/* ============================================================================
 * pm-b3-tracer.css
 *
 * Sprint 6 task 5 — Walk-to-b3 widget.
 *
 * Styles the modal overlay and SVG dependency graph used to trace any
 * formula back to the Sprint 3.4 / 3.5 root seed b3 = 24. Two side-by-side
 * columns: Arithma symbolic chain (left) and EML op-token chain (right).
 *
 * No external CSS framework. Uses the same CSS custom properties that
 * `pm-common.css` / `pm-glass-theme.css` define so the modal blends with
 * the rest of the site.
 * ============================================================================ */

/* Modal scaffolding ---------------------------------------------------------*/
.pm-b3-modal {
    position: fixed;
    inset: 0;
    z-index: 9000;
    display: none;
    align-items: center;
    justify-content: center;
    padding: 1.5rem;
}

.pm-b3-modal.is-open {
    display: flex;
}

.pm-b3-modal__overlay {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.78);
    backdrop-filter: blur(6px);
    cursor: pointer;
}

.pm-b3-modal__panel {
    position: relative;
    z-index: 1;
    width: min(1100px, 100%);
    max-height: 90vh;
    background: var(--bg-card, #1a1a2e);
    border: 1px solid var(--border-primary, rgba(139, 127, 255, 0.32));
    border-radius: 14px;
    box-shadow: 0 24px 60px rgba(0, 0, 0, 0.55);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.pm-b3-modal__header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 1rem;
    padding: 1rem 1.25rem 0.75rem;
    border-bottom: 1px solid var(--border-secondary, rgba(255, 255, 255, 0.08));
}

.pm-b3-modal__title {
    margin: 0;
    font-family: 'Crimson Text', Georgia, serif;
    font-size: 1.35rem;
    color: var(--text-primary, #e0e0e0);
}

.pm-b3-modal__subtitle {
    margin: 0.15rem 0 0 0;
    font-size: 0.85rem;
    color: var(--text-muted, #888);
}

.pm-b3-modal__close {
    background: transparent;
    border: 1px solid var(--border-secondary, rgba(255, 255, 255, 0.18));
    color: var(--text-primary, #e0e0e0);
    border-radius: 8px;
    width: 36px;
    height: 36px;
    font-size: 1.1rem;
    cursor: pointer;
    flex: 0 0 auto;
}

.pm-b3-modal__close:hover {
    background: rgba(255, 255, 255, 0.05);
    color: var(--accent-secondary, #ff7eb6);
}

.pm-b3-modal__body {
    flex: 1 1 auto;
    overflow-y: auto;
    padding: 1rem 1.25rem;
}

.pm-b3-modal__footer {
    border-top: 1px solid var(--border-secondary, rgba(255, 255, 255, 0.08));
    padding: 0.75rem 1.25rem;
    font-size: 0.85rem;
    color: var(--text-secondary, #b0b0b0);
    background: rgba(0, 0, 0, 0.2);
}

/* Two-column layout ---------------------------------------------------------*/
.pm-b3-cols {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

@media (max-width: 760px) {
    .pm-b3-cols {
        grid-template-columns: 1fr;
    }
}

.pm-b3-col {
    background: rgba(0, 0, 0, 0.18);
    border: 1px solid var(--border-secondary, rgba(255, 255, 255, 0.08));
    border-radius: 10px;
    padding: 0.75rem;
    display: flex;
    flex-direction: column;
    min-height: 320px;
}

.pm-b3-col__head {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.pm-b3-col__title {
    margin: 0;
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--accent-primary, #8b7fff);
    letter-spacing: 0.02em;
}

.pm-b3-col__meta {
    font-size: 0.75rem;
    color: var(--text-muted, #888);
}

.pm-b3-col__svg {
    flex: 1 1 auto;
    width: 100%;
    height: auto;
    min-height: 280px;
    background: rgba(255, 255, 255, 0.02);
    border-radius: 8px;
}

