/* ==========================================================================
   LINUX-LEARN DESIGN SYSTEM (style.css)
   A premium cyberpunk-themed aesthetic with modern CSS features,
   glassmorphism, interactive layouts, and dynamic typography.
   ========================================================================== */

/* 1. Base Variables & Themes */
:root {
  /* Color Palettes per Theme (HSL) */
  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --font-display: 'Outfit', sans-serif;
  --font-mono: 'Fira Code', 'JetBrains Mono', monospace;

  /* Classic Matrix Green (Default) */
  --hue-green: 145;
  --color-primary-green: hsl(var(--hue-green), 100%, 54%);
  --color-primary-glow-green: hsla(var(--hue-green), 100%, 54%, 0.35);
  --color-bg-dark-green: hsl(var(--hue-green), 30%, 4%);
  --color-bg-panel-green: hsla(var(--hue-green), 20%, 8%, 0.75);

  /* Digital Neon Cyan */
  --hue-cyan: 190;
  --color-primary-cyan: hsl(var(--hue-cyan), 100%, 50%);
  --color-primary-glow-cyan: hsla(var(--hue-cyan), 100%, 50%, 0.35);
  --color-bg-dark-cyan: hsl(var(--hue-cyan), 30%, 4%);
  --color-bg-panel-cyan: hsla(var(--hue-cyan), 20%, 8%, 0.75);

  /* Retro Amber */
  --hue-amber: 38;
  --color-primary-amber: hsl(var(--hue-amber), 100%, 50%);
  --color-primary-glow-amber: hsla(var(--hue-amber), 100%, 50%, 0.35);
  --color-bg-dark-amber: hsl(var(--hue-amber), 20%, 4%);
  --color-bg-panel-amber: hsla(var(--hue-amber), 15%, 8%, 0.75);

  /* Cyber Synthwave Pink */
  --hue-pink: 320;
  --color-primary-pink: hsl(var(--hue-pink), 100%, 60%);
  --color-primary-glow-pink: hsla(var(--hue-pink), 100%, 60%, 0.35);
  --color-bg-dark-pink: hsl(var(--hue-pink), 25%, 4%);
  --color-bg-panel-pink: hsla(var(--hue-pink), 15%, 8%, 0.75);

  /* Shared Semantic Colors */
  --color-bg-darker: #07090e;
  --color-border: rgba(255, 255, 255, 0.08);
  --color-border-hover: rgba(255, 255, 255, 0.16);
  --color-text-white: #ffffff;
  --color-text-muted: #8892b0;
  
  --shadow-premium: 0 20px 40px -15px rgba(0, 0, 0, 0.7);
  --transition-smooth: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  --transition-fast: all 0.15s ease-out;
}

/* Active Theme Setup (applied to body) */
body.theme-green {
  --color-theme: var(--color-primary-green);
  --color-theme-glow: var(--color-primary-glow-green);
  --color-bg: var(--color-bg-dark-green);
  --color-panel: var(--color-bg-panel-green);
  --theme-gradient: linear-gradient(135deg, hsl(145, 100%, 50%), hsl(160, 100%, 40%));
}

body.theme-cyan {
  --color-theme: var(--color-primary-cyan);
  --color-theme-glow: var(--color-primary-glow-cyan);
  --color-bg: var(--color-bg-dark-cyan);
  --color-panel: var(--color-bg-panel-cyan);
  --theme-gradient: linear-gradient(135deg, hsl(190, 100%, 50%), hsl(210, 100%, 50%));
}

body.theme-amber {
  --color-theme: var(--color-primary-amber);
  --color-theme-glow: var(--color-primary-glow-amber);
  --color-bg: var(--color-bg-dark-amber);
  --color-panel: var(--color-bg-panel-amber);
  --theme-gradient: linear-gradient(135deg, hsl(38, 100%, 50%), hsl(22, 100%, 50%));
}

body.theme-pink {
  --color-theme: var(--color-primary-pink);
  --color-theme-glow: var(--color-primary-glow-pink);
  --color-bg: var(--color-bg-dark-pink);
  --color-panel: var(--color-bg-panel-pink);
  --theme-gradient: linear-gradient(135deg, hsl(320, 100%, 60%), hsl(280, 100%, 50%));
}

