.page-header { margin: 8px 0 24px; }
.page-header h1 {
    font-size: var(--text-h2);
    font-weight: var(--fw-semibold);
    letter-spacing: -0.028em;
    color: var(--color-text-primary);
    margin: 0 0 8px;
    line-height: 1.1;
}
.page-header .page-subtitle {
    font-size: var(--text-lg);
    color: var(--color-text-secondary);
    letter-spacing: -0.01em;
    line-height: 1.45;
    margin: 0;
    max-width: 560px;
}

.kb-split {
    display: grid;
    grid-template-columns: 240px 1fr;
    gap: 24px;
    align-items: start;
}
body[data-subnav="off"] .kb-split { grid-template-columns: 1fr; }
body[data-subnav="off"] .kb-split > .kb-aside { display: none; }
body[data-subnav-side="right"] .kb-split { grid-template-columns: 1fr 240px; }
body[data-subnav-side="right"] .kb-split > .kb-aside { grid-column: 2; grid-row: 1; }
body[data-subnav-side="right"] .kb-split > .kb-main { grid-column: 1; grid-row: 1; }
body[data-subnav-side="outside"] .kb-split,
body[data-subnav-side="outside-left"] .kb-split { grid-template-columns: 1fr; position: relative; }
body[data-subnav-side="outside"] .kb-split > .kb-aside,
body[data-subnav-side="outside-left"] .kb-split > .kb-aside { position: absolute; top: 0; width: 240px; }
body[data-subnav-side="outside"] .kb-split > .kb-aside { left: calc(100% + 24px); }
body[data-subnav-side="outside-left"] .kb-split > .kb-aside { right: calc(100% + 24px); left: auto; }
body[data-subnav-side="outside"]:not([data-layout="top"]):not([data-align="left"]):not([data-align="content"]) .ph-main-wrap .content-area { transform: translateX(-132px); }
body[data-subnav-side="outside-left"]:not([data-layout="top"]):not([data-align="left"]):not([data-align="content"]) .ph-main-wrap .content-area { transform: translateX(132px); }

.kb-aside { display: flex; flex-direction: column; gap: 16px; }
.kb-main { display: flex; flex-direction: column; gap: 12px; }

.subnav-card { padding: 8px; }
.subnav-heading {
    font-size: var(--text-xs);
    font-weight: var(--fw-semibold);
    color: var(--color-text-tertiary);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    padding: 10px 12px 8px;
}
.subnav-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 12px;
    border-radius: var(--radius-sm);
    color: var(--color-text-primary);
    font-size: var(--text-base);
    letter-spacing: -0.008em;
    text-decoration: none;
    transition: background var(--transition-fast);
}
.subnav-item:hover { background: var(--sidebar-item-hover); color: var(--color-text-primary); text-decoration: none; }
.subnav-item.active { background: var(--sidebar-item-active); font-weight: var(--fw-medium); }
.subnav-item svg { width: 14px; height: 14px; color: var(--color-text-tertiary); flex-shrink: 0; }
.subnav-item.active svg { color: var(--color-accent); }

/* Article header */
.article-head {
    padding: 24px 28px 20px;
    border-bottom: 0.5px solid var(--color-border);
}
.article-title {
    font-size: var(--text-h4);
    font-weight: var(--fw-semibold);
    letter-spacing: -0.02em;
    color: var(--color-text-primary);
    line-height: 1.2;
    margin: 0 0 10px;
}
.article-meta {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: var(--text-sm);
    color: var(--color-text-tertiary);
    flex-wrap: wrap;
}

