/* TaskMaster AI - Enhanced UI Styles */
:root {
    /* Light Theme Colors */
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --secondary-color: #6b7280;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --info-color: #3b82f6;

    /* Background Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --bg-hover: #f8fafc;

    /* Text Colors */
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;

    /* Border Colors */
    --border-light: #e2e8f0;
    --border-medium: #cbd5e1;
    --border-dark: #94a3b8;

    /* Shadow */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
}

/* Dark Theme */
[data-theme="dark"] {
    --primary-color: #6366f1;
    --primary-hover: #5b21b6;
    --secondary-color: #9ca3af;
    --success-color: #34d399;
    --warning-color: #fbbf24;
    --danger-color: #f87171;
    --info-color: #60a5fa;

    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --bg-hover: #475569;

    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;

    --border-light: #334155;
    --border-medium: #475569;
    --border-dark: #64748b;
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-secondary);
    min-height: 100vh;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Header Styles */
.header {
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-light);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
}

.header-content {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--spacing-md) var(--spacing-lg);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header-left {
    display: flex;
    align-items: center;
}

.app-title {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
}

.app-icon {
    font-size: var(--font-size-3xl);
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}

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

/* Button Styles */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-md);
    border: none;
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.2s ease;
    white-space: nowrap;
    position: relative;
    overflow: hidden;
}

.btn:before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.5s;
}

.btn:hover:before {
    left: 100%;
}

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

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

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

.btn--secondary:hover {
    background: var(--bg-hover);
    border-color: var(--border-medium);
}

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

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

.btn--sm {
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: var(--font-size-xs);
}

/* Layout */
.main-container {
    max-width: 1400px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 280px 1fr 320px;
    gap: var(--spacing-lg);
    padding: var(--spacing-lg);
    min-height: calc(100vh - 140px);
}

/* Sidebar Styles */
.sidebar {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-light);
    height: fit-content;
    position: sticky;
    top: 100px;
}

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

.sidebar-section:last-child {
    margin-bottom: 0;
}

.sidebar-section h3 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--primary-color);
}

/* Filter Buttons */
.filter-btn {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-sm) var(--spacing-md);
    margin-bottom: var(--spacing-xs);
    background: transparent;
    border: none;
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s ease;
}

.filter-btn:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
    transform: translateX(4px);
}

.filter-btn.active {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-hover));
    color: white;
    box-shadow: var(--shadow-sm);
}

.filter-btn .filter-icon {
    margin-right: var(--spacing-sm);
}

.filter-count {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    padding: 2px 6px;
    border-radius: 10px;
    font-size: var(--font-size-xs);
    font-weight: 500;
}

.filter-btn.active .filter-count {
    background: rgba(255, 255, 255, 0.2);
    color: white;
}

/* Priority Dots */
.priority-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    margin-right: var(--spacing-sm);
}

.priority-high { background: var(--danger-color); }
.priority-medium { background: var(--warning-color); }
.priority-low { background: var(--success-color); }

/* Statistics */
.stats-section {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-hover));
    margin: 0 -var(--spacing-lg);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    color: white;
}

.stats-section h3 {
    color: white;
    border-color: rgba(255, 255, 255, 0.3);
}

.stats-grid {
    display: grid;
    gap: var(--spacing-md);
}

.stat-item {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: var(--font-size-2xl);
    font-weight: 700;
    line-height: 1;
}

.stat-label {
    font-size: var(--font-size-xs);
    opacity: 0.9;
}

/* Main Content */
.main-content {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-light);
}

/* Task Controls */
.task-controls {
    display: grid;
    grid-template-columns: 1fr auto auto;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
    align-items: center;
}

.search-container {
    position: relative;
}

.search-input {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md) var(--spacing-sm) 40px;
    border: 1px solid var(--border-medium);
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    background: var(--bg-secondary);
    transition: all 0.2s ease;
}

.search-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.search-icon {
    position: absolute;
    left: 12px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
}

.sort-select {
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid var(--border-medium);
    border-radius: var(--radius-md);
    background: var(--bg-secondary);
    font-size: var(--font-size-sm);
    cursor: pointer;
}

/* Quick Add Form */
.quick-add-form {
    background: var(--bg-secondary);
    border: 2px dashed var(--border-medium);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
    transition: all 0.2s ease;
}

