:root {
    --bg: #f6f7f9;
    --surface: #ffffff;
    --surface-soft: #eef2f6;
    --ink: #111827;
    --muted: #5f6b7a;
    --line: #d9e0e7;
    --line-strong: #bbc5d0;
    --accent: #255fd5;
    --accent-dark: #18469f;
    --accent-soft: #e8efff;
    --success: #17745b;
    --success-soft: #e5f6ef;
    --warning: #945d08;
    --warning-soft: #fff4dd;
    --radius: 18px;
    --shadow: 0 20px 50px rgba(18, 28, 45, 0.07);
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    color: var(--ink);
    background: var(--bg);
    line-height: 1.6;
    text-rendering: optimizeLegibility;
}

a {
    color: inherit;
}

img {
    display: block;
    max-width: 100%;
}

.shell {
    width: min(1180px, calc(100% - 40px));
    margin: 0 auto;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 20;
    background: rgba(246, 247, 249, 0.92);
    backdrop-filter: blur(14px);
    border-bottom: 1px solid rgba(217, 224, 231, 0.85);
}

.header-inner {
    min-height: 66px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    font-weight: 750;
    letter-spacing: -0.02em;
}

.brand-mark {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--accent);
    box-shadow: 0 0 0 6px var(--accent-soft);
}

.header-links,
.footer-inner div {
    display: flex;
    align-items: center;
    gap: 20px;
}

.header-links a,
.footer-inner a {
    color: var(--muted);
    text-decoration: none;
    font-size: 0.94rem;
}

.header-links a:hover,
.footer-inner a:hover {
    color: var(--ink);
}

.hero {
    padding: 92px 0 72px;
    display: grid;
    grid-template-columns: minmax(0, 1.55fr) minmax(280px, 0.7fr);
    gap: 72px;
    align-items: end;
}

.eyebrow-row {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap;
    margin-bottom: 22px;
}

.eyebrow,
.section-kicker,
.toc-label,
.artifact-type,
.status-card-kicker {
    font-size: 0.78rem;
    font-weight: 800;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--muted);
}

.status-pill {
    display: inline-flex;
    padding: 5px 10px;
    border-radius: 999px;
    background: var(--warning-soft);
    color: var(--warning);
    font-size: 0.78rem;
    font-weight: 750;
}

h1,
h2,
h3,
p {
    margin-top: 0;
}

h1 {
    max-width: 780px;
    margin-bottom: 22px;
    font-size: clamp(3rem, 7vw, 6.4rem);
    line-height: 0.97;
    letter-spacing: -0.065em;
    font-weight: 800;
}

.hero-lead {
    max-width: 760px;
    color: var(--muted);
    font-size: clamp(1.05rem, 2vw, 1.25rem);
}

blockquote {
    margin: 34px 0 0;
    max-width: 760px;
    padding: 20px 24px;
    border-left: 4px solid var(--accent);
    background: var(--surface);
    border-radius: 0 14px 14px 0;
    font-size: 1.08rem;
    font-weight: 650;
    box-shadow: 0 8px 28px rgba(18, 28, 45, 0.035);
}

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

.button {
    min-height: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 16px;
    border-radius: 10px;
    text-decoration: none;
    font-weight: 750;
    font-size: 0.92rem;
    transition: transform 150ms ease, border-color 150ms ease, background 150ms ease;
}

.button:hover {
    transform: translateY(-1px);
}

.button-primary {
    color: #fff;
    background: var(--accent);
    border: 1px solid var(--accent);
}

.button-primary:hover {
    background: var(--accent-dark);
}

.button-secondary {
    background: var(--surface);
    border: 1px solid var(--line-strong);
    color: var(--ink);
}

.status-card {
    background: #101722;
    color: #fff;
    padding: 30px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.status-card-kicker {
    color: #a9b7c8;
    margin-bottom: 22px;
}

.status-metric {
    display: grid;
    grid-template-columns: 52px 1fr;
    gap: 14px;
    align-items: baseline;
    padding: 16px 0;
    border-bottom: 1px solid rgba(255,255,255,0.12);
}

.status-metric strong {
    font-size: 2rem;
    line-height: 1;
}

.status-metric span {
    color: #c8d1dc;
    font-size: 0.92rem;
}

.status-card p {
    margin: 22px 0 0;
    color: #c8d1dc;
    font-size: 0.92rem;
}

.progress-band {
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
    background: var(--surface);
}

.progress-grid {
    display: grid;
    grid-template-columns: repeat(7, minmax(0, 1fr));
}

.progress-step {
    min-width: 0;
    padding: 22px 16px 22px 0;
    border-right: 1px solid var(--line);
    color: var(--muted);
}

.progress-step + .progress-step {
    padding-left: 16px;
}

.progress-step:last-child {
    border-right: 0;
}

.progress-step span,
.progress-step strong,
.progress-step small {
    display: block;
}

