:root {
  --blue: #4c94ff;
  --blue-2: #3a7fe6;
  --ink: #1f2a37;
  --muted: #667085;
  --line: #e8eef6;
  --paper: #f4f7fc;
  --spring: cubic-bezier(.34, 1.45, .48, 1);
  --phone: #d8cfe6;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: #fff;
  font: 16px/1.75 "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
.wrap { width: min(1180px, calc(100% - 40px)); margin: 0 auto; }

.nav {
  position: sticky; top: 0; z-index: 20;
  background: rgba(255,255,255,.82);
  backdrop-filter: blur(18px);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.brand { display: flex; align-items: center; gap: 10px; }
.brand img { width: 38px; height: 38px; border-radius: 14px; box-shadow: 0 8px 18px rgba(76,148,255,.28); }
.brand b { font-size: 20px; letter-spacing: .16em; }
.nav nav a {
  margin-left: 8px;
  padding: 8px 16px;
  border-radius: 999px;
  color: var(--muted);
  font-size: 14px;
}
.nav nav a.on, .nav nav a:hover { color: var(--blue); background: #eef5ff; }

.hero {
  position: relative;
  background:
    radial-gradient(circle at 18% 20%, rgba(255,255,255,.28), transparent 26%),
    radial-gradient(circle at 86% 10%, rgba(255,210,255,.22), transparent 24%),
    linear-gradient(160deg, #6aa8ff 0%, #4c94ff 46%, #3a72f0 100%);
  color: #fff;
  padding: 48px 0 0;
  overflow: hidden;
}
.hero::after {
  content: "";
  display: block;
  height: 72px;
  background: #fff;
  border-radius: 48px 48px 0 0;
  margin-top: 8px;
}
.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1.15fr;
  gap: 12px;
  align-items: center;
  min-height: 600px;
}
.kicker {
  display: inline-flex;
  padding: 6px 14px;
  border-radius: 999px;
  background: rgba(255,255,255,.18);
  letter-spacing: .28em;
  font-size: 12px;
}
h1, h2, h3 { font-weight: 700; margin: 0; }
h1 { font-size: clamp(52px, 7vw, 86px); line-height: 1.02; margin: 18px 0 16px; letter-spacing: .1em; }
h2 { font-size: 32px; margin: 0 0 12px; }
h3 { font-size: 20px; margin: 0 0 8px; }
.lead { max-width: 520px; font-size: 18px; line-height: 1.7; opacity: .94; }
.hero .lead { color: #fff; }
.hero.doc {
  background: #fff;
  color: var(--ink);
  padding: 48px 0 80px;
}
.hero.doc::after { display: none; }
.hero.doc .lead, .hero.doc p { color: var(--muted); }
.hero.doc h2 { margin: 28px 0 10px; font-size: 24px; }
.prose { max-width: 760px; }
.prose a { color: var(--blue); }

.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 28px; }
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-width: 148px; height: 50px; padding: 0 22px;
  border-radius: 999px; font-weight: 600;
  box-shadow: 0 10px 24px rgba(16, 42, 86, .12);
}
.btn.apk, .btn.ios { background: #fff; color: var(--blue); }
.btn.ghost { background: rgba(255,255,255,.12); color: #fff; border: 1px solid rgba(255,255,255,.55); box-shadow: none; }
.band .btn.apk, .band .btn.ios,
.hero.doc .btn.apk, .hero.doc .btn.ios { background: var(--blue); color: #fff; }
.band .btn.ghost, .hero.doc .btn.ghost { color: var(--ink); border: 1px solid #d7e0ee; background: #fff; }

.stage {
  position: relative;
  height: 620px;
  perspective: 1400px;
}
.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(2px);
  pointer-events: none;
}
.orb.o1 { width: 220px; height: 220px; left: 8%; top: 40px; background: radial-gradient(circle at 30% 30%, #fff, rgba(255,255,255,0)); opacity: .28; }
.orb.o2 { width: 160px; height: 160px; right: 6%; bottom: 90px; background: radial-gradient(circle at 30% 30%, #ffd6f5, rgba(255,210,255,0)); opacity: .45; }

.phones {
  position: absolute;
  inset: 0;
  transform-style: preserve-3d;
  transition: transform .18s ease-out;
}
.phone {
  position: absolute;
  width: 236px;
  padding: 12px 8px 10px;
  background:
    linear-gradient(145deg, #f6f2fb 0%, #ddd4ea 42%, #c4bad6 100%);
  border-radius: 36px;
  border: 1px solid rgba(255,255,255,.65);
  box-shadow:
    inset 0 1px 1px #fff,
    inset 0 -3px 6px rgba(70, 55, 100, .12),
    10px 16px 0 -5px #b4a8c8,
    18px 30px 40px rgba(40, 28, 70, .25);
  transform-style: preserve-3d;
}
.phone::before {
  content: "";
  position: absolute;
  left: 50%; top: 6px;
  width: 72px; height: 6px;
  margin-left: -36px;
  background: #1a1a22;
  border-radius: 6px;
  z-index: 2;
}
.phone img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 26px;
  background: #fff;
}
.phones .p-main {
  left: 50%; top: 28px;
  margin-left: -118px;
  z-index: 3;
  transform: rotateY(-12deg) rotateX(8deg) translateZ(50px);
}
.phones .p-side {
  width: 196px;
  top: 78px;
  z-index: 1;
  opacity: .92;
}
.phones .p-side.left {
  left: 4%;
  transform: rotateY(28deg) rotateX(10deg) translateZ(-40px);
}
.phones .p-side.right {
  right: 2%;
  transform: rotateY(-32deg) rotateX(10deg) translateZ(-70px);
}

