/* ═════════ ELCB — Dual Theme, 10px radius, Bangla-first ═════════ */
:root{
  --radius:10px;
  --font-bn:'Hind Siliguri','Inter',system-ui,sans-serif;
  --font-head:'Baloo Da 2','Hind Siliguri',sans-serif;
  --font-mono:'JetBrains Mono',monospace;
}
html[data-theme="light"]{
  --bg:#e9eef5; --bg2:#f6f8fb; --card:#ffffff; --border:#d9e1ec;
  --text:#0f172a; --muted:#5b6b84; --sidebar:#ffffff;
  --primary:#0284c7; --primary2:#4f46e5; --console:#0f172a; --console-text:#e2e8f0;
  --code-bg:#eef3f9; --topbar:#ffffff; --shadow:0 4px 18px rgba(15,23,42,.08);
}
html[data-theme="dark"]{
  --bg:#0b1220; --bg2:#0f172a; --card:#111c33; --border:#22314f;
  --text:#e8eefb; --muted:#93a3c4; --sidebar:#0d1528;
  --primary:#38bdf8; --primary2:#818cf8; --console:#060b16; --console-text:#c8f7c5;
  --code-bg:#0a1122; --topbar:#0f1a30; --shadow:0 6px 24px rgba(0,0,0,.45);
}
*{font-family:var(--font-bn)!important}
body{background:var(--bg);color:var(--text);min-height:100vh;transition:background .25s,color .25s}
code,pre,.monaco-editor,.monaco-editor *{font-family:var(--font-mono)!important}

/* Cards / panels — EXACT 10px */
.elcb-card,.card,.modal-content,.alert,.howto,.class-row,.proj-card,.lesson-pane,.editor-pane,.output-console,.code-block,.stat-card,.side-progress{
  border-radius:10px!important;border:1px solid var(--border)!important;
}
.elcb-card{background:var(--card);box-shadow:var(--shadow)}
.text-gradient{background:linear-gradient(90deg,var(--primary),var(--primary2));-webkit-background-clip:text;background-clip:text;color:transparent;font-weight:800}

/* Buttons — small, polished, hover */
.btn-sm{border-radius:10px!important;font-weight:600;font-size:12.5px!important;padding:6px 12px!important;transition:transform .15s,box-shadow .15s,filter .15s}
.btn-primary{background:linear-gradient(135deg,#0ea5e9,#6366f1);border:none}
.btn-primary:hover{transform:translateY(-1px);box-shadow:0 6px 16px rgba(14,165,233,.4);filter:brightness(1.06)}
.btn-success{background:linear-gradient(135deg,#16a34a,#059669);border:none}
.btn-success:hover{transform:translateY(-1px);box-shadow:0 6px 16px rgba(22,163,74,.4)}
.elcb-btn-secondary{background:transparent;border:1px solid var(--border)!important;color:var(--text)}
.elcb-btn-secondary:hover{border-color:var(--primary)!important;color:var(--primary);transform:translateY(-1px)}
.elcb-btn-danger{background:transparent;border:1px solid #f87171!important;color:#f87171}
.elcb-btn-danger:hover{background:#ef4444;color:#fff;transform:translateY(-1px)}
.form-control,.form-select{background:var(--bg2)!important;color:var(--text)!important;border:1px solid var(--border)!important;border-radius:10px!important}
.form-control:focus{border-color:var(--primary)!important;box-shadow:0 0 0 3px rgba(14,165,233,.2)}
.modal-content{background:var(--card)!important;color:var(--text)}
.modal-header,.modal-footer{border-color:var(--border)!important}
.btn-close{filter:invert(.6)}
html[data-theme="light"] .btn-close{filter:none}

/* Layout */
#sidebar{position:fixed;inset:0 auto 0 0;width:258px;background:var(--sidebar);border-right:1px solid var(--border);z-index:1040;display:flex;flex-direction:column;padding:14px;transition:transform .25s}
#mainWrap{margin-left:258px;padding:14px 16px;max-width:1280px}
#topbar{position:sticky;top:12px;z-index:900;display:flex;justify-content:space-between;align-items:center;gap:8px;padding:10px 14px;background:var(--topbar);margin-bottom:14px}
.brand{display:flex;gap:10px;align-items:center;margin-bottom:12px}
