/* ============================================== */
/* KB — Knowledge Base specific styles            */
/* Index cards, Category layout, Sidebar,         */
/* Article content, Article list, Back link        */
/* ============================================== */

/* --- KB Section (index page) --- */
.kb-section {
    padding: 48px 0 80px;
    background: var(--color-bg);
}
.kb-section__intro {
    text-align: center;
    max-width: none;
    margin: 0 auto 24px;
}
.kb-section__subtitle {
    font-size: 15px;
    line-height: 1.7;
    color: var(--color-text-secondary);
}

/* --- Category Grid --- */
.kb-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

/* --- Category Card --- */
.kb-card {
    display: flex;
    flex-direction: column;
    background: #fff;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: 32px 28px 28px;
    text-decoration: none;
    transition: border-color 0.25s, box-shadow 0.25s, transform 0.25s;
    position: relative;
    overflow: hidden;
}
.kb-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 3px;
    background: var(--gradient-brand);
    opacity: 0;
    transition: opacity 0.25s;
}
.kb-card:hover {
    border-color: var(--color-primary-light);
    box-shadow: 0 4px 20px rgba(74, 85, 230, 0.08), 0 1px 3px rgba(0,0,0,0.04);
    transform: translateY(-2px);
}
.kb-card:hover::before { opacity: 1; }

.kb-card__icon {
    width: 52px;
    height: 52px;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    flex-shrink: 0;
}
.kb-card__icon svg { width: 26px; height: 26px; stroke-width: 1.5; fill: none; }

/* Icon color variants */
.kb-card__icon--blue    { background: linear-gradient(135deg, #E8EAF6, #C5CAE9); }
.kb-card__icon--blue svg    { stroke: #3F51B5; }
.kb-card__icon--purple  { background: linear-gradient(135deg, #F3E5F5, #E1BEE7); }
.kb-card__icon--purple svg  { stroke: #7B1FA2; }
.kb-card__icon--teal    { background: linear-gradient(135deg, #E0F2F1, #B2DFDB); }
.kb-card__icon--teal svg    { stroke: #00796B; }
.kb-card__icon--orange  { background: linear-gradient(135deg, #FFF3E0, #FFE0B2); }
.kb-card__icon--orange svg  { stroke: #E65100; }
.kb-card__icon--green   { background: linear-gradient(135deg, #E8F5E9, #C8E6C9); }
.kb-card__icon--green svg   { stroke: #2E7D32; }
.kb-card__icon--red     { background: linear-gradient(135deg, #FFEBEE, #FFCDD2); }
.kb-card__icon--red svg     { stroke: #C62828; }
.kb-card__icon--indigo  { background: linear-gradient(135deg, #E8EAF6, #9FA8DA); }
.kb-card__icon--indigo svg  { stroke: #283593; }
.kb-card__icon--grey    { background: linear-gradient(135deg, #F5F5F5, #E0E0E0); }
.kb-card__icon--grey svg    { stroke: #546E7A; }

.kb-card__name {
    font-size: 17px;
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: 8px;
    line-height: 1.3;
}
.kb-card__desc {
    font-size: 13px;
    line-height: 1.6;
    color: var(--color-text-muted);
    margin-bottom: 20px;
    flex: 1;
}
.kb-card__meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 16px;
    border-top: 1px solid var(--color-border-light);
}
.kb-card__articles {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 12px;
    font-weight: 600;
    color: var(--color-text-muted);
}
.kb-card__articles svg { width: 14px; height: 14px; stroke: var(--color-primary); fill: none; stroke-width: 2; }
.kb-card__arrow {
    width: 28px;
    height: 28px;
    border-radius: 8px;
    background: var(--color-bg);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.2s, transform 0.2s;
}
.kb-card__arrow svg { width: 14px; height: 14px; stroke: var(--color-text-muted); fill: none; stroke-width: 2; }
.kb-card:hover .kb-card__arrow {
    background: var(--color-primary-light);
    transform: translateX(2px);
}
.kb-card:hover .kb-card__arrow svg { stroke: var(--color-primary); }

/* --- Bottom text --- */
.kb-bottom {
    text-align: center;
    margin-top: 48px;
    padding: 32px;
    background: #fff;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
}
.kb-bottom__text {
    font-size: 14px;
    line-height: 1.7;
    color: var(--color-text-secondary);
    max-width: none;
    margin: 0 auto;
}
.kb-bottom__text strong { color: var(--color-text); }

/* ============================================== */
/* CATEGORY LAYOUT — Two-column with sidebar      */
/* ============================================== */
.cat-section {
    padding: 48px 0 80px;
    background: var(--color-bg);
}
.cat-grid {
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: 28px;
    align-items: start;
}
.cat-main { min-width: 0; }

