* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
    'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue',
    sans-serif;
  background: linear-gradient(135deg, #f5f5f5 0%, #e8e8e8 100%);
  min-height: 100vh;
  line-height: 1.6;
}

.app {
  max-width: 600px;
  margin: 0 auto;
  padding: 20px;
}

.app-header {
  text-align: center;
  margin-bottom: 30px;
}

.app-header h1 {
  color: #333;
  font-size: 2.5rem;
  font-weight: 600;
  letter-spacing: -0.5px;
}

.app-main {
  background: white;
  border-radius: 12px;
  padding: 24px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

/* TodoForm */
.todo-form {
  display: flex;
  gap: 12px;
  margin-bottom: 24px;
}

.todo-input {
  flex: 1;
  padding: 12px 16px;
  border: 2px solid #e0e0e0;
  border-radius: 8px;
  font-size: 16px;
  transition: all 0.2s ease;
  font-family: inherit;
}

.todo-input:focus {
  outline: none;
  border-color: #4CAF50;
  box-shadow: 0 0 0 3px rgba(76, 175, 80, 0.1);
}

.todo-input:disabled {
  background-color: #f5f5f5;
  color: #999;
  cursor: not-allowed;
}

.add-button {
  padding: 12px 24px;
  background-color: #4CAF50;
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
  white-space: nowrap;
}

.add-button:hover:not(:disabled) {
  background-color: #45a049;
  transform: translateY(-1px);
  box-shadow: 0 4px 8px rgba(76, 175, 80, 0.3);
}

.add-button:active:not(:disabled) {
  transform: translateY(0);
}

.add-button:disabled {
  background-color: #ccc;
  cursor: not-allowed;
  opacity: 0.6;
}

/* TodoList */
.todo-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

/* TodoItem */
.todo-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px;
  background: #f9f9f9;
  border: 1px solid #e8e8e8;
  border-radius: 8px;
  transition: all 0.2s ease;
}

.todo-item:hover {
  background: #f0f0f0;
  border-color: #d0d0d0;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.05);
}

.todo-content {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: 1;
  min-width: 0;
}

.todo-checkbox {
  width: 20px;
  height: 20px;
  cursor: pointer;
  accent-color: #4CAF50;
  flex-shrink: 0;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.todo-checkbox:hover {
  transform: scale(1.15);
}

.todo-checkbox:focus {
  outline: 2px solid #4CAF50;
  outline-offset: 2px;
}

.todo-title {
  font-size: 16px;
  color: #333;
  word-break: break-word;
  transition: all 0.2s ease;
}

.todo-title.completed {
  text-decoration: line-through;
  color: #999;
}

.delete-button {
  padding: 8px 16px;
  background-color: #f44336;
  color: white;
  border: none;
  border-radius: 6px;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.2s ease;
  white-space: nowrap;
  flex-shrink: 0;
  margin-left: 8px;
  font-weight: 500;
}

.delete-button:hover {
  background-color: #da190b;
  transform: translateY(-1px);
  box-shadow: 0 4px 8px rgba(244, 67, 54, 0.3);
}

.delete-button:active {
  transform: translateY(0);
}

.delete-button:focus {
  outline: 2px solid #f44336;
  outline-offset: 2px;
}

/* EmptyState */
.empty-state {
  text-align: center;
  padding: 48px 24px;
  color: #999;
}

.empty-message {
  font-size: 20px;
  font-weight: 500;
  color: #666;
  margin-bottom: 8px;
}

.empty-hint {
  font-size: 14px;
  color: #999;
}

/* Loading State */
.loading {
  text-align: center;
  padding: 40px 20px;
  color: #666;
  font-size: 16px;
}

/* Error Message */
.error-message {
  padding: 12px 16px;
  background-color: #ffebee;
  color: #c62828;
  border: 1px solid #ef5350;
  border-radius: 8px;
  margin-bottom: 16px;
  font-size: 14px;
  text-align: center;
}

/* ConfirmDialog */
.dialog-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  animation: fadeIn 0.2s ease;
}

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

.dialog-content {
  background: white;
  padding: 24px;
  border-radius: 12px;
  max-width: 400px;
  width: 90%;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
  animation: slideUp 0.2s ease;
}

@keyframes slideUp {
  from {
    transform: translateY(10px);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

.dialog-message {
  margin-bottom: 20px;
  font-size: 16px;
  color: #333;
  line-height: 1.5;
}

.dialog-buttons {
  display: flex;
  gap: 12px;
  justify-content: flex-end;
}

.cancel-button {
  padding: 10px 20px;
  background-color: #f0f0f0;
  color: #333;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  font-size: 14px;
  font-weight: 500;
  transition: all 0.2s ease;
}

.cancel-button:hover {
  background-color: #e0e0e0;
  transform: translateY(-1px);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.cancel-button:focus {
  outline: 2px solid #333;
  outline-offset: 2px;
}

.confirm-button {
  padding: 10px 20px;
  background-color: #f44336;
  color: white;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  font-size: 14px;
  font-weight: 500;
  transition: all 0.2s ease;
}

.confirm-button:hover {
  background-color: #da190b;
  transform: translateY(-1px);
  box-shadow: 0 4px 8px rgba(244, 67, 54, 0.3);
}

.confirm-button:active {
  transform: translateY(0);
}

.confirm-button:focus {
  outline: 2px solid #f44336;
  outline-offset: 2px;
}

/* Responsive Design */
@media (max-width: 640px) {
  .app {
    padding: 12px;
  }

  .app-header h1 {
    font-size: 2rem;
  }

  .app-main {
    padding: 16px;
  }

  .todo-form {
    flex-direction: column;
    gap: 10px;
  }

  .add-button {
    width: 100%;
  }

  .todo-item {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }

  .todo-content {
    width: 100%;
  }

  .delete-button {
    width: 100%;
    margin-left: 0;
  }

  .dialog-content {
    width: 95%;
  }
}