/* CSS Variables for Dark Mode (Default) */
:root {
    --bg-body: #1a1a1a;
    --bg-container: #242424;
    --bg-elevated: #2d2d2d;
    --bg-section: #2a2a2a;
    --bg-hover: #333333;
    --bg-focus: #1e3a5f;

    --text-primary: #e0e0e0;
    --text-secondary: #b0b0b0;
    --text-tertiary: #808080;
    --text-heading: #f0f0f0;

    --border-primary: #3a3a3a;
    --border-secondary: #444444;
    --border-focus: #3498db;

    --primary: #4a9eff;
    --primary-hover: #3d8ae0;
    --secondary: #6b7280;
    --secondary-hover: #9ca3af;
    --danger: #ef4444;
    --danger-hover: #dc2626;

    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 16px rgba(0, 0, 0, 0.5);
}

/* Light Mode Theme */
[data-theme="light"] {
    --bg-body: #f5f5f5;
    --bg-container: #ffffff;
    --bg-elevated: #ffffff;
    --bg-section: #f8f9fa;
    --bg-hover: #f0f0f0;
    --bg-focus: #e8f4fd;

    --text-primary: #333333;
    --text-secondary: #666666;
    --text-tertiary: #999999;
    --text-heading: #2c3e50;

    --border-primary: #e0e0e0;
    --border-secondary: #ddd;
    --border-focus: #3498db;

    --primary: #3498db;
    --primary-hover: #2980b9;
    --secondary: #95a5a6;
    --secondary-hover: #7f8c8d;
    --danger: #e74c3c;
    --danger-hover: #c0392b;

    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 8px 16px rgba(0, 0, 0, 0.2);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-body);
    padding: 20px;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Accessibility Utilities */
.skip-link {
    position: absolute;
    top: -42px;
    left: 0;
    background: var(--primary);
    color: #ffffff;
    padding: 8px 16px;
    text-decoration: none;
    z-index: 10000;
    font-weight: bold;
}

.skip-link:focus {
    top: 0;
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    margin: -1px;
    padding: 0;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Focus Indicators */
*:focus {
    outline: 2px solid var(--border-focus);
    outline-offset: 2px;
}

*:focus:not(:focus-visible) {
    outline: none;
}

*:focus-visible {
    outline: 2px solid var(--border-focus);
    outline-offset: 2px;
}

button:focus-visible,
a:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
    outline: 2px solid var(--border-focus);
    outline-offset: 2px;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    background: var(--bg-container);
    padding: 30px;
    border-radius: 8px;
    box-shadow: var(--shadow-sm);
    transition: background-color 0.3s ease;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 2px solid var(--border-primary);
}

h1 {
    font-size: 28px;
    color: var(--text-heading);
}

.header-buttons {
    display: flex;
    gap: 10px;
    align-items: center;
}

.settings-dropdown {
    position: relative;
}

.settings-menu {
    display: none;
    position: absolute;
    top: 100%;
    right: 0;
    margin-top: 5px;
    background-color: var(--bg-elevated);
    border: 1px solid var(--border-primary);
    border-radius: 4px;
    box-shadow: var(--shadow-md);
    min-width: 180px;
    z-index: 1000;
}

.settings-menu.show {
    display: block;
}

.settings-menu-item {
    width: 100%;
    padding: 12px 16px;
    border: none;
    background: none;
    text-align: left;
    cursor: pointer;
    font-size: 14px;
    color: var(--text-primary);
    transition: background-color 0.2s;
    display: block;
}

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

.settings-menu-item:first-child {
    border-radius: 4px 4px 0 0;
}

.settings-menu-item:last-child {
    border-radius: 0 0 4px 4px;
}

.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: background-color 0.2s;
}

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

.btn-primary {
    background-color: var(--primary);
    color: #ffffff;
}

.btn-primary:hover:not(:disabled) {
    background-color: var(--primary-hover);
}

.btn-secondary {
    background-color: var(--secondary);
    color: #ffffff;
}

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

.btn-danger {
    background-color: var(--danger);
    color: #ffffff;
    padding: 6px 12px;
    font-size: 12px;
}

.btn-danger:hover:not(:disabled) {
    background-color: var(--danger-hover);
}

.filter-section {
    margin-bottom: 25px;
    padding: 15px;
    background-color: var(--bg-section);
    border-radius: 4px;
}

