/*  HERO BANNER  */
.hero-banner {
    background: linear-gradient(135deg,
            var(--accent-dark) 0%,
            var(--primary-color) 60%,
            #2a6fa8 100%);
    padding: 56px 0 48px;
    position: relative;
    overflow: hidden;
}

.hero-banner::before {
    content: "";
    position: absolute;
    inset: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.04'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.hero-banner .badge-tag {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: rgba(201, 162, 77, 0.2);
    border: 1px solid rgba(201, 162, 77, 0.4);
    color: #fbd38d;
    font-size: 12px;
    font-weight: 600;
    padding: 5px 14px;
    border-radius: 20px;
    letter-spacing: 0.5px;
    margin-bottom: 18px;
}

.hero-banner h1 {
    font-size: clamp(26px, 4vw, 42px);
    font-weight: 800;
    color: #fff;
    line-height: 1.2;
    margin-bottom: 16px;
}

.hero-banner h1 span {
    color: #fbd38d;
}

.hero-banner p {
    font-size: var(--paragraph-large-size);
    font-weight: var(--paragraph-large-weight);
    color: rgba(255, 255, 255, 0.82);
    max-width: 640px;
    line-height: 1.7;
    margin-bottom: 28px;
}

.hero-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    margin-bottom: 28px;
}

.hero-meta-item {
    display: flex;
    align-items: center;
    gap: 7px;
    font-size: var(--paragraph-small-size);
    color: rgba(255, 255, 255, 0.75);
}

.hero-meta-item i {
    color: var(--secondary-color);
    font-size: 13px;
}

/*  HERO CODE  */
.hero-code-preview {
    background: rgba(0, 0, 0, 0.35);
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: 12px;
    overflow: hidden;
    backdrop-filter: blur(4px);
}

.code-header {
    background: rgba(0, 0, 0, 0.25);
    padding: 10px 16px;
    display: flex;
    align-items: center;
    gap: 8px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.code-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
}

.code-dot.red {
    background: #ff5f57;
}

.code-dot.yellow {
    background: #febc2e;
}

.code-dot.green {
    background: #28c840;
}

.code-filename {
    font-size: 12px;
    color: rgba(255, 255, 255, 0.5);
    margin-left: 8px;
    font-family: monospace;
}

.code-body {
    padding: 20px;
    font-family: "Courier New", monospace;
    font-size: 13px;
    line-height: 1.7;
}

/* Syntax tokens */
.py-keyword {
    color: #79b8ff;
}

.py-builtin {
    color: #d2a679;
}

.py-string {
    color: #9ecbff;
}

.py-comment {
    color: #6a9955;
    font-style: italic;
}

.py-fn {
    color: #b392f0;
}

.py-num {
    color: #f8c555;
}

.py-plain {
    color: #e1e4e8;
}

.py-class {
    color: #ffd700;
}

/*  READING PROGRESS BAR  */
.reading-progress {
    position: fixed;
    top: 0;
    left: 0;
    width: 0%;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    z-index: 9999;
    transition: width 0.1s;
}

/*  MAIN LAYOUT  */
.main-wrapper {
    padding: 32px 0 60px;
}

.order-lg-2>.toc-card {
    display: none;
}

/*  SIDEBAR  */
.sidebar-sticky {
    position: sticky;
    top: 22%;
    max-height: calc(100vh - 40px);
    overflow-y: auto;
    scrollbar-width: thin;
    scrollbar-color: var(--border-color) transparent;
}

/*  TOC CARD  */
.toc-card {
    background: var(--background-white);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    overflow: hidden;
}

.toc-card-header {
    background: linear-gradient(135deg, var(--accent-dark), var(--primary-color));
    padding: 16px 20px;
    color: #fff;
    font-size: var(--paragraph-small-size);
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 8px;
}

.toc-list {
    list-style: none;
    padding: 8px 0;
    margin: 0;
}

.toc-list li a {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 9px 20px;
    font-size: var(--paragraph-small-size);
    font-weight: 400;
    color: var(--text-dark);
    text-decoration: none;
    transition: all 0.15s;
    border-left: 3px solid transparent;
}

.toc-list li a:hover,
.toc-list li a.active {
    background: var(--hover-bg);
    border-left-color: var(--primary-color);
    color: var(--primary-color);
}

.toc-list li a i {
    font-size: 12px;
    color: var(--secondary-color);
    width: 14px;
}

/*  PROMO CARD  */
.promo-card {
    background: linear-gradient(135deg, #f0faf9, #d6efed);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 20px;
    margin-top: 24px;
    text-align: center;
}

.promo-card .promo-icon {
    font-size: 32px;
    margin-bottom: 10px;
    color: var(--primary-color);
}

