/* ============================================================
   ACCESSIBILITY UTILITIES
   ============================================================ */
.sr-only{
  position:absolute; width:1px; height:1px; padding:0; margin:-1px;
  overflow:hidden; clip:rect(0,0,0,0); white-space:nowrap; border:0;
}
.skip-link{
  position:absolute; left:8px; top:-60px; z-index:1000;
  background:#12324B; color:#fff; padding:10px 18px; border-radius:8px;
  font-family:'Inter', sans-serif; font-size:13px; font-weight:600;
  text-decoration:none; transition:top .15s ease;
}
.skip-link:focus{ top:8px; }
:focus-visible{
  outline:2.5px solid #0592D0; outline-offset:2px; border-radius:4px;
}
button:focus-visible, .nav-lesson-btn:focus-visible, .nav-module-btn:focus-visible,
.quiz-opt:focus-visible, .toc-chip:focus-visible, .module-card:focus-visible,
.lab-card:focus-visible, .exam-nav-cell:focus-visible{
  outline:2.5px solid #0592D0; outline-offset:1px;
}
@media (prefers-reduced-motion: reduce){
  *, *::before, *::after{
    animation-duration:0.01ms !important; animation-iteration-count:1 !important;
    transition-duration:0.01ms !important; scroll-behavior:auto !important;
  }
}

/* ============================================================
   CCNA PRACTICAL LAB ACADEMY — Ekere Labs
   Design: "Patch Panel" — light, technical, readable.
   Signature element: the numbered "port strip" rail used for
   step-by-step CLI instructions, echoing a physical patch panel,
   plus a hairline circuit-trace pattern in the sidebar header.
   ============================================================ */

:root{
  /* Font stacks use system fonts only — this file is fully self-contained and
     works offline with zero external network dependencies. */
  /* Color tokens */
  --bg:            #F6F8FA;
  --bg-soft:       #EFF3F6;
  --surface:       #FFFFFF;
  --surface-2:     #FBFCFD;
  --border:        #DCE3EA;
  --border-soft:   #E9EEF2;

  --ink:           #17232F;
  --ink-soft:      #47586A;
  --ink-faint:     #8496A6;

  --cisco-blue:    #0592D0;
  --cisco-blue-dk: #05699A;
  --navy:          #12324B;
  --navy-soft:     #1D4863;

  --accent-teal:   #0EA5A0;
  --accent-amber:  #C9781E;
  --accent-red:    #C0392B;
  --accent-green:  #2E8B57;
  --accent-purple: #6D5DD3;

  --code-bg:       #0F2436;
  --code-ink:      #CFE8F5;
  --code-accent:   #6FD3C7;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;

  --shadow-sm: 0 1px 2px rgba(18,50,75,0.06);
  --shadow-md: 0 6px 20px rgba(18,50,75,0.08);
  --shadow-lg: 0 16px 40px rgba(18,50,75,0.14);

  --font-display: 'Sora', 'Segoe UI', -apple-system, BlinkMacSystemFont, Roboto, sans-serif;
  --font-body: 'Inter', 'Segoe UI', -apple-system, BlinkMacSystemFont, Roboto, Arial, sans-serif;
  --font-mono: 'JetBrains Mono', 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
}

html.dark{
  --bg:            #0B1620;
  --bg-soft:       #0F1E2B;
  --surface:       #122736;
  --surface-2:     #0F2130;
  --border:        #1E3547;
  --border-soft:   #1A2E3D;

  --ink:           #E7F1F7;
  --ink-soft:      #AFC4D3;
  --ink-faint:     #6F8798;

  --code-bg:       #071620;
  --code-ink:      #BFE6F2;
}

*{box-sizing:border-box;}
html,body{margin:0;padding:0; max-width:100%; overflow-x:hidden;}
body{
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--ink);
  -webkit-font-smoothing: antialiased;
  min-height:100vh;
  overflow-x:hidden;
}
h1,h2,h3,h4,.font-display{font-family: var(--font-display);}
a{color:inherit;}
::selection{background: var(--cisco-blue); color:#fff;}

/* Scrollbars */
::-webkit-scrollbar{width:10px;height:10px;}
::-webkit-scrollbar-track{background:transparent;}
::-webkit-scrollbar-thumb{background:var(--border);border-radius:8px;}
::-webkit-scrollbar-thumb:hover{background:var(--ink-faint);}

/* ============ App Shell ============ */
#app{display:flex; min-height:100vh;}

/* ---------- Sidebar ---------- */
.sidebar{
  width:300px; min-width:300px;
  background: linear-gradient(180deg, var(--navy) 0%, #0E2A3F 100%);
  color:#DCEAF3;
  display:flex; flex-direction:column;
  position:sticky; top:0; height:100vh;
  z-index:40;
  transition: transform .25s ease;
}
/* ---------- Practical Exam Academy ---------- */
.pea-hero{background:linear-gradient(135deg,#0B1F14 0%,#0E3A2E 55%,#0B2A38 100%); border-radius:20px; padding:38px 36px; color:#fff; position:relative; overflow:hidden; margin-bottom:26px;}
.pea-hero::after{content:""; position:absolute; right:-40px; top:-40px; width:280px; height:280px; border-radius:50%; background:radial-gradient(circle, rgba(111,211,199,0.18), transparent 70%);}
.pea-tier-row{display:flex; gap:8px; flex-wrap:wrap; margin:18px 0 6px;}
.pea-tier-chip{font-size:10.5px; font-weight:700; text-transform:uppercase; letter-spacing:.05em; padding:5px 12px; border-radius:20px; background:rgba(255,255,255,0.1); color:#B9E8D8;}

