@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Outfit:wght@400;500;600;700;800&display=swap');

/* ==========================================
   1. Dynamic CSS Variables & Theming System
   ========================================== */
:root {
  /* Common Accent Colors (Linear & Duolingo Infused) */
  --accent-indigo: #4f46e5;
  --accent-indigo-glow: rgba(79, 70, 229, 0.25);
  --color-primary: #5850ec;
  --color-cyan: #06b6d4;      /* DSA Cyan */
  --color-purple: #8b5cf6;    /* HLD Purple */
  --color-emerald: #10b981;   /* LLD/Completed Emerald */
  --color-amber: #f59e0b;     /* In-Progress Amber */
  --color-rose: #f43f5e;      /* Hard Rose */
  --color-slate: #6b7280;

  /* Dark Theme Tokens (Default - Raycast / Linear Inspired) */
  --bg-app: #08090c;
  --bg-sidebar: #0e1015;
  --bg-card: #13161c;
  --bg-card-hover: #191d25;
  --bg-input: #0b0c0f;
  --border-color: rgba(255, 255, 255, 0.05);
  --border-hover: rgba(255, 255, 255, 0.12);
  --border-active: rgba(79, 70, 229, 0.4);
  
  --text-main: #f3f4f6;
  --text-muted: #9ca3af;
  --text-dark: #4b5563;
  --text-white: #ffffff;
  
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.5);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.6);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.8);
  --shadow-glow: 0 0 20px rgba(79, 70, 229, 0.15);

  --font-display: 'Outfit', sans-serif;
  --font-body: 'Inter', sans-serif;
  --transition-normal: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-bounce: 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
  
  /* Heatmap Dark Grid */
  --heatmap-empty: #1c2128;
  --heatmap-l1: #2e3a5f;
  --heatmap-l2: #4a5da6;
  --heatmap-l3: #5850ec;
}

/* Light Theme Tokens (Notion / Stripe Dashboard Infused) */
.light-mode {
  --bg-app: #f6f8fa;
  --bg-sidebar: #ffffff;
  --bg-card: #ffffff;
  --bg-card-hover: #fcfdfe;
  --bg-input: #f1f3f5;
  --border-color: #e1e4e8;
  --border-hover: #cfd3db;
  --border-active: rgba(79, 70, 229, 0.6);
  
  --text-main: #1f2328;
  --text-muted: #57606a;
  --text-dark: #959da5;
  --text-white: #ffffff;
  
  --shadow-sm: 0 1px 3px rgba(27, 31, 35, 0.08);
  --shadow-md: 0 4px 12px rgba(27, 31, 35, 0.08);
  --shadow-lg: 0 8px 24px rgba(27, 31, 35, 0.12);
  --shadow-glow: 0 0 20px rgba(79, 70, 229, 0.1);
  
  /* Heatmap Light Grid */
  --heatmap-empty: #ebedf0;
  --heatmap-l1: #c6dbef;
  --heatmap-l2: #6baed6;
  --heatmap-l3: #5850ec;
}

/* ==========================================
   2. Base Resets & Typography
   ========================================== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html, body {
  min-height: 100vh;
  background: var(--bg-app);
  color: var(--text-main);
  font-family: var(--font-body);
  transition: background-color var(--transition-normal);
  scroll-behavior: smooth;
}

/* Custom premium scrollbar */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 99px;
  transition: background var(--transition-normal);
}
::-webkit-scrollbar-thumb:hover {
  background: var(--border-hover);
}

/* Glassmorphism Sidebar Utility */
.glass-panel {
  background: var(--bg-sidebar);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  box-shadow: var(--shadow-sm);
  transition: border var(--transition-normal), box-shadow var(--transition-normal);
}

/* ==========================================
   3. Application Grid Layout
   ========================================== */
.app-container {
  display: grid;
  grid-template-columns: 340px 1fr;
  grid-template-areas: "sidebar main";
  height: 100vh;
  overflow: hidden;
}

