@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&family=JetBrains+Mono:wght@400;500;600&display=swap');

:root {
  --brand-primary: #7C6EF7;
  --brand-secondary: #A78BFA;
  --brand-accent: #06D6A0;
  --brand-danger: #F43F5E;
  --brand-warning: #FBBF24;
  --bg: #09090F;
  --bg2: #0E0E18;
  --bg3: #13131F;
  --surface: #1A1A28;
  --surface2: #202030;
  --surface3: #262638;
  --text: #F0F0F8;
  --text2: #C8C8DC;
  --muted: #8080A0;
  --muted2: #5A5A78;
  --border: rgba(255,255,255,0.06);
  --border2: rgba(255,255,255,0.1);
  --border3: rgba(124,110,247,0.2);
  --grad: linear-gradient(135deg,#7C6EF7 0%,#A78BFA 50%,#06D6A0 100%);
  --grad2: linear-gradient(135deg,#7C6EF7,#A78BFA);
  --glow: 0 0 40px rgba(124,110,247,0.15);
  --r: 10px; --rl: 16px; --rxl: 24px;
  --font: 'Inter',sans-serif;
  --mono: 'JetBrains Mono',monospace;
  --trans: all 0.2s cubic-bezier(0.4,0,0.2,1);
  --success: #06D6A0;
  --danger: #F43F5E;
}

*,*::before,*::after{box-sizing:border-box;margin:0;padding:0;}
html{scroll-behavior:smooth;}
body{font-family:var(--font);background:var(--bg);color:var(--text);line-height:1.6;-webkit-font-smoothing:antialiased;overflow-x:hidden;}
a{color:inherit;text-decoration:none;}
img{max-width:100%;}
input,select,textarea,button{font-family:var(--font);}
::-webkit-scrollbar{width:4px;height:4px;}
::-webkit-scrollbar-track{background:transparent;}
::-webkit-scrollbar-thumb{background:var(--surface3);border-radius:2px;}

.grad-text{background:var(--grad);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;}

/* ── LAYOUT ── */
.layout{display:flex;min-height:100vh;}
.main-content{flex:1;padding:28px 32px;overflow-y:auto;min-width:0;}
.flex-between{display:flex;align-items:center;justify-content:space-between;gap:12px;}
.flex-center{display:flex;align-items:center;justify-content:center;}
.grid-2{display:grid;grid-template-columns:1fr 1fr;gap:16px;}
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;}
.grid-4{display:grid;grid-template-columns:repeat(4,1fr);gap:14px;}
.mt-4{margin-top:16px;}.mt-6{margin-top:24px;}
.mb-4{margin-bottom:16px;}.mb-6{margin-bottom:24px;}
.w-full{width:100%;}

/* ── SIDEBAR ── */
.sidebar{width:220px;min-height:100vh;background:var(--bg2);border-right:1px solid var(--border);display:flex;flex-direction:column;position:sticky;top:0;height:100vh;overflow-y:auto;flex-shrink:0;z-index:100;transition:var(--trans);}
.sidebar-logo{padding:22px 18px 16px;font-size:0.95rem;font-weight:800;letter-spacing:-0.03em;background:var(--grad2);-webkit-background-clip:text;-webkit-text-fill-color:transparent;border-bottom:1px solid var(--border);}
.sidebar-logo span{display:block;font-size:0.6rem;font-weight:500;letter-spacing:0.08em;text-transform:uppercase;background:none;-webkit-text-fill-color:var(--muted);margin-top:2px;}
.sidebar-nav{padding:12px 10px;flex:1;}
.sidebar-section-label{font-size:0.58rem;font-weight:700;text-transform:uppercase;letter-spacing:0.12em;color:var(--muted2);padding:10px 10px 5px;}
.sidebar-link{display:flex;align-items:center;gap:9px;padding:8px 10px;border-radius:var(--r);font-size:0.8rem;font-weight:500;color:var(--muted);transition:var(--trans);margin-bottom:1px;cursor:pointer;text-decoration:none;}
.sidebar-link:hover{background:var(--surface);color:var(--text);}
.sidebar-link.active{background:rgba(124,110,247,0.12);color:var(--brand-primary);font-weight:600;border-left:3px solid var(--brand-primary);}
.sidebar-link .icon{width:16px;flex-shrink:0;display:inline-flex;}
.sidebar-bottom{padding:12px 10px;border-top:1px solid var(--border);}

