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

:root {
  --bg-deep: hsl(240, 25%, 7%);
  --bg-space: hsl(240, 22%, 10%);
  --card-glass: hsla(240, 20%, 15%, 0.6);
  --border-glass: hsla(240, 15%, 25%, 0.5);
  
  --accent-indigo: hsl(250, 85%, 65%);
  --accent-indigo-glow: hsla(250, 85%, 65%, 0.3);
  --accent-purple: hsl(270, 85%, 60%);
  --accent-purple-glow: hsla(270, 85%, 60%, 0.3);
  
  --color-success: hsl(160, 85%, 45%);
  --color-success-glow: hsla(160, 85%, 45%, 0.2);
  --color-warning: hsl(38, 92%, 56%);
  --color-warning-glow: hsla(38, 92%, 56%, 0.2);
  --color-danger: hsl(0, 84%, 60%);
  
  --text-primary: hsl(210, 40%, 98%);
  --text-muted: hsl(215, 20%, 65%);
  --text-dim: hsl(215, 12%, 45%);
  
  --sidebar-width: 280px;
  --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
  font-family: 'Outfit', sans-serif;
  background-color: var(--bg-deep);
  background-image: 
    radial-gradient(at 0% 0%, hsla(253, 50%, 12%, 0.8) 0px, transparent 50%),
    radial-gradient(at 100% 100%, hsla(280, 40%, 10%, 0.7) 0px, transparent 50%);
  color: var(--text-primary);
  height: 100vh;
  overflow: hidden;
  display: flex;
}

/* Sidebar Styling */
.sidebar {
  width: var(--sidebar-width);
  height: 100%;
  background: var(--card-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-right: 1px solid var(--border-glass);
  padding: 2rem 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  z-index: 100;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 2.5rem;
}

.brand-logo {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--accent-indigo), var(--accent-purple));
  border-radius: 12px;
  box-shadow: 0 0 15px var(--accent-indigo-glow);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
}

.brand-name {
  font-weight: 800;
  font-size: 1.25rem;
  background: linear-gradient(to right, #f8fafc, #a855f7);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  letter-spacing: 0.5px;
}

/* User Progress Card */
.user-card {
  background: hsla(240, 20%, 8%, 0.6);
  border: 1px solid var(--border-glass);
  border-radius: 16px;
  padding: 1.25rem;
  margin-bottom: 2rem;
}

.user-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

.user-avatar {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: linear-gradient(to bottom right, #a855f7, #6366f1);
  border: 2px solid var(--border-glass);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
}

.user-meta .username {
  font-weight: 600;
  font-size: 0.95rem;
}

.user-meta .rank {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.user-stats {
  display: flex;
  justify-content: space-between;
  gap: 0.5rem;
  margin-top: 1rem;
}

.stat-box {
  flex: 1;
  text-align: center;
  background: hsla(240, 20%, 15%, 0.4);
  border-radius: 8px;
  padding: 0.5rem;
}

.stat-val {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--color-warning);
}

.stat-lbl {
  font-size: 0.65rem;
  text-transform: uppercase;
  color: var(--text-muted);
  letter-spacing: 0.5px;
  margin-top: 2px;
}

/* Sidebar Navigation */
.nav-menu {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  flex-grow: 1;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.85rem 1.25rem;
  border-radius: 12px;
  color: var(--text-muted);
  font-weight: 500;
  text-decoration: none;
  cursor: pointer;
  transition: var(--transition-smooth);
}

.nav-item:hover {
  background: hsla(240, 20%, 20%, 0.4);
  color: var(--text-primary);
}

.nav-item.active {
  background: linear-gradient(135deg, var(--accent-indigo), var(--accent-purple));
  color: #fff;
  box-shadow: 0 4px 15px hsla(250, 85%, 65%, 0.25);
}

.sidebar-footer {
  font-size: 0.75rem;
  color: var(--text-dim);
  text-align: center;
  border-top: 1px solid var(--border-glass);
  padding-top: 1rem;
}

/* Main Content Area */
.main-content {
  flex-grow: 1;
  height: 100%;
  display: flex;
  flex-direction: column;
  padding: 2rem;
  overflow-y: auto;
}

.tab-pane {
  display: none;
  flex-direction: column;
  gap: 1.5rem;
  animation: fadeIn 0.4s ease-out;
}

.tab-pane.active {
  display: flex;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Glass Card Grid */
.glass-card {
  background: var(--card-glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-glass);
  border-radius: 20px;
  padding: 1.75rem;
  box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.3);
}

