/* ============================================
   Acorn Activity Tracker - Styles
   ============================================ */

/* ========== CSS Variables ========== */
:root {
  /* Colors - Light Mode */
  --color-primary: #6366f1;
  --color-primary-dark: #4f46e5;
  --color-primary-light: #818cf8;
  
  --color-success: #10b981;
  --color-warning: #f59e0b;
  --color-danger: #ef4444;
  --color-info: #3b82f6;
  
  --color-bg: #ffffff;
  --color-bg-secondary: #f9fafb;
  --color-bg-tertiary: #f3f4f6;
  
  --color-text: #111827;
  --color-text-secondary: #6b7280;
  --color-text-tertiary: #9ca3af;
  
  --color-border: #e5e7eb;
  --color-border-light: #f3f4f6;
  
  --color-shadow: rgba(0, 0, 0, 0.1);
  --color-overlay: rgba(0, 0, 0, 0.5);
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  
  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;
  
  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  
  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  
  /* Layout */
  --header-height: 64px;
  --max-width: 1200px;
}

/* Dark Mode */
[data-theme="dark"] {
  --color-bg: #111827;
  --color-bg-secondary: #1f2937;
  --color-bg-tertiary: #374151;
  
  --color-text: #f9fafb;
  --color-text-secondary: #d1d5db;
  --color-text-tertiary: #9ca3af;
  
  --color-border: #374151;
  --color-border-light: #4b5563;
  
  --color-shadow: rgba(0, 0, 0, 0.3);
}

/* ========== Reset & Base ========== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  font-size: var(--font-size-base);
  line-height: 1.5;
  color: var(--color-text);
  background-color: var(--color-bg);
  overflow-x: hidden;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

input, textarea, select {
  font-family: inherit;
  font-size: inherit;
}

svg {
  display: block;
  fill: currentColor;
}

/* ========== App Layout ========== */
.app {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ========== Header ========== */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
}

.header-content {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--spacing-md) var(--spacing-lg);
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-primary);
}

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

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

/* ========== Buttons ========== */
.btn-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
}

.btn-icon:hover {
  background-color: var(--color-bg-tertiary);
  color: var(--color-text);
}

.btn-icon:active {
  transform: scale(0.95);
}

.btn-primary, .btn-secondary, .btn-danger {
  padding: var(--spacing-sm) var(--spacing-lg);
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: var(--font-size-base);
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  transition: all var(--transition-fast);
}

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

.btn-primary:hover {
  background-color: var(--color-primary-dark);
}

.btn-secondary {
  background-color: var(--color-bg-tertiary);
  color: var(--color-text);
}

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

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

.btn-danger:hover {
  background-color: #dc2626;
}

.btn-small {
  padding: var(--spacing-xs) var(--spacing-md);
  font-size: var(--font-size-sm);
}

/* ========== Summary Stats ========== */
.summary {
  max-width: var(--max-width);
  margin: var(--spacing-xl) auto;
  padding: 0 var(--spacing-lg);
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: var(--spacing-md);
}

.summary-card {
  background-color: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  text-align: center;
}

.summary-label {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-xs);
}

.summary-value {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  color: var(--color-primary);
}

/* ========== Main Content ========== */
.main-content {
  flex: 1;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--spacing-lg);
  width: 100%;
}

/* ========== Empty State ========== */
.empty-state {
  text-align: center;
  padding: var(--spacing-2xl) var(--spacing-lg);
  max-width: 400px;
  margin: 0 auto;
  display: block; /* Ensure it's visible by default */
}

.empty-icon {
  color: var(--color-text-tertiary);
  margin: 0 auto var(--spacing-lg);
}

.empty-state h2 {
  font-size: var(--font-size-2xl);
  margin-bottom: var(--spacing-sm);
}

.empty-state p {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-xl);
}

/* ========== Habits Container ========== */
.habits-container {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--spacing-lg);
}

/* ========== Habit Card ========== */
.habit-card {
  background-color: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--spacing-lg);
  transition: all var(--transition-base);
  cursor: pointer;
}

.habit-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.habit-card-header {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-md);
}

.habit-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 24px;
}

.habit-info {
  flex: 1;
  min-width: 0;
}

.habit-name {
  font-size: var(--font-size-lg);
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.habit-description {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.habit-check {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-md);
  border: 2px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
  flex-shrink: 0;
}

.habit-check:hover {
  border-color: var(--color-primary);
}

.habit-check.completed {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: white;
}

.habit-stats {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: var(--spacing-md);
  border-top: 1px solid var(--color-border-light);
  font-size: var(--font-size-sm);
}

.habit-streak {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  color: var(--color-warning);
  font-weight: 600;
}

