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

:root {
  --bg: #0A0E1A;
  --bg2: #0f1529;
  --card: rgba(15,21,41,0.85);
  --teal: #00D4AA;
  --gold: #F5A623;
  --blue: #3B6EF5;
  --text: #E8EEFF;
  --text2: rgba(232,238,255,0.6);
  --border: rgba(0,212,170,0.15);
  --success: #00D4AA;
  --danger: #FF4D6A;
  --warn: #F5A623;
  --sidebar-w: 280px;
  --hdr: 70px;
  --radius: 16px;
  --glass: blur(18px);
  --shadow: 0 8px 32px rgba(0,0,0,0.5);
  --glow-teal: 0 0 25px rgba(0,212,170,0.3);
  --glow-gold: 0 0 25px rgba(245,166,35,0.3);
  --grad-teal: linear-gradient(135deg,#00D4AA,#0096FF);
  --grad-gold: linear-gradient(135deg,#F5A623,#FF6B35);
  --grad-mixed: linear-gradient(135deg,#00D4AA,#3B6EF5,#F5A623);
}

[data-theme="light"] {
  --bg: #F0F4FF;
  --bg2: #E8EEFF;
  --card: rgba(255,255,255,0.95);
  --text: #0A0E1A;
  --text2: rgba(10,14,26,0.62);
  --border: rgba(0,212,170,0.25);
  --shadow: 0 8px 32px rgba(0,0,0,0.10);
  --glow-teal: 0 0 20px rgba(0,212,170,0.18);
}
[data-theme="light"] body::before {
  background:
    radial-gradient(ellipse 60% 50% at 15% 40%, rgba(0,212,170,.06) 0%, transparent 70%),
    radial-gradient(ellipse 50% 60% at 85% 20%, rgba(59,110,245,.07) 0%, transparent 70%);
}
[data-theme="light"] .header { background: rgba(240,244,255,0.93); border-bottom-color: rgba(0,212,170,.2); }
[data-theme="light"] .nav-links { background: rgba(0,0,0,.04); }
[data-theme="light"] .nav-links a { color: rgba(10,14,26,.6); }
[data-theme="light"] .nav-links a:hover { color: #0A0E1A; background: rgba(0,212,170,.1); }
[data-theme="light"] .sidebar { background: rgba(232,238,255,0.98); border-right-color: rgba(0,212,170,.2); }
[data-theme="light"] .sidebar-title { color: #007a60; }
[data-theme="light"] .sidebar-search input { background: rgba(0,0,0,.06); color: #0A0E1A; border-color: rgba(0,212,170,.2); }
[data-theme="light"] .sidebar-section-title { color: #9a6200; }
[data-theme="light"] .lesson-list li { color: rgba(10,14,26,.6); }
[data-theme="light"] .lesson-list li:hover { background: rgba(0,212,170,.07); color: #0A0E1A; }
[data-theme="light"] .lesson-list li.active { color: #007a60; background: linear-gradient(90deg,rgba(0,212,170,.12),transparent); }
[data-theme="light"] .modal-content { background: #ecf0fc; }
[data-theme="light"] .modal-header { background: rgba(0,212,170,.06); }
[data-theme="light"] .input-field { background: rgba(0,0,0,.05); color: #0A0E1A; border-color: rgba(0,212,170,.25); }
[data-theme="light"] .auth-modal .modal-overlay { background: rgba(0,0,0,.4); }
[data-theme="light"] .chat-box { background: rgba(240,244,255,0.99); border-color: rgba(0,212,170,.2); }
[data-theme="light"] .chat-header { background: rgba(0,212,170,.06); border-bottom-color: rgba(0,212,170,.15); }
[data-theme="light"] .chat-input-area { background: rgba(0,0,0,.03); }
[data-theme="light"] #chat-input { background: rgba(0,0,0,.05); color: #0A0E1A; border-color: rgba(0,212,170,.2); }
[data-theme="light"] .message.ai { background: rgba(0,212,170,.07); border-color: rgba(0,212,170,.15); color: #0A0E1A; }
[data-theme="light"] .feature-card { background: rgba(255,255,255,.9); }
[data-theme="light"] .feature-card p { color: rgba(10,14,26,.6); }
[data-theme="light"] .daily-challenge { background: rgba(255,255,255,.95); }
[data-theme="light"] .stat-box { background: rgba(0,0,0,.05); }
[data-theme="light"] .stat-label { color: rgba(10,14,26,.55); }
[data-theme="light"] .xp-bar-wrap { background: rgba(0,0,0,.08); }
[data-theme="light"] .heatmap-cell { background: rgba(0,0,0,.07); }
[data-theme="light"] .lb-row { background: rgba(255,255,255,.9); }
[data-theme="light"] .badge-front, [data-theme="light"] .badge-back { background: rgba(0,0,0,.04); }
[data-theme="light"] .bottom-nav { background: rgba(232,238,255,.97); border-top-color: rgba(0,212,170,.2); }
[data-theme="light"] .bottom-nav-item { color: rgba(10,14,26,.55); }
[data-theme="light"] .bottom-nav-item.active { color: #007a60; }
[data-theme="light"] .toast { background: rgba(240,244,255,.99); }
[data-theme="light"] .roadmap-card { background: rgba(255,255,255,.9); }
[data-theme="light"] .submission-table th { background: rgba(0,0,0,.04); color: rgba(10,14,26,.6); }
[data-theme="light"] .submission-table td { border-bottom-color: rgba(0,0,0,.06); }
[data-theme="light"] .teacher-stat { background: rgba(255,255,255,.9); }
[data-theme="light"] .course-info p { color: rgba(10,14,26,.6); }
/* Smooth theme transitions */
body, .header, .sidebar, .chat-box, .modal-content, .feature-card,
.course-card, .profile-card, .achievements, .stat-box, .lb-row,
.toast, .bottom-nav, .lesson-list li, .nav-links, .nav-links a,
.input-field, #chat-input, .message, .daily-challenge {
  transition: background .3s ease, color .3s ease, border-color .3s ease;
}


