:root {
  /* Base variables - Defaulting to Aether (Blue) logic structure but overridden by data-theme */
  --bg-color: #f0f9ff;
  --text-color: #334155;
  --sidebar-bg: rgba(255, 255, 255, 0.95);
  --sidebar-border: #bae6fd;
  --accent-color: #0284c7;
  --link-color: #0ea5e9;
  --font-main: 'Quicksand', sans-serif;
  --font-mono: 'Courier New', monospace;
  --card-bg: #ffffff;
  --card-border: #e0f2fe;
  --btn-hover: #e0f2fe;
  --heading-weight: 700;
  --table-head-bg: #e0f2fe;
  --table-border: #bae6fd;
}

/* 1. AETHER (Default/Blue) - Kawaii/Readable */
[data-theme="aether"] {
  --bg-color: #f0f9ff;
  --text-color: #334155;
  --sidebar-bg: rgba(255, 255, 255, 0.95);
  --sidebar-border: #bae6fd;
  --accent-color: #0284c7;
  --link-color: #0ea5e9;
  --font-main: 'Quicksand', sans-serif;
  --font-mono: 'Consolas', monospace;
  --card-bg: #ffffff;
  --card-border: #e0f2fe;
  --btn-hover: #e0f2fe;
  --heading-weight: 700;
  --table-head-bg: #e0f2fe;
  --table-border: #bae6fd;
}

/* 2. SANCTUARY (Pink) - Elegant/Serif */
[data-theme="sanctuary"] {
  --bg-color: #fff1f2;
  --text-color: #334155;
  --sidebar-bg: rgba(255, 255, 255, 0.95);
  --sidebar-border: #fecdd3;
  --accent-color: #be123c;
  --link-color: #e11d48;
  --font-main: 'Cormorant Garamond', serif;
  --font-mono: 'Courier New', monospace;
  --card-bg: #ffffff;
  --card-border: #ffe4e6;
  --btn-hover: #fff5f5;
  --heading-weight: 600;
  --table-head-bg: #ffe4e6;
  --table-border: #fda4af;
}

/* 3. TERMINAL (Green) - Hacker */
[data-theme="terminal"] {
  --bg-color: #000000;
  --text-color: #39ff14;
  --sidebar-bg: #000000;
  --sidebar-border: #39ff14;
  --accent-color: #00ffff;
  --link-color: #00ffff;
  --font-main: 'VT323', monospace;
  --font-mono: 'VT323', monospace;
  --card-bg: #000000;
  --card-border: #008f11;
  --btn-hover: #003300;
  --heading-weight: 400;
  --table-head-bg: #001100;
  --table-border: #39ff14;
}

/* 4. WORKSTATION (Grey) - Retro */
[data-theme="workstation"] {
  --bg-color: #c0c0c0;
  --text-color: #000000;
  --sidebar-bg: #c0c0c0;
  --sidebar-border: #808080;
  --accent-color: #000080;
  --link-color: #0000ff;
  --font-main: 'Inter', sans-serif;
  --font-mono: 'Consolas', monospace;
  --card-bg: #ffffff;
  --card-border: #000000;
  --btn-hover: #dcdcdc;
  --heading-weight: 700;
  --table-head-bg: #dcdcdc;
  --table-border: #808080;
}

/* Base Reset */
* { box-sizing: border-box; }
body {
  margin: 0;
  padding: 0;
  background-color: var(--bg-color);
  color: var(--text-color);
  font-family: var(--font-main);
  transition: background-color 0.3s, color 0.3s;
  height: 100vh;
  overflow: hidden;
  display: flex;
}

/* CRT Effect for Terminal */
[data-theme="terminal"] body::before {
  content: " ";
  display: block;
  position: absolute;
  top: 0; left: 0; bottom: 0; right: 0;
  background: linear-gradient(rgba(18, 16, 16, 0) 50%, rgba(0, 0, 0, 0.25) 50%), linear-gradient(90deg, rgba(255, 0, 0, 0.06), rgba(0, 255, 0, 0.02), rgba(0, 0, 255, 0.06));
  z-index: 100;
  background-size: 100% 2px, 3px 100%;
  pointer-events: none;
}

/* Layout */
#sidebar {
  width: 300px;
  height: 100%;
  overflow-y: auto;
  background: var(--sidebar-bg);
  border-right: 1px solid var(--sidebar-border);
  padding: 1.5rem;
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
}

/* Workstation Bevels */
[data-theme="workstation"] #sidebar {
  border-right: 2px solid #808080;
  border-left: 1px solid #ffffff;
  border-top: 1px solid #ffffff;
}