.promo-card h5 {
    font-size: var(--paragraph-medium-size);
    font-weight: 700;
    color: var(--accent-dark);
    margin-bottom: 6px;
}

.promo-card p {
    font-size: 12px;
    color: var(--text-muted);
    margin-bottom: 14px;
}

.btn-promo {
    display: block;
    background: var(--primary-color);
    color: #fff;
    padding: 10px;
    border-radius: 8px;
    font-size: var(--paragraph-small-size);
    font-weight: 600;
    text-decoration: none;
    transition: 0.2s;
}

.btn-promo:hover {
    background: var(--accent-dark);
    color: #fff;
}

/*  STATS STRIP  */
.stats-strip {
    background: linear-gradient(135deg, var(--accent-dark), var(--primary-color));
    border-radius: 12px;
    padding: 24px 28px;
    margin-bottom: 24px;
    display: flex;
    align-items: center;
    justify-content: space-around;
    flex-wrap: wrap;
    gap: 20px;
}

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

.stat-item .stat-number {
    font-size: 28px;
    font-weight: 800;
    color: #fff;
    display: block;
}

.stat-item .stat-label {
    font-size: 12px;
    color: rgba(255, 255, 255, 0.65);
    font-weight: 500;
}

.stat-divider {
    width: 1px;
    height: 40px;
    background: rgba(255, 255, 255, 0.15);
}

/*  INTRO CARD  */
.intro-card {
    background: var(--background-white);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 28px 32px;
    margin-bottom: 24px;
}

.last-updated {
    font-size: 12px;
    color: var(--text-muted);
    margin-bottom: 14px;
    display: flex;
    align-items: center;
    gap: 6px;
}

.last-updated i {
    color: var(--secondary-color);
}

.intro-card h2 {
    font-size: var(--heading-2-size);
    font-weight: var(--heading-2-weight);
    color: var(--text-dark);
    margin-bottom: 16px;
    line-height: 1.25;
}

.intro-card p {
    font-size: var(--paragraph-large-size);
    font-weight: var(--paragraph-large-weight);
    color: var(--text-muted);
    line-height: 1.75;
    margin-bottom: 16px;
}

.intro-points {
    list-style: none;
    margin: 18px 0 24px;
    padding: 0;
}

.intro-points li {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    font-size: var(--paragraph-normal-size);
    font-weight: var(--paragraph-normal-weight);
    color: var(--text-dark);
    margin-bottom: 10px;
    line-height: 1.7;
}

.intro-points li i {
    color: var(--primary-color);
    margin-top: 4px;
    font-size: 12px;
    flex-shrink: 0;
}

.intro-points li strong {
    font-weight: 700;
    color: var(--accent-dark);
}

.intro-points li span {
    flex: 1;
}

/*  HIGHLIGHT BOX  */
.highlight-box {
    background: var(--hover-bg);
    border-left: 4px solid var(--primary-color);
    border-radius: 0 8px 8px 0;
    padding: 14px 18px;
    margin: 16px 0;
    font-size: var(--paragraph-normal-size);
    color: var(--text-dark);
    line-height: 1.6;
}

.highlight-box strong {
    color: var(--primary-color);
}

/*  FEATURES GRID  */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 14px;
    margin: 20px 0;
}

.feature-card {
    background: var(--background-light);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 16px;
    transition: 0.2s;
}

.feature-card:hover {
    border-color: var(--primary-color);
    background: var(--hover-bg);
    transform: translateY(-2px);
}

.feature-card i {
    font-size: 22px;
    color: var(--primary-color);
    margin-bottom: 10px;
    display: block;
}

.feature-card h5 {
    font-size: var(--paragraph-small-size);
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 5px;
}

.feature-card p {
    font-size: 12px;
    color: var(--text-muted);
    line-height: 1.5;
}

/*  PREREQ CARD  */
.prereq-card {
    background: #f0faf9;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 20px 24px;
    margin-bottom: 24px;
    display: flex;
    align-items: flex-start;
    gap: 14px;
}

.prereq-icon {
    font-size: 24px;
    color: var(--secondary-color);
    margin-top: 2px;
    flex-shrink: 0;
}

.prereq-content h5 {
    font-size: var(--paragraph-large-size);
    font-weight: 700;
    color: var(--accent-dark);
    margin-bottom: 8px;
}

.prereq-content p {
    font-size: var(--paragraph-normal-size);
    color: var(--text-muted);
    margin-bottom: 10px;
}

