/* Styling & Variables */
:root {
  --bg-color: #0d0f17;
  --panel-bg: rgba(22, 26, 43, 0.65);
  --panel-border: rgba(255, 255, 255, 0.08);
  --text-primary: #f1f3f9;
  --text-secondary: #94a3b8;
  --accent-primary: #8b5cf6;
  --accent-secondary: #3b82f6;
  --accent-gradient: linear-gradient(135deg, #8b5cf6 0%, #3b82f6 100%);
  --success-color: #10b981;
  --error-color: #ef4444;
  --border-radius: 16px;
  --shadow-lg: 0 10px 30px -10px rgba(0, 0, 0, 0.5);
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);

  /* Theme tokens */
  --stat-card-bg: rgba(255, 255, 255, 0.03);
  --stat-card-hover-bg: rgba(255, 255, 255, 0.05);
  --stat-card-hover-border: rgba(255, 255, 255, 0.15);
  --stat-val-color: #ffffff;
  --warning-color: #f59e0b;
  --input-bg: rgba(255, 255, 255, 0.04);
  --filter-btn-hover-color: #ffffff;
  --filter-btn-hover-bg: rgba(255, 255, 255, 0.05);
  --filter-btn-active-color: #ffffff;
  --filter-btn-active-bg: rgba(139, 92, 246, 0.15);
  --filter-btn-active-border: rgba(139, 92, 246, 0.25);
  --todo-item-bg: rgba(255, 255, 255, 0.02);
  --todo-item-hover-bg: rgba(255, 255, 255, 0.04);
  --todo-item-hover-border: rgba(255, 255, 255, 0.15);
  --badge-bg: rgba(139, 92, 246, 0.15);
  --badge-color: #c084fc;
  --badge-border: rgba(139, 92, 246, 0.25);
  --toast-bg: rgba(22, 26, 43, 0.9);
  --toast-color: #ffffff;
  --theme-btn-hover-bg: rgba(255, 255, 255, 0.08);
}

:root[data-theme="light"] {
  --bg-color: #f8fafc;
  --panel-bg: rgba(255, 255, 255, 0.75);
  --panel-border: rgba(15, 23, 42, 0.06);
  --text-primary: #0f172a;
  --text-secondary: #64748b;
  --accent-primary: #7c3aed;
  --accent-secondary: #2563eb;
  --accent-gradient: linear-gradient(135deg, #7c3aed 0%, #2563eb 100%);
  --success-color: #059669;
  --error-color: #dc2626;
  --shadow-lg: 0 10px 30px -10px rgba(15, 23, 42, 0.15);

  /* Light theme overrides */
  --stat-card-bg: rgba(0, 0, 0, 0.02);
  --stat-card-hover-bg: rgba(0, 0, 0, 0.04);
  --stat-card-hover-border: rgba(0, 0, 0, 0.08);
  --stat-val-color: #0f172a;
  --warning-color: #d97706;
  --input-bg: rgba(0, 0, 0, 0.02);
  --filter-btn-hover-color: #0f172a;
  --filter-btn-hover-bg: rgba(0, 0, 0, 0.04);
  --filter-btn-active-color: #7c3aed;
  --filter-btn-active-bg: rgba(124, 58, 237, 0.08);
  --filter-btn-active-border: rgba(124, 58, 237, 0.15);
  --todo-item-bg: rgba(0, 0, 0, 0.01);
  --todo-item-hover-bg: rgba(0, 0, 0, 0.03);
  --todo-item-hover-border: rgba(0, 0, 0, 0.06);
  --badge-bg: rgba(124, 58, 237, 0.08);
  --badge-color: #7c3aed;
  --badge-border: rgba(124, 58, 237, 0.15);
  --toast-bg: rgba(255, 255, 255, 0.95);
  --toast-color: #0f172a;
  --theme-btn-hover-bg: rgba(0, 0, 0, 0.05);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: 'Outfit', sans-serif;
  -webkit-font-smoothing: antialiased;
}

body {
  background-color: var(--bg-color);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  overflow-x: hidden;
  position: relative;
  padding: 20px;
  transition: background-color 0.4s ease, color 0.4s ease;
}

/* Background blob decorations */
.background-decor {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  overflow: hidden;
}

.blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(100px);
  opacity: 0.15;
}

.blob-1 {
  top: -10%;
  right: 10%;
  width: 400px;
  height: 400px;
  background: var(--accent-primary);
}

.blob-2 {
  bottom: -10%;
  left: 10%;
  width: 500px;
  height: 500px;
  background: var(--accent-secondary);
}

/* Container */
.app-container {
  width: 100%;
  max-width: 540px;
  background: var(--panel-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--panel-border);
  border-radius: 24px;
  padding: 40px;
  box-shadow: var(--shadow-lg);
  display: flex;
  flex-direction: column;
  gap: 28px;
  transition: background 0.4s ease, border 0.4s ease, box-shadow 0.4s ease;
}

