/* topicwisepyqs — Telegram-inspired UI */
@import url('https://fonts.googleapis.com/css2?family=Nunito:wght@400;500;600;700;800&family=JetBrains+Mono:wght@400;600&display=swap');

/* ===== TOKENS ===== */
:root {
  --font: 'Nunito', sans-serif;
  --mono: 'JetBrains Mono', monospace;

  /* Light */
  --bg: #f1f3f5;
  --bg2: #ffffff;
  --bg3: #e8edf2;
  --sidebar: #ffffff;
  --sidebar-w: 260px;
  --text: #1c1e21;
  --text2: #65717b;
  --text3: #8a9bb0;
  --border: #dde2e8;
  --primary: #2481cc;
  --primary-h: #1a6fb5;
  --primary-t: rgba(36,129,204,.12);
  --green: #31a24c;
  --green-t: rgba(49,162,76,.12);
  --red: #e74c3c;
  --red-t: rgba(231,76,60,.12);
  --orange: #f39c12;
  --bubble-out: #effdde;
  --bubble-in: #ffffff;
  --shadow: 0 2px 12px rgba(0,0,0,.08);
  --shadow-sm: 0 1px 4px rgba(0,0,0,.06);
  --radius: 12px;
  --radius-sm: 8px;
  --radius-xs: 6px;
  --trans: .18s ease;
  --header-h: 56px;
}

[data-theme="dark"] {
  --bg: #0f1923;
  --bg2: #18222d;
  --bg3: #1e2c3a;
  --sidebar: #17212b;
  --text: #e8f0f8;
  --text2: #8b9caf;
  --text3: #5a6a7a;
  --border: #1f2f3f;
  --primary: #2b9fda;
  --primary-h: #1e8abf;
  --primary-t: rgba(43,159,218,.15);
  --green: #4caf73;
  --green-t: rgba(76,175,115,.15);
  --red: #f05545;
  --red-t: rgba(240,85,69,.15);
  --bubble-out: #2b5278;
  --bubble-in: #182533;
  --shadow: 0 2px 16px rgba(0,0,0,.3);
  --shadow-sm: 0 1px 6px rgba(0,0,0,.2);
}

/* ===== RESET ===== */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{font-size:15px;scroll-behavior:smooth}
body{font-family:var(--font);background:var(--bg);color:var(--text);transition:background var(--trans),color var(--trans);min-height:100vh;overflow-x:hidden}
a{text-decoration:none;color:var(--primary)}
img{max-width:100%;border-radius:var(--radius-xs)}
ul,ol{list-style:none}
button{cursor:pointer;font-family:var(--font)}
input,select,textarea{font-family:var(--font)}

/* ===== SCROLLBAR ===== */
::-webkit-scrollbar{width:5px;height:5px}
::-webkit-scrollbar-track{background:transparent}
::-webkit-scrollbar-thumb{background:var(--border);border-radius:10px}

/* ===== LAYOUT ===== */
.app{display:flex;height:100vh;overflow:hidden}
.sidebar{width:var(--sidebar-w);background:var(--sidebar);border-right:1px solid var(--border);display:flex;flex-direction:column;flex-shrink:0;transition:width var(--trans),transform var(--trans);z-index:100}
.sidebar.collapsed{width:64px}
.main{flex:1;display:flex;flex-direction:column;overflow:hidden}
.header{height:var(--header-h);background:var(--bg2);border-bottom:1px solid var(--border);display:flex;align-items:center;padding:0 20px;gap:12px;flex-shrink:0;position:sticky;top:0;z-index:50}
.content{flex:1;overflow-y:auto;padding:20px}

/* ===== LOGO ===== */
.logo{display:flex;align-items:center;gap:10px;padding:16px 18px;border-bottom:1px solid var(--border)}
.logo-icon{width:38px;height:38px;background:var(--primary);border-radius:10px;display:flex;align-items:center;justify-content:center;flex-shrink:0}
.logo-icon svg{width:22px;height:22px;fill:#fff}
.logo-text{overflow:hidden}
.logo-text strong{display:block;font-size:.92rem;font-weight:800;color:var(--text);letter-spacing:-.3px;white-space:nowrap}
.logo-text span{font-size:.72rem;color:var(--text3);white-space:nowrap}
.sidebar.collapsed .logo-text{display:none}