.pm-b3-col__empty {
    color: var(--text-muted, #888);
    font-style: italic;
    padding: 1rem;
    text-align: center;
}

/* SVG node styling ----------------------------------------------------------*/
.pm-b3-node rect {
    fill: var(--bg-secondary, #16172e);
    stroke: var(--accent-primary, #8b7fff);
    stroke-width: 1.4;
    rx: 6;
    ry: 6;
}

.pm-b3-node--root rect {
    fill: rgba(139, 127, 255, 0.18);
    stroke: var(--accent-primary, #8b7fff);
    stroke-width: 2;
}

.pm-b3-node--b3 rect {
    fill: rgba(81, 207, 102, 0.18);
    stroke: var(--accent-success, #51cf66);
    stroke-width: 2.4;
}

.pm-b3-node--op rect {
    fill: rgba(79, 172, 254, 0.10);
    stroke: var(--accent-info, #4facfe);
    stroke-dasharray: 4 3;
    stroke-width: 1.1;
}

.pm-b3-node text {
    fill: var(--text-primary, #e0e0e0);
    font-family: 'Source Code Pro', 'Menlo', monospace;
    font-size: 12px;
    text-anchor: middle;
    dominant-baseline: middle;
    pointer-events: none;
}

.pm-b3-node--b3 text.pm-b3-label {
    fill: var(--accent-success, #51cf66);
    font-weight: 700;
}

.pm-b3-node text.pm-b3-sub {
    fill: var(--text-muted, #888);
    font-size: 10px;
}

.pm-b3-edge {
    stroke: var(--text-muted, #888);
    stroke-width: 1.2;
    fill: none;
    marker-end: url(#pm-b3-arrow);
}

.pm-b3-edge--via text {
    fill: var(--text-secondary, #b0b0b0);
    font-family: 'Source Code Pro', monospace;
    font-size: 10px;
}

/* Foundations-page demo panel ----------------------------------------------*/
.pm-b3-demo {
    margin: 2rem 0;
    padding: 1.25rem 1.5rem;
    background: linear-gradient(135deg,
        rgba(139, 127, 255, 0.10),
        rgba(255, 126, 182, 0.06));
    border: 1px solid var(--border-primary, rgba(139, 127, 255, 0.32));
    border-radius: 12px;
}

.pm-b3-demo__title {
    margin: 0 0 0.35rem 0;
    font-family: 'Crimson Text', Georgia, serif;
    font-size: 1.4rem;
    color: var(--text-primary, #e0e0e0);
}

.pm-b3-demo__lede {
    margin: 0 0 1rem 0;
    color: var(--text-secondary, #b0b0b0);
    font-size: 0.95rem;
}

.pm-b3-demo__grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 0.75rem;
}

.pm-b3-demo__card {
    background: rgba(0, 0, 0, 0.25);
    border: 1px solid var(--border-secondary, rgba(255, 255, 255, 0.08));
    border-radius: 10px;
    padding: 0.85rem 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.45rem;
}

.pm-b3-demo__label {
    font-family: 'Source Code Pro', monospace;
    font-size: 0.78rem;
    color: var(--text-muted, #888);
    letter-spacing: 0.03em;
}

.pm-b3-demo__name {
    font-size: 1.05rem;
    color: var(--text-primary, #e0e0e0);
    font-weight: 600;
}

.pm-b3-demo__desc {
    font-size: 0.85rem;
    color: var(--text-secondary, #b0b0b0);
    line-height: 1.4;
    flex: 1 1 auto;
}

.pm-b3-demo__btn {
    align-self: flex-start;
    background: var(--accent-primary, #8b7fff);
    color: #fff;
    border: none;
    border-radius: 6px;
    padding: 0.4rem 0.85rem;
    font-size: 0.85rem;
    cursor: pointer;
    font-family: inherit;
}

.pm-b3-demo__btn:hover {
    background: var(--accent-secondary, #ff7eb6);
}