/* 2. Global Resets & HTML */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-family: var(--font-sans);
  color: var(--color-text-white);
  background-color: var(--color-bg-darker);
  overflow: hidden;
  height: 100%;
  scrollbar-gutter: stable;
}

body {
  position: relative;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background-color: var(--color-bg);
  transition: background-color 0.6s ease;
}

/* 3. Special Visual FX (CRT, Scanlines, Glow Orbs) */
#matrix-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
  opacity: 0.12;
  transition: opacity 0.3s ease;
}

.glow-orb {
  position: fixed;
  border-radius: 50%;
  filter: blur(120px);
  z-index: 0;
  pointer-events: none;
  opacity: 0.25;
  mix-blend-mode: screen;
  transition: background 0.6s ease;
}

.orb-1 {
  top: -10%;
  right: 15%;
  width: 50vw;
  height: 50vh;
  background: var(--theme-gradient);
  animation: floatOrb1 15s infinite alternate ease-in-out;
}

.orb-2 {
  bottom: -10%;
  left: 10%;
  width: 45vw;
  height: 45vh;
  background: var(--color-theme-glow);
  animation: floatOrb2 18s infinite alternate ease-in-out;
}

@keyframes floatOrb1 {
  0% { transform: translateY(0) scale(1); }
  100% { transform: translateY(40px) scale(1.1); }
}
@keyframes floatOrb2 {
  0% { transform: translateY(0) scale(1.1); }
  100% { transform: translateY(-30px) scale(0.9); }
}

/* CRT Screen Effect overlay */
.crt-overlay {
  display: block;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    rgba(18, 16, 16, 0) 50%, 
    rgba(0, 0, 0, 0.25) 50%
  ), linear-gradient(
    90deg,
    rgba(255, 0, 0, 0.04),
    rgba(0, 255, 0, 0.01),
    rgba(0, 0, 255, 0.04)
  );
  background-size: 100% 4px, 6px 100%;
  z-index: 9999;
  pointer-events: none;
  opacity: 0.45;
  transition: opacity 0.3s ease;
}

body.scanlines-active::after {
  content: " ";
  display: block;
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
  background: rgba(18, 16, 16, 0.06);
  opacity: 0;
  z-index: 10000;
  pointer-events: none;
  animation: crtFlicker 0.15s infinite;
}

@keyframes crtFlicker {
  0% { opacity: 0.452; }
  50% { opacity: 0.485; }
  100% { opacity: 0.441; }
}

.text-glow {
  text-shadow: 0 0 10px var(--color-theme-glow);
}

.badge-glow {
  box-shadow: 0 0 15px var(--color-theme-glow);
  border: 1px solid var(--color-theme) !important;
}

/* Screen reader class */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

/* 4. Main App Layout */
.app-container {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  height: 100vh;
  max-width: 1600px;
  margin: 0 auto;
  padding: 1.5rem;
  overflow: hidden;
}

/* Header Component */
.app-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.25rem;
  padding: 0.75rem 1.5rem;
  background: var(--color-panel);
  border: 1px solid var(--color-border);
  border-radius: 16px;
  backdrop-filter: blur(16px);
  box-shadow: var(--shadow-premium);
}

.header-brand {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.penguin-logo {
  font-size: 2.25rem;
  filter: drop-shadow(0 0 8px var(--color-theme-glow));
  animation: pulseLogo 3s infinite alternate ease-in-out;
}

@keyframes pulseLogo {
  0% { transform: scale(1) rotate(0deg); }
  50% { transform: scale(1.05) rotate(3deg); }
  100% { transform: scale(1) rotate(-3deg); }
}

.brand-text h1 {
  font-family: var(--font-display);
  font-size: 1.75rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  background: var(--theme-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.brand-tagline {
  font-size: 0.75rem;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 1.5px;
  font-weight: 600;
}

.dashboard-stats {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.stat-item {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
}

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

.stat-value {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--color-theme);
}

/* 5. Workspace Area Grid */
.app-workspace {
  display: grid;
  grid-template-columns: 400px 1fr;
  gap: 1.25rem;
  flex: 1;
  min-height: 0; /* Important for grid item content overflow */
  margin-bottom: 0.75rem;
}

@media (max-width: 1024px) {
  .app-workspace {
    grid-template-columns: 1fr;
    grid-template-rows: 1fr 1.2fr;
    overflow-y: auto;
  }
}

