/* ===== CSS Custom Properties ===== */
:root {
  /* Light theme (default) */
  --bg-primary: #FFFFFF;
  --bg-secondary: #F2F2F7;
  --bg-tertiary: #FFFFFF;
  --text-primary: #000000;
  --text-secondary: #8E8E93;
  --text-tertiary: #C7C7CC;
  --separator: #C6C6C8;
  --accent: #007AFF;

  /* Priority colors */
  --priority-none: transparent;
  --priority-low: #007AFF;
  --priority-medium: #FF9500;
  --priority-high: #FF3B30;

  /* List colors */
  --list-red: #FF3B30;
  --list-orange: #FF9500;
  --list-yellow: #FFCC00;
  --list-green: #34C759;
  --list-cyan: #00C7BE;
  --list-blue: #007AFF;
  --list-purple: #5856D6;
  --list-pink: #AF52DE;
  --list-red-secondary: #FF2D55;
  --list-brown: #A2845E;
  --list-gray: #8E8E93;
  --list-black: #000000;

  /* Typography */
  --font-family: -apple-system, BlinkMacSystemFont, 'SF Pro', 'Segoe UI', sans-serif;
  --font-size-large-title: 34px;
  --font-size-title: 22px;
  --font-size-body: 17px;
  --font-size-body-secondary: 16px;
  --font-size-caption: 13px;
  --font-weight-regular: 400;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;

  /* Spacing */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 12px;
  --spacing-lg: 16px;
  --spacing-xl: 20px;
  --spacing-2xl: 24px;

  /* Border radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 999px;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.15);
  --shadow-lg: 0 12px 24px rgba(0, 0, 0, 0.15);
}

/* Dark theme */
@media (prefers-color-scheme: dark) {
  :root {
    --bg-primary: #000000;
    --bg-secondary: #1C1C1E;
    --bg-tertiary: #2C2C2E;
    --text-primary: #FFFFFF;
    --text-secondary: #8E8E93;
    --text-tertiary: #48484A;
    --separator: #38383A;
    --accent: #0A84FF;
  }
}

/* Force dark theme if user preference is set */
[data-theme="dark"] {
  --bg-primary: #000000;
  --bg-secondary: #1C1C1E;
  --bg-tertiary: #2C2C2E;
  --text-primary: #FFFFFF;
  --text-secondary: #8E8E93;
  --text-tertiary: #48484A;
  --separator: #38383A;
  --accent: #0A84FF;
}

/* Force light theme if user preference is set */
[data-theme="light"] {
  --bg-primary: #FFFFFF;
  --bg-secondary: #F2F2F7;
  --bg-tertiary: #FFFFFF;
  --text-primary: #000000;
  --text-secondary: #8E8E93;
  --text-tertiary: #C7C7CC;
  --separator: #C6C6C8;
  --accent: #007AFF;
}

/* ===== Global Styles ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  -webkit-tap-highlight-color: transparent;
}

html, body {
  width: 100%;
  height: 100%;
  font-family: var(--font-family);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  overflow: hidden;
}

body {
  -webkit-user-select: none;
  user-select: none;
}

#root {
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
}

input, textarea, select {
  font-family: var(--font-family);
  color: var(--text-primary);
  background-color: var(--bg-primary);
}

input::placeholder, textarea::placeholder {
  color: var(--text-secondary);
}

/* ===== App Layout ===== */
.app {
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  background-color: var(--bg-primary);
}

.app-content {
  flex: 1;
  display: flex;
  overflow: hidden;
}

/* ===== Sidebar ===== */
.sidebar {
  width: 280px;
  background-color: var(--bg-secondary);
  border-right: 1px solid var(--separator);
  display: flex;
  flex-direction: column;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
}

.sidebar-header {
  padding: var(--spacing-lg);
  border-bottom: 1px solid var(--separator);
}

