:root {
    --bg: #f4f1ea;
    --bg-strong: #fffdfc;
    --bg-muted: #ece7da;
    --surface: rgba(255, 253, 252, 0.88);
    --surface-strong: #ffffff;
    --text: #16202f;
    --text-soft: #5f6673;
    --text-faint: #7b8190;
    --line: #d8d4cb;
    --primary: #173d8f;
    --primary-strong: #102e6c;
    --accent: #b76e3d;
    --accent-soft: #efe2d8;
    --shadow: 0 24px 80px rgba(22, 32, 47, 0.1);
    --shadow-soft: 0 18px 42px rgba(22, 32, 47, 0.08);
    --radius-xl: 32px;
    --radius-lg: 24px;
    --radius-md: 18px;
    --radius-sm: 12px;
    --max-width: 1180px;
    --nav-height: 88px;
    --transition: 180ms ease;
}

[data-theme="dark"] {
    --bg: #0f1520;
    --bg-strong: #151c28;
    --bg-muted: #1a2331;
    --surface: rgba(21, 28, 40, 0.88);
    --surface-strong: #182130;
    --text: #edf2fb;
    --text-soft: #c5cfde;
    --text-faint: #99a6bb;
    --line: #293447;
    --primary: #87a4e6;
    --primary-strong: #aac0f4;
    --accent: #d99265;
    --accent-soft: rgba(217, 146, 101, 0.14);
    --shadow: 0 24px 80px rgba(0, 0, 0, 0.35);
    --shadow-soft: 0 18px 42px rgba(0, 0, 0, 0.28);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: calc(var(--nav-height) + 24px);
}

main [id] {
    scroll-margin-top: calc(var(--nav-height) + 24px);
}

body {
    background:
        radial-gradient(circle at top right, rgba(135, 164, 230, 0.16), transparent 26%),
        radial-gradient(circle at left center, rgba(183, 110, 61, 0.12), transparent 24%),
        var(--bg);
    color: var(--text);
    font-family: "Source Serif 4", Georgia, serif;
    line-height: 1.65;
    min-height: 100vh;
    transition: background-color var(--transition), color var(--transition);
}

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

a {
    color: inherit;
    text-decoration: none;
}

button {
    color: inherit;
    font: inherit;
}

.container {
    margin: 0 auto;
    max-width: var(--max-width);
    padding: 0 24px;
}

.skip-link {
    background: var(--primary);
    border-radius: 999px;
    color: #fff;
    left: 16px;
    padding: 10px 16px;
    position: absolute;
    top: -80px;
    transition: top var(--transition);
    z-index: 1000;
}

.skip-link:focus {
    top: 16px;
}

.site-header {
    backdrop-filter: blur(14px);
    background: rgba(244, 241, 234, 0.8);
    border-bottom: 1px solid rgba(216, 212, 203, 0.8);
    position: sticky;
    top: 0;
    z-index: 100;
}

[data-theme="dark"] .site-header {
    background: rgba(15, 21, 32, 0.82);
    border-bottom-color: rgba(41, 52, 71, 0.85);
}

.nav-shell {
    align-items: center;
    display: flex;
    justify-content: space-between;
    min-height: var(--nav-height);
}

.brand-mark,
.nav-link,
.button,
.theme-toggle,
.proof-bar-item,
.card-links a,
.evidence-links a,
.contact-card,
.site-footer a {
    font-family: "IBM Plex Sans", Arial, sans-serif;
}

.brand-mark {
    font-size: 1rem;
    font-weight: 700;
    letter-spacing: 0.02em;
}

.site-nav {
    align-items: center;
    display: flex;
    gap: 18px;
    position: relative;
}

.nav-menu {
    align-items: center;
    display: flex;
    gap: 20px;
}

.nav-link {
    color: var(--text-soft);
    font-size: 0.94rem;
    font-weight: 500;
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--text);
}

.nav-link::after {
    background: var(--primary);
    border-radius: 999px;
    bottom: -10px;
    content: "";
    height: 2px;
    left: 0;
    opacity: 0;
    position: absolute;
    transform: scaleX(0.4);
    transform-origin: left;
    transition: opacity var(--transition), transform var(--transition);
    width: 100%;
}

.nav-link:hover::after,
.nav-link.active::after {
    opacity: 1;
    transform: scaleX(1);
}

.nav-toggle {
    background: transparent;
    border: 0;
    cursor: pointer;
    display: none;
    flex-direction: column;
    gap: 6px;
    padding: 8px;
}

.nav-toggle span {
    background: var(--text);
    border-radius: 999px;
    display: block;
    height: 2px;
    width: 24px;
}

.theme-toggle {
    background: transparent;
    border: 0;
    cursor: pointer;
    padding: 0;
}