/* Workspace Sidebar Panels */
.workspace-sidebar {
  display: flex;
  flex-direction: column;
  background: var(--color-panel);
  border: 1px solid var(--color-border);
  border-radius: 20px;
  backdrop-filter: blur(16px);
  box-shadow: var(--shadow-premium);
  overflow: hidden;
}

.sidebar-tabs {
  display: flex;
  background: rgba(0, 0, 0, 0.2);
  border-bottom: 1px solid var(--color-border);
  padding: 0.5rem 0.75rem 0;
  gap: 0.25rem;
}

.tab-btn {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1rem;
  background: transparent;
  border: 1px solid transparent;
  border-bottom: none;
  border-radius: 12px 12px 0 0;
  color: var(--color-text-muted);
  font-family: var(--font-display);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition-fast);
}

.tab-btn:hover {
  color: var(--color-text-white);
  background: rgba(255, 255, 255, 0.03);
}

.tab-btn.active {
  color: var(--color-theme);
  background: var(--color-bg-darker);
  border-color: var(--color-border);
  font-weight: 600;
  box-shadow: inset 0 2px 0 0 var(--color-theme);
}

.tab-icon {
  opacity: 0.7;
}
.tab-btn.active .tab-icon {
  opacity: 1;
  filter: drop-shadow(0 0 4px var(--color-theme-glow));
}

.sidebar-content-wrapper {
  flex: 1;
  overflow: hidden;
  position: relative;
}

.sidebar-panel {
  display: flex;
  flex-direction: column;
  height: 100%;
  padding: 1.25rem;
  overflow-y: auto;
  scrollbar-gutter: stable;
  overscroll-behavior: contain;
}

.panel-header {
  margin-bottom: 1.25rem;
  flex-shrink: 0;
}

.panel-header h2 {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
}

/* Overall Progress Indicator */
.progress-bar-container {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.progress-label {
  display: flex;
  justify-content: space-between;
  font-size: 0.75rem;
  color: var(--color-text-muted);
}

.progress-bar {
  width: 100%;
  height: 6px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: 4px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: var(--theme-gradient);
  box-shadow: 0 0 8px var(--color-theme-glow);
  width: 0%;
  transition: width 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Accordion Styles for Lessons list */
.modules-accordion {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.module-card {
  border: 1px solid var(--color-border);
  border-radius: 12px;
  overflow: hidden;
  background: rgba(0, 0, 0, 0.15);
  transition: var(--transition-smooth);
}

.module-card:hover {
  border-color: var(--color-border-hover);
}

.module-card.expanded {
  background: rgba(0, 0, 0, 0.35);
  border-color: rgba(255, 255, 255, 0.15);
}

.module-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem;
  cursor: pointer;
  user-select: none;
}

.module-info h3 {
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 0.2rem;
}

.module-info p {
  font-size: 0.75rem;
  color: var(--color-text-muted);
}

.module-chevron {
  transition: transform 0.3s ease;
  color: var(--color-text-muted);
}

.module-card.expanded .module-chevron {
  transform: rotate(180deg);
  color: var(--color-theme);
}

.module-lessons {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  background: rgba(0, 0, 0, 0.2);
  border-top: 1px solid transparent;
}

.module-card.expanded .module-lessons {
  max-height: 800px;
  border-top-color: var(--color-border);
}

.lesson-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.85rem 1.25rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.03);
  cursor: pointer;
  transition: var(--transition-fast);
}

.lesson-item:last-child {
  border-bottom: none;
}

.lesson-item:hover {
  background: rgba(255, 255, 255, 0.02);
}

.lesson-item.active {
  background: rgba(var(--hue-green), 100%, 54%, 0.04);
  box-shadow: inset 3px 0 0 0 var(--color-theme);
}

body.theme-cyan .lesson-item.active {
  background: rgba(var(--hue-cyan), 100%, 50%, 0.04);
}
body.theme-amber .lesson-item.active {
  background: rgba(var(--hue-amber), 100%, 50%, 0.04);
}
body.theme-pink .lesson-item.active {
  background: rgba(var(--hue-pink), 100%, 60%, 0.04);
}

.lesson-status {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  border: 1px solid var(--color-text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: var(--transition-fast);
}