*{box-sizing:border-box;margin:0;padding:0;scroll-behavior:smooth}

@media (prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Nunito', sans-serif;
  overflow-x: hidden;
  transition: background .3s, color .3s;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 60% 50% at 15% 40%, rgba(0,212,170,.08) 0%, transparent 70%),
    radial-gradient(ellipse 50% 60% at 85% 20%, rgba(59,110,245,.1) 0%, transparent 70%),
    radial-gradient(ellipse 40% 40% at 50% 80%, rgba(245,166,35,.05) 0%, transparent 70%);
  pointer-events: none;
  z-index: 0;
}

/* ── HEADER ── */
.header {
  height: var(--hdr);
  background: rgba(10,14,26,.8);
  backdrop-filter: var(--glass);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 32px;
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
}

.logo a {
  font-family:'Space Mono',monospace;
  font-size: 1.5rem;
  font-weight: 700;
  background: var(--grad-teal);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 10px;
}
.logo i { -webkit-text-fill-color: initial; color: var(--teal); }

/* Pill Navigation */
.nav-links {
  display: flex;
  gap: 6px;
  align-items: center;
  background: rgba(255,255,255,.04);
  padding: 6px;
  border-radius: 50px;
  border: 1px solid var(--border);
}
.nav-links a {
  color: var(--text2);
  text-decoration: none;
  font-weight: 600;
  font-size: .92rem;
  padding: 7px 16px;
  border-radius: 50px;
  display: flex;
  align-items: center;
  gap: 7px;
  transition: all .3s;
  position: relative;
}
.nav-links a:hover { color: var(--text); background: rgba(0,212,170,.1); }
.nav-links a.active {
  background: var(--grad-teal);
  color: #0A0E1A;
  font-weight: 700;
  box-shadow: var(--glow-teal);
}

.controls { display:flex; align-items:center; gap:12px; }

/* ── BUTTONS ── */
.btn {
  padding: 10px 22px;
  border-radius: 50px;
  border: none;
  font-weight: 700;
  cursor: pointer;
  transition: all .3s;
  font-size: .95rem;
  font-family: 'Nunito', sans-serif;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
}
.btn.primary {
  background: var(--grad-teal);
  color: #0A0E1A;
  box-shadow: var(--glow-teal);
}
.btn.primary:hover { transform: translateY(-2px) scale(1.03); filter: brightness(1.1); }
.btn.secondary {
  background: var(--grad-gold);
  color: #0A0E1A;
  box-shadow: var(--glow-gold);
}
.btn.outline {
  background: transparent;
  border: 1.5px solid var(--border);
  color: var(--text);
}
.btn.outline:hover { border-color: var(--teal); background: rgba(0,212,170,.08); }
.btn.success { background: linear-gradient(135deg,#00D4AA,#00b894); color:#0A0E1A; }
.btn.danger { background: linear-gradient(135deg,#FF4D6A,#c0392b); color:white; }
.btn.icon-btn {
  padding: 10px;
  border-radius: 50%;
  background: rgba(255,255,255,.06);
  color: var(--text);
  border: 1px solid var(--border);
}
.btn.icon-btn:hover { background: var(--teal); color:#0A0E1A; }

/* ── PAGE ── */
.page-container {
  margin-top: var(--hdr);
  min-height: calc(100vh - var(--hdr));
  padding: 40px;
  animation: fadeUp .5s ease-out;
  position: relative;
  z-index: 1;
}
@keyframes fadeUp {
  from { opacity:0; transform:translateY(24px); }
  to   { opacity:1; transform:translateY(0); }
}

/* ── HERO ── */
.hero {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 85vh;
  padding: 0 4%;
  position: relative;
  overflow: hidden;
}

/* Kazakh ornament SVG background */
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%2300D4AA' fill-opacity='0.04'%3E%3Cpath d='M30 0 L35 10 L45 10 L38 16 L41 27 L30 21 L19 27 L22 16 L15 10 L25 10Z'/%3E%3Cpath d='M0 30 L10 25 L10 35 L0 30Z M60 30 L50 25 L50 35 L60 30Z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  opacity: 1;
  pointer-events: none;
}

/* Animated blob */
.hero-blob {
  position: absolute;
  top: 10%;
  right: 5%;
  width: 500px;
  height: 500px;
  border-radius: 50%;
  background: conic-gradient(from 0deg, rgba(0,212,170,.15), rgba(59,110,245,.15), rgba(245,166,35,.1), rgba(0,212,170,.15));
  filter: blur(60px);
  animation: blobSpin 12s linear infinite;
  pointer-events: none;
}
@keyframes blobSpin {
  0%   { transform: scale(1) rotate(0deg); }
  50%  { transform: scale(1.15) rotate(180deg); }
  100% { transform: scale(1) rotate(360deg); }
}

.hero-content { flex:1; max-width:600px; z-index:2; }
.hero h1 {
  font-family: 'Space Mono', monospace;
  font-size: 3.4rem;
  line-height: 1.1;
  margin-bottom: 20px;
  font-weight: 700;
}
.hero h1 .accent {
  background: var(--grad-teal);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero p { font-size: 1.15rem; color: var(--text2); margin-bottom: 36px; line-height: 1.7; }
.hero-buttons { display:flex; gap:14px; flex-wrap:wrap; }

.hero-visual { flex:1; display:flex; justify-content:center; align-items:center; z-index:2; }

