/* ==========================================================================
   Design System & Modern Styling
   ========================================================================== */

:root {
  /* Common Variables */
  --font-family-sans: 'Inter', 'Noto Sans KR', sans-serif;
  --font-family-display: 'Outfit', 'Noto Sans KR', sans-serif;
  
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  
  --border-radius-sm: 6px;
  --border-radius-md: 10px;
  --border-radius-lg: 16px;
  --border-radius-pill: 9999px;
  
  --sidebar-width: 380px;
  
  /* Dark Theme Default (Classic Dark fallback) */
  --bg-app: #090d16;
  --bg-canvas: #0c1220;
  --bg-sidebar: rgba(13, 20, 35, 0.8);
  --bg-card: rgba(22, 32, 55, 0.75);
  --bg-card-hover: rgba(30, 43, 73, 0.9);
  --bg-input: #111a2e;
  
  --border-color: rgba(255, 255, 255, 0.08);
  --border-color-hover: rgba(255, 255, 255, 0.15);
  
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  
  --accent-color: #6366f1; /* Indigo-500 */
  --accent-color-hover: #4f46e5;
  --accent-gradient: linear-gradient(135deg, #6366f1 0%, #a855f7 100%);
  --accent-shadow: rgba(99, 102, 241, 0.25);
  
  --grid-color: rgba(255, 255, 255, 0.03);
  
  /* Node colors */
  --node-root-bg: linear-gradient(135deg, #6366f1 0%, #3b82f6 100%);
  --node-root-text: #ffffff;
  --node-bg: rgba(17, 24, 39, 0.85);
  --node-text: #e2e8f0;
  --node-border-default: rgba(255, 255, 255, 0.15);
}

/* ==========================================================================
   Theme Configurations
   ========================================================================== */

/* 1. Classic Dark */
body.theme-classic-dark {
  --bg-app: #090d16;
  --bg-canvas: #0c1220;
  --bg-sidebar: rgba(13, 20, 35, 0.8);
  --bg-card: rgba(22, 32, 55, 0.75);
  --bg-card-hover: rgba(30, 43, 73, 0.9);
  --bg-input: #111a2e;
  
  --border-color: rgba(255, 255, 255, 0.08);
  --border-color-hover: rgba(255, 255, 255, 0.15);
  
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  
  --accent-color: #6366f1;
  --accent-color-hover: #4f46e5;
  --accent-gradient: linear-gradient(135deg, #6366f1 0%, #a855f7 100%);
  --accent-shadow: rgba(99, 102, 241, 0.25);
  
  --grid-color: rgba(255, 255, 255, 0.03);
  
  --node-root-bg: linear-gradient(135deg, #6366f1 0%, #3b82f6 100%);
  --node-root-text: #ffffff;
  --node-bg: rgba(17, 24, 39, 0.85);
  --node-text: #e2e8f0;
  --node-border-default: rgba(255, 255, 255, 0.15);
}

/* 2. Classic Light */
body.theme-classic-light {
  --bg-app: #f1f5f9;
  --bg-canvas: #f8fafc;
  --bg-sidebar: rgba(255, 255, 255, 0.8);
  --bg-card: rgba(255, 255, 255, 0.85);
  --bg-card-hover: rgba(255, 255, 255, 0.95);
  --bg-input: #ffffff;
  
  --border-color: rgba(0, 0, 0, 0.08);
  --border-color-hover: rgba(0, 0, 0, 0.15);
  
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  
  --accent-color: #4f46e5;
  --accent-color-hover: #3730a3;
  --accent-gradient: linear-gradient(135deg, #4f46e5 0%, #7c3aed 100%);
  --accent-shadow: rgba(79, 70, 229, 0.15);
  
  --grid-color: rgba(0, 0, 0, 0.03);
  
  --node-root-bg: linear-gradient(135deg, #4f46e5 0%, #06b6d4 100%);
  --node-root-text: #ffffff;
  --node-bg: rgba(255, 255, 255, 0.95);
  --node-text: #1e293b;
  --node-border-default: rgba(0, 0, 0, 0.1);
}

