/* QA/QC Study App Styles */
:root {
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --bg-color: #f1f5f9;
    --card-bg: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
    --radius: 12px;
    --radius-sm: 8px;
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

/* App Container */
.app-container {
    display: flex;
    min-height: 100vh;
}

/* Sidebar */
.sidebar {
    width: 280px;
    background: var(--card-bg);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
    z-index: 100;
}

.logo {
    padding: 24px;
    display: flex;
    align-items: center;
    gap: 12px;
    border-bottom: 1px solid var(--border-color);
}

.logo i {
    font-size: 28px;
    color: var(--primary-color);
}

.logo span {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-primary);
}

.nav-menu {
    list-style: none;
    padding: 16px 0;
    flex: 1;
}

.nav-menu li {
    padding: 14px 24px;
    display: flex;
    align-items: center;
    gap: 12px;
    cursor: pointer;
    transition: var(--transition);
    margin: 4px 12px;
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
}

.nav-menu li:hover {
    background: #f8fafc;
    color: var(--primary-color);
}

.nav-menu li.active {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
}

.nav-menu li i {
    font-size: 18px;
    width: 24px;
    text-align: center;
}

.nav-menu li span {
    font-size: 14px;
    font-weight: 500;
}

/* Progress Section */
.progress-section {
    padding: 24px;
    border-top: 1px solid var(--border-color);
}

.progress-section h4 {
    font-size: 14px;
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.progress-ring {
    position: relative;
    width: 120px;
    height: 120px;
    margin: 0 auto;
}

.progress-ring svg {
    transform: rotate(-90deg);
    width: 100%;
    height: 100%;
}

.progress-bg {
    fill: none;
    stroke: #e2e8f0;
    stroke-width: 8;
}

.progress-fill {
    fill: none;
    stroke: var(--primary-color);
    stroke-width: 8;
    stroke-linecap: round;
    transition: stroke-dashoffset 0.5s ease;
}

.progress-text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
}

.progress-text span {
    display: block;
    font-size: 28px;
    font-weight: 700;
    color: var(--primary-color);
}

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

/* Main Content */
.main-content {
    flex: 1;
    margin-left: 280px;
    display: flex;
    flex-direction: column;
}

/* Header */
.header {
    background: var(--card-bg);
    padding: 16px 32px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 50;
}

.search-bar {
    display: flex;
    align-items: center;
    background: var(--bg-color);
    border-radius: var(--radius);
    padding: 10px 16px;
    width: 400px;
    border: 1px solid var(--border-color);
}

.search-bar i {
    color: var(--text-secondary);
    margin-right: 10px;
}

.search-bar input {
    border: none;
    background: none;
    outline: none;
    width: 100%;
    font-size: 14px;
    color: var(--text-primary);
}

.header-actions {
    display: flex;
    gap: 12px;
}

.btn-icon {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
    background: var(--card-bg);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    color: var(--text-secondary);
}

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

/* Sections */
.section {
    display: none;
    padding: 32px;
    flex: 1;
}

.section.active {
    display: block;
}

.page-title {
    font-size: 32px;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.page-subtitle {
    color: var(--text-secondary);
    margin-bottom: 32px;
    font-size: 16px;
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    margin-bottom: 32px;
}

.stat-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 24px;
    display: flex;
    align-items: center;
    gap: 16px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.stat-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.stat-icon {
    width: 56px;
    height: 56px;
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
}

.stat-icon.blue {
    background: #dbeafe;
    color: #2563eb;
}

.stat-icon.green {
    background: #d1fae5;
    color: #10b981;
}

.stat-icon.orange {
    background: #ffedd5;
    color: #f97316;
}

.stat-icon.purple {
    background: #ede9fe;
    color: #8b5cf6;
}

.stat-info h3 {
    font-size: 28px;
    font-weight: 700;
    color: var(--text-primary);
}