/* Typewriter code card */
.code-card {
  background: rgba(5,8,18,.9);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 28px 32px;
  box-shadow: var(--shadow), var(--glow-teal);
  width: 100%;
  max-width: 460px;
  animation: float 6s ease-in-out infinite;
  position: relative;
  overflow: hidden;
}
.code-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: var(--grad-teal);
}
.code-card-dots { display:flex; gap:8px; margin-bottom:18px; }
.code-card-dots span {
  width:12px; height:12px; border-radius:50%;
}
.code-card-dots span:nth-child(1) { background:#FF4D6A; }
.code-card-dots span:nth-child(2) { background:#F5A623; }
.code-card-dots span:nth-child(3) { background:#00D4AA; }
.code-card pre {
  font-family:'Space Mono',monospace;
  font-size:.95rem;
  color:#a8b2d1;
  line-height:1.7;
}
.k { color:#c678dd; } .fn { color:#61afef; }
.s { color:#98c379; } .cm { color:#5c6370; font-style:italic; }
.n { color:#e06c75; }

@keyframes float {
  0%,100% { transform: translateY(0) rotate(0deg); }
  50%      { transform: translateY(-18px) rotate(.5deg); }
}

/* Typewriter cursor */
.cursor {
  display: inline-block;
  width: 2px;
  height: 1em;
  background: var(--teal);
  animation: blink .7s step-end infinite;
  vertical-align: text-bottom;
  margin-left: 2px;
}
@keyframes blink { 50% { opacity:0; } }

/* ── FEATURES ── */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  margin-top: 80px;
}
.feature-card {
  background: var(--card);
  backdrop-filter: var(--glass);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  text-align: center;
  transition: transform .3s, box-shadow .3s;
  position: relative;
  overflow: hidden;
}
.feature-card::before {
  content: '';
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 3px;
  background: var(--grad-teal);
  transform: scaleX(0);
  transition: transform .3s;
}
.feature-card:hover::before { transform: scaleX(1); }
.feature-card:hover { transform: translateY(-8px); box-shadow: var(--glow-teal); }
.feature-icon { font-size:2.8rem; color:var(--teal); margin-bottom:18px; }
.feature-card h3 { font-family:'Space Mono',monospace; font-size:1.2rem; margin-bottom:12px; }
.feature-card p { color:var(--text2); line-height:1.6; }

/* Daily challenge */
.daily-challenge {
  background: var(--card);
  border: 1px solid var(--gold);
  border-radius: var(--radius);
  padding: 32px;
  margin-top: 60px;
  display: flex;
  gap: 32px;
  align-items: center;
  box-shadow: var(--glow-gold);
}
.daily-challenge .dc-icon { font-size:3.5rem; }
.daily-challenge h3 { font-family:'Space Mono',monospace; color:var(--gold); margin-bottom:8px; }
.daily-challenge p { color:var(--text2); margin-bottom:16px; }
.dc-timer { font-family:'Space Mono',monospace; font-size:1.1rem; color:var(--teal); }

/* ── LAYOUT (lesson) ── */
.layout {
  display: flex;
  margin-top: var(--hdr);
  height: calc(100vh - var(--hdr));
  position: relative;
  z-index: 1;
}

/* ── SIDEBAR ── */
.sidebar {
  width: var(--sidebar-w);
  background: rgba(8,12,28,.95);
  border-right: 1px solid var(--border);
  height: 100%;
  overflow-y: auto;
  flex-shrink: 0;
  transition: transform .3s;
}
.sidebar::-webkit-scrollbar { width:4px; }
.sidebar::-webkit-scrollbar-thumb { background:var(--border); border-radius:4px; }
.sidebar-title {
  padding: 20px 24px 16px;
  font-family:'Space Mono',monospace;
  font-size:.95rem;
  font-weight:700;
  color:var(--teal);
  border-bottom: 1px solid var(--border);
  display:flex;
  align-items:center;
  gap:8px;
}
.sidebar-search {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
}
.sidebar-search input {
  width: 100%;
  background: rgba(255,255,255,.05);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px 12px;
  color: var(--text);
  font-size: .9rem;
  font-family:'Nunito',sans-serif;
  outline:none;
}
.sidebar-search input:focus { border-color: var(--teal); }

.lesson-list { list-style:none; padding: 8px 0; }
.lesson-list li {
  padding: 12px 24px;
  cursor: pointer;
  font-size: .92rem;
  display: flex;
  align-items: center;
  gap: 10px;
  transition: all .25s;
  border-left: 3px solid transparent;
  color: var(--text2);
}
.lesson-list li:hover { background: rgba(0,212,170,.06); color:var(--text); border-left-color: rgba(0,212,170,.4); }
.lesson-list li.active {
  background: linear-gradient(90deg, rgba(0,212,170,.15), transparent);
  border-left-color: var(--teal);
  color: var(--teal);
  font-weight: 700;
}
.lesson-list li .lesson-status { margin-left:auto; font-size:.85rem; }
.lesson-list li.done { opacity:.7; }
.lesson-list li.locked { opacity:.45; cursor:not-allowed; }

/* Section collapse */
.sidebar-section-title {
  padding: 10px 24px 4px;
  font-size:.75rem;
  font-weight:700;
  text-transform:uppercase;
  letter-spacing:1px;
  color: var(--gold);
  cursor: pointer;
  display:flex;
  align-items:center;
  gap:6px;
}
.sidebar-section-title .arrow { transition: transform .3s; }
.sidebar-section.collapsed .sidebar-section-title .arrow { transform: rotate(-90deg); }
.sidebar-section.collapsed .lesson-list { display:none; }

/* ── MAIN CONTENT ── */
.main-content {
  flex:1;
  display:flex;
  flex-direction:column;
  padding: 24px 32px;
  overflow-y: auto;
  gap: 24px;
}
.lesson-content {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px;
  transition: opacity .2s;
}
.lesson-content h1 {
  font-family:'Space Mono',monospace;
  font-size:2rem;
  margin-bottom:20px;
  background: var(--grad-teal);
  -webkit-background-clip:text;
  -webkit-text-fill-color:transparent;
}
.lesson-content p, .lesson-content ul, .lesson-content ol {
  font-size:1.05rem; line-height:1.8; color:var(--text2); margin-bottom:16px;
}
[data-theme="light"] .lesson-content p,
[data-theme="light"] .lesson-content ul { color: rgba(10,14,26,.75); }
.lesson-content code {
  background:rgba(0,212,170,.1);
  padding:2px 8px;
  border-radius:6px;
  font-family:'Space Mono',monospace;
  font-size:.88em;
  color:var(--teal);
}
.lesson-content ul li { margin-bottom: 8px; }

