/* ============================================================================
 * ZIVOX — AI Innovation Challenge 2027
 *
 * Loaded ONLY by the pages that use it (/ and /challenge/) so the rest of the
 * site pays nothing for it. Everything here builds on the existing tokens in
 * base.css; no new colours, fonts or dependencies are introduced.
 *
 * Contents
 *   1. Announcement popup
 *   2. Homepage banner carousel
 *   3. Challenge page blocks (hero stats, schedule, prizes, benefits, FAQ)
 * ==========================================================================*/

/* --------------------------------------------------------------------------
 * 1. Announcement popup
 *
 * A native <dialog> would need a polyfill on older iOS Safari; this is a plain
 * fixed-position overlay so it works everywhere with no dependency. It is
 * opt-in via .is-open, so the page renders identically if the script never
 * runs — no flash of an empty box.
 * ------------------------------------------------------------------------*/

.zx-promo {
  position: fixed;
  inset: 0;
  z-index: 240;
  display: none;
  padding: 18px;
  overflow-y: auto;
  overscroll-behavior: contain;
}
.zx-promo.is-open { display: flex; align-items: center; justify-content: center; }

.zx-promo-scrim {
  position: fixed;
  inset: 0;
  background: rgba(8, 16, 38, .58);
  -webkit-backdrop-filter: blur(4px);
  backdrop-filter: blur(4px);
}

.zx-promo-card {
  position: relative;
  width: 100%;
  max-width: 880px;
  margin: auto;
  background: #fff;
  border-radius: var(--r-lg);
  box-shadow: var(--sh-4);
  overflow: hidden;
  display: grid;
  grid-template-columns: 1fr;
}

@media (min-width: 720px) {
  .zx-promo-card { grid-template-columns: 300px 1fr; }
}

/* Art panel: the poster is decorative here; the readable copy lives alongside
   it as real text so screen readers and search engines never depend on it. */
.zx-promo-art {
  position: relative;
  background: #071022;
  min-height: 180px;
}
.zx-promo-art img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 22%;
}
@media (min-width: 720px) {
  .zx-promo-art { min-height: 100%; }
  .zx-promo-art img { position: absolute; inset: 0; }
}

.zx-promo-body {
  padding: 24px 24px 22px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
@media (max-width: 719px) {
  .zx-promo-body { padding: 20px 18px 18px; }
}

.zx-promo-kicker {
  margin: 0;
  font-size: 11px;
  font-weight: 800;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--vio);
}

.zx-promo-title {
  margin: 0;
  font-family: Sora, var(--font-head, sans-serif);
  font-size: clamp(20px, 3.4vw, 27px);
  line-height: 1.2;
  font-weight: 700;
  color: var(--ink);
}

.zx-promo-sub {
  margin: 0;
  font-size: 14px;
  line-height: 1.6;
  color: var(--muted);
}

.zx-promo-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 2px 0 0;
  padding: 0;
  list-style: none;
}
.zx-promo-meta li {
  font-size: 12px;
  font-weight: 600;
  color: var(--ink-2);
  background: var(--bg-2);
  border: 1px solid var(--line);
  border-radius: var(--pill);
  padding: 5px 11px;
}

.zx-promo-cta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin-top: 6px;
}

/* The "registration opens" note is deliberately NOT a link: there is nothing
   to link to yet, and a dead button would be worse than none. */
.zx-promo-soon {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--warn);
  background: var(--warn-bg);
  border-radius: var(--pill);
  padding: 7px 13px;
}
.zx-promo-soon svg { width: 14px; height: 14px; flex: none; }

.zx-promo-x {
  position: absolute;
  top: 10px;
  right: 10px;
  z-index: 2;
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border: 0;
  border-radius: 50%;
  cursor: pointer;
  color: #fff;
  background: rgba(6, 12, 28, .55);
  -webkit-backdrop-filter: blur(6px);
  backdrop-filter: blur(6px);
}
.zx-promo-x svg { width: 17px; height: 17px; }
.zx-promo-x:hover { background: rgba(6, 12, 28, .78); }
.zx-promo-x:focus-visible { outline: 3px solid #fff; outline-offset: 2px; }

/* Lock the page behind the overlay without losing scroll position. */
body.zx-promo-open { overflow: hidden; }

@media (prefers-reduced-motion: no-preference) {
  .zx-promo.is-open .zx-promo-card {
    animation: zxPromoIn .32s cubic-bezier(.22, .8, .28, 1) both;
  }
  @keyframes zxPromoIn {
    from { opacity: 0; transform: translateY(14px) scale(.985); }
    to   { opacity: 1; transform: none; }
  }
}