.filter-row {
    display: flex;
    gap: 20px;
    align-items: flex-start;
    flex-wrap: wrap;
}

.filter-category {
    flex: 1;
    min-width: 300px;
}

.filter-section label {
    font-weight: 600;
    margin-right: 10px;
    display: block;
    margin-bottom: 10px;
}

.filter-buttons {
    display: flex;
    gap: 10px;
}

.search-box {
    flex: 0 0 250px;
    display: flex;
    flex-direction: column;
}

.search-box input {
    width: 100%;
    padding: 8px 12px;
    border: 2px solid var(--border-secondary);
    border-radius: 4px;
    font-size: 14px;
    font-family: inherit;
    transition: border-color 0.2s;
    background-color: var(--bg-container);
    color: var(--text-primary);
}

.search-box input:focus {
    outline: none;
    border-color: var(--primary);
}

.filter-btn {
    padding: 8px 16px;
    border: 2px solid var(--border-secondary);
    background-color: var(--bg-elevated);
    color: var(--text-primary);
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.2s;
}

.filter-btn:hover {
    border-color: var(--primary);
}

.filter-btn.active {
    background-color: var(--primary);
    color: #ffffff;
    border-color: var(--primary);
}

.task-list {
    display: flex;
    flex-direction: column;
    gap: 15px;
    list-style: none;
    padding: 0;
    margin: 0;
}

.task-item {
    border: 1px solid var(--border-primary);
    border-radius: 6px;
    overflow: hidden;
    transition: box-shadow 0.2s, border-color 0.2s;
}

.task-item:hover {
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.task-item:focus-within {
    border-color: var(--primary);
    box-shadow: 0 2px 8px rgba(52, 152, 219, 0.2);
}

.task-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px;
    cursor: pointer;
    background-color: var(--bg-section);
    transition: background-color 0.2s;
}

.task-header:hover {
    background-color: var(--bg-hover);
}

.task-header:focus-visible {
    background-color: var(--bg-focus);
    outline: 2px solid var(--primary);
    outline-offset: -2px;
}

.task-header-left {
    display: flex;
    align-items: center;
    gap: 10px;
    flex: 1;
}

.expand-icon {
    font-size: 12px;
    color: var(--text-secondary);
    transition: transform 0.2s;
}

.task-item.expanded .expand-icon {
    transform: rotate(90deg);
}

.task-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-heading);
}

.task-category {
    padding: 4px 10px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    color: #ffffff;
}

.task-content {
    display: none;
    padding: 20px;
    background-color: var(--bg-elevated);
}

.task-item.expanded .task-content {
    display: block;
}

.star-field {
    margin-bottom: 20px;
    padding: 15px;
    background-color: var(--bg-section);
    border-radius: 4px;
}

.star-field-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
}

.star-field-label {
    font-weight: 600;
    color: var(--text-heading);
    text-transform: uppercase;
    font-size: 13px;
    letter-spacing: 0.5px;
    cursor: default;
}

.star-field-value {
    white-space: pre-wrap;
    line-height: 1.6;
    color: var(--text-secondary);
}

.star-field-edit {
    display: none;
}

.star-field.editing .star-field-value {
    display: none;
}

.star-field.editing .star-field-edit {
    display: block;
}

.star-field textarea {
    width: 100%;
    padding: 10px;
    border: 1px solid var(--border-secondary);
    border-radius: 4px;
    font-family: inherit;
    font-size: 14px;
    resize: vertical;
    min-height: 80px;
    background-color: var(--bg-container);
    color: var(--text-primary);
}

.star-field-actions {
    display: flex;
    gap: 8px;
    margin-top: 10px;
}

.btn-small {
    padding: 6px 12px;
    font-size: 12px;
}

.task-actions {
    display: flex;
    gap: 10px;
    padding: 15px;
    background-color: var(--bg-section);
    border-top: 1px solid var(--border-primary);
}

.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    overflow-y: auto;
}

.modal.active {
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-content {
    background-color: var(--bg-elevated);
    padding: 30px;
    border-radius: 8px;
    width: 90%;
    max-width: 600px;
    max-height: 90vh;
    overflow-y: auto;
}