.roadmap{display:flex; flex-direction:column; gap:0; margin:8px 0 24px;}
.roadmap-step{display:flex; align-items:center; gap:14px; padding:10px 0; position:relative;}
.roadmap-step::before{content:""; position:absolute; left:15px; top:-2px; bottom:-2px; width:2px; background:var(--border);}
.roadmap-step:first-child::before{top:50%;}
.roadmap-step:last-child::before{bottom:50%;}
.roadmap-dot{width:32px;height:32px;border-radius:50%; background:var(--surface); border:2px solid var(--border); display:flex;align-items:center;justify-content:center; font-size:13px; flex-shrink:0; position:relative; z-index:1;}
.roadmap-dot.done{background:var(--accent-green); border-color:var(--accent-green); color:#fff;}
.roadmap-dot.current{background:var(--cisco-blue); border-color:var(--cisco-blue); color:#fff; box-shadow:0 0 0 4px rgba(5,146,208,0.18);}
.roadmap-label{font-size:13px; font-weight:600; color:var(--ink-soft);}
.roadmap-label.future{color:var(--ink-faint);}

.lab-grid{display:grid; grid-template-columns:repeat(auto-fill,minmax(230px,1fr)); gap:14px;}
.lab-card{background:var(--surface); border:1px solid var(--border); border-radius:14px; padding:16px 16px; cursor:pointer; position:relative;}
.lab-card:hover{border-color:var(--cisco-blue); box-shadow:var(--shadow-md); transform:translateY(-2px);}
.lab-card .labnum{width:30px;height:30px;border-radius:8px; background:var(--navy); color:var(--code-accent); font-family:var(--font-mono); font-weight:700; font-size:12px; display:flex;align-items:center;justify-content:center; margin-bottom:10px;}
.lab-card h4{font-size:13.5px; margin:0 0 6px;}
.lab-card p{font-size:11.5px; color:var(--ink-faint); margin:0 0 10px; line-height:1.4; min-height:32px;}
.lab-card .labmeta{display:flex; justify-content:space-between; align-items:center; font-size:10.5px;}
.lab-card.done{border-color:rgba(46,139,87,0.4); background:rgba(46,139,87,0.03);}
.lab-card .flagship-badge{position:absolute; top:12px; right:12px; font-size:13px;}

.soc-panel{background:#0B1F2B; border:1px solid #164256; border-radius:14px; padding:18px 20px; margin:14px 0; color:#CFE8F5;}
.soc-panel h4{margin:0 0 10px; font-size:13.5px; display:flex; align-items:center; gap:8px; color:#6FD3C7;}
.soc-panel .lesson-prose{color:#B7CEDE;}
.soc-proto-grid{display:grid; grid-template-columns:repeat(auto-fill,minmax(150px,1fr)); gap:8px; margin-top:10px;}
.soc-proto-chip{background:rgba(111,211,199,0.08); border:1px solid rgba(111,211,199,0.25); border-radius:8px; padding:8px 10px; font-size:11.5px;}
.soc-proto-chip b{display:block; color:#6FD3C7; font-family:var(--font-mono); font-size:11px; margin-bottom:3px;}

.bt-panel{background:#1F0F14; border:1px solid #4A1F28; border-radius:14px; padding:18px 20px; margin:14px 0; color:#F0D8DC;}
.bt-panel h4{margin:0 0 10px; font-size:13.5px; display:flex; align-items:center; gap:8px; color:#E8919E;}
.bt-panel .lesson-prose{color:#D9B8BE;}
.mitre-chip{display:inline-block; background:rgba(232,145,158,0.12); border:1px solid rgba(232,145,158,0.3); color:#E8919E; font-family:var(--font-mono); font-size:11px; padding:3px 9px; border-radius:6px; margin:3px 4px 3px 0;}

.realworld-panel{background:var(--surface-2); border:1px solid var(--border-soft); border-radius:14px; padding:18px 20px; margin:14px 0;}
.realworld-panel h4{margin:0 0 10px; font-size:13.5px; color:var(--cisco-blue-dk);}

.fault-card{background:rgba(192,57,43,0.05); border:1px solid rgba(192,57,43,0.25); border-radius:12px; padding:14px 16px; margin-bottom:10px;}
.fault-card b{color:var(--accent-red); font-size:11.5px; text-transform:uppercase; letter-spacing:.04em; display:block; margin-bottom:4px;}

.sidebar-brand{
  padding:22px 20px 18px 20px;
  border-bottom:1px solid rgba(255,255,255,0.08);
  position:relative;
  overflow:hidden;
}
.sidebar-brand::before{
  content:"";
  position:absolute; inset:0;
  background-image:
    repeating-linear-gradient(90deg, rgba(111,211,199,0.08) 0 1px, transparent 1px 26px),
    repeating-linear-gradient(0deg, rgba(111,211,199,0.08) 0 1px, transparent 1px 26px);
  mask-image: linear-gradient(180deg, black, transparent);
  pointer-events:none;
}
.brand-row{display:flex; align-items:center; gap:10px; position:relative;}
.brand-mark{
  width:38px;height:38px;border-radius:10px;
  background: linear-gradient(135deg, var(--cisco-blue), var(--accent-teal));
  display:flex;align-items:center;justify-content:center;
  font-family:var(--font-display); font-weight:800; color:#fff; font-size:15px;
  box-shadow: var(--shadow-md);
  flex-shrink:0;
}
.brand-name{font-family:var(--font-display); font-weight:700; font-size:15.5px; line-height:1.2; color:#fff;}
.brand-sub{font-size:10.5px; color:#7FB8D6; letter-spacing:.06em; text-transform:uppercase; margin-top:2px;}
.brand-tagline{font-size:11.5px; color:#9FC1D6; margin-top:10px; position:relative; line-height:1.5;}

.sidebar-search{padding:14px 16px 8px; position:relative;}
.sidebar-search input{
  width:100%; background:rgba(255,255,255,0.07); border:1px solid rgba(255,255,255,0.12);
  color:#fff; padding:9px 12px 9px 34px; border-radius:8px; font-size:13px; font-family:var(--font-body);
  background-image: none;
}
.sidebar-search-wrap{position:relative;}
.sidebar-search-wrap svg{position:absolute; left:10px; top:50%; transform:translateY(-50%); opacity:.6;}
.sidebar-search input::placeholder{color:#8FB4CB;}
.sidebar-search input:focus{outline:2px solid var(--accent-teal); background:rgba(255,255,255,0.1);}