.stat-info p {
    font-size: 14px;
    color: var(--text-secondary);
}

/* Quick Actions */
.quick-actions {
    margin-bottom: 32px;
}

.quick-actions h2 {
    font-size: 20px;
    margin-bottom: 20px;
    color: var(--text-primary);
}

.action-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.action-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 28px;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    border: 2px solid transparent;
    box-shadow: var(--shadow);
}

.action-card:hover {
    border-color: var(--primary-color);
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.action-card i {
    font-size: 40px;
    color: var(--primary-color);
    margin-bottom: 16px;
}

.action-card h3 {
    font-size: 18px;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.action-card p {
    font-size: 14px;
    color: var(--text-secondary);
}

/* Recent Topics */
.recent-topics h2 {
    font-size: 20px;
    margin-bottom: 20px;
    color: var(--text-primary);
}

.topic-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.topic-tag {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    padding: 10px 20px;
    border-radius: 100px;
    font-size: 14px;
    cursor: pointer;
    transition: var(--transition);
    color: var(--text-secondary);
}

.topic-tag:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

/* Flashcards Section */
.flashcard-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}

.category-filter select {
    padding: 10px 16px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
    background: var(--card-bg);
    font-size: 14px;
    cursor: pointer;
}

.flashcard-nav {
    display: flex;
    align-items: center;
    gap: 16px;
}

#card-counter {
    font-weight: 600;
    color: var(--text-secondary);
}

.btn-secondary {
    padding: 10px 20px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
    background: var(--card-bg);
    cursor: pointer;
    font-size: 14px;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: var(--transition);
}

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

.flashcard-container {
    display: flex;
    justify-content: center;
    margin-bottom: 32px;
}

.flashcard {
    width: 700px;
    height: 450px;
    perspective: 1000px;
    cursor: pointer;
}

.flashcard-inner {
    width: 100%;
    height: 100%;
    position: relative;
    transform-style: preserve-3d;
    transition: transform 0.6s;
}

.flashcard.flipped .flashcard-inner {
    transform: rotateY(180deg);
}

.flashcard-front,
.flashcard-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: var(--radius);
    padding: 40px;
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-lg);
}

.flashcard-front {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    align-items: center;
    justify-content: center;
    text-align: center;
}

.flashcard-back {
    background: var(--card-bg);
    transform: rotateY(180deg);
    overflow-y: auto;
}

.card-category {
    background: rgba(255, 255, 255, 0.2);
    padding: 8px 16px;
    border-radius: 100px;
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 24px;
}

.flashcard-front h3 {
    font-size: 28px;
    font-weight: 600;
    line-height: 1.4;
}

.flip-hint {
    margin-top: auto;
    font-size: 14px;
    opacity: 0.8;
}

.flip-hint i {
    margin-right: 8px;
}

.flashcard-back h4 {
    color: var(--primary-color);
    margin-bottom: 16px;
    font-size: 16px;
}

.flashcard-back p {
    color: var(--text-primary);
    line-height: 1.8;
    font-size: 15px;
}

.card-actions {
    margin-top: auto;
    display: flex;
    gap: 12px;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
}

.btn-difficulty {
    flex: 1;
    padding: 12px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
    background: var(--card-bg);
    cursor: pointer;
    font-size: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: var(--transition);
}

.btn-difficulty[data-level="hard"]:hover {
    background: #fee2e2;
    color: var(--danger-color);
    border-color: var(--danger-color);
}

.btn-difficulty[data-level="medium"]:hover {
    background: #fef3c7;
    color: var(--warning-color);
    border-color: var(--warning-color);
}

.btn-difficulty[data-level="easy"]:hover {
    background: #d1fae5;
    color: var(--success-color);
    border-color: var(--success-color);
}

.flashcard-buttons {
    display: flex;
    justify-content: center;
    gap: 16px;
}

.btn-primary {
    padding: 14px 32px;
    border-radius: var(--radius-sm);
    border: none;
    background: var(--primary-color);
    color: white;
    cursor: pointer;
    font-size: 16px;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: var(--transition);
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