.habit-frequency {
  color: var(--color-text-secondary);
}

/* ========== Floating Action Button ========== */
.fab {
  position: fixed;
  bottom: var(--spacing-xl);
  right: var(--spacing-xl);
  width: 56px;
  height: 56px;
  border-radius: var(--radius-full);
  background-color: var(--color-primary);
  color: white;
  box-shadow: var(--shadow-xl);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-base);
  z-index: 50;
}

.fab:hover {
  background-color: var(--color-primary-dark);
  transform: scale(1.1);
}

.fab:active {
  transform: scale(0.95);
}

/* ========== Side Menu ========== */
.side-menu {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 200;
  pointer-events: none;
}

.side-menu.open {
  pointer-events: auto;
}

.side-menu-overlay {
  position: absolute;
  inset: 0;
  background-color: var(--color-overlay);
  opacity: 0;
  transition: opacity var(--transition-base);
}

.side-menu.open .side-menu-overlay {
  opacity: 1;
}

.side-menu-content {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  width: 320px;
  max-width: 85vw;
  background-color: var(--color-bg);
  box-shadow: var(--shadow-xl);
  transform: translateX(100%);
  transition: transform var(--transition-base);
  display: flex;
  flex-direction: column;
}

.side-menu.open .side-menu-content {
  transform: translateX(0);
}

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

.side-menu-header h2 {
  font-size: var(--font-size-xl);
}

.menu-list {
  flex: 1;
  list-style: none;
  padding: var(--spacing-md);
  overflow-y: auto;
}

.menu-item {
  width: 100%;
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  font-size: var(--font-size-base);
  color: var(--color-text);
  text-align: left;
  transition: background-color var(--transition-fast);
}

.menu-item:hover {
  background-color: var(--color-bg-tertiary);
}

.menu-footer {
  padding: var(--spacing-lg);
  border-top: 1px solid var(--color-border);
  text-align: center;
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

.version {
  margin-bottom: var(--spacing-xs);
}

/* ========== Modal ========== */
.modal {
  position: fixed;
  inset: 0;
  z-index: 300;
  display: none;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-lg);
}

.modal.open {
  display: flex;
}

.modal-overlay {
  position: absolute;
  inset: 0;
  background-color: var(--color-overlay);
  animation: fadeIn var(--transition-base);
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.modal-content {
  position: relative;
  background-color: var(--color-bg);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  max-width: 500px;
  width: 100%;
  max-height: 90vh;
  display: flex;
  flex-direction: column;
  animation: slideUp var(--transition-base);
}

.modal-large .modal-content {
  max-width: 800px;
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

.modal-header h2 {
  font-size: var(--font-size-2xl);
}

.modal-body {
  flex: 1;
  padding: var(--spacing-lg);
  overflow-y: auto;
}

.modal-footer {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: var(--spacing-md);
  padding: var(--spacing-lg);
  border-top: 1px solid var(--color-border);
}

/* ========== Form Elements ========== */
.form-group {
  margin-bottom: var(--spacing-lg);
}

.form-group label {
  display: block;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
  color: var(--color-text);
}

.form-group input[type="text"],
.form-group input[type="number"],
.form-group textarea,
.form-group select {
  width: 100%;
  padding: var(--spacing-sm) var(--spacing-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background-color: var(--color-bg);
  color: var(--color-text);
  transition: border-color var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--color-primary);
}

.form-group textarea {
  resize: vertical;
}

/* ========== Icon Picker ========== */
.icon-picker {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(48px, 1fr));
  gap: var(--spacing-sm);
}

.icon-option {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  border: 2px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
  font-size: 24px;
}

.icon-option:hover {
  border-color: var(--color-primary);
  transform: scale(1.1);
}

.icon-option.selected {
  border-color: var(--color-primary);
  background-color: var(--color-primary-light);
  color: white;
}

/* ========== Color Picker ========== */
.color-picker {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(40px, 1fr));
  gap: var(--spacing-sm);
}

.color-option {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  border: 3px solid transparent;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.color-option:hover {
  transform: scale(1.15);
}

.color-option.selected {
  border-color: var(--color-text);
  box-shadow: var(--shadow-md);
}

/* ========== Frequency Controls ========== */
.frequency-controls {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.frequency-count {
  width: 80px;
  text-align: center;
}

.frequency-label {
  color: var(--color-text-secondary);
}

/* ========== Reminders ========== */
#reminders-container {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-sm);
}

.reminder-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm);
  background-color: var(--color-bg-secondary);
  border-radius: var(--radius-md);
}

.reminder-item input[type="time"] {
  flex: 1;
}

.reminder-item .btn-icon {
  width: 32px;
  height: 32px;
}

/* ========== Habit Detail ========== */
.habit-detail-header {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-md);
  flex: 1;
}

.habit-icon-large {
  width: 64px;
  height: 64px;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 32px;
  flex-shrink: 0;
}