/* Lesson inner boxes */
.lesson-theory {
  background: rgba(0,212,170,.06);
  border-left: 4px solid var(--teal);
  padding: 18px 20px;
  border-radius:0 12px 12px 0;
  margin:20px 0;
}
.lesson-theory h4 { color:var(--teal); font-size:1.05rem; margin-bottom:10px; display:flex;align-items:center;gap:8px; }
.lesson-example {
  background: rgba(245,166,35,.06);
  border: 1px solid rgba(245,166,35,.2);
  padding: 18px 20px;
  border-radius:12px;
  margin:20px 0;
}
.lesson-example h4 { color:var(--gold); margin-bottom:10px; }

/* Task box */
.task-box-styled {
  background: rgba(0,212,170,.08);
  border: 2px dashed rgba(0,212,170,.3);
  padding:18px 20px;
  border-radius:12px;
  margin:20px 0;
}
.task-box-styled strong { color:var(--teal); }

/* Video */
.video-wrapper {
  position:relative; padding-bottom:56.25%; height:0; overflow:hidden;
  border-radius:12px; margin:20px 0; border:1px solid var(--border);
}
.video-wrapper iframe { position:absolute;top:0;left:0;width:100%;height:100%;border-radius:12px; }

/* ── EDITOR ── */
.editor-section {
  display:flex;
  flex-direction:column;
  background: #000;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  overflow:hidden;
  min-height:420px;
  box-shadow: var(--shadow), var(--glow-teal);
  flex-shrink: 0;
}
.editor-header {
  display:flex;
  justify-content:space-between;
  align-items:center;
  padding: 12px 20px;
  background: #0d1117;
  border-bottom: 1px solid rgba(255,255,255,.08);
}
.editor-header span { font-family:'Space Mono',monospace; font-size:.85rem; color:var(--teal); display:flex;align-items:center;gap:8px; }
.editor-header .controls { gap:8px; }
#code-editor {
  flex:1; min-height:220px; padding:20px;
  background:#000; color:#abb2bf;
  font-family:'Space Mono',monospace; font-size:1rem;
  border:none; resize:none; outline:none; line-height:1.6;
}

/* Session Timer */
.session-timer {
  padding: 6px 14px;
  background: rgba(0,212,170,.08);
  border-radius:20px;
  font-family:'Space Mono',monospace;
  font-size:.8rem;
  color:var(--teal);
  display:flex;align-items:center;gap:6px;
}

/* Output console */
.output-header {
  padding:8px 20px;
  background:#0d1117;
  color:var(--text2);
  border-top:1px solid rgba(255,255,255,.06);
  font-family:'Space Mono',monospace;
  font-size:.78rem;
  text-transform:uppercase;
  letter-spacing:1px;
  display:flex;align-items:center;gap:8px;
}
#output {
  padding:16px 20px;
  height:160px;
  background:#020408;
  font-family:'Space Mono',monospace;
  white-space:pre-wrap;
  overflow-y:auto;
  font-size:.93rem;
  line-height:1.6;
}
#output::-webkit-scrollbar { width:4px; }
#output::-webkit-scrollbar-thumb { background:rgba(255,255,255,.1); border-radius:4px; }
.out-stdout { color:#abb2bf; }
.out-error { color:#FF4D6A; font-weight:bold; }
.out-warn { color:#F5A623; }
.out-success { color:#00D4AA; font-weight:bold; }

/* ── COURSES ── */
.courses-container { max-width:1200px; margin:0 auto; }
.course-header { text-align:center; margin-bottom:48px; }
.course-header h1 { font-family:'Space Mono',monospace; font-size:2.8rem; margin-bottom:10px; }
.course-header p { color:var(--text2); font-size:1.1rem; }
.course-grid { display:grid; grid-template-columns:repeat(auto-fill,minmax(320px,1fr)); gap:28px; }

.course-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow:hidden;
  transition: transform .35s, box-shadow .35s;
  cursor:pointer;
  position:relative;
}
.course-card:hover { transform: translateY(-8px) scale(1.02); box-shadow: var(--glow-teal); }
.course-card::after {
  content:'';
  position:absolute;
  top:0;left:0;
  width:4px;height:100%;
  background:var(--grad-teal);
}
.course-card:nth-child(2)::after { background:var(--grad-gold); }
.course-card:nth-child(3)::after { background:linear-gradient(135deg,#a855f7,#ec4899); }

.course-img {
  height:160px;
  background:var(--grad-teal);
  display:flex;justify-content:center;align-items:center;
  font-size:4rem;color:rgba(255,255,255,.9);
  position:relative;overflow:hidden;
}
.course-img::after {
  content:'';position:absolute;inset:0;
  background:rgba(0,0,0,.15);
}
.course-info { padding:24px; }
.course-info h3 { font-family:'Space Mono',monospace; font-size:1.25rem; margin-bottom:8px; }
.course-info p { color:var(--text2); font-size:.95rem; margin-bottom:16px; line-height:1.5; }
[data-theme="light"] .course-info p { color:rgba(10,14,26,.6); }

/* Difficulty badge */
.diff-badge {
  display:inline-flex;align-items:center;gap:5px;
  padding:3px 10px;border-radius:20px;
  font-size:.78rem;font-weight:700;
  margin-bottom:12px;
}
.diff-easy { background:rgba(0,212,170,.15); color:var(--teal); border:1px solid rgba(0,212,170,.3); }
.diff-mid  { background:rgba(245,166,35,.15); color:var(--gold);  border:1px solid rgba(245,166,35,.3); }
.diff-hard { background:rgba(255,77,106,.15); color:#FF4D6A; border:1px solid rgba(255,77,106,.3); }