.brand-mark:focus-visible,
.nav-link:focus-visible,
.nav-toggle:focus-visible,
.theme-toggle:focus-visible,
.button:focus-visible,
.proof-bar-item:focus-visible,
.card-links a:focus-visible,
.evidence-links a:focus-visible,
.contact-card:focus-visible,
.site-footer a:focus-visible {
    outline: 3px solid var(--accent);
    outline-offset: 4px;
}

.theme-toggle-track {
    align-items: center;
    background: var(--bg-muted);
    border: 1px solid var(--line);
    border-radius: 999px;
    display: inline-flex;
    height: 34px;
    padding: 4px;
    position: relative;
    width: 62px;
}

.theme-toggle-thumb {
    background: var(--primary);
    border-radius: 999px;
    display: block;
    height: 24px;
    transform: translateX(0);
    transition: transform var(--transition), background-color var(--transition);
    width: 24px;
}

[data-theme="dark"] .theme-toggle-thumb {
    transform: translateX(28px);
}

.section-shell {
    padding: 84px 0;
}

.section-alt {
    background: linear-gradient(180deg, rgba(255, 253, 252, 0.25), rgba(236, 231, 218, 0.52));
}

[data-theme="dark"] .section-alt {
    background: linear-gradient(180deg, rgba(24, 33, 48, 0.42), rgba(17, 24, 36, 0.12));
}

.hero {
    padding-top: 52px;
}

.hero-grid {
    align-items: center;
    display: grid;
    gap: 32px;
    grid-template-columns: minmax(0, 1.2fr) minmax(320px, 0.8fr);
}

.eyebrow {
    color: var(--primary);
    font-family: "IBM Plex Sans", Arial, sans-serif;
    font-size: 0.82rem;
    font-weight: 700;
    letter-spacing: 0.14em;
    margin-bottom: 20px;
    text-transform: uppercase;
}

h1,
h2,
h3,
h4,
.proof-bar-item strong,
.fact-label,
.metric-label,
.contact-label {
    font-family: "IBM Plex Sans", Arial, sans-serif;
}

h1 {
    font-size: clamp(2.5rem, 4.6vw, 4.15rem);
    font-weight: 700;
    letter-spacing: -0.04em;
    line-height: 1.02;
    margin-bottom: 20px;
    max-width: 15ch;
}

h2 {
    font-size: clamp(2rem, 4vw, 3.15rem);
    font-weight: 700;
    letter-spacing: -0.03em;
    line-height: 1.06;
    margin-bottom: 14px;
}

h3 {
    font-size: clamp(1.2rem, 2vw, 1.55rem);
    font-weight: 700;
    letter-spacing: -0.02em;
    line-height: 1.18;
}

h4 {
    font-size: 1rem;
    font-weight: 700;
}

p {
    color: var(--text-soft);
}

.hero-lead {
    font-size: 1.18rem;
    margin-bottom: 18px;
    max-width: 60ch;
}

.hero-proof-line {
    color: var(--text);
    font-size: 1rem;
    margin-bottom: 18px;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    margin-bottom: 24px;
}

.button {
    align-items: center;
    border: 1px solid transparent;
    border-radius: 999px;
    display: inline-flex;
    font-size: 0.94rem;
    font-weight: 600;
    gap: 10px;
    justify-content: center;
    min-height: 48px;
    padding: 0 22px;
    transition: transform var(--transition), border-color var(--transition), background-color var(--transition);
}

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

.button-primary {
    background: var(--primary);
    color: #fff;
}

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

.button-secondary {
    background: transparent;
    border-color: var(--line);
    color: var(--text);
}

.button-secondary:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.proof-chip-list,
.tag-list,
.snapshot-list,
.evidence-list {
    list-style: none;
}

.proof-chip-list {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.proof-chip {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 999px;
    color: var(--text);
    font-family: "IBM Plex Sans", Arial, sans-serif;
    font-size: 0.9rem;
    font-weight: 500;
    padding: 10px 14px;
}

.hero-visual {
    align-self: stretch;
}

.research-visual-card,
.feature-card,
.theme-card,
.evidence-panel,
.contact-card,
.tool-stack {
    background: var(--surface);
    border: 1px solid rgba(216, 212, 203, 0.9);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-soft);
}

[data-theme="dark"] .research-visual-card,
[data-theme="dark"] .feature-card,
[data-theme="dark"] .theme-card,
[data-theme="dark"] .evidence-panel,
[data-theme="dark"] .contact-card,
[data-theme="dark"] .tool-stack {
    border-color: rgba(41, 52, 71, 0.95);
}

.research-visual-card {
    overflow: hidden;
}

.research-visual-card img {
    aspect-ratio: 1 / 1;
    object-fit: cover;
    width: 100%;
}