/* ===== NAV ===== */
.nav{flex:1;overflow-y:auto;padding:10px 8px}
.nav-item{display:flex;align-items:center;gap:12px;padding:10px 10px;border-radius:var(--radius-xs);color:var(--text2);font-size:.88rem;font-weight:600;transition:all var(--trans);cursor:pointer;white-space:nowrap;margin-bottom:2px}
.nav-item:hover{background:var(--primary-t);color:var(--primary)}
.nav-item.active{background:var(--primary-t);color:var(--primary)}
.nav-item i,.nav-item svg{width:18px;height:18px;flex-shrink:0;font-size:18px}
.nav-label{overflow:hidden;text-overflow:ellipsis}
.sidebar.collapsed .nav-label{display:none}
.nav-group{font-size:.7rem;font-weight:700;color:var(--text3);padding:8px 10px 4px;text-transform:uppercase;letter-spacing:.5px}
.sidebar.collapsed .nav-group{display:none}

/* ===== HEADER PARTS ===== */
.h-toggle{background:none;border:none;color:var(--text2);padding:6px;border-radius:8px;display:flex}
.h-toggle:hover{background:var(--bg3);color:var(--text)}
.h-title{font-size:1rem;font-weight:700;flex:1;color:var(--text)}
.h-actions{display:flex;align-items:center;gap:8px}
.h-btn{background:none;border:none;color:var(--text2);padding:7px;border-radius:8px;display:flex;align-items:center;justify-content:center;transition:all var(--trans);position:relative}
.h-btn:hover{background:var(--bg3);color:var(--text)}
.badge{position:absolute;top:3px;right:3px;width:8px;height:8px;background:var(--red);border-radius:50%;border:2px solid var(--bg2)}
.avatar-sm{width:34px;height:34px;border-radius:50%;background:var(--primary-t);display:flex;align-items:center;justify-content:center;overflow:hidden;cursor:pointer;font-weight:700;color:var(--primary);font-size:.85rem}

/* ===== CARDS ===== */
.card{background:var(--bg2);border-radius:var(--radius);border:1px solid var(--border);padding:20px;box-shadow:var(--shadow-sm)}
.card-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:16px}
.card-title{font-size:.95rem;font-weight:700;color:var(--text)}

/* ===== STATS ===== */
.stats-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(180px,1fr));gap:14px;margin-bottom:20px}
.stat-card{background:var(--bg2);border-radius:var(--radius);border:1px solid var(--border);padding:18px;display:flex;align-items:center;gap:14px;box-shadow:var(--shadow-sm);transition:transform var(--trans)}
.stat-card:hover{transform:translateY(-2px)}
.stat-icon{width:44px;height:44px;border-radius:10px;display:flex;align-items:center;justify-content:center;flex-shrink:0;font-size:20px}
.stat-icon.blue{background:var(--primary-t);color:var(--primary)}
.stat-icon.green{background:var(--green-t);color:var(--green)}
.stat-icon.red{background:var(--red-t);color:var(--red)}
.stat-icon.orange{background:rgba(243,156,18,.12);color:var(--orange)}
.stat-val{font-size:1.5rem;font-weight:800;color:var(--text);line-height:1}
.stat-label{font-size:.78rem;color:var(--text3);margin-top:3px}

/* ===== TABLE ===== */
.tbl-wrap{overflow-x:auto}
table{width:100%;border-collapse:collapse;font-size:.875rem}
th{text-align:left;padding:10px 14px;font-size:.75rem;font-weight:700;text-transform:uppercase;letter-spacing:.4px;color:var(--text3);border-bottom:2px solid var(--border)}
td{padding:11px 14px;border-bottom:1px solid var(--border);color:var(--text2);vertical-align:middle}
tr:last-child td{border-bottom:none}
tbody tr:hover td{background:var(--bg3)}
.tbl-actions{display:flex;gap:6px}

/* ===== BUTTONS ===== */
.btn{display:inline-flex;align-items:center;gap:7px;padding:8px 16px;border-radius:var(--radius-xs);font-size:.85rem;font-weight:700;border:none;transition:all var(--trans);cursor:pointer;white-space:nowrap}
.btn-primary{background:var(--primary);color:#fff}
.btn-primary:hover{background:var(--primary-h)}
.btn-outline{background:transparent;border:1.5px solid var(--border);color:var(--text2)}
.btn-outline:hover{border-color:var(--primary);color:var(--primary)}
.btn-danger{background:var(--red-t);color:var(--red)}
.btn-danger:hover{background:var(--red);color:#fff}
.btn-success{background:var(--green-t);color:var(--green)}
.btn-success:hover{background:var(--green);color:#fff}
.btn-sm{padding:5px 11px;font-size:.78rem}
.btn-icon{padding:7px;min-width:34px;justify-content:center}

