:root {
  --glass-bg: rgba(255, 255, 255, 0.65);
  --glass-border: rgba(255, 255, 255, 0.4);
  --glass-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.10);
  --primary-color: #007aff;
  --text-color: #1c1c1e;
  --secondary-text: #8e8e93;
  --danger-color: #ff3b30;
  --success-color: #34c759;
  --bg-gradient: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
  --sidebar-width: 300px;
  --header-height: 60px;
  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-sm: 10px;
  --font-stack: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", sans-serif;
}

* {
  box-sizing: border-box;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: var(--font-stack);
  margin: 0;
  padding: 0;
  background: #eef2f5; /* Fallback */
  background: var(--bg-gradient);
  color: var(--text-color);
  height: 100vh;
  overflow: hidden;
  font-size: 14px;
}

/* Layout */
.app-container {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  grid-template-rows: var(--header-height) 1fr;
  height: 100vh;
  width: 100vw;
}

/* Header */
.app-header {
  grid-column: 1 / -1;
  background: var(--glass-bg);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--glass-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  z-index: 100;
}

.brand {
  font-weight: 600;
  font-size: 18px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.brand-icon {
  width: 24px;
  height: 24px;
  background: var(--primary-color);
  border-radius: 8px;
}

.header-controls {
  display: flex;
  gap: 16px;
  align-items: center;
}

/* Sidebar */
.app-sidebar {
  grid-row: 2;
  background: rgba(255, 255, 255, 0.5);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-right: 1px solid var(--glass-border);
  overflow-y: auto;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 20px;
  z-index: 90;
}

/* Main Content (Graph) */
.app-main {
  grid-column: 2;
  grid-row: 2;
  position: relative;
  overflow: hidden;
}

#graph {
  width: 100%;
  height: 100%;
  background: transparent;
}

/* UI Components */
.card {
  background: rgba(255, 255, 255, 0.7);
  border-radius: var(--radius-md);
  padding: 16px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.05);
  border: 1px solid rgba(255,255,255,0.5);
}

.section-title {
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--secondary-text);
  margin-bottom: 12px;
  font-weight: 600;
}

/* Inputs & Buttons */
input, select, textarea {
  width: 100%;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(0,0,0,0.1);
  background: rgba(255,255,255,0.8);
  font-family: inherit;
  font-size: 14px;
  transition: all 0.2s;
  outline: none;
}

input:focus, select:focus, textarea:focus {
  border-color: var(--primary-color);
  background: #fff;
  box-shadow: 0 0 0 3px rgba(0, 122, 255, 0.2);
}

button {
  background: var(--primary-color);
  color: white;
  border: none;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
}

button:hover {
  filter: brightness(1.1);
  transform: translateY(-1px);
}

button:active {
  transform: translateY(0);
}

button.secondary {
  background: rgba(0,0,0,0.05);
  color: var(--text-color);
}

button.danger {
  background: var(--danger-color);
}

button.icon-btn {
  padding: 8px;
  border-radius: 50%;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(255,255,255,0.5);
}

/* Lists */
.list-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.list-item {
  background: rgba(255,255,255,0.6);
  padding: 10px;
  border-radius: var(--radius-sm);
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  transition: background 0.2s;
  border: 1px solid transparent;
}

.list-item:hover {
  background: rgba(255,255,255,0.9);
  border-color: rgba(0,0,0,0.05);
}

.list-item.active {
  background: white;
  border-color: var(--primary-color);
  box-shadow: 0 2px 8px rgba(0, 122, 255, 0.15);
}

/* Floating Panels / Modals */
.floating-panel {
  position: absolute;
  top: 20px;
  right: 20px;
  width: 320px;
  max-height: calc(100% - 40px);
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: saturate(180%) blur(25px);
  -webkit-backdrop-filter: saturate(180%) blur(25px);
  border-radius: var(--radius-lg);
  box-shadow: var(--glass-shadow);
  border: 1px solid var(--glass-border);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transition: transform 0.3s cubic-bezier(0.19, 1, 0.22, 1), opacity 0.3s ease;
  z-index: 50;
  transform: translateX(350px);
  opacity: 0;
  pointer-events: none;
}

.floating-panel.visible {
  transform: translateX(0);
  opacity: 1;
  pointer-events: auto;
}

.panel-header {
  padding: 16px 20px;
  border-bottom: 1px solid rgba(0,0,0,0.05);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-weight: 600;
  font-size: 16px;
}

.panel-content {
  padding: 20px;
  overflow-y: auto;
  flex: 1;
}

.panel-footer {
  padding: 16px 20px;
  border-top: 1px solid rgba(0,0,0,0.05);
  background: rgba(255,255,255,0.3);
}

/* Context Menu */
.context-menu {
  position: absolute;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(20px);
  border-radius: 12px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.15);
  padding: 6px;
  min-width: 160px;
  z-index: 200;
  display: none;
  border: 1px solid rgba(255,255,255,0.5);
}

.context-menu-item {
  padding: 8px 12px;
  border-radius: 8px;
  cursor: pointer;
  font-size: 13px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.context-menu-item:hover {
  background: var(--primary-color);
  color: white;
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: rgba(0,0,0,0.1);
  border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover {
  background: rgba(0,0,0,0.2);
}

/* Utilities */
.hidden { display: none !important; }
.flex-row { display: flex; gap: 8px; align-items: center; }
.flex-col { display: flex; flex-direction: column; gap: 8px; }
.space-between { justify-content: space-between; }
.text-sm { font-size: 12px; color: var(--secondary-text); }
.mt-2 { margin-top: 8px; }
.mb-2 { margin-bottom: 8px; }
.p-2 { padding: 8px; }
.full-width { width: 100%; }

/* Search Bar */
.search-bar {
  position: relative;
  width: 300px;
}
.search-bar input {
  padding-left: 36px;
  border-radius: 20px;
  background: rgba(0,0,0,0.05);
  border: none;
}
.search-icon {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  opacity: 0.5;
}

/* Tags */
.tag {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 12px;
  background: rgba(0, 122, 255, 0.1);
  color: var(--primary-color);
  font-size: 11px;
  margin-right: 4px;
}

/* Tabs */
.tabs {
  display: flex;
  gap: 4px;
  padding: 4px;
  background: rgba(0,0,0,0.05);
  border-radius: 12px;
  margin-bottom: 16px;
}

.tab-btn {
  flex: 1;
  background: transparent;
  color: var(--secondary-text);
  padding: 6px;
  font-size: 12px;
  border-radius: 8px;
}

.tab-btn.active {
  background: white;
  color: var(--text-color);
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}