/* ==========================================
   4. Sidebar Panel Styling (Left Panel)
   ========================================== */
.sidebar-panel {
  grid-area: sidebar;
  background: var(--bg-sidebar);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow-y: auto;
  padding: 30px 24px;
  gap: 32px;
}

/* Brand Logo Section */
.brand-section {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.brand-section h2 {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  color: var(--text-main);
}

.brand-section p {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* Circular Overall Progress Block */
.progress-section {
  display: flex;
  align-items: center;
  gap: 20px;
  background: rgba(120, 120, 255, 0.02);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  padding: 18px;
}

.progress-circle-container {
  position: relative;
  width: 76px;
  height: 76px;
}

.progress-circle-bg {
  fill: none;
  stroke: var(--border-color);
  stroke-width: 6;
}

.progress-circle-bar {
  fill: none;
  stroke: var(--color-primary);
  stroke-width: 6;
  stroke-linecap: round;
  stroke-dasharray: 339.29; /* 2 * PI * r = 2 * 3.14159 * 54 */
  stroke-dashoffset: 339.29;
  transform: rotate(-90deg);
  transform-origin: 50% 50%;
  transition: stroke-dashoffset 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}

.progress-text {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  text-align: center;
}

.progress-percentage {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--text-main);
}

.progress-info-box {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.progress-info-title {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-main);
}

.progress-info-subtitle {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* Sidebar Categories Filter Links */
.filters-section {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.filters-title {
  font-family: var(--font-display);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-dark);
  letter-spacing: 1px;
  margin-bottom: 4px;
}

.filter-btn {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 8px 12px;
  background: transparent;
  border: none;
  border-radius: 8px;
  color: var(--text-muted);
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-normal);
}

.filter-btn-left {
  display: flex;
  align-items: center;
  gap: 10px;
}

.filter-btn i {
  font-size: 0.95rem;
}

.filter-btn:hover {
  background: var(--bg-input);
  color: var(--text-main);
}

.filter-btn.active {
  background: var(--color-primary);
  color: var(--text-white);
}

.filter-count {
  font-size: 0.75rem;
  background: rgba(0, 0, 0, 0.15);
  padding: 2px 6px;
  border-radius: 6px;
  color: var(--text-muted);
}

.filter-btn.active .filter-count {
  background: rgba(255, 255, 255, 0.2);
  color: var(--text-white);
}

/* Badge Showcase in Sidebar (Duolingo Style Gamification) */
.badges-section {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.badges-grid {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.badge-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  transition: all var(--transition-bounce);
}

.badge-icon-box {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-dark);
}

.badge-info {
  display: flex;
  flex-direction: column;
  gap: 1px;
}

.badge-title {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
}

.badge-desc {
  font-size: 0.68rem;
  color: var(--text-dark);
}

/* Active Achievement Badge Glowing Gradients */
.badge-item.unlocked {
  background: var(--bg-card-hover);
  border-color: var(--border-hover);
}

.badge-item.unlocked .badge-title {
  color: var(--text-main);
}

.badge-item.unlocked .badge-desc {
  color: var(--text-muted);
}

/* Unlock Glow Classes */
.badge-glow-fire .badge-icon-box { background: rgba(245, 158, 11, 0.12); color: var(--color-amber); box-shadow: 0 0 10px rgba(245, 158, 11, 0.2); }
.badge-glow-cyan .badge-icon-box { background: rgba(6, 182, 212, 0.12); color: var(--color-cyan); box-shadow: 0 0 10px rgba(6, 182, 212, 0.2); }
.badge-glow-purple .badge-icon-box { background: rgba(139, 92, 246, 0.12); color: var(--color-purple); box-shadow: 0 0 10px rgba(139, 92, 246, 0.2); }
.badge-glow-emerald .badge-icon-box { background: rgba(16, 185, 129, 0.12); color: var(--color-emerald); box-shadow: 0 0 10px rgba(16, 185, 129, 0.2); }
.badge-glow-rose .badge-icon-box { background: rgba(244, 63, 94, 0.12); color: var(--color-rose); box-shadow: 0 0 10px rgba(244, 63, 94, 0.2); }
.badge-glow-amber .badge-icon-box { background: rgba(245, 158, 11, 0.12); color: var(--color-amber); box-shadow: 0 0 10px rgba(245, 158, 11, 0.2); }

