/* Engineering portfolio layer: technical field-notebook, shared by new pages. */

body.engineering-site {
    --eng-bg: #f4f8fa;
    --eng-ink: #102b3a;
    --eng-muted: #4d6876;
    --eng-blue: #087ea4;
    --eng-teal: #0f8f83;
    --eng-coral: #d85d3f;
    --eng-line: rgba(16, 43, 58, 0.16);
    --eng-soft: rgba(8, 126, 164, 0.08);
    --eng-dark: #0c2635;
    background: var(--eng-bg);
    background-image:
        linear-gradient(rgba(16, 43, 58, 0.035) 1px, transparent 1px),
        linear-gradient(90deg, rgba(16, 43, 58, 0.035) 1px, transparent 1px),
        radial-gradient(circle at 88% 8%, rgba(216, 93, 63, 0.12), transparent 28rem);
    background-size: 28px 28px, 28px 28px, auto;
    color: var(--eng-ink);
}

.engineering-site #fun-canvas,
.engineering-site .aurora,
.engineering-site::after { display: none; }

.engineering-site header.scrolled {
    background: rgba(244, 248, 250, 0.94);
    border-bottom-color: var(--eng-line);
}

.engineering-site .nav-menu a.active {
    background: var(--eng-ink);
    color: #fff;
    box-shadow: none;
}

.engineering-site .nav-menu a:hover {
    background: var(--eng-soft);
    color: var(--eng-ink);
}

.engineering-site .logo { color: var(--eng-ink); }

.engineering-site .logo .dot { color: var(--eng-coral); background: none; }

.engineering-site main,
.engineering-site section { position: relative; z-index: 2; }

.systems-hero {
    padding: 132px 0 56px;
    min-height: 700px;
    display: flex;
    align-items: center;
}

.systems-hero-grid {
    display: grid;
    grid-template-columns: minmax(0, 1.02fr) minmax(420px, 0.98fr);
    align-items: center;
    gap: 68px;
}

.systems-hero h1,
.case-hero h1,
.systems-index-hero h1 {
    font-family: var(--font-heading);
    color: var(--eng-ink);
    font-weight: 600;
    letter-spacing: -0.045em;
    line-height: 0.98;
}

.systems-hero h1 { font-size: clamp(3.3rem, 7.2vw, 6.25rem); max-width: 11ch; }

.hero-positioning {
    margin: 28px 0 0;
    max-width: 58ch;
    font-size: clamp(1.05rem, 1.7vw, 1.32rem);
    line-height: 1.55;
    color: var(--eng-muted);
}

.hero-positioning strong { color: var(--eng-ink); }

.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 30px; }

.engineering-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 9px;
    min-height: 46px;
    padding: 0 18px;
    border: 1px solid var(--eng-ink);
    border-radius: 4px;
    color: var(--eng-ink);
    font-weight: 700;
    font-size: 0.94rem;
}

.engineering-button.primary { background: var(--eng-ink); color: #fff; }
.engineering-button:hover { color: var(--eng-coral); border-color: var(--eng-coral); }
.engineering-button.primary:hover { color: #fff; background: var(--eng-coral); }

.role-line {
    display: flex;
    flex-wrap: wrap;
    gap: 10px 24px;
    margin-top: 28px;
    color: var(--eng-muted);
    font-family: var(--font-mono);
    font-size: 0.78rem;
}

.system-map {
    position: relative;
    overflow: hidden;
    border-radius: 8px;
    background: var(--eng-dark);
    color: #eaf7fb;
    padding: 26px;
    box-shadow: 18px 22px 0 rgba(8, 126, 164, 0.12);
}

.system-map::after {
    content: "";
    position: absolute;
    inset: 0;
    pointer-events: none;
    background-image: linear-gradient(rgba(234, 247, 251, 0.04) 1px, transparent 1px);
    background-size: 100% 34px;
}

.system-map-head,
.system-map-foot {
    position: relative;
    z-index: 1;
    display: flex;
    justify-content: space-between;
    gap: 20px;
    font-family: var(--font-mono);
    font-size: 0.7rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: #8ac9dc;
}

.system-map-flow { position: relative; z-index: 1; margin: 28px 0; }

.map-node {
    display: grid;
    grid-template-columns: 28px 1fr auto;
    gap: 12px;
    align-items: center;
    border-top: 1px solid rgba(234, 247, 251, 0.18);
    padding: 14px 0;
}