.sidebar-nav{flex:1; overflow-y:auto; padding:10px 10px 16px;}
.sidebar-nav-toggle-row{display:flex; justify-content:flex-end; padding:2px 4px 10px;}
.sidebar-expand-toggle{background:rgba(255,255,255,0.06); border:1px solid rgba(255,255,255,0.14); color:#B7CEDE; font-size:11px; font-weight:600; padding:5px 11px; border-radius:20px; cursor:pointer;}
.sidebar-expand-toggle:hover{background:rgba(255,255,255,0.12); color:#fff;}
.nav-section{margin-bottom:4px;}
.nav-module-btn{
  width:100%; display:flex; align-items:center; gap:10px;
  padding:10px 10px; border:none; background:transparent; color:#D7E7F1;
  cursor:pointer; border-radius:8px; font-size:13.5px; font-family:var(--font-body); font-weight:600;
  text-align:left;
}
.nav-module-btn:hover{background:rgba(255,255,255,0.06);}
.nav-module-btn.open{background:rgba(255,255,255,0.08); color:#fff;}
.nav-module-num{
  width:24px;height:24px;border-radius:6px;background:rgba(111,211,199,0.15);
  color:var(--code-accent); font-size:11px; font-family:var(--font-mono); font-weight:700;
  display:flex;align-items:center;justify-content:center; flex-shrink:0;
}
.nav-module-chev{margin-left:auto; transition:transform .18s ease; opacity:.6; flex-shrink:0;}
.nav-module-btn.open .nav-module-chev{transform:rotate(90deg);}
.nav-module-progress{height:3px; background:rgba(255,255,255,0.1); border-radius:2px; margin:3px 10px 8px; overflow:hidden;}
.nav-module-progress i{display:block; height:100%; background:linear-gradient(90deg,var(--cisco-blue),var(--accent-teal));}

.nav-lessons{max-height:0; overflow:hidden; transition:max-height .25s ease;}
.nav-lessons.open{max-height:1400px;}
.nav-lesson-btn{
  width:100%; display:flex; align-items:center; gap:8px;
  padding:7px 10px 7px 42px; border:none; background:transparent; color:#B7CEDE;
  cursor:pointer; border-radius:6px; font-size:12.5px; font-family:var(--font-body); text-align:left;
}
.nav-lesson-btn:hover{background:rgba(255,255,255,0.06); color:#fff;}
.nav-lesson-btn.active{background:rgba(5,146,208,0.25); color:#fff; font-weight:600;}
.nav-lesson-dot{width:7px;height:7px;border-radius:50%; background:#3A5A70; flex-shrink:0;}
.nav-lesson-dot.done{background:var(--accent-green);}
.nav-lesson-dot.flagship{background:var(--accent-teal); box-shadow:0 0 0 3px rgba(14,165,160,0.2);}
.nav-lesson-label{flex:1; overflow:hidden; text-overflow:ellipsis; white-space:nowrap;}
.nav-lesson-bm{opacity:0; flex-shrink:0;}
.nav-lesson-btn:hover .nav-lesson-bm, .nav-lesson-btn.bookmarked .nav-lesson-bm{opacity:1;}

.exam-sim-btn{
  width:100%; display:flex; align-items:center; gap:10px; padding:11px 12px; border-radius:10px;
  background:linear-gradient(135deg, rgba(5,146,208,0.22), rgba(14,165,160,0.18)); border:1px solid rgba(111,211,199,0.35);
  cursor:pointer; text-align:left;
}
.exam-sim-btn:hover{border-color:var(--code-accent);}
.exam-sim-btn-icon{font-size:20px; flex-shrink:0;}
.exam-sim-btn-title{display:block; font-size:12.8px; font-weight:700; color:#fff;}
.exam-sim-btn-sub{display:block; font-size:10.5px; color:#9FC1D6; margin-top:1px;}

/* ---------- Exam Simulator ---------- */
.exam-config-grid{display:grid; grid-template-columns:repeat(4,1fr); gap:12px; margin-bottom:20px;}
.exam-len-card{border:1.5px solid var(--border); border-radius:12px; padding:16px 12px; text-align:center; cursor:pointer; background:var(--surface);}
.exam-len-card:hover{border-color:var(--cisco-blue);}
.exam-len-card.selected{border-color:var(--cisco-blue); background:rgba(5,146,208,0.06); box-shadow:var(--shadow-sm);}
.exam-len-card .n{font-family:var(--font-display); font-size:22px; font-weight:800; color:var(--navy);}
html.dark .exam-len-card .n{color:#fff;}
.exam-len-card .l{font-size:11px; color:var(--ink-faint); margin-top:2px;}
.exam-len-card .t{font-size:10px; color:var(--ink-faint); margin-top:6px;}
.exam-toggle-row{display:flex; gap:10px; margin-bottom:20px;}
.exam-toggle{flex:1; padding:12px; border-radius:10px; border:1.5px solid var(--border); text-align:center; cursor:pointer; font-size:13px; font-weight:600; color:var(--ink-soft);}
.exam-toggle.selected{border-color:var(--cisco-blue); background:rgba(5,146,208,0.06); color:var(--cisco-blue-dk);}
.exam-domain-chip{padding:8px 14px; border-radius:20px; border:1.5px solid var(--border); font-size:12px; font-weight:600; cursor:pointer; background:var(--surface); color:var(--ink-soft);}
.exam-domain-chip.selected{background:var(--navy); color:#fff; border-color:var(--navy);}
.exam-history-row{display:flex; align-items:center; gap:12px; padding:10px 0; border-bottom:1px solid var(--border-soft); font-size:12.8px;}
.exam-history-row:last-child{border-bottom:none;}
.exam-pass-chip{font-size:10.5px; font-weight:700; padding:3px 9px; border-radius:20px;}
.exam-pass-chip.pass{background:rgba(46,139,87,0.14); color:var(--accent-green);}
.exam-pass-chip.fail{background:rgba(192,57,43,0.12); color:var(--accent-red);}