.sidebar-title {
  font-size: var(--font-size-large-title);
  font-weight: var(--font-weight-bold);
  color: var(--text-primary);
}

.sidebar-section {
  padding: var(--spacing-lg) 0;
  border-bottom: 1px solid var(--separator);
}

.sidebar-section:last-child {
  border-bottom: none;
}

.sidebar-section-title {
  font-size: var(--font-size-caption);
  font-weight: var(--font-weight-semibold);
  color: var(--text-secondary);
  padding: 0 var(--spacing-lg);
  margin-bottom: var(--spacing-md);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.sidebar-item {
  display: flex;
  align-items: center;
  padding: var(--spacing-md) var(--spacing-lg);
  cursor: pointer;
  transition: background-color 150ms ease;
  gap: var(--spacing-md);
  user-select: none;
}

.sidebar-item:active {
  background-color: var(--bg-tertiary);
}

.sidebar-item.active {
  background-color: var(--bg-tertiary);
  border-left: 3px solid var(--accent);
  padding-left: calc(var(--spacing-lg) - 3px);
}

.sidebar-item-icon {
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  flex-shrink: 0;
}

.sidebar-item-text {
  flex: 1;
  font-size: var(--font-size-body);
  color: var(--text-primary);
}

.sidebar-item-badge {
  background-color: var(--accent);
  color: white;
  border-radius: var(--radius-full);
  padding: 2px 6px;
  font-size: 11px;
  font-weight: var(--font-weight-bold);
  flex-shrink: 0;
}

.sidebar-list-item {
  display: flex;
  align-items: center;
  padding: var(--spacing-md) var(--spacing-lg);
  cursor: pointer;
  transition: background-color 150ms ease;
  gap: var(--spacing-md);
  user-select: none;
}

.sidebar-list-item:active {
  background-color: var(--bg-tertiary);
}

.sidebar-list-item.active {
  background-color: var(--bg-tertiary);
  border-left: 3px solid var(--accent);
  padding-left: calc(var(--spacing-lg) - 3px);
}

.sidebar-list-color {
  width: 12px;
  height: 12px;
  border-radius: var(--radius-full);
  flex-shrink: 0;
}

.sidebar-list-name {
  flex: 1;
  font-size: var(--font-size-body);
  color: var(--text-primary);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.sidebar-shared-badge {
  font-size: 11px;
  color: var(--text-secondary);
  flex-shrink: 0;
}

.sidebar-new-list-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-lg);
  margin: var(--spacing-md) var(--spacing-lg) 0;
  background-color: transparent;
  border: none;
  color: var(--accent);
  font-size: var(--font-size-body);
  font-weight: var(--font-weight-semibold);
  cursor: pointer;
  border-radius: var(--radius-md);
  transition: background-color 150ms ease;
}

.sidebar-new-list-btn:active {
  background-color: var(--bg-tertiary);
}

/* ===== Main Content ===== */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

/* ===== View Container ===== */
.view-container {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

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

.view-title {
  font-size: var(--font-size-title);
  font-weight: var(--font-weight-bold);
  color: var(--text-primary);
}

.view-header-actions {
  display: flex;
  gap: var(--spacing-md);
}

.view-content {
  flex: 1;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  padding: var(--spacing-lg);
  background-color: var(--bg-primary);
}

/* ===== List Views ===== */
.reminders-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.reminder-item {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-md);
  padding: var(--spacing-md);
  background-color: var(--bg-secondary);
  border-radius: var(--radius-lg);
  border-left: 3px solid transparent;
  transition: all 150ms ease;
  cursor: pointer;
  user-select: none;
  position: relative;
  overflow: hidden;
}