.btn-large {
    padding: 16px 48px;
    font-size: 18px;
}

/* Quiz Section */
.quiz-container {
    max-width: 800px;
    margin: 0 auto;
}

.quiz-intro {
    text-align: center;
    padding: 60px 40px;
    background: var(--card-bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.quiz-intro i {
    font-size: 64px;
    color: var(--primary-color);
    margin-bottom: 24px;
}

.quiz-intro h2 {
    font-size: 28px;
    margin-bottom: 12px;
}

.quiz-intro p {
    color: var(--text-secondary);
    margin-bottom: 32px;
}

.quiz-options {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-bottom: 32px;
    max-width: 400px;
    margin-left: auto;
    margin-right: auto;
}

.quiz-options label {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
}

.quiz-options label:hover {
    border-color: var(--primary-color);
}

.quiz-options input[type="radio"] {
    width: 20px;
    height: 20px;
    accent-color: var(--primary-color);
}

.quiz-options input[type="radio"]:checked + span {
    color: var(--primary-color);
    font-weight: 600;
}

.quiz-question {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 40px;
    box-shadow: var(--shadow);
}

.quiz-progress {
    margin-bottom: 32px;
}

.progress-bar {
    height: 8px;
    background: #e2e8f0;
    border-radius: 100px;
    margin-bottom: 12px;
    overflow: hidden;
}

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

#quiz-progress-text {
    font-size: 14px;
    color: var(--text-secondary);
}

.quiz-question h3 {
    font-size: 22px;
    margin-bottom: 32px;
    color: var(--text-primary);
}

.quiz-options-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.quiz-option {
    padding: 20px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 16px;
}

.quiz-option:hover {
    border-color: var(--primary-color);
    background: #f8fafc;
}

.quiz-option.selected {
    border-color: var(--primary-color);
    background: #eff6ff;
}

.quiz-option.correct {
    border-color: var(--success-color);
    background: #d1fae5;
}

.quiz-option.incorrect {
    border-color: var(--danger-color);
    background: #fee2e2;
}

.quiz-option-letter {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--bg-color);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    color: var(--text-secondary);
}

.quiz-option.selected .quiz-option-letter {
    background: var(--primary-color);
    color: white;
}

.quiz-option.correct .quiz-option-letter {
    background: var(--success-color);
    color: white;
}

.quiz-option.incorrect .quiz-option-letter {
    background: var(--danger-color);
    color: white;
}

/* Quiz Results */
.quiz-results {
    text-align: center;
    padding: 60px 40px;
    background: var(--card-bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.results-summary i {
    font-size: 64px;
    color: var(--warning-color);
    margin-bottom: 24px;
}

.results-summary h2 {
    font-size: 28px;
    margin-bottom: 24px;
}

.score-display {
    margin-bottom: 32px;
}

.score-display span {
    display: block;
    font-size: 48px;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 8px;
}

.score-display p {
    font-size: 18px;
    color: var(--text-secondary);
}

.results-actions {
    display: flex;
    justify-content: center;
    gap: 16px;
}

/* Topics Section */
.topics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 24px;
}

.topic-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 28px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    cursor: pointer;
    border: 2px solid transparent;
}

.topic-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.topic-card-header {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 16px;
}

.topic-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
}

.topic-card h3 {
    font-size: 18px;
    color: var(--text-primary);
}

.topic-card p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.6;
}

.topic-progress {
    margin-top: 20px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.topic-progress-bar {
    flex: 1;
    height: 6px;
    background: #e2e8f0;
    border-radius: 100px;
    overflow: hidden;
}

.topic-progress-fill {
    height: 100%;
    background: var(--primary-color);
    border-radius: 100px;
    transition: width 0.3s ease;
}

.topic-progress span {
    font-size: 12px;
    color: var(--text-secondary);
    font-weight: 500;
}