.modal-large {
    max-width: 800px;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.modal-header h2 {
    font-size: 24px;
    color: var(--text-heading);
}

.close,
.close-bulk,
.close-export,
.close-category {
    background: none;
    border: none;
    font-size: 28px;
    font-weight: bold;
    color: var(--text-tertiary);
    cursor: pointer;
    line-height: 1;
    padding: 4px;
    transition: color 0.2s, background-color 0.2s;
    border-radius: 4px;
}

.close:hover,
.close-bulk:hover,
.close-export:hover,
.close-category:hover {
    color: var(--text-primary);
}

.close:focus-visible,
.close-bulk:focus-visible,
.close-export:focus-visible,
.close-category:focus-visible {
    color: var(--text-primary);
    background-color: var(--bg-focus);
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

.bulk-instructions,
.export-instructions {
    background-color: var(--bg-focus);
    padding: 15px;
    border-radius: 4px;
    margin-bottom: 20px;
    border-left: 4px solid var(--primary);
}

.bulk-instructions p,
.export-instructions p {
    margin: 0;
    font-size: 14px;
    line-height: 1.5;
    color: var(--text-heading);
}

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

.form-group label {
    display: block;
    margin-bottom: 6px;
    font-weight: 600;
    color: var(--text-heading);
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 10px;
    border: 1px solid var(--border-secondary);
    border-radius: 4px;
    font-family: inherit;
    font-size: 14px;
    background-color: var(--bg-container);
    color: var(--text-primary);
}

.form-group textarea {
    resize: vertical;
}

.form-actions {
    display: flex;
    justify-content: flex-end;
    gap: 10px;
    margin-top: 25px;
}

.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--text-tertiary);
}

.empty-state h3 {
    font-size: 20px;
    margin-bottom: 10px;
}

.empty-state p {
    font-size: 14px;
}

/* Category Management */
.category-list {
    margin-bottom: 30px;
    max-height: 300px;
    overflow-y: auto;
    list-style: none;
    padding: 0;
}

.category-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px;
    border: 1px solid var(--border-primary);
    border-radius: 4px;
    margin-bottom: 10px;
    background-color: var(--bg-section);
    transition: border-color 0.2s, box-shadow 0.2s;
}

.category-item:focus-within {
    border-color: var(--primary);
    box-shadow: 0 2px 4px rgba(52, 152, 219, 0.2);
}

.category-item-info {
    display: flex;
    align-items: center;
    gap: 12px;
}

.category-color-preview {
    width: 30px;
    height: 30px;
    border-radius: 4px;
    border: 2px solid var(--border-secondary);
}

.category-item-name {
    font-weight: 600;
    color: var(--text-heading);
}

.category-item-actions {
    display: flex;
    gap: 8px;
}

.add-category-section {
    border-top: 2px solid var(--border-primary);
    padding-top: 20px;
    margin-top: 20px;
}

.add-category-section h3 {
    font-size: 18px;
    color: var(--text-heading);
    margin-bottom: 15px;
}

/* Form help text */
.form-help {
    display: block;
    margin-top: 4px;
    color: var(--text-secondary);
    font-size: 13px;
    line-height: 1.4;
}

/* Theme Toggle Button */
.theme-toggle {
    background: var(--bg-elevated);
    border: 2px solid var(--border-primary);
    border-radius: 24px;
    width: 48px;
    height: 48px;
    padding: 0;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    position: relative;
}

.theme-toggle:hover {
    border-color: var(--primary);
    background-color: var(--bg-hover);
}

.theme-toggle:focus-visible {
    outline: 2px solid var(--border-focus);
    outline-offset: 2px;
}

.theme-toggle svg {
    width: 24px;
    height: 24px;
    fill: var(--text-primary);
    transition: transform 0.3s ease;
}

.theme-toggle:hover svg {
    transform: rotate(20deg);
}

/* Responsive Design */
@media (max-width: 768px) {
    header {
        flex-direction: column;
        align-items: flex-start;
        gap: 20px;
    }

    .header-buttons {
        width: 100%;
        justify-content: flex-start;
    }

    .filter-row {
        flex-direction: column;
    }

    .search-box {
        flex: 1;
        width: 100%;
    }

    .modal-content {
        width: 95%;
        padding: 20px;
    }

    .container {
        padding: 15px;
    }
}