:root {
    /* These interface values mirror caveviewer.gui.tk_theme.DARK_THEME.
       The --cyan aliases preserve the semantic accent used by page CSS. */
    --bg: #0a0a0d;
    --bg-soft: #12121a;
    --panel: #12121a;
    --panel-2: #1c1c24;
    --text: #cccdd6;
    --title: #f2d98c;
    --muted: #9a9aa6;
    --line: #30303a;
    --line-strong: #5c5c6e;
    --focus: #5d6f8a;
    --accent: #e5a11f;
    --accent-hover: #f0b13a;
    --accent-border: #9c6f18;
    --accent-text: #1a1408;
    --accent-rgb: 229, 161, 31;
    --accent-hover-rgb: 240, 177, 58;
    --cyan: var(--accent);
    --cyan-2: var(--accent-hover);
    --cyan-dim: var(--accent-border);
    --max: 1480px;
    --header-h: 72px;
    --display: "Segoe UI", Inter, Helvetica, Arial, sans-serif;
    --body: Inter, "Segoe UI", Helvetica, Arial, sans-serif;
    --display-weight: 400;
    --display-accent-weight: 520;
    --hero-title-size: clamp(46px, 6vw, 96px);
    --hero-lead-size: clamp(16px, 1.2vw, 18px);
    --hero-title-line-height: .93;
    --hero-title-letter-spacing: -.055em;
    --site-endcap-h: 40px;
    /* Visible labels and metadata use this floor; decorative symbols and
       visually hidden form controls do not carry essential information. */
    --small-text-min: 12px;
}

* {
    box-sizing: border-box;
}

html {
    overflow-y: auto;
    background: var(--bg);
    scroll-behavior: smooth;
}

body {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    min-height: 100svh;
    margin: 0;
    overflow-x: hidden;
    color: var(--text);
    background: var(--bg);
    font-family: var(--body);
    -webkit-font-smoothing: antialiased;
}

body > main {
    flex: 1 0 auto;
}

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

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

button,
input,
textarea,
select {
    font: inherit;
}

button {
    -webkit-appearance: none;
    appearance: none;
}

.shell {
    width: min(calc(100% - 64px), var(--max));
    margin-inline: auto;
}

.sr-only {
    position: absolute !important;
    width: 1px !important;
    height: 1px !important;
    padding: 0 !important;
    margin: -1px !important;
    overflow: hidden !important;
    clip: rect(0, 0, 0, 0) !important;
    white-space: nowrap !important;
    border: 0 !important;
}

/* Shared button treatment used by the Contact form. */
.button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 54px;
    gap: 22px;
    padding: 0 25px;
    border: 1px solid transparent;
    font-size: 13px;
    font-weight: 700;
    letter-spacing: .015em;
    line-height: 1.15;
    text-align: center;
    transition: transform .2s ease, background .2s ease, border-color .2s ease,
        color .2s ease;
}

.button:hover {
    transform: translateY(-2px);
}

.button--primary {
    border-color: var(--accent-border);
    background: var(--accent);
    color: var(--accent-text);
    box-shadow: 0 10px 32px rgba(var(--accent-rgb), .16);
}

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

/* Reveal is opt-in: app.js adds reveal-enhanced only after initialization. */
html.reveal-enhanced [data-reveal] {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity .75s cubic-bezier(.2, .8, .2, 1),
        transform .75s cubic-bezier(.2, .8, .2, 1);
}

/* Keep the first above-the-fold content anchored to the shared page inset. */
html.reveal-enhanced .advantages-page .feature-section:first-child[data-reveal],
html.reveal-enhanced .features-page .feature-section:first-child[data-reveal],
html.reveal-enhanced .media-page .feature-section:first-child[data-reveal],
html.reveal-enhanced .about-team-grid > [data-reveal]:first-child,
html.reveal-enhanced .sponsors-page__grid > [data-reveal]:first-child,
html.reveal-enhanced .contact-page__layout > [data-reveal]:first-child {
    transform: none;
}

html.reveal-enhanced [data-reveal].is-visible {
    opacity: 1;
    transform: none;
}