/* ===== FORMS ===== */
.form-group{margin-bottom:16px}
label{display:block;font-size:.82rem;font-weight:700;color:var(--text2);margin-bottom:5px}
.inp{width:100%;padding:9px 13px;background:var(--bg3);border:1.5px solid var(--border);border-radius:var(--radius-xs);color:var(--text);font-size:.88rem;transition:border var(--trans)}
.inp:focus{outline:none;border-color:var(--primary);background:var(--bg2)}
.inp::placeholder{color:var(--text3)}
select.inp{cursor:pointer}
textarea.inp{resize:vertical;min-height:90px}
.form-row{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.form-hint{font-size:.75rem;color:var(--text3);margin-top:4px}

/* ===== MODAL ===== */
.overlay{position:fixed;inset:0;background:rgba(0,0,0,.45);z-index:200;display:flex;align-items:center;justify-content:center;padding:16px;opacity:0;pointer-events:none;transition:opacity var(--trans)}
.overlay.show{opacity:1;pointer-events:all}
.modal{background:var(--bg2);border-radius:var(--radius);width:100%;max-width:540px;max-height:90vh;overflow-y:auto;box-shadow:0 8px 40px rgba(0,0,0,.25);transform:translateY(20px);transition:transform var(--trans)}
.overlay.show .modal{transform:translateY(0)}
.modal-header{padding:18px 20px;border-bottom:1px solid var(--border);display:flex;align-items:center;justify-content:space-between;position:sticky;top:0;background:var(--bg2);z-index:1}
.modal-title{font-size:.95rem;font-weight:700}
.modal-body{padding:20px}
.modal-footer{padding:14px 20px;border-top:1px solid var(--border);display:flex;gap:10px;justify-content:flex-end}

/* ===== BADGE/TAG ===== */
.tag{display:inline-flex;align-items:center;gap:4px;padding:3px 9px;border-radius:20px;font-size:.75rem;font-weight:700}
.tag-blue{background:var(--primary-t);color:var(--primary)}
.tag-green{background:var(--green-t);color:var(--green)}
.tag-red{background:var(--red-t);color:var(--red)}
.tag-gray{background:var(--bg3);color:var(--text3)}
.tag-orange{background:rgba(243,156,18,.12);color:var(--orange)}

/* ===== TOAST ===== */
#toast-wrap{position:fixed;bottom:24px;right:24px;z-index:999;display:flex;flex-direction:column;gap:10px}
.toast{background:var(--bg2);border:1px solid var(--border);border-radius:var(--radius-xs);padding:12px 16px;box-shadow:var(--shadow);font-size:.85rem;font-weight:600;display:flex;align-items:center;gap:10px;min-width:240px;animation:slideIn .25s ease;border-left:3px solid var(--primary)}
.toast.success{border-left-color:var(--green)}
.toast.error{border-left-color:var(--red)}
@keyframes slideIn{from{transform:translateX(60px);opacity:0}to{transform:translateX(0);opacity:1}}

/* ===== QUIZ SOLVING UI (Telegram-like) ===== */
.quiz-wrap{max-width:700px;margin:0 auto}
.q-bubble{background:var(--bubble-in);border-radius:0 var(--radius) var(--radius) var(--radius);padding:16px 18px;margin-bottom:4px;box-shadow:var(--shadow-sm);border:1px solid var(--border)}
.q-num{font-size:.75rem;font-weight:700;color:var(--primary);margin-bottom:6px}
.q-text{font-size:.95rem;line-height:1.6;color:var(--text)}
.q-img{margin-top:10px;border-radius:var(--radius-xs);max-height:260px;object-fit:contain}
.opts{display:flex;flex-direction:column;gap:8px;margin-top:16px}
.opt{display:flex;align-items:center;gap:12px;padding:11px 16px;background:var(--bg2);border:1.5px solid var(--border);border-radius:var(--radius);cursor:pointer;transition:all .15s;user-select:none}
.opt:hover:not(.locked){border-color:var(--primary);background:var(--primary-t)}
.opt-key{width:28px;height:28px;border-radius:50%;background:var(--bg3);border:1.5px solid var(--border);display:flex;align-items:center;justify-content:center;font-size:.78rem;font-weight:700;flex-shrink:0;transition:all .15s}
.opt-text{font-size:.88rem;color:var(--text);font-weight:500;flex:1}
.opt.correct{border-color:var(--green);background:var(--green-t)}
.opt.correct .opt-key{background:var(--green);border-color:var(--green);color:#fff}
.opt.wrong{border-color:var(--red);background:var(--red-t)}
.opt.wrong .opt-key{background:var(--red);border-color:var(--red);color:#fff}
.opt.locked{cursor:default}

