/* ===== LMS QLGD - Ứng dụng CNTT trong giáo dục ===== */
:root{
  --primary:#1d4ed8;
  --primary-dark:#1e3a8a;
  --primary-light:#dbeafe;
  --accent:#f59e0b;
  --success:#16a34a;
  --danger:#dc2626;
  --bg:#f6f8fb;
  --surface:#ffffff;
  --text:#1f2937;
  --text-muted:#6b7280;
  --border:#e5e7eb;
  --radius:12px;
  --shadow:0 1px 3px rgba(16,24,40,.08),0 1px 2px rgba(16,24,40,.06);
  --shadow-md:0 4px 12px rgba(16,24,40,.10);
  font-size:16px;
}
*{box-sizing:border-box;}
html,body{margin:0;padding:0;}
body{
  font-family:"Segoe UI",Roboto,Inter,Arial,sans-serif;
  background:var(--bg);
  color:var(--text);
  line-height:1.7;
  -webkit-font-smoothing:antialiased;
}
a{color:var(--primary);text-decoration:none;}
a:hover{text-decoration:underline;}
img{max-width:100%;}

/* ---------- Password gate ---------- */
#pw-gate{
  position:fixed;inset:0;background:linear-gradient(135deg,#1e3a8a,#1d4ed8 55%,#0ea5e9);
  display:flex;align-items:center;justify-content:center;z-index:9999;padding:20px;
}
#pw-gate.hidden{display:none;}
.pw-card{
  background:#fff;border-radius:16px;padding:36px 32px;max-width:400px;width:100%;
  box-shadow:0 20px 60px rgba(0,0,0,.35);text-align:center;
}
.pw-card .pw-logo{font-size:40px;margin-bottom:8px;}
.pw-card h1{font-size:20px;margin:0 0 4px;color:var(--primary-dark);}
.pw-card p.sub{color:var(--text-muted);font-size:14px;margin-top:0;margin-bottom:20px;}
.pw-card input[type=password]{
  width:100%;padding:12px 14px;border:1.5px solid var(--border);border-radius:10px;
  font-size:15px;margin-bottom:12px;text-align:center;letter-spacing:2px;
}
.pw-card input[type=password]:focus{outline:none;border-color:var(--primary);}
.pw-card button{
  width:100%;padding:12px;border:none;border-radius:10px;background:var(--primary);
  color:#fff;font-size:15px;font-weight:600;cursor:pointer;transition:.15s;
}
.pw-card button:hover{background:var(--primary-dark);}
.pw-error{color:var(--danger);font-size:13px;min-height:18px;margin-top:8px;}
.pw-hint{font-size:12px;color:var(--text-muted);margin-top:16px;line-height:1.5;}

/* ---------- Layout ---------- */
.app{display:flex;min-height:100vh;}
.sidebar{
  width:270px;flex-shrink:0;background:var(--primary-dark);color:#fff;
  position:sticky;top:0;height:100vh;overflow-y:auto;padding:20px 0 30px;
  transition:transform .25s ease;z-index:500;
}
.sidebar .brand{
  display:flex;align-items:center;gap:10px;padding:0 20px 18px;
  border-bottom:1px solid rgba(255,255,255,.15);margin-bottom:14px;
}
.sidebar .brand .logo-emoji{font-size:26px;}
.sidebar .brand div b{display:block;font-size:15px;}
.sidebar .brand div span{display:block;font-size:11px;opacity:.75;}
.sidebar nav .nav-section{
  padding:10px 20px 6px;font-size:11px;text-transform:uppercase;letter-spacing:.06em;
  color:rgba(255,255,255,.55);font-weight:700;
}
.sidebar nav a{
  display:flex;align-items:center;gap:10px;padding:10px 20px;color:rgba(255,255,255,.85);
  font-size:14.5px;border-left:3px solid transparent;
}
.sidebar nav a:hover{background:rgba(255,255,255,.08);text-decoration:none;}
.sidebar nav a.active{background:rgba(255,255,255,.14);border-left-color:var(--accent);color:#fff;font-weight:600;}
.sidebar nav a .chk{
  width:18px;height:18px;border-radius:50%;border:1.5px solid rgba(255,255,255,.4);
  flex-shrink:0;display:flex;align-items:center;justify-content:center;font-size:11px;
}
.sidebar nav a .chk.done{background:var(--success);border-color:var(--success);}
.sidebar-close{display:none;}

