/* ============================================================
   Meow Meow · Intelligence Designed To Evolve
   Single-viewport, full-bleed video-background landing page
   ============================================================ */
:root {
  --bg: #000000;
  --text: #ffffff;
  --muted: #8e8e8e;
  --nav-text: #2e2e2e;
  --pill-dark: #28282a;
  --sign-in-text: #c8c8c8;
  --nav-shadow: 0 4px 14px rgba(0, 0, 0, 0.16);
  --trust-bg: #28282a;
  --trust-border: rgba(255, 255, 255, 0.4);
  --trust-text: #c4c2c3;
  --font-sans: "Inter", "Segoe UI", system-ui, sans-serif;
  --font-display: "BubbledotICG-FinePos", "Geist Pixel Circle", monospace;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html, body { height: 100%; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  overflow: hidden;
  height: 100vh;
  height: 100dvh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ---------------- Background video ---------------- */
.bg {
  position: absolute;
  inset: 0;
  background: #000;
  overflow: hidden;
  z-index: 0;
}
.bg-video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  pointer-events: none;
  z-index: 0;
}

/* ---------------- Page composition ---------------- */
.page {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  height: 100vh;
  height: 100dvh;
  padding: clamp(16px, 2.4vh, 28px) clamp(14px, 3vw, 32px);
  overflow: hidden;
}

/* ---------------- Header ---------------- */
.header {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: clamp(18px, 2.8vw, 28px);
  width: 100%;
  max-width: 720px;
  z-index: 1;
  animation: slideDown 0.7s cubic-bezier(0.22, 1, 0.36, 1) both;
}
@keyframes slideDown {
  from { opacity: 0; transform: translateY(-18px); }
  to { opacity: 1; transform: translateY(0); }
}

.logo {
  flex-shrink: 0;
  width: clamp(40px, 4.4vw, 46px);
  height: clamp(40px, 4.4vw, 46px);
  border-radius: 50%;
  background: #fff;
  box-shadow: var(--nav-shadow);
  display: grid;
  place-items: center;
  transition: transform 0.3s ease;
}
.logo:hover { transform: scale(1.04); }
.logo img {
  width: 72%;
  height: 72%;
  object-fit: contain;
  display: block;
}

.nav-pill {
  flex: 1;
  max-width: 430px;
  height: clamp(44px, 5.2vw, 48px);
  background: #fff;
  border-radius: 999px;
  box-shadow: var(--nav-shadow);
  display: flex;
  align-items: center;
  padding: 4px 8px;
}
.nav-link {
  flex: 1;
  position: relative;
  text-align: center;
  text-decoration: none;
  font-weight: 500;
  font-size: clamp(13px, 1.4vw, 15px);
  letter-spacing: -0.01em;
  color: var(--nav-text);
  opacity: 0.5;
  transition: opacity 0.25s ease;
  line-height: 1;
}
.nav-link:hover { opacity: 0.75; }
.nav-link.active { opacity: 1; }
.nav-link.active::after {
  content: "";
  position: absolute;
  bottom: 5px;
  left: 50%;
  transform: translateX(-50%);
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: #000;
  box-shadow: -5px 0 0 #000, 5px 0 0 #000;
}

.sign-in {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  height: clamp(44px, 5.2vw, 48px);
  padding: 0 clamp(16px, 2vw, 24px);
  background: var(--pill-dark);
  color: var(--sign-in-text);
  border-radius: 999px;
  box-shadow: var(--nav-shadow);
  text-decoration: none;
  font-weight: 500;
  font-size: clamp(13px, 1.4vw, 15px);
  transition: background 0.25s ease, color 0.25s ease, transform 0.25s ease;
}
.sign-in:hover { background: #323234; color: #fff; transform: translateY(-1px); }

/* ---------------- Burger (mobile) ---------------- */
.burger {
  display: none;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: 0;
  background: var(--pill-dark);
  cursor: pointer;
  position: relative;
  flex-shrink: 0;
}
.burger span {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 18px;
  height: 1.5px;
  background: #fff;
  border-radius: 2px;
  transform: translate(-50%, -50%);
  transition: transform 0.3s ease, background 0.3s ease;
}
.burger span:nth-child(1) { transform: translate(-50%, calc(-50% - 6px)); }
.burger span:nth-child(2) { transform: translate(-50%, -50%); }
.burger span:nth-child(3) { transform: translate(-50%, calc(-50% + 6px)); }
body.menu-open .burger { background: #fff; }
body.menu-open .burger span { background: #000; }
body.menu-open .burger span:nth-child(1) { transform: translate(-50%, -50%) rotate(45deg); }
body.menu-open .burger span:nth-child(2) { opacity: 0; }
body.menu-open .burger span:nth-child(3) { transform: translate(-50%, -50%) rotate(-45deg); }

.overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.62);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  z-index: 5;
  animation: overlayIn 0.28s ease both;
}
@keyframes overlayIn { from { opacity: 0; } to { opacity: 1; } }

.mobile-menu {
  position: fixed;
  top: 84px;
  left: 50%;
  transform: translateX(-50%);
  width: min(320px, calc(100vw - 40px));
  background: #fff;
  border-radius: 28px;
  padding: 22px 18px 20px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.45);
  z-index: 6;
  display: flex;
  flex-direction: column;
  gap: 4px;
  animation: menuIn 0.38s cubic-bezier(0.22, 1, 0.36, 1) both;
}
@keyframes menuIn {
  from { opacity: 0; transform: translateX(-50%) translateY(-12px) scale(0.98); }
  to { opacity: 1; transform: translateX(-50%) translateY(0) scale(1); }
}
.m-link {
  position: relative;
  text-align: center;
  text-decoration: none;
  color: var(--nav-text);
  font-weight: 500;
  font-size: 15px;
  padding: 12px 0;
  opacity: 0.6;
  animation: linkIn 0.4s cubic-bezier(0.22, 1, 0.36, 1) both;
}
.m-link:nth-child(1) { animation-delay: 0.04s; }
.m-link:nth-child(2) { animation-delay: 0.08s; }
.m-link:nth-child(3) { animation-delay: 0.12s; }
.m-link:nth-child(4) { animation-delay: 0.16s; }
@keyframes linkIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}
.m-link:hover { opacity: 0.85; }
.m-link.active { opacity: 1; }
.m-link.active::after {
  content: "";
  position: absolute;
  bottom: 8px;
  left: 50%;
  transform: translateX(-50%);
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: #000;
  box-shadow: -5px 0 0 #000, 5px 0 0 #000;
}
.m-signin {
  margin-top: 10px;
  text-align: center;
  text-decoration: none;
  background: var(--pill-dark);
  color: var(--sign-in-text);
  border-radius: 999px;
  padding: 13px 0;
  font-weight: 500;
  font-size: 15px;
  animation: linkIn 0.4s cubic-bezier(0.22, 1, 0.36, 1) 0.2s both;
}

/* ---------------- Hero ---------------- */
.hero {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  max-width: 900px;
  width: 100%;
  z-index: 1;
  min-height: 0;
}

/* Trust row */
.trust-row {
  display: inline-flex;
  align-items: center;
  margin-bottom: clamp(16px, 2.5vh, 26px);
  --trust-size: clamp(36px, 4.5vw, 42px);
}
.trust-avatar {
  width: var(--trust-size);
  height: var(--trust-size);
  border-radius: 50%;
  background: var(--trust-bg);
  border: 1px solid var(--trust-border);
  padding: 5px;
  position: relative;
  transition: transform 0.35s ease;
}
.trust-avatar.a1 { z-index: 1; }
.trust-avatar.a2 { margin-left: calc(var(--trust-size) * -0.42); z-index: 2; }
.trust-avatar.a3 { margin-left: calc(var(--trust-size) * -0.42); z-index: 4; }
.trust-avatar.a1:hover { transform: translateY(-2px); }
.trust-avatar.a2:hover { transform: translateY(-4px); }
.trust-avatar.a3:hover { transform: translateY(-2px); }
.trust-inner {
  display: grid;
  place-items: center;
  width: 100%;
  height: 100%;
  border-radius: 50%;
  background: #fff;
}
.trust-inner i {
  font-size: calc(var(--trust-size) * 0.34);
  color: #111;
}
.trust-pill {
  height: var(--trust-size);
  display: inline-flex;
  align-items: center;
  background: var(--trust-bg);
  border: 1px solid var(--trust-border);
  border-radius: 999px;
  margin-left: calc(var(--trust-size) * -0.42);
  padding: 0 calc(var(--trust-size) * 0.58);
  font-weight: 500;
  font-size: clamp(12px, 1.4vw, 13.5px);
  color: var(--trust-text);
  white-space: nowrap;
  position: relative;
  z-index: 3;
}

