/* CSS Variables */
:root {
    --primary-color: #3b82f6;
    --primary-hover: #2563eb;
    --secondary-color: #6b7280;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --background: #f8fafc;
    --surface: #ffffff;
    --border: #e2e8f0;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-light: #94a3b8;
    --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 12px -2px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 10px 20px -5px rgba(0, 0, 0, 0.1);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --spacing-xs: 6px;
    --spacing-sm: 10px;
    --spacing-md: 18px;
    --spacing-lg: 28px;
    --spacing-xl: 40px;
}

/* Dark Mode Colors */
body.dark-mode {
    --primary-color: #60a5fa;
    --primary-hover: #3b82f6;
    --secondary-color: #9ca3af;
    --success-color: #34d399;
    --warning-color: #fbbf24;
    --danger-color: #f87171;
    --background: #111827;
    --surface: #1f2937;
    --border: #374151;
    --text-primary: #f9fafb;
    --text-secondary: #d1d5db;
    --text-light: #9ca3af;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
}

/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    font-size: 15px;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--background);
    overflow-x: hidden;
}

/* Header */
.header {
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: var(--spacing-md) var(--spacing-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    box-shadow: var(--shadow-sm);
}

.header-left {
    flex: 0 0 auto;
}

.header-title {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 2px;
}

.header-subtitle {
    font-size: 12px;
    color: var(--text-secondary);
}

.header-stats {
    display: flex;
    gap: var(--spacing-lg);
    flex: 0 0 auto;
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--background);
    border-radius: var(--radius-md);
    min-width: 80px;
}

.stat-label {
    font-size: 11px;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.stat-value {
    font-size: 18px;
    font-weight: 600;
    color: var(--primary-color);
}

.header-actions {
    display: flex;
    gap: var(--spacing-sm);
    margin-left: auto;
    align-items: center;
}

/* Add Activity Button */
#add-activity-btn {
    display: flex;
    align-items: center;
    gap: 4px;
}

.add-icon {
    font-size: 1.3em;
    font-weight: bold;
    line-height: 1;
}

/* Mobile Menu Button */
.mobile-menu-btn {
    display: none;
    font-size: 20px;
}

/* Mobile Sidebar Overlay */
.mobile-sidebar-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 998;
}

.mobile-sidebar-overlay.active {
    display: block;
}

/* Mobile Sidebar Close Button */
.mobile-sidebar-close {
    display: none;
    position: absolute;
    top: 12px;
    right: 12px;
    background: transparent;
    border: none;
    font-size: 32px;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0;
    width: 32px;
    height: 32px;
    line-height: 32px;
    text-align: center;
    z-index: 1000;
}

.mobile-sidebar-close:hover {
    color: var(--text-primary);
}

/* Sync Status */
.sync-status-container {
    display: flex;
    align-items: center;
    padding: 6px 12px;
    background: var(--background);
    border-radius: var(--radius-md);
}

.sync-status {
    font-size: 11px;
    color: var(--text-secondary);
    white-space: nowrap;
}

/* Main Layout */
.main-layout {
    display: grid;
    grid-template-columns: 280px 1fr;
    height: calc(100vh - 89px);
    overflow: hidden;
}

/* Sidebar */
.sidebar {
    background: var(--surface);
    border-right: 1px solid var(--border);
    padding: var(--spacing-lg);
    overflow-y: auto;
}

.sidebar-section {
    margin-bottom: var(--spacing-lg);
}

.sidebar-title-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-md);
}

.sidebar-title {
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    color: var(--text-secondary);
    letter-spacing: 0.5px;
    margin: 0;
}

.sidebar-collapse-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 12px;
    padding: 4px;
    transition: transform 0.2s ease;
}

.sidebar-collapse-btn:hover {
    color: var(--text-primary);
}

.sidebar-collapse-btn.collapsed {
    transform: rotate(-90deg);
}

.category-section-content {
    max-height: 1000px;
    overflow: hidden;
    transition: max-height 0.3s ease, opacity 0.3s ease;
    opacity: 1;
}