/* Explanation bubble (telegram out-bubble style) */
.exp-bubble{background:var(--bubble-out);border-radius:var(--radius) 0 var(--radius) var(--radius);padding:12px 16px;margin-top:6px;margin-left:40px;font-size:.85rem;line-height:1.55;color:var(--text);box-shadow:var(--shadow-sm);animation:popIn .2s ease;border:1px solid var(--border)}
.exp-label{font-size:.72rem;font-weight:700;color:var(--primary);margin-bottom:5px;display:flex;align-items:center;gap:5px}
@keyframes popIn{from{transform:scale(.95);opacity:0}to{transform:scale(1);opacity:1}}

/* Progress bar */
.q-progress{height:3px;background:var(--bg3);border-radius:2px;overflow:hidden;margin-bottom:16px}
.q-progress-fill{height:100%;background:var(--primary);border-radius:2px;transition:width .4s ease}

/* Timer */
.q-timer{display:flex;align-items:center;gap:6px;font-family:var(--mono);font-size:.9rem;font-weight:600;color:var(--text2);background:var(--bg3);padding:5px 12px;border-radius:20px}
.q-timer.warn{color:var(--red);animation:pulse 1s infinite}
@keyframes pulse{0%,100%{opacity:1}50%{opacity:.5}}

/* Nav dots */
.q-dots{display:flex;flex-wrap:wrap;gap:5px;margin-bottom:16px}
.q-dot{width:28px;height:28px;border-radius:6px;background:var(--bg3);border:1.5px solid var(--border);display:flex;align-items:center;justify-content:center;font-size:.72rem;font-weight:700;cursor:pointer;transition:all .15s;color:var(--text3)}
.q-dot.answered{background:var(--green-t);border-color:var(--green);color:var(--green)}
.q-dot.wrong{background:var(--red-t);border-color:var(--red);color:var(--red)}
.q-dot.current{background:var(--primary);border-color:var(--primary);color:#fff}

/* Result screen */
.result-circle{width:140px;height:140px;border-radius:50%;display:flex;flex-direction:column;align-items:center;justify-content:center;margin:0 auto 20px;border:6px solid var(--primary);background:var(--primary-t)}
.result-pct{font-size:2rem;font-weight:800;color:var(--primary);line-height:1}
.result-label{font-size:.75rem;color:var(--text3);margin-top:3px}
.result-stats{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin-top:20px}
.rs-item{background:var(--bg3);border-radius:var(--radius-sm);padding:14px;text-align:center}
.rs-val{font-size:1.4rem;font-weight:800}
.rs-key{font-size:.75rem;color:var(--text3);margin-top:3px}

/* ===== CATEGORY TREE ===== */
.cat-tree{display:flex;flex-direction:column;gap:2px}
.cat-row{display:flex;align-items:center;gap:8px;padding:8px 10px;border-radius:var(--radius-xs);transition:background var(--trans);cursor:pointer}
.cat-row:hover{background:var(--bg3)}
.cat-indent{display:flex;align-items:center;gap:8px;flex:1}
.cat-toggle{width:20px;height:20px;display:flex;align-items:center;justify-content:center;color:var(--text3);flex-shrink:0;transition:transform var(--trans)}
.cat-toggle.open{transform:rotate(90deg)}
.cat-icon{width:28px;height:28px;border-radius:6px;display:flex;align-items:center;justify-content:center;font-size:14px;flex-shrink:0}
.cat-name{font-size:.88rem;font-weight:600;color:var(--text);flex:1}
.cat-count{font-size:.75rem;color:var(--text3)}

/* ===== DRAG AREA ===== */
.drop-zone{border:2px dashed var(--border);border-radius:var(--radius);padding:30px;text-align:center;transition:all var(--trans);cursor:pointer}
.drop-zone:hover,.drop-zone.drag-over{border-color:var(--primary);background:var(--primary-t)}
.drop-zone i{font-size:2rem;color:var(--text3);margin-bottom:8px;display:block}
.drop-zone p{font-size:.85rem;color:var(--text2)}
.drop-zone span{color:var(--primary);font-weight:700}

/* ===== STUDENT SIDEBAR (quiz session) ===== */
.session-sidebar{width:220px;background:var(--bg2);border-left:1px solid var(--border);padding:16px;flex-shrink:0;overflow-y:auto}

/* ===== SEARCH BAR ===== */
.search-bar{display:flex;align-items:center;gap:8px;background:var(--bg3);border:1.5px solid var(--border);border-radius:var(--radius-xs);padding:7px 12px;flex:1;max-width:320px}
.search-bar input{background:none;border:none;outline:none;color:var(--text);font-size:.875rem;width:100%}
.search-bar i{color:var(--text3)}

