/* ============================================
   Lesson Page Styles
   ============================================ */

.lesson-container {
    padding: 2rem 0 4rem;
    min-height: calc(100vh - 200px);
}

.lesson-layout {
    display: grid;
    grid-template-columns: 1fr 350px;
    gap: 2rem;
}

/* Main Content */
.lesson-main {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 1rem;
    padding: 2rem;
}

.lesson-header {
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.lesson-title-main {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.lesson-meta-main {
    display: flex;
    gap: 1.5rem;
}

/* Tabs */
.lesson-tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 2rem;
    border-bottom: 2px solid var(--border-color);
}

.tab-button {
    padding: 0.875rem 1.5rem;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    border-bottom: 2px solid transparent;
    margin-bottom: -2px;
}

.tab-button:hover {
    color: var(--text-primary);
    background: var(--bg-tertiary);
}

.tab-button.active {
    color: var(--accent-color);
    border-bottom-color: var(--accent-color);
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

/* Theory Content */
.theory-content {
    line-height: 1.8;
    color: var(--text-primary);
}

.theory-content h1,
.theory-content h2,
.theory-content h3 {
    margin-top: 2rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.theory-content h1 {
    font-size: 1.75rem;
}

.theory-content h2 {
    font-size: 1.5rem;
}

.theory-content h3 {
    font-size: 1.25rem;
}

.theory-content p {
    margin-bottom: 1rem;
}

.theory-content ul,
.theory-content ol {
    margin-left: 1.5rem;
    margin-bottom: 1rem;
}

.theory-content li {
    margin-bottom: 0.5rem;
}

.theory-content code {
    background: var(--bg-tertiary);
    padding: 0.2rem 0.4rem;
    border-radius: 0.25rem;
    font-family: 'Courier New', monospace;
    font-size: 0.9em;
}

.theory-content pre {
    background: var(--bg-tertiary);
    padding: 1rem;
    border-radius: 0.5rem;
    overflow-x: auto;
    margin-bottom: 1rem;
}

/* 3D Model Viewer */
.model-viewer-container {
    margin-bottom: 2rem;
}

.lesson-3d-viewer {
    width: 100%;
    height: 500px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    margin-bottom: 1rem;
}

.viewer-controls {
    display: flex;
    gap: 0.5rem;
    justify-content: center;
}

.viewer-btn {
    padding: 0.5rem 1rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    color: var(--text-primary);
    cursor: pointer;
    transition: all 0.2s;
}

.viewer-btn:hover {
    background: var(--bg-primary);
    border-color: var(--accent-color);
}

.component-info {
    padding: 1.5rem;
    background: var(--bg-tertiary);
    border-radius: 0.5rem;
}

.component-info h3 {
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.component-info p {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Video */
.video-container {
    position: relative;
    padding-bottom: 56.25%;
    height: 0;
    overflow: hidden;
    border-radius: 0.5rem;
}

.video-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

/* Quiz */
.quiz-section {
    margin-top: 3rem;
    padding: 2rem;
    background: var(--bg-tertiary);
    border-radius: 0.5rem;
}

.quiz-title {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.quiz-description {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.quiz-meta {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 2rem;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.quiz-question {
    margin-bottom: 2rem;
    padding: 1.5rem;
    background: var(--bg-secondary);
    border-radius: 0.5rem;
}

.question-text {
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.question-options {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.option-label {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem;
    background: var(--bg-tertiary);
    border: 2px solid var(--border-color);
    border-radius: 0.5rem;
    cursor: pointer;
    transition: all 0.2s;
}

.option-label:hover {
    border-color: var(--accent-color);
    background: var(--bg-primary);
}

.option-label input[type="radio"] {
    width: 20px;
    height: 20px;
    cursor: pointer;
}

.quiz-results {
    margin-top: 2rem;
    padding: 1.5rem;
    background: var(--bg-secondary);
    border-radius: 0.5rem;
}

.result-score {
    font-size: 2rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 1rem;
}

.result-score.passed {
    color: #48bb78;
}

.result-score.failed {
    color: #f56565;
}

/* Navigation */
.lesson-navigation {
    display: flex;
    justify-content: space-between;
    gap: 1rem;
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

.nav-btn {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem 1.5rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    text-decoration: none;
    color: var(--text-primary);
    transition: all 0.2s;
    max-width: 45%;
}

.nav-btn:hover {
    background: var(--bg-primary);
    border-color: var(--accent-color);
    transform: translateX(0);
}

.nav-btn.prev:hover {
    transform: translateX(-5px);
}

.nav-btn.next:hover {
    transform: translateX(5px);
}

.nav-icon {
    font-size: 1.25rem;
}

.nav-text {
    font-weight: 500;
}

/* Sidebar */
.lesson-sidebar {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.sidebar-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 1rem;
    padding: 1.5rem;
}

.sidebar-title {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.progress-status {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem;
    background: var(--bg-tertiary);
    border-radius: 0.5rem;
    margin-bottom: 1rem;
}

.progress-status.completed {
    background: rgba(72, 187, 120, 0.1);
    color: #48bb78;
}

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

.btn-block {
    width: 100%;
    justify-content: center;
}

.sidebar-lessons {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.sidebar-lesson {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    text-decoration: none;
    color: var(--text-secondary);
    transition: all 0.2s;
}

.sidebar-lesson:hover {
    background: var(--bg-primary);
    border-color: var(--accent-color);
    color: var(--text-primary);
}

.sidebar-lesson.active {
    background: var(--accent-color);
    border-color: var(--accent-color);
    color: white;
}

.lesson-num {
    flex-shrink: 0;
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-secondary);
    border-radius: 50%;
    font-size: 0.875rem;
    font-weight: 600;
}

.sidebar-lesson.active .lesson-num {
    background: rgba(255, 255, 255, 0.2);
    color: white;
}

.lesson-name {
    font-size: 0.875rem;
    line-height: 1.4;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .lesson-layout {
        grid-template-columns: 1fr;
    }

    .lesson-sidebar {
        order: -1;
    }
}

@media (max-width: 768px) {
    .lesson-main {
        padding: 1.5rem;
    }

    .lesson-title-main {
        font-size: 1.5rem;
    }

    .lesson-tabs {
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
    }

    .tab-button {
        white-space: nowrap;
    }

    .lesson-3d-viewer {
        height: 300px;
    }

    .lesson-navigation {
        flex-direction: column;
    }

    .nav-btn {
        max-width: 100%;
    }
}

/* Notes Styles */
.note-textarea {
    width: 100%;
    min-height: 150px;
    padding: 0.75rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.875rem;
    line-height: 1.5;
    resize: vertical;
    transition: border-color 0.2s;
}

.note-textarea:focus {
    outline: none;
    border-color: var(--accent-color);
}

.note-textarea::placeholder {
    color: var(--text-secondary);
}

.save-status {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.save-status.saving {
    color: var(--accent-color);
}

.save-status.saved {
    color: #48bb78;
}

.save-status.error {
    color: #f56565;
}

.btn-sm {
    padding: 0.5rem 0.75rem;
    font-size: 0.875rem;
}

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

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

.btn-secondary.active {
    background: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
}