:root {
  /* Dark - 'nyon' near-black with purple accents and subtle neon highlights */
  --primary-color: #4964f2; /* purple accent */
  --primary-variant: #6849f2;
  --bg-color: #050507; /* nyon: very deep black with tiny cool tint */
  --sidebar-bg: #07070a;
  --text-color: #ffffff; /* soft, slightly cool text for readability */
  --heading-color: #58A6FF; /* brighter headings for contrast */
  --border-color: rgba(124,92,255,0.08);
  --hover-color: rgba(255,255,255,0.02);
  --active-color: var(--primary-color);
  --card-bg: #0b0b10; /* slightly lighter than bg for separation */
  --code-bg: #060608;
  --success-color: #22c55e; /* subtle neon green */
  --muted-color: rgba(207, 209, 238, 0.6);
  --active-bg: rgba(124,92,255,0.06);
  --btn-text: #0a0710;
  --code-inline-bg: rgba(34,197,94,0.06);
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
}

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

body {
  font-family: var(--font-family);
  background-color: var(--bg-color);
  color: var(--text-color);
  line-height: 1.6;
  min-height: 100vh;
  overflow: auto;
  transition: background-color 240ms ease, color 240ms ease;
}

/* Smooth cross-fade for more properties */
* {
  transition: background-color 240ms ease, color 240ms ease, border-color 240ms ease, box-shadow 240ms ease, transform 160ms ease;
}

.app-container {
  display: flex;
  height: 100%;
}

/* Sidebar */
.sidebar {
  width: 300px;
  background-color: var(--sidebar-bg);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  transition: transform 0.3s ease;
  flex-shrink: 0;
}

.sidebar-header {
  padding: 1.5rem;
  border-bottom: 1px solid var(--border-color);
}

.sidebar-header h1 {
  font-size: 1.25rem;
  color: var(--heading-color);
  font-weight: 600;
}

.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  padding: 1rem 0;
}

.phase-group {
  margin-bottom: 1rem;
}

.phase-title {
  padding: 0.50rem;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--muted-color);
  font-weight: 600;
}

.module-link {
  display: block;
  padding: 0.25rem;
  color: var(--text-color);
  text-decoration: none;
  font-size: 0.9rem;
  border-left: 3px solid transparent;
  cursor: pointer;
  transition: all 0.2s ease;
}

.module-link:hover {
  background-color: var(--hover-color);  
  border-left-color: var(--primary-color);
  color: var(--heading-color);
  text-decoration: none;
}

.module-link.active {
  background-color: var(--active-bg);
  border-left-color: var(--primary-color);
  color: var(--heading-color);
}

.module-link.completed::after {
  content: '✓';
  float: right;
  color: var(--success-color);
}

/* Main Content */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: visible;
  position: relative;
}

.top-bar {    
  height: max-content;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  padding: 1rem 1.5rem;
  background-color: var(--bg-color);
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-color);
  cursor: pointer;
}

.progress-container {
  display: flex;
  align-items: center;
  gap: 1rem;
  font-size: 0.875rem;
  flex: 1 1 auto;
  min-width: 0;
}

.progress-bar {
  flex-basis: 150px;
  max-width: 40%;
  min-width: 64px;
  height: 8px;
  background-color: var(--border-color);
  border-radius: 4px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background-color: var(--success-color);
  transition: width 0.3s ease;
}

.content-area {
    flex: 1;
    overflow-y: auto;
    padding: 1.5rem;
    padding-bottom: 4.5rem;
    width: 100%;
    margin-top: 2rem;
}

/* Content Styling */
h1,
h2,
h3 {
  color: var(--heading-color);
  margin-bottom: 1rem;
}

h1 {
  font-size: 2rem;
  margin-bottom: 1.5rem;
}

h2 {
  font-size: 1.5rem;
  margin-top: 2rem;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.5rem;
}

h3 {
  font-size: 1.25rem;
  margin-top: 1.5rem;
}

p {
  margin-bottom: 1rem;
  text-align: justify;
}

ul,
ol {
  margin-bottom: 1rem;
  padding-left: 1.5rem;
}

li {
  margin-bottom: 0.5rem;
}

a {
  color: var(--primary-color);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

code {
  background-color: var(--code-inline-bg);
  padding: 0.2em 0.4em;
  border-radius: 6px;
  font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
  font-size: 85%;
}

pre {
  background-color: var(--card-bg);
  padding: 1rem;
  border-radius: 6px;
  overflow-x: auto;
  margin-bottom: 1rem;
  border: 1px solid var(--border-color);
}

pre code {
  background-color: transparent;
  padding: 0;
  font-size: 100%;
}

.card {
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 1rem;  
}

.card-highlight {
  background-color: var(--active-bg);   
}

.btn {
  display: inline-block;
  padding: 0.5rem 1rem;
  background-color: var(--primary-color);
  color: var(--btn-text);
  border-radius: 6px;
  text-decoration: none;
  font-weight: 500;
  cursor: pointer;
  border: none;
  transition: background-color 0.15s ease, transform 0.12s ease;
}