/* --------------------------------------------------------------------------
 * 2. Homepage banner carousel
 * ------------------------------------------------------------------------*/

.zx-carousel {
  position: relative;
  border-radius: var(--r-lg);
  overflow: hidden;
  background: #071022;
  box-shadow: var(--sh-3);
  isolation: isolate;
}

.zx-carousel-track {
  display: flex;
  transition: transform .5s cubic-bezier(.22, .8, .28, 1);
  will-change: transform;
}
@media (prefers-reduced-motion: reduce) {
  .zx-carousel-track { transition: none; }
}

.zx-slide {
  flex: 0 0 100%;
  position: relative;
  display: grid;
  min-height: 300px;
}
@media (min-width: 760px) {
  .zx-slide {
    grid-template-columns: 1fr 260px;
    align-items: center;
    min-height: 260px;
  }
}

.zx-slide-art { position: absolute; inset: 0; z-index: 0; }
.zx-slide-art img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 20%;
}
@media (min-width: 760px) {
  .zx-slide-art { left: auto; width: 300px; }
}

/* Readable scrim behind the copy so the poster's own text never fights ours. */
.zx-slide-art::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(6, 12, 28, .60) 0%, rgba(6, 12, 28, .88) 62%, rgba(6, 12, 28, .95) 100%);
}
@media (min-width: 760px) {
  .zx-slide-art::after {
    background: linear-gradient(90deg, rgba(6, 12, 28, .97) 0%, rgba(6, 12, 28, .92) 45%, rgba(6, 12, 28, .35) 100%);
  }
}

.zx-slide-body {
  position: relative;
  z-index: 1;
  padding: 26px 22px 24px;
  display: flex;
  flex-direction: column;
  gap: 11px;
  color: #fff;
}
@media (min-width: 760px) {
  .zx-slide-body { padding: 30px 28px; grid-column: 1; max-width: 560px; }
}

.zx-slide-kicker {
  margin: 0;
  font-size: 10.5px;
  font-weight: 800;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: #a9b8ff;
}

.zx-slide-title {
  margin: 0;
  font-family: Sora, var(--font-head, sans-serif);
  font-size: clamp(21px, 3.6vw, 32px);
  line-height: 1.18;
  font-weight: 700;
  color: #fff;
}

.zx-slide-text {
  margin: 0;
  font-size: 14px;
  line-height: 1.62;
  color: rgba(233, 239, 255, .86);
  max-width: 46ch;
}

.zx-slide-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.zx-slide-tags li {
  font-size: 11.5px;
  font-weight: 600;
  color: #dbe4ff;
  border: 1px solid rgba(190, 205, 255, .30);
  border-radius: var(--pill);
  padding: 4px 10px;
}

.zx-slide-cta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 9px;
  margin-top: 4px;
}

/* Association lockup: "In Association With" + the InternzValley mark. The logo
   is a transparent PNG/WebP, so it sits on the dark slide without a plate. */
.zx-assoc {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-size: 10.5px;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: rgba(226, 235, 255, .72);
}
.zx-assoc img {
  display: block;
  width: 104px;
  height: auto;
  filter: brightness(1.18) saturate(1.05);
}

.zx-carousel-nav {
  position: absolute;
  z-index: 3;
  bottom: 14px;
  display: flex;
  align-items: center;
  gap: 7px;
}
.zx-carousel-nav.end { right: 14px; }
.zx-carousel-nav.start { left: 14px; }

.zx-cbtn {
  width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  border: 1px solid rgba(255, 255, 255, .28);
  border-radius: 50%;
  background: rgba(8, 16, 38, .48);
  color: #fff;
  cursor: pointer;
  -webkit-backdrop-filter: blur(6px);
  backdrop-filter: blur(6px);
}
.zx-cbtn:hover { background: rgba(8, 16, 38, .74); }
.zx-cbtn:focus-visible { outline: 2px solid #fff; outline-offset: 2px; }
.zx-cbtn svg { width: 15px; height: 15px; }

.zx-dots {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-left: 4px;
  padding: 0;
  list-style: none;
}
.zx-dots button {
  width: 7px;
  height: 7px;
  padding: 0;
  border: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, .38);
  cursor: pointer;
}
.zx-dots button[aria-current="true"] {
  width: 20px;
  border-radius: var(--pill);
  background: #fff;
}

/* --------------------------------------------------------------------------
 * 3. Challenge page blocks
 * ------------------------------------------------------------------------*/

.zx-stat-row {
  display: grid;
  gap: 12px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}
@media (min-width: 720px) { .zx-stat-row { grid-template-columns: repeat(4, minmax(0, 1fr)); } }