.badge-item.locked {
  opacity: 0.55;
  filter: grayscale(1);
}

.badge-item:hover {
  transform: scale(1.02);
}

/* ==========================================
   5. Main Scroll Panel Styling
   ========================================== */
.main-panel {
  grid-area: main;
  display: flex;
  flex-direction: column;
  overflow-y: auto;
  height: 100vh;
}

/* Sticky Top Navigation Bar */
.top-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 40px;
  background: rgba(8, 9, 12, 0.6);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 50;
  transition: background-color var(--transition-normal);
}

.light-mode .top-nav {
  background: rgba(246, 248, 250, 0.8);
}

.top-nav-left {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.current-date {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.top-nav-left h1 {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-main);
}

.top-nav-right {
  display: flex;
  align-items: center;
  gap: 16px;
}

/* Search Box element */
.search-wrapper {
  position: relative;
  width: 260px;
}

.search-wrapper input {
  width: 100%;
  padding: 8px 12px 8px 36px;
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  color: var(--text-main);
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 500;
  transition: all var(--transition-normal);
}

.search-wrapper input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.15);
}

.search-wrapper i {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* Dark/Light mode Switcher Toggle */
.theme-toggle-btn {
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  width: 36px;
  height: 36px;
  border-radius: 8px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.95rem;
  transition: all var(--transition-normal);
}

.theme-toggle-btn:hover {
  background: var(--border-color);
  border-color: var(--text-muted);
}

/* Dashboard Scrollable Body Container */
.dashboard-body {
  padding: 40px;
  display: flex;
  flex-direction: column;
  gap: 32px;
  max-width: 1080px;
  width: 100%;
  margin: 0 auto;
}

/* Header Statistics Dashboard Indicators Row */
.header-stats-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  position: relative;
  overflow: hidden;
}

.stat-card-icon {
  position: absolute;
  right: 16px;
  top: 16px;
  font-size: 1.15rem;
  color: var(--text-dark);
}

.stat-card span {
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  color: var(--text-muted);
  letter-spacing: 0.5px;
}

.stat-card h3 {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-main);
}

/* ==========================================
   6. Today's Focus Card (Today's Mission)
   ========================================== */
.today-mission-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 28px;
  display: flex;
  flex-direction: column;
  gap: 20px;
  position: relative;
  box-shadow: var(--shadow-sm);
  transition: border var(--transition-normal), box-shadow var(--transition-normal);
}

.today-mission-card::before {
  content: '';
  position: absolute;
  top: -1px;
  left: 20px;
  right: 20px;
  height: 2px;
  background: linear-gradient(90deg, var(--color-cyan), var(--color-primary), var(--color-purple));
  border-radius: 99px;
}

.mission-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
}

.mission-header-left {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.mission-day-pill {
  font-family: var(--font-display);
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  background: rgba(79, 70, 229, 0.1);
  color: var(--color-primary);
  border: 1px solid rgba(79, 70, 229, 0.2);
  padding: 3px 8px;
  border-radius: 6px;
  align-self: flex-start;
}

.mission-header-left h2 {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-main);
}

.mission-status-metric {
  font-family: var(--font-display);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-muted);
  background: var(--bg-input);
  padding: 6px 12px;
  border-radius: 8px;
  border: 1px solid var(--border-color);
}

/* Mission Progress Bar */
.mission-progress-bar {
  width: 100%;
  height: 6px;
  background: var(--bg-input);
  border-radius: 99px;
  overflow: hidden;
}

.mission-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--color-cyan) 0%, var(--color-primary) 100%);
  width: 0;
  border-radius: 99px;
  transition: width 0.6s cubic-bezier(0.1, 0.8, 0.3, 1);
}