.header-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
}

.title-group h2 {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.5px;
}

.title-group p {
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* Dashboard View Styles */
.dashboard-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 1.5rem;
}

.stats-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
}

.metric-card {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.metric-num {
  font-size: 2.25rem;
  font-weight: 800;
  background: linear-gradient(to right, #fff, var(--accent-indigo));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.badge-rack {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-top: 1rem;
}

.badge-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background: hsla(240, 20%, 8%, 0.6);
  border: 1px solid var(--border-glass);
  border-radius: 10px;
  padding: 0.5rem 0.75rem;
  font-size: 0.85rem;
  transition: var(--transition-smooth);
}

.badge-item.locked {
  opacity: 0.4;
  filter: grayscale(1);
}

.badge-item:not(.locked) {
  box-shadow: 0 0 10px var(--accent-indigo-glow);
  border-color: var(--accent-indigo);
}

.badge-icon {
  font-size: 1.2rem;
}

/* Interactive Dials & Graphs */
.dial-container {
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
  width: 180px;
  height: 180px;
  margin: 1.5rem auto;
}

.dial-svg {
  transform: rotate(-90deg);
  width: 100%;
  height: 100%;
}

.dial-bg {
  fill: none;
  stroke: var(--bg-deep);
  stroke-width: 12;
}

.dial-fill {
  fill: none;
  stroke: url(#dial-grad);
  stroke-width: 12;
  stroke-dasharray: 440;
  stroke-dashoffset: 440;
  transition: stroke-dashoffset 1s ease-out;
  stroke-linecap: round;
}

.dial-text {
  position: absolute;
  text-align: center;
  display: flex;
  flex-direction: column;
}

.dial-score {
  font-size: 2.25rem;
  font-weight: 800;
}

.dial-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
}

/* Risk indicator */
.risk-indicator {
  padding: 0.5rem 1rem;
  border-radius: 20px;
  font-weight: 700;
  font-size: 0.85rem;
  text-align: center;
  margin: 1rem auto;
  max-width: 120px;
}

.risk-low { background: var(--color-success-glow); color: var(--color-success); border: 1px solid var(--color-success); }
.risk-med { background: var(--color-warning-glow); color: var(--color-warning); border: 1px solid var(--color-warning); }
.risk-high { background: rgba(239, 68, 68, 0.2); color: var(--color-danger); border: 1px solid var(--color-danger); }

/* DSA Page Styling */
.dsa-layout {
  display: grid;
  grid-template-columns: 2.2fr 1fr;
  gap: 1.5rem;
}

.canvas-container {
  background: hsla(240, 20%, 8%, 0.8);
  border: 1px solid var(--border-glass);
  border-radius: 16px;
  overflow: hidden;
  position: relative;
  min-height: 480px;
}

canvas {
  display: block;
}

.dsa-controls {
  display: flex;
  gap: 0.75rem;
  background: var(--card-glass);
  padding: 0.75rem;
  border-radius: 12px;
  position: absolute;
  top: 15px;
  left: 15px;
  border: 1px solid var(--border-glass);
  z-index: 10;
}

.dsa-sidebar {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.dsa-panel {
  background: var(--card-glass);
  border: 1px solid var(--border-glass);
  border-radius: 16px;
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.terminal-log {
  background: #09090e;
  border: 1px solid var(--border-glass);
  border-radius: 12px;
  padding: 1rem;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
  height: 200px;
  overflow-y: auto;
  color: #c9d1d9;
}

.log-item {
  margin-bottom: 0.5rem;
  line-height: 1.4;
}

.log-time {
  color: var(--accent-indigo);
}

/* Inputs & Form Controls */
.input-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

label {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-muted);
}

select, input[type="text"], textarea {
  background: hsla(240, 20%, 8%, 0.6);
  border: 1px solid var(--border-glass);
  color: var(--text-primary);
  padding: 0.75rem 1rem;
  border-radius: 10px;
  font-family: inherit;
  font-size: 0.9rem;
  transition: var(--transition-smooth);
}

select:focus, input[type="text"]:focus, textarea:focus {
  border-color: var(--accent-indigo);
  outline: none;
  box-shadow: 0 0 10px var(--accent-indigo-glow);
}

/* Sliders */
.slider-container {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  margin-bottom: 0.85rem;
}

.slider-labels {
  display: flex;
  justify-content: space-between;
  font-size: 0.85rem;
}