/* 3. Nordic Frost */
body.theme-nord {
  --bg-app: #2e3440;
  --bg-canvas: #3b4252;
  --bg-sidebar: rgba(46, 52, 64, 0.85);
  --bg-card: rgba(46, 52, 64, 0.7);
  --bg-card-hover: rgba(59, 66, 82, 0.9);
  --bg-input: #2e3440;
  
  --border-color: rgba(216, 222, 233, 0.12);
  --border-color-hover: rgba(216, 222, 233, 0.22);
  
  --text-primary: #d8dee9;
  --text-secondary: #e5e9f0;
  --text-muted: #4c566a;
  
  --accent-color: #88c0d0;
  --accent-color-hover: #81a1c1;
  --accent-gradient: linear-gradient(135deg, #88c0d0 0%, #81a1c1 100%);
  --accent-shadow: rgba(136, 192, 208, 0.25);
  
  --grid-color: rgba(216, 222, 233, 0.03);
  
  --node-root-bg: linear-gradient(135deg, #88c0d0 0%, #5e81ac 100%);
  --node-root-text: #2e3440;
  --node-bg: rgba(46, 52, 64, 0.95);
  --node-text: #e5e9f0;
  --node-border-default: rgba(216, 222, 233, 0.15);
}

/* 4. Forest Moss */
body.theme-forest {
  --bg-app: #141b15;
  --bg-canvas: #1a231b;
  --bg-sidebar: rgba(20, 27, 21, 0.85);
  --bg-card: rgba(26, 35, 27, 0.75);
  --bg-card-hover: rgba(37, 49, 39, 0.9);
  --bg-input: #141b15;
  
  --border-color: rgba(167, 243, 208, 0.08);
  --border-color-hover: rgba(167, 243, 208, 0.15);
  
  --text-primary: #ecfdf5;
  --text-secondary: #a7f3d0;
  --text-muted: #065f46;
  
  --accent-color: #10b981;
  --accent-color-hover: #059669;
  --accent-gradient: linear-gradient(135deg, #10b981 0%, #059669 100%);
  --accent-shadow: rgba(16, 185, 129, 0.25);
  
  --grid-color: rgba(167, 243, 208, 0.03);
  
  --node-root-bg: linear-gradient(135deg, #10b981 0%, #047857 100%);
  --node-root-text: #ffffff;
  --node-bg: rgba(26, 35, 27, 0.95);
  --node-text: #a7f3d0;
  --node-border-default: rgba(167, 243, 208, 0.15);
}

/* 5. Neon Sunset */
body.theme-sunset {
  --bg-app: #0f081d;
  --bg-canvas: #160e2b;
  --bg-sidebar: rgba(15, 8, 29, 0.85);
  --bg-card: rgba(29, 18, 54, 0.75);
  --bg-card-hover: rgba(41, 26, 75, 0.9);
  --bg-input: #120924;
  
  --border-color: rgba(244, 63, 94, 0.12);
  --border-color-hover: rgba(244, 63, 94, 0.2);
  
  --text-primary: #fff1f2;
  --text-secondary: #fda4af;
  --text-muted: #9f1239;
  
  --accent-color: #f43f5e;
  --accent-color-hover: #ec4899;
  --accent-gradient: linear-gradient(135deg, #f43f5e 0%, #d946ef 100%);
  --accent-shadow: rgba(244, 63, 150, 0.25);
  
  --grid-color: rgba(244, 63, 94, 0.03);
  
  --node-root-bg: linear-gradient(135deg, #f43f5e 0%, #e11d48 100%);
  --node-root-text: #ffffff;
  --node-bg: rgba(29, 18, 54, 0.95);
  --node-text: #fda4af;
  --node-border-default: rgba(244, 63, 94, 0.15);
}

/* 6. Solarized Amber */
body.theme-solarized {
  --bg-app: #fdf6e3;
  --bg-canvas: #eee8d5;
  --bg-sidebar: rgba(253, 246, 227, 0.85);
  --bg-card: rgba(253, 246, 227, 0.9);
  --bg-card-hover: rgba(238, 232, 213, 0.95);
  --bg-input: #fdf6e3;
  