/* Mission Grid List */
.mission-topics-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.mission-topic-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 14px 18px;
  cursor: pointer;
  transition: all var(--transition-normal);
}

.mission-topic-item:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-hover);
  transform: translateX(4px);
}

.mission-topic-left {
  display: flex;
  align-items: center;
  gap: 14px;
}

/* Checklist Checkbox */
.mission-checkbox, .status-toggle {
  background: transparent;
  border: none;
  font-size: 1.25rem;
  color: var(--text-dark);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color var(--transition-normal), transform 0.15s ease;
}

.mission-checkbox:hover, .status-toggle:hover {
  transform: scale(1.1);
  color: var(--text-muted);
}

.mission-topic-item.completed .mission-checkbox,
.topic-item.completed .status-toggle {
  color: var(--color-emerald);
}

.mission-topic-item.in_progress .mission-checkbox,
.topic-item.in_progress .status-toggle {
  color: var(--color-amber);
}

.mission-topic-title {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-main);
}

.mission-topic-item.completed .mission-topic-title {
  text-decoration: line-through;
  color: var(--text-dark);
}

.mission-topic-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* Stopwatch Time Indicator */
.mission-time, .time-duration {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 6px;
}

.mission-focus-btn {
  background: rgba(79, 70, 229, 0.08);
  border: 1px solid rgba(79, 70, 229, 0.15);
  color: var(--color-primary);
  font-family: var(--font-body);
  font-size: 0.7rem;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 6px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 4px;
  transition: all var(--transition-normal);
}

.mission-focus-btn:hover {
  background: var(--color-primary);
  color: white;
  border-color: var(--color-primary);
}

.pomodoro-card.break-mode .mission-focus-btn:hover {
  background: var(--color-emerald);
  border-color: var(--color-emerald);
}

/* Difficulty Indicators */
.diff-pill {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  padding: 2px 8px;
  border-radius: 4px;
  letter-spacing: 0.5px;
}

.diff-easy { background: rgba(16, 185, 129, 0.1); color: var(--color-emerald); }
.diff-medium { background: rgba(245, 158, 11, 0.1); color: var(--color-amber); }
.diff-hard { background: rgba(244, 63, 94, 0.1); color: var(--color-rose); }

.mission-footer-hint {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* ==========================================
   7. Heatmap & Analytics Block
   ========================================== */
.analytics-heatmap-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 24px;
  display: grid;
  grid-template-columns: 2fr 1.3fr;
  gap: 32px;
}

.heatmap-wrapper {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.analytics-title {
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-muted);
  letter-spacing: 0.5px;
  display: flex;
  align-items: center;
  gap: 8px;
}

/* GitHub Heatmap Grid Structure */
.heatmap-container {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.heatmap-grid {
  display: grid;
  grid-template-rows: repeat(7, 10px);
  grid-auto-flow: column;
  gap: 3px;
  align-self: flex-start;
}

.heatmap-cell {
  width: 10px;
  height: 10px;
  border-radius: 2px;
  background: var(--heatmap-empty);
  transition: transform var(--transition-normal), background var(--transition-normal);
  cursor: pointer;
}

.heatmap-cell:hover {
  transform: scale(1.3);
  z-index: 10;
}

/* Color densities */
.heatmap-cell.level-0 { background: var(--heatmap-empty); }
.heatmap-cell.level-1 { background: var(--heatmap-l1); }
.heatmap-cell.level-2 { background: var(--heatmap-l2); }
.heatmap-cell.level-3 { background: var(--heatmap-l3); }

/* Legend Row */
.heatmap-legend {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 4px;
  font-size: 0.68rem;
  color: var(--text-dark);
  margin-top: 4px;
  padding-right: 20px;
}

.quote-encourager-column {
  border-left: 1px solid var(--border-color);
  padding-left: 32px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 16px;
}