/* SVG Progress Ring */
.progress-ring-wrap { display:flex;align-items:center;gap:16px;margin-bottom:16px; }
.progress-ring { transform:rotate(-90deg); }
.progress-ring-bg { fill:none; stroke:rgba(255,255,255,.08); stroke-width:4; }
.progress-ring-fill { fill:none; stroke:var(--teal); stroke-width:4; stroke-linecap:round; transition:stroke-dashoffset 1s ease; }
.ring-label { font-family:'Space Mono',monospace; font-size:.85rem; color:var(--teal); }

/* ── PROFILE ── */
.profile-container { max-width:1000px;margin:0 auto;display:grid;grid-template-columns:300px 1fr;gap:32px; }

.profile-card {
  background:var(--card);border:1px solid var(--border);
  border-radius:var(--radius);padding:32px;text-align:center;
}
/* Gradient rank border on avatar */
.avatar-wrap {
  width:130px;height:130px;border-radius:50%;
  background:var(--grad-teal);
  padding:3px;margin:0 auto 16px;
  animation:borderSpin 4s linear infinite;
}
@keyframes borderSpin {
  0%  { background-image:linear-gradient(0deg,#00D4AA,#F5A623,#3B6EF5); }
  100%{ background-image:linear-gradient(360deg,#00D4AA,#F5A623,#3B6EF5); }
}
.avatar {
  width:100%;height:100%;border-radius:50%;
  background:var(--bg2);display:flex;align-items:center;justify-content:center;
  font-size:3.2rem;color:var(--teal);
}

.profile-name { font-family:'Space Mono',monospace;font-size:1.6rem;margin-bottom:6px; }
.level-badge {
  display:inline-block;padding:3px 14px;border-radius:20px;
  font-size:.8rem;font-weight:700;background:var(--gold);color:#0A0E1A;margin-bottom:6px;
}
.profile-rank { color:var(--text2);font-size:.9rem;margin-bottom:20px; }

/* Animated XP bar */
.xp-bar-wrap { width:100%;background:rgba(255,255,255,.07);border-radius:10px;height:18px;margin-bottom:8px;overflow:hidden; }
.xp-bar {
  height:100%;background:var(--grad-teal);border-radius:10px;
  width:0%;transition:width 1.5s cubic-bezier(.25,.46,.45,.94);
  display:flex;align-items:center;justify-content:flex-end;padding-right:8px;
  font-size:.7rem;font-weight:700;color:#0A0E1A;
}
.xp-next { font-size:.78rem;color:var(--text2);text-align:right;margin-bottom:20px; }

.stats-grid { display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-top:20px; }
.stat-box { background:rgba(255,255,255,.04);padding:16px;border-radius:12px;border:1px solid var(--border); }
.stat-num { font-family:'Space Mono',monospace;font-size:1.8rem;font-weight:700;color:var(--teal); }
.stat-label { font-size:.82rem;color:var(--text2);margin-top:4px; }

/* Achievements */
.achievements { background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:32px; }
.achievements h2 { font-family:'Space Mono',monospace;font-size:1.4rem;margin-bottom:6px; }
.badge-grid { display:flex;flex-wrap:wrap;gap:16px;margin-top:20px; }

/* 3D Flip Badge */
.badge-wrap { width:100px;height:110px;perspective:600px;cursor:pointer; }
.badge-inner {
  position:relative;width:100%;height:100%;
  transform-style:preserve-3d;transition:transform .6s;
}
.badge-wrap:hover .badge-inner { transform:rotateY(180deg); }
.badge-front,.badge-back {
  position:absolute;inset:0;backface-visibility:hidden;
  background:rgba(255,255,255,.05);border:1px solid var(--border);
  border-radius:14px;padding:12px;display:flex;
  flex-direction:column;align-items:center;justify-content:center;
  text-align:center;
}
.badge-back { transform:rotateY(180deg);background:rgba(0,212,170,.1);border-color:var(--teal); }
.badge-front i { font-size:2.2rem;margin-bottom:8px;color:var(--gold); }
.badge-front span { font-size:.72rem;font-weight:700; }
.badge-back p { font-size:.7rem;color:var(--teal);line-height:1.4; }
.badge-wrap.locked .badge-front { opacity:.3;filter:grayscale(1); }

/* Streak Heatmap */
.heatmap { margin-top:24px; }
.heatmap h3 { font-family:'Space Mono',monospace;font-size:1rem;margin-bottom:14px;color:var(--teal); }
.heatmap-grid { display:flex;flex-wrap:wrap;gap:4px; }
.heatmap-cell {
  width:16px;height:16px;border-radius:3px;
  background:rgba(255,255,255,.05);
  transition:transform .2s;cursor:default;
}
.heatmap-cell:hover { transform:scale(1.3); }
.heatmap-cell.level-1 { background:rgba(0,212,170,.2); }
.heatmap-cell.level-2 { background:rgba(0,212,170,.45); }
.heatmap-cell.level-3 { background:rgba(0,212,170,.7); }
.heatmap-cell.level-4 { background:#00D4AA; }

/* ── LEADERBOARD ── */
.leaderboard-list { display:flex;flex-direction:column;gap:10px; }
.lb-row {
  display:flex;justify-content:space-between;align-items:center;
  padding:14px 20px;border-radius:14px;
  background:rgba(255,255,255,.04);border:1px solid var(--border);
  animation:slideIn .4s ease-out both;
}
@keyframes slideIn {
  from{opacity:0;transform:translateX(-20px);}
  to{opacity:1;transform:translateX(0);}
}
.lb-row.me { background:rgba(0,212,170,.1);border-color:var(--teal); }
.lb-row.gold   { border-color:gold; }
.lb-row.silver { border-color:silver; }
.lb-row.bronze { border-color:#cd7f32; }
.lb-avatar {
  width:38px;height:38px;border-radius:50%;
  display:flex;align-items:center;justify-content:center;
  font-weight:800;font-size:1rem;color:#0A0E1A;
}

