/* ==========================================================================
   Golang Dasar Interactive Technical Tutorial - Stylesheet
   Design Theme: Go Slate Dark & Cyan Modern Aesthetics
   ========================================================================== */

:root {
    --bg-dark: #f7f3eb;
    --bg-card: #fffdf8;
    --bg-card-hover: #edf4ee;
    --bg-input: #f0f5ef;
    --border-color: #d2dfd4;
    --border-highlight: #087e7a;
    
    --text-main: #173e40;
    --text-muted: #5f7472;
    --text-dim: #7b908d;
    
    --go-blue: #087e7a;
    --go-blue-light: #32aaa0;
    --go-blue-dark: #0b5858;
    --go-blue-glow: rgba(8, 126, 122, 0.18);
    
    --accent-green: #5f953c;
    --accent-amber: #b87813;
    --accent-red: #c64c39;
    --accent-purple: #6954a7;

    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', Consolas, Monaco, monospace;
    
    --sidebar-width: 320px;
    --header-height: 70px;
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    background-color: var(--bg-dark);
    color: var(--text-main);
    font-family: var(--font-sans);
    font-size: 15px;
    line-height: 1.6;
    overflow-x: hidden;
    height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}
::-webkit-scrollbar-track {
    background: var(--bg-dark);
}
::-webkit-scrollbar-thumb {
    background: #232f48;
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--go-blue-dark);
}

/* Header */
.app-header {
    height: var(--header-height);
    background: rgba(21, 28, 44, 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;
    text-decoration: none;
}

.brand-icon {
    width: 38px;
    height: 38px;
    background: linear-gradient(135deg, var(--go-blue), var(--go-blue-dark));
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 0 15px var(--go-blue-glow);
}

.brand-icon svg {
    width: 22px;
    height: 22px;
    fill: #ffffff;
}

.brand-text h1 {
    font-size: 1.15rem;
    font-weight: 700;
    color: #ffffff;
    letter-spacing: -0.02em;
}

.brand-text span {
    font-size: 0.75rem;
    color: var(--go-blue);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.header-center {
    flex: 1;
    max-width: 480px;
    margin: 0 32px;
}

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

.search-box input {
    width: 100%;
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    padding: 9px 16px 9px 40px;
    border-radius: var(--radius-md);
    color: var(--text-main);
    font-size: 0.9rem;
    outline: none;
    transition: var(--transition);
}

.search-box input:focus {
    border-color: var(--go-blue);
    box-shadow: 0 0 0 3px var(--go-blue-glow);
}

.search-icon {
    position: absolute;
    left: 14px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-dim);
    pointer-events: none;
}

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

.progress-widget {
    display: flex;
    align-items: center;
    gap: 12px;
    background: var(--bg-input);
    padding: 6px 14px;
    border-radius: 30px;
    border: 1px solid var(--border-color);
}

.progress-bar-bg {
    width: 100px;
    height: 8px;
    background: rgba(255,255,255,0.08);
    border-radius: 4px;
    overflow: hidden;
}

.progress-bar-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--go-blue), var(--accent-green));
    width: 0%;
    transition: width 0.4s ease;
}

.progress-text {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-muted);
}

/* Layout */
.app-container {
    display: flex;
    flex: 1;
    overflow: hidden;
}

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

.sidebar-header {
    padding: 16px 20px;
    border-bottom: 1px solid var(--border-color);
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--text-dim);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.section-title {
    padding: 12px 20px 6px;
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--go-blue);
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.chapter-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 20px;
    cursor: pointer;
    border-left: 3px solid transparent;
    transition: var(--transition);
    text-decoration: none;
    color: var(--text-muted);
}

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

.chapter-item.active {
    background: rgba(0, 173, 216, 0.1);
    border-left-color: var(--go-blue);
    color: #ffffff;
    font-weight: 600;
}

.chapter-info {
    display: flex;
    align-items: center;
    gap: 10px;
    overflow: hidden;
}

.chapter-num {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    background: rgba(255,255,255,0.06);
    padding: 2px 6px;
    border-radius: 4px;
    min-width: 24px;
    text-align: center;
}

.chapter-title-text {
    font-size: 0.88rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.chapter-status {
    width: 16px;
    height: 16px;
    border-radius: 50%;
    border: 2px solid var(--text-dim);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.chapter-item.completed .chapter-status {
    background: var(--accent-green);
    border-color: var(--accent-green);
}

.chapter-item.completed .chapter-status::after {
    content: "✓";
    color: #ffffff;
    font-size: 10px;
    font-weight: bold;
}