/* ========== Tabs ========== */
.tabs {
  display: flex;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
  border-bottom: 2px solid var(--color-border);
}

.tab {
  padding: var(--spacing-sm) var(--spacing-lg);
  font-weight: 600;
  color: var(--color-text-secondary);
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
  transition: all var(--transition-fast);
}

.tab:hover {
  color: var(--color-text);
}

.tab.active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
}

/* ========== Streak Info ========== */
.streak-info {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-lg);
  background-color: var(--color-bg-secondary);
  border-radius: var(--radius-lg);
  margin-bottom: var(--spacing-lg);
}

.streak-badge {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--color-warning);
}

.completion-rate {
  color: var(--color-text-secondary);
}

.completion-rate strong {
  color: var(--color-primary);
}

/* ========== Habit Grid ========== */
.habit-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(32px, 1fr));
  gap: var(--spacing-xs);
  max-height: 400px;
  overflow-y: auto;
}

.grid-tile {
  aspect-ratio: 1;
  border-radius: var(--radius-sm);
  background-color: var(--color-bg-tertiary);
  border: 1px solid var(--color-border);
  cursor: pointer;
  transition: all var(--transition-fast);
  position: relative;
}

.grid-tile:hover {
  transform: scale(1.1);
  box-shadow: var(--shadow-sm);
}

.grid-tile.completed {
  background-color: var(--color-success);
  border-color: var(--color-success);
}

.grid-tile.today {
  border: 2px solid var(--color-primary);
}

/* ========== Calendar ========== */
.calendar-controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--spacing-lg);
}

.calendar {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: var(--spacing-xs);
}

.calendar-day {
  aspect-ratio: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  font-size: var(--font-size-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  background-color: var(--color-bg-secondary);
}

.calendar-day:hover:not(.disabled) {
  background-color: var(--color-bg-tertiary);
}

.calendar-day.completed {
  background-color: var(--color-success);
  color: white;
}

.calendar-day.today {
  border: 2px solid var(--color-primary);
}

.calendar-day.disabled {
  opacity: 0.3;
  cursor: not-allowed;
}

.calendar-weekday {
  font-weight: 600;
  color: var(--color-text-secondary);
  text-align: center;
  padding: var(--spacing-sm);
  font-size: var(--font-size-xs);
}

/* ========== Stats ========== */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-xl);
}

.stat-card {
  background-color: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  text-align: center;
}

.stat-label {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-xs);
}

.stat-value {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--color-primary);
}

/* ========== Achievement Badges ========== */
.achievement-badges h4 {
  margin-bottom: var(--spacing-md);
}

.badges {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
  gap: var(--spacing-md);
}

.badge {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md);
  background-color: var(--color-bg-secondary);
  border-radius: var(--radius-lg);
  border: 2px solid var(--color-border);
}

.badge.earned {
  border-color: var(--color-warning);
}

.badge-icon {
  font-size: 32px;
  filter: grayscale(1);
  opacity: 0.4;
}

.badge.earned .badge-icon {
  filter: grayscale(0);
  opacity: 1;
}

.badge-name {
  font-size: var(--font-size-xs);
  color: var(--color-text-secondary);
  text-align: center;
}

/* ========== Toast Notifications ========== */
.toast-container {
  position: fixed;
  bottom: var(--spacing-xl);
  left: 50%;
  transform: translateX(-50%);
  z-index: 400;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  pointer-events: none;
}

.toast {
  background-color: var(--color-text);
  color: var(--color-bg);
  padding: var(--spacing-md) var(--spacing-lg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  min-width: 250px;
  max-width: 400px;
  animation: toastSlideIn var(--transition-base);
  pointer-events: auto;
}

@keyframes toastSlideIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.toast.success {
  background-color: var(--color-success);
}

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

.toast.info {
  background-color: var(--color-info);
}

/* ========== Responsive Design ========== */
@media (max-width: 768px) {
  .habits-container {
    grid-template-columns: 1fr;
  }
  
  .summary {
    grid-template-columns: repeat(3, 1fr);
  }
  
  .habit-grid {
    grid-template-columns: repeat(10, 1fr);
  }
  
  .fab {
    bottom: var(--spacing-lg);
    right: var(--spacing-lg);
  }
}

@media (max-width: 480px) {
  :root {
    --spacing-lg: 1rem;
  }
  
  .header-content {
    padding: var(--spacing-sm) var(--spacing-md);
  }
  
  .logo {
    font-size: var(--font-size-lg);
  }
  
  .summary {
    grid-template-columns: 1fr;
  }
  
  .modal-content {
    max-width: 100%;
    border-radius: 0;
    max-height: 100vh;
  }
  
  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ========== Accessibility ========== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* ========== Print Styles ========== */
@media print {
  .header-actions,
  .fab,
  .side-menu,
  .modal {
    display: none !important;
  }
}