:root {
    --paper: #f6f7f8;
    --surface: #ffffff;
    --surface-soft: #fafbfd;
    --ink: #162433;
    --muted: #566575;
    --line: #d4dde5;
    --brand: #1d4f74;
    --brand-deep: #183852;
    --accent: #7b6747;
    --focus: rgba(29, 79, 116, 0.22);
    --page-width: min(1160px, calc(100% - 32px));
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    background: var(--paper);
    color: var(--ink);
    font-family: "IBM Plex Sans", "Segoe UI", sans-serif;
    line-height: 1.7;
}

a {
    color: inherit;
}

.skip-link {
    position: absolute;
    left: 16px;
    top: -48px;
    padding: 10px 14px;
    background: var(--ink);
    color: #ffffff;
    text-decoration: none;
    z-index: 10;
}

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

.page-shell {
    width: var(--page-width);
    margin: 0 auto;
    padding: 24px 0 48px;
}

.site-header {
    background: var(--surface);
    border-top: 4px solid var(--brand);
    border-bottom: 1px solid var(--line);
}

.utility-bar {
    display: flex;
    justify-content: space-between;
    gap: 20px;
    align-items: center;
    padding: 18px 24px 14px;
}

.return-link,
.conference-note,
.eyebrow,
.kicker,
.label,
.meta-list span {
    font-family: "IBM Plex Mono", monospace;
    font-size: 0.8rem;
    letter-spacing: 0.06em;
    text-transform: uppercase;
}

.return-link {
    color: var(--brand);
    text-decoration: none;
}

.conference-note {
    margin: 0;
    color: var(--muted);
    text-align: right;
}

#menu {
    display: flex;
    flex-wrap: wrap;
    gap: 14px 18px;
    padding: 12px 24px 18px;
    border-top: 1px solid var(--line);
}

#menu a {
    color: var(--brand-deep);
    text-decoration: none;
    font-size: 0.97rem;
    border-bottom: 1px solid transparent;
    transition: border-color 0.18s ease, color 0.18s ease;
}

#menu a:hover,
#menu a:focus-visible,
.return-link:hover,
.return-link:focus-visible,
.link-list a:hover,
.link-list a:focus-visible,
.organizer a:hover,
.organizer a:focus-visible,
.inline-link:hover,
.inline-link:focus-visible {
    color: var(--ink);
    border-color: currentColor;
}

.hero {
    display: grid;
    grid-template-columns: minmax(0, 1.6fr) 320px;
    gap: 28px;
    padding: 28px 24px 30px;
    border-top: 1px solid var(--line);
}

.eyebrow,
.kicker,
.label {
    margin: 0 0 10px;
    color: var(--brand);
}

h1,
h2,
h3 {
    margin: 0;
    font-family: "Source Serif 4", Georgia, serif;
    font-weight: 700;
    letter-spacing: -0.02em;
}

h1 {
    font-size: clamp(2.4rem, 5vw, 4rem);
    line-height: 1.03;
}

.hero-subtitle {
    margin: 14px 0 16px;
    color: var(--brand-deep);
    font-size: clamp(1.15rem, 2vw, 1.45rem);
    font-weight: 600;
    line-height: 1.4;
    max-width: 30ch;
}

.hero-copy {
    margin: 0;
    max-width: 66ch;
    color: var(--muted);
    font-size: 1.06rem;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 24px;
}

.button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 44px;
    padding: 0 16px;
    text-decoration: none;
    font-weight: 600;
    border: 1px solid var(--brand);
    transition: background 0.18s ease, color 0.18s ease, border-color 0.18s ease;
}

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

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

.button.primary:hover,
.button.primary:focus-visible {
    background: var(--brand-deep);
}

.button.secondary:hover,
.button.secondary:focus-visible {
    background: var(--surface-soft);
    border-color: var(--brand);
}

.hero-aside {
    align-self: start;
    padding-left: 20px;
    border-left: 1px solid var(--line);
}

.hero-aside h2 {
    font-size: 1.3rem;
    margin-bottom: 14px;
}

.summary-list {
    margin: 0;
    display: grid;
    gap: 14px;
}

.summary-list div {
    padding-bottom: 14px;
    border-bottom: 1px solid var(--line);
}

.summary-list div:last-child {
    padding-bottom: 0;
    border-bottom: 0;
}

.summary-list dt {
    color: var(--muted);
    font-size: 0.9rem;
    margin-bottom: 3px;
}

.summary-list dd {
    margin: 0;
    font-weight: 600;
    line-height: 1.45;
}

.content-grid {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 280px;
    gap: 36px;
    margin-top: 24px;
}