/* Main Content */
.main-content {
    flex: 1;
    overflow-y: auto;
    padding: 32px 40px;
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.chapter-header {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 28px;
    position: relative;
    overflow: hidden;
}

.chapter-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 6px;
    height: 100%;
    background: linear-gradient(180deg, var(--go-blue), var(--accent-purple));
}

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

.badge {
    background: rgba(0, 173, 216, 0.15);
    color: var(--go-blue);
    border: 1px solid rgba(0, 173, 216, 0.3);
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
}

.video-timestamp {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--accent-amber);
    background: rgba(245, 158, 11, 0.1);
    padding: 4px 10px;
    border-radius: 20px;
    border: 1px solid rgba(245, 158, 11, 0.2);
    display: flex;
    align-items: center;
    gap: 6px;
}

.chapter-header h2 {
    font-size: 1.8rem;
    font-weight: 800;
    color: #ffffff;
    margin-bottom: 8px;
    letter-spacing: -0.02em;
}

.chapter-desc {
    color: var(--text-muted);
    font-size: 1rem;
    max-width: 800px;
}

/* Tabs Navigation */
.tabs-nav {
    display: flex;
    gap: 8px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 2px;
}

.tab-btn {
    background: transparent;
    border: none;
    color: var(--text-muted);
    padding: 10px 20px;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    border-radius: var(--radius-md) var(--radius-md) 0 0;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 8px;
    position: relative;
}

.tab-btn:hover {
    color: var(--text-main);
    background: rgba(255,255,255,0.03);
}

.tab-btn.active {
    color: var(--go-blue);
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-bottom: 1px solid var(--bg-card);
    margin-bottom: -1px;
}

/* Tab Panels */
.tab-content {
    display: none;
}
.tab-content.active {
    display: block;
}

/* Theory Section */
.theory-container {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 32px;
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.theory-section h3 {
    font-size: 1.3rem;
    font-weight: 700;
    color: #ffffff;
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.theory-section h3::before {
    content: '';
    display: inline-block;
    width: 8px;
    height: 18px;
    background: var(--go-blue);
    border-radius: 4px;
}

.theory-section p {
    color: var(--text-muted);
    line-height: 1.7;
    margin-bottom: 16px;
}

.theory-section ul, .theory-section ol {
    margin-left: 24px;
    margin-bottom: 16px;
    color: var(--text-muted);
}

.theory-section li {
    margin-bottom: 8px;
}

/* Code Snippet Box in Theory */
.code-box {
    background: #0d121f;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    overflow: hidden;
    margin: 16px 0;
}

.code-box-header {
    background: #141b2a;
    padding: 8px 16px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid var(--border-color);
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--text-dim);
}

.code-box pre {
    padding: 16px;
    overflow-x: auto;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: #e2e8f0;
    line-height: 1.5;
}

/* Callout Boxes */
.callout {
    padding: 16px 20px;
    border-radius: var(--radius-md);
    border-left: 4px solid;
    margin: 16px 0;
}

.callout-info {
    background: rgba(0, 173, 216, 0.08);
    border-color: var(--go-blue);
    color: #dbeafe;
}

.callout-warning {
    background: rgba(245, 158, 11, 0.08);
    border-color: var(--accent-amber);
    color: #fef3c7;
}

.callout-tip {
    background: rgba(16, 185, 129, 0.08);
    border-color: var(--accent-green);
    color: #d1fae5;
}

.callout-title {
    font-weight: 700;
    margin-bottom: 6px;
    display: flex;
    align-items: center;
    gap: 8px;
}

/* Visual Tables */
.tech-table {
    width: 100%;
    border-collapse: collapse;
    margin: 16px 0;
    background: #111726;
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 1px solid var(--border-color);
}

.tech-table th, .tech-table td {
    padding: 12px 18px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.tech-table th {
    background: #182236;
    color: var(--go-blue);
    font-weight: 700;
    font-size: 0.85rem;
    text-transform: uppercase;
}

.tech-table td {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.tech-table tr:last-child td {
    border-bottom: none;
}

.tech-table code {
    background: rgba(0, 173, 216, 0.1);
    color: var(--go-blue-light);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: var(--font-mono);
}

/* Live Code Playground */
.playground-container {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.playground-toolbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 12px 20px;
}

.engine-selector {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.engine-select {
    background: var(--bg-input);
    color: var(--text-main);
    border: 1px solid var(--border-color);
    padding: 6px 12px;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    outline: none;
    cursor: pointer;
}