/* Article body */
.article-body { padding: 24px 28px 28px; }
.article-body p {
    font-size: var(--text-lg);
    line-height: 1.65;
    color: var(--color-text-primary);
    margin: 0 0 16px;
    letter-spacing: -0.003em;
}
.article-body p:last-child { margin-bottom: 0; }
.article-body h2 {
    font-size: var(--text-2xl);
    font-weight: var(--fw-semibold);
    letter-spacing: -0.014em;
    color: var(--color-text-primary);
    margin: 28px 0 10px;
}
.article-body h2:first-child { margin-top: 0; }
.article-body h3 {
    font-size: var(--text-xl);
    font-weight: var(--fw-semibold);
    letter-spacing: -0.012em;
    color: var(--color-text-primary);
    margin: 22px 0 8px;
}
.article-body ul,
.article-body ol {
    margin: 0 0 20px;
    padding-left: 0;
    list-style: none;
    counter-reset: step;
}
.article-body li {
    font-size: var(--text-lg);
    line-height: 1.65;
    color: var(--color-text-primary);
    padding-left: 28px;
    position: relative;
    margin-bottom: 10px;
    letter-spacing: -0.003em;
}
.article-body ul > li::before {
    content: "";
    position: absolute;
    left: 8px;
    top: 10px;
    width: 5px;
    height: 5px;
    border-radius: 50%;
    background: var(--color-text-tertiary);
}
.article-body ol > li { counter-increment: step; }
.article-body ol > li::before {
    content: counter(step);
    position: absolute;
    left: 0;
    top: 0;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: var(--color-accent-light);
    color: var(--color-accent);
    font-size: var(--text-xs);
    font-weight: var(--fw-semibold);
    display: flex;
    align-items: center;
    justify-content: center;
}
.article-body strong { font-weight: var(--fw-semibold); color: var(--color-text-primary); }
.article-body code {
    font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
    font-size: var(--text-base);
    background: var(--color-surface-secondary);
    padding: 1px 6px;
    border-radius: 4px;
    color: var(--color-text-primary);
}
.article-body pre {
    background: var(--color-surface-secondary);
    padding: 14px 16px;
    border-radius: var(--radius-md);
    overflow-x: auto;
    font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
    font-size: var(--text-base);
    line-height: 1.55;
    margin: 0 0 20px;
}
.article-body blockquote {
    margin: 20px 0;
    padding: 12px 16px;
    border-left: 3px solid var(--color-accent);
    background: var(--color-accent-light);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    font-size: var(--text-md);
    color: var(--color-text-primary);
    font-style: italic;
}
.article-body a { color: var(--color-accent); text-decoration: underline; text-decoration-thickness: 0.5px; text-underline-offset: 2px; }
.article-body img {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-md);
    margin: 16px 0;
}

/* Helpful vote */
.helpful-card {
    padding: 20px 24px;
    text-align: center;
}
.helpful-title {
    font-size: var(--text-lg);
    font-weight: var(--fw-semibold);
    letter-spacing: -0.01em;
    color: var(--color-text-primary);
    margin: 0 0 14px;
}
.helpful-actions {
    display: inline-flex;
    gap: 10px;
    margin-bottom: 14px;
}
.helpful-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    height: 36px;
    padding: 0 18px;
    border-radius: var(--radius-pill);
    background: var(--color-surface-secondary);
    color: var(--color-text-primary);
    border: 1px solid var(--color-border-card);
    font-family: inherit;
    font-size: var(--text-base);
    font-weight: var(--fw-medium);
    cursor: pointer;
    transition: all var(--transition-fast);
}
.helpful-btn:hover { background: var(--color-surface); color: var(--color-accent); border-color: var(--color-accent); }
.helpful-btn.yes:hover { color: var(--color-green-text); border-color: var(--color-green-text); background: var(--color-green-bg); }
.helpful-btn.no:hover  { color: var(--color-red-text);   border-color: var(--color-red-text);   background: var(--color-red-bg); }
.helpful-btn svg { width: 14px; height: 14px; }
.helpful-stats {
    font-size: var(--text-sm);
    color: var(--color-text-tertiary);
    margin: 0;
}
.helpful-stats strong { color: var(--color-text-primary); font-weight: var(--fw-semibold); }
.helpful-thanks {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: var(--text-md);
    font-weight: var(--fw-medium);
    color: var(--color-green-text);
    margin: 0;
}