/* ===== PAGINATION ===== */
.pagination{display:flex;align-items:center;gap:6px;margin-top:16px;justify-content:center}
.page-btn{width:34px;height:34px;border-radius:var(--radius-xs);background:var(--bg3);border:1.5px solid var(--border);display:flex;align-items:center;justify-content:center;font-size:.82rem;font-weight:700;color:var(--text2);cursor:pointer;transition:all var(--trans)}
.page-btn:hover,.page-btn.active{background:var(--primary);border-color:var(--primary);color:#fff}

/* ===== ALERTS ===== */
.alert{padding:12px 16px;border-radius:var(--radius-xs);font-size:.85rem;font-weight:600;display:flex;align-items:flex-start;gap:10px;margin-bottom:16px}
.alert-info{background:var(--primary-t);color:var(--primary);border-left:3px solid var(--primary)}
.alert-success{background:var(--green-t);color:var(--green);border-left:3px solid var(--green)}
.alert-danger{background:var(--red-t);color:var(--red);border-left:3px solid var(--red)}
.alert-warn{background:rgba(243,156,18,.12);color:var(--orange);border-left:3px solid var(--orange)}

/* ===== SWITCH TOGGLE ===== */
.switch{position:relative;display:inline-flex;align-items:center;gap:8px;cursor:pointer;font-size:.85rem;font-weight:600;color:var(--text2)}
.switch input{opacity:0;width:0;height:0}
.switch-track{width:42px;height:24px;background:var(--border);border-radius:12px;position:relative;transition:background var(--trans);flex-shrink:0}
.switch input:checked+.switch-track{background:var(--primary)}
.switch-track::after{content:'';position:absolute;width:18px;height:18px;background:#fff;border-radius:50%;top:3px;left:3px;transition:left var(--trans);box-shadow:0 1px 4px rgba(0,0,0,.2)}
.switch input:checked+.switch-track::after{left:21px}

/* ===== EMPTY STATE ===== */
.empty{text-align:center;padding:50px 20px;color:var(--text3)}
.empty i{font-size:3rem;margin-bottom:12px;display:block}
.empty p{font-size:.9rem}

/* ===== LOGIN PAGE ===== */
.login-page{min-height:100vh;display:flex;align-items:center;justify-content:center;background:var(--bg);padding:20px}
.login-box{background:var(--bg2);border-radius:var(--radius);border:1px solid var(--border);padding:36px;width:100%;max-width:400px;box-shadow:var(--shadow)}
.login-logo{text-align:center;margin-bottom:28px}
.login-logo .logo-icon{width:56px;height:56px;margin:0 auto 10px;border-radius:14px}
.login-logo h1{font-size:1.3rem;font-weight:800;color:var(--text)}
.login-logo p{font-size:.82rem;color:var(--text3);margin-top:3px}

/* ===== RESPONSIVE ===== */
@media(max-width:768px){
  .sidebar{position:fixed;left:-260px;height:100%;box-shadow:var(--shadow);transition:left var(--trans)}
  .sidebar.mobile-open{left:0}
  .sidebar.collapsed{width:260px;left:-260px}
  .form-row{grid-template-columns:1fr}
  .stats-grid{grid-template-columns:1fr 1fr}
  .content{padding:14px}
  .session-sidebar{display:none}
}
@media(max-width:480px){
  .stats-grid{grid-template-columns:1fr}
}

/* ===== STUDENT FRONT SPECIFIC ===== */
.hero{background:var(--primary);color:#fff;border-radius:var(--radius);padding:28px 24px;margin-bottom:20px;position:relative;overflow:hidden}
.hero::after{content:'';position:absolute;top:-30px;right:-30px;width:180px;height:180px;background:rgba(255,255,255,.08);border-radius:50%}
.hero h2{font-size:1.3rem;font-weight:800}
.hero p{font-size:.85rem;opacity:.85;margin-top:6px}
.quiz-card{background:var(--bg2);border:1px solid var(--border);border-radius:var(--radius);padding:16px;transition:all var(--trans);cursor:pointer}
.quiz-card:hover{border-color:var(--primary);box-shadow:0 4px 20px rgba(36,129,204,.15);transform:translateY(-2px)}
.quiz-card h4{font-size:.9rem;font-weight:700;color:var(--text);margin-bottom:6px}
.quiz-meta{display:flex;flex-wrap:wrap;gap:8px;margin-top:10px}
.quiz-meta span{display:flex;align-items:center;gap:4px;font-size:.75rem;color:var(--text3)}