.btn-group {
    display: flex;
    gap: 10px;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 18px;
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    border: 1px solid transparent;
    transition: var(--transition);
}

.btn-primary {
    background: linear-gradient(135deg, var(--go-blue), var(--go-blue-dark));
    color: #ffffff;
    box-shadow: 0 4px 12px var(--go-blue-glow);
}
.btn-primary:hover {
    filter: brightness(1.15);
    transform: translateY(-1px);
}

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

.editor-wrapper {
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    overflow: hidden;
    background: #0d1117;
}

.CodeMirror {
    height: 380px !important;
    font-family: var(--font-mono) !important;
    font-size: 0.92rem !important;
    line-height: 1.6 !important;
}

.console-container {
    background: #090d16;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.console-header {
    background: #121927;
    padding: 10px 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid var(--border-color);
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--text-dim);
    text-transform: uppercase;
}

.console-status {
    font-size: 0.8rem;
    color: var(--accent-green);
    display: flex;
    align-items: center;
    gap: 6px;
}

.console-output {
    padding: 20px;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: #38edf8;
    white-space: pre-wrap;
    min-height: 120px;
    max-height: 250px;
    overflow-y: auto;
}

.console-output.error {
    color: var(--accent-red);
}

/* Quiz Section */
.quiz-container {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 32px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.quiz-question {
    font-size: 1.1rem;
    font-weight: 700;
    color: #ffffff;
}

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

.quiz-option {
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    padding: 14px 20px;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--text-muted);
}

.quiz-option:hover {
    border-color: var(--go-blue);
    color: var(--text-main);
    background: var(--bg-card-hover);
}

.quiz-option.selected {
    border-color: var(--go-blue);
    background: rgba(0, 173, 216, 0.1);
    color: #ffffff;
}

.quiz-option.correct {
    border-color: var(--accent-green);
    background: rgba(16, 185, 129, 0.15);
    color: #ffffff;
}

.quiz-option.incorrect {
    border-color: var(--accent-red);
    background: rgba(239, 68, 68, 0.15);
    color: #ffffff;
}

.quiz-option-radio {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    border: 2px solid var(--text-dim);
    flex-shrink: 0;
}

.quiz-option.selected .quiz-option-radio {
    border-color: var(--go-blue);
    background: var(--go-blue);
}

.quiz-feedback {
    margin-top: 10px;
    padding: 16px;
    border-radius: var(--radius-md);
    display: none;
    font-size: 0.95rem;
}

/* Bottom Navigation */
.chapter-nav-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 24px;
    padding-top: 24px;
    border-top: 1px solid var(--border-color);
}

/* Spinner */
.spinner {
    display: inline-block;
    width: 14px;
    height: 14px;
    border: 2px solid rgba(255,255,255,0.3);
    border-radius: 50%;
    border-top-color: #ffffff;
    animation: spin 0.8s ease-in-out infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Responsive adjustments */
@media (max-width: 992px) {
    .app-sidebar {
        position: fixed;
        left: -320px;
        top: var(--header-height);
        bottom: 0;
        z-index: 90;
        transition: var(--transition);
    }
    .app-sidebar.open {
        left: 0;
    }
    .main-content {
        padding: 20px;
    }
    .header-center {
        margin: 0 12px;
    }
}

/* ══════════════════════════════════════════════════
   HARD QUIZ TAB STYLES
   ══════════════════════════════════════════════════ */

.hard-quiz-container {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 32px;
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.hard-quiz-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border-color);
}

.hard-quiz-header h3 {
    font-size: 1.3rem;
    font-weight: 800;
    color: #fff;
    display: flex;
    align-items: center;
    gap: 10px;
}

.hard-quiz-badge {
    background: linear-gradient(135deg, #f59e0b, #ef4444);
    color: #fff;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.hard-quiz-score-display {
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 8px 20px;
    text-align: center;
    min-width: 120px;
}

.hard-quiz-score-display .score-num {
    font-size: 1.6rem;
    font-weight: 800;
    color: var(--go-blue);
    line-height: 1;
}

.hard-quiz-score-display .score-label {
    font-size: 0.75rem;
    color: var(--text-dim);
    margin-top: 2px;
}

.hard-quiz-progress-bar {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.hard-quiz-progress-track {
    flex: 1;
    height: 6px;
    background: rgba(255,255,255,0.08);
    border-radius: 3px;
    overflow: hidden;
}

.hard-quiz-progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--accent-amber), var(--accent-red));
    border-radius: 3px;
    transition: width 0.4s ease;
    width: 0%;
}