.slider-val {
  font-weight: 700;
  color: var(--accent-indigo);
}

input[type="range"] {
  -webkit-appearance: none;
  width: 100%;
  height: 6px;
  background: var(--bg-deep);
  border-radius: 3px;
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent-indigo);
  cursor: pointer;
  box-shadow: 0 0 8px var(--accent-indigo-glow);
  transition: var(--transition-smooth);
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.2);
}

/* Buttons */
.btn {
  background: var(--accent-indigo);
  color: #fff;
  border: none;
  padding: 0.75rem 1.25rem;
  border-radius: 10px;
  font-family: inherit;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition-smooth);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}

.btn:hover {
  background: var(--accent-purple);
  box-shadow: 0 4px 15px var(--accent-purple-glow);
}

.btn-secondary {
  background: hsla(240, 20%, 8%, 0.6);
  border: 1px solid var(--border-glass);
  color: var(--text-primary);
}

.btn-secondary:hover {
  background: hsla(240, 20%, 15%, 0.8);
  border-color: var(--accent-indigo);
}

.btn-sm {
  padding: 0.5rem 0.85rem;
  font-size: 0.8rem;
  border-radius: 8px;
}

/* DSA Table */
.dsa-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.dsa-table th, .dsa-table td {
  padding: 0.5rem;
  text-align: left;
  border-bottom: 1px solid var(--border-glass);
}

.dsa-table th {
  font-weight: 600;
  color: var(--text-primary);
}

.highlighted-dist {
  color: var(--color-warning);
  font-weight: 700;
}

.status-indicator {
  font-size: 0.7rem;
  background: hsla(240, 15%, 15%, 0.6);
  padding: 2px 6px;
  border-radius: 4px;
}

.status-indicator.final {
  background: var(--color-success-glow);
  color: var(--color-success);
}

/* Tree Component Visuals */
.tree-container {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  background: hsla(240, 20%, 8%, 0.6);
  border: 1px solid var(--border-glass);
  border-radius: 12px;
  padding: 1.25rem;
  max-height: 350px;
  overflow-y: auto;
}

.tree-node {
  margin-left: 1.25rem;
  border-left: 1px dotted var(--border-glass);
  padding-left: 0.75rem;
  margin-top: 0.4rem;
}

.tree-node-header {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  padding: 4px 8px;
  border-radius: 6px;
  transition: var(--transition-smooth);
}

.tree-node-header:hover {
  background: hsla(240, 20%, 20%, 0.4);
}

.tree-node-name {
  font-weight: 500;
  font-size: 0.9rem;
}

.tree-node-detail {
  font-size: 0.75rem;
  color: var(--text-dim);
}

.tree-children {
  transition: max-height 0.3s ease-in-out;
  overflow: hidden;
  max-height: 500px;
}

.tree-children.collapsed {
  max-height: 0;
}

/* ML View Styles */
.ml-dashboard {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: 1.5rem;
}

.ml-metrics-panel {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.weights-grid {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  background: hsla(240, 20%, 8%, 0.5);
  border-radius: 10px;
  padding: 0.75rem;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem;
}

.weight-row {
  display: flex;
  justify-content: space-between;
}

.weight-val {
  color: var(--accent-purple);
}

/* AI Tutor Chat Styling */
.chat-container {
  display: flex;
  flex-direction: column;
  height: 480px;
  border: 1px solid var(--border-glass);
  border-radius: 16px;
  background: hsla(240, 20%, 8%, 0.6);
  overflow: hidden;
}

.chat-messages {
  flex-grow: 1;
  padding: 1.25rem;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.message {
  display: flex;
  gap: 0.75rem;
  max-width: 80%;
  animation: messageSlide 0.3s ease-out;
}

@keyframes messageSlide {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.message.user {
  align-self: flex-end;
  flex-direction: row-reverse;
}

.message-avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  flex-shrink: 0;
}

.message.tutor .message-avatar {
  background: linear-gradient(135deg, var(--accent-indigo), var(--accent-purple));
}

.message.user .message-avatar {
  background: #475569;
}

.message-bubble {
  background: var(--card-glass);
  border: 1px solid var(--border-glass);
  padding: 0.85rem 1.25rem;
  border-radius: 16px;
  font-size: 0.9rem;
  line-height: 1.5;
}

.message.user .message-bubble {
  background: var(--accent-indigo);
  border-color: var(--accent-indigo);
  color: #fff;
  border-top-right-radius: 2px;
}

.message.tutor .message-bubble {
  border-top-left-radius: 2px;
}

.message-bubble h3 {
  font-size: 1.05rem;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.message-bubble ul, .message-bubble ol {
  margin-left: 1.25rem;
  margin-bottom: 0.5rem;
}