/* Headline */
.headline {
  font-family: var(--font-display);
  font-weight: 400;
  color: var(--text);
  font-size: clamp(28px, 6.2vw, 80px);
  letter-spacing: -0.04em;
  line-height: 1.12;
  white-space: nowrap;
  overflow: hidden;
  margin-bottom: clamp(14px, 2.2vh, 22px);
}
.headline-line {
  display: block;
  opacity: 0;
  transform: translateY(14px);
  animation: headlineFade 0.85s cubic-bezier(0.22, 1, 0.36, 1) forwards;
}
.headline-line.l1 { animation-delay: 0.12s; }
.headline-line.l2 { animation-delay: 0.3s; }
@keyframes headlineFade {
  from { opacity: 0; transform: translateY(14px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Subhead */
.subhead {
  max-width: min(500px, 92%);
  font-size: clamp(calc(13.5px + 2pt), calc(1.55vw + 2pt), calc(16.5px + 2pt));
  color: #d0d0d0;
  opacity: 0.8;
  line-height: 1.55;
  font-weight: 400;
  margin-bottom: clamp(20px, 3.2vh, 30px);
}

/* CTA */
.cta {
  display: inline-block;
  background: #fff;
  color: #000;
  text-decoration: none;
  font-weight: 600;
  font-size: clamp(13.5px, 1.5vw, 14.5px);
  padding: clamp(11px, 1.6vh, 13px) clamp(22px, 3vw, 28px);
  border-radius: 999px;
  box-shadow:
    0 0 0 1px rgba(255, 255, 255, 0.15),
    0 0 22px rgba(255, 255, 255, 0.32),
    0 0 44px rgba(255, 255, 255, 0.12);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.cta:hover {
  transform: translateY(-2px) scale(1.02);
  box-shadow:
    0 0 0 1px rgba(255, 255, 255, 0.25),
    0 0 30px rgba(255, 255, 255, 0.45),
    0 0 60px rgba(255, 255, 255, 0.18);
}

/* ---------------- Shared entrance ---------------- */
.anim {
  opacity: 0;
  transform: translateY(22px) scale(0.98);
  filter: blur(6px);
  animation: reveal 0.85s cubic-bezier(0.22, 1, 0.36, 1) forwards;
  animation-delay: var(--d, 0s);
}
@keyframes reveal {
  from { opacity: 0; transform: translateY(22px) scale(0.98); filter: blur(6px); }
  to { opacity: 1; transform: translateY(0) scale(1); filter: blur(0); }
}
@keyframes revealPulse {
  0% { opacity: 0; transform: translateY(22px) scale(0.98); filter: blur(6px); }
  60% { opacity: 1; transform: translateY(0) scale(1.03); filter: blur(0); }
  100% { opacity: 1; transform: translateY(0) scale(1); filter: blur(0); }
}
.cta.anim { animation-name: revealPulse; }
.headline.anim { animation: none; opacity: 1; transform: none; filter: none; }

/* ---------------- Stats footer ---------------- */
.stats {
  flex-shrink: 0;
  width: 100%;
  max-width: 920px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: clamp(14px, 2.5vw, 28px);
  z-index: 1;
  padding-top: clamp(12px, 2vh, 20px);
}
.stat-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 6px;
}
.stat-icon {
  font-family: var(--font-display);
  font-size: clamp(22px, 3vw, 33px);
  color: var(--text);
  line-height: 1;
}
.stat-value {
  font-weight: 400;
  font-size: clamp(18px, 2.2vw, 26px);
  letter-spacing: -0.025em;
  color: var(--text);
  font-variant-numeric: tabular-nums;
}
.stat-label {
  font-size: clamp(11px, 1.2vw, 12.5px);
  color: var(--muted);
}

/* ---------------- Mobile ≤720px ---------------- */
@media (max-width: 720px) {
  .nav-pill, .sign-in { display: none; }
  .header { justify-content: space-between; }
  .logo { width: 48px; height: 48px; }
  .burger { display: block; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .headline { letter-spacing: -0.08em; line-height: 1.05; }
}

@media (max-width: 420px) {
  .headline { font-size: clamp(28px, 9.4vw, 40px); letter-spacing: -0.09em; line-height: 1.04; }
  .trust-row { --trust-size: 34px; }
  .trust-pill { font-size: 12px; }
}

@media (max-height: 700px) {
  .hero { justify-content: center; }
  .trust-row { margin-bottom: 14px; }
  .headline { margin-bottom: 12px; }
  .subhead { margin-bottom: 16px; }
}

/* ---------------- Reduced motion ---------------- */
@media (prefers-reduced-motion: reduce) {
  .anim, .headline-line, .header, .mobile-menu, .m-link, .m-signin, .overlay {
    animation: none !important;
    opacity: 1 !important;
    transform: none !important;
    filter: none !important;
  }
  .headline { color: #fff; }
  .bg-video { display: none; }
  .bg { background: #000; }
}

/* hidden 属性必须真正隐藏(CSS display 会覆盖 UA 样式) */
.mobile-menu[hidden] { display: none !important; }
.overlay[hidden] { display: none !important; }