.brand-logo,.auth-logo{width:44px;height:44px;min-width:44px;border-radius:10px;background:linear-gradient(135deg,#0ea5e9,#6366f1);display:flex;align-items:center;justify-content:center;color:#fff;font-family:var(--font-mono)!important;font-weight:800;font-size:15px;box-shadow:0 4px 14px rgba(14,165,233,.4)}
.auth-logo{width:60px;height:60px;font-size:20px}
.brand-name{font-weight:800;font-size:14.5px;line-height:1.1}
.brand-name span{background:linear-gradient(90deg,#38bdf8,#818cf8);-webkit-background-clip:text;background-clip:text;color:transparent}
.brand-sub{font-size:11px;color:var(--muted)}
.side-nav{display:flex;flex-direction:column;gap:6px}
.nav-item{display:flex;align-items:center;gap:10px;padding:9px 11px;border-radius:10px;border:1px solid transparent;background:transparent;color:var(--text);font-size:13.5px;font-weight:600;text-align:left;width:100%;transition:.15s}
.nav-item i{font-size:16px;color:var(--primary)}
.nav-item .bn{margin-left:auto;font-size:10.5px;color:var(--muted);font-weight:500}
.nav-item:hover{background:var(--bg2);border-color:var(--border);transform:translateX(2px)}
.nav-item.active{background:linear-gradient(135deg,rgba(14,165,233,.18),rgba(99,102,241,.18));border-color:var(--primary);color:var(--text)}
.side-progress{padding:10px;margin-top:auto;margin-bottom:8px;background:var(--bg2)}
.side-foot{font-size:10.5px;color:var(--muted);text-align:center}
.progress{border-radius:10px;background:var(--bg)}
.progress-bar{background:linear-gradient(90deg,#0ea5e9,#6366f1);border-radius:10px}
.xp-pill,.streak-pill{display:inline-flex;align-items:center;gap:5px;font-size:12px;font-weight:700;padding:4px 11px;border-radius:10px;border:1px solid var(--border);background:var(--bg2)}
.xp-pill{color:#f59e0b}.streak-pill{color:#ef4444}
.view{display:none}.view.active{display:block;animation:fadeUp .25s ease}
@keyframes fadeUp{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}

/* Hero / stats */
.hero-card{background:linear-gradient(135deg,rgba(14,165,233,.12),rgba(99,102,241,.12)),var(--card)!important;overflow:hidden}
.hero-badge{font-size:11px;font-weight:700;background:var(--bg2);border:1px solid var(--border);padding:5px 10px;border-radius:10px;color:var(--primary)}
.hero-code{font-family:var(--font-mono)!important;background:var(--console);color:#7dd3fc;border-radius:10px;padding:18px;font-size:14px;text-align:left;border:1px solid var(--border);box-shadow:var(--shadow)}
.stat-card{padding:14px;text-align:center}
.howto{background:var(--bg2);border:1px solid var(--border);padding:14px;display:flex;flex-direction:column;gap:4px;align-items:center}
.howto i{font-size:22px;color:var(--primary)}
.howto b{font-size:13px}.howto small{color:var(--muted)}

/* Path */
.part-head{background:linear-gradient(135deg,rgba(14,165,233,.14),rgba(99,102,241,.14)),var(--card);padding:12px 14px;display:flex;gap:12px;align-items:center}
.part-num{width:42px;height:42px;min-width:42px;border-radius:10px;background:linear-gradient(135deg,#0ea5e9,#6366f1);color:#fff;font-weight:800;display:flex;align-items:center;justify-content:center}
.class-row{display:flex;align-items:center;gap:10px;padding:10px 12px;background:var(--bg2);margin:8px;transition:.15s}
.class-row:not(.locked):hover{border-color:var(--primary)!important;transform:translateX(3px);cursor:pointer}
.class-row.locked{opacity:.6;cursor:not-allowed}
.class-row.done{border-color:#22c55e!important}
.cls-ico{width:34px;height:34px;min-width:34px;border-radius:10px;display:flex;align-items:center;justify-content:center;background:var(--card);border:1px solid var(--border);font-size:15px}