/* --- Sidebar --- */
.cat-sidebar { position: sticky; top: 80px; }
.sidebar-nav {
    background: #fff;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: 24px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.04);
}
.sidebar-nav__title {
    font-size: 13px;
    font-weight: 700;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--color-border-light);
    display: flex;
    align-items: center;
    gap: 8px;
}
.sidebar-nav__title svg { width: 15px; height: 15px; stroke: var(--color-primary); fill: none; stroke-width: 2; }
.sidebar-nav__list { list-style: none; margin: 0; padding: 0; }
.sidebar-nav__item { margin-bottom: 2px; }
.sidebar-nav__link {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
    padding: 9px 12px;
    border-radius: var(--radius-md);
    text-decoration: none;
    font-size: 13px;
    font-weight: 500;
    color: var(--color-text-secondary);
    transition: background 0.2s, color 0.2s;
}
.sidebar-nav__link:hover { background: var(--color-bg); color: var(--color-primary); }
.sidebar-nav__link--active { background: var(--color-primary-light, #EDE7F6); color: var(--color-primary); font-weight: 600; }
.sidebar-nav__link--active:hover { background: var(--color-primary-light, #EDE7F6); }
.sidebar-nav__count {
    font-size: 11px;
    font-weight: 600;
    color: var(--color-text-muted);
    background: var(--color-bg);
    padding: 2px 8px;
    border-radius: 20px;
    min-width: 20px;
    text-align: center;
    flex-shrink: 0;
}
.sidebar-nav__link--active .sidebar-nav__count { background: #fff; color: var(--color-primary); }

/* --- Category header --- */
.cat-header {
    display: flex;
    align-items: center;
    gap: 20px;
    margin-bottom: 32px;
    padding: 28px 32px;
    background: #fff;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    box-shadow: 0 1px 3px rgba(0,0,0,0.04);
}
.cat-header__icon {
    width: 56px;
    height: 56px;
    border-radius: 16px;
    background: linear-gradient(135deg, #E3F2FD, #BBDEFB);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}
.cat-header__icon svg { width: 28px; height: 28px; stroke: #1565C0; fill: none; stroke-width: 1.5; }

/* Category icon color variants (synced with kb-card__icon--*) */
.cat-header__icon--blue    { background: linear-gradient(135deg, #E8EAF6, #C5CAE9); }
.cat-header__icon--blue svg    { stroke: #3F51B5; }
.cat-header__icon--purple  { background: linear-gradient(135deg, #F3E5F5, #E1BEE7); }
.cat-header__icon--purple svg  { stroke: #7B1FA2; }
.cat-header__icon--teal    { background: linear-gradient(135deg, #E0F2F1, #B2DFDB); }
.cat-header__icon--teal svg    { stroke: #00796B; }
.cat-header__icon--orange  { background: linear-gradient(135deg, #FFF3E0, #FFE0B2); }
.cat-header__icon--orange svg  { stroke: #E65100; }
.cat-header__icon--green   { background: linear-gradient(135deg, #E8F5E9, #C8E6C9); }
.cat-header__icon--green svg   { stroke: #2E7D32; }
.cat-header__icon--red     { background: linear-gradient(135deg, #FFEBEE, #FFCDD2); }
.cat-header__icon--red svg     { stroke: #C62828; }
.cat-header__icon--indigo  { background: linear-gradient(135deg, #E8EAF6, #9FA8DA); }
.cat-header__icon--indigo svg  { stroke: #283593; }
.cat-header__icon--grey    { background: linear-gradient(135deg, #F5F5F5, #E0E0E0); }
.cat-header__icon--grey svg    { stroke: #546E7A; }
.cat-header__info { flex: 1; }
.cat-header__name { font-size: 20px; font-weight: 700; color: var(--color-text); margin-bottom: 4px; }
.cat-header__desc { font-size: 14px; color: var(--color-text-muted); line-height: 1.5; }
.cat-header__badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 14px;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    font-size: 12px;
    font-weight: 600;
    color: var(--color-text-muted);
    flex-shrink: 0;
}
.cat-header__badge svg { width: 14px; height: 14px; stroke: var(--color-primary); fill: none; stroke-width: 2; }

/* --- Article list --- */
.article-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}
.article-card {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 20px 24px;
    background: #fff;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    text-decoration: none;
    transition: border-color 0.2s, box-shadow 0.2s, transform 0.2s;
}
.article-card:hover {
    border-color: var(--color-primary-light);
    box-shadow: 0 2px 12px rgba(74, 85, 230, 0.08);
    transform: translateX(4px);
}
.article-card__num {
    width: 36px;
    height: 36px;
    border-radius: 10px;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 13px;
    font-weight: 700;
    color: var(--color-primary);
    flex-shrink: 0;
}
.article-card__content { flex: 1; min-width: 0; }
.article-card__title {
    font-size: 15px;
    font-weight: 600;
    color: var(--color-text);
    line-height: 1.4;
    transition: color 0.2s;
}
.article-card:hover .article-card__title { color: var(--color-primary); }
.article-card__arrow {
    width: 28px;
    height: 28px;
    border-radius: 8px;
    background: var(--color-bg);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    transition: background 0.2s, transform 0.2s;
}
.article-card__arrow svg { width: 14px; height: 14px; stroke: var(--color-text-muted); fill: none; stroke-width: 2; }
.article-card:hover .article-card__arrow { background: var(--color-primary-light); transform: translateX(2px); }
.article-card:hover .article-card__arrow svg { stroke: var(--color-primary); }

