body.route-about .site-main,
html[data-theme="dark"] body.route-about .site-main {
    background: #fcfcfd !important;
}

body.route-about .site-breadcrumbs-inner { max-width: 848px; }

.about-reference-page {
    --about-bg: #fcfcfd;
    --about-surface: #fff;
    --about-primary: #0f2537;
    --about-primary-hover: #1a3a54;
    --about-text: #1e293b;
    --about-muted: #64748b;
    --about-soft: #94a3b8;
    --about-border: #e7ebf0;
    --about-border-strong: #cbd5e1;
    --about-accent: #2e68b5;
    background: var(--about-bg);
    color: var(--about-text);
    font-family: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

.about-reference-page *,
.about-reference-page *::before,
.about-reference-page *::after { box-sizing: border-box; }

.about-reference-container {
    width: min(100%, 848px);
    margin: 0 auto;
    padding: 0 24px;
}

.about-reference-header {
    padding: 48px 0 40px;
    border-bottom: 1px solid var(--about-border);
}

.about-reference-eyebrow,
.about-reference-section-label {
    display: block;
    margin: 0 0 10px;
    color: var(--about-accent);
    font-size: .74rem;
    font-weight: 600;
    letter-spacing: .12em;
    text-transform: uppercase;
}

.about-reference-header h1 {
    margin: 0;
    color: var(--about-primary);
    font: 500 clamp(1.9rem, 4.5vw, 2.5rem)/1.15 Lora, Georgia, serif;
    letter-spacing: -.015em;
}

.about-reference-header p {
    max-width: 640px;
    margin: 9px 0 0;
    color: var(--about-muted);
    font-size: .95rem;
    line-height: 1.55;
}

.about-reference-layout {
    display: flex;
    flex-direction: column;
    gap: 36px;
    padding: 40px 0 72px;
}

.about-reference-section-label {
    margin-bottom: 12px;
    color: var(--about-soft);
    font-size: .72rem;
    letter-spacing: .1em;
}

.about-intro-card,
.about-principles-card,
.about-content-card,
.about-explore-card {
    border: 1px solid var(--about-border);
    border-radius: 14px;
    background: var(--about-surface);
    box-shadow: 0 1px 2px rgba(15, 37, 55, .04);
}

.about-intro-card {
    display: grid;
    grid-template-columns: 62px 1fr;
    gap: 22px;
    padding: 28px;
}

.about-intro-mark {
    display: flex;
    width: 58px;
    height: 58px;
    align-items: center;
    justify-content: center;
    border: 1px solid #c9d8eb;
    border-radius: 50%;
    color: var(--about-primary);
    font: 500 1.45rem Lora, Georgia, serif;
}

.about-intro-card h2,
.about-principles-card h2,
.about-content-card h2,
.about-explore-card h2 {
    margin: 0 0 6px;
    color: var(--about-primary);
    font-size: .97rem;
    font-weight: 600;
}

.about-intro-card p,
.about-principles-card p,
.about-content-card p,
.about-explore-card p {
    margin: 0;
    color: var(--about-muted);
    font-size: .86rem;
    line-height: 1.65;
}

.about-intro-card p + p { margin-top: 10px; }
.about-principles-card,
.about-content-card { overflow: hidden; }

.about-principles-card article {
    display: grid;
    grid-template-columns: 44px 1fr;
    gap: 14px;
    padding: 20px 24px;
    border-bottom: 1px solid var(--about-border);
}

.about-principles-card article:last-child,
.about-content-card article:last-child { border-bottom: 0; }

.about-principle-number {
    color: var(--about-accent);
    font: 500 .78rem "SFMono-Regular", Consolas, monospace;
    letter-spacing: .06em;
}

.about-content-card article {
    padding: 22px 24px;
    border-bottom: 1px solid var(--about-border);
}

.about-explore-card {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
    padding: 24px;
}

.about-explore-actions { display: flex; flex: 0 0 auto; gap: 10px; }

.about-reference-button {
    display: inline-flex;
    min-height: 40px;
    align-items: center;
    justify-content: center;
    padding: 9px 16px;
    border: 1px solid var(--about-primary);
    border-radius: 9px;
    background: var(--about-primary);
    color: #fff;
    font-size: .82rem;
    font-weight: 600;
    text-decoration: none;
    white-space: nowrap;
}

.about-reference-button:hover { border-color: var(--about-primary-hover); background: var(--about-primary-hover); color: #fff; }
.about-reference-button.is-secondary { border-color: var(--about-border-strong); background: #fff; color: var(--about-muted); }
.about-reference-button.is-secondary:hover { border-color: var(--about-muted); background: #f8fafc; color: var(--about-text); }

@media (max-width: 680px) {
    .about-reference-container { padding: 0 18px; }
    .about-reference-header { padding: 34px 0 32px; }
    .about-reference-layout { gap: 30px; padding: 32px 0 52px; }
    .about-intro-card { grid-template-columns: 1fr; padding: 22px 18px; }
    .about-principles-card article { grid-template-columns: 36px 1fr; padding: 19px 18px; }
    .about-content-card article { padding: 20px 18px; }
    .about-explore-card { align-items: flex-start; flex-direction: column; padding: 22px 18px; }
    .about-explore-actions { width: 100%; flex-direction: column; }
    .about-reference-button { width: 100%; }
}