.done-badge{font-size:10.5px;font-weight:700;background:#16a34a;color:#fff;padding:3px 9px;border-radius:10px}
.lock-badge{font-size:10.5px;font-weight:700;background:var(--card);border:1px solid var(--border);color:var(--muted);padding:3px 9px;border-radius:10px}

/* Lesson + editor */
.lesson-pane,.editor-pane{overflow:hidden}
.lesson-tabs{display:flex;border-bottom:1px solid var(--border);background:var(--bg2)}
.lesson-tab{flex:1;border:none;background:transparent;color:var(--muted);font-size:12.5px;font-weight:700;padding:11px 6px;border-bottom:2px solid transparent}
.lesson-tab.active{color:var(--primary);border-bottom-color:var(--primary);background:rgba(14,165,233,.06)}
.lesson-body{padding:18px 20px;max-height:560px;overflow-y:auto;line-height:2.05;font-size:16.5px}
.lesson-body h5{font-family:var(--font-head)!important;font-weight:700;margin-top:18px;font-size:20px;color:var(--primary);letter-spacing:.2px}
.lesson-body p,.lesson-body li{font-size:16.5px;line-height:2.05}
.lesson-body ul{padding-left:22px}
.lesson-body b,.lesson-body strong{font-weight:700}
.code-block{background:var(--code-bg);border:1px solid var(--border);border-radius:10px;padding:12px;font-family:var(--font-mono)!important;font-size:12.8px;overflow-x:auto;white-space:pre;color:var(--text)}
html[data-theme="dark"] .code-block{color:#bae6fd}
.line-row{background:var(--bg2);border:1px solid var(--border);border-radius:10px;padding:9px 12px;margin-bottom:8px;font-size:14.5px;line-height:1.9}
.line-row code{font-family:var(--font-mono)!important;background:var(--code-bg);padding:2px 7px;border-radius:6px;border:1px solid var(--border);font-size:12px;display:inline-block;margin-bottom:4px}
.quiz-dot{width:8px;height:8px;border-radius:50%;background:#ef4444;display:inline-block;animation:blink 1s infinite}
@keyframes blink{50%{opacity:.2}}
.quiz-q{background:var(--bg2);border:1px solid var(--border);border-radius:10px;padding:12px;margin-bottom:10px;font-size:15px;line-height:1.9}
.quiz-opt{font-size:14.5px}
.quiz-opt{display:block;width:100%;text-align:left;margin:6px 0;padding:8px 10px;border-radius:10px;border:1px solid var(--border);background:var(--card);color:var(--text);font-size:13.5px;transition:.15s}
.quiz-opt:hover:not(:disabled){border-color:var(--primary)}
.quiz-opt.correct{background:rgba(22,163,74,.15)!important;border-color:#22c55e!important}
.quiz-opt.wrong{background:rgba(239,68,68,.15)!important;border-color:#ef4444!important}
.editor-toolbar{display:flex;justify-content:space-between;align-items:center;padding:8px 10px;background:var(--bg2);border-bottom:1px solid var(--border)}
.dot{width:11px;height:11px;border-radius:50%;display:inline-block}.dot.r{background:#f87171}.dot.y{background:#fbbf24}.dot.g{background:#34d399}
.editor-file{font-family:var(--font-mono)!important;font-size:12px;color:var(--muted);margin-left:8px}
#monacoEditor{height:340px}
#pgEditor{height:380px}
.output-head{display:flex;justify-content:space-between;align-items:center;padding:8px 10px;font-size:12.5px;font-weight:700;background:var(--bg2);border-top:1px solid var(--border);border-bottom:1px solid var(--border)}
.output-console{background:var(--console);color:#f8fafc!important;font-family:var(--font-mono)!important;font-size:14px;font-weight:500;padding:12px;min-height:120px;max-height:220px;overflow-y:auto;white-space:pre-wrap;border-radius:0 0 10px 10px!important;border:none!important;text-shadow:0 1px 2px rgba(0,0,0,.5)}