.quick-add-form:hover {
    border-color: var(--primary-color);
    background: var(--bg-hover);
}

.quick-add-inputs {
    display: flex;
    gap: var(--spacing-md);
}

.quick-task-input {
    flex: 1;
    padding: var(--spacing-md);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-md);
    font-size: var(--font-size-base);
    background: var(--bg-primary);
}

/* Task List */
.task-list-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--border-light);
}

.task-list-header h2 {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    color: var(--text-primary);
}

.bulk-actions {
    display: flex;
    gap: var(--spacing-sm);
}

/* Task Items */
.task-item {
    background: var(--bg-secondary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    transition: all 0.2s ease;
    position: relative;
    overflow: hidden;
}

.task-item:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
    border-color: var(--primary-color);
}

.task-item.completed {
    opacity: 0.7;
    background: var(--bg-hover);
}

.task-item.overdue {
    border-left: 4px solid var(--danger-color);
}

.task-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-sm);
}

.task-title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--text-primary);
    margin: 0;
}

.task-actions {
    display: flex;
    gap: var(--spacing-xs);
}

.task-meta {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

.task-description {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
    line-height: 1.5;
}

/* AI Assistant */
.ai-assistant {
    display: none;
}

.ai-assistant.active {
    display: block;
}

.ai-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--border-light);
}

.ai-chat {
    max-height: 400px;
    overflow-y: auto;
    margin-bottom: var(--spacing-lg);
    padding-right: var(--spacing-xs);
}

.ai-message {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.ai-avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--primary-color);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-sm);
    flex-shrink: 0;
}

.ai-content {
    background: var(--bg-secondary);
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    flex: 1;
    font-size: var(--font-size-sm);
    line-height: 1.5;
}

.ai-message--user .ai-content {
    background: var(--primary-color);
    color: white;
}

/* Modal Styles */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}

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

.modal-content {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    width: 90%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-xl);
    transform: scale(0.9);
    transition: transform 0.3s ease;
}

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

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-xl);
    border-bottom: 1px solid var(--border-light);
}

.modal-body {
    padding: var(--spacing-xl);
}

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

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

.form-control {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid var(--border-medium);
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    background: var(--bg-secondary);
    transition: border-color 0.2s ease;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-md);
}

.modal-actions {
    display: flex;
    gap: var(--spacing-md);
    justify-content: flex-end;
    margin-top: var(--spacing-xl);
}

/* Footer */
.footer {
    background: var(--bg-primary);
    border-top: 1px solid var(--border-light);
    padding: var(--spacing-lg);
    margin-top: auto;
}

.footer-content {
    max-width: 1400px;
    margin: 0 auto;
    text-align: center;
}

.footer-stats {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-md);
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

.footer-separator {
    color: var(--text-muted);
}

/* Utility Classes */
.hidden { display: none !important; }
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

/* Responsive Design */
@media (max-width: 1200px) {
    .main-container {
        grid-template-columns: 240px 1fr;
        gap: var(--spacing-md);
    }

    .sidebar-right {
        display: none;
    }
}

@media (max-width: 768px) {
    .main-container {
        grid-template-columns: 1fr;
        padding: var(--spacing-md);
    }

    .sidebar-left {
        order: 2;
        position: static;
    }

    .main-content {
        order: 1;
        padding: var(--spacing-lg);
    }

    .task-controls {
        grid-template-columns: 1fr;
        gap: var(--spacing-sm);
    }

    .quick-add-inputs {
        flex-direction: column;
    }

    .header-content {
        padding: var(--spacing-sm) var(--spacing-md);
    }

    .app-title {
        font-size: var(--font-size-xl);
    }
}

@media (max-width: 480px) {
    .modal-content {
        width: 95%;
        margin: var(--spacing-md);
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .footer-stats {
        flex-direction: column;
        gap: var(--spacing-xs);
    }
}

/* Animation Classes */
.fade-in {
    animation: fadeIn 0.3s ease;
}

.slide-up {
    animation: slideUp 0.3s ease;
}

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

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

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 6px;
}

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

::-webkit-scrollbar-thumb {
    background: var(--border-medium);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--border-dark);
}

/* Loading States */
.loading {
    position: relative;
    overflow: hidden;
}

.loading::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    animation: shimmer 2s infinite;
}

@keyframes shimmer {
    0% { left: -100%; }
    100% { left: 100%; }
}