.zx-stat {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--r);
  padding: 14px 15px;
  min-width: 0;
}
.zx-stat b {
  display: block;
  font-family: Sora, var(--font-head, sans-serif);
  font-size: 20px;
  line-height: 1.2;
  color: var(--ink);
  overflow-wrap: anywhere;
}
.zx-stat span {
  display: block;
  margin-top: 3px;
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: .05em;
  text-transform: uppercase;
  color: var(--faint);
}

/* Prizes */
.zx-prizes {
  display: grid;
  gap: 12px;
  grid-template-columns: 1fr;
  margin: 0;
  padding: 0;
  list-style: none;
}
@media (min-width: 640px) { .zx-prizes { grid-template-columns: repeat(3, minmax(0, 1fr)); } }

.zx-prize {
  position: relative;
  padding: 18px 16px;
  border-radius: var(--r);
  border: 1px solid var(--line);
  background: #fff;
  text-align: center;
  min-width: 0;
}
.zx-prize.first {
  border-color: rgba(180, 130, 20, .38);
  background: linear-gradient(180deg, #fffdf4, #fff);
  box-shadow: var(--sh-2);
}
.zx-prize-rank {
  font-size: 11px;
  font-weight: 800;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--faint);
}
.zx-prize-amt {
  display: block;
  margin: 6px 0 2px;
  font-family: Sora, var(--font-head, sans-serif);
  font-size: clamp(22px, 4vw, 28px);
  font-weight: 700;
  color: var(--ink);
}
.zx-prize.first .zx-prize-amt { color: #8a6400; }

/* Schedule table: becomes stacked cards below 760px, matching .tbl.resp. */
.zx-sched { margin: 0; padding: 0; list-style: none; display: grid; gap: 9px; }
.zx-sched li {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 4px 14px;
  align-items: baseline;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  background: #fff;
  min-width: 0;
}
.zx-sched .t { font-size: 13.5px; font-weight: 600; color: var(--ink); }
.zx-sched .d { font-size: 12.5px; font-weight: 700; color: var(--brand-ink); white-space: nowrap; }
.zx-sched .n { grid-column: 1 / -1; font-size: 12px; color: var(--muted); }

@media (max-width: 420px) {
  .zx-sched li { grid-template-columns: 1fr; }
  .zx-sched .d { justify-self: start; white-space: normal; }
  .zx-assoc img { width: 92px; }
}

/* Benefits */
.zx-benefits {
  display: grid;
  gap: 10px;
  grid-template-columns: 1fr;
  margin: 0;
  padding: 0;
  list-style: none;
}
@media (min-width: 640px) { .zx-benefits { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
.zx-benefits li {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  background: #fff;
  font-size: 13.5px;
  line-height: 1.55;
  color: var(--ink-2);
  min-width: 0;
}
.zx-benefits svg { width: 16px; height: 16px; flex: none; margin-top: 2px; color: var(--ok); }

/* Notice strip for anything awaiting a decision */
.zx-note {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  padding: 12px 14px;
  border-radius: var(--r-sm);
  border: 1px solid rgba(168, 90, 6, .22);
  background: var(--warn-bg);
  color: #7a4405;
  font-size: 13px;
  line-height: 1.58;
}
.zx-note svg { width: 16px; height: 16px; flex: none; margin-top: 2px; }
.zx-note strong { color: #653803; }

/* Inline form success/error panel */
.zx-form-msg {
  display: none;
  margin-top: 14px;
  padding: 12px 14px;
  border-radius: var(--r-sm);
  font-size: 13.5px;
  line-height: 1.55;
}
.zx-form-msg.show { display: block; }
.zx-form-msg.ok { background: var(--ok-bg); border: 1px solid rgba(19, 122, 62, .22); color: #0d5730; }
.zx-form-msg.bad { background: var(--bad-bg); border: 1px solid rgba(192, 38, 45, .22); color: #861b20; }

/* Radio pair (Email / WhatsApp) */
.zx-choice {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 4px;
  padding: 0;
  border: 0;
}
.zx-choice legend {
  padding: 0;
  margin-bottom: 7px;
  font-size: 12.5px;
  font-weight: 700;
  color: var(--ink-2);
}
.zx-choice label {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 9px 14px;
  border: 1px solid var(--line);
  border-radius: var(--pill);
  background: #fff;
  font-size: 13px;
  font-weight: 600;
  color: var(--ink-2);
  cursor: pointer;
}
.zx-choice input { margin: 0; }
.zx-choice label:has(input:checked) {
  border-color: var(--brand);
  background: var(--info-bg);
  color: var(--brand-ink);
}