.output-console .text-muted{color:#9fb0c7!important}
.out-ok{color:#86efac!important;font-weight:700}.out-err{color:#fca5a5!important;font-weight:700}.out-info{color:#8fd6ff!important;font-weight:600}
/* output view tabs (Terminal / Preview) */
.out-tabs{display:flex;gap:4px}
.out-tab{background:transparent;border:1px solid #2b3a58;color:#9fb0c7;font-size:11.5px;font-weight:700;border-radius:8px;padding:3px 10px;transition:.15s}
.out-tab:hover{color:#fff;border-color:var(--primary)}
.out-tab.active{background:linear-gradient(135deg,#0ea5e9,#6366f1);color:#fff;border-color:transparent}
.output-preview{width:100%;height:180px;background:#fff;border:none;border-radius:0 0 10px 10px;display:block}

/* Playground tabs */
.pg-tabs{display:flex;gap:6px;flex-wrap:wrap}
.pg-tab{border:1px solid var(--border);background:var(--card);color:var(--text);font-size:12.5px;font-weight:700;padding:6px 13px;border-radius:10px}
.pg-tab.active{background:linear-gradient(135deg,#0ea5e9,#6366f1);color:#fff;border-color:transparent}

/* Projects */
.proj-card{padding:16px;display:flex;flex-direction:column;gap:8px;height:100%}
.proj-ico{width:40px;height:40px;border-radius:10px;display:flex;align-items:center;justify-content:center;font-size:18px;color:#fff}
.crumb-part{font-size:11px;color:var(--primary);font-weight:700}
.avatar-circle{width:74px;height:74px;border-radius:10px;background:linear-gradient(135deg,#0ea5e9,#6366f1);color:#fff;font-size:30px;font-weight:800;display:flex;align-items:center;justify-content:center}
.achieve{font-size:12px;font-weight:700;padding:7px 12px;border-radius:10px;border:1px solid var(--border);background:var(--bg2);color:var(--muted)}
.achieve.won{background:linear-gradient(135deg,rgba(245,158,11,.2),rgba(239,68,68,.15));border-color:#f59e0b;color:var(--text)}
#confettiCanvas{position:fixed;inset:0;pointer-events:none;z-index:2000}
#sidebarToggle{position:fixed;top:12px;left:12px;z-index:1050}
/* ═══ Focus mode — TRUE fullscreen: edge-to-edge, zero gap ═══
   editor বামে + lesson ডানে + terminal editor-এর নিচে, মনিটর জুড়ে */
body.focus-mode{overflow:hidden}
body.focus-mode #sidebar,body.focus-mode #sidebarToggle{display:none!important}
body.focus-mode #topbar{display:none!important}
body.focus-mode #mainWrap{margin:0!important;max-width:none!important;padding:0!important}
body.focus-mode #mainWrap>footer{display:none!important}
body.focus-mode #view-class{display:flex;flex-direction:column;height:100vh;height:100dvh}
body.focus-mode #classRoom{display:flex;flex-direction:column;flex:1 1 auto;min-height:0}
body.focus-mode #classRoom>.elcb-card{margin:0!important;border-radius:0!important;border-left:none!important;border-right:none!important;flex:0 0 auto}
body.focus-mode #classRow{flex:1 1 auto;min-height:0;height:auto!important;margin:0!important}
body.focus-mode #classRow .classroom-col{min-height:0}
body.focus-mode #monacoEditor{height:42vh!important;flex:0 0 auto}
body.focus-mode #monacoEditor textarea{height:42vh!important}
body.focus-mode .lesson-body{max-height:none}
/* lesson কোণায় focus-off বাটন (শুধু focus mode-এ দেখা যাবে) */
.lesson-pane{position:relative}
#focusOffFab{display:none;position:absolute;top:6px;right:6px;z-index:30;width:30px;height:30px;border-radius:8px;border:1px solid var(--border);background:var(--bg2);color:var(--text);font-size:14px;line-height:1;cursor:pointer}
#focusOffFab:hover{color:var(--primary);border-color:var(--primary)}
body.focus-mode #focusOffFab{display:block}
@media(max-width:991px){