.exam-topbar{position:sticky; top:0; background:var(--surface); border:1px solid var(--border); border-radius:12px; padding:14px 18px; display:flex; align-items:center; gap:16px; margin-bottom:20px; z-index:10; box-shadow:var(--shadow-sm);}
.exam-timer{font-family:var(--font-mono); font-size:16px; font-weight:700; color:var(--navy); background:var(--bg-soft); padding:6px 14px; border-radius:8px;}
.exam-timer.low{color:var(--accent-red); background:rgba(192,57,43,0.1);}
.exam-progress-text{font-size:12.8px; color:var(--ink-faint); font-weight:600;}
.exam-flag-btn{margin-left:auto;}
.exam-nav-grid{display:grid; grid-template-columns:repeat(10,1fr); gap:6px; margin:18px 0;}
@media (max-width: 760px){ .exam-nav-grid{grid-template-columns:repeat(6,1fr);} .exam-config-grid{grid-template-columns:repeat(2,1fr);} }
.exam-nav-cell{
  aspect-ratio:1; border-radius:6px; border:1.5px solid var(--border); background:var(--surface); cursor:pointer;
  display:flex; align-items:center; justify-content:center; font-size:11px; font-weight:700; color:var(--ink-faint); font-family:var(--font-mono);
}
.exam-nav-cell.answered{background:rgba(5,146,208,0.1); border-color:var(--cisco-blue); color:var(--cisco-blue-dk);}
.exam-nav-cell.flagged{border-color:var(--accent-amber); background:rgba(201,120,30,0.1); color:var(--accent-amber);}
.exam-nav-cell.current{background:var(--navy); border-color:var(--navy); color:#fff;}
.exam-score-circle{
  width:150px; height:150px; border-radius:50%; margin:0 auto 16px; display:flex; flex-direction:column; align-items:center; justify-content:center;
  border:8px solid var(--bg-soft); position:relative;
}
.exam-score-circle b{font-family:var(--font-display); font-size:32px; font-weight:800;}
.exam-score-circle span{font-size:10.5px; color:var(--ink-faint); text-transform:uppercase; letter-spacing:.05em;}
.exam-pass-badge{display:inline-block; padding:6px 18px; border-radius:20px; font-weight:700; font-size:13px; margin-bottom:6px;}
.exam-pass-badge.pass{background:rgba(46,139,87,0.14); color:var(--accent-green);}
.exam-pass-badge.fail{background:rgba(192,57,43,0.12); color:var(--accent-red);}
.exam-domain-bar-row{display:flex; align-items:center; gap:12px; margin-bottom:10px; font-size:12.5px;}
.exam-domain-bar-row .lbl{width:170px; flex-shrink:0; font-weight:600; color:var(--ink);}
.exam-domain-bar-track{flex:1; height:10px; background:var(--bg-soft); border-radius:6px; overflow:hidden;}
.exam-domain-bar-fill{height:100%; border-radius:6px;}
.exam-domain-bar-pct{width:44px; flex-shrink:0; text-align:right; font-family:var(--font-mono); font-weight:700; color:var(--ink-soft);}
.exam-review-item{border:1px solid var(--border); border-radius:12px; padding:16px; margin-bottom:12px;}
.exam-review-item.wrong{border-color:rgba(192,57,43,0.3); background:rgba(192,57,43,0.03);}
.exam-review-item.correct{border-color:rgba(46,139,87,0.25);}
.exam-review-filter{display:flex; gap:8px; margin-bottom:16px;}

.sidebar-foot{
  padding:14px 16px; border-top:1px solid rgba(255,255,255,0.08);
  display:flex; align-items:center; gap:10px;
}
.streak-chip{
  display:flex; align-items:center; gap:6px; background:rgba(255,255,255,0.06);
  padding:6px 10px; border-radius:20px; font-size:11.5px; color:#F3C56B; font-weight:600;
}
.foot-btn{
  background:rgba(255,255,255,0.07); border:none; color:#DCEAF3; width:32px;height:32px;border-radius:8px;
  display:flex;align-items:center;justify-content:center; cursor:pointer; margin-left:auto;
}
.foot-btn:hover{background:rgba(255,255,255,0.14);}

/* ---------- Main ---------- */
.main{flex:1; min-width:0; display:flex; flex-direction:column;}
.topbar{
  position:sticky; top:0; z-index:30;
  background: rgba(246,248,250,0.85); backdrop-filter: blur(10px);
  border-bottom:1px solid var(--border);
  padding:14px 26px; display:flex; align-items:center; gap:16px;
}
html.dark .topbar{background:rgba(11,22,32,0.85);}
.topbar-menu-btn{display:none; background:var(--surface); border:1px solid var(--border); border-radius:8px; width:36px;height:36px; cursor:pointer;}
.topbar-crumb{font-size:13px; color:var(--ink-faint); font-weight:500;}
.topbar-crumb b{color:var(--ink); font-weight:600;}
.topbar-actions{margin-left:auto; display:flex; align-items:center; gap:10px;}
.icon-btn{
  width:38px;height:38px; border-radius:9px; border:1px solid var(--border); background:var(--surface);
  display:flex;align-items:center;justify-content:center; cursor:pointer; color:var(--ink-soft);
  transition:.15s ease;
}
.icon-btn:hover{border-color:var(--cisco-blue); color:var(--cisco-blue); box-shadow:var(--shadow-sm);}
.icon-btn.active{background:var(--cisco-blue); color:#fff; border-color:var(--cisco-blue);}
.xp-pill{
  display:flex; align-items:center; gap:8px; background:var(--surface); border:1px solid var(--border);
  padding:7px 14px; border-radius:20px; font-size:12.5px; font-weight:600; color:var(--ink-soft);
}
.xp-pill b{color:var(--cisco-blue-dk); font-family:var(--font-mono);}

.content{flex:1; padding:28px 34px 80px; max-width:1180px; width:100%; margin:0 auto;}

