/* Kong API Gateway & Konnect Learning Platform - Design System & Styles */
:root {
    --bg-primary: #0a0f1d;
    --bg-secondary: #111827;
    --bg-card: #1f2937;
    --bg-card-hover: #374151;
    --bg-input: #111827;

    --accent-primary: #00b4d8;
    --accent-hover: #0096c7;
    --accent-glow: rgba(0, 180, 216, 0.25);
    
    --kong-purple: #7209b7;
    --kong-blue: #4361ee;
    --kong-cyan: #4cc9f0;
    
    --text-primary: #f9fafb;
    --text-secondary: #9ca3af;
    --text-muted: #6b7280;

    --border-color: #374151;
    --border-highlight: #4b5563;

    --success-color: #10b981;
    --success-bg: rgba(16, 185, 129, 0.15);
    --warning-color: #f59e0b;
    --warning-bg: rgba(245, 158, 11, 0.15);
    --danger-color: #ef4444;
    --danger-bg: rgba(239, 68, 68, 0.15);

    --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;

    --sidebar-width: 340px;
    --header-height: 70px;
}

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

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: var(--font-sans);
    line-height: 1.6;
    overflow-x: hidden;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}
::-webkit-scrollbar-track {
    background: var(--bg-primary);
}
::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--accent-primary);
}

/* Header Styles */
.app-header {
    height: var(--header-height);
    background: rgba(17, 24, 39, 0.85);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 24px;
    position: sticky;
    top: 0;
    z-index: 100;
}

.brand {
    display: flex;
    align-items: center;
    gap: 12px;
}

.brand-icon {
    width: 42px;
    height: 42px;
    background: linear-gradient(135deg, var(--kong-purple), var(--accent-primary));
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 0 15px var(--accent-glow);
}

.brand-icon svg {
    width: 24px;
    height: 24px;
    fill: #ffffff;
}

.brand-text h1 {
    font-size: 1.15rem;
    font-weight: 800;
    background: linear-gradient(90deg, #ffffff, var(--kong-cyan));
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.02em;
}

.brand-text span {
    font-size: 0.75rem;
    color: var(--text-secondary);
    display: block;
    font-weight: 500;
}

.header-center {
    flex: 1;
    max-width: 500px;
    margin: 0 24px;
}

.search-box {
    position: relative;
    width: 100%;
}

.search-box input {
    width: 100%;
    background-color: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 10px 16px 10px 40px;
    color: var(--text-primary);
    font-size: 0.9rem;
    outline: none;
    transition: all 0.2s ease;
}

.search-box input:focus {
    border-color: var(--accent-primary);
    box-shadow: 0 0 10px var(--accent-glow);
}

.search-icon {
    position: absolute;
    left: 12px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
    font-size: 0.9rem;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 16px;
}

.progress-widget {
    display: flex;
    align-items: center;
    gap: 12px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    padding: 8px 14px;
    border-radius: 8px;
}

.progress-bar-bg {
    width: 120px;
    height: 8px;
    background: var(--bg-card);
    border-radius: 4px;
    overflow: hidden;
}

.progress-bar-fill {
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, var(--kong-blue), var(--accent-primary));
    transition: width 0.3s ease;
}

.progress-text {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--kong-cyan);
    white-space: nowrap;
}

/* App Container Layout */
.app-container {
    display: flex;
    height: calc(100vh - var(--header-height));
    overflow: hidden;
}

/* Sidebar Styles */
.app-sidebar {
    width: var(--sidebar-width);
    background-color: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    flex-shrink: 0;
}

.sidebar-header {
    padding: 16px 20px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-weight: 700;
    font-size: 0.95rem;
}

.category-filter-container {
    padding: 12px 16px;
    display: flex;
    gap: 6px;
    overflow-x: auto;
    border-bottom: 1px solid var(--border-color);
}

.category-pill {
    padding: 4px 10px;
    font-size: 0.72rem;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    color: var(--text-secondary);
    cursor: pointer;
    white-space: nowrap;
    transition: all 0.2s ease;
}

.category-pill:hover, .category-pill.active {
    background: var(--accent-primary);
    color: #ffffff;
    border-color: var(--accent-primary);
}

.sidebar-exam-btn {
    margin: 12px 16px 4px 16px;
    padding: 10px 14px;
    background: linear-gradient(135deg, var(--kong-purple), var(--kong-blue));
    color: #ffffff;
    border: none;
    border-radius: 8px;
    font-weight: 700;
    font-size: 0.85rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.sidebar-exam-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(114, 9, 183, 0.4);
}