.category-section-content.collapsed {
    max-height: 0;
    opacity: 0;
}

.category-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

/* Main Content */
.main-content {
    padding: var(--spacing-lg);
    overflow-y: auto;
    background: var(--background);
}

/* Filters */
.filters {
    background: var(--surface);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-lg);
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
    align-items: center;
    box-shadow: var(--shadow-sm);
}

.filter-group {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.filter-group label {
    font-size: 13px;
    color: var(--text-secondary);
    font-weight: 500;
}

.filter-select {
    padding: 6px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--surface);
    color: var(--text-primary);
    font-size: 13px;
    cursor: pointer;
}

.filter-select:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* Activity List */
.activity-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 60px var(--spacing-lg);
    background: var(--surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.empty-state-icon {
    font-size: 64px;
    margin-bottom: var(--spacing-md);
    opacity: 0.7;
}

.empty-state h2 {
    font-size: 24px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
}

.empty-state p {
    font-size: 16px;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.6;
}

/* Buttons */
.btn {
    padding: 10px 18px;
    border: none;
    border-radius: var(--radius-md);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.btn:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

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

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

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

.btn-secondary {
    background: var(--surface);
    color: var(--text-primary);
    border: 1px solid var(--border);
}

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

.btn-danger {
    background: var(--danger-color);
    color: white;
}

.btn-danger:hover {
    background: #dc2626;
}

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

.btn-icon {
    padding: 8px;
    font-size: 16px;
    background: var(--surface);
    border: 1px solid var(--border);
}

.btn-icon:hover {
    background: var(--background);
}

.btn-block {
    width: 100%;
    justify-content: center;
    margin-bottom: var(--spacing-sm);
}

/* Inputs */
.search-input {
    padding: 8px 16px;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    font-size: 13px;
    width: 300px;
    background: var(--surface);
}

.search-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.form-input,
.form-textarea,
.form-select {
    width: 100%;
    padding: 8px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 13px;
    font-family: inherit;
    background: var(--surface);
    color: var(--text-primary);
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.form-textarea {
    resize: vertical;
}

.form-color {
    width: 60px;
    height: 40px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    cursor: pointer;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    cursor: pointer;
    user-select: none;
}

.checkbox-label input[type="checkbox"] {
    cursor: pointer;
}

/* Form Groups */
.form-group {
    margin-bottom: var(--spacing-md);
}

.form-group label {
    display: block;
    font-size: 13px;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--background);
}

::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-light);
}

/* Responsive */
@media (max-width: 1024px) {
    .main-layout {
        grid-template-columns: 240px 1fr;
    }

    .header {
        flex-wrap: wrap;
        padding: var(--spacing-md);
    }

    .header-actions {
        width: 100%;
        margin-top: var(--spacing-sm);
        justify-content: space-between;
    }

    .search-input {
        flex: 1;
        max-width: 200px;
    }
}

@media (max-width: 768px) {
    .header {
        padding: var(--spacing-sm);
        position: relative;
    }

    .header-left {
        display: flex;
        align-items: center;
        gap: var(--spacing-xs);
        margin-bottom: var(--spacing-sm);
        padding-right: 100px; /* Space for settings + sign out buttons */
    }

    /* Mobile menu button on left */
    .mobile-menu-btn {
        display: inline-flex !important;
        flex-shrink: 0;
    }

    .header-title {
        font-size: 16px;
        margin-bottom: 0;
    }

    .header-subtitle {
        display: none; /* Hide subtitle on mobile to save space */
    }

    .header-stats {
        display: none;
    }

    /* Settings button in top right */
    #settings-btn {
        position: absolute !important;
        top: var(--spacing-sm);
        right: var(--spacing-sm);
        order: -2 !important;
        padding: 6px !important;
        font-size: 16px !important;
    }

    /* User menu fixed in top right corner next to settings */
    #user-menu {
        position: absolute !important;
        top: var(--spacing-sm);
        right: 46px; /* After settings button */
        margin: 0 !important;
        gap: 4px !important;
    }