/* ---------- Buttons ---------- */
.btn{
  display:inline-flex; align-items:center; gap:8px; padding:10px 18px; border-radius:9px;
  font-family:var(--font-body); font-weight:600; font-size:13.5px; cursor:pointer; border:1px solid transparent;
  transition:.15s ease;
}
.btn-primary{background:var(--cisco-blue); color:#fff;}
.btn-primary:hover{background:var(--cisco-blue-dk);}
.btn-outline{background:var(--surface); border-color:var(--border); color:var(--ink);}
.btn-outline:hover{border-color:var(--cisco-blue); color:var(--cisco-blue-dk);}
.btn-ghost{background:transparent; border-color:transparent; color:var(--ink-soft);}
.btn-ghost:hover{background:var(--bg-soft);}
.btn-sm{padding:7px 12px; font-size:12.5px; border-radius:7px;}
.btn:disabled{opacity:.45; cursor:not-allowed;}

/* ---------- Cards ---------- */
.card{
  background:var(--surface); border:1px solid var(--border); border-radius:var(--radius-lg);
  box-shadow: var(--shadow-sm);
}
.card-pad{padding:22px 24px;}

/* ---------- Home / Dashboard ---------- */
.hero{
  background: radial-gradient(1200px 300px at 20% -20%, rgba(5,146,208,0.16), transparent),
              linear-gradient(135deg, var(--navy) 0%, #0E3A54 60%, #0B2C41 100%);
  border-radius: 20px; padding:38px 36px; color:#fff; position:relative; overflow:hidden;
  margin-bottom:26px;
}
.hero::after{
  content:""; position:absolute; right:-40px; top:-40px; width:280px; height:280px; border-radius:50%;
  background: radial-gradient(circle, rgba(111,211,199,0.18), transparent 70%);
}
.hero-eyebrow{font-family:var(--font-mono); font-size:11.5px; letter-spacing:.12em; text-transform:uppercase; color:var(--code-accent); margin-bottom:10px;}
.hero h1{font-size:30px; margin:0 0 10px; font-weight:800; letter-spacing:-.01em;}
.hero p{font-size:14.5px; color:#B9D3E2; max-width:560px; line-height:1.6; margin:0 0 22px;}
.hero-stats{display:flex; gap:28px; flex-wrap:wrap; position:relative;}
.hero-stat b{display:block; font-family:var(--font-display); font-size:24px; font-weight:800;}
.hero-stat span{font-size:11.5px; color:#8FB4CB; text-transform:uppercase; letter-spacing:.06em;}

.stat-grid{display:grid; grid-template-columns:repeat(4,1fr); gap:16px; margin-bottom:26px;}
.stat-card{background:var(--surface); border:1px solid var(--border); border-radius:14px; padding:18px 18px;}
.stat-card .n{font-family:var(--font-display); font-size:22px; font-weight:800; color:var(--navy);}
html.dark .stat-card .n{color:#fff;}
.stat-card .l{font-size:12px; color:var(--ink-faint); margin-top:4px;}
.stat-card .bar{height:5px; background:var(--bg-soft); border-radius:3px; margin-top:12px; overflow:hidden;}
.stat-card .bar i{display:block; height:100%; background:linear-gradient(90deg,var(--cisco-blue),var(--accent-teal));}

.section-title{display:flex; align-items:center; gap:10px; margin:32px 0 16px;}
.section-title h2{font-size:17px; margin:0; font-weight:700;}
.section-title .line{flex:1; height:1px; background:var(--border);}

.module-grid{display:grid; grid-template-columns:repeat(2,1fr); gap:16px;}
.module-card{
  background:var(--surface); border:1px solid var(--border); border-radius:16px; padding:20px 22px;
  cursor:pointer; transition:.15s ease; position:relative; overflow:hidden;
}
.module-card:hover{border-color:var(--cisco-blue); box-shadow:var(--shadow-md); transform:translateY(-2px);}
.module-card .mnum{
  width:34px;height:34px;border-radius:9px; display:flex;align-items:center;justify-content:center;
  font-family:var(--font-mono); font-weight:700; font-size:13px; color:#fff; margin-bottom:12px;
}
.module-card h3{font-size:15px; margin:0 0 6px;}
.module-card p{font-size:12.5px; color:var(--ink-faint); margin:0 0 12px; line-height:1.5;}
.module-card .mmeta{display:flex; justify-content:space-between; align-items:center; font-size:11.5px; color:var(--ink-faint);}
.module-card .bar{height:5px; background:var(--bg-soft); border-radius:3px; margin-top:10px; overflow:hidden;}
.module-card .bar i{display:block; height:100%; background:linear-gradient(90deg,var(--cisco-blue),var(--accent-teal));}

/* ---------- Lesson Page ---------- */
.lesson-head{margin-bottom:22px;}
.lesson-tags{display:flex; gap:8px; margin-bottom:12px; flex-wrap:wrap;}
.tag{font-size:10.5px; font-weight:700; text-transform:uppercase; letter-spacing:.05em; padding:4px 10px; border-radius:20px;}
.tag-module{background:rgba(5,146,208,0.12); color:var(--cisco-blue-dk);}
.tag-flagship{background:rgba(14,165,160,0.14); color:var(--accent-teal);}
.tag-time{background:var(--bg-soft); color:var(--ink-faint);}
.lesson-head h1{font-size:26px; margin:0 0 8px; font-weight:800;}
.lesson-actions{display:flex; gap:10px; margin-top:14px; flex-wrap:wrap;}

.toc-rail{display:flex; gap:6px; overflow-x:auto; padding:4px 0 18px; border-bottom:1px solid var(--border); margin-bottom:26px;}
.toc-chip{
  flex-shrink:0; font-size:12px; font-weight:600; color:var(--ink-soft); background:var(--bg-soft);
  padding:7px 13px; border-radius:20px; cursor:pointer; border:1px solid transparent; white-space:nowrap;
}
.toc-chip:hover{border-color:var(--cisco-blue);}
.toc-chip.active{background:var(--cisco-blue); color:#fff;}

.lesson-block{margin-bottom:30px; scroll-margin-top:90px;}
.lesson-block h2{
  font-size:17px; display:flex; align-items:center; gap:10px; margin:0 0 14px;
}
.lesson-block h2 .bicon{
  width:30px;height:30px; border-radius:8px; display:flex;align-items:center;justify-content:center; color:#fff; flex-shrink:0;
}
.lesson-prose{font-size:14px; line-height:1.75; color:var(--ink-soft);}
.lesson-prose p{margin:0 0 12px;}
.lesson-prose strong{color:var(--ink); font-weight:700;}
.lesson-prose ul{margin:0 0 12px; padding-left:20px;}
.lesson-prose li{margin-bottom:6px;}