/* Quote Layout */
.quote-container {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.quote-text {
  font-size: 0.88rem;
  font-style: italic;
  line-height: 1.5;
  color: var(--text-main);
  font-weight: 500;
}

.quote-author {
  font-size: 0.72rem;
  color: var(--text-muted);
  font-weight: 600;
}

.streak-encourager {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-amber);
  display: flex;
  align-items: center;
  gap: 8px;
}

/* ==========================================
   8. Syllabus Timeline Scroll Panel
   ========================================== */
.timeline-section-header {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 4px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.timeline-container {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.day-card {
  padding: 24px 28px;
  border-radius: 16px;
  position: relative;
  overflow: hidden;
}

/* Border highlighting based on active status */
.day-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--border-color);
  transition: background var(--transition-normal);
}

.day-card.completed::before { background: var(--color-emerald); }
.day-card.in-progress::before { background: var(--color-amber); }
.day-card.active-day::before { background: var(--color-primary); }

.day-card.active-day {
  border-color: var(--border-active);
  box-shadow: var(--shadow-glow);
}

.day-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}

.day-title-wrapper {
  display: flex;
  align-items: center;
  gap: 14px;
}

.day-number {
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 800;
  background: var(--bg-input);
  color: var(--text-main);
  padding: 4px 10px;
  border-radius: 6px;
  border: 1px solid var(--border-color);
}

.day-card.active-day .day-number {
  background: rgba(79, 70, 229, 0.1);
  color: var(--color-primary);
  border-color: rgba(79, 70, 229, 0.2);
}

.day-title {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-main);
}

.day-progress-bar-container {
  display: flex;
  align-items: center;
  gap: 10px;
}

.day-progress-val {
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--text-muted);
}

.day-progress-bar {
  width: 100px;
  height: 4px;
  background: var(--bg-input);
  border-radius: 99px;
  overflow: hidden;
}

.day-progress-fill {
  height: 100%;
  background: var(--color-emerald);
  width: 0%;
  transition: width 0.5s ease-in-out;
}

/* Cards Grid inside day */
.topics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
}

.topic-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 18px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  cursor: pointer;
  position: relative;
  transition: all var(--transition-normal);
}

.topic-item:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.topic-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 8px;
}

.topic-title-box {
  display: flex;
  flex-direction: column;
  gap: 6px;
  flex: 1;
}

.topic-title {
  font-size: 0.88rem;
  font-weight: 600;
  line-height: 1.4;
  color: var(--text-main);
}

.topic-item.completed .topic-title {
  text-decoration: line-through;
  color: var(--text-dark);
}

.topic-meta-row {
  display: flex;
  align-items: center;
  gap: 10px;
}

.topic-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: auto;
  border-top: 1px solid var(--border-color);
  padding-top: 10px;
}

.topic-tags {
  display: flex;
  gap: 4px;
}

.badge {
  font-size: 0.65rem;
  font-weight: 600;
  padding: 2px 6px;
  border-radius: 4px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.badge-dsa { background: rgba(6, 182, 212, 0.1); color: var(--color-cyan); border: 1px solid rgba(6, 182, 212, 0.15); }
.badge-hld { background: rgba(139, 92, 246, 0.1); color: var(--color-purple); border: 1px solid rgba(139, 92, 246, 0.15); }
.badge-lld { background: rgba(16, 185, 129, 0.1); color: var(--color-emerald); border: 1px solid rgba(16, 185, 129, 0.15); }
.badge-tag { background: var(--bg-input); color: var(--text-muted); border: 1px solid var(--border-color); }

.notes-indicator {
  font-size: 0.75rem;
  color: var(--text-dark);
}

.topic-item.has-notes .notes-indicator {
  color: var(--color-primary);
}

/* ==========================================
   9. Slide-out Cheatsheet Detail Drawer
   ========================================== */
.detail-drawer {
  position: fixed;
  top: 0;
  right: -560px;
  width: 540px;
  height: 100vh;
  background: var(--bg-sidebar);
  border-left: 1px solid var(--border-color);
  box-shadow: var(--shadow-lg);
  z-index: 100;
  display: flex;
  flex-direction: column;
  transition: right 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.detail-drawer.open {
  right: 0;
}