/* PWA install banner */
#pwa-banner{position:fixed;bottom:0;left:0;right:0;background:var(--primary);color:#fff;padding:12px 20px;display:flex;align-items:center;justify-content:space-between;z-index:998;transform:translateY(100%);transition:transform .4s ease;gap:12px}
#pwa-banner.show{transform:translateY(0)}
#pwa-banner p{font-size:.85rem;font-weight:600;flex:1}
#pwa-banner .btn-install{background:#fff;color:var(--primary);padding:7px 16px;border-radius:20px;font-weight:700;font-size:.82rem;border:none;cursor:pointer}
#pwa-banner .btn-dismiss{background:rgba(255,255,255,.2);border:none;color:#fff;padding:7px 12px;border-radius:20px;cursor:pointer;font-size:.82rem}

/* ===== DARK MODE TOGGLE ===== */
.theme-btn{background:none;border:none;cursor:pointer;padding:7px;border-radius:8px;color:var(--text2);display:flex;transition:all var(--trans)}
.theme-btn:hover{background:var(--bg3);color:var(--text)}

/* ===== MY BATCHES PAGE ===== */
.paid-batch-card{border-left:3px solid #e67e22}
.tag-orange{background:rgba(243,156,18,.12);color:#e67e22}

/* Payment modal */
.pay-price-badge{display:inline-block;font-size:1.8rem;font-weight:800;color:var(--primary);background:var(--primary-t);padding:8px 28px;border-radius:40px;margin:4px auto 0;letter-spacing:.02em}

/* WhatsApp button */
.btn-wa{background:#25d366;color:#fff;display:inline-flex;align-items:center;gap:8px;padding:9px 20px;border-radius:var(--radius-xs);font-weight:700;font-size:.9rem;text-decoration:none;transition:background var(--trans)}
.btn-wa:hover{background:#1ebe5d}
.btn-wa i{font-size:1.1rem}

@media(max-width:480px){
  .pay-price-badge{font-size:1.4rem;padding:6px 20px}
}

/* ═══════════════════════════════════════════════════════════
   PREMIUM UPGRADE — Telegram Deep Breeze + Logo Styles
   ═══════════════════════════════════════════════════════════ */

/* ── Deeper dark palette overrides ──────────────────────── */
[data-theme="dark"] {
  --bg:      #0d1117;
  --bg2:     #161b22;
  --bg3:     #21262d;
  --sidebar: #161b22;
  --border:  #30363d;
  --text:    #e6edf3;
  --text2:   #8b949e;
  --text3:   #484f58;
  --primary:        #2b9fda;
  --primary-h:      #1d8ec9;
  --primary-t:      rgba(43,159,218,.14);
  --green:          #3fb950;
  --green-t:        rgba(63,185,80,.14);
  --red:            #f85149;
  --red-t:          rgba(248,81,73,.14);
  --orange:         #d29922;
  --bubble-out:     #1c4266;
  --bubble-in:      #161b22;
  --shadow:         0 2px 20px rgba(0,0,0,.5);
  --shadow-sm:      0 1px 6px rgba(0,0,0,.35);
}

/* ── Logo image in sidebar ───────────────────────────────── */
.logo-img-wrap { width:38px;height:38px;flex-shrink:0 }
.logo-img { width:38px;height:38px;border-radius:10px;object-fit:cover;display:block }
.sidebar.collapsed .logo-text { display:none }
.sidebar.collapsed .logo-img-wrap { width:32px;height:32px }
.sidebar.collapsed .logo-img { width:32px;height:32px }

/* ── Admin page logo (reuse same img) ───────────────────── */
.admin-logo-img { width:36px;height:36px;border-radius:9px;object-fit:cover }

/* ── Sidebar Breeze depth ────────────────────────────────── */
.sidebar {
  background: var(--sidebar);
  box-shadow: 2px 0 16px rgba(0,0,0,.06);
}
[data-theme="dark"] .sidebar { box-shadow: 2px 0 20px rgba(0,0,0,.4); }

/* ── Nav item premium feel ───────────────────────────────── */
.nav-item {
  border-radius: 10px;
  padding: 10px 12px;
  font-weight: 600;
  font-size: .875rem;
  letter-spacing: -.01em;
  transition: background .14s, color .14s, transform .12s;
}
.nav-item:hover  { transform: translateX(2px); }
.nav-item.active { font-weight: 700; }
.nav-item i      { font-size: 17px; min-width: 20px; text-align: center; }

/* ── Card premium ────────────────────────────────────────── */
.card {
  border-radius: 14px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow .2s;
}
.card:hover { box-shadow: var(--shadow); }

