sans-serif;font-size:11px;color:#a98a80;letter-spacing:.04em;}

/* ---------------- login page ---------------- */
body.login-body{background:linear-gradient(135deg,#2a1210 0%,#1c0d0c 100%);min-height:100vh;
  display:flex;align-items:center;justify-content:center;padding:20px;}
.login-wrap{width:100%;max-width:420px;}
.login-card{background:var(--card);border-radius:20px;padding:36px 32px;box-shadow:0 20px 60px -20px rgba(0,0,0,.6);}
.login-eyebrow{font-family:'Noto Sans',sans-serif;font-size:11px;letter-spacing:.16em;text-transform:uppercase;
  color:var(--cinnabar-deep);font-weight:700;margin-bottom:8px;}
.login-title{margin:0 0 6px;font-size:24px;color:var(--ink);}
.login-sub{margin:0 0 22px;color:var(--soft);font-size:14px;}
.login-label{display:block;font-size:13px;font-weight:600;color:var(--soft);margin-bottom:6px;}
.login-input{width:100%;font-family:'Noto Sans',sans-serif;font-size:18px;letter-spacing:.06em;text-align:center;
  padding:13px 14px;border:1.5px solid var(--line-strong);border-radius:10px;background:#fff;color:var(--ink);margin-bottom:16px;}
.login-input:focus{outline:none;border-color:var(--gold);background:var(--gold-soft);}
.login-btn{width:100%;padding:13px;font-size:15.5px;}
.login-error{margin-top:14px;background:var(--red-soft);color:var(--cinnabar-deep);border-radius:9px;padding:10px 14px;font-size:13.5px;text-align:center;}
.login-hint{text-align:center;color:var(--soft);font-size:12.5px;margin:20px 0 0;}

/* ---------------- auth bar in sidebar ---------------- */
.auth-bar{padding:12px 18px;border-top:1px solid rgba(255,255,255,.1);border-bottom:1px solid rgba(255,255,255,.1);
  display:flex;align-items:center;justify-content:space-between;gap:8px;}
.auth-bar .who{font-size:12.5px;color:#f1e3dd;line-height:1.4;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;}
.auth-bar .who .role{display:block;font-size:11px;color:#c79b8d;text-transform:uppercase;letter-spacing:.05em;}
.auth-bar button{flex:0 0 auto;background:transparent;border:1px solid rgba(255,255,255,.25);color:#e9d9d2;
  border-radius:8px;padding:6px 10px;font-size:12px;cursor:pointer;}
.auth-bar button:hover{background:rgba(255,255,255,.08);}
.admin-link{display:block;margin:8px 18px 0;text-align:center;text-decoration:none;background:var(--gold);color:#3a2a06;
  border-radius:9px;padding:9px 10px;font-size:13px;font-weight:700;}
.admin-link:hover{background:#d6a53a;}

/* ---------------- overview page ---------------- */
.callout{background:var(--gold-soft);border:1px solid #EEDDB6;border-radius:12px;padding:16px 20px;margin:18px 0;}
.callout strong{color:var(--cinnabar-deep);}
.stat-row{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin:18px 0;}
@media(max-width:700px){.stat-row{grid-template-columns:repeat(2,1fr);}}
.stat-card{background:#fff;border:1px solid var(--line);border-radius:12px;padding:16px;text-align:center;}
.stat-card .num{font-size:26px;font-weight:700;color:var(--cinnabar-deep);}
.stat-card .lbl{font-size:12.5px;color:var(--soft);margin-top:4px;}
.chapter-card-grid{display:grid;grid-template-columns:1fr;gap:10px;margin:16px 0;}
.chapter-card{display:flex;align-items:flex-start;gap:14px;background:#fff;border:1px solid var(--line);
  border-left:4px solid var(--gold);border-radius:12px;padding:14px 18px;text-decoration:none;color:var(--ink);cursor:pointer;transition:.15s;}
.chapter-card:hover{border-left-color:var(--cinnabar);background:var(--red-soft);}
.chapter-card .num{flex:0 0 auto;width:36px;height:36px;border-radius:10px;background:var(--red-soft);color:var(--cinnabar-deep);
  display:grid;place-items:center;font-weight:700;font-family:'Noto Sans',sans-serif;}
.chapter-card .info .ttl{font-weight:700;margin-bottom:2px;}
.chapter-card .info .desc{font-size:13px;color:var(--soft);}

/* ---------------- admin page ---------------- */
.admin-body{margin:0;background:var(--paper);color:var(--ink);font-family:'Sarabun','Noto Sans',system-ui,sans-serif;}
.admin-wrap{max-width:900px;margin:0 auto;padding:26px 24px 90px;}
.admin-topbar{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-bottom:20px;flex-wrap:wrap;}
.admin-topbar h1{font-size:22px;color:var(--cinnabar-deep);margin:0;}
.key-table-wrap{overflow-x:auto;}
.key-row-active{color:var(--jade);font-weight:700;}
.key-row-inactive{color:var(--soft);}
.key-form{display:grid;grid-template-columns:1fr 1fr 140px;gap:10px;align-items:end;margin-bottom:18px;}
@media(max-width:640px){.key-form{grid-template-columns:1fr;}}
.key-form .field label{display:block;font-size:12.5px;font-weight:600;color:var(--soft);margin-bottom:5px;}
.key-form .field input,.key-form .field select{width:100%;font-family:'Sarabun',sans-serif;font-size:14.5px;
  padding:9px 12px;border:1.5px solid var(--line-strong);border-radius:9px;background:#fff;color:var(--ink);}
.key-actions{display:flex;gap:6px;flex-wrap:wrap;}
.key-actions button{cursor:pointer;border:1px solid var(--line-strong);background:#fff;border-radius:7px;
  font-size:12.5px;padding:5px 10px;}
.key-actions button:hover{background:var(--gold-soft);border-color:var(--gold);}
.key-actions button.danger:hover{background:#F6DEDA;border-color:var(--cinnabar);color:var(--cinnabar-deep);}
code.key-code{font-family:'Noto Sans',sans-serif;background:var(--gold-soft);padding:3px 8px;border-radius:6px;letter-spacing:.04em;}