.drawer-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0, 0, 0, 0.4);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 99;
  display: none;
}

.drawer-backdrop.open {
  display: block;
}

.drawer-header {
  padding: 24px 30px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.drawer-title-area {
  display: flex;
  flex-direction: column;
  gap: 8px;
  flex: 1;
}

.drawer-title {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text-main);
}

.close-drawer-btn {
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  font-size: 1.2rem;
  cursor: pointer;
  width: 36px;
  height: 36px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-normal);
}

.close-drawer-btn:hover {
  background: var(--border-color);
  color: var(--text-main);
}

.drawer-body {
  flex: 1;
  overflow-y: auto;
  padding: 30px;
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.cheatsheet-section {
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 20px;
}

.cheatsheet-section h3 {
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 14px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 6px;
}

.cheatsheet-content {
  font-size: 0.92rem;
  line-height: 1.6;
  color: var(--text-main);
}

.cheatsheet-content h3 {
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--color-primary);
  margin-top: 20px;
  margin-bottom: 8px;
  border: none;
  padding-bottom: 0;
}

.cheatsheet-content h3:first-of-type {
  margin-top: 0;
}

.cheatsheet-content p {
  margin-bottom: 12px;
}

.cheatsheet-content ul {
  padding-left: 20px;
  margin-bottom: 12px;
}

.cheatsheet-content li {
  margin-bottom: 6px;
}

.cheatsheet-content code {
  background: rgba(120, 120, 255, 0.08);
  font-family: 'Courier New', Courier, monospace;
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.8rem;
  color: var(--color-primary);
}

.cheatsheet-content pre {
  background: #0f1115;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 12px;
  overflow-x: auto;
  margin-bottom: 12px;
}

.cheatsheet-content pre code {
  background: transparent;
  padding: 0;
  font-size: 0.78rem;
  color: #a5b4fc;
}

/* User Notes inside Drawer */
.notes-section {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.notes-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.notes-title {
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 8px;
}

.notes-status-select {
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 6px 12px;
  border-radius: 8px;
  font-size: 0.8rem;
  outline: none;
  cursor: pointer;
}

.notes-status-select:focus {
  border-color: var(--color-primary);
}

.notes-textarea {
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 14px;
  color: var(--text-main);
  font-family: var(--font-body);
  font-size: 0.88rem;
  line-height: 1.5;
  resize: vertical;
  min-height: 130px;
  transition: all var(--transition-normal);
}

.notes-textarea:focus {
  outline: none;
  border-color: var(--color-primary);
}

.notes-footer {
  display: flex;
  justify-content: flex-end;
}

.save-notes-btn {
  background: var(--color-primary);
  color: white;
  border: none;
  border-radius: 8px;
  padding: 8px 16px;
  font-family: var(--font-body);
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: all var(--transition-normal);
}

.save-notes-btn:hover {
  opacity: 0.95;
  transform: translateY(-1px);
}

/* ==========================================
   8.5. Pomodoro Focus Timer Widget
   ========================================== */
.pomodoro-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 24px 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  position: relative;
  box-shadow: var(--shadow-sm);
  transition: border var(--transition-normal), box-shadow var(--transition-normal);
}

.pomodoro-card.running {
  border-color: var(--border-active);
  box-shadow: var(--shadow-glow);
}

.pomodoro-left {
  display: flex;
  align-items: center;
  gap: 24px;
  flex: 1;
}

.pomodoro-circle-box {
  position: relative;
  width: 90px;
  height: 90px;
}

.pomodoro-circle-bg {
  fill: none;
  stroke: var(--border-color);
  stroke-width: 6;
}