  body.focus-mode #view-class{display:block;height:100vh;height:100dvh;overflow-y:auto}
  body.focus-mode #classRow{height:auto}
  body.focus-mode #monacoEditor,body.focus-mode #monacoEditor textarea{height:300px!important}
}
/* kbd hint inside buttons */
kbd{font-family:var(--font-mono)!important;font-size:10px;background:rgba(255,255,255,.22);border:1px solid rgba(255,255,255,.35);border-radius:6px;padding:1px 6px;margin-left:4px}
.elcb-btn-secondary kbd{background:var(--code-bg);border-color:var(--border)}
/* editor loading placeholder (never blank) */
.editor-loading{min-height:340px;display:flex;align-items:center;justify-content:center;gap:10px;color:var(--muted);font-size:13px;background:var(--console)}
/* tasks checklist */
.task-item{display:flex;gap:8px;align-items:flex-start;background:var(--bg2);border:1px solid var(--border);border-radius:10px;padding:8px 10px;margin-bottom:6px;font-size:14.5px;line-height:1.8;transition:.15s}
#taskCard h6{font-family:var(--font-head)!important;font-size:17px}
.task-item code{font-family:var(--font-mono)!important;background:var(--code-bg);border:1px solid var(--border);border-radius:6px;padding:0 6px;font-size:11.5px}
.task-item.task-done{border-color:#22c55e;background:rgba(22,163,74,.07)}
#goNextClassBtn{animation:glowPulse 1.6s infinite}
@keyframes glowPulse{0%,100%{box-shadow:0 0 0 0 rgba(14,165,233,.5)}50%{box-shadow:0 0 0 7px rgba(14,165,233,0)}}
/* ═══ Movable + resizable classroom ═══ */
.drag-grip{cursor:grab;color:var(--muted);padding:2px 4px;border-radius:6px;font-size:15px;touch-action:none}
.drag-grip:hover{color:var(--primary);background:rgba(14,165,233,.1)}
.drag-grip:active{cursor:grabbing}
.lesson-collapse{flex:0 0 auto!important;padding:11px 10px!important}
#splitDrag{flex:0 0 auto;width:14px;cursor:col-resize;border-radius:10px;background:var(--bg2);border:1px solid var(--border);display:none;align-items:center;justify-content:center;color:var(--muted);font-size:11px;user-select:none;touch-action:none;min-height:120px}
#splitDrag span{writing-mode:vertical-rl;letter-spacing:1px}
#splitDrag:hover,#splitDrag.dragging{background:rgba(14,165,233,.25);border-color:var(--primary);color:var(--primary)}
#edOutDrag{height:16px;cursor:row-resize;background:var(--bg2);border-top:1px solid var(--border);border-bottom:1px solid var(--border);display:flex;align-items:center;justify-content:center;user-select:none;touch-action:none}
#edOutDrag span{width:64px;height:5px;border-radius:4px;background:var(--border)}
/* ═══ Editor tools: toggle on-state + error line লাল ═══ */
.tool-on{border-color:var(--primary)!important;color:var(--primary)!important}
.errLine{background:rgba(239,68,68,.30)!important}
html[data-theme="light"] .errLine{background:rgba(239,68,68,.22)!important}
/* ═══ Track selector cards ═══ */
.track-card{display:flex;align-items:center;gap:10px;padding:10px 12px;border-radius:10px;border:1px solid var(--border);background:var(--bg2);cursor:pointer;transition:.15s;height:100%}
.track-card:hover{border-color:var(--primary);transform:translateY(-2px)}
.track-card.active{border-color:var(--primary);box-shadow:0 0 0 2px rgba(14,165,233,.35);background:linear-gradient(135deg,rgba(14,165,233,.12),rgba(99,102,241,.12))}
.track-ico{width:38px;height:38px;min-width:38px;border-radius:10px;display:flex;align-items:center;justify-content:center;font-size:18px;color:#fff}
#edOutDrag:hover span,#edOutDrag.dragging span{background:var(--primary)}
.classroom-col.drop-hint{outline:2px dashed var(--primary)!important;outline-offset:3px}