.main{flex:1;min-width:0;}
.topbar{
  position:sticky;top:0;z-index:200;background:var(--surface);border-bottom:1px solid var(--border);
  display:flex;align-items:center;justify-content:space-between;padding:12px 24px;gap:12px;
}
.topbar .menu-btn{display:none;background:none;border:none;font-size:22px;cursor:pointer;color:var(--primary-dark);}
.topbar .title{font-weight:700;color:var(--primary-dark);font-size:15px;}
.topbar .progress-mini{display:flex;align-items:center;gap:8px;font-size:13px;color:var(--text-muted);}
.progress-track{width:120px;height:8px;background:var(--border);border-radius:6px;overflow:hidden;}
.progress-fill{height:100%;background:linear-gradient(90deg,var(--primary),var(--accent));border-radius:6px;transition:width .3s;}

.container{max-width:920px;margin:0 auto;padding:32px 24px 80px;}
.page-hero{
  background:linear-gradient(135deg,var(--primary-dark),var(--primary));color:#fff;
  border-radius:var(--radius);padding:32px 30px;margin-bottom:28px;box-shadow:var(--shadow-md);
}
.page-hero h1{margin:0 0 8px;font-size:24px;color:#fff;}
.page-hero p{margin:0;opacity:.95;font-size:14.5px;color:#fff;}
.badge{
  display:inline-block;background:rgba(255,255,255,.18);padding:4px 10px;border-radius:20px;
  font-size:12px;margin-right:6px;margin-bottom:6px;
}

.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:24px 26px;box-shadow:var(--shadow);margin-bottom:22px;}
.card h2{margin-top:0;}

h1,h2,h3{color:var(--primary-dark);}
.section-h2{font-size:21px;margin-top:38px;padding-top:14px;border-top:2px solid var(--primary-light);}
.section-h3{font-size:17px;margin-top:24px;color:#1e40af;}
.chapter-meta{
  display:inline-block;background:var(--primary-light);color:var(--primary-dark);
  font-size:13px;padding:8px 14px;border-radius:8px;white-space:pre-line;font-weight:600;
}
p{margin:0 0 14px;color:#374151;text-align:justify;}

/* Callouts */
.callout{border-radius:10px;padding:16px 18px;margin:18px 0;border:1px solid transparent;}
.callout p:last-child{margin-bottom:0;}
.callout-title{font-weight:700;margin-bottom:8px;font-size:14.5px;}
.callout-objective{background:#fff7ed;border-color:#fed7aa;}
.callout-objective .callout-title{color:#c2410c;}
.callout-discussion{background:#eff6ff;border-color:#bfdbfe;}
.callout-discussion .callout-title{color:#1d4ed8;}
.callout-situation{background:#fefce8;border-color:#fde68a;}
.callout-situation .callout-title{color:#a16207;}
.callout-example{background:#f0fdf4;border-color:#bbf7d0;}
.callout-example .callout-title{color:#15803d;}
.callout-deliverable{background:#fdf2f8;border-color:#fbcfe8;}
.callout-deliverable .callout-title{color:#be185d;}
.callout-summary{background:#f5f3ff;border-color:#ddd6fe;}
.callout-summary .callout-title{color:#6d28d9;}

.qa-list{padding-left:22px;}
.qa-list li{margin-bottom:10px;color:#374151;}

.chapter-nav{display:flex;justify-content:space-between;gap:12px;margin-top:36px;flex-wrap:wrap;}
.chapter-nav a{
  flex:1;min-width:180px;background:var(--surface);border:1px solid var(--border);border-radius:10px;
  padding:14px 16px;font-size:14px;color:var(--text);box-shadow:var(--shadow);
}
.chapter-nav a:hover{border-color:var(--primary);text-decoration:none;}
.chapter-nav a small{display:block;color:var(--text-muted);font-size:11.5px;text-transform:uppercase;letter-spacing:.04em;margin-bottom:3px;}
.chapter-nav a.next{text-align:right;}

.mark-complete-bar{
  display:flex;align-items:center;justify-content:space-between;gap:14px;flex-wrap:wrap;
  background:var(--surface);border:1px solid var(--border);border-radius:10px;padding:14px 18px;margin-top:30px;
  box-shadow:var(--shadow);
}
.btn{
  display:inline-block;background:var(--primary);color:#fff;border:none;border-radius:8px;
  padding:10px 18px;font-size:14px;font-weight:600;cursor:pointer;transition:.15s;
}
.btn:hover{background:var(--primary-dark);text-decoration:none;color:#fff;}
.btn.btn-outline{background:none;color:var(--primary);border:1.5px solid var(--primary);}
.btn.btn-outline:hover{background:var(--primary-light);color:var(--primary-dark);}
.btn.btn-success{background:var(--success);}
.btn.btn-success:hover{background:#15803d;}
.btn.btn-accent{background:var(--accent);}
.btn.btn-accent:hover{background:#b45309;}
.btn[disabled]{opacity:.5;cursor:not-allowed;}