.pomodoro-circle-bar {
  fill: none;
  stroke: var(--color-primary);
  stroke-width: 6;
  stroke-linecap: round;
  stroke-dasharray: 251.2; /* 2 * PI * r = 2 * 3.14159 * 40 */
  stroke-dashoffset: 251.2;
  transform: rotate(-90deg);
  transform-origin: 50% 50%;
  transition: stroke-dashoffset 0.3s linear, stroke var(--transition-normal);
}

.pomodoro-card.break-mode .pomodoro-circle-bar {
  stroke: var(--color-emerald);
}

.pomodoro-time-display {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--text-main);
}

.pomodoro-details {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.pomodoro-card-title {
  font-family: var(--font-display);
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-muted);
  letter-spacing: 1px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.pomodoro-card.running .pomodoro-card-title i {
  color: var(--color-amber);
  animation: pulse 1.5s infinite;
}

.pomodoro-active-title {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1.3;
}

.pomodoro-active-hint {
  font-size: 0.78rem;
  color: var(--text-dark);
  font-weight: 500;
}

.pomodoro-right {
  display: flex;
  align-items: center;
  gap: 20px;
}

.pomodoro-mode-selector {
  display: flex;
  background: var(--bg-input);
  padding: 4px;
  border-radius: 8px;
  border: 1px solid var(--border-color);
}

.pomodoro-mode-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-family: var(--font-body);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 6px 12px;
  border-radius: 6px;
  cursor: pointer;
  transition: all var(--transition-normal);
}

.pomodoro-mode-btn.active {
  background: var(--bg-card);
  color: var(--text-main);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-color);
}

.pomodoro-card.break-mode .pomodoro-mode-btn.active {
  color: var(--color-emerald);
}

.pomodoro-controls {
  display: flex;
  align-items: center;
  gap: 8px;
}

.pomodoro-control-btn {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  background: var(--bg-input);
  color: var(--text-main);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.95rem;
  transition: all var(--transition-normal);
}

.pomodoro-control-btn:hover {
  background: var(--border-color);
  transform: translateY(-1px);
}

.pomodoro-control-btn.btn-play {
  background: var(--color-primary);
  color: white;
  border-color: var(--color-primary);
}

.pomodoro-control-btn.btn-play:hover {
  opacity: 0.9;
}

.pomodoro-card.break-mode .pomodoro-control-btn.btn-play {
  background: var(--color-emerald);
  border-color: var(--color-emerald);
}

/* Empty State Styling */
.empty-state {
  text-align: center;
  padding: 80px 20px;
  color: var(--text-muted);
  font-family: var(--font-display);
}

.empty-state i {
  font-size: 2.5rem;
  margin-bottom: 16px;
  color: var(--text-dark);
}

.empty-state h3 {
  font-size: 1.15rem;
  margin-bottom: 6px;
  color: var(--text-main);
}

/* ==========================================
   10. Responsiveness Adjustments
   ========================================== */
@media (max-width: 1100px) {
  .analytics-heatmap-card {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  .quote-encourager-column {
    border-left: none;
    padding-left: 0;
    border-top: 1px solid var(--border-color);
    padding-top: 20px;
  }
}

@media (max-width: 992px) {
  .app-container {
    grid-template-columns: 1fr;
    grid-template-areas: "main";
    height: auto;
    overflow: visible;
  }
  
  .sidebar-panel {
    display: none; /* simple sidebar toggle or scroll list in mobile. */
  }

  .main-panel {
    height: auto;
    overflow: visible;
  }

  .top-nav {
    position: static;
    padding: 20px;
  }

  .dashboard-body {
    padding: 20px;
  }

  .header-stats-row {
    grid-template-columns: repeat(2, 1fr);
  }

  .detail-drawer {
    width: 100vw;
    right: -100vw;
  }
}

@media (max-width: 576px) {
  .header-stats-row {
    grid-template-columns: 1fr;
  }
  .search-wrapper {
    width: 160px;
  }
  .top-nav-left h1 {
    font-size: 1.15rem;
  }
}

/* Animations */
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.6; }
}

.animate-pulse {
  animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}