#chapterListContainer {
    flex: 1;
    overflow-y: auto;
    padding: 8px 12px;
}

.chapter-item {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    padding: 10px 12px;
    border-radius: 8px;
    margin-bottom: 4px;
    cursor: pointer;
    border: 1px solid transparent;
    transition: all 0.2s ease;
}

.chapter-item:hover {
    background-color: var(--bg-card);
    border-color: var(--border-color);
}

.chapter-item.active {
    background: rgba(0, 180, 216, 0.12);
    border-color: var(--accent-primary);
}

.chapter-checkbox {
    margin-top: 3px;
    width: 16px;
    height: 16px;
    accent-color: var(--accent-primary);
    cursor: pointer;
}

.chapter-info {
    flex: 1;
    min-width: 0;
}

.chapter-title {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.chapter-meta-sm {
    font-size: 0.72rem;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: 8px;
    margin-top: 2px;
}

/* Main Content Area */
.main-content {
    flex: 1;
    overflow-y: auto;
    padding: 28px 36px;
    background-color: var(--bg-primary);
}

.chapter-header {
    background: linear-gradient(135deg, rgba(31, 41, 55, 0.8), rgba(17, 24, 39, 0.9));
    border: 1px solid var(--border-color);
    border-radius: 14px;
    padding: 24px 28px;
    margin-bottom: 24px;
    position: relative;
}

.chapter-meta {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 10px;
}

.badge {
    padding: 4px 10px;
    border-radius: 6px;
    font-size: 0.72rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--kong-cyan);
}

.badge-blue { background: rgba(67, 97, 238, 0.2); color: #4361ee; border-color: rgba(67, 97, 238, 0.4); }
.badge-purple { background: rgba(114, 9, 183, 0.2); color: #b5179e; border-color: rgba(114, 9, 183, 0.4); }
.badge-cyan { background: rgba(0, 180, 216, 0.2); color: #00b4d8; border-color: rgba(0, 180, 216, 0.4); }
.badge-green { background: rgba(16, 185, 129, 0.2); color: #10b981; border-color: rgba(16, 185, 129, 0.4); }

.video-timestamp {
    font-size: 0.78rem;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 4px;
}

.video-timestamp strong {
    color: var(--text-primary);
    font-family: var(--font-mono);
}

.chapter-header h2 {
    font-size: 1.6rem;
    font-weight: 800;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.chapter-desc {
    color: var(--text-secondary);
    font-size: 0.95rem;
    max-width: 900px;
}

.chapter-actions {
    position: absolute;
    top: 24px;
    right: 28px;
    display: flex;
    gap: 10px;
}

/* Tabs Navigation */
.tabs-nav {
    display: flex;
    gap: 8px;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 24px;
}

.tab-btn {
    padding: 12px 20px;
    background: transparent;
    border: none;
    border-bottom: 2px solid transparent;
    color: var(--text-secondary);
    font-weight: 600;
    font-size: 0.9rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: all 0.2s ease;
}

.tab-btn:hover {
    color: var(--text-primary);
}

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

/* Tab Panels */
.tab-panel {
    display: none;
    animation: fadeIn 0.25s ease;
}

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

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(6px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Article / Teori Content Styling */
.article-content {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 32px;
}

.article-section {
    margin-bottom: 32px;
}

.article-section h3 {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--kong-cyan);
    margin-bottom: 14px;
    display: flex;
    align-items: center;
    gap: 10px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    padding-bottom: 8px;
}

.article-section p {
    color: var(--text-primary);
    margin-bottom: 14px;
    font-size: 0.98rem;
    line-height: 1.7;
}

.article-section ul, .article-section ol {
    margin-left: 20px;
    margin-bottom: 16px;
    color: var(--text-secondary);
}

.article-section li {
    margin-bottom: 8px;
    line-height: 1.6;
}

.article-section strong {
    color: var(--text-primary);
}

/* Callout Cards */
.callout-box {
    background: var(--bg-card);
    border-left: 4px solid var(--accent-primary);
    padding: 16px 20px;
    border-radius: 0 8px 8px 0;
    margin: 20px 0;
    font-size: 0.92rem;
}

.callout-box.info { border-left-color: var(--accent-primary); background: rgba(0, 180, 216, 0.08); }
.callout-box.tip { border-left-color: var(--success-color); background: var(--success-bg); }
.callout-box.warning { border-left-color: var(--warning-color); background: var(--warning-bg); }

/* Code Blocks */
.code-wrapper {
    background: #0d1117;
    border: 1px solid var(--border-color);
    border-radius: 10px;
    overflow: hidden;
    margin: 20px 0;
}