.message-bubble li {
  margin-bottom: 0.25rem;
}

.message-bubble blockquote {
  border-left: 3px solid var(--accent-indigo);
  padding-left: 0.75rem;
  color: var(--text-muted);
  font-style: italic;
  margin: 0.75rem 0;
}

.code-box {
  background: #09090e;
  border-radius: 8px;
  padding: 0.75rem;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
  margin: 0.75rem 0;
  border: 1px solid var(--border-glass);
  white-space: pre-wrap;
}

.chat-input-bar {
  display: flex;
  gap: 0.75rem;
  padding: 1rem;
  background: var(--card-glass);
  border-top: 1px solid var(--border-glass);
}

.chat-input-bar input {
  flex-grow: 1;
}

/* Quiz UI Components */
.quiz-panel {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.quiz-card {
  background: hsla(240, 20%, 8%, 0.6);
  border: 1px solid var(--border-glass);
  border-radius: 12px;
  padding: 1.25rem;
  margin-bottom: 1rem;
}

.quiz-question {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.option-btn {
  background: hsla(240, 15%, 15%, 0.6);
  border: 1px solid var(--border-glass);
  color: var(--text-primary);
  text-align: left;
  padding: 0.75rem 1rem;
  border-radius: 8px;
  cursor: pointer;
  font-family: inherit;
  font-size: 0.85rem;
  transition: var(--transition-smooth);
}

.option-btn:hover {
  background: hsla(240, 20%, 20%, 0.8);
  border-color: var(--accent-indigo);
}

.option-btn.selected {
  background: var(--accent-indigo-glow);
  border-color: var(--accent-indigo);
}

.option-btn.correct {
  background: var(--color-success-glow);
  border-color: var(--color-success);
  color: var(--color-success);
}

.option-btn.incorrect {
  background: rgba(239, 68, 68, 0.15);
  border-color: var(--color-danger);
  color: var(--color-danger);
}

/* RAG Simulator Page */
.rag-grid {
  display: grid;
  grid-template-columns: 1.5fr 1.2fr;
  gap: 1.5rem;
}

.pipeline-diagram {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-top: 1rem;
}

.pipeline-step {
  display: flex;
  align-items: center;
  gap: 1rem;
  background: hsla(240, 20%, 8%, 0.6);
  border: 1px solid var(--border-glass);
  border-radius: 10px;
  padding: 0.75rem 1rem;
  font-size: 0.85rem;
  transition: var(--transition-smooth);
}

.pipeline-step.active {
  border-color: var(--color-warning);
  box-shadow: 0 0 10px var(--color-warning-glow);
}

.step-num {
  width: 24px;
  height: 24px;
  background: var(--accent-purple);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.75rem;
}

.pipeline-step.active .step-num {
  background: var(--color-warning);
}

/* Summary Revision Cards */
.summary-container {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.revision-card {
  perspective: 1000px;
  width: 100%;
  height: 120px;
  cursor: pointer;
}

.revision-card-inner {
  position: relative;
  width: 100%;
  height: 100%;
  text-align: center;
  transition: transform 0.6s;
  transform-style: preserve-3d;
}

.revision-card.flipped .revision-card-inner {
  transform: rotateY(180deg);
}

.revision-card-front, .revision-card-back {
  position: absolute;
  width: 100%;
  height: 100%;
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
  border-radius: 12px;
  border: 1px solid var(--border-glass);
  padding: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.revision-card-front {
  background: linear-gradient(135deg, var(--card-glass), hsla(250, 20%, 20%, 0.4));
  color: var(--accent-indigo);
  font-weight: 700;
  font-size: 1.1rem;
}

.revision-card-back {
  background: hsla(240, 20%, 8%, 0.9);
  color: var(--text-primary);
  transform: rotateY(180deg);
  font-size: 0.85rem;
  line-height: 1.4;
}

/* Language selector */
.lang-selector {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

.lang-btn {
  background: hsla(240, 15%, 15%, 0.6);
  border: 1px solid var(--border-glass);
  color: var(--text-muted);
  border-radius: 8px;
  padding: 0.4rem 0.80rem;
  font-size: 0.8rem;
  font-family: inherit;
  cursor: pointer;
  transition: var(--transition-smooth);
}

.lang-btn.active {
  background: var(--accent-purple-glow);
  border-color: var(--accent-purple);
  color: var(--text-primary);
}

/* Scrollbar customization */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: var(--bg-deep);
}

::-webkit-scrollbar-thumb {
  background: var(--border-glass);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent-indigo);
}