.why-grid{display:grid; grid-template-columns:repeat(4,1fr); gap:12px; margin:16px 0;}
.why-box{background:var(--surface-2); border:1px solid var(--border-soft); border-radius:12px; padding:14px;}
.why-box b{display:block; font-size:11px; text-transform:uppercase; letter-spacing:.05em; color:var(--cisco-blue-dk); margin-bottom:6px;}
.why-box span{font-size:12.5px; color:var(--ink-soft); line-height:1.5;}

.obj-list{list-style:none; margin:0; padding:0; display:grid; gap:8px;}
.obj-list li{display:flex; gap:10px; font-size:13.5px; color:var(--ink-soft); align-items:flex-start;}
.obj-list li svg{flex-shrink:0; margin-top:2px; color:var(--accent-green);}

.device-grid{display:flex; flex-wrap:wrap; gap:10px;}
.device-chip{
  display:flex; align-items:center; gap:8px; background:var(--surface-2); border:1px solid var(--border-soft);
  padding:8px 14px; border-radius:10px; font-size:12.5px; font-weight:600; color:var(--ink);
}
.device-chip .cnt{background:var(--cisco-blue); color:#fff; font-family:var(--font-mono); font-size:11px; width:20px;height:20px;border-radius:6px; display:flex;align-items:center;justify-content:center;}

.topo-canvas{
  background: var(--surface-2); border:1px solid var(--border-soft); border-radius:14px; padding:26px;
  overflow-x:auto;
}
.topo-canvas svg{display:block; margin:0 auto;}

.ip-table{width:100%; border-collapse:collapse; font-size:12.5px;}
.ip-table th{
  background:var(--navy); color:#fff; text-align:left; padding:10px 12px; font-size:11px;
  text-transform:uppercase; letter-spacing:.04em; font-weight:600;
}
.ip-table th:first-child{border-top-left-radius:8px;}
.ip-table th:last-child{border-top-right-radius:8px;}
.ip-table td{padding:9px 12px; border-bottom:1px solid var(--border-soft); font-family:var(--font-mono); color:var(--ink-soft);}
.ip-table tr:nth-child(even) td{background:var(--surface-2);}

.steps{counter-reset: step; display:flex; flex-direction:column; gap:0;}
.step{
  display:flex; gap:16px; padding:16px 0; border-bottom:1px dashed var(--border);
  position:relative;
}
.step:last-child{border-bottom:none;}
.step-port{
  counter-increment: step; flex-shrink:0; width:34px;height:34px; border-radius:8px;
  background:var(--navy); color:var(--code-accent); font-family:var(--font-mono); font-weight:700; font-size:13px;
  display:flex;align-items:center;justify-content:center;
}
.step-port::before{content: counter(step, decimal-leading-zero);}
.step-body{flex:1; min-width:0;}
.step-body h4{margin:0 0 6px; font-size:13.5px; font-weight:700;}
.step-body p{margin:0 0 8px; font-size:13px; color:var(--ink-soft); line-height:1.6;}

pre.code{
  background:var(--code-bg); color:var(--code-ink); border-radius:10px; padding:14px 16px;
  font-family:var(--font-mono); font-size:12.8px; line-height:1.7; overflow-x:auto; margin:8px 0;
  position:relative;
}
pre.code .c{color:#7FA8B8; font-style:italic;}
pre.code .kw{color:var(--code-accent); font-weight:600;}
.code-explain{
  font-size:12.5px; color:var(--ink-faint); background:var(--surface-2); border-left:3px solid var(--cisco-blue);
  padding:8px 12px; border-radius:0 8px 8px 0; margin:6px 0 14px;
}
.copy-btn{
  position:absolute; top:8px; right:8px; background:rgba(255,255,255,0.08); border:none; color:#CFE8F5;
  font-size:10.5px; padding:4px 9px; border-radius:6px; cursor:pointer; font-family:var(--font-body);
}
.copy-btn:hover{background:rgba(255,255,255,0.18);}

.callout{border-radius:12px; padding:14px 16px; font-size:13px; line-height:1.6; margin:12px 0; display:flex; gap:12px;}
.callout svg{flex-shrink:0; margin-top:2px;}
.callout-mistake{background:rgba(192,57,43,0.07); border:1px solid rgba(192,57,43,0.25); color:#8B2E22;}
html.dark .callout-mistake{color:#F4A79B;}
.callout-mistake svg{color:var(--accent-red);}
.callout-fix{background:rgba(46,139,87,0.07); border:1px solid rgba(46,139,87,0.25); color:#1E5E3B;}
html.dark .callout-fix{color:#A7E3C1;}
.callout-fix svg{color:var(--accent-green);}
.callout-tip{background:rgba(5,146,208,0.07); border:1px solid rgba(5,146,208,0.25); color:var(--cisco-blue-dk);}
.callout-tip svg{color:var(--cisco-blue);}

.mistake-row{display:grid; grid-template-columns:1fr 1fr; gap:10px; margin-bottom:10px;}
.mistake-card, .fix-card{border-radius:10px; padding:12px 14px; font-size:12.8px; line-height:1.55;}
.mistake-card{background:rgba(192,57,43,0.06); border:1px solid rgba(192,57,43,0.2);}
.fix-card{background:rgba(46,139,87,0.06); border:1px solid rgba(46,139,87,0.2);}
.mistake-card b, .fix-card b{display:block; font-size:10.5px; text-transform:uppercase; letter-spacing:.05em; margin-bottom:4px;}
.mistake-card b{color:var(--accent-red);} .fix-card b{color:var(--accent-green);}

.troubleshoot-scenario{
  background:var(--surface-2); border:1px solid var(--border-soft); border-radius:12px; padding:16px 18px; margin-bottom:14px;
}
.troubleshoot-scenario h4{margin:0 0 8px; font-size:13.5px;}
.reveal-btn{margin-top:10px;}
.reveal-body{display:none; margin-top:12px; padding-top:12px; border-top:1px dashed var(--border);}
.reveal-body.open{display:block;}