    #user-email {
        display: none !important;
    }

    #sign-out-btn {
        padding: 6px 10px !important;
    }

    /* Auth button also in top right */
    #auth-btn {
        position: absolute !important;
        top: var(--spacing-sm);
        right: 46px; /* After settings button */
        padding: 6px 12px;
    }

    /* Action buttons row with search on left */
    .header-actions {
        flex-wrap: wrap;
        gap: var(--spacing-xs);
    }

    .search-input {
        flex: 1;
        min-width: 120px;
        font-size: 13px;
        order: 0;
    }

    #add-activity-btn {
        white-space: nowrap;
        padding: 6px 10px;
        order: 1;
    }

    #stats-btn {
        order: 2;
    }

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

    .btn-icon {
        padding: 6px;
        font-size: 16px;
    }

    .main-layout {
        grid-template-columns: 1fr;
        height: calc(100vh - 140px);
    }

    /* Mobile sidebar */
    .sidebar {
        position: fixed;
        top: 0;
        left: -280px;
        bottom: 0;
        width: 280px;
        z-index: 999;
        transition: left 0.3s ease;
        box-shadow: var(--shadow-lg);
        overflow-y: auto;
    }

    .sidebar.mobile-open {
        left: 0;
    }

    /* Show close button on mobile */
    .mobile-sidebar-close {
        display: block;
    }

    /* Add mobile stats to sidebar */
    .sidebar::before {
        content: '';
        display: block;
        padding: var(--spacing-lg);
        border-bottom: 1px solid var(--border);
        background: var(--background);
    }

    .sidebar.mobile-open::before {
        content: 'Completion: ' attr(data-completion) ' • Streak: ' attr(data-streak);
        font-size: 12px;
        color: var(--text-secondary);
        text-align: center;
    }

    .filters {
        flex-direction: column;
        align-items: stretch;
    }

    .filter-group {
        width: 100%;
        justify-content: space-between;
    }

    .activity-card {
        padding: var(--spacing-sm);
    }

    .activity-card-actions {
        flex-direction: column;
        gap: var(--spacing-xs);
    }

    .activity-card-actions button {
        width: 100%;
    }
}

@media (max-width: 480px) {
    .header-actions {
        gap: 6px;
    }

    #add-activity-btn {
        padding: 6px 10px;
    }

    .modal-content {
        width: 95%;
        max-height: 95vh;
    }

    .stat-item {
        min-width: 60px;
        padding: 6px 12px;
    }

    .stat-value {
        font-size: 16px;
    }

    .stat-label {
        font-size: 10px;
    }
}

/* Font Size Options */
body.font-small {
    font-size: 13px;
}

body.font-small .header-title {
    font-size: 18px;
}

body.font-small .btn {
    font-size: 12px;
    padding: 7px 14px;
}

body.font-small .form-input,
body.font-small .form-textarea,
body.font-small .form-select {
    font-size: 13px;
    padding: 8px 12px;
}

body.font-small .activity-card-title {
    font-size: 13px;
}

body.font-small .activity-card-description,
body.font-small .activity-notes {
    font-size: 11px;
}

body.font-small .activity-badge {
    font-size: 9px;
}

body.font-small .sidebar-title,
body.font-small .category-name {
    font-size: 12px;
}

body.font-small .command-bar-input {
    font-size: 14px;
}

body.font-small .command-bar-hint {
    font-size: 10px;
}

body.font-small .stat-label {
    font-size: 9px;
}

body.font-small .stat-value {
    font-size: 13px;
}

body.font-small .header-subtitle {
    font-size: 11px;
}

body.font-small .search-input {
    font-size: 12px;
}

body.font-large {
    font-size: 16px;
}

body.font-large .header-title {
    font-size: 22px;
}

body.font-large .btn {
    font-size: 15px;
    padding: 10px 18px;
}

body.font-large .form-input,
body.font-large .form-textarea,
body.font-large .form-select {
    font-size: 16px;
    padding: 10px 14px;
}

body.font-large .activity-card-title {
    font-size: 16px;
}

body.font-large .activity-card-description,
body.font-large .activity-notes {
    font-size: 14px;
}

body.font-large .activity-badge {
    font-size: 12px;
}

body.font-large .sidebar-title,
body.font-large .category-name {
    font-size: 14px;
}