.hq-question-block {
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 20px;
    transition: var(--transition);
}

.hq-question-block.answered {
    border-color: rgba(255,255,255,0.15);
}

.hq-question-num {
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--accent-amber);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 8px;
}

.hq-question-text {
    font-size: 1rem;
    font-weight: 700;
    color: #fff;
    margin-bottom: 16px;
    line-height: 1.6;
}

.hq-options {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
}

@media (max-width: 768px) {
    .hq-options { grid-template-columns: 1fr; }
}

.hq-option {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 10px 14px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: flex-start;
    gap: 10px;
    color: var(--text-muted);
    font-size: 0.88rem;
    text-align: left;
}

.hq-option:hover:not(.hq-locked) {
    border-color: var(--accent-amber);
    color: var(--text-main);
    background: rgba(245, 158, 11, 0.06);
}

.hq-option.hq-correct {
    border-color: var(--accent-green);
    background: rgba(16, 185, 129, 0.12);
    color: #fff;
}

.hq-option.hq-wrong {
    border-color: var(--accent-red);
    background: rgba(239, 68, 68, 0.1);
    color: #fff;
}

.hq-option.hq-locked {
    cursor: default;
    opacity: 0.7;
}

.hq-option-letter {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 700;
    background: rgba(255,255,255,0.08);
    padding: 2px 7px;
    border-radius: 4px;
    min-width: 22px;
    text-align: center;
    flex-shrink: 0;
}

.hq-explanation {
    margin-top: 12px;
    padding: 12px 16px;
    border-radius: var(--radius-sm);
    font-size: 0.88rem;
    line-height: 1.6;
    display: none;
}

.hq-explanation.show { display: block; }

.hq-explanation.correct-exp {
    background: rgba(16, 185, 129, 0.08);
    border-left: 3px solid var(--accent-green);
    color: #d1fae5;
}

.hq-explanation.wrong-exp {
    background: rgba(239, 68, 68, 0.08);
    border-left: 3px solid var(--accent-red);
    color: #fee2e2;
}

.hard-quiz-result-banner {
    background: linear-gradient(135deg, rgba(0,173,216,0.12), rgba(139,92,246,0.12));
    border: 1px solid rgba(0,173,216,0.3);
    border-radius: var(--radius-md);
    padding: 20px;
    text-align: center;
    display: none;
}

.hard-quiz-result-banner.show { display: block; }
.hard-quiz-result-banner .result-title { font-size: 1.3rem; font-weight: 800; color: #fff; margin-bottom: 4px; }
.hard-quiz-result-banner .result-score { font-size: 2.5rem; font-weight: 900; color: var(--go-blue); }
.hard-quiz-result-banner .result-grade { font-size: 0.9rem; color: var(--text-muted); margin-top: 4px; }

.btn-restart-hq {
    background: linear-gradient(135deg, var(--accent-amber), #d97706);
    color: #fff;
    border: none;
    padding: 10px 24px;
    border-radius: var(--radius-md);
    font-weight: 700;
    cursor: pointer;
    margin-top: 12px;
    transition: var(--transition);
}
.btn-restart-hq:hover { filter: brightness(1.15); transform: translateY(-1px); }

/* ══════════════════════════════════════════════════
   FINAL EXAM MODAL
   ══════════════════════════════════════════════════ */

.final-exam-overlay {
    position: fixed;
    inset: 0;
    background: rgba(7, 11, 20, 0.96);
    backdrop-filter: blur(8px);
    z-index: 1000;
    display: none;
    align-items: flex-start;
    justify-content: center;
    overflow-y: auto;
    padding: 40px 20px;
}

.final-exam-overlay.open {
    display: flex;
}

.final-exam-modal {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    width: 100%;
    max-width: 840px;
    display: flex;
    flex-direction: column;
    gap: 0;
    overflow: hidden;
}

.final-exam-modal-header {
    background: linear-gradient(135deg, #0c1526, #131e35);
    border-bottom: 1px solid var(--border-color);
    padding: 28px 36px;
    position: relative;
    overflow: hidden;
}

.final-exam-modal-header::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--go-blue), var(--accent-purple), var(--accent-amber));
}

.final-exam-modal-header h2 {
    font-size: 1.6rem;
    font-weight: 900;
    color: #fff;
    letter-spacing: -0.02em;
    margin-bottom: 6px;
}

.final-exam-modal-header p {
    color: var(--text-muted);
    font-size: 0.95rem;
}

.exam-meta-row {
    display: flex;
    gap: 16px;
    margin-top: 16px;
    flex-wrap: wrap;
}