/* Related articles */
.related-head {
    padding: 16px 20px 10px;
    font-size: var(--text-xs);
    font-weight: var(--fw-semibold);
    color: var(--color-text-tertiary);
    text-transform: uppercase;
    letter-spacing: 0.06em;
}
.related-row {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 14px 20px;
    border-top: 0.5px solid var(--color-border);
    text-decoration: none;
    color: inherit;
    transition: background var(--transition-fast);
}
.related-row:hover { background: var(--color-surface-secondary); color: inherit; text-decoration: none; }
.related-row .rel-info { flex: 1; min-width: 0; }
.related-row .rel-title {
    font-size: var(--text-md);
    font-weight: var(--fw-medium);
    color: var(--color-text-primary);
    letter-spacing: -0.008em;
}
.related-row .rel-date {
    font-size: var(--text-sm);
    color: var(--color-text-tertiary);
    margin-top: 2px;
}
.related-row .rel-chev {
    color: var(--color-text-tertiary);
    transition: transform var(--transition-fast), color var(--transition-fast);
}
.related-row .rel-chev svg { width: 14px; height: 14px; }
.related-row:hover .rel-chev { color: var(--color-accent); transform: translateX(2px); }

/* Empty state */
.kb-empty {
    padding: 56px 24px 48px;
    text-align: center;
    color: var(--color-text-secondary);
}
.kb-empty-ico {
    width: 52px;
    height: 52px;
    border-radius: 50%;
    background: var(--color-surface-secondary);
    color: var(--color-text-tertiary);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 14px;
}
.kb-empty-ico svg { width: 22px; height: 22px; }
.kb-empty-title {
    font-size: var(--text-lg);
    font-weight: var(--fw-medium);
    color: var(--color-text-primary);
    margin: 0 0 4px;
    letter-spacing: -0.01em;
}
.kb-empty-sub {
    font-size: var(--text-base);
    color: var(--color-text-tertiary);
    margin: 0 auto 18px;
    max-width: 340px;
    line-height: 1.45;
}

@media (max-width: 1100px) {
    body[data-subnav-side="outside"] .kb-split,
    body[data-subnav-side="outside-left"] .kb-split { grid-template-columns: 240px 1fr; gap: 24px; position: static; }
    body[data-subnav-side="outside"] .kb-split > .kb-aside,
    body[data-subnav-side="outside-left"] .kb-split > .kb-aside { position: static; width: auto; left: auto; right: auto; }
    body[data-subnav-side="outside"]:not([data-layout="top"]):not([data-align="left"]):not([data-align="content"]) .ph-main-wrap .content-area,
    body[data-subnav-side="outside-left"]:not([data-layout="top"]):not([data-align="left"]):not([data-align="content"]) .ph-main-wrap .content-area { transform: none; }
}

@media (max-width: 880px) {
    .kb-split,
    body[data-subnav-side="right"] .kb-split,
    body[data-subnav-side="outside"] .kb-split,
    body[data-subnav-side="outside-left"] .kb-split { grid-template-columns: 1fr; }
    /* Stacked: show the content first, push the sub-nav below. */
    .kb-split > .kb-main { order: 1; }
    .kb-split > .kb-aside { order: 2; }
    body[data-subnav-side="right"] .kb-split > .kb-main,
    body[data-subnav-side="right"] .kb-split > .kb-aside { grid-column: auto; grid-row: auto; }
    .page-header h1 { font-size: var(--text-h3); }
    .article-title { font-size: var(--text-3xl); }
    .article-head { padding: 20px 20px 16px; }
    .article-body { padding: 20px 20px 24px; }
}

@media (max-width: 480px) {
    .page-header h1 { font-size: var(--text-h4); }
    .article-title { font-size: var(--text-2xl); }
    .helpful-actions { flex-direction: column; }
    .helpful-btn { width: 100%; justify-content: center; }
}