/**
 * CA Rule Inference Experiment - Mobile-First Sequential Design
 * 
 * Optimized for touch interaction with large targets and smooth transitions.
 */

/* ============================================
   CSS Variables
   ============================================ */

:root {
    --bg-primary: #0d1117;
    --bg-secondary: #161b22;
    --bg-card: #21262d;
    --text-primary: #f0f6fc;
    --text-secondary: #8b949e;
    --text-muted: #6e7681;
    --accent: #58a6ff;
    --accent-glow: rgba(88, 166, 255, 0.3);
    --success: #3fb950;
    --warning: #d29922;
    --border: #30363d;
    --radius: 12px;
    --radius-sm: 8px;
    --shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
    --transition: 200ms ease;
    --transition-slow: 300ms ease;
}

/* ============================================
   Reset & Base
   ============================================ */

*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

html {
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    min-height: 100dvh;
    line-height: 1.5;
    overflow-x: hidden;
}

/* ============================================
   Screen Management
   ============================================ */

.screen {
    display: none;
    min-height: 100vh;
    min-height: 100dvh;
    padding: 16px;
    padding-bottom: env(safe-area-inset-bottom, 16px);
}

.screen.active {
    display: flex;
    flex-direction: column;
}

/* ============================================
   Welcome Screen
   ============================================ */

#welcome-screen {
    justify-content: center;
    align-items: center;
}

.welcome-content {
    max-width: 400px;
    width: 100%;
    text-align: center;
}

.welcome-content h1 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent);
    margin-bottom: 4px;
}

.welcome-content h2 {
    font-size: 1.1rem;
    font-weight: 400;
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.instructions {
    text-align: left;
    margin-bottom: 24px;
}

.instructions > p {
    color: var(--text-secondary);
    margin-bottom: 12px;
    font-size: 0.95rem;
}

.instruction-box {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 16px;
}

.instruction-box p {
    margin-bottom: 8px;
    font-size: 0.9rem;
}

.instruction-box ul {
    margin: 0 0 12px 20px;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.instruction-box li {
    margin-bottom: 4px;
}

.time-estimate {
    text-align: center;
    color: var(--text-muted);
    font-size: 0.85rem !important;
    margin-bottom: 0 !important;
}

/* Steps Box - Important Instructions */
.steps-box {
    background: linear-gradient(135deg, var(--bg-card) 0%, rgba(88, 166, 255, 0.1) 100%);
    border: 2px solid var(--accent);
    border-radius: var(--radius);
    padding: 16px;
    margin-bottom: 16px;
}

.steps-box > p {
    margin-bottom: 12px;
    font-size: 1rem;
    color: var(--text-primary);
}

.steps-list {
    margin: 0 0 0 20px;
    padding: 0;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.steps-list li {
    margin-bottom: 12px;
    line-height: 1.5;
}

.steps-list li:last-child {
    margin-bottom: 0;
}

.steps-list li:nth-child(3) {
    color: var(--warning);
    font-weight: 600;
}

.video-link {
    display: inline-block;
    margin-top: 6px;
    padding: 8px 16px;
    background: var(--accent);
    color: var(--bg-primary);
    text-decoration: none;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.9rem;
    transition: var(--transition);
}

.video-link:hover {
    background: #79b8ff;
    transform: scale(1.02);
}

.video-link:active {
    transform: scale(0.98);
}

.participant-input {
    margin-bottom: 24px;
}

.participant-input label {
    display: block;
    text-align: left;
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 8px;
}

.participant-input input {
    width: 100%;
    padding: 14px 16px;
    font-size: 1rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    outline: none;
    transition: border-color var(--transition);
}

.participant-input input:focus {
    border-color: var(--accent);
}

.participant-input input::placeholder {
    color: var(--text-muted);
}

/* ============================================
   Resume Screen
   ============================================ */

#resume-screen {
    justify-content: center;
    align-items: center;
}

.resume-content {
    max-width: 400px;
    width: 100%;
    text-align: center;
}