  --border-color: rgba(101, 123, 131, 0.15);
  --border-color-hover: rgba(101, 123, 131, 0.25);
  
  --text-primary: #586e75;
  --text-secondary: #657b83;
  --text-muted: #93a1a1;
  
  --accent-color: #b58900;
  --accent-color-hover: #cb4b16;
  --accent-gradient: linear-gradient(135deg, #b58900 0%, #cb4b16 100%);
  --accent-shadow: rgba(181, 137, 0, 0.2);
  
  --grid-color: rgba(101, 123, 131, 0.05);
  
  --node-root-bg: linear-gradient(135deg, #b58900 0%, #cb4b16 100%);
  --node-root-text: #ffffff;
  --node-bg: rgba(253, 246, 227, 0.95);
  --node-text: #586e75;
  --node-border-default: rgba(101, 123, 131, 0.15);
}

/* ==========================================================================
   Reset & Base Styles
   ========================================================================== */

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

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  font-family: var(--font-family-sans);
  background-color: var(--bg-app);
  color: var(--text-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

button, input, textarea {
  font-family: inherit;
  font-size: inherit;
  color: inherit;
  outline: none;
}

/* ==========================================================================
   App Layout
   ========================================================================== */

.app-wrapper {
  display: flex;
  width: 100vw;
  height: 100vh;
  position: relative;
  overflow: hidden;
}

/* Sidebar Styling (Markdown Editor) */
.sidebar {
  width: var(--sidebar-width);
  height: 100%;
  background-color: var(--bg-sidebar);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  transition: margin-left var(--transition-normal);
  z-index: 10;
  flex-shrink: 0;
  margin-left: 0;
}

.sidebar.collapsed {
  margin-left: calc(-1 * var(--sidebar-width));
  pointer-events: none;
}

.sidebar-header {
  padding: 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--border-color);
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-icon {
  color: var(--accent-color);
}

.logo h2 {
  font-family: var(--font-family-display);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.5px;
}

.editor-container {
  flex: 1;
  padding: 16px;
  display: flex;
  flex-direction: column;
}

#markdown-input {
  flex: 1;
  width: 100%;
  background-color: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-md);
  padding: 16px;
  resize: none;
  font-family: 'Courier New', Courier, monospace;
  font-size: 14px;
  line-height: 1.6;
  color: var(--text-primary);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

#markdown-input:focus {
  border-color: var(--accent-color);
  box-shadow: 0 0 0 3px var(--accent-shadow);
}

.sidebar-footer {
  padding: 16px 20px;
  background-color: rgba(0, 0, 0, 0.1);
  border-top: 1px solid var(--border-color);
}

.footer-tips {
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: 12px;
}

.tip-title {
  font-weight: 600;
  color: var(--accent-color);
}

.tip-desc {
  color: var(--text-secondary);
  line-height: 1.4;
}

/* Main Content Area */
.main-content {
  flex: 1;
  height: 100%;
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
  background-color: var(--bg-canvas);
}

/* Top Bar Styling */
.topbar {
  height: 64px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 24px;
  background-color: rgba(var(--bg-app), 0.5);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  z-index: 5;
}

.topbar-left {
  display: flex;
  align-items: center;
  gap: 16px;
}

.app-title {
  font-family: var(--font-family-display);
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -0.5px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.badge {
  font-family: var(--font-family-sans);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0;
  background: var(--accent-gradient);
  color: #ffffff;
  padding: 2px 6px;
  border-radius: var(--border-radius-sm);
  text-transform: uppercase;
}

.topbar-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

/* Canvas Container */
.canvas-container {
  flex: 1;
  position: relative;
  overflow: hidden;
}

#mindmap-svg {
  display: block;
  cursor: grab;
}

#mindmap-svg:active {
  cursor: grabbing;
}

#grid-bg {
  color: var(--text-primary);
}

/* ==========================================================================
   UI Components & Controls
   ========================================================================== */