/* ── MOBILE SIDEBAR ── */
.mobile-menu-btn{display:none;background:none;border:none;color:var(--text);cursor:pointer;padding:8px;}
.sidebar-overlay{display:none;position:fixed;inset:0;background:rgba(0,0,0,0.6);z-index:99;backdrop-filter:blur(4px);}
.sidebar-overlay.show{display:block;}

/* ── NAVBAR (public pages) ── */
.navbar{position:fixed;top:0;left:0;right:0;height:60px;background:rgba(9,9,15,0.9);backdrop-filter:blur(20px);border-bottom:1px solid var(--border);display:flex;align-items:center;justify-content:space-between;padding:0 40px;z-index:1000;}
.nav-logo{font-size:1rem;font-weight:800;letter-spacing:-0.03em;background:var(--grad2);-webkit-background-clip:text;-webkit-text-fill-color:transparent;}
.nav-links{display:flex;align-items:center;gap:24px;}
.nav-links a{font-size:0.82rem;font-weight:500;color:var(--muted);transition:var(--trans);}
.nav-links a:hover{color:var(--text);}

/* ── CARDS ── */
.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--rl);padding:20px;}
.card-hover{transition:var(--trans);cursor:pointer;}
.card-hover:hover{border-color:var(--border3);box-shadow:var(--glow);transform:translateY(-2px);}

/* ── STATS ── */
.stats-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:14px;margin-bottom:20px;}
.stat-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--rl);padding:18px 20px;transition:var(--trans);}
.stat-card:hover{border-color:var(--border3);box-shadow:var(--glow);}
.stat-icon{margin-bottom:10px;color:var(--brand-primary);}
.stat-value{font-size:1.7rem;font-weight:800;letter-spacing:-0.03em;line-height:1;}
.stat-label{font-size:0.72rem;color:var(--muted);margin-top:4px;font-weight:500;}

/* ── BUTTONS ── */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;padding:9px 18px;border-radius:var(--r);font-size:0.8rem;font-weight:600;border:none;cursor:pointer;transition:var(--trans);font-family:var(--font);white-space:nowrap;text-decoration:none;}
.btn:disabled{opacity:0.5;cursor:not-allowed;}
.btn-primary{background:var(--grad2);color:#fff;box-shadow:0 4px 16px rgba(124,110,247,0.3);}
.btn-primary:hover:not(:disabled){transform:translateY(-1px);box-shadow:0 6px 24px rgba(124,110,247,0.45);}
.btn-outline{background:transparent;border:1px solid var(--border2);color:var(--text2);}
.btn-outline:hover:not(:disabled){border-color:var(--border3);color:var(--text);background:var(--surface2);}
.btn-danger{background:rgba(244,63,94,0.15);border:1px solid rgba(244,63,94,0.3);color:var(--brand-danger);}
.btn-danger:hover:not(:disabled){background:var(--brand-danger);color:white;}
.btn-success{background:rgba(6,214,160,0.12);border:1px solid rgba(6,214,160,0.25);color:var(--brand-accent);}
.btn-success:hover:not(:disabled){background:var(--brand-accent);color:#000;}
.btn-sm{padding:5px 12px;font-size:0.74rem;}
.btn-lg{padding:12px 26px;font-size:0.9rem;}

