/* Docs — two-column layout, stacked section switching with motion,
   masthead lender grid with monochrome-to-colour hover.
   Back affordance: see .site-back in core.css (shared across all pages). */

.docs {
    display: grid;
    grid-template-columns: 220px 1fr;
    gap: 64px;
    max-width: 1200px;
    margin: 0 auto;
    padding: 120px 60px 80px;
    min-height: calc(100vh - 140px);
}

.docs-side {
    position: sticky;
    top: 120px;
    align-self: start;
}

.docs-side-links {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.docs-side-links a {
    font-size: clamp(13px, 0.5vw + 6px, 14px);
    font-weight: 400;
    color: var(--text-tertiary);
    letter-spacing: 0.01em;
    transition: color var(--dur-hover);
}

.docs-side-links a:hover { color: var(--text-secondary); }
.docs-side-links a:active { color: var(--text); }
.docs-side-links a.active { color: var(--text); }

/* Sections share a single grid cell (see .stack on .docs-main). Inactive
   sections must be fully removed from hit-testing, the tab order, and the
   accessibility tree — otherwise clicks on whitespace land on the tallest
   (Lenders) section's descendants, whose own `pointer-events: auto` (set by
   e.g. .docs-lender-grid--active) overrides an inherited `none` from the
   wrapping section. `visibility: hidden` blocks events unconditionally and
   propagates to descendants regardless of their own pointer-events value.
   The transition-delay pattern keeps the fade animation intact. */
.docs-section {
    opacity: 0;
    transform: translateY(8px);
    visibility: hidden;
    transition: opacity var(--dur-state) var(--ease-state),
                transform var(--dur-state) var(--ease-state),
                visibility 0s linear var(--dur-state);
    grid-area: 1 / 1;
}

.docs-section.docs-section--active {
    opacity: 1;
    transform: translateY(0);
    visibility: visible;
    transition: opacity var(--dur-state) var(--ease-state),
                transform var(--dur-state) var(--ease-state),
                visibility 0s linear 0s;
}

.docs-display {
    margin-bottom: 24px;
    max-width: 20ch;
}

.docs-band {
    margin: 40px 0;
    opacity: 0.8;
}

.docs-anatomy {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    margin-top: 32px;
}

.docs-anatomy-step {
    display: flex;
    flex-direction: column;
    gap: 8px;
    padding-top: 16px;
    border-top: 1px solid var(--border-light);
}

.docs-anatomy-label {
    font-size: 10px;
    font-weight: 500;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--text-tertiary);
}

.docs-anatomy-step p {
    font-size: clamp(13px, 0.5vw + 6px, 14px);
    line-height: 1.55;
    color: var(--text-secondary);
}

.docs-queries {
    display: flex;
    flex-direction: column;
    gap: 28px;
    margin-top: 32px;
}

.docs-query {
    display: grid;
    grid-template-columns: minmax(220px, 1fr) 2fr;
    gap: 32px;
    padding: 20px 0;
    border-top: 1px solid var(--border-light);
}

.docs-query-input {
    font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
    font-size: clamp(13px, 0.5vw + 6px, 14px);
    color: var(--text);
    padding-top: 2px;
}

.docs-query-output {
    font-size: clamp(13px, 0.5vw + 6px, 14px);
}

.docs-value-row {
    display: grid;
    grid-template-columns: 80px 1fr;
    gap: 16px;
    padding: 6px 0;
}

.docs-value-number { font-weight: 500; color: var(--text); }
.docs-value-lenders { color: var(--text-secondary); }

.docs-verdict {
    display: grid;
    grid-template-columns: 90px 1fr;
    gap: 16px;
    padding: 6px 10px;
    margin-bottom: 4px;
}

.docs-verdict-label {
    font-weight: 500;
    font-size: 11px;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    padding-top: 2px;
}

.docs-verdict-lenders { color: var(--text-secondary); }

.docs-verdict--yes { background: var(--yes-bg); }
.docs-verdict--yes .docs-verdict-label { color: var(--yes); }
.docs-verdict--refer { background: var(--refer-bg); }
.docs-verdict--refer .docs-verdict-label { color: var(--refer); }
.docs-verdict--no { background: var(--no-bg); }
.docs-verdict--no .docs-verdict-label { color: var(--no); }

.docs-policy-row {
    display: grid;
    grid-template-columns: 100px 1fr;
    gap: 16px;
    padding: 8px 0;
}

.docs-policy-lender { font-weight: 500; color: var(--text); }
.docs-policy-text { color: var(--text-secondary); }

.docs-provenance {
    display: flex;
    flex-direction: column;
    margin-top: 32px;
}

.docs-provenance-row {
    display: grid;
    grid-template-columns: 180px 1fr;
    gap: 32px;
    padding: 20px 0;
    border-top: 1px solid var(--border-light);
}

.docs-provenance-row:last-child {
    border-bottom: 1px solid var(--border-light);
}

.docs-provenance dt {
    font-size: 11px;
    font-weight: 500;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--text-tertiary);
    padding-top: 2px;
}