/* ── AI CHAT ── */
.chat-widget { position:fixed;bottom:24px;right:24px;z-index:9999; }
.chat-toggle-btn {
  width:64px;height:64px;border-radius:50%;
  background:var(--grad-teal);color:#0A0E1A;
  border:none;font-size:1.8rem;cursor:pointer;
  box-shadow:0 8px 24px rgba(0,212,170,.5);
  transition:all .3s;display:flex;align-items:center;justify-content:center;
  position:relative;
}
.chat-toggle-btn::after {
  content:'';position:absolute;inset:0;border-radius:50%;
  background:inherit;z-index:-1;animation:chatPulse 2.5s infinite;
}
@keyframes chatPulse {
  0%{transform:scale(1);opacity:.7;}
  100%{transform:scale(1.6);opacity:0;}
}
.chat-toggle-btn:hover { transform:scale(1.1) rotate(10deg); }

.chat-box {
  position:absolute;bottom:80px;right:0;
  width:390px;height:540px;
  background:rgba(8,12,28,.97);
  backdrop-filter:var(--glass);
  border:1px solid var(--border);
  border-radius:24px;
  box-shadow:var(--shadow),var(--glow-teal);
  display:flex;flex-direction:column;overflow:hidden;
  transition:opacity .4s,transform .4s cubic-bezier(.175,.885,.32,1.275);
  transform-origin:bottom right;
}
.chat-box.closed { opacity:0;transform:scale(.3) translateY(80px);pointer-events:none; }

.chat-header {
  padding:16px 20px;
  background:rgba(0,212,170,.08);
  border-bottom:1px solid var(--border);
  display:flex;justify-content:space-between;align-items:center;
  font-family:'Space Mono',monospace;font-size:1rem;font-weight:700;
  color:var(--teal);
}
.chat-header-left { display:flex;align-items:center;gap:10px; }
.chat-header-actions { display:flex;gap:6px; }

.chat-messages {
  flex:1;padding:16px;overflow-y:auto;
  display:flex;flex-direction:column;gap:12px;
  scroll-behavior:smooth;
}
.chat-messages::-webkit-scrollbar { width:3px; }
.chat-messages::-webkit-scrollbar-thumb { background:var(--border);border-radius:3px; }

.message {
  max-width:82%;padding:12px 16px;border-radius:18px;
  font-size:.95rem;line-height:1.5;animation:msgIn .3s ease-out;
}
@keyframes msgIn {
  from{opacity:0;transform:translateY(10px) scale(.95);}
  to{opacity:1;transform:translateY(0) scale(1);}
}
.message.ai {
  background:rgba(0,212,170,.1);color:var(--text);
  align-self:flex-start;border:1px solid rgba(0,212,170,.2);
  border-bottom-left-radius:4px;
}
.message.user {
  background:var(--grad-teal);color:#0A0E1A;
  align-self:flex-end;border-bottom-right-radius:4px;font-weight:600;
}
/* Typing indicator */
.typing-dots { display:flex;gap:4px;align-items:center; }
.typing-dots span {
  width:7px;height:7px;border-radius:50%;background:var(--teal);
  animation:dot .8s ease-in-out infinite;
}
.typing-dots span:nth-child(2){animation-delay:.15s;}
.typing-dots span:nth-child(3){animation-delay:.3s;}
@keyframes dot {
  0%,80%,100%{transform:scale(.6);opacity:.4;}
  40%{transform:scale(1);opacity:1;}
}
/* Markdown in chat */
.message.ai code {
  background:rgba(0,0,0,.4);padding:2px 6px;border-radius:4px;
  font-family:'Space Mono',monospace;font-size:.85em;color:var(--teal);
}
.message.ai pre {
  background:rgba(0,0,0,.5);padding:10px;border-radius:8px;
  font-family:'Space Mono',monospace;font-size:.82em;
  overflow-x:auto;margin:8px 0;border:1px solid var(--border);
  position:relative;
}
.insert-code-btn {
  display:block;margin-top:6px;
  font-size:.75rem;cursor:pointer;
  background:rgba(0,212,170,.15);
  color:var(--teal);border:1px solid rgba(0,212,170,.3);
  border-radius:6px;padding:3px 8px;
  font-family:'Nunito',sans-serif;
}

.chat-input-area {
  padding:14px 16px;
  border-top:1px solid var(--border);
  display:flex;gap:10px;background:rgba(0,0,0,.2);
}
#chat-input {
  flex:1;padding:12px 18px;border:1px solid var(--border);
  border-radius:24px;outline:none;
  background:rgba(255,255,255,.05);color:var(--text);
  font-size:.95rem;font-family:'Nunito',sans-serif;transition:all .3s;
}
#chat-input:focus { border-color:var(--teal);box-shadow:0 0 8px rgba(0,212,170,.2); }
.chat-send-row { display:flex;gap:8px;align-items:center; }
#chat-send,#voice-btn {
  width:46px;height:46px;border-radius:50%;border:none;
  cursor:pointer;display:flex;align-items:center;justify-content:center;
  font-size:1.1rem;transition:transform .2s;
}
#chat-send { background:var(--grad-teal);color:#0A0E1A; }
#voice-btn { background:rgba(245,166,35,.15);color:var(--gold);border:1px solid rgba(245,166,35,.3); }
#chat-send:hover,#voice-btn:hover { transform:scale(1.1); }

/* ── TEACHER ── */
.teacher-stats { display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:16px;margin-bottom:28px; }
.teacher-stat { background:var(--card);border:1px solid var(--border);border-radius:14px;padding:20px;text-align:center; }
.teacher-stat .num { font-family:'Space Mono',monospace;font-size:2rem;font-weight:700;color:var(--gold); }
.teacher-stat .lbl { color:var(--text2);font-size:.85rem; }