/* Shared header --------------------------------------------------------- */
.site-header {
    position: fixed;
    inset: 0 0 auto;
    z-index: 100;
    height: var(--header-h);
    border-bottom: 1px solid rgba(242, 217, 140, .12);
    background: rgba(10, 10, 13, .84);
    box-shadow: 0 8px 22px rgba(0, 0, 0, .22);
    backdrop-filter: blur(14px) saturate(.78);
    -webkit-backdrop-filter: blur(14px) saturate(.78);
}

.site-header__inner {
    display: flex;
    align-items: center;
    justify-content: flex-start;
    width: min(calc(100% - 64px), var(--max));
    height: 100%;
    gap: 24px;
    margin: auto;
}

.site-home {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    flex: 0 0 64px;
    width: 64px;
    height: 36px;
    color: var(--text);
    font-family: var(--display);
    font-size: 16px;
    font-weight: 520;
    letter-spacing: .02em;
    white-space: nowrap;
    transition: color .2s ease;
}

.site-home__mark {
    width: 100%;
    height: 100%;
    object-fit: contain;
    transition: filter .18s ease, transform .18s ease;
}

.site-home:hover,
.site-home:focus-visible {
    color: var(--accent);
}

.site-home:hover .site-home__mark,
.site-home:focus-visible .site-home__mark {
    filter: brightness(1.14);
    transform: translateY(-1px);
}

.site-home:focus-visible {
    outline: 1px solid rgba(var(--accent-rgb), .72);
    outline-offset: 4px;
}

.primary-nav {
    display: flex;
    align-items: center;
    gap: clamp(22px, 2.4vw, 34px);
    margin-left: auto;
}

.primary-nav > a {
    position: relative;
    display: block;
    padding: 24px 0 22px;
    color: var(--text);
    font-family: var(--display);
    font-size: 16px;
    font-weight: 520;
    letter-spacing: .02em;
    line-height: normal;
    white-space: nowrap;
    transition: color .2s ease;
}

.primary-nav > a:hover,
.primary-nav > a:focus-visible,
.primary-nav > a[aria-current="page"] {
    color: var(--accent);
}

.primary-nav > a:focus-visible,
.primary-nav > a[aria-current="page"] {
    text-decoration: underline;
    text-decoration-thickness: 2px;
    text-underline-offset: 5px;
}

.primary-nav > a:focus-visible {
    outline: 2px solid rgba(242, 217, 140, .82);
    outline-offset: 4px;
}

.header-download {
    display: inline-flex;
    align-self: center;
    align-items: center;
    justify-content: center;
    gap: 8px;
    flex: 0 0 auto;
    min-width: 124px;
    min-height: 38px;
    padding: 0 13px;
    border: 1px solid rgba(242, 217, 140, .34);
    background: transparent;
    color: var(--title);
    font-family: var(--display);
    font-size: 13px;
    font-weight: 700;
    letter-spacing: .015em;
    line-height: normal;
    white-space: nowrap;
    transition: border-color .18s ease, color .18s ease;
}

.header-download svg {
    width: 17px;
    height: 17px;
    flex: 0 0 auto;
}

.header-download:hover,
.header-download:focus-visible {
    border-color: var(--accent);
    background: transparent;
    color: var(--accent);
}

.header-download:focus-visible {
    outline: 1px solid rgba(242, 217, 140, .82);
    outline-offset: 3px;
}

.menu-toggle {
    display: none;
}

main [id] {
    scroll-margin-top: calc(var(--header-h) + 18px);
}

#main-content {
    scroll-margin-top: calc(var(--header-h) + 18px);
}

/* Keyboard users can bypass repeated navigation and land below the header. */
.skip-link {
    position: fixed;
    top: 10px;
    left: 10px;
    z-index: 200;
    padding: 10px 14px;
    border: 1px solid var(--accent-border);
    background: var(--accent);
    color: var(--accent-text);
    font-size: 14px;
    font-weight: 700;
    transform: translateY(-160%);
}

.skip-link:focus-visible {
    transform: translateY(0);
    outline: 2px solid var(--title);
    outline-offset: 3px;
}

/* The canonical pages use this compact endcap, not the retired full footer. */
.site-endcap {
    flex: 0 0 auto;
    min-height: var(--site-endcap-h);
    overflow: visible;
    border: 0;
    background: transparent;
}

.site-endcap__inner {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr);
    align-items: center;
    width: min(calc(100% - 32px), var(--max));
    min-height: var(--site-endcap-h);
    column-gap: 6px;
    padding-block: 6px;
    margin-inline: auto;
    color: var(--muted);
    line-height: 1.2;
}

