/* Cloudflare Docs Modern Theme - MAS Courseware */
:root {
    --primary: #F6821F;
    --primary-hover: #EB6E08;
    --primary-tint: rgba(246, 130, 31, 0.08);

    --bg-page: #FFFFFF;
    --bg-surface: #F9FAFB;
    --bg-sidebar: #F9FAFB;
    --bg-card: #FFFFFF;
    --bg-code: #1E293B;

    --text-main: #111827;
    --text-muted: #4B5563;
    --text-subtle: #6B7280;

    --border-color: #E5E7EB;
    --border-subtle: #F3F4F6;
    
    --callout-def-border: #2563EB;
    --callout-def-bg: #EFF6FF;
    --callout-note-border: #F59E0B;
    --callout-note-bg: #FFFBEB;
    --callout-comm-border: #10B981;
    --callout-comm-bg: #ECFDF5;
    --callout-assign-border: #8B5CF6;
    --callout-assign-bg: #F5F3FF;

    --sidebar-width: 280px;
    --toc-width: 240px;
    --header-height: 60px;
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-mono: ui-monospace, "SF Mono", Monaco, Consolas, "Liberation Mono", Menlo, monospace;
}

[data-theme="dark"] {
    --primary: #F6821F;
    --primary-hover: #FA9A4B;
    --primary-tint: rgba(246, 130, 31, 0.15);

    --bg-page: #0F172A;
    --bg-surface: #1E293B;
    --bg-sidebar: #131B2E;
    --bg-card: #1E293B;
    --bg-code: #090D16;

    --text-main: #F8FAFC;
    --text-muted: #94A3B8;
    --text-subtle: #64748B;

    --border-color: #334155;
    --border-subtle: #1E293B;

    --callout-def-border: #3B82F6;
    --callout-def-bg: #172554;
    --callout-note-border: #F59E0B;
    --callout-note-bg: #451A03;
    --callout-comm-border: #10B981;
    --callout-comm-bg: #064E3B;
    --callout-assign-border: #A78BFA;
    --callout-assign-bg: #2E1065;
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background-color: var(--bg-page);
    color: var(--text-main);
    line-height: 1.68;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
}

/* Header */
.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    height: var(--header-height);
    background-color: var(--bg-page);
    border-bottom: 1px solid var(--border-color);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
    padding: 0 1.5rem;
}

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

.brand-link {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    text-decoration: none;
    color: var(--text-main);
    font-weight: 700;
    font-size: 1.05rem;
}

.brand-logo {
    width: 26px;
    height: 26px;
}

.brand-badge {
    background-color: var(--primary-tint);
    color: var(--primary);
    font-size: 0.72rem;
    font-weight: 700;
    padding: 0.15rem 0.45rem;
    border-radius: 4px;
    letter-spacing: 0.04em;
}

.header-search {
    flex: 1;
    max-width: 420px;
    margin: 0 1.5rem;
}

.search-input-wrap {
    position: relative;
    display: flex;
    align-items: center;
}

.search-icon {
    position: absolute;
    left: 0.75rem;
    width: 16px;
    height: 16px;
    color: var(--text-subtle);
}

.search-input-wrap input {
    width: 100%;
    padding: 0.45rem 0.75rem 0.45rem 2.2rem;
    font-size: 0.88rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background-color: var(--bg-surface);
    color: var(--text-main);
    outline: none;
}

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

.header-right {
    display: flex;
    align-items: center;
    gap: 0.6rem;
}

.sidebar-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text-main);
    cursor: pointer;
    padding: 0.4rem;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0.42rem 0.75rem;
    font-size: 0.82rem;
    font-weight: 600;
    border-radius: 6px;
    text-decoration: none;
    cursor: pointer;
    border: 1px solid transparent;
}

.btn-outline {
    border-color: var(--border-color);
    background-color: transparent;
    color: var(--text-main);
}

.btn-outline:hover {
    background-color: var(--bg-surface);
    border-color: var(--text-subtle);
}

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

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

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

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

.theme-toggle {
    background: none;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 0.45rem;
    color: var(--text-main);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle:hover {
    background-color: var(--bg-surface);
}

[data-theme="light"] .moon-icon { display: none; }
[data-theme="dark"] .sun-icon { display: none; }

.sun-icon, .moon-icon {
    width: 16px;
    height: 16px;
}

/* Layout */
.layout-container {
    display: flex;
    min-height: calc(100vh - var(--header-height));
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    flex-shrink: 0;
    background-color: var(--bg-sidebar);
    border-right: 1px solid var(--border-color);
    height: calc(100vh - var(--header-height));
    position: sticky;
    top: var(--header-height);
    overflow-y: auto;
    padding: 1.25rem 0.75rem 2rem 0.75rem;
    display: flex;
    flex-direction: column;
}