.exam-meta-item {
    display: flex;
    align-items: center;
    gap: 8px;
    background: rgba(255,255,255,0.06);
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 0.82rem;
    color: var(--text-muted);
    font-weight: 600;
}

.exam-timer {
    font-family: var(--font-mono);
    font-size: 1.4rem;
    font-weight: 800;
    color: var(--accent-amber);
    background: rgba(245,158,11,0.1);
    border: 1px solid rgba(245,158,11,0.25);
    padding: 4px 16px;
    border-radius: 8px;
    letter-spacing: 0.05em;
}

.exam-timer.danger {
    color: var(--accent-red);
    background: rgba(239,68,68,0.1);
    border-color: rgba(239,68,68,0.3);
    animation: pulse-danger 1s infinite;
}

@keyframes pulse-danger {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.7; }
}

.final-exam-body {
    padding: 28px 36px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.exam-progress-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 0.85rem;
    color: var(--text-muted);
    font-weight: 600;
}

.exam-prog-track {
    flex: 1;
    height: 6px;
    background: rgba(255,255,255,0.06);
    border-radius: 3px;
    overflow: hidden;
    margin: 0 12px;
}

.exam-prog-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--go-blue), var(--accent-purple));
    border-radius: 3px;
    transition: width 0.3s ease;
    width: 0%;
}

.exam-question-block {
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 20px 24px;
}

.exam-question-label {
    font-size: 0.72rem;
    font-weight: 700;
    color: var(--go-blue);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 10px;
}

.exam-question-text {
    font-size: 1rem;
    font-weight: 700;
    color: #fff;
    line-height: 1.6;
    margin-bottom: 16px;
}

.exam-options-grid {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.exam-option {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 12px 16px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--text-muted);
    font-size: 0.9rem;
    transition: var(--transition);
}

.exam-option:hover:not(.exam-locked) {
    border-color: var(--go-blue);
    color: var(--text-main);
    background: rgba(0,173,216,0.06);
}

.exam-option.exam-selected {
    border-color: var(--go-blue);
    background: rgba(0,173,216,0.1);
    color: #fff;
}

.exam-option.exam-correct {
    border-color: var(--accent-green);
    background: rgba(16,185,129,0.12);
    color: #fff;
}

.exam-option.exam-wrong {
    border-color: var(--accent-red);
    background: rgba(239,68,68,0.1);
    color: #fff;
}

.exam-option.exam-locked { cursor: default; }

.exam-opt-letter {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    font-weight: 800;
    background: rgba(255,255,255,0.08);
    width: 26px;
    height: 26px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 6px;
    flex-shrink: 0;
}

.exam-nav-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 4px;
}

.exam-question-dots {
    display: flex;
    gap: 5px;
    flex-wrap: wrap;
    max-width: 400px;
}

.exam-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: rgba(255,255,255,0.1);
    border: 1px solid var(--border-color);
    cursor: pointer;
    transition: var(--transition);
}

.exam-dot.answered { background: var(--go-blue); border-color: var(--go-blue); }
.exam-dot.current { background: var(--accent-amber); border-color: var(--accent-amber); transform: scale(1.3); }

.final-exam-footer {
    border-top: 1px solid var(--border-color);
    padding: 20px 36px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: rgba(255,255,255,0.02);
}

.btn-submit-exam {
    background: linear-gradient(135deg, var(--accent-green), #059669);
    color: #fff;
    border: none;
    padding: 12px 28px;
    border-radius: var(--radius-md);
    font-weight: 700;
    font-size: 0.95rem;
    cursor: pointer;
    transition: var(--transition);
}
.btn-submit-exam:hover { filter: brightness(1.12); transform: translateY(-1px); }
.btn-submit-exam:disabled { opacity: 0.4; cursor: not-allowed; transform: none; }

.btn-close-exam {
    background: var(--bg-input);
    color: var(--text-muted);
    border: 1px solid var(--border-color);
    padding: 10px 20px;
    border-radius: var(--radius-md);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}
.btn-close-exam:hover { background: var(--bg-card-hover); color: var(--text-main); }

/* Exam Result Screen */
.exam-result-screen {
    display: none;
    flex-direction: column;
    align-items: center;
    text-align: center;
    padding: 48px 36px;
    gap: 16px;
}

.exam-result-screen.show { display: flex; }

.result-trophy {
    font-size: 5rem;
    line-height: 1;
    filter: drop-shadow(0 0 20px rgba(245,158,11,0.5));
    animation: trophy-bounce 0.8s ease;
}