.site-endcap__copyright,
.site-endcap__partner {
    font-size: calc(var(--small-text-min) + 1px);
}

.site-endcap__partner {
    min-width: 0;
    margin-left: auto;
    text-align: right;
}

/* Intermediate desktop keeps the primary navigation inline. */
@media (max-width: 1040px) {
    .site-header__inner {
        width: min(calc(100% - 40px), var(--max));
        gap: 18px;
    }

    .primary-nav {
        gap: clamp(14px, 2.2vw, 22px);
    }

    .site-home,
    .primary-nav > a {
        font-size: 15px;
        letter-spacing: .015em;
    }
}

/* Small screens replace the inline destinations with a focused menu. */
@media (max-width: 960px) {
    :root {
        --header-h: 64px;
    }

    .site-header__inner {
        width: min(calc(100% - 32px), var(--max));
        gap: 12px;
    }

    .site-home {
        flex-basis: 52px;
        width: 52px;
        height: 30px;
    }

    .header-download {
        display: none;
    }

    .menu-toggle {
        position: relative;
        z-index: 105;
        display: grid;
        width: 44px;
        height: 44px;
        margin-left: auto;
        padding: 0;
        place-items: center;
        border: 1px solid rgba(242, 217, 140, .28);
        border-radius: 0;
        background: rgba(18, 18, 26, .76);
        color: var(--text);
        cursor: pointer;
        transition: border-color .18s ease, background .18s ease, color .18s ease;
    }

    .menu-toggle:hover,
    .menu-toggle:focus-visible,
    .menu-toggle[aria-expanded="true"] {
        border-color: rgba(var(--accent-rgb), .68);
        background: rgba(var(--accent-rgb), .12);
        color: var(--title);
    }

    .menu-toggle > span:not(.sr-only) {
        position: absolute;
        right: 12px;
        left: 12px;
        height: 1px;
        background: currentColor;
        transition: transform .2s ease, top .2s ease;
    }

    .menu-toggle > span:first-child {
        top: 17px;
    }

    .menu-toggle > span:nth-child(2) {
        top: 25px;
    }

    .menu-toggle[aria-expanded="true"] > span:first-child {
        top: 21px;
        transform: rotate(45deg);
    }

    .menu-toggle[aria-expanded="true"] > span:nth-child(2) {
        top: 21px;
        transform: rotate(-45deg);
    }

    .primary-nav {
        position: fixed;
        z-index: 104;
        top: calc(var(--header-h) - 4px);
        right: 12px;
        display: grid;
        width: min(282px, calc(100vw - 24px));
        min-height: 0;
        gap: 0;
        padding: 6px;
        max-height: calc(100dvh - var(--header-h) - 8px);
        overflow-x: hidden;
        overflow-y: auto;
        overscroll-behavior: contain;
        border: 1px solid rgba(242, 217, 140, .20);
        border-radius: 0;
        background: linear-gradient(145deg, rgba(29, 29, 38, .99), rgba(14, 14, 19, .99));
        box-shadow: 0 22px 48px rgba(0, 0, 0, .46);
        opacity: 0;
        visibility: hidden;
        pointer-events: none;
        transform: translateY(-7px);
        transition: opacity .18s ease, visibility .18s ease, transform .18s ease;
    }

    .primary-nav.is-open {
        opacity: 1;
        visibility: visible;
        pointer-events: auto;
        transform: none;
    }

    .primary-nav > a {
        display: flex;
        align-items: center;
        width: 100%;
        min-height: 43px;
        margin: 0;
        padding: 10px;
        border: 0;
        border-radius: 0;
        background: none;
        color: var(--text);
        font-size: 15px;
        font-weight: 520;
        letter-spacing: .015em;
        line-height: normal;
        white-space: normal;
    }

    .primary-nav > a:hover,
    .primary-nav > a:focus-visible {
        background: rgba(var(--accent-rgb), .10);
        color: var(--title);
    }
}

@media (max-width: 760px) {
    :root {
        --hero-title-size: clamp(36px, 11.5vw, 52px);
        --hero-lead-size: 16px;
    }
}

/* Motion is an enhancement, not a requirement. */
@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

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

    html.reveal-enhanced [data-reveal] {
        opacity: 1 !important;
        transform: none !important;
    }
}