.challenge-box{
  background: linear-gradient(135deg, var(--navy), #0E3A54); color:#fff; border-radius:16px; padding:24px 26px;
  position:relative; overflow:hidden;
}
.challenge-box h3{margin:0 0 8px; font-size:16.5px; display:flex; align-items:center; gap:8px;}
.challenge-box p{font-size:13.3px; color:#BBD8E8; line-height:1.65; margin:0 0 14px;}
.challenge-solution{display:none; margin-top:16px; background:rgba(255,255,255,0.07); border-radius:12px; padding:16px;}
.challenge-solution.open{display:block;}

/* ---------- Quiz ---------- */
.quiz-progress{display:flex; gap:5px; margin-bottom:18px;}
.quiz-progress i{flex:1; height:5px; border-radius:3px; background:var(--bg-soft);}
.quiz-progress i.answered{background:var(--cisco-blue);}
.quiz-progress i.correct{background:var(--accent-green);}
.quiz-progress i.wrong{background:var(--accent-red);}
.quiz-card{margin-bottom:16px;}
.quiz-q-type{font-size:10.5px; font-weight:700; text-transform:uppercase; letter-spacing:.05em; color:var(--cisco-blue-dk); margin-bottom:8px;}
.quiz-q-text{font-size:15px; font-weight:600; margin-bottom:16px; line-height:1.5;}
.quiz-options{display:grid; gap:9px;}
.quiz-opt{
  display:flex; gap:12px; align-items:flex-start; padding:12px 14px; border-radius:10px; border:1.5px solid var(--border);
  cursor:pointer; font-size:13.3px; background:var(--surface-2); transition:.12s ease;
}
.quiz-opt:hover{border-color:var(--cisco-blue);}
.quiz-opt .letter{
  width:22px;height:22px; border-radius:6px; background:var(--bg-soft); display:flex;align-items:center;justify-content:center;
  font-size:11px; font-weight:700; flex-shrink:0; font-family:var(--font-mono);
}
.quiz-opt.selected{border-color:var(--cisco-blue); background:rgba(5,146,208,0.06);}
.quiz-opt.correct{border-color:var(--accent-green); background:rgba(46,139,87,0.08);}
.quiz-opt.correct .letter{background:var(--accent-green); color:#fff;}
.quiz-opt.wrong{border-color:var(--accent-red); background:rgba(192,57,43,0.08);}
.quiz-opt.wrong .letter{background:var(--accent-red); color:#fff;}
.quiz-feedback{font-size:12.8px; margin-top:10px; padding:10px 12px; border-radius:8px; background:var(--bg-soft); line-height:1.55;}
.quiz-nav{display:flex; justify-content:space-between; margin-top:18px;}
.quiz-result{text-align:center; padding:30px 20px;}
.quiz-result .score{font-family:var(--font-display); font-size:44px; font-weight:800; color:var(--cisco-blue-dk);}

/* ---------- Tools ---------- */
.tool-tabs{display:flex; gap:8px; margin-bottom:22px; flex-wrap:wrap;}
.tool-tab{padding:9px 16px; border-radius:9px; background:var(--surface); border:1px solid var(--border); font-size:13px; font-weight:600; cursor:pointer; color:var(--ink-soft);}
.tool-tab.active{background:var(--navy); color:#fff; border-color:var(--navy);}
.tool-grid{display:grid; grid-template-columns:1fr 1fr; gap:20px;}
.field-row{margin-bottom:14px;}
.field-row label{display:block; font-size:12px; font-weight:600; color:var(--ink-soft); margin-bottom:6px;}
.field-row input, .field-row select{
  width:100%; padding:10px 12px; border-radius:8px; border:1.5px solid var(--border); font-family:var(--font-mono);
  font-size:13.5px; background:var(--surface); color:var(--ink);
}
.field-row input:focus, .field-row select:focus{outline:none; border-color:var(--cisco-blue);}
.result-panel{background:var(--code-bg); color:var(--code-ink); border-radius:12px; padding:16px 18px; font-family:var(--font-mono); font-size:12.8px; line-height:1.9;}
.result-panel .rk{color:#7FA8B8;}
.result-row{display:flex; justify-content:space-between; padding:4px 0; border-bottom:1px dashed rgba(255,255,255,0.08);}
.result-row:last-child{border-bottom:none;}

.flash-card-wrap{perspective:1200px; max-width:520px; margin:0 auto;}
.flash-card{
  height:260px; border-radius:18px; position:relative; cursor:pointer; transform-style:preserve-3d; transition:transform .5s;
}
.flash-card.flipped{transform:rotateY(180deg);}
.flash-face{
  position:absolute; inset:0; backface-visibility:hidden; border-radius:18px; display:flex; flex-direction:column;
  align-items:center; justify-content:center; padding:30px; text-align:center;
}
.flash-front{background:linear-gradient(135deg,var(--navy),#0E3A54); color:#fff;}
.flash-back{background:var(--surface); border:2px solid var(--cisco-blue); transform:rotateY(180deg); color:var(--ink);}
.flash-face b{font-size:11px; text-transform:uppercase; letter-spacing:.08em; opacity:.6; margin-bottom:14px;}
.flash-face p{font-size:16px; line-height:1.5; font-weight:600; margin:0;}

.cli-sim{background:var(--code-bg); border-radius:14px; padding:18px 20px; font-family:var(--font-mono); font-size:13px; color:var(--code-ink); min-height:340px; display:flex; flex-direction:column;}
.cli-output{flex:1; overflow-y:auto; max-height:340px; white-space:pre-wrap; line-height:1.6;}
.cli-input-row{display:flex; align-items:center; gap:8px; margin-top:10px; border-top:1px solid rgba(255,255,255,0.1); padding-top:10px;}
.cli-input-row input{flex:1; background:transparent; border:none; color:var(--code-accent); font-family:var(--font-mono); font-size:13px;}
.cli-input-row input:focus{outline:none;}
.cli-prompt{color:var(--code-accent); font-weight:700;}

