/* ========================================
   PWA Core Styling - 2025 Premium Edition
   ======================================== */

:root {
  /* Primary Colors - Vibrant Indigo */
  --primary: #6366f1;
  --primary-hover: #4f46e5;
  --primary-light: #818cf8;
  --primary-dark: #4338ca;

  /* Success/Completion Colors */
  --success: #10b981;
  --success-light: #34d399;
  --success-bg: #d1fae5;

  /* Warning/Streak Colors */
  --warning: #f59e0b;
  --warning-light: #fbbf24;
  --warning-bg: #fef3c7;

  /* Error Colors */
  --error: #ef4444;
  --error-light: #f87171;
  --error-bg: #fee2e2;

  /* Info Colors */
  --info: #3b82f6;
  --info-light: #60a5fa;
  --info-bg: #dbeafe;

  /* Neutral Colors - Light Mode */
  --bg: #f8fafc;
  --card-bg: #ffffff;
  --text: #1e293b;
  --text-secondary: #64748b;
  --text-muted: #94a3b8;
  --border: #e2e8f0;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
  --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -2px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

  /* Safe Areas for Notches/Home Bars */
  --safe-top: env(safe-area-inset-top);
  --safe-bottom: env(safe-area-inset-bottom);
  --safe-left: env(safe-area-inset-left);
  --safe-right: env(safe-area-inset-right);

  /* Navigation */
  --nav-height: 70px;

  /* Smooth Transitions */
  --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ========================================
   PWA Core Reset
   ======================================== */

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  /* Remove blue tap highlight on mobile */
  -webkit-tap-highlight-color: transparent;
  /* Prevent text selection on UI elements */
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
}

/* Allow text selection only in inputs */
input,
textarea,
[contenteditable="true"] {
  -webkit-user-select: text;
  -moz-user-select: text;
  -ms-user-select: text;
  user-select: text;
}

html {
  /* Prevents elastic scroll on iOS */
  overscroll-behavior-y: contain;
  /* Smooth scrolling */
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  background-color: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  /* Prevents bounce effect on scroll */
  overscroll-behavior-y: contain;
  /* Account for safe areas */
  padding-top: var(--safe-top);
  padding-bottom: var(--safe-bottom);
}

/* ========================================
   Utility Classes
   ======================================== */

.hidden {
  display: none !important;
}

/* Skeleton Loading */
.skeleton {
  background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  border-radius: 12px;
}

@keyframes shimmer {
  0% {
    background-position: -200% 0;
  }
  100% {
    background-position: 200% 0;
  }
}

.skeleton-text {
  height: 1rem;
  margin-bottom: 0.5rem;
}

.skeleton-card {
  height: 100px;
  margin-bottom: 1rem;
}

/* ========================================
   App Container
   ======================================== */

.app-container {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ========================================
   Authentication Screen
   ======================================== */

.auth-screen {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  background: linear-gradient(135deg, var(--primary-light) 0%, var(--primary) 100%);
}

.auth-card {
  background: var(--card-bg);
  border-radius: 24px;
  padding: 2.5rem;
  box-shadow: var(--shadow-lg);
  max-width: 420px;
  width: 100%;
  animation: slideUp 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.auth-header {
  text-align: center;
  margin-bottom: 2rem;
}

.auth-header h1 {
  font-size: 2rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.5rem;
}

.auth-header p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.auth-form h2 {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
  text-align: center;
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.875rem 1rem;
  border: 2px solid var(--border);
  border-radius: 12px;
  font-size: 1rem;
  font-family: inherit;
  transition: all var(--transition-base);
  background: var(--bg);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary);
  background: var(--card-bg);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-group textarea {
  resize: vertical;
  min-height: 80px;
}

.error-message {
  color: var(--error);
  font-size: 0.875rem;
  margin-top: 0.5rem;
  min-height: 20px;
}

.auth-switch {
  text-align: center;
  margin-top: 1.5rem;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.auth-switch a {
  color: var(--primary);
  text-decoration: none;
  font-weight: 600;
  transition: color var(--transition-fast);
}

.auth-switch a:hover {
  color: var(--primary-hover);
}

/* ========================================
   Buttons - Haptic Feedback Style
   ======================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.875rem 1.5rem;
  border: none;
  border-radius: 12px;
  font-size: 1rem;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: all var(--transition-base);
  width: 100%;
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.3);
  transform: translate(-50%, -50%);
  transition: width 0.6s, height 0.6s;
}

.btn:active::before {
  width: 300px;
  height: 300px;
}

.btn:active {
  transform: scale(0.97);
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none !important;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: white;
  box-shadow: var(--shadow);
}

