:root {
    --primary-color: #475569;
    /* Slate 600 */
    --primary-hover: #334155;
    /* Slate 700 */
    --background-color: #f8fafc;
    /* Slate 50 */
    --surface-color: #ffffff;
    --text-primary: #1e293b;
    /* Slate 800 */
    --text-secondary: #64748b;
    /* Slate 500 */
    --border-color: #e2e8f0;
    /* Slate 200 */
    --danger-color: #ef4444;
    /* Red 500 */
    --success-color: #22c55e;
    /* Green 500 */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --radius: 12px;
    --transition: all 0.2s ease;
    --input-bg: #ffffff;
}

body.dark-mode {
    --background-color: #0f172a;
    /* Slate 900 */
    --surface-color: #1e293b;
    /* Slate 800 */
    --text-primary: #f1f5f9;
    /* Slate 100 */
    --text-secondary: #94a3b8;
    /* Slate 400 */
    --border-color: #334155;
    /* Slate 700 */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.3);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.5), 0 2px 4px -2px rgb(0 0 0 / 0.3);
    --input-bg: #1e293b;
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--background-color);
    color: var(--text-primary);
    display: flex;
    justify-content: center;
    align-items: flex-start;
    min-height: 100vh;
    padding: 40px 20px;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.app-container {
    width: 100%;
    max-width: 900px;
    padding: 0 20px;
}

@media (min-width: 1200px) {
    .app-container {
        max-width: 1100px;
    }
}

@media (max-width: 768px) {
    .app-container {
        max-width: 100%;
        padding: 0 16px;
    }
}

header {
    margin-bottom: 32px;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
}

h1 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.date-display {
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 500;
}

.menu-container {
    display: flex;
    gap: 8px;
    position: relative;
}

.icon-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 8px;
    border-radius: 8px;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.icon-btn:hover {
    background-color: var(--border-color);
    color: var(--text-primary);
}

.menu-dropdown {
    position: absolute;
    top: 100%;
    right: 0;
    margin-top: 8px;
    background-color: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 8px;
    min-width: 180px;
    box-shadow: var(--shadow-md);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: var(--transition);
    z-index: 100;
}

.menu-dropdown.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.menu-item {
    display: flex;
    align-items: center;
    gap: 10px;
    width: 100%;
    padding: 10px 12px;
    border: none;
    background: transparent;
    color: var(--text-primary);
    font-size: 0.9rem;
    text-align: left;
    cursor: pointer;
    border-radius: 6px;
    transition: var(--transition);
    white-space: nowrap;
    /* Prevent wrapping */
}

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

.menu-item.danger {
    color: var(--danger-color);
}

.menu-item.danger:hover {
    background-color: #fee2e2;
}

.input-group {
    display: flex;
    gap: 12px;
    margin-bottom: 32px;
}

#todo-input {
    flex: 1;
    padding: 12px 16px;
    font-size: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    background-color: var(--surface-color);
    color: var(--text-primary);
    outline: none;
    transition: var(--transition);
}

#todo-input:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(71, 85, 105, 0.1);
}

#todo-input::placeholder {
    color: var(--text-secondary);
}

#add-btn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    width: 48px;
    height: 48px;
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

#add-btn:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
}

#add-btn:active {
    transform: translateY(0);
}

.todo-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.todo-item {
    background-color: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 0;
    transition: var(--transition);
}

.todo-item:hover:not(.dragging) {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.todo-item[draggable="true"] {
    cursor: move;
}

.todo-item.dragging {
    opacity: 0.5;
    transform: rotate(2deg) !important;
    transition: none !important;
}

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

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

/* Disable hover effects on all items when dragging */
body.is-dragging .todo-item:hover {
    transform: none !important;
    box-shadow: var(--shadow-sm) !important;
}

body.is-dragging .subtask-item:hover {
    background-color: rgba(71, 85, 105, 0.05) !important;
}

.add-subtask-btn {
    background: transparent;
    border: none;
    color: var(--primary-color);
    cursor: pointer;
    padding: 4px 8px;
    border-radius: 6px;
    font-size: 1.2rem;
    font-weight: bold;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 32px;
    height: 32px;
    opacity: 0.7;
}