/* Header */
.app-header {
  display: flex;
  flex-direction: column;
  gap: 8px;
  position: relative;
}

/* Header Actions Container */
.header-actions {
  position: absolute;
  top: 4px;
  right: 0;
  display: flex;
  align-items: center;
  gap: 12px;
}

/* Google Sync Button */
.google-sync-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  border-radius: 20px;
  border: 1px solid var(--panel-border);
  background: var(--stat-card-bg);
  color: var(--text-primary);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.google-sync-btn i {
  color: #4285F4;
}

.google-sync-btn:hover {
  background: var(--theme-btn-hover-bg);
  border-color: var(--stat-card-hover-border);
  transform: translateY(-2px);
}

.google-sync-btn:active {
  transform: translateY(0);
}

/* Theme Toggle Button */
.theme-toggle-btn {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--panel-border);
  background: var(--stat-card-bg);
  color: var(--text-primary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  transition: var(--transition);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.theme-toggle-btn:hover {
  background: var(--theme-btn-hover-bg);
  border-color: var(--stat-card-hover-border);
  transform: scale(1.08) rotate(15deg);
}

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

.header-main {
  display: flex;
  align-items: center;
  gap: 12px;
}

.header-main h1 {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.5px;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.badge {
  background: var(--badge-bg);
  color: var(--badge-color);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 8px;
  border-radius: 8px;
  border: 1px solid var(--badge-border);
}

.subtitle {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 8px;
}

/* Stats */
.stats-container {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-top: 10px;
}

.stat-card {
  background: var(--stat-card-bg);
  border: 1px solid var(--panel-border);
  border-radius: var(--border-radius);
  padding: 12px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  transition: var(--transition);
}

.stat-card:hover {
  background: var(--stat-card-hover-bg);
  border-color: var(--stat-card-hover-border);
}

.stat-val {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--stat-val-color);
}

#completed-count {
  color: var(--success-color);
}

#pending-count {
  color: var(--warning-color);
}

.stat-lbl {
  font-size: 0.75rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  font-weight: 500;
}

/* Input Form */
.todo-input-group {
  display: flex;
  gap: 10px;
}

.todo-input-group input {
  flex: 1;
  background: var(--input-bg);
  border: 1px solid var(--panel-border);
  padding: 14px 18px;
  border-radius: var(--border-radius);
  color: var(--text-primary);
  font-size: 1rem;
  transition: var(--transition);
}

.todo-input-group input:focus {
  outline: none;
  background: var(--stat-card-hover-bg);
  border-color: var(--accent-primary);
  box-shadow: 0 0 15px rgba(139, 92, 246, 0.2);
}

.todo-input-group button {
  background: var(--accent-gradient);
  border: none;
  color: #fff;
  font-weight: 600;
  padding: 0 24px;
  border-radius: var(--border-radius);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 1rem;
  box-shadow: 0 4px 15px rgba(139, 92, 246, 0.3);
  transition: var(--transition);
}

.todo-input-group button:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(139, 92, 246, 0.45);
  opacity: 0.95;
}

.todo-input-group button:active {
  transform: translateY(0);
}

/* Filters */
.filter-bar {
  display: flex;
  gap: 8px;
  border-bottom: 1px solid var(--panel-border);
  padding-bottom: 16px;
}

.filter-btn {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  font-weight: 600;
  font-size: 0.9rem;
  padding: 8px 16px;
  border-radius: 20px;
  cursor: pointer;
  transition: var(--transition);
}

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

.filter-btn.active {
  color: var(--filter-btn-active-color);
  background: var(--filter-btn-active-bg);
  border: 1px solid var(--filter-btn-active-border);
}

/* List Wrapper */
.list-wrapper {
  position: relative;
  min-height: 150px;
}

.todo-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.todo-item {
  background: var(--todo-item-bg);
  border: 1px solid var(--panel-border);
  padding: 16px 20px;
  border-radius: var(--border-radius);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  transition: var(--transition);
  animation: slideIn 0.3s ease forwards;
}

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

.todo-item-left {
  display: flex;
  align-items: center;
  gap: 14px;
  flex: 1;
}

/* Checkbox Style */
.checkbox-container {
  display: block;
  position: relative;
  width: 22px;
  height: 22px;
  cursor: pointer;
  user-select: none;
}

.checkbox-container input {
  position: absolute;
  opacity: 0;
  cursor: pointer;
  height: 0;
  width: 0;
}

.checkmark {
  position: absolute;
  top: 0;
  left: 0;
  height: 22px;
  width: 22px;
  background-color: transparent;
  border: 2px solid var(--text-secondary);
  border-radius: 6px;
  transition: var(--transition);
}

.checkbox-container:hover input ~ .checkmark {
  border-color: var(--accent-primary);
}

.checkbox-container input:checked ~ .checkmark {
  background: var(--accent-gradient);
  border-color: transparent;
}

.checkmark:after {
  content: "";
  position: absolute;
  display: none;
  left: 7px;
  top: 3px;
  width: 5px;
  height: 10px;
  border: solid white;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