.btn-primary:hover:not(:disabled) {
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.btn-success {
  background: linear-gradient(135deg, var(--success) 0%, #059669 100%);
  color: white;
  box-shadow: var(--shadow);
}

.btn-success:hover:not(:disabled) {
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.btn-secondary {
  background: var(--bg);
  color: var(--text);
  border: 2px solid var(--border);
}

.btn-secondary:hover:not(:disabled) {
  background: var(--card-bg);
  border-color: var(--text-secondary);
}

.btn-danger {
  background: linear-gradient(135deg, var(--error) 0%, #dc2626 100%);
  color: white;
  box-shadow: var(--shadow);
}

.btn-danger:hover:not(:disabled) {
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.btn-small {
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  width: auto;
}

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

.main-app {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--bg);
}

/* Nudge Banner */
.nudge-banner {
  background: linear-gradient(135deg, var(--success) 0%, var(--success-light) 100%);
  color: white;
  padding: 1rem 1.25rem;
  text-align: center;
  font-weight: 600;
  font-size: 0.95rem;
  box-shadow: var(--shadow);
  animation: slideDown 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  z-index: 100;
}

@keyframes slideDown {
  from {
    transform: translateY(-100%);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

/* Screen Container */
.screen-container {
  flex: 1;
  padding-bottom: calc(var(--nav-height) + var(--safe-bottom));
  overflow-y: auto;
  overflow-x: hidden;
}

.screen {
  animation: fadeIn 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

/* ========================================
   Screen Headers
   ======================================== */

.screen-header {
  background: var(--card-bg);
  padding: 1.5rem 1.25rem;
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(10px);
  background: rgba(255, 255, 255, 0.95);
}

.screen-title {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 0.25rem;
  color: var(--text);
}

.screen-subtitle,
.screen-date {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* ========================================
   Bento-Style Habit Cards
   ======================================== */

.checklist-container {
  padding: 1.25rem;
}

.habits-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.habit-item {
  background: var(--card-bg);
  border-radius: 20px;
  padding: 1.25rem;
  box-shadow: var(--shadow);
  display: flex;
  align-items: center;
  gap: 1rem;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.habit-item::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--primary);
  opacity: 0;
  transition: opacity var(--transition-base);
}

.habit-item:active {
  transform: scale(0.98);
  box-shadow: var(--shadow-sm);
}

.habit-item.completed {
  background: var(--success-bg);
}

.habit-item.completed::before {
  opacity: 1;
  background: var(--success);
}

.habit-item.completed .habit-name {
  color: var(--text-secondary);
  text-decoration: line-through;
  text-decoration-thickness: 2px;
}

.habit-check {
  min-width: 52px;
  height: 52px;
  border-radius: 50%;
  border: 3px solid var(--border);
  background: var(--card-bg);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-base);
  flex-shrink: 0;
}

.habit-check:active {
  transform: scale(0.9);
}

.habit-check .check-icon {
  opacity: 0;
  transform: scale(0);
  transition: all var(--transition-base);
  stroke-width: 3;
}

.habit-item.completed .habit-check {
  background: var(--success);
  border-color: var(--success);
  box-shadow: 0 0 0 4px var(--success-bg);
}

.habit-item.completed .habit-check .check-icon {
  opacity: 1;
  transform: scale(1);
  stroke: white;
}

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

.habit-name {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
  color: var(--text);
}

.habit-description {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

/* ========================================
   Library Screen
   ======================================== */

.section-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin: 1.5rem 1.25rem 1rem;
  color: var(--text);
}

.section-description {
  color: var(--text-secondary);
  font-size: 0.875rem;
  padding: 0 1.25rem;
  margin-bottom: 1rem;
}

.create-habit-section {
  padding: 1.25rem;
}

.create-habit-form {
  background: var(--card-bg);
  border-radius: 20px;
  padding: 1.5rem;
  margin: 0 0 1.25rem;
  box-shadow: var(--shadow);
  animation: slideUp 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.form-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  margin-top: 1rem;
}

.library-list {
  padding: 0 1.25rem 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.library-item {
  background: var(--card-bg);
  border-radius: 20px;
  padding: 1.25rem;
  box-shadow: var(--shadow);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  transition: all var(--transition-base);
}

.library-item:active {
  transform: scale(0.98);
}

.library-item-content {
  flex: 1;
  min-width: 0;
}

.library-item-name {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
  color: var(--text);
}

.library-item-description {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
  line-height: 1.4;
}

.library-item-meta {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.badge {
  display: inline-block;
  padding: 0.375rem 0.75rem;
  border-radius: 12px;
  font-size: 0.8rem;
  font-weight: 600;
  white-space: nowrap;
}