.todo-item:hover .add-subtask-btn,
.add-subtask-btn:hover {
    opacity: 1;
}

.add-subtask-btn:hover {
    background-color: rgba(71, 85, 105, 0.1);
}

.todo-main-content {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    width: 100%;
    padding-top: 2px;
}

.subtasks-container {
    margin-top: 12px;
    padding-left: 44px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.subtask-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 8px 12px;
    background-color: rgba(71, 85, 105, 0.05);
    border-radius: 8px;
    font-size: 0.85rem;
    transition: var(--transition);
}

.subtask-text {
    flex: 1;
    color: var(--text-primary);
    line-height: 1.5;
    cursor: pointer;
    white-space: pre-wrap;
    word-wrap: break-word;
    padding-top: 5px;
    /* Match input border+padding (1px+4px) */
}

.subtask-checkbox {
    width: 20px;
    /* Increased from 18px to match line-height better */
    height: 20px;
    cursor: pointer;
    margin: 0;
    padding: 0;
    flex-shrink: 0;
    align-self: center;
    position: relative;
    top: 0;
    accent-color: var(--primary-color);
}

.subtask-item .checkbox-wrapper {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 20px;
    height: 20px;
    margin: 0;
    padding: 0;
    padding-top: 0;
    margin-top: 5px;
    /* Align with text padding-top: 5px */
}

.subtask-delete-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 4px;
    border-radius: 6px;
    opacity: 0;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.subtask-item:hover .subtask-delete-btn {
    opacity: 1;
}

.subtask-delete-btn:hover {
    color: var(--danger-color);
    background-color: rgba(239, 68, 68, 0.1);
}

.subtask-input-container {
    display: flex;
    gap: 8px;
    margin-top: 8px;
    padding-left: 0;
    animation: slideDown 0.2s ease-out;
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.subtask-input-wrapper {
    display: flex;
    gap: 8px;
    width: 100%;
    align-items: center;
}

.subtask-input {
    flex: 1;
    padding: 8px 12px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 0.9rem;
    outline: none;
    background-color: var(--surface-color);
    color: var(--text-primary);
    transition: var(--transition);
}

.subtask-input:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(71, 85, 105, 0.1);
}

.subtask-add-btn,
.subtask-cancel-btn {
    padding: 8px 16px;
    border-radius: 8px;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    white-space: nowrap;
}

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

.subtask-add-btn:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
}

.subtask-cancel-btn {
    background-color: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
}

.subtask-cancel-btn:hover {
    background-color: var(--background-color);
    color: var(--text-primary);
}

.checkbox-wrapper {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 24px;
    height: 24px;
    flex-shrink: 0;
    margin-top: 4px;
    /* Align with text and buttons */
}

.checkbox {
    appearance: none;
    width: 24px;
    height: 24px;
    border: 2px solid var(--border-color);
    border-radius: 6px;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
    z-index: 1;
    margin: 0;
    padding: 0;
    flex-shrink: 0;
}

.checkbox:checked {
    background-color: var(--success-color);
    border-color: var(--success-color);
}

.checkbox:checked::after {
    content: '';
    position: absolute;
    left: 7px;
    top: 3px;
    width: 5px;
    height: 10px;
    border: solid white;
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
}

.delete-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 8px;
    border-radius: 8px;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0.6;
}

.todo-item:hover .delete-btn,
.delete-btn:hover {
    opacity: 1;
    color: #ef4444;
    background-color: rgba(239, 68, 68, 0.1);
}

.empty-state {
    display: none;
    text-align: center;
    padding: 48px 20px;
    color: var(--text-secondary);
    background: transparent;
    border-radius: 16px;
    border: none;
}

.empty-state.visible {
    display: block;
}

.empty-icon {
    margin-bottom: 16px;
    opacity: 0.5;
    filter: drop-shadow(0 4px 6px rgba(0, 0, 0, 0.1));
}

.todo-main-content {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    width: 100%;
    padding-top: 0;
}

.todo-content {
    flex: 1;
    display: flex;
    align-items: flex-start;
    min-width: 0;
}

.todo-text {
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-primary);
    cursor: pointer;
    transition: var(--transition);
    line-height: 1.5;
    white-space: pre-wrap;
    word-wrap: break-word;
    padding-top: 4px;
    /* Push text down to align with buttons */
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
}

