/* ==========================================================================
   Qiskit Fall Fest 2026 — Landing page
   Palette drawn from Qiskit Fall Fest hero illustration:
   dark violet #31135E, violet #8B3FFC / #A56EFF / #BE95FF / #D4BBFF,
   pink #EE5396 / #FF7EB6 / #FFAFD2, blue #0F62FE / #4589FF / #BDCDEF,
   light blue #DAE5FC, near-white cloud #F2F4F8.
   No pure white or pure black anywhere.

   The page uses a single bright hero ("sky") above one solid, very dark
   violet body background (#1A0B3A). Sections are separated with centered
   fading dividers, spacing, and contained design objects (e.g. the CTA
   card) — never by per-section background changes.
   ========================================================================== */

:root {
    --violet-deep: #31135E;
    --violet-deeper: #28105B;
    --violet-night: #1A0B3A;
    --violet-dark: #4A1D8B;
    --violet: #8B3FFC;
    --violet-mid: #A56EFF;
    --violet-light: #BE95FF;
    --violet-pale: #D4BBFF;
    --pink: #EE5396;
    --pink-mid: #FF7EB6;
    --pink-pale: #FFAFD2;
    --blue: #0F62FE;
    --blue-mid: #4589FF;
    --blue-soft: #BDCDEF;
    --cloud: #F2F4F8;

    --grad-pink: linear-gradient(135deg, #EE5396, #FF7EB6);
    --grad-violet: linear-gradient(135deg, #8B3FFC, #A56EFF);
    --grad-blue: linear-gradient(135deg, #0F62FE, #4589FF);
    --grad-hero: linear-gradient(160deg, #28105B 0%, #3C1772 35%, #6929C4 68%, #8B3FFC 100%);

    --font: "Segoe UI", "Helvetica Neue", Arial, system-ui, sans-serif;
}

/* ---------- Base ---------- */
html, body {
    margin: 0;
    padding: 0;
    height: 100%;
    overflow: hidden;
    background: var(--violet-night);
    color: var(--cloud);
    font-family: var(--font);
    -webkit-font-smoothing: antialiased;
    scroll-behavior: smooth;
}

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

img { max-width: 100%; }

::selection {
    background: var(--pink);
    color: var(--violet-deep);
}

/* Hide the scrollbar on the parallax scroller */
.parallax-wrapper { scrollbar-width: none; }
.parallax-wrapper::-webkit-scrollbar { display: none; }

/* ---------- Typography helpers ---------- */
.eyebrow {
    margin: 0 0 0.6rem;
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.22em;
    text-transform: uppercase;
    color: var(--pink-mid);
}
.eyebrow.light { color: var(--violet-mid); }

h2 {
    margin: 0 0 1.25rem;
    font-size: clamp(1.7rem, 3.2vw, 2.5rem);
    line-height: 1.15;
    color: var(--cloud);
}

.lede {
    max-width: 46rem;
    font-size: 1.1rem;
    line-height: 1.7;
    color: var(--blue-soft);
}

.section-sub {
    max-width: 40rem;
    margin: -0.5rem 0 0;
    font-size: 1rem;
    line-height: 1.65;
    color: var(--blue-soft);
}

/* ---------- Navigation ---------- */
/* Backgroundless bar: a whisper scrim keeps it readable over the light
   hero, and a gradient hairline (via ::after) grounds it. */
.site-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding: 0.85rem 2rem;
    background: linear-gradient(180deg, rgba(26, 11, 58, 0.45), rgba(26, 11, 58, 0));
    transform: translateY(-110%);
    opacity: 0;
    pointer-events: none;
    transition: transform 0.35s ease, opacity 0.35s ease;
}
.site-nav.is-visible {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
}
.site-nav::after {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    bottom: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(190, 149, 255, 0.4) 20%, rgba(190, 149, 255, 0.4) 80%, transparent);
}