/* ── Stat card premium ───────────────────────────────────── */
.stat-card { border-radius: 14px; }

/* ── Header blur backdrop ────────────────────────────────── */
.header {
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  background: rgba(var(--bg2-raw,255,255,255),.85);
}
[data-theme="dark"] .header { background: rgba(22,27,34,.9); }

/* ── Button premium ──────────────────────────────────────── */
.btn {
  border-radius: 10px;
  font-weight: 700;
  letter-spacing: -.01em;
  transition: all .15s cubic-bezier(.4,0,.2,1);
}
.btn-primary { box-shadow: 0 2px 8px rgba(43,159,218,.3); }
.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 4px 14px rgba(43,159,218,.4); }
.btn-sm { border-radius: 8px; }

/* ── Input premium ───────────────────────────────────────── */
.inp {
  border-radius: 10px;
  transition: border-color .15s, box-shadow .15s;
}
.inp:focus { box-shadow: 0 0 0 3px var(--primary-t); }

/* ── Login box premium ───────────────────────────────────── */
.login-box {
  border-radius: 20px;
  box-shadow: 0 8px 40px rgba(0,0,0,.12);
  padding: 38px 36px;
  border: 1px solid var(--border);
}
[data-theme="dark"] .login-box { box-shadow: 0 8px 40px rgba(0,0,0,.5); }

/* ── Quiz row card ───────────────────────────────────────── */
.quiz-row {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 16px;
  border-radius: 12px;
  border: 1.5px solid var(--border);
  background: var(--bg2);
  margin-bottom: 8px;
  text-decoration: none;
  transition: all .18s cubic-bezier(.4,0,.2,1);
  color: var(--text);
}
.quiz-row:hover {
  border-color: var(--primary);
  background: var(--primary-t);
  transform: translateX(3px);
  box-shadow: 0 2px 12px rgba(43,159,218,.15);
}
.quiz-row-icon {
  width: 42px; height: 42px;
  border-radius: 10px;
  background: var(--primary-t);
  color: var(--primary);
  display: flex; align-items: center; justify-content: center;
  font-size: 18px; flex-shrink: 0;
}
.quiz-row-title { font-size: .92rem; font-weight: 700; color: var(--text); }
.quiz-row-meta  { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 5px; }
.quiz-row-meta span { font-size: .73rem; color: var(--text3); display: flex; align-items: center; gap: 4px; }
.quiz-row-body  { flex: 1; min-width: 0; }

/* ── Leaderboard pill ────────────────────────────────────── */
.lb-pill {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 4px 10px;
  border-radius: 20px;
  font-size: .72rem;
  font-weight: 700;
  background: rgba(255,193,7,.12);
  color: #f59e0b;
  cursor: pointer;
  border: 1.5px solid rgba(255,193,7,.25);
  text-decoration: none;
  transition: all .15s;
}
.lb-pill:hover { background: rgba(255,193,7,.2); color: #d97706; }

/* ── Saved question sidebar (quiz page) ──────────────────── */
#saved-drawer {
  position: fixed;
  right: -340px;
  top: 0; bottom: 0;
  width: 320px;
  background: var(--bg2);
  border-left: 1px solid var(--border);
  z-index: 300;
  transition: right .3s cubic-bezier(.4,0,.2,1);
  display: flex;
  flex-direction: column;
  box-shadow: -4px 0 24px rgba(0,0,0,.15);
}
#saved-drawer.open { right: 0; }
.saved-drawer-hd {
  padding: 16px 18px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-weight: 700;
  font-size: .92rem;
  flex-shrink: 0;
}
.saved-drawer-body { flex: 1; overflow-y: auto; padding: 12px; }
.saved-q-item {
  background: var(--bg3);
  border-radius: 10px;
  padding: 12px;
  margin-bottom: 8px;
  font-size: .82rem;
  line-height: 1.5;
  color: var(--text2);
  border-left: 3px solid var(--primary);
}
.saved-q-item .sq-qtext { color: var(--text); font-weight: 600; margin-bottom: 6px; font-size: .85rem; }
.saved-q-item .sq-ans { color: var(--green); font-size: .78rem; font-weight: 700; }
.saved-q-item .sq-exp { margin-top: 6px; font-size: .78rem; color: var(--text3); border-top: 1px solid var(--border); padding-top: 6px; }
.saved-q-empty { text-align: center; padding: 40px 20px; color: var(--text3); }
.saved-q-empty i { font-size: 2.5rem; margin-bottom: 10px; display: block; }