.code-header {
    background: #161b22;
    padding: 8px 16px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid var(--border-color);
    font-size: 0.8rem;
    color: var(--text-secondary);
    font-family: var(--font-mono);
}

.copy-btn {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 4px 10px;
    border-radius: 4px;
    font-size: 0.75rem;
    cursor: pointer;
    transition: all 0.2s ease;
}

.copy-btn:hover {
    background: var(--accent-primary);
    color: #ffffff;
    border-color: var(--accent-primary);
}

pre code {
    display: block;
    padding: 16px 20px;
    font-family: var(--font-mono);
    font-size: 0.88rem;
    color: #e6edf3;
    overflow-x: auto;
    line-height: 1.5;
}

/* Video Tab Player */
.video-player-container {
    background: #000;
    border-radius: 12px;
    overflow: hidden;
    position: relative;
    padding-top: 56.25%; /* 16:9 Aspect Ratio */
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
    margin-bottom: 24px;
}

.video-player-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: none;
}

.video-meta-box {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 20px;
}

/* Interactive Playground Tab */
.playground-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.playground-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 20px;
    display: flex;
    flex-direction: column;
}

.playground-title {
    font-size: 1rem;
    font-weight: 700;
    color: var(--kong-cyan);
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.editor-textarea {
    width: 100%;
    height: 260px;
    background: #0d1117;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 14px;
    color: #e6edf3;
    font-family: var(--font-mono);
    font-size: 0.88rem;
    resize: none;
    outline: none;
}

.editor-textarea:focus {
    border-color: var(--accent-primary);
}

.terminal-output {
    background: #090d16;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 14px;
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: #38bdf8;
    height: 260px;
    overflow-y: auto;
    white-space: pre-wrap;
}

.btn {
    padding: 8px 16px;
    border-radius: 6px;
    font-weight: 600;
    font-size: 0.85rem;
    cursor: pointer;
    border: none;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.btn-primary {
    background: var(--accent-primary);
    color: #ffffff;
}

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

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

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

/* Quiz Styling */
.quiz-container {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 28px;
}

.quiz-question-box {
    margin-bottom: 24px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--border-color);
}

.quiz-question-title {
    font-size: 1.05rem;
    font-weight: 700;
    margin-bottom: 14px;
    color: var(--text-primary);
}

.quiz-options {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.quiz-option-item {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 12px 16px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 12px;
}

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

.quiz-option-item.selected {
    border-color: var(--accent-primary);
    background: rgba(0, 180, 216, 0.15);
}

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

.quiz-option-item.wrong {
    border-color: var(--danger-color);
    background: var(--danger-bg);
}

.quiz-explanation {
    margin-top: 12px;
    padding: 12px 16px;
    border-radius: 6px;
    font-size: 0.85rem;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    display: none;
}

/* Note Taking Tab */
.notes-container {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 24px;
}

.notes-textarea {
    width: 100%;
    height: 300px;
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 16px;
    color: var(--text-primary);
    font-family: var(--font-sans);
    font-size: 0.95rem;
    outline: none;
    resize: vertical;
    margin-bottom: 16px;
}

/* Footer Nav Control */
.footer-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 32px;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
}

/* Modal Overlay for Final Exam */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.85);
    backdrop-filter: blur(8px);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 999;
}

.modal-overlay.active {
    display: flex;
}

.modal-content {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    width: 90%;
    max-width: 800px;
    max-height: 90vh;
    overflow-y: auto;
    padding: 32px;
    position: relative;
    box-shadow: 0 20px 50px rgba(0,0,0,0.7);
}

.modal-close {
    position: absolute;
    top: 20px;
    right: 20px;
    background: transparent;
    border: none;
    color: var(--text-muted);
    font-size: 1.4rem;
    cursor: pointer;
}

.modal-close:hover {
    color: var(--text-primary);
}

/* Certificate Generator Styling */
.certificate-box {
    background: linear-gradient(135deg, #0b132b, #1c2541);
    border: 4px double var(--accent-primary);
    border-radius: 12px;
    padding: 36px;
    text-align: center;
    margin-top: 24px;
}

.certificate-box h2 {
    font-size: 1.8rem;
    color: var(--kong-cyan);
    margin-bottom: 8px;
}

.certificate-box p {
    color: var(--text-secondary);
    font-size: 1rem;
}

.certificate-name {
    font-size: 1.6rem;
    font-weight: 800;
    color: #ffffff;
    margin: 16px 0;
    border-bottom: 2px solid var(--accent-primary);
    display: inline-block;
    padding-bottom: 4px;
}