.resume-content h1 {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--warning);
    margin-bottom: 12px;
}

.resume-message {
    color: var(--text-secondary);
    margin-bottom: 20px;
    font-size: 0.95rem;
}

.resume-info {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 16px 20px;
    margin-bottom: 24px;
}

.resume-info p {
    margin: 0;
    font-size: 0.95rem;
}

#resume-progress-info {
    color: var(--text-primary);
    font-weight: 500;
}

#resume-participant-info {
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-top: 8px;
}

.resume-buttons {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.secondary-btn {
    width: 100%;
    padding: 14px 24px;
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-primary);
    background: transparent;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    cursor: pointer;
    transition: border-color var(--transition), background var(--transition);
    -webkit-appearance: none;
}

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

.secondary-btn:active {
    background: var(--bg-card);
}

/* ============================================
   Primary Button
   ============================================ */

.primary-btn {
    width: 100%;
    padding: 16px 24px;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--bg-primary);
    background: var(--accent);
    border: none;
    border-radius: var(--radius);
    cursor: pointer;
    transition: transform var(--transition), box-shadow var(--transition);
    -webkit-appearance: none;
}

.primary-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--accent-glow);
}

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

.primary-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

/* ============================================
   Experiment Screen
   ============================================ */

#experiment-screen {
    justify-content: space-between;
    gap: 12px;
}

/* Progress Section */
.progress-section {
    flex-shrink: 0;
}

.progress-text {
    display: flex;
    justify-content: space-between;
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

#trial-progress {
    font-weight: 600;
    color: var(--text-primary);
}

.progress-bar {
    height: 6px;
    background: var(--bg-card);
    border-radius: 3px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--accent), var(--success));
    border-radius: 3px;
    transition: width var(--transition-slow);
}

/* Images Section */
.images-section {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 8px;
    min-height: 0;
}

.image-container {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 8px;
    transition: opacity var(--transition);
}

.image-label {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 6px;
    text-align: center;
}

.image-wrapper {
    background: white;
    border-radius: var(--radius-sm);
    padding: 12px 12px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.image-wrapper img {
    max-width: 100%;
    height: auto;
    max-height: 44vh;
    display: block;
}

.arrow-separator {
    text-align: center;
    color: var(--accent);
    font-size: 1rem;
    font-weight: 500;
    padding: 4px 0;
}

/* Candidate transition */
.candidate-container.transitioning {
    opacity: 0.3;
}

/* ============================================
   Rating Section
   ============================================ */

.rating-section {
    flex-shrink: 0;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 16px;
}

.rating-prompt {
    text-align: center;
    font-size: 1rem;
    font-weight: 500;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.rating-scale {
    margin-bottom: 12px;
}

.scale-labels {
    display: flex;
    justify-content: space-between;
    font-size: 0.7rem;
    color: var(--text-muted);
    margin-bottom: 10px;
    padding: 0 4px;
}

.rating-buttons {
    display: flex;
    justify-content: space-between;
    gap: 6px;
}

.rating-btn {
    flex: 1;
    aspect-ratio: 1;
    max-width: 52px;
    min-width: 44px;
    min-height: 44px;
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text-secondary);
    background: var(--bg-card);
    border: 2px solid var(--border);
    border-radius: 50%;
    cursor: pointer;
    transition: all var(--transition);
    -webkit-appearance: none;
    display: flex;
    align-items: center;
    justify-content: center;
}

.rating-btn:focus {
    outline: none;
}

/* Only apply hover styles on devices that support hover */
@media (hover: hover) {
    .rating-btn:hover {
        border-color: var(--accent);
        color: var(--text-primary);
    }
}

.rating-btn:active {
    transform: scale(0.95);
}

.rating-btn.selected {
    background: var(--accent);
    border-color: var(--accent);
    color: var(--bg-primary);
    transform: scale(1.1);
}

.rating-btn.pulse {
    animation: pulse 300ms ease;
}

@keyframes pulse {
    0% { transform: scale(1.1); }
    50% { transform: scale(1.2); box-shadow: 0 0 20px var(--accent-glow); }
    100% { transform: scale(1.1); }
}