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

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

.badge-warning {
  background: var(--warning-bg);
  color: var(--warning);
}

/* ========================================
   Social Screen
   ======================================== */

.friend-search-section,
.leaderboard-section {
  padding: 1.25rem;
}

.search-box {
  display: flex;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.search-box input {
  flex: 1;
  padding: 0.875rem 1rem;
  border: 2px solid var(--border);
  border-radius: 12px;
  font-size: 1rem;
  font-family: inherit;
  background: var(--card-bg);
  transition: all var(--transition-base);
}

.search-box input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.search-results {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.search-result-item {
  background: var(--card-bg);
  border-radius: 16px;
  padding: 1rem;
  box-shadow: var(--shadow-sm);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  transition: all var(--transition-base);
}

.search-result-item:active {
  transform: scale(0.98);
}

.search-result-info h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
  color: var(--text);
}

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

.leaderboard-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.leaderboard-item {
  background: var(--card-bg);
  border-radius: 20px;
  padding: 1.25rem;
  box-shadow: var(--shadow);
  display: flex;
  align-items: center;
  gap: 1rem;
  transition: all var(--transition-base);
}

.leaderboard-item:active {
  transform: scale(0.98);
}

.leaderboard-item.is-me {
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.1) 0%, rgba(67, 56, 202, 0.1) 100%);
  border: 2px solid var(--primary);
  box-shadow: var(--shadow-md);
}

.leaderboard-rank {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-secondary);
  min-width: 50px;
  text-align: center;
  flex-shrink: 0;
}

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

.leaderboard-username {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.leaderboard-streak {
  color: var(--text-secondary);
  font-size: 0.875rem;
}

/* ========================================
   Profile/Stats Screen
   ======================================== */

.stats-section {
  padding: 1.25rem;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
}

.stat-card {
  background: var(--card-bg);
  border-radius: 20px;
  padding: 1.5rem;
  box-shadow: var(--shadow);
  text-align: center;
  transition: all var(--transition-base);
}

.stat-card:active {
  transform: scale(0.98);
}

.stat-card.highlight {
  background: linear-gradient(135deg, var(--warning-bg) 0%, #fed7aa 100%);
  border: 2px solid var(--warning);
  box-shadow: var(--shadow-md);
}

.stat-value {
  font-size: 2.25rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 0.5rem;
  line-height: 1;
}

.stat-card.highlight .stat-value {
  color: var(--warning);
}

.stat-label {
  font-size: 0.875rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.install-section,
.notifications-section,
.account-section {
  padding: 1.25rem;
}

.info-card {
  background: var(--card-bg);
  border-radius: 20px;
  padding: 1.5rem;
  box-shadow: var(--shadow);
}

.info-card p {
  margin-bottom: 1rem;
  line-height: 1.6;
}

.info-card p:last-child {
  margin-bottom: 0;
}

.text-warning {
  color: var(--warning);
}

.text-success {
  color: var(--success);
}

.install-steps ol {
  margin-left: 1.5rem;
  margin-top: 1rem;
}

.install-steps li {
  margin-bottom: 0.5rem;
  line-height: 1.5;
}

.settings-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.setting-item {
  background: var(--card-bg);
  border-radius: 16px;
  padding: 1.25rem;
  box-shadow: var(--shadow-sm);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  transition: all var(--transition-base);
}

.setting-item.disabled {
  opacity: 0.5;
}

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

.setting-info h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
  color: var(--text);
}

.setting-info p {
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

.setting-item input[type="time"] {
  padding: 0.5rem 0.75rem;
  border: 2px solid var(--border);
  border-radius: 8px;
  font-size: 0.9rem;
  font-family: inherit;
}

/* Toggle Switch */
.toggle {
  position: relative;
  display: inline-block;
  width: 52px;
  height: 28px;
  flex-shrink: 0;
}

.toggle input {
  opacity: 0;
  width: 0;
  height: 0;
}

.toggle-slider {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--border);
  transition: var(--transition-base);
  border-radius: 28px;
}

.toggle-slider:before {
  position: absolute;
  content: "";
  height: 22px;
  width: 22px;
  left: 3px;
  bottom: 3px;
  background-color: white;
  transition: var(--transition-base);
  border-radius: 50%;
  box-shadow: var(--shadow-sm);
}

.toggle input:checked + .toggle-slider {
  background: linear-gradient(135deg, var(--success) 0%, var(--success-light) 100%);
}

.toggle input:checked + .toggle-slider:before {
  transform: translateX(24px);
}

.toggle:active .toggle-slider:before {
  width: 26px;
}

/* ========================================
   Bottom Navigation - Glass Effect
   ======================================== */