.fab-restore{position:fixed;bottom:18px;z-index:1200;box-shadow:0 8px 22px rgba(14,165,233,.4)}
#showEditorFab{left:16px}
#showLessonFab{left:160px}
/* terminal look */
.term-head{background:#0a0f1e!important;color:#cbd5e1;border-top:1px solid var(--border);border-bottom:1px solid #1e293b}
html[data-theme="light"] .term-head{background:#0d1528!important}
.output-console{position:relative}
.output-console::after{content:"▊";color:#4ade80;animation:blink 1.1s infinite;margin-left:2px}
@media(min-width:992px){
  #classRow{flex-wrap:nowrap!important}
  #classRow .classroom-col{flex:1 1 0;min-width:0;max-width:none}
  #splitDrag{display:flex}
}
@media(max-width:991px){
  #splitDrag{display:none!important}
  .lesson-body{font-size:16px}
}
/* ═══ Independent pane scrolling (desktop): page stays fixed, each pane scrolls alone ═══ */
@media(min-width:992px){
  #classRow{flex-wrap:nowrap!important;height:calc(100vh - 218px);min-height:500px}
  body.focus-mode #classRow{height:calc(100vh - 112px)}
  #classRow .classroom-col{flex:1 1 0;min-width:0;max-width:none;display:flex;flex-direction:column;min-height:0}
  #editorCol .editor-pane{flex:1 1 auto;display:flex;flex-direction:column;min-height:0}
  #monacoEditor{flex:0 0 auto}
  #edOutDrag{flex:0 0 auto}
  #outputWrap{flex:1 1 auto;display:flex;flex-direction:column;min-height:0}
  #outputWrap .term-head{flex:0 0 auto}
  #codeOutput{flex:1 1 auto;min-height:90px;max-height:none!important;overscroll-behavior:contain}
  #codePreview{flex:1 1 auto;min-height:120px;height:auto}
  #lessonCol .lesson-pane{flex:1 1 auto;display:flex;flex-direction:column;min-height:0;margin-bottom:0}
  .lesson-body{flex:1 1 auto;max-height:none!important;min-height:0;overscroll-behavior:contain}
  #taskCard{flex:0 0 auto;max-height:232px;overflow-y:auto;overscroll-behavior:contain}
}
html[data-theme="light"] #sidebar{box-shadow:2px 0 14px rgba(15,23,42,.06)}
/* page zoom via body{zoom} — JS applyZoom() সেট করে (80%–130%) */
/* compact-class: classroom FULL size থাকে, শুধু ভেতরের বাটন ছোট হয় (editor-এর জায়গা বাঁচে) */
body.compact-class #view-class .btn-sm{font-size:11px!important;padding:4px 9px!important}
body.compact-class #view-class .lesson-tab{font-size:11.5px!important;padding:9px 5px!important}
body.compact-class #view-class .out-tab{font-size:10.5px!important;padding:2px 8px!important}
body.compact-class #view-class .task-item{font-size:12.5px!important;padding:6px 8px!important}
body.compact-class #view-class .quiz-opt{font-size:12.5px!important;padding:6px 8px!important}
body.compact-class #view-class .editor-file{font-size:11px!important}
body.compact-class #view-class .xp-pill,body.compact-class #view-class .streak-pill{font-size:11px!important;padding:3px 9px!important}
body.compact-class #view-class kbd{display:none}
/* brand logo image */
.brand-logo-img{width:44px;height:44px;border-radius:10px;box-shadow:0 4px 14px rgba(14,165,233,.4)}
/* terminal clear button always visible */
.term-head .elcb-btn-secondary{background:#1e293b!important;color:#e2e8f0!important;border-color:#334155!important}
.term-head .elcb-btn-secondary:hover{background:#334155!important;color:#fff!important}
/* editor toolbar buttons fixed size (never grow) */
.editor-toolbar .btn-sm{font-size:12px!important;padding:5px 9px!important;flex:0 0 auto}
.editor-toolbar{gap:4px}
/* bottom spacing fix */
#mainWrap{padding-bottom:0}
#mainWrap>footer{margin-top:8px;padding:10px 0!important}