/* ── Desktop quiz explanation panel ─────────────────────── */
@media (min-width: 900px) {
  .quiz-desktop-layout {
    display: grid;
    grid-template-columns: 1fr 380px;
    gap: 20px;
    align-items: start;
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 16px 80px;
  }
  .quiz-main-col { min-width: 0; }
  .quiz-exp-col {
    position: sticky;
    top: 68px;
    max-height: calc(100vh - 88px);
    overflow-y: auto;
  }
  .quiz-scroll-container { max-width: 100%; padding: 0; }
  .exp-panel {
    background: var(--bg2);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 20px;
    display: none;
    animation: flipIn .5s cubic-bezier(.22,1,.36,1) both;
  }
  .exp-panel.visible { display: block; }
  @keyframes flipIn {
    from { opacity: 0; transform: perspective(600px) rotateY(-12deg) translateX(20px); }
    to   { opacity: 1; transform: perspective(600px) rotateY(0) translateX(0); }
  }
  .exp-panel-label {
    font-size: .75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: .07em;
    color: var(--primary);
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 6px;
  }
  .exp-panel-body {
    font-size: .87rem;
    line-height: 1.7;
    color: var(--text2);
  }
}
@media (max-width: 899px) {
  .quiz-exp-col { display: none !important; }
}

/* ── Continue attempt button ─────────────────────────────── */
.btn-continue {
  background: linear-gradient(135deg, var(--primary), #6c63ff);
  color: #fff;
  border: none;
  box-shadow: 0 3px 12px rgba(43,159,218,.35);
}
.btn-continue:hover {
  transform: translateY(-1px);
  box-shadow: 0 5px 18px rgba(43,159,218,.45);
}

/* ── History "Continue" row ──────────────────────────────── */
.history-continue-btn {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 5px 12px;
  border-radius: 20px;
  font-size: .75rem;
  font-weight: 700;
  background: var(--primary-t);
  color: var(--primary);
  border: 1.5px solid var(--primary);
  text-decoration: none;
  transition: all .15s;
  white-space: nowrap;
}
.history-continue-btn:hover { background: var(--primary); color: #fff; }

/* ── Saved questions page ────────────────────────────────── */
.sq-card {
  background: var(--bg2);
  border: 1.5px solid var(--border);
  border-radius: 14px;
  padding: 16px;
  margin-bottom: 12px;
  border-left: 4px solid var(--primary);
  transition: box-shadow .2s;
}
.sq-card:hover { box-shadow: var(--shadow); }
.sq-card-q { font-size: .92rem; font-weight: 700; color: var(--text); margin-bottom: 10px; line-height: 1.55; }
.sq-card-ans { display: flex; align-items: center; gap: 6px; font-size: .78rem; font-weight: 700; color: var(--green); margin-bottom: 8px; }
.sq-card-exp { font-size: .82rem; line-height: 1.6; color: var(--text2); background: var(--bg3); border-radius: 8px; padding: 10px 12px; }
.sq-card-meta { font-size: .72rem; color: var(--text3); margin-top: 10px; display: flex; align-items: center; justify-content: space-between; }
.sq-unsave-btn { background: none; border: 1.5px solid var(--border); border-radius: 20px; color: var(--red); font-size: .72rem; font-weight: 700; cursor: pointer; padding: 3px 10px; transition: all .15s; }
.sq-unsave-btn:hover { background: var(--red-t); border-color: var(--red); }

/* ── Leaderboard per-quiz ────────────────────────────────── */
.lb-rank-1 { color: #f59e0b; }
.lb-rank-2 { color: #9ca3af; }
.lb-rank-3 { color: #b45309; }
.lb-medal  { font-size: 1.1rem; }

/* ── Mobile overlay when drawer open ────────────────────── */
#drawer-overlay {
  position: fixed; inset: 0;
  background: rgba(0,0,0,.4);
  z-index: 299;
  display: none;
  backdrop-filter: blur(2px);
}
#drawer-overlay.show { display: block; }

/* ── Courses tag (previously "Batches") ─────────────────── */
.course-badge {
  display: inline-flex; align-items: center; gap: 5px;
  padding: 4px 10px;
  border-radius: 20px;
  font-size: .72rem; font-weight: 700;
  background: var(--primary-t); color: var(--primary);
}

/* ── Option italic (quiz) ────────────────────────────────── */
.opt-text { font-style: italic; }

/* ── Smoother toast ──────────────────────────────────────── */
.toast {
  border-radius: 12px;
  backdrop-filter: blur(8px);
  box-shadow: 0 4px 20px rgba(0,0,0,.15);
}

/* ── Scrollbar Breeze ────────────────────────────────────── */
::-webkit-scrollbar { width: 5px; height: 5px; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 10px; }