/* Home grid */
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:18px;}
.ch-card{
  background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);
  padding:20px 22px;box-shadow:var(--shadow);display:flex;flex-direction:column;gap:8px;position:relative;
}
.ch-card .ch-num{
  position:absolute;top:16px;right:18px;font-size:12px;font-weight:700;color:#fff;
  background:var(--primary);padding:3px 10px;border-radius:20px;
}
.ch-card h3{margin:0 0 4px;font-size:16px;padding-right:60px;}
.ch-card p{font-size:13.5px;color:var(--text-muted);margin-bottom:6px;text-align:left;}
.ch-card .ch-progress{font-size:12px;color:var(--success);font-weight:600;}
.ch-card .btn{align-self:flex-start;margin-top:6px;}

.clo-list{padding-left:0;list-style:none;}
.clo-list li{
  display:flex;gap:12px;margin-bottom:12px;padding:12px 14px;background:#f9fafb;border-radius:8px;
  border-left:3px solid var(--primary);
}
.clo-list b{color:var(--primary-dark);flex-shrink:0;}

table.info-table{width:100%;border-collapse:collapse;margin:14px 0;font-size:14px;}
table.info-table td,table.info-table th{border:1px solid var(--border);padding:9px 12px;text-align:left;}
table.info-table th{background:var(--primary-light);color:var(--primary-dark);}

/* Quiz */
.quiz-box{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:26px 28px;margin-top:30px;box-shadow:var(--shadow);}
.quiz-box h2{margin-top:0;}
.quiz-q{margin-bottom:22px;padding-bottom:18px;border-bottom:1px dashed var(--border);}
.quiz-q:last-of-type{border-bottom:none;}
.quiz-q .q-text{font-weight:600;margin-bottom:10px;color:#111827;}
.quiz-q .q-options label{
  display:block;padding:9px 12px;border:1.5px solid var(--border);border-radius:8px;margin-bottom:8px;
  cursor:pointer;font-size:14.5px;transition:.12s;
}
.quiz-q .q-options label:hover{border-color:var(--primary);background:var(--primary-light);}
.quiz-q .q-options input{margin-right:8px;}
.quiz-q .q-options label.correct{border-color:var(--success);background:#f0fdf4;}
.quiz-q .q-options label.incorrect{border-color:var(--danger);background:#fef2f2;}
.quiz-q .explain{display:none;margin-top:8px;font-size:13.5px;background:#f9fafb;padding:10px 12px;border-radius:8px;color:var(--text-muted);}
.quiz-result{
  margin-top:20px;padding:18px 20px;border-radius:10px;background:var(--primary-light);
  font-weight:700;color:var(--primary-dark);font-size:16px;text-align:center;
}
.quiz-progress-note{font-size:13px;color:var(--text-muted);margin-bottom:16px;}

/* Exam pages */
.steps{counter-reset:step;list-style:none;padding:0;}
.steps li{
  counter-increment:step;position:relative;padding-left:42px;margin-bottom:16px;
}
.steps li::before{
  content:counter(step);position:absolute;left:0;top:0;width:28px;height:28px;border-radius:50%;
  background:var(--primary);color:#fff;font-weight:700;font-size:13px;display:flex;align-items:center;justify-content:center;
}
.deadline-box{
  display:flex;align-items:center;gap:14px;background:#fff1f2;border:1px solid #fecdd3;border-radius:10px;
  padding:16px 18px;margin:20px 0;
}
.deadline-box .icon{font-size:28px;}
.deadline-box b{color:#be123c;font-size:16px;}

.rubric-table{width:100%;border-collapse:collapse;margin-top:14px;font-size:13.5px;}
.rubric-table th,.rubric-table td{border:1px solid var(--border);padding:10px 12px;text-align:left;vertical-align:top;}
.rubric-table th{background:var(--primary-light);color:var(--primary-dark);}

footer.site-footer{text-align:center;color:var(--text-muted);font-size:12.5px;padding:26px 20px 40px;}