.sidebar-header {
    padding: 0 0.5rem 0.75rem 0.5rem;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 0.75rem;
}

.sidebar-subtitle {
    font-size: 0.72rem;
    font-weight: 700;
    color: var(--text-subtle);
    letter-spacing: 0.08em;
}

.sidebar-nav {
    flex: 1;
}

.nav-group {
    margin-bottom: 1.2rem;
}

.nav-group-title {
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--text-subtle);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    padding: 0.3rem 0.5rem;
}

.nav-list {
    list-style: none;
    margin-top: 0.25rem;
}

.nav-item {
    margin-bottom: 0.15rem;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.35rem 0.5rem;
    border-radius: 5px;
    text-decoration: none;
    color: var(--text-muted);
    font-size: 0.85rem;
    line-height: 1.35;
}

.nav-link:hover {
    background-color: var(--border-subtle);
    color: var(--text-main);
}

.nav-link.active {
    background-color: var(--primary-tint);
    color: var(--primary);
    font-weight: 600;
}

.nav-number {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--text-subtle);
    min-width: 1.3rem;
}

.nav-link.active .nav-number {
    color: var(--primary);
}

.sidebar-footer {
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
    font-size: 0.75rem;
    color: var(--text-subtle);
}

/* Main Content Area */
.main-content {
    flex: 1;
    min-width: 0;
    padding: 2rem 3rem 4rem 3rem;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.doc-article {
    width: 100%;
    max-width: 820px;
}

/* TOC Sidebar */
.toc-sidebar {
    width: var(--toc-width);
    flex-shrink: 0;
    height: calc(100vh - var(--header-height));
    position: sticky;
    top: var(--header-height);
    overflow-y: auto;
    padding: 2rem 1rem;
    display: block;
}

.toc-title {
    font-size: 0.78rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-subtle);
    margin-bottom: 0.75rem;
}

.toc-list {
    list-style: none;
    border-left: 1px solid var(--border-color);
}

.toc-item {
    margin-bottom: 0.4rem;
}

.toc-link {
    display: block;
    padding-left: 0.75rem;
    font-size: 0.82rem;
    color: var(--text-muted);
    text-decoration: none;
    line-height: 1.4;
    border-left: 2px solid transparent;
    margin-left: -1px;
}

.toc-link:hover {
    color: var(--text-main);
    border-left-color: var(--primary);
}

/* Breadcrumb */
.breadcrumb {
    margin-bottom: 1.25rem;
}

.breadcrumb ol {
    list-style: none;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.82rem;
    color: var(--text-subtle);
}

.breadcrumb a {
    color: var(--text-subtle);
    text-decoration: none;
}

.breadcrumb a:hover {
    color: var(--primary);
}

.breadcrumb li + li::before {
    content: "/";
    margin-right: 0.5rem;
    color: var(--border-color);
}

/* Article Header */
.article-header {
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 1.5rem;
    margin-bottom: 2rem;
}

.chapter-badge {
    display: inline-block;
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 0.06em;
    color: var(--primary);
    background-color: var(--primary-tint);
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    margin-bottom: 0.75rem;
}

.article-title {
    font-size: 2.1rem;
    font-weight: 800;
    line-height: 1.25;
    letter-spacing: -0.02em;
    color: var(--text-main);
    margin-bottom: 0.6rem;
}

.article-summary {
    font-size: 1.05rem;
    color: var(--text-muted);
    line-height: 1.55;
    margin-bottom: 0.85rem;
}

.article-meta {
    display: flex;
    gap: 0.5rem;
    font-size: 0.82rem;
    color: var(--text-subtle);
}

/* Article Body Typography */
.article-body h2 {
    font-size: 1.45rem;
    font-weight: 700;
    letter-spacing: -0.015em;
    color: var(--text-main);
    margin: 2.5rem 0 1rem 0;
    padding-bottom: 0.4rem;
    border-bottom: 1px solid var(--border-color);
}

.article-body h3 {
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--text-main);
    margin: 1.8rem 0 0.75rem 0;
}

.article-body p {
    margin-bottom: 1.15rem;
    color: var(--text-main);
}

.article-body ul, .article-body ol {
    margin: 0 0 1.25rem 1.5rem;
    color: var(--text-main);
}

.article-body li {
    margin-bottom: 0.35rem;
}

.article-body a {
    color: var(--primary);
    text-decoration: underline;
    text-underline-offset: 3px;
}

.article-body a:hover {
    color: var(--primary-hover);
}

.article-body code:not(pre code) {
    font-family: var(--font-mono);
    font-size: 0.87em;
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    padding: 0.15em 0.35em;
    border-radius: 4px;
    color: var(--text-main);
}