.map-node:last-child { border-bottom: 1px solid rgba(234, 247, 251, 0.18); }
.map-index { font-family: var(--font-mono); color: #f09274; font-size: 0.72rem; }
.map-node strong { font-size: 0.95rem; }
.map-node span:last-child { font-family: var(--font-mono); color: #95b5c1; font-size: 0.7rem; text-align: right; }

.metric-rail {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    border-block: 1px solid var(--eng-line);
    background: rgba(244, 248, 250, 0.86);
}

.metric-item { padding: 25px 24px; border-right: 1px solid var(--eng-line); }
.metric-item:last-child { border-right: 0; }
.metric-item strong { display: block; font-family: var(--font-heading); font-size: clamp(1.75rem, 3vw, 2.6rem); line-height: 1; color: var(--eng-blue); }
.metric-item span { display: block; margin-top: 7px; font-family: var(--font-mono); font-size: 0.72rem; line-height: 1.45; color: var(--eng-muted); }

.engineering-section { padding: 100px 0; }
.engineering-section.compact { padding: 70px 0; }
.section-rule { border-top: 1px solid var(--eng-line); padding-top: 24px; }
.section-number { font-family: var(--font-mono); color: var(--eng-coral); font-size: 0.78rem; }
.engineering-section h2 {
    font-family: var(--font-heading);
    font-size: clamp(2.25rem, 5vw, 4.4rem);
    line-height: 1.02;
    letter-spacing: -0.035em;
    max-width: 14ch;
    margin-top: 10px;
}
.section-intro { max-width: 62ch; color: var(--eng-muted); margin-top: 18px; font-size: 1.03rem; }

.flagship-layout {
    display: grid;
    grid-template-columns: minmax(0, 0.85fr) minmax(480px, 1.15fr);
    gap: 64px;
    margin-top: 48px;
    align-items: start;
}

.flagship-copy h3 { font-family: var(--font-heading); font-size: 2.25rem; line-height: 1.08; }
.flagship-copy p { color: var(--eng-muted); margin-top: 18px; }
.constraint-line { margin-top: 24px; border-left: 3px solid var(--eng-coral); padding-left: 16px; color: var(--eng-ink) !important; }
.stack-line { margin-top: 24px; font-family: var(--font-mono); font-size: 0.74rem; line-height: 1.8; color: var(--eng-teal); }
.text-link { display: inline-flex; gap: 8px; align-items: center; margin-top: 24px; font-weight: 700; color: var(--eng-blue); }
.text-link:hover { color: var(--eng-coral); }

.pipeline-diagram {
    display: grid;
    grid-template-columns: repeat(5, minmax(0, 1fr));
    border: 1px solid var(--eng-line);
    background: rgba(255, 255, 255, 0.68);
}

.pipeline-step { position: relative; min-height: 172px; padding: 18px 16px; border-right: 1px solid var(--eng-line); }
.pipeline-step:last-child { border-right: 0; }
.pipeline-step::after { content: "→"; position: absolute; right: -9px; top: 48%; z-index: 2; color: var(--eng-coral); background: var(--eng-bg); font-weight: 800; }
.pipeline-step:last-child::after { display: none; }
.pipeline-step small { font-family: var(--font-mono); color: var(--eng-coral); }
.pipeline-step strong { display: block; margin-top: 22px; font-size: 0.95rem; line-height: 1.25; }
.pipeline-step span { display: block; margin-top: 9px; color: var(--eng-muted); font-size: 0.78rem; line-height: 1.45; }

.system-list { margin-top: 44px; border-top: 1px solid var(--eng-line); }
.system-row {
    display: grid;
    grid-template-columns: 64px minmax(250px, 0.75fr) minmax(0, 1.25fr) auto;
    gap: 28px;
    align-items: start;
    padding: 30px 0;
    border-bottom: 1px solid var(--eng-line);
}
.system-row-index { font-family: var(--font-mono); color: var(--eng-coral); }
.system-row h3 { font-family: var(--font-heading); font-size: 1.55rem; line-height: 1.1; }
.system-row p { color: var(--eng-muted); font-size: 0.94rem; }
.system-row-meta { margin-top: 10px; font-family: var(--font-mono); font-size: 0.68rem; color: var(--eng-teal); line-height: 1.55; }
.system-row-links { display: flex; flex-direction: column; gap: 8px; min-width: 92px; font-size: 0.82rem; font-weight: 700; text-align: right; }

.principles-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0; margin-top: 44px; border: 1px solid var(--eng-line); }
.principle { padding: 28px; border-right: 1px solid var(--eng-line); background: rgba(255,255,255,0.56); }
.principle:last-child { border-right: 0; }
.principle code { color: var(--eng-coral); font-family: var(--font-mono); }
.principle h3 { margin-top: 26px; font-family: var(--font-heading); font-size: 1.45rem; }
.principle p { margin-top: 12px; color: var(--eng-muted); font-size: 0.92rem; }