.research-visual-card figcaption {
    color: var(--text-soft);
    font-family: "IBM Plex Sans", Arial, sans-serif;
    font-size: 0.9rem;
    line-height: 1.5;
    padding: 16px 18px 20px;
}

.proof-bar {
    padding-top: 0;
}

.proof-bar-grid {
    display: grid;
    gap: 16px;
    grid-template-columns: repeat(4, minmax(0, 1fr));
}

.proof-bar-item {
    background: var(--surface-strong);
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-soft);
    display: flex;
    flex-direction: column;
    gap: 6px;
    min-height: 116px;
    justify-content: center;
    padding: 20px 22px;
    transition: border-color var(--transition), transform var(--transition);
}

.proof-bar-item:hover {
    border-color: var(--primary);
    transform: translateY(-2px);
}

.proof-label {
    color: var(--text-soft);
    font-family: "IBM Plex Sans", Arial, sans-serif;
    font-size: 0.82rem;
    font-weight: 600;
    letter-spacing: 0.03em;
    text-transform: uppercase;
}

.section-heading {
    margin-bottom: 34px;
    max-width: 760px;
}

.section-heading.compact {
    margin-bottom: 0;
}

.section-heading p {
    font-size: 1.02rem;
}

.feature-grid,
.theme-grid,
.evidence-grid,
.contact-grid {
    display: grid;
    gap: 20px;
}

.feature-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
}

.feature-card {
    padding: 24px;
}

.card-kicker {
    color: var(--primary);
    font-family: "IBM Plex Sans", Arial, sans-serif;
    font-size: 0.84rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    margin-bottom: 14px;
    text-transform: uppercase;
}

.work-breakdown {
    display: grid;
    gap: 16px;
    margin: 18px 0 22px;
}

.work-breakdown dt {
    color: var(--text);
    font-family: "IBM Plex Sans", Arial, sans-serif;
    font-size: 0.86rem;
    font-weight: 700;
    margin-bottom: 4px;
    text-transform: uppercase;
}

.work-breakdown dd {
    color: var(--text-soft);
}

.card-links,
.evidence-links {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
}

.card-links a,
.evidence-links a {
    color: var(--primary);
    font-size: 0.92rem;
    font-weight: 600;
}

.theme-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    margin-bottom: 24px;
}

.theme-card,
.tool-stack,
.evidence-panel,
.contact-card {
    padding: 24px;
}

.theme-card p + .theme-meta {
    margin-top: 10px;
}

.theme-meta {
    color: var(--text);
    font-family: "IBM Plex Sans", Arial, sans-serif;
    font-size: 0.9rem;
}

.tag-list {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 16px;
}

.tag-list li {
    background: var(--surface-strong);
    border: 1px solid var(--line);
    border-radius: 999px;
    color: var(--text);
    font-family: "IBM Plex Sans", Arial, sans-serif;
    font-size: 0.88rem;
    padding: 10px 14px;
}

.split-section {
    align-items: start;
    display: grid;
    gap: 32px;
    grid-template-columns: minmax(0, 0.8fr) minmax(0, 1fr);
}

.body-copy p + p {
    margin-top: 16px;
}

.bio-facts {
    border-top: 1px solid var(--line);
    display: grid;
    gap: 18px;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    margin-top: 28px;
    padding-top: 20px;
}

.fact-label {
    color: var(--text-faint);
    display: block;
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    margin-bottom: 6px;
    text-transform: uppercase;
}

.timeline-list {
    display: grid;
    gap: 18px;
}

.timeline-item {
    border-bottom: 1px solid var(--line);
    display: grid;
    gap: 18px;
    grid-template-columns: 180px minmax(0, 1fr);
    padding: 0 0 18px;
}

.timeline-item:last-child {
    border-bottom: 0;
    padding-bottom: 0;
}

.timeline-year {
    color: var(--primary);
    font-family: "IBM Plex Sans", Arial, sans-serif;
    font-size: 0.9rem;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
}

.timeline-content p {
    margin-top: 8px;
}

.evidence-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.evidence-grid.secondary {
    margin-top: 20px;
}

.snapshot-list {
    display: grid;
    gap: 16px;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    margin: 20px 0;
}

.snapshot-list li {
    background: var(--surface-strong);
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    padding: 16px;
}

.metric-value {
    display: block;
    font-family: "IBM Plex Sans", Arial, sans-serif;
    font-size: 2.2rem;
    font-weight: 700;
    letter-spacing: -0.04em;
}

.metric-label {
    color: var(--text-soft);
    display: block;
    font-size: 0.88rem;
    font-weight: 600;
    margin-top: 6px;
}

.snapshot-note {
    font-size: 0.95rem;
    margin-bottom: 18px;
}

.evidence-list {
    display: grid;
    gap: 16px;
}

.evidence-list li {
    border-top: 1px solid var(--line);
    padding-top: 16px;
}