.lesson-item.completed .lesson-status {
  background: var(--color-theme);
  border-color: var(--color-theme);
  color: var(--color-bg-darker);
}

.lesson-status svg {
  display: none;
  width: 12px;
  height: 12px;
}

.lesson-item.completed .lesson-status svg {
  display: block;
}

.lesson-details {
  display: flex;
  flex-direction: column;
}

.lesson-title {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-text-white);
}

.lesson-item.completed .lesson-title {
  color: var(--color-text-muted);
  text-decoration: line-through;
}

/* Active Lesson Panel Layout */
.active-lesson-box {
  background: rgba(0, 0, 0, 0.35);
  border: 1px solid var(--color-theme-glow);
  border-radius: 12px;
  padding: 1rem;
  margin-top: 1rem;
}

.active-lesson-box h4 {
  font-family: var(--font-display);
  font-size: 0.95rem;
  color: var(--color-theme);
  margin-bottom: 0.5rem;
}

.active-lesson-box p {
  font-size: 0.8rem;
  color: var(--color-text-white);
  line-height: 1.5;
  margin-bottom: 0.75rem;
}

.lesson-task {
  background: rgba(0, 0, 0, 0.5);
  border-radius: 8px;
  padding: 0.75rem;
  border-left: 3px solid var(--color-theme);
}

.task-label {
  font-size: 0.65rem;
  color: var(--color-theme);
  font-weight: 700;
  text-transform: uppercase;
  margin-bottom: 0.25rem;
}

.task-instruction {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: #fff;
}

/* 6. Cheatsheet drawer styling */
.search-box {
  position: relative;
  display: flex;
  align-items: center;
}

.search-icon {
  position: absolute;
  left: 0.75rem;
  color: var(--color-text-muted);
  font-size: 0.85rem;
}

.search-box input {
  width: 100%;
  background: rgba(0, 0, 0, 0.3);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 0.65rem 0.75rem 0.65rem 2.25rem;
  color: #fff;
  font-family: var(--font-sans);
  font-size: 0.85rem;
  transition: var(--transition-fast);
}

.search-box input:focus {
  outline: none;
  border-color: var(--color-theme);
  box-shadow: 0 0 8px var(--color-theme-glow);
}

.cheatsheet-categories {
  display: flex;
  gap: 0.35rem;
  margin-bottom: 1rem;
}

.cat-pill {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--color-border);
  border-radius: 20px;
  padding: 0.35rem 0.75rem;
  font-size: 0.75rem;
  color: var(--color-text-muted);
  cursor: pointer;
  transition: var(--transition-fast);
}

.cat-pill:hover {
  background: rgba(255, 255, 255, 0.08);
  color: #fff;
}

.cat-pill.active {
  background: var(--color-theme-glow);
  border-color: var(--color-theme);
  color: var(--color-theme);
  font-weight: 600;
}

.cheatsheet-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.cheat-card {
  background: rgba(0, 0, 0, 0.2);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 0.85rem;
  transition: var(--transition-fast);
}

.cheat-card:hover {
  border-color: rgba(255, 255, 255, 0.15);
  background: rgba(255, 255, 255, 0.02);
}

.cheat-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.35rem;
}

.cheat-header h3 {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--color-theme);
}

.cheat-category {
  font-size: 0.65rem;
  color: var(--color-text-muted);
  background: rgba(255, 255, 255, 0.05);
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
  text-transform: uppercase;
}

.cheat-desc {
  font-size: 0.75rem;
  color: var(--color-text-muted);
  line-height: 1.4;
  margin-bottom: 0.5rem;
}

.cheat-example {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: rgba(0, 0, 0, 0.3);
  border-radius: 6px;
  padding: 0.4rem 0.6rem;
}

.cheat-example code {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-text-white);
}

.run-btn {
  background: transparent;
  border: none;
  color: var(--color-theme);
  cursor: pointer;
  padding: 0.2rem;
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition-fast);
}

.run-btn:hover {
  background: var(--color-theme-glow);
  color: var(--color-theme);
}

/* 7. Quiz Arena */
.quiz-badge-container {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.quiz-badge {
  background: var(--color-bg-darker);
  border: 1px solid var(--color-border);
  padding: 0.25rem 0.75rem;
  border-radius: 8px;
  font-family: var(--font-display);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--color-theme);
  text-transform: uppercase;
}