.reminder-item:active {
  background-color: var(--bg-tertiary);
}

.reminder-item.high-priority {
  border-left-color: var(--priority-high);
}

.reminder-item.medium-priority {
  border-left-color: var(--priority-medium);
}

.reminder-item.low-priority {
  border-left-color: var(--priority-low);
}

.reminder-item.completed {
  opacity: 0.6;
}

.reminder-checkbox {
  width: 32px;
  height: 32px;
  min-width: 32px;
  border: 2px solid var(--separator);
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 150ms ease;
  background-color: var(--bg-primary);
  margin-top: 2px;
}

.reminder-checkbox:active {
  transform: scale(0.95);
}

.reminder-item.completed .reminder-checkbox {
  background-color: var(--accent);
  border-color: var(--accent);
}

.reminder-checkbox-check {
  width: 20px;
  height: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 14px;
  font-weight: var(--font-weight-bold);
}

.reminder-content {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.reminder-title {
  font-size: var(--font-size-body);
  font-weight: var(--font-weight-semibold);
  color: var(--text-primary);
  word-break: break-word;
}

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

.reminder-meta {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: var(--font-size-caption);
  color: var(--text-secondary);
  flex-wrap: wrap;
}

.reminder-due-date {
  display: flex;
  align-items: center;
  gap: 4px;
}

.reminder-due-date.overdue {
  color: var(--priority-high);
  font-weight: var(--font-weight-semibold);
}

.reminder-due-date.today {
  color: var(--accent);
  font-weight: var(--font-weight-semibold);
}

/* ===== Empty State ===== */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-2xl);
  text-align: center;
  color: var(--text-secondary);
}

.empty-state-icon {
  font-size: 64px;
  margin-bottom: var(--spacing-lg);
  opacity: 0.5;
}

.empty-state-title {
  font-size: var(--font-size-title);
  font-weight: var(--font-weight-semibold);
  color: var(--text-primary);
  margin-bottom: var(--spacing-md);
}

.empty-state-text {
  font-size: var(--font-size-body);
  color: var(--text-secondary);
  max-width: 300px;
}

/* ===== Grouped Reminders ===== */
.reminder-group {
  margin-bottom: var(--spacing-lg);
}

.reminder-group-title {
  font-size: var(--font-size-caption);
  font-weight: var(--font-weight-semibold);
  color: var(--text-secondary);
  padding: var(--spacing-md) 0;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.reminder-group-items {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

/* ===== Add Reminder ===== */
.add-reminder-container {
  padding: var(--spacing-lg);
  border-top: 1px solid var(--separator);
  background-color: var(--bg-primary);
  display: flex;
  gap: var(--spacing-md);
}

.add-reminder-input {
  flex: 1;
  padding: var(--spacing-md) var(--spacing-lg);
  background-color: var(--bg-secondary);
  border: none;
  border-radius: var(--radius-lg);
  font-size: var(--font-size-body);
  color: var(--text-primary);
  outline: none;
  transition: background-color 150ms ease;
}

.add-reminder-input:focus {
  background-color: var(--bg-tertiary);
}

.add-reminder-btn {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--accent);
  border: none;
  border-radius: var(--radius-lg);
  color: white;
  cursor: pointer;
  font-size: 18px;
  transition: opacity 150ms ease;
}

.add-reminder-btn:active {
  opacity: 0.7;
}

.add-reminder-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ===== Modal / Sheet ===== */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.3);
  z-index: 1000;
  animation: fadeIn 200ms ease;
}

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

.modal {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background-color: var(--bg-primary);
  border-radius: var(--radius-xl) var(--radius-xl) 0 0;
  padding: var(--spacing-lg);
  max-height: 90vh;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  z-index: 1001;
  animation: slideUp 300ms ease;
  display: flex;
  flex-direction: column;
}

@keyframes slideUp {
  from {
    transform: translateY(100%);
  }
  to {
    transform: translateY(0);
  }
}

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

.modal-title {
  font-size: var(--font-size-title);
  font-weight: var(--font-weight-bold);
  color: var(--text-primary);
}

.modal-close-btn {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: transparent;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 20px;
  transition: color 150ms ease;
}