.submission-table { width:100%;border-collapse:collapse;min-width:700px; }
.submission-table th { padding:12px 16px;background:rgba(255,255,255,.04);text-align:left;font-size:.85rem;color:var(--text2);border-bottom:2px solid var(--border); }
.submission-table td { padding:12px 16px;border-bottom:1px solid rgba(255,255,255,.04);font-size:.9rem; }
.submission-table tr:hover td { background:rgba(0,212,170,.03); }

.status-badge {
  display:inline-flex;align-items:center;gap:5px;
  padding:3px 10px;border-radius:20px;font-size:.78rem;font-weight:700;
}
.status-pending { background:rgba(245,166,35,.15);color:var(--gold);border:1px solid rgba(245,166,35,.3); }
.status-accepted{ background:rgba(0,212,170,.15);color:var(--teal);border:1px solid rgba(0,212,170,.3); }
.status-rejected{ background:rgba(255,77,106,.15);color:#FF4D6A;border:1px solid rgba(255,77,106,.3); }

/* ── MODALS ── */
.modal-overlay {
  position:fixed;inset:0;background:rgba(0,0,0,.7);
  backdrop-filter:blur(10px);display:flex;
  align-items:center;justify-content:center;z-index:10000;
  opacity:1;transition:opacity .3s;
}
.modal-overlay.hidden { opacity:0;pointer-events:none; }
.modal-content {
  background:var(--bg2);border:1px solid var(--border);
  border-radius:24px;width:90%;max-width:420px;
  box-shadow:var(--shadow),var(--glow-teal);
  transform:scale(1);transition:transform .3s cubic-bezier(.175,.885,.32,1.275);overflow:hidden;
}
.modal-overlay.hidden .modal-content { transform:scale(.8); }
.modal-header {
  padding:20px 24px;background:rgba(0,212,170,.06);
  border-bottom:1px solid var(--border);
  display:flex;justify-content:space-between;align-items:center;
}
.modal-body { padding:24px; }
.input-field {
  padding:13px 16px;border-radius:12px;border:1px solid var(--border);
  background:rgba(255,255,255,.05);color:var(--text);
  font-size:1rem;font-family:'Nunito',sans-serif;outline:none;transition:border-color .3s;
  width:100%;
}
.input-field:focus { border-color:var(--teal);box-shadow:0 0 8px rgba(0,212,170,.2); }

/* Level-up modal */
.levelup-modal .modal-content { text-align:center;padding:40px; }
.levelup-modal .level-emoji { font-size:5rem;margin-bottom:16px; }
.levelup-modal h2 { font-family:'Space Mono',monospace;font-size:1.8rem;color:var(--gold);margin-bottom:8px; }
.levelup-modal p { color:var(--text2); }

/* Toast notification */
.toast-container { position:fixed;bottom:24px;left:24px;z-index:9998;display:flex;flex-direction:column;gap:10px; }
.toast {
  background:rgba(8,12,28,.97);border:1px solid var(--border);
  border-radius:14px;padding:14px 20px;
  display:flex;align-items:center;gap:14px;
  box-shadow:var(--shadow);min-width:280px;max-width:360px;
  animation:toastIn .4s ease-out;
}
@keyframes toastIn {
  from{opacity:0;transform:translateX(-40px);}
  to{opacity:1;transform:translateX(0);}
}
.toast.hide { animation:toastOut .3s ease-in forwards; }
@keyframes toastOut {
  to{opacity:0;transform:translateX(-60px);}
}
.toast-icon { font-size:1.8rem; }
.toast-msg { flex:1; }
.toast-msg strong { display:block;font-size:.95rem;margin-bottom:2px; }
.toast-msg span { font-size:.82rem;color:var(--text2); }
.toast-success { border-left:4px solid var(--teal); }
.toast-badge { border-left:4px solid var(--gold); }
.toast-level { border-left:4px solid #a855f7; }

/* User badge in header */
.user-badge {
  display:flex;align-items:center;gap:8px;
  background:rgba(0,212,170,.1);padding:6px 16px;border-radius:50px;
  border:1px solid rgba(0,212,170,.3);font-weight:700;cursor:pointer;
  font-size:.9rem;transition:all .3s;
}
.user-badge:hover { background:rgba(0,212,170,.2); }
.user-badge i { color:var(--teal); }

/* Focus mode */
body.focus-mode .header { display:none; }
body.focus-mode .chat-widget { display:none; }
body.focus-mode .layout { margin-top:0;height:100vh; }

/* Roadmap */
.roadmap-container { max-width:800px;margin:0 auto;position:relative; }
.roadmap-line { width:4px;background:linear-gradient(180deg,var(--teal),var(--gold),#a855f7);position:absolute;left:50%;transform:translateX(-50%);top:0;bottom:0;border-radius:4px; }
.roadmap-node {
  display:flex;gap:24px;margin-bottom:40px;align-items:flex-start;
  position:relative;
}
.roadmap-node:nth-child(even) { flex-direction:row-reverse; }
.roadmap-dot {
  min-width:20px;height:20px;border-radius:50%;background:var(--teal);
  position:absolute;left:50%;transform:translateX(-50%);
  box-shadow:0 0 12px rgba(0,212,170,.5);z-index:2;
}
.roadmap-dot.locked { background:rgba(255,255,255,.2);box-shadow:none; }
.roadmap-dot.current { animation:nodePulse 1.5s ease-in-out infinite; }
@keyframes nodePulse {
  0%,100%{box-shadow:0 0 12px rgba(0,212,170,.5);}
  50%{box-shadow:0 0 28px rgba(0,212,170,.9);}
}
.roadmap-card {
  background:var(--card);border:1px solid var(--border);border-radius:14px;
  padding:20px;flex:1;max-width:calc(50% - 30px);
  transition:transform .3s;
}
.roadmap-card:hover { transform:translateY(-4px); }
.roadmap-card.locked { opacity:.45; }
.roadmap-card.done { border-color:var(--teal); }
.roadmap-card.current { border-color:var(--gold);box-shadow:var(--glow-gold); }