/* ---------- Bộ công cụ AI (bo-cong-cu-ai.php) ---------- */
.part-title{
  font-size:19px;text-transform:uppercase;letter-spacing:.03em;color:var(--primary-dark);
  margin:40px 0 14px;padding-bottom:10px;border-bottom:3px solid var(--accent);
}
.toolkit-nav{display:flex;align-items:center;gap:8px;flex-wrap:wrap;padding:18px 22px;}
.toolkit-nav b{color:var(--text-muted);font-size:13px;margin-right:4px;}
.pill{
  display:inline-block;background:var(--primary-light);color:var(--primary-dark);
  font-size:13px;font-weight:600;padding:6px 14px;border-radius:20px;border:1px solid transparent;
}
.pill:hover{background:var(--primary);color:#fff;text-decoration:none;}

.toolkit-controls{display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap;margin-bottom:16px;}
.btn.btn-sm{padding:6px 12px;font-size:12.5px;}

/* Prompt cards (Phần I) */
.prompt-card{border:1px solid var(--border);border-radius:10px;margin-bottom:12px;background:var(--surface);overflow:hidden;}
.prompt-card summary{
  cursor:pointer;padding:13px 18px;font-size:14.5px;list-style:none;background:#f9fafb;
  display:flex;gap:10px;align-items:baseline;
}
.prompt-card summary::-webkit-details-marker{display:none;}
.prompt-card summary::before{content:'▸';color:var(--primary);font-weight:700;flex-shrink:0;}
.prompt-card[open] summary::before{content:'▾';}
.prompt-card[open] summary{border-bottom:1px solid var(--border);}
.prompt-card .prompt-num{color:var(--primary);font-weight:700;flex-shrink:0;white-space:nowrap;}
.prompt-card .prompt-title{color:var(--text);font-weight:600;}
.prompt-card .prompt-body{padding:16px 18px 18px;}
.prompt-meta{font-size:13.5px;color:var(--text-muted);margin-bottom:12px;text-align:left;}
.prompt-text{position:relative;background:#eff6ff;border:1px solid #bfdbfe;border-radius:8px;padding:16px 100px 16px 16px;margin-bottom:12px;}
.prompt-text p{color:#1e3a8a;font-style:italic;margin:0;text-align:left;}
.copy-btn{
  position:absolute;top:10px;right:10px;font-size:12px;padding:5px 10px;border-radius:6px;
  border:1px solid #93c5fd;background:#fff;color:var(--primary-dark);cursor:pointer;font-weight:600;
}
.copy-btn:hover{background:var(--primary);color:#fff;border-color:var(--primary);}
.copy-btn.copied{background:var(--success);color:#fff;border-color:var(--success);}
.prompt-note{font-size:13.5px;color:var(--text-muted);background:#f9fafb;padding:10px 12px;border-radius:8px;margin:0;text-align:left;}

/* Project cards (Phần II) */
.project-card{border:1px solid var(--border);border-radius:10px;padding:20px 22px;margin-bottom:18px;background:var(--surface);}
.project-head{display:flex;align-items:center;gap:12px;margin-bottom:10px;flex-wrap:wrap;}
.project-code{background:var(--accent);color:#fff;font-weight:700;font-size:12.5px;padding:4px 12px;border-radius:20px;flex-shrink:0;}
.project-head h3{margin:0;font-size:16.5px;color:var(--primary-dark);}
.callout-legal{background:#f8fafc;border-color:#e2e8f0;margin-top:14px;margin-bottom:0;}
.callout-legal p{font-size:13.5px;color:#475569;text-align:left;}

.ref-list{padding-left:22px;}
.ref-list li{margin-bottom:10px;color:#374151;font-size:14.5px;}
.ref-note{font-size:13px;color:var(--text-muted);background:#f9fafb;padding:10px 12px;border-radius:8px;}

@media (max-width:600px){
  .prompt-text{padding:16px 16px 44px;}
  .copy-btn{top:auto;bottom:10px;right:10px;}
}

@media (max-width:900px){
  .sidebar{position:fixed;left:0;top:0;transform:translateX(-100%);box-shadow:0 0 30px rgba(0,0,0,.3);}
  .sidebar.open{transform:translateX(0);}
  .topbar .menu-btn{display:block;}
  .sidebar-close{display:block;position:absolute;top:16px;right:16px;background:none;border:none;color:#fff;font-size:20px;}
  .overlay{position:fixed;inset:0;background:rgba(0,0,0,.4);z-index:400;display:none;}
  .overlay.show{display:block;}
}
@media (max-width:600px){
  .container{padding:20px 16px 60px;}
  .page-hero{padding:24px 20px;}
  .card{padding:18px 18px;}
}