.main-column {
    min-width: 0;
}

.section {
    padding: 26px 0 28px;
    border-top: 1px solid var(--line);
}

.section:first-child {
    padding-top: 0;
    border-top: 0;
}

.section-heading {
    margin-bottom: 18px;
}

.section-heading h2 {
    font-size: clamp(1.55rem, 3vw, 2.15rem);
    line-height: 1.15;
}

.copy-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 22px;
}

.copy-grid p,
.contact-note {
    margin: 0;
    color: var(--muted);
    font-size: 1.02rem;
}

.topic-groups {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px 26px;
}

.topic-group {
    padding-left: 16px;
    border-left: 2px solid var(--line);
}

.topic-group h3,
.submission-note h3,
.organizer h3,
.timeline-item h3,
.sidebar-block h2 {
    font-size: 1.14rem;
}

.topic-group h3,
.submission-note h3,
.organizer h3,
.timeline-item h3 {
    margin-bottom: 10px;
}

.topic-group ul,
.submission-note ul {
    margin: 0;
    padding-left: 18px;
}

.topic-group li,
.submission-note li,
.timeline-item p {
    color: var(--muted);
}

.topic-group li + li,
.submission-note li + li {
    margin-top: 6px;
}

.submission-layout {
    display: grid;
    grid-template-columns: minmax(0, 1.25fr) 300px;
    gap: 24px;
    align-items: start;
}

.submission-note,
.sidebar-block {
    background: var(--surface);
    border: 1px solid var(--line);
    padding: 18px;
}

.submission-note p {
    margin: 0 0 14px;
    color: var(--muted);
}

.inline-link,
.organizer a,
.meta-list a {
    color: var(--brand-deep);
    text-decoration: none;
    border-bottom: 1px solid transparent;
}

.timeline {
    border-top: 1px solid var(--line);
}

.timeline-item {
    display: grid;
    grid-template-columns: 220px minmax(0, 1fr);
    gap: 16px 24px;
    padding: 16px 0;
    border-bottom: 1px solid var(--line);
}

.timeline-item .label {
    margin: 0;
    align-self: start;
}

.timeline-item h3 {
    grid-column: 1;
    color: var(--brand-deep);
}

.timeline-item p:last-child {
    grid-column: 2;
    margin: 0;
}

.organizer-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px 24px;
}

.organizer {
    padding-top: 2px;
}

.organizer p {
    margin: 0;
    color: var(--muted);
}

.organizer p + p {
    margin-top: 6px;
}

.contact-note {
    margin-top: 16px;
}

.side-column {
    display: grid;
    gap: 18px;
    align-self: start;
    position: sticky;
    top: 16px;
}

.sidebar-block h2 {
    margin-bottom: 14px;
}

.link-list,
.meta-list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.link-list li + li,
.meta-list li + li {
    border-top: 1px solid var(--line);
}

.link-list a {
    display: block;
    padding: 10px 0;
    color: var(--brand-deep);
    text-decoration: none;
    border-bottom: 1px solid transparent;
}

.meta-list li {
    padding: 12px 0;
}

.meta-list span {
    display: block;
    color: var(--muted);
    margin-bottom: 5px;
}

.meta-list strong {
    line-height: 1.45;
}

.footer {
    margin: 24px 0 0;
    padding-top: 16px;
    border-top: 1px solid var(--line);
    color: var(--muted);
    font-size: 0.95rem;
}

a:focus-visible {
    outline: 3px solid var(--focus);
    outline-offset: 3px;
}

@media (max-width: 1024px) {
    .hero,
    .content-grid,
    .submission-layout {
        grid-template-columns: 1fr;
    }

    .hero-aside {
        padding-left: 0;
        padding-top: 18px;
        border-left: 0;
        border-top: 1px solid var(--line);
    }

    .side-column {
        position: static;
    }
}

@media (max-width: 760px) {
    .page-shell {
        width: min(100% - 20px, 1160px);
        padding-top: 18px;
    }

    .utility-bar {
        flex-direction: column;
        align-items: flex-start;
    }

    .conference-note {
        text-align: left;
    }

    #menu {
        overflow-x: auto;
        flex-wrap: nowrap;
        -webkit-overflow-scrolling: touch;
    }

    #menu a {
        white-space: nowrap;
    }

    .hero,
    .submission-note,
    .sidebar-block {
        padding-left: 18px;
        padding-right: 18px;
    }

    .copy-grid,
    .topic-groups,
    .organizer-grid,
    .timeline-item {
        grid-template-columns: 1fr;
    }

    .timeline-item h3,
    .timeline-item p:last-child {
        grid-column: auto;
    }

    .hero-actions {
        flex-direction: column;
    }

    .button {
        width: 100%;
    }
}

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