:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary: #64748b;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --info: #06b6d4;
    --bg-primary: #f8fafc;
    --bg-secondary: #f1f5f9;
    --bg-card: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
    --radius: 8px;
    --radius-lg: 12px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    height: 100vh;
    overflow: hidden;
}

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

/* Header */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.5rem;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow);
}

.header-left h1 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--primary);
}

.subtitle {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.header-right {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.timer-container {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    margin-right: 0.5rem;
}

.timer-label {
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-transform: uppercase;
}

.timer {
    font-size: 1.5rem;
    font-weight: 700;
    font-variant-numeric: tabular-nums;
    color: var(--text-primary);
}

.timer.warning {
    color: var(--warning);
}

.timer.danger {
    color: var(--danger);
    animation: pulse 1s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.5rem 1rem;
    border: none;
    border-radius: var(--radius);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

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

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

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

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

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

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

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

.btn-icon {
    width: 2.5rem;
    height: 2.5rem;
    padding: 0;
    border-radius: 50%;
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 1rem;
}

.btn-small {
    padding: 0.375rem 0.75rem;
    font-size: 0.75rem;
}

/* Main Content */
.main-content {
    display: flex;
    flex: 1;
    overflow: hidden;
}

/* Sidebar */
.sidebar {
    width: 320px;
    background: var(--bg-card);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.progress-section {
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--border-color);
}

.progress-section h3 {
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--text-secondary);
    text-transform: uppercase;
}

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

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), var(--info));
    border-radius: 3px;
    transition: width 0.3s ease;
    width: 0%;
}

.progress-text {
    display: block;
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-top: 0.5rem;
}

/* Timeline Navigation */
.timeline-nav {
    flex: 1;
    overflow-y: auto;
    padding: 1rem;
}

.timeline-nav h3 {
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-secondary);
    text-transform: uppercase;
}

.phase {
    margin-bottom: 1rem;
}

.phase-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.5rem;
    padding: 0 0.25rem;
}

.phase-badge {
    font-size: 0.625rem;
    font-weight: 700;
    text-transform: uppercase;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    background: var(--bg-secondary);
    color: var(--text-secondary);
}

.phase-badge.core {
    background: var(--primary);
    color: white;
}

.phase-time {
    font-size: 0.75rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.phase-desc {
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    padding: 0 0.25rem;
    font-style: italic;
    line-height: 1.4;
}

.question-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.625rem 0.75rem;
    border-radius: var(--radius);
    cursor: pointer;
    transition: all 0.2s;
    margin-bottom: 0.25rem;
    position: relative;
}

.question-item:hover {
    background: var(--bg-secondary);
}

.question-item.active {
    background: var(--primary);
    color: white;
}

.question-item.completed {
    background: rgba(16, 185, 129, 0.1);
    border-left: 3px solid var(--success);
}

.question-item.completed .q-number,
.question-item.completed .q-title {
    color: var(--success);
}

.question-item.skipped {
    opacity: 0.7;
}

.question-item.skipped .q-title {
    text-decoration: line-through;
    color: var(--text-secondary);
}

.q-number {
    font-size: 0.625rem;
    font-weight: 700;
    width: 1.75rem;
    height: 1.75rem;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-secondary);
    border-radius: 4px;
    flex-shrink: 0;
}

.question-item.active .q-number {
    background: rgba(255, 255, 255, 0.2);
}

.q-title {
    font-size: 0.8125rem;
    font-weight: 500;
    flex: 1;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.skip-badge {
    font-size: 0.5625rem;
    font-weight: 700;
    padding: 0.125rem 0.375rem;
    background: var(--warning);
    color: white;
    border-radius: 4px;
}

.skip-badge.hidden {
    display: none;
}

/* Question Panel */
.question-panel {
    flex: 1;
    padding: 1.5rem;
    overflow-y: auto;
}

.question-container {
    max-width: 800px;
    margin: 0 auto;
}

/* Phase Intro Card */
.phase-intro {
    background: linear-gradient(135deg, var(--primary), var(--info));
    color: white;
    padding: 2rem;
    border-radius: var(--radius-lg);
    margin-bottom: 1.5rem;
}

.phase-intro h2 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.phase-intro p {
    opacity: 0.9;
}

/* Question Card */
.question-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
}

.question-header {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.question-meta {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.question-number {
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--primary);
    text-transform: uppercase;
}

.question-category {
    font-size: 0.625rem;
    padding: 0.25rem 0.5rem;
    background: var(--bg-secondary);
    border-radius: 4px;
    width: fit-content;
}

.question-priority {
    font-size: 0.625rem;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    width: fit-content;
    font-weight: 600;
}

.question-priority.critical {
    background: rgba(239, 68, 68, 0.1);
    color: var(--danger);
}

.question-priority.conditional {
    background: rgba(245, 158, 11, 0.1);
    color: var(--warning);
}

.question-priority.optional {
    background: rgba(6, 182, 212, 0.1);
    color: var(--info);
}

.question-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    flex: 1;
}

.question-content {
    font-size: 1rem;
    line-height: 1.8;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
}