@keyframes trophy-bounce {
    0% { transform: scale(0); opacity: 0; }
    70% { transform: scale(1.1); }
    100% { transform: scale(1); opacity: 1; }
}

.result-grade-badge {
    font-size: 3rem;
    font-weight: 900;
    width: 80px;
    height: 80px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto;
}

.grade-a { background: linear-gradient(135deg, #10b981, #059669); color: #fff; box-shadow: 0 0 30px rgba(16,185,129,0.4); }
.grade-b { background: linear-gradient(135deg, #00add8, #0081a2); color: #fff; box-shadow: 0 0 30px rgba(0,173,216,0.4); }
.grade-c { background: linear-gradient(135deg, #f59e0b, #d97706); color: #fff; box-shadow: 0 0 30px rgba(245,158,11,0.4); }
.grade-d { background: linear-gradient(135deg, #ef4444, #b91c1c); color: #fff; box-shadow: 0 0 30px rgba(239,68,68,0.4); }

.result-title { font-size: 1.8rem; font-weight: 900; color: #fff; letter-spacing: -0.02em; }
.result-score-big { font-size: 3.5rem; font-weight: 900; color: var(--go-blue); line-height: 1; }
.result-score-detail { font-size: 1rem; color: var(--text-muted); }
.result-feedback { font-size: 1.05rem; color: var(--text-muted); max-width: 480px; line-height: 1.7; }

.result-actions { display: flex; gap: 12px; margin-top: 8px; flex-wrap: wrap; justify-content: center; }
.btn-retry-exam { background: linear-gradient(135deg, var(--go-blue), var(--go-blue-dark)); color: #fff; border: none; padding: 12px 24px; border-radius: var(--radius-md); font-weight: 700; cursor: pointer; transition: var(--transition); }
.btn-retry-exam:hover { filter: brightness(1.12); transform: translateY(-1px); }

/* ══════════════════════════════════════════════════
   DEPLOYMENT DOMAIN BADGES
   ══════════════════════════════════════════════════ */

.badge-deploy {
    background: rgba(16,185,129,0.15);
    color: var(--accent-green);
    border: 1px solid rgba(16,185,129,0.3);
}

.badge-project {
    background: rgba(139,92,246,0.15);
    color: var(--accent-purple);
    border: 1px solid rgba(139,92,246,0.3);
}

.badge-exam {
    background: linear-gradient(135deg, rgba(245,158,11,0.2), rgba(239,68,68,0.2));
    color: var(--accent-amber);
    border: 1px solid rgba(245,158,11,0.4);
}

/* ══════════════════════════════════════════════════
   FINAL EXAM TRIGGER BUTTON IN SIDEBAR
   ══════════════════════════════════════════════════ */

.sidebar-exam-btn {
    margin: 12px 16px;
    background: linear-gradient(135deg, rgba(245,158,11,0.15), rgba(239,68,68,0.15));
    border: 1px solid rgba(245,158,11,0.35);
    color: var(--accent-amber);
    padding: 10px 16px;
    border-radius: var(--radius-md);
    cursor: pointer;
    font-weight: 700;
    font-size: 0.88rem;
    width: calc(100% - 32px);
    text-align: center;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.sidebar-exam-btn:hover {
    background: linear-gradient(135deg, rgba(245,158,11,0.25), rgba(239,68,68,0.25));
    transform: translateY(-1px);
}

/* ══════════════════════════════════════════════════
   IMPROVED THEORY STYLES (code block copy btn, etc.)
   ══════════════════════════════════════════════════ */

.code-box-header .copy-snippet-btn {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-dim);
    padding: 2px 10px;
    border-radius: 4px;
    font-size: 0.75rem;
    cursor: pointer;
    transition: var(--transition);
    font-family: var(--font-sans);
}

.code-box-header .copy-snippet-btn:hover {
    border-color: var(--go-blue);
    color: var(--go-blue);
}

/* Step blocks for deployment guides */
.step-block {
    display: flex;
    gap: 16px;
    padding: 16px 0;
    border-bottom: 1px solid var(--border-color);
}

.step-block:last-child { border-bottom: none; }

.step-num {
    width: 32px;
    height: 32px;
    background: linear-gradient(135deg, var(--go-blue), var(--go-blue-dark));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.85rem;
    font-weight: 800;
    color: #fff;
    flex-shrink: 0;
    margin-top: 2px;
}

.step-content h4 {
    font-size: 1rem;
    font-weight: 700;
    color: #fff;
    margin-bottom: 8px;
}