.bubbles span {
  position: absolute;
  background: rgba(255,255,255,.18);
  backdrop-filter: blur(10px);
  color: #fff;
  border: 1px solid rgba(255,255,255,.28);
  border-radius: 999px;
  padding: 8px 16px;
  font-size: 13px;
  white-space: nowrap;
  box-shadow: 0 10px 22px rgba(16, 42, 86, .16);
  z-index: 4;
}
.bubbles .b1 { left: 0; top: 58px; }
.bubbles .b2 { left: -8px; top: 210px; }
.bubbles .b3 { left: 18px; top: 370px; }
.bubbles .b4 { right: 0; top: 42px; }
.bubbles .b5 { right: -6px; top: 188px; }
.bubbles .b6 { right: 10px; top: 340px; }
.bubbles .b7 { left: 50%; bottom: 78px; transform: translateX(-50%); }

.band { padding: 36px 0 80px; }
.band.alt { background: var(--paper); }
.sec-k { color: var(--blue); letter-spacing: .28em; font-size: 12px; margin-bottom: 10px; }

.ports {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 28px;
}
.port {
  background: #fff;
  border: 1px solid transparent;
  border-radius: 28px;
  padding: 32px 26px;
  box-shadow: 0 16px 40px rgba(31, 55, 99, .08);
}
.port em {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 64px;
  height: 32px;
  padding: 0 12px;
  border-radius: 999px;
  background: #eef5ff;
  color: var(--blue);
  font-style: normal;
  font-size: 13px;
  letter-spacing: .12em;
  margin-bottom: 14px;
}
.port p { color: var(--muted); margin: 8px 0 18px; }

.film {
  display: flex;
  justify-content: center;
  gap: 28px;
  margin-top: 28px;
  padding: 20px 0 36px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  perspective: 1200px;
}
.frame {
  flex: 0 0 200px;
  margin: 0;
  text-align: center;
  scroll-snap-align: center;
}
.frame .phone {
  position: relative;
  width: 100%;
  left: auto;
  top: auto;
  margin: 0;
}
.frame:nth-child(1) .phone { transform: rotateY(14deg) rotateX(6deg) translateZ(8px); }
.frame:nth-child(2) .phone { transform: rotateY(5deg) rotateX(6deg) translateZ(16px); }
.frame:nth-child(3) .phone { transform: rotateY(-5deg) rotateX(6deg) translateZ(16px); }
.frame:nth-child(4) .phone { transform: rotateY(-14deg) rotateX(6deg) translateZ(8px); }
.frame figcaption { margin-top: 16px; color: var(--muted); letter-spacing: .16em; font-size: 13px; }

.timeline { margin-top: 28px; display: grid; gap: 12px; }
.tl {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 18px;
  padding: 18px 22px;
  background: #fff;
  border-radius: 20px;
  box-shadow: 0 10px 28px rgba(31, 55, 99, .06);
}
.tl b { color: var(--blue); letter-spacing: .16em; }
.essay { max-width: 760px; }
.essay p { color: var(--muted); }
.faq details {
  background: #fff;
  border: 0;
  border-radius: 18px;
  padding: 16px 20px;
  margin: 10px 0;
  box-shadow: 0 10px 28px rgba(31, 55, 99, .06);
}
.faq summary { cursor: pointer; font-size: 17px; }
.faq details p { color: var(--muted); }
.related { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.related a {
  display: block;
  padding: 24px;
  border-radius: 24px;
  background: var(--paper);
  box-shadow: 0 12px 30px rgba(31, 55, 99, .06);
}
.related small { color: var(--blue); letter-spacing: .16em; }
.foot {
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px;
  padding: 28px 0 40px; color: var(--muted); font-size: 13px;
}
.ios-steps { counter-reset: step; padding: 0; }
.ios-steps li {
  list-style: none;
  position: relative;
  padding: 16px 18px 16px 58px;
  margin: 10px 0;
  border-radius: 18px;
  background: var(--paper);
}
.ios-steps li::before {
  counter-increment: step;
  content: counter(step);
  position: absolute; left: 16px; top: 16px;
  width: 28px; height: 28px;
  border-radius: 50%;
  background: var(--blue); color: #fff;
  text-align: center; line-height: 28px; font-size: 13px;
}
.wx-mask {
  display: none; position: fixed; inset: 0; z-index: 50;
  background: rgba(16, 24, 40, .72); color: #fff;
  align-items: flex-start; justify-content: flex-end; padding: 22px;
}
.wx-mask.on { display: flex; }

@media (max-width: 980px) {
  .hero-grid, .ports, .related { grid-template-columns: 1fr; }
  .hero-grid { min-height: 0; }
  .stage { height: 520px; perspective: none; }
  .phones .p-side { display: none; }
  .phones .p-main { width: 210px; margin-left: -105px; transform: none; }
  .bubbles .b3, .bubbles .b6 { display: none; }
  .film { justify-content: flex-start; padding-left: 8px; }
  .tl { grid-template-columns: 1fr; }
}