.engineering-footer { border-top: 1px solid var(--eng-line); background: var(--eng-dark); color: #dcebf0; }
.engineering-footer .footer-logo { color: #fff; }
.engineering-footer p { color: #9db3bd; }
.engineering-footer a { color: #9cd8e6; }

/* Systems index */
.systems-index-hero { padding: 160px 0 56px; }
.systems-index-hero h1 { font-size: clamp(3rem, 7vw, 5.6rem); max-width: 13ch; }
.systems-index-hero p { max-width: 65ch; margin-top: 22px; color: var(--eng-muted); font-size: 1.08rem; }
.system-index-group { padding: 70px 0; border-top: 1px solid var(--eng-line); }
.system-index-group h2 { font-family: var(--font-heading); font-size: 2.2rem; }
.archive-links { display: flex; flex-wrap: wrap; gap: 12px 24px; margin-top: 24px; }
.archive-links a { border-bottom: 1px solid var(--eng-line); padding-bottom: 4px; }

/* Case studies */
.case-hero { padding: 158px 0 62px; border-bottom: 1px solid var(--eng-line); }
.case-hero h1 { font-size: clamp(3rem, 7vw, 5.75rem); max-width: 13ch; }
.case-summary { max-width: 72ch; margin-top: 26px; color: var(--eng-muted); font-size: 1.12rem; }
.case-kicker { font-family: var(--font-mono); color: var(--eng-coral); font-size: 0.76rem; letter-spacing: 0.08em; text-transform: uppercase; }
.case-actions { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 28px; }
.case-metrics { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; margin-top: 48px; background: var(--eng-line); border: 1px solid var(--eng-line); }
.case-metric { background: var(--eng-bg); padding: 20px; }
.case-metric strong { display: block; color: var(--eng-blue); font-family: var(--font-heading); font-size: 2rem; }
.case-metric span { display: block; margin-top: 4px; color: var(--eng-muted); font-family: var(--font-mono); font-size: 0.69rem; }

.article-shell { display: grid; grid-template-columns: 210px minmax(0, 760px); gap: 72px; align-items: start; padding: 72px 0 110px; }
.case-nav { position: sticky; top: 100px; border-top: 2px solid var(--eng-ink); padding-top: 16px; }
.case-nav strong { font-family: var(--font-mono); font-size: 0.72rem; text-transform: uppercase; }
.case-nav a { display: block; padding: 7px 0; color: var(--eng-muted); font-size: 0.8rem; }
.case-nav a:hover { color: var(--eng-coral); }
.case-content { min-width: 0; }
.case-section { scroll-margin-top: 95px; padding: 0 0 54px; margin-bottom: 54px; border-bottom: 1px solid var(--eng-line); }
.case-section:last-child { border-bottom: 0; margin-bottom: 0; }
.case-section h2 { font-family: var(--font-heading); font-size: clamp(2rem, 4vw, 3rem); line-height: 1.08; letter-spacing: -0.025em; }
.case-section h3 { font-family: var(--font-heading); font-size: 1.4rem; margin-top: 34px; }
.case-section p { margin-top: 16px; color: var(--eng-muted); }
.case-section ul { margin-top: 18px; color: var(--eng-muted); }
.case-section li { margin-bottom: 9px; padding-left: 4px; }
.case-section strong { color: var(--eng-ink); }

.constraint-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1px; margin-top: 26px; background: var(--eng-line); border: 1px solid var(--eng-line); }
.constraint { background: var(--eng-bg); padding: 22px; }
.constraint small { font-family: var(--font-mono); color: var(--eng-coral); }
.constraint h3 { margin-top: 14px; font-size: 1.15rem; }
.constraint p { font-size: 0.88rem; margin-top: 9px; }

.architecture-stack { margin-top: 28px; border: 1px solid var(--eng-line); }
.architecture-layer { display: grid; grid-template-columns: 140px 1fr; gap: 20px; padding: 18px 20px; border-bottom: 1px solid var(--eng-line); background: rgba(255,255,255,0.62); }
.architecture-layer:last-child { border-bottom: 0; }
.architecture-layer code { font-family: var(--font-mono); color: var(--eng-coral); font-size: 0.74rem; }
.architecture-layer p { margin: 0; font-size: 0.9rem; }