/* ── FORMS ── */
.form-group{margin-bottom:16px;}
.form-label{display:block;font-size:0.7rem;font-weight:600;color:var(--muted);text-transform:uppercase;letter-spacing:0.06em;margin-bottom:6px;}
.form-control{width:100%;background:var(--bg3);border:1px solid var(--border2);border-radius:var(--r);color:var(--text);font-size:0.84rem;padding:10px 13px;transition:var(--trans);font-family:var(--font);outline:none;}
.form-control:focus{border-color:var(--brand-primary);box-shadow:0 0 0 3px rgba(124,110,247,0.1);}
.form-control::placeholder{color:var(--muted2);}
select.form-control{cursor:pointer;}
textarea.form-control{resize:vertical;min-height:90px;}

/* ── FILE DROP ── */
.file-drop{border:2px dashed var(--border2);border-radius:var(--rl);padding:32px 20px;text-align:center;cursor:pointer;transition:var(--trans);background:var(--bg3);}
.file-drop:hover,.file-drop.dragover{border-color:var(--brand-primary);background:rgba(124,110,247,0.04);}
.file-drop input{display:none;}

/* ── TOGGLE ── */
.toggle{position:relative;display:inline-flex;align-items:center;cursor:pointer;}
.toggle input{display:none;}
.toggle-slider{width:40px;height:22px;background:var(--surface3);border-radius:11px;transition:var(--trans);position:relative;}
.toggle-slider::after{content:'';position:absolute;top:3px;left:3px;width:16px;height:16px;background:white;border-radius:50%;transition:var(--trans);}
.toggle input:checked+.toggle-slider{background:var(--brand-primary);}
.toggle input:checked+.toggle-slider::after{transform:translateX(18px);}

/* ── ALERTS & TOASTS ── */
.alert{border-radius:var(--r);padding:10px 13px;font-size:0.8rem;margin-bottom:14px;display:none;}
.alert.show{display:block;}
.alert-error{background:rgba(244,63,94,0.1);border:1px solid rgba(244,63,94,0.25);color:#F87171;}
.alert-success{background:rgba(6,214,160,0.1);border:1px solid rgba(6,214,160,0.25);color:#34D399;}
.alert-info{background:rgba(124,110,247,0.08);border:1px solid rgba(124,110,247,0.2);color:var(--brand-secondary);}
.toast-container{position:fixed;top:16px;right:16px;z-index:9999;display:flex;flex-direction:column;gap:8px;max-width:320px;}
.toast{display:flex;align-items:center;gap:10px;background:var(--surface2);border:1px solid var(--border2);border-radius:var(--r);padding:11px 14px;font-size:0.8rem;box-shadow:0 8px 32px rgba(0,0,0,0.4);animation:toastIn 0.3s ease;word-break:break-word;}
.toast.success{border-color:rgba(6,214,160,0.3);}
.toast.error{border-color:rgba(244,63,94,0.3);}
.toast.info{border-color:rgba(124,110,247,0.3);}
@keyframes toastIn{from{opacity:0;transform:translateX(20px);}to{opacity:1;transform:translateX(0);}}

/* ── MODALS ── */
.modal-overlay{position:fixed;inset:0;background:rgba(0,0,0,0.75);backdrop-filter:blur(8px);z-index:500;display:none;align-items:center;justify-content:center;padding:16px;}
.modal-overlay.show{display:flex;}
.modal{background:var(--bg2);border:1px solid var(--border2);border-radius:var(--rxl);padding:28px;width:100%;max-width:520px;max-height:92vh;overflow-y:auto;animation:modalIn 0.25s ease;}
@keyframes modalIn{from{opacity:0;transform:scale(0.96) translateY(10px);}to{opacity:1;transform:scale(1) translateY(0);}}
.modal-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:20px;}
.modal-title{font-size:0.95rem;font-weight:700;}
.modal-close{background:none;border:none;color:var(--muted);cursor:pointer;padding:4px;font-size:1.1rem;transition:var(--trans);line-height:1;}
.modal-close:hover{color:var(--text);}