#main-content {
  flex: 1;
  overflow-y: auto;
  padding: 2rem 4rem;
  max-width: 100%;
}

[data-theme="workstation"] #main-content {
  background: #ffffff;
  margin: 8px;
  border: 2px inset #dfdfdf;
  padding: 2rem;
}

/* Typography */
h1, h2, h3, h4, h5 {
  color: var(--accent-color);
  font-weight: var(--heading-weight);
  margin-top: 1.5em;
  margin-bottom: 0.5em;
}

h1 { font-size: 2.5rem; border-bottom: 1px solid var(--sidebar-border); padding-bottom: 0.5rem; }
h2 { font-size: 1.8rem; }
p { line-height: 1.6; margin-bottom: 1rem; font-size: 1.1rem; }
a { color: var(--link-color); text-decoration: none; }
a:hover { text-decoration: underline; }
blockquote {
  border-left: 4px solid var(--accent-color);
  padding-left: 1rem;
  margin: 1.5rem 0;
  font-style: italic;
  opacity: 0.8;
}
code { font-family: var(--font-mono); background: rgba(0,0,0,0.05); padding: 0.2em 0.4em; border-radius: 3px; }
pre { background: #1a1a1a; color: #f8f8f2; padding: 1rem; border-radius: 0.5rem; overflow-x: auto; }

/* Table Styles */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.95rem;
}

th, td {
  padding: 0.75rem;
  border: 1px solid var(--table-border);
  text-align: left;
}

th {
  background-color: var(--table-head-bg);
  font-weight: bold;
}

[data-theme="terminal"] th {
  text-transform: uppercase;
}

/* Search Bar */
#search-container {
  margin-bottom: 1.5rem;
}
#search-input {
  width: 100%;
  padding: 0.5rem;
  border: 1px solid var(--sidebar-border);
  border-radius: 4px;
  background: transparent;
  color: var(--text-color);
  font-family: var(--font-main);
  outline: none;
}
#search-input:focus {
  border-color: var(--accent-color);
}
[data-theme="terminal"] #search-input {
  border: 1px solid var(--text-color);
  background: #000;
}
[data-theme="workstation"] #search-input {
  background: #fff;
  border: 2px inset #dfdfdf;
}


/* Navigation */
.nav-group { margin-bottom: 0.5rem; }

.nav-group-header {
  font-weight: bold;
  text-transform: uppercase;
  font-size: 0.85rem;
  opacity: 0.8;
  padding: 0.5rem 0;
  letter-spacing: 0.05em;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}
.nav-group-header:hover {
  color: var(--accent-color);
  opacity: 1;
}

.nav-group-content {
  display: none; /* Collapsed by default */
  padding-left: 0.5rem;
  border-left: 1px solid var(--sidebar-border);
  margin-left: 0.2rem;
  margin-bottom: 0.5rem;
}

.nav-group.expanded .nav-group-content {
  display: block;
}

.nav-item {
  display: block;
  padding: 0.4rem 0.5rem;
  border-radius: 4px;
  color: var(--text-color);
  margin-bottom: 2px;
  font-size: 1rem;
}
.nav-item:hover {
  background-color: var(--btn-hover);
  color: var(--accent-color);
}
.nav-item.active {
  background-color: var(--btn-hover);
  color: var(--accent-color);
  font-weight: bold;
  border-left: 3px solid var(--accent-color);
}
/* Hidden helper for search logic */
.nav-item.hidden-search {
  display: none !important;
}
.nav-group.hidden-search {
  display: none !important;
}

/* Theme Switcher */
#theme-controls {
  margin-top: auto;
  padding-top: 1rem;
  border-top: 1px solid var(--sidebar-border);
  display: flex;
  gap: 8px;
}
.theme-btn {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  border: 2px solid transparent;
  cursor: pointer;
  display: inline-block;
}
.theme-btn:hover { transform: scale(1.1); }
#btn-aether { background: #f0f9ff; border-color: #0284c7; }
#btn-sanctuary { background: #fff1f2; border-color: #be123c; }
#btn-terminal { background: #000000; border-color: #39ff14; }
#btn-workstation { background: #c0c0c0; border: 2px solid #000000; }

/* Responsive */
@media (max-width: 768px) {
  body { flex-direction: column; }
  #sidebar { width: 100%; height: auto; max-height: 200px; border-right: none; border-bottom: 1px solid var(--sidebar-border); }
  #main-content { padding: 1.5rem; }
}