/* Navigation and sections for the Systems, Projects and Demonstrations indexes. */
.directory-rail {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    border: 1px solid var(--line);
    border-top: 0;
    border-radius: 0 0 8px 8px;
    background: var(--paper);
    box-shadow: 0 8px 22px #1522360c;
}
.directory-rail a {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 3px 12px;
    align-content: start;
    min-width: 0;
    padding: 20px clamp(16px, 2.2vw, 28px);
}
.directory-rail a + a { border-left: 1px solid var(--line); }
.directory-rail a:hover { background: var(--soft); }
.directory-rail strong { font-size: clamp(16px, 1.8vw, 21px); line-height: 1.2; letter-spacing: -.02em; }
.directory-rail small { grid-column: 1; color: var(--muted); font-size: 13px; }
.directory-rail span { grid-column: 2; grid-row: 1 / span 2; color: var(--accent); }

.directory-heading {
    display: flex;
    align-items: end;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 9px 24px;
    margin-bottom: 19px;
}
.directory-heading h2 { font-size: clamp(29px, 4vw, 49px); font-weight: 640; letter-spacing: -.045em; }
.directory-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 0 24px;
    padding: 5px 0;
    border-block: 1px solid var(--line);
}
.directory-tabs a {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    min-height: 43px;
    color: var(--accent);
    font-size: 14px;
    font-weight: 650;
}
.directory-tabs a:hover { text-decoration: underline; text-underline-offset: 4px; }
.directory-group { margin-top: clamp(27px, 3.6vw, 50px); }
.directory-group h2:not(.sr-only) {
    margin-bottom: 17px;
    padding-bottom: 13px;
    border-bottom: 1px solid var(--line);
    font-size: clamp(26px, 3.2vw, 43px);
    font-weight: 640;
}
.directory-group .project-grid { gap: clamp(17px, 2.4vw, 29px); }
.directory-next {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 15px 25px;
    margin-top: clamp(34px, 5vw, 65px);
    padding: clamp(17px, 3vw, 37px);
    border: 1px solid var(--line);
    border-radius: 8px;
    background: #e8eef7;
}
.directory-next h2 { font-size: clamp(24px, 2.9vw, 36px); }

.systems-index .catalog-group {
    display: grid;
    grid-template-columns: minmax(140px, .75fr) minmax(0, 2.25fr);
    align-items: start;
    gap: 13px clamp(17px, 3.5vw, 47px);
    margin-top: 23px;
    padding-top: 24px;
    border-top: 1px solid var(--line);
}
.systems-index .catalog-group h2 { font-size: clamp(20px, 2.3vw, 30px); }
.systems-index .catalog-grid { grid-template-columns: repeat(auto-fit, minmax(min(100%, 240px), 1fr)); margin: 0; }
.systems-index .catalog-item strong { font-size: clamp(17px, 1.8vw, 21px); }
.systems-index .catalog-item-description { line-height: 1.5; }

.site-intro-text-only { grid-template-columns: 1fr; }
.demo-modes {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--soft);
}
.demo-modes > div { padding: clamp(15px, 2.1vw, 26px); }
.demo-modes > div + div { border-left: 1px solid var(--line); }
.demo-modes h3 { font-size: clamp(17px, 1.9vw, 22px); letter-spacing: -.025em; }
.demo-modes p { margin-top: 4px; color: var(--muted); font-size: 14px; }
.demo-directory .directory-tabs { margin-top: 22px; }
.demo-directory .directory-group { margin-top: 26px; }
.demo-mode { display: inline-block; margin-top: 10px; color: var(--accent); font-size: 13px; font-weight: 640; }

@media (max-width: 710px) {
    .systems-index .catalog-group { grid-template-columns: 1fr; }
}
@media (max-width: 575px) {
    .directory-rail, .demo-modes { grid-template-columns: 1fr; }
    .directory-rail a + a, .demo-modes > div + div { border-left: 0; border-top: 1px solid var(--line); }
    .directory-tabs { gap: 0 15px; }
}