.modal-close-btn:active {
  color: var(--text-primary);
}

.modal-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
}

.modal-footer {
  display: flex;
  gap: var(--spacing-md);
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--separator);
}

/* ===== Form Elements ===== */
.form-group {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.form-label {
  font-size: var(--font-size-body);
  font-weight: var(--font-weight-semibold);
  color: var(--text-primary);
}

.form-input,
.form-textarea,
.form-select {
  padding: var(--spacing-md) var(--spacing-lg);
  background-color: var(--bg-secondary);
  border: 1px solid var(--separator);
  border-radius: var(--radius-lg);
  font-size: var(--font-size-body);
  color: var(--text-primary);
  outline: none;
  transition: all 150ms ease;
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
  background-color: var(--bg-tertiary);
  border-color: var(--accent);
}

.form-textarea {
  resize: none;
  min-height: 80px;
  font-family: var(--font-family);
}

.form-textarea:focus {
  min-height: 120px;
}

/* ===== Color Picker ===== */
.color-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: var(--spacing-md);
}

.color-option {
  width: 100%;
  aspect-ratio: 1;
  border-radius: var(--radius-lg);
  border: 3px solid transparent;
  cursor: pointer;
  transition: all 150ms ease;
}

.color-option:active {
  transform: scale(0.95);
}

.color-option.selected {
  border-color: var(--text-primary);
  box-shadow: 0 0 0 2px var(--bg-primary), 0 0 0 4px var(--accent);
}

/* ===== Icon Picker ===== */
.icon-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: var(--spacing-md);
}

.icon-option {
  width: 100%;
  aspect-ratio: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 32px;
  border-radius: var(--radius-lg);
  background-color: var(--bg-secondary);
  border: 2px solid transparent;
  cursor: pointer;
  transition: all 150ms ease;
}

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

.icon-option.selected {
  background-color: var(--accent);
  border-color: var(--accent);
}

/* ===== Button Styles ===== */
button {
  font-family: var(--font-family);
}

.btn {
  padding: var(--spacing-md) var(--spacing-lg);
  border: none;
  border-radius: var(--radius-lg);
  font-size: var(--font-size-body);
  font-weight: var(--font-weight-semibold);
  cursor: pointer;
  transition: all 150ms ease;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
}

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

.btn-primary:active {
  opacity: 0.7;
}

.btn-primary:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-secondary {
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  border: 1px solid var(--separator);
}

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

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

.btn-danger:active {
  opacity: 0.7;
}

.btn-full {
  width: 100%;
}

/* ===== Segmented Control ===== */
.segmented-control {
  display: flex;
  background-color: var(--bg-secondary);
  border-radius: var(--radius-lg);
  padding: 4px;
  gap: 4px;
}

.segmented-option {
  flex: 1;
  padding: var(--spacing-md) var(--spacing-lg);
  background-color: transparent;
  border: none;
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-size: var(--font-size-body-secondary);
  font-weight: var(--font-weight-semibold);
  cursor: pointer;
  transition: all 150ms ease;
}

.segmented-option.active {
  background-color: var(--bg-primary);
  color: var(--text-primary);
}

.segmented-option:active {
  opacity: 0.7;
}

/* ===== Badge ===== */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 2px 8px;
  background-color: var(--bg-secondary);
  border-radius: var(--radius-full);
  font-size: var(--font-size-caption);
  color: var(--text-secondary);
}

.badge.danger {
  background-color: var(--priority-high);
  color: white;
}

/* ===== Loading Indicator ===== */
.spinner {
  width: 20px;
  height: 20px;
  border: 2px solid var(--text-tertiary);
  border-top-color: var(--accent);
  border-radius: var(--radius-full);
  animation: spin 1s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

.loading-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-2xl);
  gap: var(--spacing-lg);
}

/* ===== Setup Screen ===== */
.setup-screen {
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-lg);
  background-color: var(--bg-primary);
}

