/* Modern Minimal Light Mode Design System - Notion & Linear Aesthetic */

:root {
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --bg-app: #F9FAFB;
  --bg-surface: #FFFFFF;
  --bg-sidebar: #F3F4F6;
  --bg-hover: #F3F4F6;
  --bg-active: #E5E7EB;
  --border-color: #E5E7EB;
  --border-focus: #3B82F6;
  
  --text-primary: #111827;
  --text-secondary: #4B5563;
  --text-muted: #9CA3AF;
  
  --accent-color: #3B82F6;
  --accent-hover: #2563EB;
  --accent-light: #EFF6FF;
  
  --success-color: #10B981;
  --success-bg: #ECFDF5;
  --warning-color: #F59E0B;
  --warning-bg: #FFFBEB;
  --danger-color: #EF4444;
  --danger-bg: #FEF2F2;
  --purple-color: #8B5CF6;
  --purple-bg: #F5F3FF;

  --radius-card: 12px;
  --radius-btn: 8px;
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.05), 0 4px 6px -2px rgba(0, 0, 0, 0.02);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.08), 0 10px 10px -5px rgba(0, 0, 0, 0.03);
}

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

body {
  font-family: var(--font-family);
  background-color: var(--bg-app);
  color: var(--text-primary);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: #D1D5DB;
  border-radius: 9999px;
}
::-webkit-scrollbar-thumb:hover {
  background: #9CA3AF;
}

/* Modern Card Layout */
.card-ui {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-card) !important;
  box-shadow: var(--shadow-sm);
  transition: all 0.2s ease-in-out;
}
.card-ui:hover {
  box-shadow: var(--shadow-md);
  border-color: #D1D5DB;
}

/* Soft Buttons */
.btn-primary {
  background-color: var(--accent-color);
  color: white;
  font-weight: 500;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-btn);
  border: none;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  transition: all 0.15s ease;
}
.btn-primary:hover {
  background-color: var(--accent-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.25);
}

.btn-secondary {
  background-color: var(--bg-surface);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  font-weight: 500;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-btn);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  transition: all 0.15s ease;
}
.btn-secondary:hover {
  background-color: var(--bg-hover);
  border-color: #D1D5DB;
}

/* Tree View Styling */
.tree-node {
  user-select: none;
}
.tree-item-row {
  display: flex;
  align-items: center;
  padding: 0.4rem 0.6rem;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.15s ease;
}
.tree-item-row:hover {
  background-color: var(--bg-hover);
}
.tree-item-row.active {
  background-color: var(--accent-light);
  color: var(--accent-color);
}

/* Progress Circular Ring */
.progress-ring-circle {
  transition: stroke-dashoffset 0.5s ease-in-out;
  transform: rotate(-90deg);
  transform-origin: 50% 50%;
}

/* GitHub Heatmap Grid */
.heatmap-grid {
  display: grid;
  grid-template-rows: repeat(7, 12px);
  grid-auto-flow: column;
  grid-auto-columns: 12px;
  gap: 3px;
  overflow-x: auto;
  padding-bottom: 0.5rem;
}
.heatmap-cell {
  width: 12px;
  height: 12px;
  border-radius: 2px;
  background-color: #EBEDF0;
  transition: transform 0.1s ease;
}
.heatmap-cell:hover {
  transform: scale(1.3);
  z-index: 10;
}
.heatmap-level-0 { background-color: #EBEDF0; }
.heatmap-level-1 { background-color: #9BE9A8; }
.heatmap-level-2 { background-color: #40C463; }
.heatmap-level-3 { background-color: #30A14E; }
.heatmap-level-4 { background-color: #216E39; }

/* Sticky Notes */
.sticky-note {
  border-radius: var(--radius-card);
  padding: 1rem;
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  position: relative;
}
.sticky-note:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* Modal Overlay */
.modal-overlay {
  background: rgba(17, 24, 39, 0.4);
  backdrop-filter: blur(4px);
}

/* Glassmorphism Accents */
.glass-panel {
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  border: 1px solid rgba(229, 231, 235, 0.8);
}