:root {
  --white: #ffffff;
  --soft-white: rgba(255, 255, 255, .78);
  --dim-white: rgba(255, 255, 255, .56);
  --black: #000000;
}

* { box-sizing: border-box; }
html, body { width: 100%; min-height: 100%; }
body {
  margin: 0;
  overflow: hidden;
  background: #050302;
  color: var(--white);
  font-family: Inter, "Microsoft YaHei", "PingFang SC", "Segoe UI", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  text-rendering: geometricPrecision;
}
a { color: inherit; text-decoration: none; }
button { font: inherit; }

.landing {
  position: relative;
  width: 100vw;
  height: 100vh;
  min-height: 720px;
  overflow: hidden;
  isolation: isolate;
}

.video-stage,
.video-stage video,
.top-shadow,
.bottom-shadow,
.side-shadow {
  position: absolute;
  inset: 0;
}
.video-stage { z-index: -3; background: #070302; }
.video-stage video {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(1.08) contrast(1.04) brightness(.98);
  transform: scale(1.012);
  transition: opacity .32s ease, filter .32s ease;
}
.video-stage video.is-changing { opacity: .38; filter: blur(8px) saturate(1.12); }
.top-shadow {
  z-index: 1;
  background: linear-gradient(180deg, rgba(0,0,0,.72) 0%, rgba(0,0,0,.32) 11%, rgba(0,0,0,0) 34%);
}
.bottom-shadow {
  z-index: 1;
  background: linear-gradient(0deg, rgba(0,0,0,.58) 0%, rgba(0,0,0,.16) 18%, rgba(0,0,0,0) 45%);
}
.side-shadow {
  z-index: 1;
  background: linear-gradient(90deg, rgba(0,0,0,.34), transparent 18%, transparent 80%, rgba(0,0,0,.30));
}

.transparent-header {
  position: fixed;
  z-index: 20;
  top: 0;
  left: 0;
  right: 0;
  height: 82px;
  padding: 0 28px;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 34px;
  background: transparent;
}
.landing-brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-width: 118px;
  font-size: 23px;
  line-height: 1;
  font-weight: 900;
  letter-spacing: -.04em;
  text-shadow: 0 3px 16px rgba(0,0,0,.42);
}
.brand-symbol {
  width: 36px;
  height: 27px;
  display: inline-flex;
  color: #fff;
}
.brand-symbol svg { width: 100%; height: 100%; filter: drop-shadow(0 4px 16px rgba(0,0,0,.35)); }
.landing-nav {
  display: flex;
  align-items: center;
  gap: clamp(26px, 3.2vw, 58px);
  margin-left: 12px;
}
.landing-nav a {
  color: rgba(255,255,255,.64);
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -.01em;
  text-shadow: 0 2px 12px rgba(0,0,0,.45);
  transition: color .18s ease, transform .18s ease;
}
.landing-nav a:hover { color: #fff; transform: translateY(-1px); }
.landing-actions {
  display: inline-flex;
  align-items: center;
  justify-content: flex-end;
  gap: 24px;
  white-space: nowrap;
}
.plain-action {
  border: 0;
  padding: 0;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: rgba(255,255,255,.92);
  background: transparent;
  cursor: pointer;
  font-weight: 800;
  font-size: 16px;
  text-shadow: 0 2px 12px rgba(0,0,0,.42);
}
.icon-globe {
  width: 18px;
  height: 18px;
  border: 2px solid rgba(255,255,255,.9);
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 0;
}
.chevron { transform: translateY(-1px); color: rgba(255,255,255,.68); }
.trial-button {
  min-width: 122px;
  height: 44px;
  padding: 0 28px;
  border-radius: 999px;
  border: 1px solid rgba(255,255,255,.34);
  background: rgba(0,0,0,.52);
  color: #fff;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 900;
  font-size: 17px;
  box-shadow: inset 0 1px 0 rgba(255,255,255,.12), 0 10px 28px rgba(0,0,0,.24);
  transition: transform .18s ease, background .18s ease, border-color .18s ease;
}
.trial-button:hover { transform: translateY(-1px); background: #000; border-color: rgba(255,255,255,.54); }