.todo-actions {
    display: flex;
    align-items: center;
    /* Center items vertically */
    gap: 12px;
    flex-shrink: 0;
    padding-top: 0;
    height: 32px;
    /* Fixed height to match buttons */
}

.todo-timestamp {
    font-size: 0.85rem;
    color: var(--text-secondary);
    white-space: nowrap;
    padding-top: 0;
    font-weight: 500;
}

.subtask-edit-input {
    flex: 1;
    width: 100%;
    /* Force full width */
    box-sizing: border-box;
    font-size: 0.85rem;
    padding: 4px 8px;
    border: 1px solid var(--primary-color);
    border-radius: 6px;
    background-color: var(--input-bg);
    color: var(--text-primary);
    outline: none;
    resize: none;
    overflow: hidden;
    font-family: inherit;
    line-height: 1.5;
    min-height: 28px;
    backdrop-filter: blur(4px);
}

.todo-edit-input {
    flex: 1;
    font-size: 1rem;
    font-weight: 500;
    padding: 8px 12px;
    border: 1px solid rgba(71, 85, 105, 0.3);
    border-radius: 8px;
    background-color: var(--input-bg);
    color: var(--text-primary);
    outline: none;
    resize: none;
    overflow: hidden;
    font-family: inherit;
    line-height: 1.5;
    min-height: 32px;
    backdrop-filter: blur(4px);
}

.todo-edit-input:focus {
    box-shadow: 0 0 0 3px rgba(71, 85, 105, 0.2);
    background-color: rgba(255, 255, 255, 0.6);
}

.hidden {
    display: none !important;
}

/* Auth/Modal Styles */
.login-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: var(--background-color);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

.login-card {
    background-color: var(--surface-color);
    padding: 40px;
    border-radius: 16px;
    box-shadow: var(--shadow-md);
    width: 100%;
    max-width: 400px;
    text-align: center;
    border: 1px solid var(--border-color);
}

.login-card h2 {
    margin-bottom: 8px;
    color: var(--text-primary);
    font-size: 2rem;
    font-weight: 700;
}

.login-card p {
    color: var(--text-secondary);
    margin-bottom: 32px;
}

#login-form,
#password-form {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.login-card input {
    padding: 12px 16px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background-color: var(--surface-color);
    color: var(--text-primary);
    font-size: 1rem;
    outline: none;
    transition: var(--transition);
}

.login-card input:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(71, 85, 105, 0.1);
}

.primary-btn {
    padding: 12px;
    border-radius: 8px;
    border: none;
    background-color: var(--primary-color);
    color: white;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.primary-btn:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
}

.text-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-weight: 600;
    cursor: pointer;
    padding: 8px;
    margin-top: 8px;
    font-size: 0.9rem;
}

.text-btn:hover {
    color: var(--text-primary);
    text-decoration: underline;
}

/* Modal Styles */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 2000;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
}

.modal.show {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background-color: var(--surface-color);
    padding: 32px;
    border-radius: 16px;
    width: 90%;
    max-width: 400px;
    box-shadow: var(--shadow-md);
    transform: scale(0.9);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.modal.show .modal-content {
    transform: scale(1);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}

.modal-header h3 {
    font-size: 1.5rem;
    color: var(--text-primary);
    font-weight: 700;
}

.close-modal {
    background: transparent;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-secondary);
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    border-radius: 50%;
}

.close-modal:hover {
    color: var(--danger-color);
    background-color: rgba(239, 68, 68, 0.1);
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-secondary);
    font-weight: 500;
}

.form-group input {
    width: 100%;
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    outline: none;
    transition: var(--transition);
    background-color: var(--background-color);
    color: var(--text-primary);
}

.form-group input:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(71, 85, 105, 0.1);
}

.modal-footer {
    display: flex;
    justify-content: flex-end;
    gap: 12px;
    margin-top: 32px;
}

.btn-secondary {
    padding: 8px 16px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background-color: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
}

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

.btn-primary {
    padding: 8px 16px;
    border-radius: 8px;
    border: none;
    background-color: var(--primary-color);
    color: white;
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
}