/* Abbreviations Section */
.abbreviations-search {
    margin-bottom: 24px;
}

.abbreviations-search input {
    width: 100%;
    padding: 14px 20px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 16px;
    outline: none;
}

.abbreviations-search input:focus {
    border-color: var(--primary-color);
}

.abbreviations-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 16px;
}

.abbreviation-item {
    background: var(--card-bg);
    border-radius: var(--radius-sm);
    padding: 20px;
    box-shadow: var(--shadow);
    border-left: 4px solid var(--primary-color);
}

.abbreviation-item h4 {
    font-size: 18px;
    color: var(--primary-color);
    margin-bottom: 8px;
}

.abbreviation-item p {
    font-size: 14px;
    color: var(--text-secondary);
}

/* Documents Section */
.documents-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(400px, 1fr));
    gap: 24px;
}

.document-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 28px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.document-card:hover {
    box-shadow: var(--shadow-lg);
}

.document-header {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 16px;
}

.document-icon {
    width: 56px;
    height: 56px;
    border-radius: var(--radius);
    background: #dbeafe;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
}

.document-card h3 {
    font-size: 18px;
    margin-bottom: 4px;
}

.document-card .doc-type {
    font-size: 12px;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.document-content {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.8;
}

.document-content ul {
    margin-top: 12px;
    margin-left: 20px;
}

.document-content li {
    margin-bottom: 8px;
}

/* Interview Section */
.interview-content {
    display: flex;
    flex-direction: column;
    gap: 32px;
}

.interview-section {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 32px;
    box-shadow: var(--shadow);
}

.interview-section h2 {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 22px;
    margin-bottom: 24px;
    color: var(--text-primary);
}

.interview-section h2 i {
    color: var(--primary-color);
}

.question-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.question-item {
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    overflow: hidden;
}

.question-header {
    padding: 20px;
    background: #f8fafc;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: var(--transition);
}

.question-header:hover {
    background: #f1f5f9;
}

.question-header h4 {
    font-size: 16px;
    font-weight: 500;
    color: var(--text-primary);
}

.question-header i {
    color: var(--text-secondary);
    transition: var(--transition);
}

.question-item.expanded .question-header i {
    transform: rotate(180deg);
}

.question-answer {
    padding: 20px;
    display: none;
    border-top: 1px solid var(--border-color);
}

.question-item.expanded .question-answer {
    display: block;
}

.question-answer p {
    color: var(--text-secondary);
    line-height: 1.8;
    font-size: 14px;
}

.tips-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.tip-card {
    background: #f8fafc;
    border-radius: var(--radius-sm);
    padding: 24px;
    text-align: center;
    transition: var(--transition);
}

.tip-card:hover {
    background: #f1f5f9;
    transform: translateY(-2px);
}

.tip-card i {
    font-size: 32px;
    color: var(--primary-color);
    margin-bottom: 16px;
}

.tip-card h3 {
    font-size: 16px;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.tip-card p {
    font-size: 14px;
    color: var(--text-secondary);
}

/* Responsive Design */
@media (max-width: 1200px) {
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .action-cards {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .sidebar {
        width: 100%;
        position: fixed;
        bottom: 0;
        height: auto;
        flex-direction: row;
        padding: 8px;
        z-index: 1000;
    }
    
    .logo, .progress-section {
        display: none;
    }
    
    .nav-menu {
        display: flex;
        justify-content: space-around;
        padding: 0;
        width: 100%;
    }
    
    .nav-menu li {
        flex-direction: column;
        padding: 8px;
        margin: 0;
    }
    
    .nav-menu li span {
        font-size: 10px;
    }
    
    .main-content {
        margin-left: 0;
        margin-bottom: 80px;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .action-cards {
        grid-template-columns: 1fr;
    }
    
    .flashcard {
        width: 100%;
        height: 400px;
    }
    
    .tips-grid {
        grid-template-columns: 1fr;
    }
}