/* Question Sections */
.section {
    margin-bottom: 1.5rem;
    padding: 1rem;
    background: var(--bg-secondary);
    border-radius: var(--radius);
    border-left: 4px solid var(--primary);
}

.section-title {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.section-content {
    font-size: 0.9375rem;
    color: var(--text-primary);
}

.interpretation {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-top: 0.5rem;
}

.interpretation-item {
    display: flex;
    gap: 0.5rem;
    padding: 0.5rem;
    background: white;
    border-radius: 4px;
}

.interpretation-label {
    font-weight: 600;
    color: var(--primary);
    flex-shrink: 0;
}

/* Answer Section */
.answer-section {
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 2px solid var(--border-color);
}

.answer-title {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.answer-options {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    margin-bottom: 1.5rem;
}

.answer-option {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    padding: 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius);
    cursor: pointer;
    transition: all 0.2s;
}

.answer-option:hover {
    border-color: var(--primary);
    background: rgba(37, 99, 235, 0.05);
}

.answer-option.selected {
    border-color: var(--primary);
    background: rgba(37, 99, 235, 0.1);
}

.answer-option input[type="radio"] {
    margin-top: 0.25rem;
}

.option-text {
    flex: 1;
}

.option-label {
    font-weight: 600;
    color: var(--primary);
    display: block;
    margin-bottom: 0.25rem;
}

.option-desc {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* Notes Area */
.notes-area {
    margin-top: 1.5rem;
}

.notes-area label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

.notes-input {
    width: 100%;
    min-height: 120px;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    font-family: inherit;
    font-size: 0.9375rem;
    resize: vertical;
    transition: border-color 0.2s;
}

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

/* Skip Warning */
.skip-warning {
    margin-top: 1rem;
    padding: 1rem;
    background: rgba(245, 158, 11, 0.1);
    border: 1px solid var(--warning);
    border-radius: var(--radius);
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
}

.skip-warning-icon {
    font-size: 1.25rem;
}

.skip-warning-text {
    flex: 1;
}

.skip-warning-title {
    font-weight: 600;
    color: var(--warning);
}

.skip-warning-desc {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* Actions Bar */
.actions-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.5rem;
    background: var(--bg-card);
    border-top: 1px solid var(--border-color);
}

.actions-left, .actions-right {
    display: flex;
    gap: 0.75rem;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    padding: 2rem;
}

.modal.show {
    display: flex;
}

.modal-content {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    width: 100%;
    max-width: 900px;
    max-height: 80vh;
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-lg);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.modal-header h2 {
    font-size: 1.25rem;
}

.close-btn {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-secondary);
}

.modal-body {
    padding: 1.5rem;
    overflow-y: auto;
}

/* Summary Styles */
.summary-section {
    margin-bottom: 1.5rem;
}

.summary-section h3 {
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--border-color);
}

.summary-item {
    display: flex;
    gap: 1rem;
    padding: 0.75rem;
    background: var(--bg-secondary);
    border-radius: var(--radius);
    margin-bottom: 0.5rem;
}

.summary-q-num {
    font-weight: 600;
    color: var(--primary);
    width: 2.5rem;
    flex-shrink: 0;
}

.summary-q-title {
    flex: 1;
}

.summary-answer {
    font-size: 0.875rem;
    color: var(--success);
    font-weight: 500;
}

.summary-notes {
    font-size: 0.8125rem;
    color: var(--text-secondary);
    margin-top: 0.25rem;
    font-style: italic;
}

/* Export Preview */
.export-preview {
    background: var(--bg-secondary);
    padding: 1rem;
    border-radius: var(--radius);
    font-family: 'Courier New', monospace;
    font-size: 0.8125rem;
    white-space: pre-wrap;
    max-height: 400px;
    overflow-y: auto;
}

/* Intro Screen */
.intro-screen {
    text-align: center;
    padding: 3rem 2rem;
}

.intro-screen h2 {
    font-size: 1.75rem;
    margin-bottom: 1rem;
}

.intro-screen p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.timeline-overview {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin: 2rem 0;
    text-align: left;
}

.timeline-phase {
    background: var(--bg-secondary);
    padding: 1rem;
    border-radius: var(--radius);
}

.timeline-phase h4 {
    font-size: 0.875rem;
    color: var(--primary);
    margin-bottom: 0.25rem;
}

.phase-overview-desc {
    font-size: 0.75rem;
    color: var(--text-secondary);
    font-style: italic;
    margin-bottom: 0.5rem;
    line-height: 1.4;
}

.timeline-phase ul {
    font-size: 0.8125rem;
    color: var(--text-secondary);
    padding-left: 1rem;
}

.timeline-phase li {
    margin-bottom: 0.25rem;
}

.start-btn {
    margin-top: 2rem;
    padding: 1rem 2rem;
    font-size: 1rem;
}

/* Responsive */
@media (max-width: 768px) {
    .sidebar {
        width: 100%;
        position: fixed;
        bottom: 0;
        left: 0;
        right: 0;
        height: 60%;
        transform: translateY(100%);
        transition: transform 0.3s;
        z-index: 100;
    }
    
    .sidebar.open {
        transform: translateY(0);
    }
    
    .question-panel {
        padding: 1rem;
    }
}