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

:root {
    /* Color Palette */
    --primary-blue: #2196F3;
    --success-green: #4CAF50;
    --warning-yellow: #FFC107;
    --error-red: #F44336;
    --accent-purple: #9C27B0;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, var(--primary-blue), var(--accent-purple));
    --gradient-success: linear-gradient(135deg, var(--success-green), var(--primary-blue));
    --gradient-warning: linear-gradient(135deg, var(--warning-yellow), #FF9800);
    --gradient-error: linear-gradient(135deg, var(--error-red), #E91E63);
    
    /* Light Theme */
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-card: #ffffff;
    --text-primary: #333333;
    --text-secondary: #666666;
    --border-color: #e0e0e0;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.15);
    
    /* Typography */
    --font-family: 'Segoe UI', Tahoma, Geneva, Verdana, 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: 2rem;
    
    /* 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: 0.25rem;
    --radius-md: 0.5rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* Dark Theme */
[data-theme="dark"] {
    --bg-primary: #1a1a1a;
    --bg-secondary: #2d2d2d;
    --bg-card: #333333;
    --text-primary: #ffffff;
    --text-secondary: #cccccc;
    --border-color: #444444;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
    --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.4);
}

/* Base Styles */
body {
    font-family: var(--font-family);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: all var(--transition-normal);
}

.app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header Styles */
.header {
    background: var(--gradient-primary);
    color: white;
    padding: var(--spacing-md) 0;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: var(--font-size-2xl);
    font-weight: bold;
    margin: 0;
}

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

.nav-btn, .theme-toggle {
    background: rgba(255, 255, 255, 0.2);
    border: none;
    color: white;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    font-size: var(--font-size-sm);
}

.nav-btn:hover, .theme-toggle:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.nav-btn.active {
    background: rgba(255, 255, 255, 0.4);
    font-weight: bold;
}

.theme-toggle {
    font-size: var(--font-size-lg);
    padding: var(--spacing-sm);
    border-radius: 50%;
}

/* Main Content */
.main-content {
    flex: 1;
    padding: var(--spacing-xl) 0;
}

.screen {
    display: none;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.screen.active {
    display: block;
}

.screen-content {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow);
    transition: all var(--transition-normal);
}

.screen-title {
    font-size: var(--font-size-3xl);
    text-align: center;
    margin-bottom: var(--spacing-xl);
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Check-in Screen */
.checkin-container {
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
}

.mood-selector, .energy-selector {
    margin-bottom: var(--spacing-xl);
}

.mood-selector h3, .energy-selector h3 {
    font-size: var(--font-size-xl);
    margin-bottom: var(--spacing-lg);
    color: var(--text-primary);
}

.mood-options, .energy-options {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

.mood-btn, .energy-btn {
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    cursor: pointer;
    transition: all var(--transition-normal);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-sm);
    min-width: 80px;
}

.mood-btn:hover, .energy-btn:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.mood-btn.selected {
    border-color: var(--primary-blue);
    background: linear-gradient(135deg, var(--primary-blue), rgba(33, 150, 243, 0.1));
    color: white;
}

.energy-btn.selected {
    border-color: var(--success-green);
    background: linear-gradient(135deg, var(--success-green), rgba(76, 175, 80, 0.1));
    color: white;
}

.mood-btn span, .energy-btn span {
    font-size: var(--font-size-sm);
    font-weight: 500;
}

.inspiration-box {
    background: var(--gradient-success);
    color: white;
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    margin: var(--spacing-xl) 0;
    text-align: center;
    font-style: italic;
    min-height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Buttons */
.primary-btn, .secondary-btn {
    padding: var(--spacing-md) var(--spacing-xl);
    border: none;
    border-radius: var(--radius-md);
    font-size: var(--font-size-base);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-normal);
    text-decoration: none;
    display: inline-block;
    text-align: center;
}

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

.primary-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

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

.secondary-btn {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 2px solid var(--border-color);
}

.secondary-btn:hover {
    background: var(--border-color);
    transform: translateY(-2px);
}

/* Tasks Screen */
.tasks-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xl);
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.tasks-controls {
    display: flex;
    gap: var(--spacing-md);
    align-items: center;
}

.filter-select {
    padding: var(--spacing-sm) var(--spacing-md);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-card);
    color: var(--text-primary);
    font-size: var(--font-size-sm);
}

.suggested-tasks, .all-tasks {
    margin-bottom: var(--spacing-xl);
}

.suggested-tasks h3, .all-tasks h3 {
    font-size: var(--font-size-xl);
    margin-bottom: var(--spacing-lg);
    color: var(--text-primary);
}

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

.task-item {
    background: var(--bg-card);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    transition: all var(--transition-normal);
    cursor: pointer;
}