.checkbox-container input:checked ~ .checkmark:after {
  display: block;
}

/* Text styles */
.todo-text {
  font-size: 1rem;
  color: var(--text-primary);
  transition: var(--transition);
  line-height: 1.4;
  word-break: break-word;
}

.todo-item.completed .todo-text {
  color: var(--text-secondary);
  text-decoration: line-through;
  opacity: 0.65;
}

/* Delete Button */
.delete-btn {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  font-size: 1rem;
  cursor: pointer;
  padding: 8px;
  border-radius: 8px;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
}

.delete-btn:hover {
  color: var(--error-color);
  background: rgba(239, 68, 68, 0.1);
  transform: scale(1.1);
}

/* Empty State */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
  padding: 40px 20px;
  text-align: center;
  color: var(--text-secondary);
  transition: var(--transition);
}

.empty-icon {
  font-size: 3rem;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  opacity: 0.7;
}

.empty-state.hidden {
  display: none;
}

/* Toasts */
.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  z-index: 1000;
}

.toast {
  background: var(--toast-bg);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--panel-border);
  padding: 14px 20px;
  border-radius: var(--border-radius);
  color: var(--toast-color);
  display: flex;
  align-items: center;
  gap: 12px;
  box-shadow: var(--shadow-lg);
  font-size: 0.9rem;
  min-width: 220px;
  animation: slideInToast 0.3s cubic-bezier(0.34, 1.56, 0.64, 1) forwards;
}

.toast-success {
  border-left: 4px solid var(--success-color);
}

.toast-error {
  border-left: 4px solid var(--error-color);
}

/* Keyframes */
@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideInToast {
  from {
    opacity: 0;
    transform: translateX(100px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* Responsiveness */
@media (max-width: 480px) {
  .app-container {
    padding: 24px;
  }
  
  .todo-input-group {
    flex-direction: column;
  }
  
  .todo-input-group button {
    padding: 14px;
    justify-content: center;
  }
  
  .stats-container {
    grid-template-columns: 1fr;
    gap: 8px;
  }
}

/* User Profile Header Element */
.user-profile {
  display: flex;
  align-items: center;
  gap: 10px;
  background: var(--stat-card-bg);
  border: 1px solid var(--panel-border);
  padding: 6px 14px;
  border-radius: 24px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.user-avatar {
  width: 26px;
  height: 26px;
  border-radius: 50%;
  object-fit: cover;
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.user-name {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-primary);
}

.logout-btn {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
  padding: 4px;
  border-radius: 50%;
  transition: var(--transition);
}

.logout-btn:hover {
  color: var(--error-color);
  background: rgba(239, 68, 68, 0.1);
  transform: scale(1.05);
}

.hidden {
  display: none !important;
}

/* Modal Styles */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(13, 15, 23, 0.8);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  z-index: 100;
  display: flex;
  justify-content: center;
  align-items: center;
  opacity: 1;
  transition: var(--transition);
}

:root[data-theme="light"] .modal-overlay {
  background: rgba(248, 250, 252, 0.8);
}

.modal-overlay.hidden {
  opacity: 0;
  pointer-events: none;
  display: none !important;
}

.modal-content {
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  border-radius: 24px;
  width: 90%;
  max-width: 420px;
  padding: 36px 30px;
  box-shadow: var(--shadow-lg);
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  animation: modalScaleIn 0.4s cubic-bezier(0.34, 1.56, 0.64, 1) forwards;
}

@keyframes modalScaleIn {
  from {
    opacity: 0;
    transform: scale(0.9) translateY(20px);
  }
  to {
    opacity: 1;
    transform: scale(1) translateY(0);
  }
}

.close-modal-btn {
  position: absolute;
  top: 20px;
  right: 20px;
  background: transparent;
  border: none;
  color: var(--text-secondary);
  font-size: 1.2rem;
  cursor: pointer;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
}

.close-modal-btn:hover {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-primary);
}

:root[data-theme="light"] .close-modal-btn:hover {
  background: rgba(0, 0, 0, 0.05);
}

.modal-icon {
  width: 64px;
  height: 64px;
  background: var(--accent-gradient);
  color: #ffffff;
  font-size: 1.8rem;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  box-shadow: 0 8px 24px rgba(139, 92, 246, 0.3);
}

.modal-content h2 {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 10px;
  color: var(--text-primary);
}

.modal-content p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 30px;
  max-width: 300px;
}

.google-signup-btn {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 14px 24px;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--panel-border);
  border-radius: 14px;
  color: var(--text-primary);
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
}

:root[data-theme="light"] .google-signup-btn {
  background: #ffffff;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.google-signup-btn:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

:root[data-theme="light"] .google-signup-btn:hover {
  background: #f8fafc;
  border-color: rgba(0, 0, 0, 0.1);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

.google-signup-btn i {
  color: #ea4335;
  font-size: 1.1rem;
}