.docs-provenance dd {
    font-size: clamp(13px, 0.5vw + 6px, 14px);
    line-height: 1.6;
    color: var(--text-secondary);
}

.docs-lender-tabs {
    display: flex;
    gap: 24px;
    margin: 32px 0 24px;
    border-bottom: 1px solid var(--border-light);
}

.docs-lender-tab {
    font-size: clamp(12px, 0.5vw + 5px, 13px);
    font-weight: 400;
    color: var(--text-tertiary);
    padding: 8px 0;
    border: none;
    background: none;
    cursor: pointer;
    border-bottom: 1.5px solid transparent;
    margin-bottom: -1px;
    transition: color var(--dur-hover);
    letter-spacing: 0.01em;
}

.docs-lender-tab:hover { color: var(--text-secondary); }
.docs-lender-tab:active { color: var(--text); }
.docs-lender-tab--active {
    color: var(--text);
    border-bottom-color: var(--text);
}

.docs-lender-grids { display: grid; }

.docs-lender-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2px;
    grid-area: 1 / 1;
    align-content: start;
    justify-items: center;
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--dur-state) var(--ease-state),
                visibility 0s linear var(--dur-state);
}

/* Scope the inner grid's visibility to when its wrapping section is
   ALSO active. A bare `.docs-lender-grid--active { visibility: visible }`
   would override the outer `.docs-section { visibility: hidden }` (CSS
   visibility cascades but any descendant `visible` wins over a parent
   `hidden`) — which left the Residential grid clickable from other
   sections. */
.docs-section--active .docs-lender-grid.docs-lender-grid--active {
    opacity: 1;
    visibility: visible;
    transition: opacity var(--dur-state) var(--ease-state),
                visibility 0s linear 0s;
}

a.docs-lender-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    padding: 20px 12px;
    text-align: center;
    text-decoration: none;
    color: inherit;
    transition: background var(--dur-hover);
}

a.docs-lender-card:hover {
    background: var(--border-light);
}

.docs-lender-card img {
    max-height: clamp(24px, 1vw + 10px, 28px);
    max-width: clamp(80px, 3vw + 30px, 96px);
    object-fit: contain;
    filter: grayscale(1) opacity(0.55);
    transition: filter var(--dur-state) var(--ease-state);
}

a.docs-lender-card:hover img {
    filter: grayscale(0) opacity(1);
}

a.docs-lender-card:active {
    background: var(--border-light);
}

a.docs-lender-card:active img {
    filter: grayscale(0) opacity(1);
}

.docs-lender-card span {
    font-size: clamp(10px, 0.4vw + 4px, 11px);
    color: var(--text-tertiary);
}

@media (max-width: 900px) {
    .docs {
        grid-template-columns: 1fr;
        gap: 32px;
        padding: 96px 24px 60px;
    }
    .docs-side {
        position: static;
    }
    .docs-side-links {
        flex-direction: row;
        gap: 20px;
        overflow-x: auto;
        padding-bottom: 8px;
        border-bottom: 1px solid var(--border-light);
    }
    .docs-anatomy { grid-template-columns: 1fr 1fr; gap: 16px; }
    .docs-query { grid-template-columns: 1fr; gap: 12px; }
    .docs-provenance-row { grid-template-columns: 1fr; gap: 8px; }
    .docs-lender-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 640px) {
    .docs {
        padding: 88px 20px 56px;
        gap: 32px;
    }

    /* Section nav becomes a sticky chip row at the top of the viewport. */
    .docs-side {
        position: sticky;
        top: 0;
        z-index: 5;
        background: var(--bg);
        margin: 0 -20px; /* bleed to viewport edges so the chip row spans full width */
        padding: 12px 20px;
        border-bottom: 1px solid var(--border-light);
    }

    .docs-side-links {
        gap: 20px;
        padding-bottom: 0;
        border-bottom: none; /* moved to .docs-side above */
    }

    .docs-side-links a {
        /* Text-only — borders would read as chrome against the rest of the site. */
        padding: 4px 0;
        line-height: 1;
        white-space: nowrap;
    }

    /* Active chip: color differentiation only, matches the base .docs-side-links a.active rule. */

    /* Display headline less constrained on narrow viewports. */
    .docs-display {
        max-width: none;
    }

    /* Anatomy: 2-col at 900px → single-col stack on phones. */
    .docs-anatomy {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    /* Tighter verdict row columns to fit narrow viewports. */
    .docs-verdict {
        grid-template-columns: 72px 1fr;
        gap: 12px;
        padding: 6px 8px;
    }

    /* Policy rows stack label above content. */
    .docs-policy-row {
        grid-template-columns: 1fr;
        gap: 4px;
        padding: 10px 0;
    }

    /* Value rows keep inline label but tighter. */
    .docs-value-row {
        grid-template-columns: 60px 1fr;
        gap: 12px;
    }

    /* Larger tap target for lender tabs. */
    .docs-lender-tab {
        padding: 12px 4px;
    }

    /* Tighter lender cards on phones. */
    a.docs-lender-card {
        padding: 16px 8px;
    }
}