/* ── TABLES ── */
.table-wrap{overflow-x:auto;-webkit-overflow-scrolling:touch;}
table{width:100%;border-collapse:collapse;min-width:500px;}
th{font-size:0.64rem;font-weight:700;text-transform:uppercase;letter-spacing:0.1em;color:var(--muted2);padding:9px 14px;text-align:left;border-bottom:1px solid var(--border);}
td{padding:11px 14px;border-bottom:1px solid var(--border);font-size:0.8rem;vertical-align:middle;}
tr:last-child td{border-bottom:none;}
tr:hover td{background:rgba(255,255,255,0.02);}

/* ── BADGES ── */
.badge{display:inline-flex;align-items:center;gap:4px;padding:3px 9px;border-radius:50px;font-size:0.66rem;font-weight:700;}
.badge-pending{background:rgba(251,191,36,0.12);color:#FBBF24;border:1px solid rgba(251,191,36,0.2);}
.badge-approved,.badge-active{background:rgba(6,214,160,0.1);color:#06D6A0;border:1px solid rgba(6,214,160,0.2);}
.badge-rejected,.badge-danger{background:rgba(244,63,94,0.1);color:#F43F5E;border:1px solid rgba(244,63,94,0.15);}
.badge-info{background:rgba(124,110,247,0.1);color:var(--brand-secondary);border:1px solid rgba(124,110,247,0.2);}

/* ── PROGRESS ── */
.progress-bar{height:5px;background:var(--surface3);border-radius:3px;overflow:hidden;}
.progress-fill{height:100%;background:var(--grad2);border-radius:3px;transition:width 0.6s ease;}

/* ── TABS ── */
.tab-bar{display:flex;gap:4px;background:var(--bg3);padding:4px;border-radius:var(--r);width:fit-content;margin-bottom:20px;flex-wrap:wrap;}
.tab-btn{padding:6px 16px;border-radius:calc(var(--r) - 2px);border:none;background:transparent;color:var(--muted);font-size:0.76rem;font-weight:600;cursor:pointer;transition:var(--trans);font-family:var(--font);}
.tab-btn.active{background:var(--surface2);color:var(--text);box-shadow:0 2px 8px rgba(0,0,0,0.3);}

/* ── AVATAR ── */
.avatar{width:34px;height:34px;border-radius:50%;background:var(--grad2);display:flex;align-items:center;justify-content:center;font-weight:700;font-size:0.8rem;overflow:hidden;flex-shrink:0;}
.avatar img{width:100%;height:100%;object-fit:cover;}
.avatar-lg{width:50px;height:50px;font-size:0.95rem;}

/* ── LOADER ── */
.loader{width:14px;height:14px;border:2px solid rgba(255,255,255,0.2);border-top-color:white;border-radius:50%;animation:spin 0.7s linear infinite;display:inline-block;}
@keyframes spin{to{transform:rotate(360deg);}}

/* ── MODULE/LESSON TREE ── */
.module-block{background:var(--surface);border:1px solid var(--border);border-radius:var(--rl);margin-bottom:12px;overflow:hidden;}
.module-header{padding:14px 18px;display:flex;align-items:center;gap:12px;cursor:pointer;transition:var(--trans);user-select:none;flex-wrap:wrap;gap:8px;}
.module-header:hover{background:var(--surface2);}
.module-num{width:28px;height:28px;border-radius:7px;background:var(--grad2);display:flex;align-items:center;justify-content:center;font-size:0.72rem;font-weight:800;color:white;flex-shrink:0;}
.module-lessons{border-top:1px solid var(--border);}
.lesson-row{display:flex;align-items:center;gap:10px;padding:10px 18px;border-bottom:1px solid var(--border);cursor:pointer;transition:var(--trans);flex-wrap:wrap;}
.lesson-row:last-child{border-bottom:none;}
.lesson-row:hover{background:rgba(124,110,247,0.03);}
.lesson-type-icon{width:28px;height:28px;border-radius:7px;display:flex;align-items:center;justify-content:center;flex-shrink:0;}
.lesson-type-video{background:rgba(124,110,247,0.12);color:var(--brand-primary);}
.lesson-type-pdf{background:rgba(244,63,94,0.1);color:var(--brand-danger);}
.lesson-type-document{background:rgba(6,214,160,0.1);color:var(--brand-accent);}
.lesson-type-quiz{background:rgba(167,139,250,0.1);color:var(--brand-secondary);}