/* Callouts */
.callout {
    border-left: 4px solid transparent;
    border-radius: 0 6px 6px 0;
    margin: 1.5rem 0;
    padding: 1rem 1.25rem;
}

.callout-header {
    display: flex;
    align-items: center;
    gap: 0.45rem;
    margin-bottom: 0.45rem;
}

.callout-icon {
    width: 17px;
    height: 17px;
}

.callout-badge {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.callout-body {
    font-size: 0.94rem;
    line-height: 1.55;
}

.callout-body p:last-child {
    margin-bottom: 0;
}

.callout-definition {
    border-left-color: var(--callout-def-border);
    background-color: var(--callout-def-bg);
}
.callout-definition .callout-badge,
.callout-definition .callout-icon {
    color: var(--callout-def-border);
}

.callout-note {
    border-left-color: var(--callout-note-border);
    background-color: var(--callout-note-bg);
}
.callout-note .callout-badge,
.callout-note .callout-icon {
    color: var(--callout-note-border);
}

.callout-commentary {
    border-left-color: var(--callout-comm-border);
    background-color: var(--callout-comm-bg);
}
.callout-commentary .callout-badge,
.callout-commentary .callout-icon {
    color: var(--callout-comm-border);
}

.callout-assignment {
    border-left-color: var(--callout-assign-border);
    background-color: var(--callout-assign-bg);
}
.callout-assignment .callout-badge,
.callout-assignment .callout-icon {
    color: var(--callout-assign-border);
}

/* Code Blocks */
.code-container {
    background-color: var(--bg-code);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    margin: 1.5rem 0;
    overflow: hidden;
}

.code-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background-color: rgba(0, 0, 0, 0.2);
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    padding: 0.4rem 0.85rem;
}

.code-language {
    font-family: var(--font-mono);
    font-size: 0.74rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: #94A3B8;
}

.code-copy-btn {
    display: flex;
    align-items: center;
    gap: 0.3rem;
    background: transparent;
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: 4px;
    color: #CBD5E1;
    font-size: 0.74rem;
    padding: 0.2rem 0.5rem;
    cursor: pointer;
}

.code-copy-btn:hover {
    background-color: rgba(255, 255, 255, 0.1);
    color: #FFFFFF;
}

.copy-icon {
    width: 12px;
    height: 12px;
}

pre.highlight {
    padding: 1rem 1.25rem;
    overflow-x: auto;
    font-family: var(--font-mono);
    font-size: 0.86rem;
    line-height: 1.55;
    color: #F8FAFC;
    background-color: var(--bg-code);
}

/* Images & Figures */
.image-wrapper {
    margin: 1.75rem 0;
    text-align: center;
}

.content-image {
    max-width: 100%;
    height: auto;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background-color: #FFFFFF; /* Ensures transparent UML diagrams are crisp in dark mode */
    padding: 0.5rem;
}

/* Videos */
.video-wrapper {
    margin: 1.75rem 0;
    text-align: center;
}

.content-video {
    width: 100%;
    max-width: 100%;
    border-radius: 6px;
    border: 1px solid var(--border-color);
    background-color: #000;
}

/* Quizzes */
.quiz-widget {
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background-color: var(--bg-surface);
    padding: 1.25rem;
    margin: 1.75rem 0;
}

.quiz-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 0.75rem;
}

.quiz-tag {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--primary);
}

.quiz-icon {
    width: 16px;
    height: 16px;
}

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

.quiz-question {
    font-weight: 600;
    font-size: 1.02rem;
    margin-bottom: 0.85rem;
}

.quiz-options {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.quiz-option {
    display: flex;
    align-items: flex-start;
    gap: 0.65rem;
    padding: 0.6rem 0.85rem;
    background-color: var(--bg-page);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.92rem;
}

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

.quiz-checkbox {
    margin-top: 0.25rem;
    width: 16px;
    height: 16px;
    accent-color: var(--primary);
}

.quiz-actions {
    display: flex;
    gap: 0.6rem;
}

.quiz-feedback {
    margin-top: 0.85rem;
    padding: 0.65rem 0.85rem;
    border-radius: 5px;
    font-size: 0.88rem;
    font-weight: 600;
}

.quiz-feedback.correct {
    background-color: var(--callout-comm-bg);
    color: var(--callout-comm-border);
    border: 1px solid var(--callout-comm-border);
}

.quiz-feedback.incorrect {
    background-color: #FEF2F2;
    color: #DC2626;
    border: 1px solid #DC2626;
}

.quiz-explanation {
    margin-top: 0.85rem;
    padding: 0.75rem 1rem;
    background-color: var(--bg-page);
    border: 1px solid var(--border-color);
    border-radius: 5px;
    font-size: 0.88rem;
    line-height: 1.5;
}