/* Theory page */
.theory-layout { display:flex;gap:32px;max-width:1100px;margin:0 auto; }
.theory-toc {
  width:220px;flex-shrink:0;
  background:var(--card);border:1px solid var(--border);
  border-radius:var(--radius);padding:20px;
  position:sticky;top:calc(var(--hdr)+20px);height:fit-content;
  max-height:calc(100vh - var(--hdr) - 40px);overflow-y:auto;
}
.theory-toc h3 { font-family:'Space Mono',monospace;font-size:.85rem;color:var(--teal);margin-bottom:16px; }
.toc-link { display:block;font-size:.88rem;color:var(--text2);text-decoration:none;padding:5px 0;transition:color .2s;border-left:2px solid transparent;padding-left:10px; }
.toc-link.active,.toc-link:hover { color:var(--teal);border-left-color:var(--teal); }
.theory-content { flex:1;background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:40px; }
.theory-content h2 { font-family:'Space Mono',monospace;font-size:1.5rem;color:var(--teal);margin:32px 0 12px;scroll-margin-top:100px; }
.theory-content p { color:var(--text2);line-height:1.8;margin-bottom:16px; }
.hljs-block {
  background:#0d1117;border-radius:12px;padding:20px;
  margin:16px 0;border:1px solid var(--border);position:relative;
}
.copy-btn {
  position:absolute;top:10px;right:10px;
  background:rgba(0,212,170,.1);border:1px solid rgba(0,212,170,.3);
  color:var(--teal);border-radius:6px;padding:4px 10px;
  font-size:.75rem;cursor:pointer;font-family:'Nunito',sans-serif;
  transition:all .2s;
}
.copy-btn:hover { background:rgba(0,212,170,.2); }

/* Mini-games */
.minigame-card { background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:32px;margin-bottom:24px; }
.minigame-card h3 { font-family:'Space Mono',monospace;color:var(--gold);margin-bottom:16px; }
.fill-blank { font-family:'Space Mono',monospace;font-size:1rem;line-height:2; }
.blank-input {
  border:none;border-bottom:2px solid var(--teal);background:transparent;
  color:var(--teal);width:100px;font-family:'Space Mono',monospace;
  font-size:1rem;outline:none;text-align:center;
}
.drag-item {
  background:rgba(0,212,170,.1);border:1px solid rgba(0,212,170,.3);
  border-radius:8px;padding:8px 14px;cursor:grab;
  font-family:'Space Mono',monospace;font-size:.9rem;margin:4px;
  display:inline-block;user-select:none;
}
.drag-item.dragging { opacity:.4;cursor:grabbing; }
.drop-zone {
  min-height:100px;border:2px dashed var(--border);border-radius:12px;
  padding:10px;margin-top:16px;transition:border-color .2s;
}
.drop-zone.over { border-color:var(--teal);background:rgba(0,212,170,.04); }

/* PWA install btn */
#pwa-install-btn {
  position:fixed;bottom:100px;left:24px;
  background:var(--grad-gold);color:#0A0E1A;
  border:none;border-radius:50px;padding:12px 20px;
  font-weight:700;cursor:pointer;font-family:'Nunito',sans-serif;
  box-shadow:var(--glow-gold);animation:fadeUp .5s ease-out;
  display:flex;align-items:center;gap:8px;z-index:1000;
}

/* Mobile bottom nav */
.bottom-nav {
  display:none;position:fixed;bottom:0;left:0;right:0;
  background:rgba(8,12,28,.97);border-top:1px solid var(--border);
  padding:10px 0 env(safe-area-inset-bottom);
  z-index:900;
}
.bottom-nav-inner { display:flex;justify-content:space-around; }
.bottom-nav-item {
  display:flex;flex-direction:column;align-items:center;gap:4px;
  color:var(--text2);text-decoration:none;font-size:.72rem;font-weight:600;
  padding:4px 12px;border-radius:10px;transition:all .2s;
}
.bottom-nav-item i { font-size:1.3rem; }
.bottom-nav-item.active { color:var(--teal); }

/* Responsive */
@media (max-width:1024px) {
  .profile-container { grid-template-columns:1fr; }
  .hero h1 { font-size:2.6rem; }
  .theory-layout { flex-direction:column; }
  .theory-toc { width:100%;position:static;max-height:none; }
}
@media (max-width:768px) {
  .header { padding:0 16px; }
  .nav-links { display:none; }
  .bottom-nav { display:flex; }
  .hero { flex-direction:column;text-align:center;padding-top:40px;min-height:auto;padding-bottom:40px; }
  .hero-visual { display:none; }
  .page-container { padding:20px; margin-bottom:70px; }
  .layout { flex-direction:column; height:auto; margin-bottom:70px; }
  .sidebar {
    width:100%;height:auto;border-right:none;border-bottom:1px solid var(--border);
    position:fixed;top:var(--hdr);left:0;z-index:500;
    transform:translateX(-100%);height:calc(100vh - var(--hdr));
    transition:transform .3s;
  }
  .sidebar.open { transform:translateX(0); }
  .main-content { padding:16px; }
  .chat-box { width:calc(100vw - 32px);height:80vh;right:-8px;bottom:80px; }
  .roadmap-node { flex-direction:column!important;align-items:center; }
  .roadmap-line { left:24px; }
  .roadmap-dot { left:24px; }
  .roadmap-card { max-width:100%; }
  .course-grid { grid-template-columns:1fr; }
  .profile-container { grid-template-columns:1fr; }
  .teacher-stats { grid-template-columns:1fr 1fr; }
  #pwa-install-btn { bottom:80px; }
}