.brand {
    display: flex;
    align-items: center;
    gap: 0.7rem;
    text-decoration: none;
    color: var(--cloud);
}
.brand-mark {
    width: 2.6rem;
    height: auto;
    display: block;
}
.brand-name {
    font-weight: 600;
    letter-spacing: 0.02em;
}
.brand-name em {
    font-style: normal;
    color: var(--pink-mid);
}
.brand-name strong {
    font-weight: 700;
    color: var(--violet-light);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 1.4rem;
}
.nav-links a {
    position: relative;
    padding-bottom: 0.25rem;
    color: var(--blue-soft);
    text-decoration: none;
    font-size: 0.92rem;
    font-weight: 600;
}
.nav-links a::after {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    bottom: 0;
    height: 2px;
    border-radius: 2px;
    background: var(--grad-pink);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.22s ease;
}
.nav-links a:hover::after,
.nav-links a:focus-visible::after {
    transform: scaleX(1);
}

.nav-links a.nav-cta {
    color: var(--pink-mid);
}

/* ---------- 1. Scroll container + perspective ---------- */
.parallax-wrapper {
    height: 100vh;
    overflow-x: hidden;
    overflow-y: auto;
    perspective: 1px;
    scroll-behavior: smooth;
}

/* ---------- Parallax group ---------- */
/* pointer-events: none so Chromium hit-tests the 3D-transformed layers
   correctly; interactivity is restored on the foreground layer. */
.parallax-group.hero {
    position: relative;
    height: 100vh;
    transform-style: preserve-3d;
    pointer-events: none;
}

.layer {
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    pointer-events: none;
}

/* ---------- 2. Background layer (pushed back, scrolls slower) ---------- */
/* Raw Hero 1 illustration, kept as-is; image covers the layer.
   Spans 100vw (not the scrollbar-narrowed wrapper width) so the hero
   image reaches both screen edges. */
.layer-bg {
    position: absolute;
    top: 0;
    left: 50%;
    width: 100vw;
    height: 100%;
    transform: translateX(-50%) translateZ(-1px) scale(2);
    z-index: -2;
}
.hero-img {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
}

/* ---------- 3. Foreground layer (same depth as the hero background,
   so the hero content scrolls at the same speed and the content below
   scrolls faster and covers it) ---------- */
.layer-fg {
    transform: translateZ(-1px) scale(2);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 5rem 2rem 3.5rem;
    pointer-events: auto;
}

/* Soft light base behind the text for readability */
.hero-content {
    position: relative;
    z-index: 1;
    max-width: 52rem;
    padding: 2.6rem 3rem;
    background: radial-gradient(
        ellipse at center,
        rgba(218, 229, 252, 0.85) 0%,
        rgba(218, 229, 252, 0.5) 45%,
        rgba(218, 229, 252, 0) 70%
    );
}

/* Glowing colour blobs behind the text */
.hero-content::before,
.hero-content::after {
    content: "";
    position: absolute;
    z-index: -1;
    border-radius: 50%;
    pointer-events: none;
}
.hero-content::before {
    width: 26rem;
    height: 26rem;
    top: -8rem;
    left: -6rem;
    background: rgba(238, 83, 150, 0.55);
    filter: blur(64px);
}
.hero-content::after {
    width: 30rem;
    height: 30rem;
    bottom: -10rem;
    right: -7rem;
    background: rgba(139, 63, 252, 0.5);
    filter: blur(72px);
}

.hero .eyebrow { color: var(--pink); }

.hero-title {
    margin: 0 0 1.1rem;
    font-size: clamp(2.6rem, 7vw, 5.5rem);
    line-height: 1.05;
    letter-spacing: -0.01em;
    color: var(--violet-deep);
}
/* .accent-pink {
    background: linear-gradient(135deg, var(--pink), #E13D8A);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}
.accent-violet {
    background: linear-gradient(135deg, var(--violet), var(--pink));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
} */

.hero-sub {
    max-width: 40rem;
    margin: 0 auto 2rem;
    font-size: clamp(1.05rem, 2vw, 1.3rem);
    line-height: 1.6;
    color: var(--violet-deep);
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2rem;
}

.btn {
    display: inline-block;
    padding: 0.85rem 1.8rem;
    border-radius: 999px;
    font-weight: 700;
    font-size: 0.98rem;
    text-decoration: none;
    transition: transform 0.18s ease, box-shadow 0.18s ease;
}
.btn:hover { transform: translateY(-2px); }

.btn-pink {
    background: var(--grad-pink);
    color: var(--violet-deep);
    box-shadow: 0 2px 10px rgba(238, 83, 150, 0.3);
}
.btn-pink:hover { box-shadow: 0 4px 14px rgba(255, 126, 182, 0.4); }