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

.task-item.completed {
    opacity: 0.7;
    text-decoration: line-through;
}

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

.task-name {
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin: 0;
}

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

.task-action-btn {
    background: none;
    border: none;
    font-size: var(--font-size-lg);
    cursor: pointer;
    padding: var(--spacing-xs);
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

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

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

.task-tag {
    background: var(--bg-secondary);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    font-size: var(--font-size-xs);
}

.effort-low { border-left: 4px solid var(--success-green); }
.effort-medium { border-left: 4px solid var(--warning-yellow); }
.effort-high { border-left: 4px solid var(--error-red); }

/* Focus Mode */
.focus-container {
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
}

.current-task {
    background: var(--bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-xl);
}

.current-task h3 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
}

.current-task p {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--text-primary);
}

.timer-container {
    margin-bottom: var(--spacing-xl);
}

.timer-display {
    font-size: 4rem;
    font-weight: bold;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-lg);
    font-family: 'Courier New', monospace;
}

.timer-controls {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

.timer-btn {
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-normal);
    font-size: var(--font-size-base);
}

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

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

.timer-settings {
    display: flex;
    gap: var(--spacing-lg);
    justify-content: center;
    margin-bottom: var(--spacing-xl);
    flex-wrap: wrap;
}

.setting-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.setting-group label {
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--text-secondary);
}

.setting-group input {
    padding: var(--spacing-sm);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-card);
    color: var(--text-primary);
    text-align: center;
    width: 80px;
}

.ambient-sounds h3 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.sound-options {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

.sound-btn {
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-normal);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    min-width: 80px;
}

.sound-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.sound-btn.active {
    border-color: var(--primary-blue);
    background: var(--primary-blue);
    color: white;
}

/* Statistics */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-xl);
}

.stat-card {
    background: var(--bg-card);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow);
}

.stat-card h3 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
    text-align: center;
}

.stat-card canvas {
    max-width: 100%;
    height: auto;
}

.insights p {
    margin-bottom: var(--spacing-sm);
    padding: var(--spacing-sm);
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    animation: fadeIn 0.3s ease;
}

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

.modal-content {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    max-width: 500px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-hover);
    animation: slideIn 0.3s ease;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-lg);
    border-bottom: 2px solid var(--border-color);
}

.modal-header h3 {
    margin: 0;
    font-size: var(--font-size-xl);
}

.close-btn {
    background: none;
    border: none;
    font-size: var(--font-size-2xl);
    cursor: pointer;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

.close-btn:hover {
    color: var(--error-red);
}

.task-form {
    padding: var(--spacing-lg);
}

.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-group label {
    display: block;
    margin-bottom: var(--spacing-sm);
    font-weight: 600;
    color: var(--text-primary);
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: var(--spacing-md);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-card);
    color: var(--text-primary);
    font-size: var(--font-size-base);
    transition: border-color var(--transition-fast);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-blue);
}

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

/* Footer */
.footer {
    background: var(--bg-secondary);
    color: var(--text-secondary);
    text-align: center;
    padding: var(--spacing-lg);
    border-top: 2px solid var(--border-color);
    font-size: var(--font-size-sm);
}

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

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

/* Responsive Design */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .nav {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .screen-content {
        padding: var(--spacing-lg);
    }
    
    .tasks-header {
        flex-direction: column;
        align-items: stretch;
    }
    
    .tasks-controls {
        justify-content: center;
    }
    
    .mood-options,
    .energy-options {
        gap: var(--spacing-sm);
    }
    
    .mood-btn,
    .energy-btn {
        min-width: 60px;
        padding: var(--spacing-md);
    }
    
    .timer-display {
        font-size: 3rem;
    }
    
    .timer-settings {
        flex-direction: column;
        align-items: center;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .form-actions {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .main-content {
        padding: var(--spacing-lg) 0;
    }
    
    .screen-content {
        padding: var(--spacing-md);
        margin: 0 var(--spacing-sm);
    }
    
    .timer-display {
        font-size: 2.5rem;
    }
    
    .mood-options,
    .energy-options,
    .sound-options {
        grid-template-columns: repeat(2, 1fr);
        display: grid;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus styles for accessibility */
button:focus,
input:focus,
select:focus {
    outline: 2px solid var(--primary-blue);
    outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --border-color: #000000;
        --shadow: 0 2px 10px rgba(0, 0, 0, 0.5);
    }
}

/* Print styles */
@media print {
    .header,
    .footer,
    .modal,
    button {
        display: none !important;
    }
    
    .screen {
        display: block !important;
    }
    
    .screen-content {
        box-shadow: none;
        border: 1px solid #000;
    }
}