.quiz-explanation ul {
    margin: 0.4rem 0 0 1.25rem;
}

/* Option visual feedback */
.quiz-option.opt-correct {
    background-color: var(--callout-comm-bg);
    border-color: var(--callout-comm-border);
}

.quiz-option.opt-wrong {
    background-color: #FEF2F2;
    border-color: #EF4444;
}

/* Chapter Pager */
.chapter-pager {
    display: flex;
    justify-content: space-between;
    gap: 1rem;
    margin-top: 3.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.pager-card {
    display: flex;
    flex-direction: column;
    padding: 1rem 1.25rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    text-decoration: none;
    color: var(--text-main);
    flex: 1;
}

.pager-card:hover {
    border-color: var(--primary);
    background-color: var(--primary-tint);
}

.pager-next {
    text-align: right;
}

.pager-label {
    font-size: 0.75rem;
    color: var(--text-subtle);
    margin-bottom: 0.25rem;
}

.pager-title {
    font-weight: 600;
    font-size: 0.95rem;
}

.pager-placeholder {
    flex: 1;
}

/* Site Footer */
.site-footer {
    width: 100%;
    max-width: 820px;
    margin-top: 3rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
    font-size: 0.8rem;
    color: var(--text-subtle);
    text-align: center;
}

/* Home / Index Hero & Grid */
.hero-section {
    width: 100%;
    max-width: 820px;
    padding: 2.5rem 0 2rem 0;
    text-align: center;
}

.hero-badge {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    color: var(--primary);
    background-color: var(--primary-tint);
    padding: 0.25rem 0.6rem;
    border-radius: 4px;
    margin-bottom: 1rem;
}

.hero-title {
    font-size: 2.5rem;
    font-weight: 800;
    letter-spacing: -0.025em;
    line-height: 1.2;
    margin-bottom: 1rem;
    color: var(--text-main);
}

.hero-lead {
    font-size: 1.15rem;
    color: var(--text-muted);
    max-width: 700px;
    margin: 0 auto 1.75rem auto;
    line-height: 1.6;
}

.hero-actions {
    display: flex;
    justify-content: center;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.btn-hero-primary {
    background-color: var(--primary);
    color: #FFFFFF;
    font-weight: 600;
    padding: 0.65rem 1.25rem;
    border-radius: 6px;
    text-decoration: none;
    font-size: 0.92rem;
}

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

.btn-hero-secondary {
    background-color: var(--bg-surface);
    color: var(--text-main);
    border: 1px solid var(--border-color);
    font-weight: 600;
    padding: 0.65rem 1.25rem;
    border-radius: 6px;
    text-decoration: none;
    font-size: 0.92rem;
}

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

.stats-bar {
    display: flex;
    justify-content: space-around;
    width: 100%;
    max-width: 820px;
    padding: 1.25rem 0;
    margin: 1.5rem 0 2.5rem 0;
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
}

.stat-item {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 1.6rem;
    font-weight: 800;
    color: var(--primary);
}

.stat-label {
    font-size: 0.78rem;
    color: var(--text-subtle);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.curriculum-container {
    width: 100%;
    max-width: 820px;
}

.module-section {
    margin-bottom: 2.25rem;
}

.module-heading {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-main);
}

.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
    gap: 0.85rem;
}

.module-card {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem 1.15rem;
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    text-decoration: none;
    color: var(--text-main);
}

.module-card:hover {
    border-color: var(--primary);
    background-color: var(--primary-tint);
}

.card-num {
    font-family: var(--font-mono);
    font-size: 1.1rem;
    font-weight: 800;
    color: var(--primary);
    background-color: var(--bg-surface);
    width: 40px;
    height: 40px;
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.card-content {
    flex: 1;
    min-width: 0;
}

.card-title {
    font-size: 0.95rem;
    font-weight: 600;
    margin-bottom: 0.2rem;
    color: var(--text-main);
}

.card-desc {
    font-size: 0.8rem;
    color: var(--text-muted);
    line-height: 1.35;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.card-arrow {
    color: var(--text-subtle);
    flex-shrink: 0;
}

.module-card:hover .card-arrow {
    color: var(--primary);
}

/* Responsive */
@media (max-width: 1200px) {
    .toc-sidebar {
        display: none;
    }
}

@media (max-width: 900px) {
    .sidebar-toggle {
        display: block;
    }

    .sidebar {
        position: fixed;
        left: -100%;
        top: var(--header-height);
        height: calc(100vh - var(--header-height));
        z-index: 40;
        background-color: var(--bg-page);
    }

    .sidebar.open {
        left: 0;
    }

    .main-content {
        padding: 1.5rem 1rem 3rem 1rem;
    }

    .header-search {
        display: none;
    }

    .cards-grid {
        grid-template-columns: 1fr;
    }
}