.step-content p {
    color: var(--text-muted);
    font-size: 0.9rem;
    line-height: 1.7;
    margin-bottom: 8px;
}

/* OS selector tabs for installation guides */
.os-tabs {
    display: flex;
    gap: 4px;
    margin: 12px 0;
}

.os-tab-btn {
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    color: var(--text-muted);
    padding: 6px 16px;
    border-radius: var(--radius-sm);
    font-size: 0.82rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.os-tab-btn.active {
    background: rgba(0,173,216,0.15);
    border-color: var(--go-blue);
    color: var(--go-blue);
}

.os-tab-content { display: none; }
.os-tab-content.active { display: block; }

/* Mini project chapter marker */
.section-title.project-domain {
    color: var(--accent-purple);
}

.section-title.exam-domain {
    color: var(--accent-amber);
}

.section-title.deploy-domain {
    color: var(--accent-green);
}

/* Chapter item type badges */
.chapter-type-icon {
    font-size: 0.7rem;
    margin-left: 4px;
    opacity: 0.7;
}

/* Wide screen improvements (2560px) */
@media (min-width: 1800px) {
    :root {
        --sidebar-width: 360px;
    }
    .main-content {
        padding: 40px 80px;
    }
    .theory-container, .quiz-container, .hard-quiz-container {
        max-width: 960px;
    }
}

/* ══════════════════════════════════════════════════
   ANIMATE ON CHAPTER LOAD
   ══════════════════════════════════════════════════ */

@keyframes fadeSlideIn {
    from { opacity: 0; transform: translateY(12px); }
    to   { opacity: 1; transform: translateY(0); }
}

.chapter-header,
.theory-container,
.quiz-container,
.hard-quiz-container,
.playground-container {
    animation: fadeSlideIn 0.3s ease forwards;
}

/* ══════════════════════════════════════════════════
   IMPROVED PROGRESS WIDGET
   ══════════════════════════════════════════════════ */

.progress-widget {
    cursor: help;
}

.progress-text {
    white-space: nowrap;
}

/* Keyboard shortcut hints */
.kbd-hint {
    font-family: var(--font-mono);
    background: rgba(255,255,255,0.08);
    border: 1px solid rgba(255,255,255,0.15);
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 0.75rem;
    color: var(--text-dim);
}

/* ==========================================================================
   PEMBELAJARAN — bright workbench layer
   The learning shell stays light; the editor and terminal remain dark tools.
   ========================================================================== */
.course-home {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    min-width: 0;
    padding-right: 17px;
    margin-right: 3px;
    border-right: 1px solid var(--border-color);
    color: var(--text-main);
    text-decoration: none;
    line-height: 1;
}
.course-home img {
    width: 31px;
    height: 31px;
    flex: 0 0 auto;
    filter: drop-shadow(0 3px 4px rgba(23, 62, 64, 0.14));
}
.course-home span { display: grid; gap: 4px; min-width: 0; }
.course-home b { font-size: .76rem; letter-spacing: -.02em; }
.course-home small {
    color: var(--text-dim);
    font-family: var(--font-mono);
    font-size: .57rem;
    font-weight: 700;
    letter-spacing: .08em;
    text-transform: uppercase;
}
.course-home:hover b { color: var(--go-blue); }