/* ============================================== */
/* ARTICLE CONTENT — Rich text styling            */
/* ============================================== */
.article-content {
    background: #fff;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: 48px 56px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.04), 0 8px 32px rgba(0,0,0,0.06);
}
.article-content h2 {
    font-size: 22px;
    font-weight: 700;
    color: var(--color-text);
    margin: 40px 0 16px;
    padding-top: 24px;
    border-top: 1px solid var(--color-border-light);
    letter-spacing: -0.01em;
}
.article-content h2:first-child { margin-top: 0; padding-top: 0; border-top: none; }
.article-content h3 {
    font-size: 17px;
    font-weight: 600;
    color: var(--color-text);
    margin: 28px 0 12px;
}
.article-content p {
    font-size: 15px;
    line-height: 1.7;
    color: var(--color-text-secondary);
    margin: 0 0 16px;
}
.article-content ul,
.article-content ol {
    font-size: 15px;
    line-height: 1.7;
    color: var(--color-text-secondary);
    margin: 0 0 16px;
    padding-left: 24px;
}
.article-content ul { list-style: disc; }
.article-content ol { list-style: decimal; }
.article-content ul li,
.article-content ol li { margin-bottom: 6px; }
.article-content li::marker { color: var(--color-primary); }
.article-content strong { color: var(--color-text); font-weight: 600; }
.article-content a {
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}
.article-content a:hover {
    color: var(--color-accent);
    text-decoration: underline;
    text-underline-offset: 3px;
}
.article-content img {
    max-width: 100%;
    width: auto;
    height: auto;
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
    margin: 16px 0;
}
.article-content table {
    width: 100%;
    border-collapse: collapse;
    margin: 16px 0;
    font-size: 14px;
    line-height: 1.6;
}
.article-content table th {
    background: var(--color-bg);
    color: var(--color-text);
    font-weight: 600;
    text-align: left;
    padding: 12px 16px;
    border: 1px solid var(--color-border);
}
.article-content table td {
    padding: 10px 16px;
    border: 1px solid var(--color-border);
    color: var(--color-text-secondary);
}
.article-content table tr:nth-child(even) td { background: var(--color-bg); }
.article-content table td strong { color: var(--color-text); }
.article-content blockquote {
    margin: 16px 0;
    padding: 16px 20px;
    background: var(--color-bg);
    border-left: 4px solid var(--color-primary);
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    font-size: 14px;
    line-height: 1.7;
    color: var(--color-text-secondary);
}
.article-content pre {
    margin: 16px 0;
    padding: 20px;
    background: #1E1E2E;
    border-radius: var(--radius-lg);
    overflow-x: auto;
}
.article-content code {
    font-family: var(--font-mono);
    font-size: 13px;
}
.article-content pre code { color: #CDD6F4; }
.article-content p code {
    background: var(--color-bg);
    padding: 2px 8px;
    border-radius: var(--radius-sm, 4px);
    font-size: 13px;
    color: var(--color-primary);
    border: 1px solid var(--color-border);
}

/* --- Back to KB link --- */
.cat-back { margin-top: 48px; text-align: center; }
.cat-back__link {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 28px;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    font-size: 14px;
    font-weight: 600;
    color: var(--color-text-secondary);
    text-decoration: none;
    transition: border-color 0.2s, color 0.2s, box-shadow 0.2s, background 0.2s;
}
.cat-back__link svg {
    width: 18px;
    height: 18px;
    fill: none;
    stroke: currentColor;
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
    flex-shrink: 0;
}
.cat-back__link:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
    background: #f0f5ff;
    box-shadow: 0 2px 8px rgba(37, 99, 235, 0.1);
}

/* ============================================== */
/* KB RESPONSIVE                                  */
/* ============================================== */
@media (max-width: 900px) {
    .kb-grid { grid-template-columns: repeat(2, 1fr); }
    .cat-grid { grid-template-columns: 1fr; }
    .cat-sidebar { position: static; }
    .cat-header { flex-wrap: wrap; }
}
@media (max-width: 640px) {
    .kb-section { padding: 32px 0 60px; }
    .kb-section__intro { margin-bottom: 32px; }
    .kb-grid { grid-template-columns: 1fr; gap: 16px; }
    .kb-card { padding: 24px 20px 20px; }
    .kb-card__icon { width: 44px; height: 44px; border-radius: 12px; margin-bottom: 16px; }
    .kb-card__icon svg { width: 22px; height: 22px; }
    .kb-card__name { font-size: 15px; }
    .kb-bottom { padding: 24px 20px; margin-top: 32px; }
    .article-content { padding: 28px 20px; }
    .cat-header { padding: 20px; }
    .article-card { padding: 16px; }
}