.btn-ghost {
    border: 1.5px solid var(--violet-light);
    color: var(--violet-light);
    background: rgba(139, 63, 252, 0.14);
}
.btn-ghost:hover {
    background: rgba(139, 63, 252, 0.32);
    box-shadow: 0 2px 10px rgba(139, 63, 252, 0.3);
}

/* Dark variant for the light hero */
.hero .btn-ghost {
    border-color: var(--violet-deep);
    color: var(--violet-deep);
    background: rgba(218, 229, 252, 0.4);
}
.hero .btn-ghost:hover {
    background: rgba(218, 229, 252, 0.75);
    box-shadow: 0 2px 10px rgba(74, 29, 139, 0.2);
}

.hero-meta {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    gap: 0.7rem;
    margin: 0;
    font-size: 0.92rem;
    font-weight: 600;
    letter-spacing: 0.04em;
    color: var(--violet-dark);
}
.hero-meta .dot {
    width: 0.35rem;
    height: 0.35rem;
    border-radius: 50%;
    background: var(--violet-mid);
}

/* ---------- 4. Regular content sections ---------- */
/* All sections share the page background; a centered fading divider
   separates them instead of changing the background per section. */
.regular-content {
    position: relative;
    z-index: 1;
    min-height: 100vh;
    padding: 6rem 0;
}
.regular-content:not(:first-of-type)::before {
    content: "";
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: min(56rem, 82%);
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(190, 149, 255, 0.35), transparent);
}

.shell {
    max-width: 68rem;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* About — solid page background so it masks the parallax hero behind it
   and the parallax effect stays visible while scrolling. */
.section.about {
    background: var(--violet-night);
}
.section.about h2 { color: var(--cloud); }
.section.about .lede { color: var(--blue-soft); }

.cloud-deco {
    position: absolute;
    inset: 0;
    overflow: hidden;
    pointer-events: none;
}
.cd {
    position: absolute;
    opacity: 0.32;
}
.cd-1 { width: 16rem; top: 10%; left: -4rem; }
.cd-2 { width: 22rem; bottom: 8%; right: -5rem; }

.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(14rem, 1fr));
    gap: 2.4rem;
    margin-top: 3.5rem;
    padding-top: 2.5rem;
    border-top: 1px solid rgba(190, 149, 255, 0.2);
}
.step-num {
    display: block;
    font-size: 1.9rem;
    font-weight: 800;
    line-height: 1;
    color: var(--violet-light);
    margin-bottom: 0.6rem;
}
.step h3 {
    margin: 0 0 0.4rem;
    font-size: 1.05rem;
    color: var(--cloud);
}
.step p {
    margin: 0;
    font-size: 0.93rem;
    line-height: 1.6;
    color: var(--blue-soft);
}

/* Highlights — cards on the shared background */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr));
    gap: 2.4rem;
    margin-top: 2.5rem;
}
.card {
    padding: 1.5rem 0.5rem 0.5rem;
}
.card-icon {
    display: block;
    width: 5.5rem;
    height: 5.5rem;
    margin-bottom: 1.2rem;
    object-fit: contain;
    object-position: left center;
}
.card h3 {
    margin: 0 0 0.5rem;
    font-size: 1.15rem;
    color: var(--cloud);
}
.card p {
    margin: 0;
    font-size: 0.95rem;
    line-height: 1.6;
    color: var(--blue-soft);
}

/* Schedule — rows aligned to the shell width, description left / date right */
.timeline {
    margin-top: 3rem;
}
.tl-row {
    display: grid;
    grid-template-columns: 8rem 1fr;
    align-items: baseline;
    gap: 1.2rem;
    padding: 1.1rem 1.25rem;
}
.tl-row:nth-child(odd) {
    background: rgba(190, 149, 255, 0.07);
}
.tl-when {
    justify-self: end;
    font-size: 0.85rem;
    font-weight: 700;
    letter-spacing: 0.06em;
    color: var(--pink-mid);
    white-space: nowrap;
}
.tl-what {
    text-align: left;
    font-size: 1.05rem;
    color: var(--cloud);
}

/* Speakers */
.speaker-note { color: var(--blue-soft); }

.speaker-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(12rem, 1fr));
    gap: 2.4rem;
    margin-top: 2.5rem;
}
.speaker {
    padding: 1.5rem 0.5rem;
    text-align: center;
}
.avatar {
    display: block;
    width: 7rem;
    height: 7rem;
    margin: 0 auto 1rem;
    object-fit: contain;
}