.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: calc(var(--nav-height) + var(--safe-bottom));
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-around;
  align-items: center;
  padding: 0.5rem 0 calc(0.5rem + var(--safe-bottom));
  z-index: 1000;
  box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.05);
}

.nav-item {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.25rem;
  padding: 0.5rem;
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-base);
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.3px;
  position: relative;
}

.nav-item::before {
  content: '';
  position: absolute;
  top: -2px;
  left: 50%;
  transform: translateX(-50%);
  width: 0;
  height: 3px;
  background: var(--primary);
  border-radius: 0 0 3px 3px;
  transition: all var(--transition-base);
}

.nav-item.active {
  color: var(--primary);
}

.nav-item.active::before {
  width: 50%;
}

.nav-item:active {
  transform: scale(0.95);
}

.nav-item svg {
  stroke: currentColor;
  transition: all var(--transition-base);
}

.nav-item.active svg {
  stroke-width: 2.5;
}

/* ========================================
   Toast Notifications
   ======================================== */

.toast-container {
  position: fixed;
  bottom: calc(var(--nav-height) + var(--safe-bottom) + 1rem);
  left: 1rem;
  right: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  pointer-events: none;
  z-index: 2000;
}

.toast {
  background: var(--card-bg);
  color: var(--text);
  padding: 1rem 1.25rem;
  border-radius: 16px;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  transform: translateY(20px) scale(0.95);
  transition: all var(--transition-base);
  backdrop-filter: blur(10px);
  border: 1px solid var(--border);
  pointer-events: auto;
}

.toast.show {
  opacity: 1;
  transform: translateY(0) scale(1);
}

.toast-success {
  background: linear-gradient(135deg, var(--success) 0%, var(--success-light) 100%);
  color: white;
  border: none;
}

.toast-error {
  background: linear-gradient(135deg, var(--error) 0%, var(--error-light) 100%);
  color: white;
  border: none;
}

.toast-info {
  background: linear-gradient(135deg, var(--info) 0%, var(--info-light) 100%);
  color: white;
  border: none;
}

/* ========================================
   Loading & Empty States
   ======================================== */

.loading,
.empty-state {
  text-align: center;
  padding: 3rem 1.5rem;
  color: var(--text-secondary);
}

.empty-state p {
  margin-bottom: 0.5rem;
  line-height: 1.6;
}

/* ========================================
   Dark Mode
   ======================================== */

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f172a;
    --card-bg: #1e293b;
    --text: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --border: #334155;

    --success-bg: rgba(16, 185, 129, 0.15);
    --warning-bg: rgba(245, 158, 11, 0.15);
    --error-bg: rgba(239, 68, 68, 0.15);
    --info-bg: rgba(59, 130, 246, 0.15);
  }

  .habit-item.completed {
    background: rgba(16, 185, 129, 0.1);
  }

  .habit-check {
    background: var(--bg);
  }

  .screen-header {
    background: rgba(30, 41, 59, 0.95);
  }

  .bottom-nav {
    background: rgba(30, 41, 59, 0.9);
  }

  .leaderboard-item.is-me {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.15) 0%, rgba(67, 56, 202, 0.15) 100%);
  }

  .stat-card.highlight {
    background: linear-gradient(135deg, rgba(245, 158, 11, 0.2) 0%, rgba(251, 191, 36, 0.15) 100%);
  }

  .skeleton {
    background: linear-gradient(90deg, #334155 25%, #475569 50%, #334155 75%);
    background-size: 200% 100%;
  }
}

/* ========================================
   Responsive Design
   ======================================== */

@media (max-width: 768px) {
  .auth-card {
    padding: 2rem 1.5rem;
  }

  .screen-title {
    font-size: 1.5rem;
  }

  .stats-grid {
    grid-template-columns: 1fr;
  }
}

@media (min-width: 769px) {
  .app-container {
    max-width: 480px;
    margin: 0 auto;
    box-shadow: var(--shadow-lg);
  }

  .auth-screen {
    background: var(--bg);
  }

  .bottom-nav {
    max-width: 480px;
    left: 50%;
    transform: translateX(-50%);
  }
}

/* ========================================
   Safe Area Support
   ======================================== */

@supports (padding: max(0px)) {
  body {
    padding-left: max(0px, env(safe-area-inset-left));
    padding-right: max(0px, env(safe-area-inset-right));
  }
}

/* ========================================
   Print Styles (Hide for printing)
   ======================================== */

@media print {
  .bottom-nav,
  .nudge-banner,
  .toast-container {
    display: none;
  }
}