html[data-theme="light"] #mainWrap>footer{border-top:1px solid var(--border)}
html[data-theme="light"] .nav-item.active{background:linear-gradient(135deg,rgba(2,132,199,.12),rgba(79,70,229,.12))}
html[data-theme="light"] .lesson-tab.active{background:rgba(2,132,199,.08)}
html[data-theme="light"] .class-row{background:#fff}
html[data-theme="light"] .quiz-opt{background:#fff}
html[data-theme="light"] .quiz-opt:hover:not(:disabled){box-shadow:0 2px 10px rgba(2,132,199,.15)}
html[data-theme="light"] .hero-card{border-color:#bae6fd!important}
html[data-theme="light"] .code-block{background:#eef3f9}
html[data-theme="light"] .line-row{background:#fff}
html[data-theme="light"] .xp-pill,html[data-theme="light"] .streak-pill{background:#fff}
html[data-theme="light"] .part-head{background:linear-gradient(135deg,rgba(2,132,199,.1),rgba(79,70,229,.1)),#fff}
html[data-theme="light"] .howto{background:#fff}
html[data-theme="light"] .task-item{background:#fff}
html[data-theme="light"] .achieve{background:#fff}
html[data-theme="light"] .pg-tab{background:#fff}
html[data-theme="light"] .editor-file{color:#475569}
.toast{background:var(--card)!important;color:var(--text);border-radius:10px!important}
::-webkit-scrollbar{width:9px;height:9px}::-webkit-scrollbar-thumb{background:var(--border);border-radius:10px}::-webkit-scrollbar-thumb:hover{background:var(--primary)}

@media(max-width:991px){
  #sidebar{transform:translateX(-110%)}
  #sidebar.open{transform:none;box-shadow:0 0 60px rgba(0,0,0,.5)}
  #mainWrap{margin-left:0;padding-top:56px}
  .lesson-body{max-height:none}
}

/* ═══ Landing page (logo = big background + white/brand overlay) ═══ */
#landingPage{min-height:100vh;background:var(--bg)}
.land-nav{position:sticky;top:0;z-index:100;display:flex;justify-content:space-between;align-items:center;gap:8px;padding:10px 18px;background:var(--topbar);border-bottom:1px solid var(--border)}
.land-hero{position:relative;overflow:hidden;background:#0b1220;min-height:84vh;display:flex;align-items:center}
.land-hero-bg{position:absolute;inset:0;background:url('assets/logo.png') center/contain no-repeat}
.land-hero-veil{position:absolute;inset:0;background:linear-gradient(115deg,rgba(255,255,255,.97) 0%,rgba(224,242,254,.94) 38%,rgba(14,165,233,.72) 72%,rgba(99,102,241,.86) 100%)}
.land-hero-inner{position:relative;z-index:2;width:100%;max-width:1100px;margin:0 auto;padding:56px 22px;display:grid;grid-template-columns:1.05fr .95fr;gap:28px;align-items:center}
.land-title{font-family:var(--font-head)!important;font-weight:800;font-size:clamp(30px,5vw,54px);line-height:1.12;color:#0f172a;margin:12px 0}
.land-sub{color:#334155;font-size:16px;max-width:520px}
.land-ghost{background:rgba(255,255,255,.75)!important;color:#0f172a!important;border-color:#fff!important}
.land-stats{display:flex;gap:26px}
.land-stats div{display:flex;flex-direction:column}
.land-stats b{font-size:24px;color:#0f172a}
.land-stats small{color:#475569;font-weight:700}
.land-code-card{background:#0d1528;border:1px solid #22314f;border-radius:14px;padding:18px;box-shadow:0 20px 60px rgba(2,6,23,.45)}
.land-code-card pre{font-family:var(--font-mono)!important;font-size:13.5px;color:#7dd3fc;margin:0;white-space:pre-wrap}
.hc-k{color:#c084fc}.hc-str{color:#86efac}
.land-code-out{margin-top:12px;background:#052e16;border:1px solid #166534;border-radius:10px;padding:10px 12px;color:#bbf7d0;font-family:var(--font-mono)!important;font-size:13px}
.land-section{max-width:1100px;margin:0 auto;padding:48px 22px 8px}
.land-feats .howto{min-height:150px;justify-content:center}