/* ---------- Projects ---------- */
.project-card{border:1px solid var(--border); border-radius:16px; overflow:hidden; margin-bottom:20px;}
.project-head{padding:20px 24px; display:flex; align-items:center; gap:16px; cursor:pointer;}
.project-badge{
  width:44px;height:44px;border-radius:12px; display:flex;align-items:center;justify-content:center; color:#fff;
  font-family:var(--font-display); font-weight:800; flex-shrink:0;
}
.project-body{padding:0 24px 24px; display:none;}
.project-body.open{display:block;}
.diff-badge{font-size:10.5px; font-weight:700; text-transform:uppercase; padding:3px 10px; border-radius:20px;}
.diff-beginner{background:rgba(46,139,87,0.12); color:var(--accent-green);}
.diff-intermediate{background:rgba(201,120,30,0.14); color:var(--accent-amber);}
.diff-advanced{background:rgba(192,57,43,0.12); color:var(--accent-red);}
.check-grid{display:grid; grid-template-columns:1fr 1fr; gap:6px 20px;}
.check-grid div{display:flex; gap:8px; font-size:12.8px; color:var(--ink-soft); align-items:center;}

/* ---------- Modals ---------- */
.modal-overlay{
  position:fixed; inset:0; background:rgba(10,20,30,0.55); backdrop-filter:blur(3px); z-index:100;
  display:none; align-items:center; justify-content:center; padding:20px;
}
.modal-overlay.open{display:flex;}
.modal-box{
  background:var(--surface); border-radius:18px; max-width:480px; width:100%; padding:26px 26px 22px;
  box-shadow:var(--shadow-lg); max-height:86vh; overflow-y:auto;
}
.modal-box.wide{max-width:640px;}
.modal-box h3{margin:0 0 6px; font-size:17px;}
.modal-close{float:right; cursor:pointer; color:var(--ink-faint);}

.notes-textarea{width:100%; min-height:160px; border-radius:10px; border:1.5px solid var(--border); padding:12px; font-family:var(--font-body); font-size:13.5px; resize:vertical;}

.achv-grid{display:grid; grid-template-columns:repeat(3,1fr); gap:12px;}
.achv-card{border:1px solid var(--border); border-radius:12px; padding:14px 10px; text-align:center; opacity:.35;}
.achv-card.unlocked{opacity:1; border-color:rgba(5,146,208,0.35); background:rgba(5,146,208,0.05);}
.achv-card .ic{font-size:26px; margin-bottom:6px;}
.achv-card b{display:block; font-size:11.5px; margin-bottom:3px;}
.achv-card span{font-size:10px; color:var(--ink-faint); line-height:1.3; display:block;}

.toast{
  position:fixed; bottom:24px; right:24px; background:var(--navy); color:#fff; padding:14px 20px; border-radius:12px;
  box-shadow:var(--shadow-lg); z-index:200; display:flex; align-items:center; gap:12px; font-size:13.3px; font-weight:600;
  transform:translateY(120%); transition:transform .3s ease;
}
.toast.show{transform:translateY(0);}

.cert-canvas{
  background:linear-gradient(135deg,#0E3A54,var(--navy)); border-radius:16px; padding:40px 30px; text-align:center; color:#fff;
  border:6px solid var(--cisco-blue);
}

/* Search results overlay */
.search-results{position:absolute; top:100%; left:16px; right:16px; background:var(--surface); border:1px solid var(--border); border-radius:10px; margin-top:6px; box-shadow:var(--shadow-lg); max-height:340px; overflow-y:auto; z-index:60; display:none;}
.search-results.open{display:block;}
.search-result-item{padding:10px 14px; font-size:12.5px; cursor:pointer; border-bottom:1px solid var(--border-soft); color:var(--ink);}
.search-result-item:hover{background:var(--bg-soft);}
.search-result-item small{display:block; color:var(--ink-faint); margin-top:2px;}

@media (max-width: 980px){
  .module-grid{grid-template-columns:1fr;}
  .tool-grid{grid-template-columns:1fr;}
  .why-grid{grid-template-columns:repeat(2,1fr);}
  .stat-grid{grid-template-columns:repeat(2,1fr);}
  .mistake-row{grid-template-columns:1fr;}
  .achv-grid{grid-template-columns:repeat(2,1fr);}
}
@media (max-width: 760px){
  .sidebar{position:fixed; left:0; height:100vh; transform:translateX(-100%);}
  .sidebar.open{transform:translateX(0);}
  .topbar-menu-btn{display:flex; align-items:center; justify-content:center;}
  .content{padding:20px 16px 70px;}
  .exam-topbar{flex-wrap:wrap; gap:10px;}
  .exam-flag-btn{margin-left:0; order:5; width:100%;}
  .exam-domain-bar-row .lbl{width:110px; font-size:11.5px;}
}

/* JS-driven fallback: identical rules, applied via measured screen width
   in case the browser doesn't evaluate the @media query as expected
   (seen on some Android "open local file" flows). Belt and suspenders. */
html.force-mobile .sidebar{position:fixed !important; left:0; height:100vh; width:300px; transform:translateX(-100%);}
html.force-mobile .sidebar.open{transform:translateX(0);}
html.force-mobile .topbar-menu-btn{display:flex !important; align-items:center; justify-content:center;}
html.force-mobile .content{padding:20px 16px 70px;}
html.force-mobile .main{min-width:0; width:100%;}
html.force-mobile #app{overflow-x:hidden;}
html.force-mobile .exam-topbar{flex-wrap:wrap; gap:10px;}
html.force-mobile .exam-flag-btn{margin-left:0; order:5; width:100%;}
html.force-mobile .exam-domain-bar-row .lbl{width:110px; font-size:11.5px;}

@media print{
  .sidebar, .topbar, .modal-close, #achvModal, #notesModal, .btn{display:none !important;}
  .modal-overlay{position:static !important; background:none !important; backdrop-filter:none !important; display:block !important;}
  .modal-box{box-shadow:none !important; max-width:100% !important;}
  body, .content{padding:0 !important; margin:0 !important;}
  .cert-canvas{border-width:3px;}
}