body {
    background:
        radial-gradient(circle at 92% 0, rgba(185, 221, 122, .2), transparent 23rem),
        var(--bg-dark);
}
::-webkit-scrollbar-track { background: var(--bg-dark); }
::-webkit-scrollbar-thumb { background: #c5d1c6; }
.app-header {
    background: rgba(255, 253, 248, .9);
    border-bottom-color: var(--border-color);
    box-shadow: 0 4px 18px rgba(23, 62, 64, .045);
}
.brand-icon {
    background: linear-gradient(135deg, var(--go-blue), var(--go-blue-dark));
    box-shadow: 0 6px 15px var(--go-blue-glow);
}
.brand-text h1 { color: var(--text-main); }
.app-sidebar {
    background: rgba(255, 253, 248, .75);
    border-right-color: var(--border-color);
}
.sidebar-header { color: var(--text-dim); }
.section-title { color: var(--go-blue); }
.chapter-item:hover { background: var(--bg-card-hover); }
.chapter-item.active {
    color: var(--text-main);
    background: rgba(8, 126, 122, .11);
    border-left-color: var(--go-blue);
}
.chapter-num { background: rgba(8, 126, 122, .09); color: var(--text-dim); }
.main-content { background: transparent; }
.chapter-header {
    border: 1px solid var(--border-color);
    background: linear-gradient(124deg, rgba(255, 253, 248, .97), rgba(229, 243, 235, .85));
    box-shadow: 0 12px 28px rgba(23, 62, 64, .055);
}
.chapter-header::before { background: linear-gradient(90deg, var(--go-blue), var(--accent-green), var(--accent-amber)); }
.chapter-header h2, .theory-section h3, .step-content h4 { color: var(--text-main); }
.chapter-desc, .theory-section p, .theory-section li { color: var(--text-muted); }
.badge {
    color: var(--go-blue-dark);
    border-color: rgba(8, 126, 122, .24);
    background: rgba(8, 126, 122, .1);
}
.video-timestamp { color: var(--text-dim); background: rgba(8, 126, 122, .065); border-color: rgba(8, 126, 122, .14); }
.tabs-nav { border-bottom-color: var(--border-color); }
.tab-btn { color: var(--text-dim); }
.tab-btn:hover { color: var(--text-main); background: rgba(185, 221, 122, .22); }
.tab-btn.active { color: var(--go-blue-dark); border-bottom-color: var(--go-blue); background: rgba(8, 126, 122, .075); }
.theory-container, .quiz-container, .hard-quiz-container {
    border-color: var(--border-color);
    background: rgba(255, 253, 248, .78);
    box-shadow: 0 7px 22px rgba(23, 62, 64, .04);
}
.theory-section h3::before { background: var(--coral, #ff754c); }
.callout { border-color: var(--border-color); }
.callout-info { background: rgba(8, 126, 122, .075); color: var(--text-main); }
.callout-warning { background: rgba(184, 120, 19, .08); color: var(--text-main); }
.callout-tip { background: rgba(95, 149, 60, .08); color: var(--text-main); }
.callout-title { color: var(--text-main); }
.tech-table { border-color: var(--border-color); }
.tech-table th { background: #e7f1e7; color: var(--text-main); }
.tech-table td { border-color: var(--border-color); color: var(--text-muted); }
.tech-table tr:nth-child(even) td { background: rgba(239, 245, 239, .68); }
.tech-table code, .theory-section code {
    color: var(--go-blue-dark);
    background: rgba(8, 126, 122, .08);
    border-color: rgba(8, 126, 122, .15);
}
.playground-container {
    border: 1px solid var(--border-color);
    background: var(--bg-card);
    box-shadow: 0 10px 24px rgba(23, 62, 64, .06);
}
.playground-toolbar, .engine-selector { background: #edf4ee; border-color: var(--border-color); color: var(--text-main); }
.engine-select { color: var(--text-main); background: var(--bg-card); border-color: var(--border-color); }
.btn-secondary { color: var(--text-main); background: var(--bg-card); border-color: var(--border-color); }
.btn-secondary:hover { color: var(--go-blue-dark); border-color: var(--go-blue); background: #edf4ee; }
.btn-primary, .btn-submit-exam, .btn-retry-exam {
    background: linear-gradient(135deg, var(--go-blue), var(--go-blue-dark));
    box-shadow: 0 4px 12px var(--go-blue-glow);
}
.quiz-question, .quiz-card, .hard-quiz-question {
    border-color: var(--border-color);
    background: var(--bg-card);
}
.quiz-option, .hard-quiz-option { border-color: var(--border-color); color: var(--text-muted); background: #fffdf8; }
.quiz-option:hover, .hard-quiz-option:hover { border-color: var(--go-blue); background: rgba(8, 126, 122, .06); }
.chapter-nav-bottom { border-top-color: var(--border-color); background: rgba(247, 243, 235, .88); }
.final-exam-overlay { background: rgba(23, 62, 64, .38); }
.final-exam-modal { border-color: var(--border-color); background: var(--bg-card); box-shadow: 0 24px 75px rgba(23, 62, 64, .25); }
.final-exam-modal-header { background: linear-gradient(130deg, #e2f1ec, #f4f1d8); }
.final-exam-modal-header h2, .hard-quiz-result-banner .result-title, .result-title { color: var(--text-main); }
.final-exam-modal-header p { color: var(--text-muted); }
.final-exam-footer { border-top-color: var(--border-color); background: #fffdf8; }
.kbd-hint { color: var(--text-dim); background: #edf4ee; border-color: var(--border-color); }
@media (max-width: 1024px) {
    .course-home { padding-right: 10px; margin-right: 0; }
    .course-home span { display: none; }
}
@media (max-width: 640px) {
    .course-home { border-right: 0; padding-right: 0; }
    .course-home img { width: 29px; height: 29px; }
}