.btn:hover {
  background-color: var(--primary-variant);
  text-decoration: none;
}

.btn-secondary {
  background-color: var(--border-color);
  color: var(--text-color);
}

.btn-secondary:hover {
  background-color: var(--hover-color);
}

/* Responsive */
@media (max-width: 768px) {
  .sidebar {
    position: absolute;
    height: 100%;
    z-index: 100;
    transform: translateX(-100%);
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .menu-toggle {
    display: block;
  }
  .top-bar {  
  position: fixed;
  width: 100%;
}

  /* Ensure header content aligns: menu left, progress center (if space), social to the right */
  .top-bar {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
  }

  .menu-toggle {
    order: 0;
    margin-right: 0.5rem;
  }

  /* Prevent wrapping so hamburger and socials stay on same row */
  .top-bar {
    flex-wrap: nowrap;
    justify-content: flex-start;
  }

  .progress-container {
    order: 1;
    flex: 1 1 auto;
    min-width: 0;
    display: flex;
    align-items: center;
    gap: 0.5rem;
  }

  .social-links {
    order: 2;
    margin-left: auto;
  }

  /* Reduce spacing of social icons on small screens */
  .social-links a {
    padding: 0.35rem;
  }
}
/* Light Theme */
[data-theme="light"] {
  /* Light theme - green friendly accents */
  --primary-color: #0969da; /* emerald green */
  --primary-variant:#4964f2;
  --bg-color: #ffffff;
  --sidebar-bg: #f6f8fa;
  --text-color: #24292f;
  --heading-color: #24292f;
  --border-color: #d0d7de;
  --hover-color: rgba(56, 139, 253, 0.1);
  --active-color: #0969da;
  --card-bg: #f6f8fa;
  --code-bg: #f6f8fa;
  --muted-color: #8b949e;
  --active-bg:rgba(56, 139, 253, 0.1);
  --btn-text: #ffffff;
  --code-inline-bg: rgba(22,163,74,0.06);
}

/* Theme Toggle Button */
.theme-toggle {
  background: none;
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 0.5rem;
  cursor: pointer;
  color: var(--text-color);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease;
  margin-left: 1rem;
}

.theme-toggle:hover {
  background-color: var(--hover-color);
  border-color: var(--primary-color);
}

.theme-toggle .sun-icon,
.theme-toggle .moon-icon {
  opacity: 0;
  transform: scale(0.9) translateY(2px);
  transition: opacity 220ms ease, transform 220ms ease;
}

.theme-toggle .sun-icon {
  opacity: 0;
  transform: scale(0.9) translateY(2px);
  transition: opacity 220ms ease, transform 220ms ease;
}

/* Dark mode: show sun icon (switch to light) */
:root:not([data-theme="light"]) .theme-toggle .sun-icon {
  opacity: 1;
  transform: scale(1) translateY(0);
}

/* Light mode: show moon icon (switch to dark) */
:root[data-theme="light"] .theme-toggle .moon-icon,
[data-theme="light"] .theme-toggle .moon-icon {
  opacity: 1;
  transform: scale(1) translateY(0);
}

/* Social Links */
.social-links {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-left: auto;
  min-width: 0;
  padding: 5px;
}

.social-links a {
  color: var(--text-color);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0.5rem;
  border-radius: 6px;
  transition: all 0.2s ease;
  text-decoration: none;
}

.social-links a:hover {
  background-color: var(--hover-color);
  color: var(--primary-color);
  transform: translateY(-2px);
}

/* Footer styles */
.app-footer {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--sidebar-bg);
  border-top: 1px solid var(--border-color);
  padding: 0.5rem 1rem;
  z-index: 80;
}

.app-footer .footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 1rem;
  justify-content: space-between;
}

.app-footer .social-links {
  margin: 0;
  gap: 0.5rem;
}

.app-footer .social-links a,
.app-footer .social-links button {
  color: var(--text-color);
}

.footer-copy {
  color: var(--muted-color);
  font-size: 0.85rem;
}

/* On very small screens, reduce footer padding */
@media (max-width: 420px) {
  .app-footer { padding: 0.4rem 0.75rem; }

  .app-footer .footer-inner {    
    display: block;
    text-align: center; 
  }
  .social-links {
    display: ruby;
    align-items: center;
    gap: 0.75rem;
    margin-top: 0.5rem;
  }
}

.social-links svg {
  width: 20px;
  height: 20px;
}