.prereq-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.prereq-tag {
    background: var(--background-white);
    border: 1px solid var(--border-secondary-color);
    color: var(--accent-dark);
    font-size: 12px;
    font-weight: 600;
    padding: 4px 12px;
    border-radius: 16px;
    text-decoration: none;
    transition: 0.15s;
}

.prereq-tag:hover {
    background: var(--primary-color);
    color: #fff;
    border-color: var(--primary-color);
}

/*  QUICK START CARD  */
.quick-start-card {
    background: var(--background-white);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 28px 32px;
    margin-bottom: 24px;
}

.section-title {
    font-size: var(--heading-3-size);
    font-weight: var(--heading-3-weight);
    color: var(--text-dark);
    margin-bottom: 6px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.section-title::after {
    content: "";
    flex: 1;
    height: 2px;
    background: linear-gradient(to right, var(--border-color), transparent);
    margin-left: 8px;
}

.section-subtitle {
    font-size: var(--paragraph-normal-size);
    color: var(--text-muted);
    margin-bottom: 20px;
}

/*  APPS GRID  */
.apps-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: 12px;
    margin: 16px 0;
}

.app-card {
    background: var(--background-light);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 16px 12px;
    text-align: center;
    transition: 0.2s;
}

.app-card:hover {
    border-color: var(--primary-color);
    background: var(--hover-bg);
}

.app-card i {
    font-size: 24px;
    color: var(--primary-color);
    margin-bottom: 8px;
    display: block;
}

.app-card span {
    font-size: var(--paragraph-small-size);
    font-weight: 600;
    color: var(--text-dark);
}

/*  COMPARISON TABLE  */
.comparison-table {
    width: 100%;
    border-collapse: collapse;
    margin: 16px 0;
}

.comparison-table th {
    background: var(--accent-dark);
    color: #fff;
    padding: 12px 16px;
    font-size: var(--paragraph-small-size);
    font-weight: 700;
    text-align: left;
}

.comparison-table th:first-child {
    border-radius: 8px 0 0 0;
}

.comparison-table th:last-child {
    border-radius: 0 8px 0 0;
}

.comparison-table td {
    padding: 10px 16px;
    font-size: var(--paragraph-small-size);
    color: var(--text-dark);
    border-bottom: 1px solid var(--border-color);
}

.comparison-table tr:nth-child(even) td {
    background: var(--background-light);
}

.comparison-table tr:hover td {
    background: var(--hover-bg);
}

.badge-yes {
    color: #16a34a;
    font-weight: 700;
}

.badge-no {
    color: #dc2626;
    font-weight: 700;
}

/*  TOPIC SECTIONS  */
.topic-section {
    background: var(--background-white);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    margin-bottom: 24px;
    overflow: hidden;
}

.topic-section-header {
    padding: 20px 24px 16px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: flex-start;
    gap: 14px;
}

/* Icon wrap */
.topic-icon-wrap {
    width: 44px;
    height: 44px;
    border-radius: 10px;
    background: linear-gradient(135deg, var(--accent-dark), var(--primary-color));
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.topic-icon-wrap i {
    color: #fff;
    font-size: 18px;
}

.topic-icon-wrap.secondary {
    background: linear-gradient(135deg, #744210, #d97706);
}

.topic-icon-wrap.soft {
    background: linear-gradient(135deg, #1a7a60, #27a085);
}

.topic-icon-wrap.purple {
    background: linear-gradient(135deg, #4a3080, #7b52c8);
}

.topic-icon-wrap.red {
    background: linear-gradient(135deg, #8b2020, #c84040);
}

.topic-icon-wrap.blue {
    background: linear-gradient(135deg, #1a4a8b, #2d72d9);
}

.topic-icon-wrap.orange {
    background: linear-gradient(135deg, #8b4500, #d97706);
}

.topic-icon-wrap.teal {
    background: linear-gradient(135deg, #0f5e5e, #0d9488);
}

.topic-icon-wrap.green {
    background: linear-gradient(135deg, #14532d, #16a34a);
}

.topic-icon-wrap.indigo {
    background: linear-gradient(135deg, #312e81, #4f46e5);
}

.topic-icon-wrap.pink {
    background: linear-gradient(135deg, #831843, #db2777);
}

.topic-icon-wrap.cyan {
    background: linear-gradient(135deg, #164e63, #0891b2);
}

.topic-icon-wrap.amber {
    background: linear-gradient(135deg, #78350f, #d97706);
}

.topic-icon-wrap.lime {
    background: linear-gradient(135deg, #365314, #65a30d);
}

.topic-icon-wrap.rose {
    background: linear-gradient(135deg, #881337, #e11d48);
}

.topic-icon-wrap.sky {
    background: linear-gradient(135deg, #0c4a6e, #0284c7);
}