.decision-table-wrap { overflow-x: auto; margin-top: 26px; border: 1px solid var(--eng-line); }
.decision-table { width: 100%; min-width: 680px; border-collapse: collapse; background: rgba(255,255,255,0.6); }
.decision-table th,
.decision-table td { text-align: left; vertical-align: top; padding: 15px; border-bottom: 1px solid var(--eng-line); font-size: 0.85rem; }
.decision-table th { font-family: var(--font-mono); font-size: 0.68rem; text-transform: uppercase; color: var(--eng-blue); }
.decision-table tr:last-child td { border-bottom: 0; }
.decision-table td:first-child { font-weight: 700; color: var(--eng-ink); }

.code-window { margin-top: 26px; border-radius: 6px; overflow: hidden; background: var(--eng-dark); color: #dcebf0; }
.code-window-head { display: flex; justify-content: space-between; padding: 10px 14px; border-bottom: 1px solid rgba(255,255,255,0.12); font-family: var(--font-mono); font-size: 0.68rem; color: #8ac9dc; }
.code-window pre { overflow-x: auto; padding: 18px; font-size: 0.75rem; line-height: 1.7; }
.code-window code { font-family: var(--font-mono); }

.callout { margin-top: 26px; padding: 22px; border-left: 4px solid var(--eng-coral); background: rgba(216, 93, 63, 0.07); }
.callout p { margin: 0; color: var(--eng-ink); }
.ops-figure { margin-top: 28px; padding: 18px; border: 1px solid var(--eng-line); background: #fff; }
.ops-figure img { width: 100%; }
.ops-figure figcaption { margin-top: 10px; color: var(--eng-muted); font-size: 0.78rem; }
.ownership-note { margin-top: 26px; font-size: 0.86rem; color: var(--eng-muted); }

@media (max-width: 980px) {
    .systems-hero { min-height: auto; }
    .systems-hero-grid,
    .flagship-layout { grid-template-columns: 1fr; }
    .systems-hero-grid { gap: 46px; }
    .system-map { max-width: 680px; }
    .system-row { grid-template-columns: 48px 1fr; }
    .system-row p,
    .system-row-links { grid-column: 2; text-align: left; }
    .system-row-links { flex-direction: row; }
    .article-shell { grid-template-columns: 1fr; gap: 38px; }
    .case-nav { position: static; display: flex; flex-wrap: wrap; gap: 0 18px; }
    .case-nav strong { flex-basis: 100%; margin-bottom: 8px; }
}

@media (max-width: 760px) {
    .systems-hero { padding: 122px 0 54px; }
    .systems-hero-grid { grid-template-columns: minmax(0, 1fr); }
    .systems-hero h1 { font-size: clamp(3rem, 15vw, 4.6rem); }
    .system-map { padding: 20px; box-shadow: 10px 12px 0 rgba(8,126,164,0.12); }
    .metric-rail,
    .case-metrics { grid-template-columns: repeat(2, 1fr); }
    .metric-item:nth-child(2) { border-right: 0; }
    .metric-item:nth-child(-n+2) { border-bottom: 1px solid var(--eng-line); }
    .pipeline-diagram { grid-template-columns: 1fr; }
    .pipeline-step { min-height: 0; border-right: 0; border-bottom: 1px solid var(--eng-line); }
    .pipeline-step::after { content: "↓"; top: auto; right: 18px; bottom: -13px; }
    .pipeline-step:last-child { border-bottom: 0; }
    .principles-grid,
    .constraint-grid { grid-template-columns: 1fr; }
    .principle { border-right: 0; border-bottom: 1px solid var(--eng-line); }
    .principle:last-child { border-bottom: 0; }
    .case-hero { padding-top: 128px; }
    .case-hero h1 { font-size: clamp(2.8rem, 14vw, 4.5rem); }
    .article-shell { padding-top: 48px; }
    .architecture-layer { grid-template-columns: 1fr; gap: 8px; }
}

@media (max-width: 520px) {
    .metric-rail,
    .case-metrics { grid-template-columns: 1fr; }
    .metric-item { border-right: 0; border-bottom: 1px solid var(--eng-line); }
    .metric-item:last-child { border-bottom: 0; }
    .system-row { grid-template-columns: 34px 1fr; gap: 14px; }
    .system-map-head,
    .system-map-foot { flex-direction: column; gap: 4px; }
    .map-node { grid-template-columns: 24px 1fr; }
    .map-node span:last-child { grid-column: 2; text-align: left; }
}

@media (prefers-reduced-motion: reduce) {
    .engineering-site * { animation: none !important; transition-duration: 0.01ms !important; }
}