/* Icon Buttons */
.icon-button {
  width: 38px;
  height: 38px;
  border-radius: var(--border-radius-md);
  border: 1px solid var(--border-color);
  background-color: var(--bg-card);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.icon-button:hover {
  background-color: var(--bg-card-hover);
  border-color: var(--border-color-hover);
  color: var(--accent-color);
}

/* Standard Buttons */
.action-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  height: 38px;
  border-radius: var(--border-radius-md);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
  border: 1px solid transparent;
}

.primary-btn {
  background: var(--accent-gradient);
  color: #ffffff;
  border: none;
  box-shadow: 0 4px 12px var(--accent-shadow);
}

.primary-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 16px var(--accent-shadow);
}

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

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

.upload-btn {
  position: relative;
}

/* Canvas Floating Controls */
.canvas-controls {
  position: absolute;
  bottom: 24px;
  right: 24px;
  display: flex;
  align-items: center;
  background-color: var(--bg-sidebar);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg);
  padding: 6px;
  gap: 4px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
  z-index: 4;
}

.canvas-controls .control-btn {
  width: 34px;
  height: 34px;
  border-radius: var(--border-radius-md);
  border: none;
  background-color: transparent;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text-secondary);
  transition: all var(--transition-fast);
}

.canvas-controls .control-btn:hover {
  background-color: var(--bg-card-hover);
  color: var(--accent-color);
}

.zoom-level {
  font-family: var(--font-family-display);
  font-size: 12px;
  font-weight: 600;
  padding: 0 10px;
  min-width: 50px;
  text-align: center;
  color: var(--text-secondary);
}

/* Floating Node Control Menu */
.node-menu {
  position: absolute;
  background-color: var(--bg-sidebar);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-md);
  padding: 4px;
  display: flex;
  gap: 2px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
  transform: translate(-50%, -100%);
  margin-top: -12px;
  pointer-events: auto;
  z-index: 100;
  animation: popIn var(--transition-fast);
}

.node-menu-btn {
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 6px 10px;
  border: none;
  background-color: transparent;
  font-size: 12px;
  font-weight: 500;
  border-radius: var(--border-radius-sm);
  cursor: pointer;
  color: var(--text-secondary);
  transition: all var(--transition-fast);
}

.node-menu-btn:hover {
  background-color: var(--bg-card-hover);
  color: var(--text-primary);
}

.node-menu-btn.add-btn:hover { color: #10b981; }
.node-menu-btn.sibling-btn:hover { color: #3b82f6; }
.node-menu-btn.edit-btn:hover { color: #f59e0b; }
.node-menu-btn.delete-btn:hover { color: #ef4444; }

/* Inline Node Editor Input */
.inline-node-editor {
  position: absolute;
  background-color: var(--bg-input);
  border: 2px solid var(--accent-color);
  border-radius: var(--border-radius-sm);
  color: var(--text-primary);
  font-size: 13px;
  font-weight: 500;
  padding: 4px 8px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
  z-index: 101;
  text-align: center;
}

/* Dropdowns */
.dropdown {
  position: relative;
  display: inline-block;
}

.dropdown-content {
  display: none;
  position: absolute;
  right: 0;
  top: calc(100% + 8px);
  background-color: var(--bg-sidebar);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  min-width: 200px;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-md);
  z-index: 20;
  padding: 6px;
  transform-origin: top right;
  animation: dropShow var(--transition-fast);
}

.theme-dropdown-content {
  min-width: 220px;
}

.theme-dot {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  display: inline-block;
  flex-shrink: 0;
  box-shadow: inset 0 0 2px rgba(0,0,0,0.2);
}

.dropdown-content.show {
  display: block;
}

.dropdown-content a {
  color: var(--text-secondary);
  padding: 10px 14px;
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 12px;
  border-radius: var(--border-radius-sm);
  font-size: 13px;
  font-weight: 500;
  transition: all var(--transition-fast);
}

.dropdown-content a:hover {
  background-color: var(--bg-card-hover);
  color: var(--text-primary);
}

.dropdown-content .icon {
  font-size: 16px;
}

/* Drag and Drop Overlay */
.drop-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(9, 13, 22, 0.85);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 900;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-normal);
}