.setup-icon {
  font-size: 64px;
  margin-bottom: var(--spacing-xl);
}

.setup-title {
  font-size: var(--font-size-title);
  font-weight: var(--font-weight-bold);
  color: var(--text-primary);
  text-align: center;
  margin-bottom: var(--spacing-sm);
}

.setup-subtitle {
  font-size: var(--font-size-body);
  color: var(--text-secondary);
  text-align: center;
  margin-bottom: var(--spacing-2xl);
  max-width: 300px;
}

.setup-form {
  width: 100%;
  max-width: 360px;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.setup-form-group {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.setup-form-label {
  font-size: var(--font-size-body-secondary);
  font-weight: var(--font-weight-semibold);
  color: var(--text-primary);
}

.setup-form-input {
  padding: var(--spacing-md) var(--spacing-lg);
  background-color: var(--bg-secondary);
  border: 1px solid var(--separator);
  border-radius: var(--radius-lg);
  font-size: var(--font-size-body);
  color: var(--text-primary);
  outline: none;
  transition: all 150ms ease;
}

.setup-form-input:focus {
  background-color: var(--bg-tertiary);
  border-color: var(--accent);
}

.setup-form-error {
  font-size: var(--font-size-caption);
  color: var(--priority-high);
  text-align: center;
  padding: var(--spacing-md);
  background-color: rgba(255, 59, 48, 0.1);
  border-radius: var(--radius-md);
}

/* ===== Mobile Navigation ===== */
.mobile-nav {
  display: none;
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--separator);
  padding: var(--spacing-sm) 0;
}

.mobile-nav-items {
  display: flex;
  list-style: none;
  width: 100%;
}

.mobile-nav-item {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-md);
  cursor: pointer;
  transition: background-color 150ms ease;
  border-top: 2px solid transparent;
  color: var(--text-secondary);
}

.mobile-nav-item:active {
  background-color: var(--bg-tertiary);
}

.mobile-nav-item.active {
  border-top-color: var(--accent);
  color: var(--accent);
}

.mobile-nav-icon {
  font-size: 20px;
}

.mobile-nav-label {
  font-size: 10px;
  font-weight: var(--font-weight-semibold);
}

/* ===== Responsive Design ===== */
@media (max-width: 767px) {
  .sidebar {
    display: none;
  }

  .view-container {
    padding-bottom: 60px;
  }

  .mobile-nav {
    display: flex;
  }

  .add-reminder-container {
    position: sticky;
    bottom: 60px;
  }

  .modal {
    max-height: 85vh;
  }

  .color-grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .icon-grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .view-content {
    padding: var(--spacing-md);
  }

  .reminder-item {
    padding: var(--spacing-sm);
  }
}

/* ===== Utilities ===== */
.hidden {
  display: none !important;
}

.text-center {
  text-align: center;
}

.opacity-disabled {
  opacity: 0.5;
  pointer-events: none;
}

.no-select {
  -webkit-user-select: none;
  user-select: none;
}

/* ===== iOS Safe Area Support ===== */
@supports (padding: max(0px)) {
  .sidebar {
    padding-right: max(0px, env(safe-area-inset-right));
    padding-left: max(0px, env(safe-area-inset-left));
  }

  .modal {
    padding-bottom: max(var(--spacing-lg), env(safe-area-inset-bottom));
  }

  .mobile-nav {
    padding-bottom: max(var(--spacing-sm), env(safe-area-inset-bottom));
  }

  .add-reminder-container {
    padding-bottom: max(var(--spacing-lg), env(safe-area-inset-bottom));
  }
}

/* ===== Print Styles ===== */
@media print {
  body {
    background-color: white;
  }

  .sidebar,
  .mobile-nav {
    display: none;
  }

  .main-content {
    width: 100%;
  }

  .reminder-item {
    page-break-inside: avoid;
  }
}