#accTabs .nav-link{border-radius:10px;font-weight:700;font-size:13px;color:var(--muted)}
#accTabs .nav-link.active{background:linear-gradient(135deg,#0ea5e9,#6366f1);color:#fff}
/* ═══ Mobile: editor top compact, preview bottom ═══ */
@media(max-width:991px){
  .land-hero-inner{grid-template-columns:1fr;padding:36px 18px;gap:20px}
  .land-hero{min-height:auto}
  #monacoEditor{height:230px!important}
  #monacoEditor textarea{height:230px!important}
  #pgEditor{height:240px!important}
  #pgEditor textarea{height:240px!important}
  .output-console{max-height:140px;min-height:80px;font-size:13px}
  #codePreview{height:220px}
  .lesson-body{font-size:15px;padding:14px}
  #topbar{flex-wrap:wrap}
  .editor-toolbar{flex-wrap:wrap;row-gap:6px}
  .land-stats{gap:18px}
}

/* ═══ AI Tutor Panel ═══ */
/* English UI mode — বাংলা subtitle লুকাও */
body.lang-en .nav-item .bn{display:none}
.ai-msg{max-width:88%;padding:11px 15px;border-radius:16px;font-size:14.5px;line-height:1.75;white-space:pre-wrap;box-shadow:0 2px 10px rgba(0,0,0,.12);animation:aiPop .2s ease}
@keyframes aiPop{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}
.ai-msg.user{align-self:flex-end;background:linear-gradient(135deg,#0ea5e9,#6366f1);color:#fff;border-bottom-right-radius:5px}
.ai-msg.assistant{align-self:flex-start;background:var(--bg2);border:1px solid var(--border);border-bottom-left-radius:5px}
.ai-fb-note{align-self:center;font-size:11.5px;color:var(--muted);background:rgba(56,189,248,.1);border:1px dashed var(--primary);border-radius:20px;padding:3px 12px}
/* ═══ AI Chat view — input সবসময় নিচে আটকে থাকবে (scroll ছাড়াই) ═══ */
#view-ai .ai-chat-card{display:flex;flex-direction:column;height:calc(100vh - 250px);min-height:430px}
#aiGlobalBox{flex:1 1 auto;min-height:0}
#view-ai .ai-chat-inputbar{position:sticky;bottom:0;background:var(--card);padding-top:8px;z-index:5}
@media(max-width:991px){#view-ai .ai-chat-card{height:calc(100vh - 300px);min-height:380px}}
.ai-msg.error{align-self:flex-start;background:rgba(239,68,68,.1);border:1px solid #ef4444;color:#f87171}
.ai-msg code{font-family:var(--font-mono)!important;background:var(--code-bg);padding:2px 6px;border-radius:6px;font-size:12px}
.ai-msg pre{background:var(--code-bg);border:1px solid var(--border);border-radius:10px;padding:12px;overflow-x:auto;font-size:12.5px;margin:8px 0}
.ai-typing{display:inline-flex;gap:4px;padding:10px 14px;background:var(--bg2);border:1px solid var(--border);border-radius:14px;border-bottom-left-radius:4px}
.ai-typing span{width:6px;height:6px;border-radius:50%;background:var(--primary);animation:blink 1.4s infinite}
.ai-typing span:nth-child(2){animation-delay:.2s}
.ai-typing span:nth-child(3){animation-delay:.4s}
.ai-quiz-card{background:var(--bg2);border:1px solid var(--border);border-radius:10px;padding:12px;margin-bottom:10px}
.ai-quiz-card .q{font-weight:700;margin-bottom:8px}
.ai-quiz-card .opt{display:block;width:100%;text-align:left;margin:4px 0;padding:7px 10px;border-radius:8px;border:1px solid var(--border);background:var(--card);color:var(--text);font-size:13px;transition:.15s}
.ai-quiz-card .opt:hover:not(:disabled){border-color:var(--primary)}
.ai-quiz-card .opt.correct{background:rgba(22,163,74,.15)!important;border-color:#22c55e!important}
.ai-quiz-card .opt.wrong{background:rgba(239,68,68,.15)!important;border-color:#ef4444!important}
.ai-quiz-card .explain{font-size:12.5px;color:var(--muted);margin-top:6px;padding:6px 8px;background:var(--code-bg);border-radius:8px}