.speaker h3 {
    margin: 0 0 0.2rem;
    font-size: 1.05rem;
    color: var(--cloud);
}
.speaker p {
    margin: 0;
    font-size: 0.9rem;
    color: var(--blue-soft);
}

/* Sponsors */
.sponsor-cta {
    margin-top: 2.2rem;
    color: var(--blue-soft);
}
.sponsor-cta a {
    color: var(--pink-mid);
    font-weight: 700;
    text-decoration: none;
    border-bottom: 1px solid rgba(255, 126, 182, 0.5);
}

.logo-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(12rem, 1fr));
    gap: 1.6rem;
    margin-top: 2.5rem;
}
.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 5rem;
    font-weight: 700;
    letter-spacing: 0.04em;
    color: var(--violet-pale);
    opacity: 0.8;
}

/* FAQ — fills the full shell width like the other sections */
.faq-list { width: 100%; }

.faq-item {
    border-bottom: 1px solid rgba(190, 149, 255, 0.2);
}
.faq-item summary {
    cursor: pointer;
    padding: 1.1rem 2rem 1.1rem 0;
    font-weight: 700;
    color: var(--cloud);
    list-style: none;
    position: relative;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
    content: "+";
    position: absolute;
    right: 0.2rem;
    top: 50%;
    transform: translateY(-50%);
    font-size: 1.3rem;
    color: var(--pink-mid);
}
.faq-item[open] summary::after { content: "\2013"; }
.faq-item p {
    margin: 0;
    padding: 0 2rem 1.2rem 0;
    font-size: 0.95rem;
    line-height: 1.6;
    color: var(--blue-soft);
}

/* CTA — contained gradient card on the shared page background */
.cta-box {
    padding: 4rem;
    text-align: center;
    background: var(--grad-hero);
    border: 1px solid rgba(190, 149, 255, 0.25);
    border-radius: 1.75rem;
    box-shadow: 0 1.5rem 4rem rgba(16, 7, 36, 0.45);
}
.cta-box .eyebrow { color: var(--pink-pale); }
.cta-text {
    max-width: 36rem;
    margin: 0 auto 2rem;
    font-size: 1.1rem;
    line-height: 1.7;
    color: var(--blue-soft);
}
.cta-actions {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1rem;
}

/* ---------- Footer ---------- */
/* Shares the page background; only a hairline separates it. */
.site-footer {
    padding: 3.5rem 0;
    text-align: center;
    border-top: 1px solid rgba(190, 149, 255, 0.16);
}
.footer-brand {
    margin: 0 0 0.6rem;
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--cloud);
}
.footer-text {
    max-width: 34rem;
    margin: 0 auto 1.4rem;
    font-size: 0.9rem;
    line-height: 1.6;
    color: var(--violet-light);
}
.footer-links {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1.3rem;
}
.footer-links a {
    color: var(--blue-soft);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 600;
}

/* ---------- Responsive ---------- */
@media (max-width: 720px) {
    /* Top bar keeps just the brand, left-aligned */
    .site-nav {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.4rem;
        padding: 0.9rem 1rem;
    }
    /* transform is disabled on mobile in both states so the fixed-positioned
       bottom bar below resolves against the viewport rather than the
       (transformed) top bar; hiding is done with opacity only */
    .site-nav,
    .site-nav.is-visible { transform: none; }

    /* Nav items move to a bottom bar on mobile */
    .nav-links {
        position: fixed;
        bottom: 0;
        left: 0;
        right: 0;
        z-index: 100;
        flex-wrap: wrap;
        justify-content: center;
        gap: 0.9rem;
        padding: 0.7rem 1rem calc(0.7rem + env(safe-area-inset-bottom, 0px));
        background: linear-gradient(180deg, rgba(26, 11, 58, 0), rgba(26, 11, 58, 0.7));
        border-top: 1px solid rgba(190, 149, 255, 0.2);
    }

    .regular-content { padding: 4rem 0; }
    .cta-box { padding: 2.4rem 1.5rem; border-radius: 1.25rem; }
    .hero-content { padding: 1.8rem 1.4rem; }
}