.progress-step span {
    margin-bottom: 8px;
    font-size: 0.72rem;
    font-weight: 800;
    letter-spacing: 0.08em;
}

.progress-step strong {
    color: var(--ink);
    font-size: 0.9rem;
    line-height: 1.3;
}

.progress-step small {
    margin-top: 4px;
    font-size: 0.76rem;
}

.progress-step.complete span,
.progress-step.complete small {
    color: var(--success);
}

.progress-step.active {
    background: linear-gradient(180deg, rgba(232,239,255,0.75), rgba(232,239,255,0));
}

.progress-step.active span,
.progress-step.active small {
    color: var(--accent);
}

.case-study-layout {
    display: grid;
    grid-template-columns: 210px minmax(0, 1fr);
    gap: 70px;
    padding-top: 84px;
    padding-bottom: 100px;
}

.toc {
    position: sticky;
    top: 96px;
    align-self: start;
    display: grid;
    gap: 8px;
}

.toc-label {
    margin-bottom: 8px;
}

.toc a {
    padding: 7px 0;
    color: var(--muted);
    text-decoration: none;
    font-size: 0.9rem;
}

.toc a:hover {
    color: var(--ink);
}

.case-content {
    min-width: 0;
}

.case-section {
    display: grid;
    grid-template-columns: 54px minmax(0, 1fr);
    gap: 22px;
    padding: 0 0 96px;
    margin-bottom: 96px;
    border-bottom: 1px solid var(--line);
    scroll-margin-top: 100px;
}

.case-section-last {
    margin-bottom: 0;
    border-bottom: 0;
    padding-bottom: 0;
}

.section-number {
    width: 44px;
    height: 44px;
    display: grid;
    place-items: center;
    border: 1px solid var(--line-strong);
    border-radius: 50%;
    color: var(--muted);
    font-size: 0.78rem;
    font-weight: 800;
}

.section-kicker {
    margin-bottom: 10px;
}

.section-copy h2 {
    max-width: 770px;
    margin-bottom: 18px;
    font-size: clamp(2rem, 4vw, 3.5rem);
    line-height: 1.06;
    letter-spacing: -0.045em;
}

.section-copy > p {
    max-width: 790px;
    color: var(--muted);
    font-size: 1.03rem;
}

.principle-callout,
.scope-note,
.coverage-callout {
    margin-top: 30px;
    padding: 24px;
    border-radius: 14px;
    background: var(--surface-soft);
    border: 1px solid var(--line);
}

.principle-callout strong,
.scope-note span {
    display: block;
    margin-bottom: 7px;
    font-size: 0.82rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.principle-callout p,
.scope-note p,
.coverage-callout p {
    margin: 0;
    color: var(--muted);
}

.scope-note {
    background: var(--warning-soft);
    border-color: #ecd9ad;
}

.scope-note span {
    color: var(--warning);
    font-weight: 800;
}

.artifact-card {
    margin-top: 34px;
    padding: 22px;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.artifact-card img {
    width: 100%;
    margin-top: 18px;
    border-radius: 10px;
    background: #fff;
}

.artifact-narrow img {
    max-height: 820px;
    object-fit: contain;
}

.artifact-heading {
    display: flex;
    align-items: end;
    justify-content: space-between;
    gap: 20px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--line);
}

.artifact-heading h3 {
    margin: 4px 0 0;
    font-size: 1.1rem;
}

.artifact-heading a {
    color: var(--accent);
    text-decoration: none;
    font-size: 0.88rem;
    font-weight: 700;
    white-space: nowrap;
}

.requirements-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 12px;
    margin-top: 34px;
}

.requirement {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 14px;
    overflow: clip;
}

.requirement summary {
    min-height: 64px;
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 15px 16px;
    cursor: pointer;
    list-style: none;
}

.requirement summary::-webkit-details-marker {
    display: none;
}

.requirement summary::after {
    content: "+";
    margin-left: auto;
    color: var(--muted);
    font-size: 1.25rem;
}

.requirement[open] summary::after {
    content: "–";
}

.requirement summary span,
.req-id {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 54px;
    padding: 5px 8px;
    border-radius: 8px;
    background: var(--accent-soft);
    color: var(--accent-dark);
    font-size: 0.76rem;
    font-weight: 800;
    letter-spacing: 0.03em;
}

.requirement summary strong {
    line-height: 1.25;
}

.requirement p {
    margin: 0;
    padding: 0 16px 14px;
    color: var(--muted);
    font-size: 0.9rem;
}

.requirement p + p {
    padding-top: 0;
}

.artifact-download {
    margin-top: 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
    padding: 18px 20px;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 14px;
}