.tap-hint {
    text-align: center;
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* ============================================
   Completion Screen
   ============================================ */

#completion-screen {
    justify-content: center;
    align-items: center;
}

.completion-content {
    max-width: 400px;
    width: 100%;
    text-align: center;
}

.completion-content h1 {
    font-size: 2rem;
    color: var(--success);
    margin-bottom: 8px;
}

.thank-you {
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.summary-box {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px;
    margin-bottom: 24px;
    text-align: left;
}

.summary-box h3 {
    text-align: center;
    color: var(--accent);
    margin-bottom: 16px;
    font-size: 1.1rem;
}

.summary-box h4 {
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    margin-top: 16px;
    margin-bottom: 10px;
}

.summary-stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
}

.stat {
    background: var(--bg-secondary);
    border-radius: var(--radius-sm);
    padding: 12px;
    text-align: center;
}

.stat-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent);
}

.stat-label {
    display: block;
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 4px;
}

.time-step-accuracy {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.time-stat {
    background: var(--bg-secondary);
    padding: 6px 10px;
    border-radius: var(--radius-sm);
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.summary-note {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-align: center;
    margin-top: 12px;
    font-style: italic;
}

.download-section {
    margin-bottom: 16px;
}

.download-section p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 12px;
}

/* ============================================
   Transition Overlay (for future use)
   ============================================ */

.transition-overlay {
    position: fixed;
    inset: 0;
    background: var(--bg-primary);
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition);
    z-index: 100;
}

.transition-overlay.active {
    opacity: 1;
    pointer-events: auto;
}

/* ============================================
   Responsive Adjustments
   ============================================ */

/* Larger phones / small tablets */
@media (min-width: 400px) {
    .rating-btn {
        max-width: 56px;
        font-size: 1.3rem;
    }
    
    .image-wrapper img {
        max-height: 44vh;
    }
}

/* Tablets and desktop */
@media (min-width: 768px) {
    .screen {
        padding: 24px;
    }
    
    .welcome-content,
    .completion-content {
        max-width: 500px;
    }
    
    #experiment-screen {
        max-width: 600px;
        margin: 0 auto;
    }
    
    .image-wrapper img {
        max-height: 44vh;
    }
    
    .rating-btn {
        max-width: 64px;
        min-width: 56px;
        min-height: 56px;
        font-size: 1.4rem;
    }
    
    .rating-buttons {
        gap: 10px;
    }
}

/* Desktop */
@media (min-width: 1024px) {
    .images-section {
        flex-direction: row;
        align-items: stretch;
        gap: 16px;
    }
    
    .image-container {
        flex: 1;
    }
    
    .arrow-separator {
        display: flex;
        align-items: center;
        padding: 0 8px;
    }
    
    .arrow-separator span {
        transform: rotate(-90deg);
        white-space: nowrap;
    }
    
    .image-wrapper img {
        max-height: 50vh;
    }
}

/* Landscape mode on phones */
@media (max-height: 500px) and (orientation: landscape) {
    .images-section {
        flex-direction: row;
        gap: 12px;
    }
    
    .image-container {
        flex: 1;
    }
    
    .arrow-separator {
        display: flex;
        align-items: center;
        padding: 0 4px;
    }
    
    .image-wrapper img {
        max-height: 28vh;
    }
    
    .rating-section {
        padding: 12px;
    }
    
    .rating-prompt {
        font-size: 0.9rem;
        margin-bottom: 10px;
    }
    
    .rating-btn {
        min-width: 40px;
        min-height: 40px;
        max-width: 44px;
    }
}

/* Very small screens */
@media (max-width: 340px) {
    .rating-btn {
        min-width: 38px;
        min-height: 38px;
        font-size: 1rem;
    }
    
    .scale-labels {
        font-size: 0.6rem;
    }
}

/* Reduce motion for accessibility */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
    }
}