.hero-copy {
  position: absolute;
  z-index: 10;
  left: 50%;
  bottom: 15.6vh;
  transform: translateX(-50%);
  width: min(1000px, calc(100% - 42px));
  display: flex;
  flex-direction: column;
  align-items: center;
  pointer-events: none;
}
.hero-copy h1 {
  margin: 0 0 46px;
  white-space: nowrap;
  text-align: center;
  color: #fff;
  font-size: clamp(36px, 3.6vw, 64px);
  line-height: 1;
  letter-spacing: -.045em;
  font-weight: 900;
  text-shadow: 0 4px 18px rgba(0,0,0,.32);
}
.hero-copy h1 span { margin-left: .26em; }
.prompt-launcher {
  pointer-events: auto;
  width: min(860px, 74vw);
  height: 64px;
  padding: 7px 8px 7px 22px;
  display: grid;
  grid-template-columns: 34px 1px 1fr 142px;
  align-items: center;
  gap: 18px;
  border-radius: 999px;
  border: 1px solid rgba(255,255,255,.28);
  background: rgba(255,255,255,.30);
  box-shadow: inset 0 1px 0 rgba(255,255,255,.32), 0 18px 70px rgba(0,0,0,.24);
  backdrop-filter: blur(18px) saturate(1.2);
}
.prompt-avatar {
  width: 34px;
  height: 34px;
  padding: 0;
  overflow: hidden;
  border: 0;
  border-radius: 9px;
  background: #111;
  cursor: pointer;
}
.prompt-avatar img { width: 100%; height: 100%; object-fit: cover; display: block; }
.divider {
  width: 1px;
  height: 22px;
  background: rgba(255,255,255,.72);
}
.prompt-launcher p {
  margin: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  color: rgba(255,255,255,.92);
  font-size: 16px;
  font-weight: 600;
  text-shadow: 0 2px 10px rgba(0,0,0,.30);
}
.create-button {
  height: 50px;
  border-radius: 999px;
  background: #000;
  color: #fff;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  font-weight: 900;
  box-shadow: 0 14px 34px rgba(0,0,0,.22), inset 0 1px 0 rgba(255,255,255,.08);
  transition: transform .18s ease, background .18s ease;
}
.create-button:hover { transform: translateY(-1px); background: #070707; }

.video-switcher {
  position: fixed;
  z-index: 12;
  right: 26px;
  top: 50%;
  transform: translateY(-50%);
  display: flex;
  flex-direction: column;
  gap: 13px;
}
.video-dot {
  width: 34px;
  height: 34px;
  padding: 0;
  border: 1px solid rgba(255,255,255,.18);
  border-radius: 9px;
  overflow: hidden;
  background: rgba(0,0,0,.24);
  opacity: .64;
  cursor: pointer;
  transition: width .22s ease, height .22s ease, opacity .22s ease, border-radius .22s ease, border-color .22s ease, transform .22s ease;
}
.video-dot img { width: 100%; height: 100%; object-fit: cover; display: block; }
.video-dot:hover { opacity: .9; transform: translateX(-2px); }
.video-dot.active {
  width: 47px;
  height: 47px;
  opacity: 1;
  border-radius: 12px;
  border-color: rgba(255,255,255,.72);
  box-shadow: 0 12px 32px rgba(0,0,0,.34), 0 0 0 2px rgba(255,255,255,.18);
}
.scroll-hint {
  display: none;
  position: fixed;
  left: 50%;
  bottom: 24px;
  transform: translateX(-50%);
  z-index: 10;
  color: rgba(255,255,255,.46);
  font-size: 12px;
  letter-spacing: .22em;
  opacity: .55;
}

@media (max-width: 1180px) {
  .transparent-header { gap: 20px; padding: 0 22px; }
  .landing-nav { gap: 20px; }
  .landing-nav a { font-size: 15px; }
  .landing-actions { gap: 14px; }
  .plain-action.download { display: none; }
}
@media (max-width: 860px) {
  body { overflow: hidden; }
  .landing { min-height: 620px; }
  .transparent-header { height: 70px; display: flex; justify-content: space-between; }
  .landing-nav { display: none; }
  .plain-action { display: none; }
  .trial-button { height: 40px; min-width: 104px; padding: 0 18px; font-size: 15px; }
  .hero-copy { bottom: 13vh; }
  .hero-copy h1 {
    margin-bottom: 30px;
    white-space: normal;
    font-size: clamp(34px, 9vw, 56px);
  }
  .hero-copy h1 span { display: block; margin-left: 0; margin-top: 10px; }
  .prompt-launcher {
    width: min(94vw, 620px);
    height: auto;
    grid-template-columns: 32px 1px 1fr;
    grid-template-rows: 48px 48px;
    gap: 8px 13px;
    border-radius: 28px;
    padding: 10px;
  }
  .prompt-launcher p { font-size: 14px; }
  .create-button { grid-column: 1 / -1; height: 46px; }
  .video-switcher { right: 14px; gap: 9px; }
  .video-dot { width: 26px; height: 26px; border-radius: 7px; }
  .video-dot.active { width: 34px; height: 34px; border-radius: 9px; }
}