.evidence-list li:first-child {
    border-top: 0;
    padding-top: 0;
}

.evidence-list strong {
    color: var(--text);
    display: block;
    font-family: "IBM Plex Sans", Arial, sans-serif;
    font-size: 0.95rem;
    margin-bottom: 4px;
}

.evidence-list span {
    color: var(--text-soft);
}

.contact-shell {
    display: grid;
    gap: 28px;
}

.contact-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.contact-card {
    transition: border-color var(--transition), transform var(--transition);
}

.contact-card:hover {
    border-color: var(--primary);
    transform: translateY(-2px);
}

.contact-label {
    color: var(--text-faint);
    display: block;
    font-size: 0.82rem;
    font-weight: 700;
    letter-spacing: 0.04em;
    margin-bottom: 8px;
    text-transform: uppercase;
}

.site-footer {
    border-top: 1px solid var(--line);
    padding: 28px 0 40px;
}

.footer-shell {
    align-items: center;
    color: var(--text-faint);
    display: flex;
    font-family: "IBM Plex Sans", Arial, sans-serif;
    font-size: 0.88rem;
    justify-content: space-between;
    gap: 18px;
}

.reveal-on-scroll {
    opacity: 0;
    transform: translateY(18px);
    transition: opacity 420ms ease, transform 420ms ease;
}

.reveal-on-scroll.is-visible {
    opacity: 1;
    transform: translateY(0);
}

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

    *,
    *::before,
    *::after {
        animation: none !important;
        transition: none !important;
    }

    .reveal-on-scroll {
        opacity: 1;
        transform: none;
    }
}

@media (max-width: 1024px) {
    .hero-grid,
    .split-section,
    .feature-grid,
    .proof-bar-grid,
    .theme-grid,
    .evidence-grid,
    .contact-grid,
    .snapshot-list {
        grid-template-columns: 1fr;
    }

    .timeline-item {
        grid-template-columns: 1fr;
    }

    .bio-facts {
        grid-template-columns: 1fr;
    }

    h1 {
        max-width: 14ch;
    }
}

@media (max-width: 820px) {
    body.nav-open {
        overflow: hidden;
    }

    .section-shell {
        padding: 72px 0;
    }

    .site-nav {
        align-items: flex-end;
        flex-direction: column;
    }

    .nav-toggle {
        display: inline-flex;
    }

    .nav-menu {
        align-items: stretch;
        background: var(--surface-strong);
        border: 1px solid var(--line);
        border-radius: 20px;
        box-shadow: var(--shadow-soft);
        display: none;
        min-width: min(92vw, 280px);
        padding: 16px;
        position: absolute;
        right: 24px;
        top: calc(var(--nav-height) - 8px);
    }

    .nav-menu.is-open {
        display: grid;
        gap: 14px;
    }

    .nav-link::after {
        display: none;
    }

    .theme-toggle {
        margin-top: 4px;
    }

    .hero {
        padding-top: 24px;
    }

    .hero-actions {
        display: grid;
        gap: 10px;
        grid-template-columns: repeat(2, minmax(0, 1fr));
        margin-bottom: 18px;
        max-width: 520px;
    }

    .hero-actions .button {
        min-height: 46px;
        padding: 0 16px;
        width: 100%;
    }

    .proof-chip-list {
        display: grid;
        gap: 10px;
        grid-template-columns: repeat(2, minmax(0, 1fr));
        max-width: 520px;
    }

    .proof-chip {
        align-items: center;
        display: flex;
        min-height: 44px;
        width: 100%;
    }
}

@media (max-width: 640px) {
    .container {
        padding: 0 18px;
    }

    .section-shell {
        padding: 60px 0;
    }

    h1 {
        font-size: 2.2rem;
        max-width: none;
    }

    h2 {
        font-size: 1.9rem;
    }

    .hero-lead,
    .hero-proof-line,
    .section-heading p,
    .body-copy p {
        font-size: 1rem;
    }

    .card-links,
    .evidence-links,
    .tag-list {
        gap: 10px;
    }

    .hero-proof-line {
        margin-bottom: 14px;
    }

    .proof-chip-list {
        margin-bottom: 18px;
    }

    .button {
        min-height: 44px;
        padding: 0 14px;
    }

    .proof-chip,
    .tag-list li {
        width: 100%;
    }

    .proof-chip {
        font-size: 0.82rem;
        min-height: 44px;
        padding: 10px 12px;
    }

    .hero-visual {
        margin-top: 4px;
    }

    .research-visual-card figcaption,
    .proof-label,
    .theme-meta,
    .contact-label {
        font-size: 0.84rem;
    }

    .footer-shell {
        align-items: flex-start;
        flex-direction: column;
    }
}