.quiz-card {
  background: rgba(0, 0, 0, 0.25);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.quiz-q-num {
  font-size: 0.7rem;
  text-transform: uppercase;
  color: var(--color-text-muted);
  letter-spacing: 0.5px;
}

.quiz-q-text {
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 600;
  line-height: 1.4;
}

.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.quiz-opt-btn {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 0.75rem 1rem;
  color: #fff;
  font-family: var(--font-sans);
  font-size: 0.85rem;
  text-align: left;
  cursor: pointer;
  transition: var(--transition-fast);
}

.quiz-opt-btn:hover {
  background: rgba(255, 255, 255, 0.07);
  border-color: rgba(255, 255, 255, 0.2);
}

.quiz-opt-btn.correct {
  background: rgba(57, 255, 20, 0.1) !important;
  border-color: #39ff14 !important;
  color: #39ff14 !important;
}

.quiz-opt-btn.incorrect {
  background: rgba(255, 30, 30, 0.1) !important;
  border-color: #ff1e1e !important;
  color: #ff1e1e !important;
}

.quiz-stats {
  display: flex;
  justify-content: space-between;
  font-size: 0.75rem;
  color: var(--color-text-muted);
  border-top: 1px solid var(--color-border);
  padding-top: 0.75rem;
}

/* 8. Terminal Shell Styling */
.workspace-main {
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.terminal-card {
  display: flex;
  flex-direction: column;
  flex: 1;
  background: var(--color-bg-darker);
  border: 1px solid var(--color-border);
  border-radius: 20px;
  box-shadow: var(--shadow-premium);
  overflow: hidden;
  position: relative;
}

.terminal-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--theme-gradient);
  z-index: 5;
}

.terminal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: rgba(0, 0, 0, 0.4);
  padding: 0.75rem 1.25rem;
  border-bottom: 1px solid var(--color-border);
}

.window-dots {
  display: flex;
  gap: 0.35rem;
}

.dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.dot-red { background-color: #ff5f56; }
.dot-yellow { background-color: #ffbd2e; }
.dot-green { background-color: #27c93f; }

.terminal-title {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-text-muted);
  max-width: 60%;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.terminal-controls {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  position: relative;
}

.control-btn {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  color: var(--color-text-muted);
  padding: 0.35rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition-fast);
}

.control-btn:hover {
  background: rgba(255, 255, 255, 0.08);
  color: var(--color-text-white);
  border-color: rgba(255, 255, 255, 0.2);
}

.control-btn .active-icon {
  color: var(--color-theme);
  filter: drop-shadow(0 0 3px var(--color-theme-glow));
}

.control-btn .hidden {
  display: none;
}

/* Custom dropdown for themes in terminal header */
.theme-dropdown-menu {
  display: none;
  position: absolute;
  top: calc(100% + 0.5rem);
  right: 0;
  background: rgba(10, 12, 16, 0.95);
  border: 1px solid var(--color-theme);
  border-radius: 12px;
  padding: 0.75rem;
  width: 220px;
  box-shadow: 0 10px 25px rgba(0,0,0,0.8);
  z-index: 100;
  backdrop-filter: blur(12px);
}

.theme-dropdown-menu.visible {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  animation: fadeInDropdown 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

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

.dropdown-section-title {
  font-size: 0.65rem;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin: 0.4rem 0.5rem 0.2rem;
  letter-spacing: 0.5px;
}

.dropdown-item {
  background: transparent;
  border: none;
  color: var(--color-text-white);
  font-family: var(--font-sans);
  font-size: 0.8rem;
  text-align: left;
  padding: 0.5rem 0.75rem;
  border-radius: 6px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  transition: var(--transition-fast);
}

.dropdown-item:hover {
  background: rgba(255, 255, 255, 0.05);
}

.dropdown-item.active {
  background: var(--color-theme-glow);
  color: var(--color-theme);
  font-weight: 600;
}

.color-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}
.dot-cyan-green { background-color: var(--color-primary-green); }
.dot-neon-cyan { background-color: var(--color-primary-cyan); }
.dot-retro-amber { background-color: var(--color-primary-amber); }
.dot-synth-pink { background-color: var(--color-primary-pink); }