.artifact-download strong,
.artifact-download span {
    display: block;
}

.artifact-download span {
    margin-top: 2px;
    color: var(--muted);
    font-size: 0.86rem;
}

.delivery-table-wrap {
    margin-top: 34px;
    overflow-x: auto;
    border: 1px solid var(--line);
    border-radius: 14px;
    background: var(--surface);
}

.delivery-table {
    width: 100%;
    min-width: 760px;
    border-collapse: collapse;
    font-size: 0.9rem;
}

.delivery-table th,
.delivery-table td {
    padding: 16px;
    text-align: left;
    vertical-align: top;
    border-bottom: 1px solid var(--line);
}

.delivery-table th {
    background: #f9fafb;
    color: var(--muted);
    font-size: 0.76rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.delivery-table tbody tr:last-child td {
    border-bottom: 0;
}

.delivery-table a {
    color: var(--accent);
    font-weight: 700;
}

.coverage-callout {
    display: grid;
    grid-template-columns: 180px 1fr;
    gap: 24px;
    align-items: center;
    background: var(--accent-soft);
    border-color: #c9d8ff;
}

.coverage-callout div strong,
.coverage-callout div span {
    display: block;
}

.coverage-callout div strong {
    font-size: 2rem;
    line-height: 1;
    color: var(--accent-dark);
}

.coverage-callout div span {
    margin-top: 6px;
    color: var(--accent-dark);
    font-size: 0.82rem;
    line-height: 1.3;
}

.next-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 14px;
    margin-top: 34px;
}

.next-card {
    min-height: 170px;
    padding: 22px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    gap: 36px;
    border-radius: 16px;
    background: var(--surface);
    border: 1px solid var(--line);
}

.next-card span {
    color: var(--muted);
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    font-weight: 800;
}

.next-card strong {
    line-height: 1.35;
}

.next-card.complete {
    border-color: #bfdfd4;
    background: var(--success-soft);
}

.next-card.complete span {
    color: var(--success);
}

.next-card.active {
    border-color: #c9d8ff;
    background: var(--accent-soft);
}

.next-card.active span {
    color: var(--accent-dark);
}

.closing-note {
    margin-top: 28px !important;
}

footer {
    border-top: 1px solid var(--line);
    background: var(--surface);
}

.footer-inner {
    min-height: 86px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
    color: var(--muted);
    font-size: 0.88rem;
}

@media (max-width: 980px) {
    .hero {
        grid-template-columns: 1fr;
        gap: 42px;
        padding-top: 70px;
    }

    .status-card {
        max-width: 620px;
    }

    .progress-grid {
        grid-template-columns: repeat(4, 1fr);
    }

    .progress-step:nth-child(4) {
        border-right: 0;
    }

    .progress-step:nth-child(n+5) {
        border-top: 1px solid var(--line);
    }

    .case-study-layout {
        grid-template-columns: 1fr;
        gap: 42px;
    }

    .toc {
        position: static;
        grid-template-columns: repeat(2, minmax(0, 1fr));
        gap: 4px 18px;
        padding: 18px 0;
        border-top: 1px solid var(--line);
        border-bottom: 1px solid var(--line);
    }

    .toc-label {
        grid-column: 1 / -1;
    }
}

@media (max-width: 720px) {
    .shell {
        width: min(100% - 28px, 1180px);
    }

    .header-inner {
        min-height: 60px;
    }

    .header-links {
        gap: 12px;
    }

    .header-links a:first-child {
        display: none;
    }

    .hero {
        padding: 54px 0 48px;
    }

    h1 {
        font-size: clamp(2.8rem, 15vw, 4.8rem);
    }

    blockquote {
        padding: 18px;
    }

    .progress-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .progress-step,
    .progress-step + .progress-step {
        padding: 18px 12px;
        border-right: 1px solid var(--line);
        border-top: 1px solid var(--line);
    }

    .progress-step:nth-child(odd) {
        border-left: 0;
    }

    .progress-step:nth-child(even) {
        border-right: 0;
    }

    .case-study-layout {
        padding-top: 54px;
        padding-bottom: 70px;
    }

    .toc {
        grid-template-columns: 1fr;
    }

    .case-section {
        grid-template-columns: 1fr;
        gap: 18px;
        padding-bottom: 70px;
        margin-bottom: 70px;
    }

    .section-number {
        width: 38px;
        height: 38px;
    }

    .requirements-grid,
    .next-grid {
        grid-template-columns: 1fr;
    }

    .artifact-heading,
    .artifact-download,
    .footer-inner {
        align-items: flex-start;
        flex-direction: column;
    }

    .artifact-heading a {
        white-space: normal;
    }

    .coverage-callout {
        grid-template-columns: 1fr;
    }

    .footer-inner {
        padding: 22px 0;
    }
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    .button {
        transition: none;
    }
}