body.font-large .command-bar-input {
    font-size: 17px;
}

body.font-large .command-bar-hint {
    font-size: 13px;
}

body.font-large .stat-label {
    font-size: 11px;
}

body.font-large .stat-value {
    font-size: 17px;
}

body.font-large .header-subtitle {
    font-size: 13px;
}

body.font-large .search-input {
    font-size: 15px;
}

body.font-xlarge {
    font-size: 18px;
}

body.font-xlarge .header-title {
    font-size: 24px;
}

body.font-xlarge .btn {
    font-size: 17px;
    padding: 12px 20px;
}

body.font-xlarge .form-input,
body.font-xlarge .form-textarea,
body.font-xlarge .form-select {
    font-size: 18px;
    padding: 12px 16px;
}

body.font-xlarge .activity-card-title {
    font-size: 18px;
}

body.font-xlarge .activity-card-description,
body.font-xlarge .activity-notes {
    font-size: 15px;
}

body.font-xlarge .activity-badge {
    font-size: 13px;
}

body.font-xlarge .sidebar-title,
body.font-xlarge .category-name {
    font-size: 15px;
}

body.font-xlarge .command-bar-input {
    font-size: 19px;
}

body.font-xlarge .command-bar-hint {
    font-size: 14px;
}

body.font-xlarge .stat-label {
    font-size: 12px;
}

body.font-xlarge .stat-value {
    font-size: 19px;
}

body.font-xlarge .header-subtitle {
    font-size: 15px;
}

body.font-xlarge .search-input {
    font-size: 17px;
}

body.font-xxlarge {
    font-size: 20px;
}

body.font-xxlarge .header-title {
    font-size: 26px;
}

body.font-xxlarge .btn {
    font-size: 19px;
    padding: 13px 22px;
}

body.font-xxlarge .form-input,
body.font-xxlarge .form-textarea,
body.font-xxlarge .form-select {
    font-size: 20px;
    padding: 14px 18px;
}

body.font-xxlarge .activity-card-title {
    font-size: 20px;
}

body.font-xxlarge .activity-card-description,
body.font-xxlarge .activity-notes {
    font-size: 17px;
}

body.font-xxlarge .activity-badge {
    font-size: 14px;
}

body.font-xxlarge .sidebar-title,
body.font-xxlarge .category-name {
    font-size: 17px;
}

body.font-xxlarge .command-bar-input {
    font-size: 21px;
}

body.font-xxlarge .command-bar-hint {
    font-size: 16px;
}

body.font-xxlarge .stat-label {
    font-size: 13px;
}

body.font-xxlarge .stat-value {
    font-size: 21px;
}

body.font-xxlarge .header-subtitle {
    font-size: 17px;
}

body.font-xxlarge .search-input {
    font-size: 19px;
}

body.font-xxxlarge {
    font-size: 22px;
}

body.font-xxxlarge .header-title {
    font-size: 28px;
}

body.font-xxxlarge .btn {
    font-size: 21px;
    padding: 14px 24px;
}

body.font-xxxlarge .form-input,
body.font-xxxlarge .form-textarea,
body.font-xxxlarge .form-select {
    font-size: 22px;
    padding: 16px 20px;
}

body.font-xxxlarge .activity-card-title {
    font-size: 22px;
}

body.font-xxxlarge .activity-card-description,
body.font-xxxlarge .activity-notes {
    font-size: 19px;
}

body.font-xxxlarge .activity-badge {
    font-size: 16px;
}

body.font-xxxlarge .sidebar-title,
body.font-xxxlarge .category-name {
    font-size: 19px;
}

body.font-xxxlarge .command-bar-input {
    font-size: 23px;
}

body.font-xxxlarge .command-bar-hint {
    font-size: 18px;
}

body.font-xxxlarge .stat-label {
    font-size: 15px;
}

body.font-xxxlarge .stat-value {
    font-size: 23px;
}

body.font-xxxlarge .header-subtitle {
    font-size: 19px;
}

body.font-xxxlarge .search-input {
    font-size: 21px;
}