.dropdown-divider {
  border: 0;
  border-top: 1px solid var(--color-border);
  margin: 0.35rem 0;
}

.check-box-indicator {
  font-size: 0.75rem;
  width: 14px;
  color: var(--color-theme);
  font-weight: bold;
}

/* Terminal Screen Content */
.terminal-body {
  flex: 1;
  padding: 1.5rem;
  overflow-y: auto;
  scrollbar-gutter: stable;
  overscroll-behavior: contain;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.6;
  color: var(--color-theme);
  cursor: text;
}

.terminal-history {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.ascii-logo {
  font-size: 0.5rem;
  line-height: 1.1;
  white-space: pre;
  color: var(--color-theme);
  opacity: 0.85;
  margin-bottom: 1rem;
  filter: drop-shadow(0 0 4px var(--color-theme-glow));
}

@media (max-width: 600px) {
  .ascii-logo {
    font-size: 0.3rem;
  }
}

.cmd-row {
  display: flex;
  flex-direction: column;
  margin-top: 0.25rem;
}

.cmd-echo {
  display: flex;
  align-items: center;
  font-weight: 600;
  color: var(--color-text-white);
}

.cmd-output {
  margin-left: 0rem;
  color: var(--color-text-muted);
  white-space: pre-wrap;
  word-break: break-all;
  margin-bottom: 0.5rem;
}

.helper-text {
  color: var(--color-text-muted) !important;
}

.cmd-highlight {
  color: var(--color-theme);
  font-weight: bold;
  background: rgba(255, 255, 255, 0.04);
  padding: 0.05rem 0.35rem;
  border-radius: 4px;
  border: 1px solid var(--color-border);
}

.success-glow {
  color: var(--color-theme) !important;
  text-shadow: 0 0 5px var(--color-theme-glow);
}

.divider-line {
  color: var(--color-border) !important;
}

/* Prompt Line in Terminal */
.terminal-prompt-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: 0.25rem;
}

.terminal-prompt {
  font-weight: 700;
  color: var(--color-theme);
  white-space: nowrap;
}

.terminal-input-wrapper {
  display: flex;
  align-items: center;
  flex: 1;
  position: relative;
}

#terminal-input {
  width: 100%;
  background: transparent;
  border: none;
  outline: none;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: #fff;
  padding: 0;
  caret-color: transparent; /* custom cursor */
}

/* Custom blinking cursor */
.virtual-cursor {
  position: absolute;
  width: 8px;
  height: 15px;
  background-color: var(--color-theme);
  box-shadow: 0 0 6px var(--color-theme);
  animation: blink 1s infinite step-end;
  pointer-events: none;
}

@keyframes blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}

/* Virtual Keyboard UI Helper */
.terminal-virtual-keyboard {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  background: rgba(0, 0, 0, 0.5);
  padding: 0.75rem 1.25rem;
  border-top: 1px solid var(--color-border);
}

.keyboard-label {
  font-size: 0.7rem;
  color: var(--color-text-muted);
  text-transform: uppercase;
  font-weight: 600;
}

.key-shortcut {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  color: #fff;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 0.35rem 0.6rem;
  cursor: pointer;
  transition: var(--transition-fast);
}

.key-shortcut:hover {
  background: var(--color-theme-glow);
  color: var(--color-theme);
  border-color: var(--color-theme);
}

/* 9. Footer Components */
.app-footer {
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 0.5rem 0;
  color: var(--color-text-muted);
  font-size: 0.7rem;
}

.footer-meta {
  display: flex;
  gap: 0.75rem;
  align-items: center;
}

/* 10. Animation Effects */
@keyframes successPulse {
  0% { transform: scale(1); box-shadow: 0 0 0 0 rgba(var(--hue-green), 100%, 54%, 0.4); }
  70% { transform: scale(1.02); box-shadow: 0 0 0 10px rgba(var(--hue-green), 100%, 54%, 0); }
  100% { transform: scale(1); box-shadow: 0 0 0 0 rgba(var(--hue-green), 100%, 54%, 0); }
}

.completed-pulse {
  animation: successPulse 0.5s ease-out;
}

/* Custom Scrollbars */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: rgba(0, 0, 0, 0.1);
}

::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.08);
  border-radius: 4px;
  transition: var(--transition-fast);
}

::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.15);
}