.topic-title-wrap h3 {
    font-size: var(--heading-4-size);
    font-weight: var(--heading-4-weight);
    color: var(--text-dark);
    margin-bottom: 4px;
}

.topic-title-wrap p {
    font-size: var(--paragraph-small-size);
    color: var(--text-muted);
    line-height: 1.5;
}

.topic-links-grid {
    padding: 16px 24px 20px;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 6px;
}

.topic-link {
    display: flex;
    align-items: center;
    gap: 9px;
    padding: 9px 12px;
    border-radius: 8px;
    text-decoration: none;
    color: var(--text-dark);
    font-size: var(--paragraph-small-size);
    font-weight: 400;
    transition: all 0.15s;
    border: 1px solid transparent;
}

.topic-link:hover {
    background: var(--hover-bg);
    border-color: var(--border-color);
    color: var(--primary-color);
}

.topic-link i {
    font-size: 11px;
    color: var(--primary-color);
    flex-shrink: 0;
}

/*  CODE BLOCK  */
.code-block {
    background: #0d1117;
    border-radius: 10px;
    overflow: hidden;
    margin-bottom: 24px;
}

.code-block-header {
    background: #161b22;
    padding: 10px 16px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid #30363d;
}

.code-lang-badge {
    font-size: 11px;
    font-weight: 700;
    color: var(--secondary-color);
    background: rgba(201, 162, 77, 0.15);
    padding: 2px 8px;
    border-radius: 4px;
    letter-spacing: 0.5px;
}

.code-copy-btn {
    background: none;
    border: 1px solid #30363d;
    color: #8b949e;
    font-size: 11px;
    padding: 4px 10px;
    border-radius: 5px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 5px;
    transition: 0.15s;
}

.code-copy-btn:hover {
    border-color: #8b949e;
    color: #e6edf3;
}

.code-block pre {
    padding: 20px;
    margin: 0;
    overflow-x: auto;
    font-family: "Courier New", monospace;
    font-size: 13px;
    line-height: 1.75;
    color: #e1e4e8;
}

/*  FEEDBACK ROW  */
.feedback-row {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px 20px;
    background: var(--background-light);
    border-top: 1px solid var(--border-color);
    font-size: var(--paragraph-small-size);
    color: var(--text-muted);
    flex-wrap: wrap;
}

.feedback-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 7px 16px;
    border-radius: 20px;
    border: 1px solid var(--border-color);
    background: var(--background-white);
    font-size: var(--paragraph-small-size);
    font-weight: 600;
    cursor: pointer;
    transition: 0.15s;
    color: var(--text-dark);
}

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

.feedback-btn i {
    font-size: 12px;
}

/*  HERO ACTIONS  */
.btn-hero-primary {
    background: var(--secondary-color);
    color: #fff;
    border: none;
    padding: 12px 28px;
    border-radius: 8px;
    font-size: var(--paragraph-normal-size);
    font-weight: 700;
    cursor: pointer;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    transition: 0.2s;
}

.btn-hero-primary:hover {
    background: #b8902e;
    color: #fff;
    transform: translateY(-1px);
}

.btn-hero-outline {
    background: transparent;
    color: #fff;
    border: 2px solid rgba(255, 255, 255, 0.4);
    padding: 11px 24px;
    border-radius: 8px;
    font-size: var(--paragraph-normal-size);
    font-weight: 600;
    cursor: pointer;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    transition: 0.2s;
}

.btn-hero-outline:hover {
    border-color: #fff;
    background: rgba(255, 255, 255, 0.1);
    color: #fff;
}

/*  RESPONSIVE  */
@media (max-width: 991.98px) {
    .sidebar-sticky {
        position: static;
        max-height: none;
    }

    .stat-divider {
        display: none;
    }

    .order-lg-2>.toc-card {
        display: block;
    }

    .sidebar-sticky>.toc-card {
        display: none;
    }
}

@media (max-width: 767.98px) {
    .hero-banner {
        padding: 36px 0 32px;
    }

    .intro-card,
    .quick-start-card {
        padding: 20px;
    }

    .topic-links-grid {
        grid-template-columns: 1fr 1fr;
    }

    .stats-strip {
        padding: 18px 20px;
    }

    .stat-item .stat-number {
        font-size: 22px;
    }
}

@media (max-width: 575.98px) {
    .topic-links-grid {
        grid-template-columns: 1fr;
    }

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

    .apps-grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .app-card {
        padding: 10px 0;
    }

    .app-card i {
        font-size: 15px;
    }

    .app-card span {
        font-size: 10px;
    }

    .feedback-row {
        justify-content: center;
        gap: 10px;
    }
}