/* ── AI BOX ── */
.ai-box{background:linear-gradient(135deg,rgba(124,110,247,0.06),rgba(6,214,160,0.03));border:1px solid rgba(124,110,247,0.15);border-radius:var(--rl);overflow:hidden;}
.ai-header{padding:12px 16px;display:flex;align-items:center;gap:8px;border-bottom:1px solid rgba(124,110,247,0.1);background:rgba(124,110,247,0.04);}
.ai-indicator{width:7px;height:7px;border-radius:50%;background:var(--brand-accent);animation:pulse 2s infinite;}
@keyframes pulse{0%,100%{opacity:1;box-shadow:0 0 0 0 rgba(6,214,160,0.4);}50%{opacity:.8;box-shadow:0 0 0 5px rgba(6,214,160,0);}}
.ai-messages{height:220px;overflow-y:auto;padding:14px;display:flex;flex-direction:column;gap:10px;}
.ai-msg{max-width:88%;}
.ai-msg.user{align-self:flex-end;}
.ai-msg.assistant{align-self:flex-start;}
.ai-bubble{padding:9px 13px;border-radius:10px;font-size:0.8rem;line-height:1.6;}
.ai-msg.user .ai-bubble{background:var(--grad2);color:white;border-radius:10px 10px 2px 10px;}
.ai-msg.assistant .ai-bubble{background:var(--surface2);border:1px solid var(--border2);border-radius:10px 10px 10px 2px;}
.ai-input-row{display:flex;gap:7px;padding:10px 14px;border-top:1px solid var(--border);}
.ai-input{flex:1;background:var(--bg3);border:1px solid var(--border2);border-radius:7px;color:var(--text);font-size:0.8rem;padding:8px 11px;outline:none;font-family:var(--font);}
.ai-input:focus{border-color:var(--brand-primary);}
.ai-send{background:var(--grad2);border:none;border-radius:7px;color:white;padding:8px 12px;cursor:pointer;transition:var(--trans);display:flex;align-items:center;}
.ai-send:hover{transform:scale(1.05);}
.ai-typing{display:flex;gap:3px;padding:9px 13px;}
.ai-dot{width:5px;height:5px;border-radius:50%;background:var(--muted);animation:typingDot 1.2s infinite;}
.ai-dot:nth-child(2){animation-delay:0.2s;}
.ai-dot:nth-child(3){animation-delay:0.4s;}
@keyframes typingDot{0%,60%,100%{transform:translateY(0);opacity:0.4;}30%{transform:translateY(-5px);opacity:1;}}

/* ── EMPTY STATE ── */
.empty-state{text-align:center;padding:48px 20px;color:var(--muted);}
.empty-state svg{margin-bottom:14px;opacity:0.3;}
.empty-state h3{font-size:0.95rem;color:var(--text2);margin-bottom:5px;}
.empty-state p{font-size:0.8rem;}

/* ── SECTION TAG ── */
.section-tag{display:inline-block;padding:5px 14px;border-radius:50px;background:rgba(124,110,247,0.08);border:1px solid rgba(124,110,247,0.2);color:var(--brand-secondary);font-size:0.66rem;font-weight:700;text-transform:uppercase;letter-spacing:0.1em;margin-bottom:12px;}

/* ── ANIMATIONS ── */
@keyframes fadeIn{from{opacity:0;transform:translateY(10px);}to{opacity:1;transform:translateY(0);}}
@keyframes slideIn{from{opacity:0;transform:translateX(20px);}to{opacity:1;transform:translateX(0);}}
.animate-fade{animation:fadeIn 0.35s ease forwards;}
.animate-slide{animation:slideIn 0.3s ease forwards;}