.drop-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

.drop-box {
  width: calc(100% - 48px);
  max-width: 480px;
  padding: 40px;
  border: 2px dashed var(--accent-color);
  border-radius: var(--border-radius-lg);
  text-align: center;
  background-color: rgba(13, 20, 35, 0.6);
  transform: scale(0.9);
  transition: transform var(--transition-normal);
}

.drop-overlay.active .drop-box {
  transform: scale(1);
}

.drop-icon {
  color: var(--accent-color);
  margin-bottom: 20px;
  animation: bounce 2s infinite;
}

.drop-box h3 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.drop-box p {
  font-size: 14px;
  color: var(--text-secondary);
}

/* ==========================================================================
   SVG Node and Link Graphics
   ========================================================================== */

.mindmap-node {
  cursor: pointer;
  transition: transform var(--transition-fast);
}

.mindmap-node rect {
  fill: var(--node-bg);
  stroke: var(--node-border-default);
  stroke-width: 1.5;
  rx: 8px;
  ry: 8px;
  filter: url(#node-shadow);
  transition: fill var(--transition-fast), stroke var(--transition-fast), stroke-width var(--transition-fast);
}

.mindmap-node:hover rect {
  fill: var(--bg-card-hover);
  stroke-width: 2;
  filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.25));
}

.mindmap-node.root-node rect {
  fill: var(--node-root-bg);
  stroke: none;
  rx: 12px;
  ry: 12px;
}

.mindmap-node.selected rect {
  stroke: var(--accent-color);
  stroke-width: 2.5;
  filter: url(#active-shadow);
}

.mindmap-node text {
  fill: var(--node-text);
  font-size: 13px;
  font-weight: 500;
  pointer-events: none;
  user-select: none;
  text-anchor: middle;
  dominant-baseline: middle;
}

.mindmap-node.root-node text {
  fill: var(--node-root-text);
  font-family: var(--font-family-display);
  font-size: 15px;
  font-weight: 700;
}

.mindmap-node.depth-1 text {
  font-weight: 600;
}

.mindmap-link {
  fill: none;
  stroke-width: 2;
  stroke-linecap: round;
  transition: stroke var(--transition-normal), stroke-width var(--transition-fast);
}

/* Collapse / Expand toggle button in SVG */
.collapse-toggle {
  cursor: pointer;
  transition: transform var(--transition-fast);
}

.collapse-toggle:hover {
  transform: scale(1.2);
}

.collapse-toggle circle {
  fill: var(--bg-input);
  stroke: var(--accent-color);
  stroke-width: 1.5;
}

.collapse-toggle line {
  stroke: var(--accent-color);
  stroke-width: 1.5;
  stroke-linecap: round;
}

/* ==========================================================================
   Animations
   ========================================================================== */

@keyframes popIn {
  0% { transform: translate(-50%, -90%) scale(0.9); opacity: 0; }
  100% { transform: translate(-50%, -100%) scale(1); opacity: 1; }
}

@keyframes dropShow {
  0% { transform: scale(0.95); opacity: 0; }
  100% { transform: scale(1); opacity: 1; }
}

@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

/* ==========================================================================
   Responsive / Mobile Optimization
   ========================================================================== */

@media (max-width: 768px) {
  .sidebar {
    position: absolute;
    left: 0;
    top: 0;
    width: 85vw;
    height: 100%;
    z-index: 100;
    box-shadow: 10px 0 30px rgba(0, 0, 0, 0.4);
    margin-left: 0;
    transition: transform var(--transition-normal);
  }
  
  .sidebar.collapsed {
    transform: translateX(-100%);
    margin-left: 0;
  }
  
  .topbar {
    padding: 0 16px;
    height: 56px;
  }
  
  .app-title {
    font-size: 16px;
  }
  
  .topbar-actions .action-btn span {
    display: none; /* Hide text on mobile for small buttons */
  }
  
  .topbar-actions .action-btn {
    padding: 8px;
    width: 38px;
    justify-content: center;
  }
  
  .topbar-actions {
    gap: 6px;
  }
  
  .canvas-controls {
    bottom: 16px;
    right: 16px;
  }
}