/* ── MESSAGE ── */
.msg-item{display:flex;align-items:flex-start;gap:12px;padding:14px 18px;cursor:pointer;transition:var(--trans);border-bottom:1px solid var(--border);}
.msg-item:hover{background:var(--surface2);}
.msg-item.unread{border-left:3px solid var(--brand-primary);}
.msg-item.selected{background:rgba(124,110,247,0.05);}

/* ══════════════════════════════════════════════════════════════
   MOBILE RESPONSIVE — Comprehensive
══════════════════════════════════════════════════════════════ */

/* Tablet */
@media(max-width:1024px){
  .grid-4{grid-template-columns:repeat(2,1fr);}
  .grid-3{grid-template-columns:repeat(2,1fr);}
  .main-content{padding:20px 24px;}
}

/* Mobile — full layout change */
@media(max-width:768px){
  /* Hide sidebar, show hamburger */
  .sidebar{
    position:fixed;
    left:-240px;
    top:0;
    height:100vh;
    z-index:200;
    box-shadow:8px 0 32px rgba(0,0,0,0.5);
  }
  .sidebar.open{left:0;}
  .sidebar-overlay{display:block;opacity:0;pointer-events:none;transition:opacity 0.3s;}
  .sidebar-overlay.show{opacity:1;pointer-events:all;}
  .mobile-menu-btn{display:flex;}

  /* Mobile top bar */
  .mobile-topbar{
    display:flex;
    align-items:center;
    justify-content:space-between;
    padding:12px 16px;
    background:var(--bg2);
    border-bottom:1px solid var(--border);
    position:sticky;
    top:0;
    z-index:150;
  }
  .mobile-topbar-logo{font-size:0.9rem;font-weight:800;background:var(--grad2);-webkit-background-clip:text;-webkit-text-fill-color:transparent;}

  /* Main content full width */
  .layout{display:block;}
  .main-content{padding:16px;}

  /* Grids */
  .grid-2,.grid-3,.grid-4{grid-template-columns:1fr;}
  .stats-grid{grid-template-columns:1fr 1fr;}

  /* Flex wrapping */
  .flex-between{flex-wrap:wrap;gap:8px;}

  /* Tabs */
  .tab-bar{width:100%;overflow-x:auto;}

  /* Tables */
  th,td{padding:8px 10px;font-size:0.76rem;}

  /* Modals */
  .modal{padding:20px 16px;border-radius:var(--rl);}

  /* Cards */
  .card{padding:14px;}

  /* Navbar */
  .navbar{padding:0 16px;}
  .nav-links a:not(.btn){display:none;}

  /* Two-pane layouts */
  .two-pane{flex-direction:column!important;}
  .track-pane{width:100%!important;}

  /* Module headers */
  .module-header>div:nth-child(3){flex-wrap:wrap;gap:4px;}

  /* Buttons in module header */
  .module-header .btn{font-size:0.7rem;padding:4px 8px;}

  /* Stat cards 2 col on mobile */
  .stats-grid{grid-template-columns:1fr 1fr;gap:10px;}
  .stat-value{font-size:1.4rem;}

  /* Welcome banner */
  .welcome-banner{flex-direction:column;align-items:flex-start;gap:10px;padding:16px;}

  /* Quick actions 2x2 */
  .quick-actions-grid{grid-template-columns:1fr 1fr!important;}

  /* AI box */
  .ai-messages{height:180px;}

  /* Toast */
  .toast-container{left:16px;right:16px;max-width:none;}
}

@media(max-width:480px){
  .stats-grid{grid-template-columns:1fr 1fr;}
  .main-content{padding:12px;}
  h1{font-size:1.2rem!important;}
  .btn-lg{padding:10px 18px;font-size:0.84rem;}
  .modal{max-height:95vh;}

  /* Hide less important table columns on very small screens */
  .hide-xs{display:none!important;}
}