:root {
  --primary: #2f6bff;
  --primary-2: #7b5cff;
  --text: #141a2e;
  --muted: #5d6680;
  --line: #e6e9f2;
  --bg-alt: #f5f7fc;
  --radius: 18px;
  --shadow: 0 18px 50px rgba(31, 52, 120, 0.12);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: 72px; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
  color: var(--text);
  background: #fff;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
img { display: block; }
[hidden] { display: none !important; }

.container { width: min(1120px, 100% - 40px); margin: 0 auto; }
.container.narrow { width: min(760px, 100% - 40px); }

/* 顶部导航 */
.header {
  position: sticky; top: 0; z-index: 10;
  background: rgba(255, 255, 255, 0.86);
  backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--line);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 20px; }
.brand img { width: 34px; height: 34px; border-radius: 9px; }
.brand.small { font-size: 16px; }
.brand.small img { width: 26px; height: 26px; border-radius: 7px; }
.nav { display: flex; align-items: center; gap: 28px; font-size: 15px; color: var(--muted); }
.nav a:hover { color: var(--primary); }
.nav .nav-cta { color: #fff; background: var(--primary); padding: 8px 18px; border-radius: 999px; }
.nav .nav-cta:hover { color: #fff; opacity: 0.9; }
.nav-toggle { display: none; background: none; border: 0; width: 36px; height: 36px; cursor: pointer; }
.nav-toggle span { display: block; height: 2px; margin: 7px 6px; background: var(--text); border-radius: 2px; }

/* 首屏 */
.hero {
  padding: 72px 0 88px;
  background:
    radial-gradient(600px 360px at 85% 10%, rgba(123, 92, 255, 0.16), transparent 70%),
    radial-gradient(520px 320px at 10% 90%, rgba(47, 107, 255, 0.14), transparent 70%);
}
.hero-inner { display: grid; grid-template-columns: 1.1fr 0.9fr; align-items: center; gap: 48px; }
.eyebrow { color: var(--primary); font-weight: 600; letter-spacing: 0.08em; font-size: 14px; }
.hero h1 { font-size: clamp(36px, 5.4vw, 60px); line-height: 1.15; margin: 14px 0 18px; }
.gradient {
  background: linear-gradient(90deg, var(--primary), var(--primary-2));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.lead { font-size: 18px; color: var(--muted); max-width: 520px; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 30px; }
.actions.center { justify-content: center; }
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  height: 50px; padding: 0 26px; border-radius: 999px;
  font-weight: 600; font-size: 16px; transition: transform 0.2s, box-shadow 0.2s;
}
.btn:hover { transform: translateY(-2px); }
.btn.primary { color: #fff; background: linear-gradient(90deg, var(--primary), var(--primary-2)); box-shadow: 0 10px 26px rgba(47, 107, 255, 0.32); }
.btn.ghost { color: var(--primary); background: #fff; border: 1.5px solid rgba(47, 107, 255, 0.35); }
.btn.light { color: var(--primary); background: #fff; }
.btn.outline { color: #fff; border: 1.5px solid rgba(255, 255, 255, 0.7); }
.hero-points { list-style: none; display: flex; flex-wrap: wrap; gap: 10px 22px; margin-top: 28px; color: var(--muted); font-size: 15px; }
.hero-points li::before { content: ""; display: inline-block; width: 8px; height: 8px; margin-right: 8px; border-radius: 50%; background: var(--primary); }

/* 首屏手机示意 */
.phone {
  justify-self: center; width: 320px; padding: 16px 14px 14px;
  border-radius: 38px; background: #f4f6fb;
  border: 8px solid #10131f; box-shadow: var(--shadow);
  display: flex; flex-direction: column; gap: 10px;
  animation: float 6s ease-in-out infinite;
}
.phone-top { display: flex; justify-content: space-between; align-items: baseline; padding: 4px 6px 8px; border-bottom: 1px solid var(--line); }
.phone-top small { color: var(--muted); }
.pin-bar { font-size: 12px; color: var(--primary); background: #e9efff; border-radius: 10px; padding: 6px 10px; }
.bubble { max-width: 82%; padding: 9px 13px; border-radius: 16px; font-size: 14px; background: #fff; box-shadow: 0 2px 6px rgba(0, 0, 0, 0.05); }
.bubble.in { align-self: flex-start; border-top-left-radius: 6px; }
.bubble.out { align-self: flex-end; color: #fff; background: var(--primary); border-top-right-radius: 6px; }
.bubble.out i { display: block; text-align: right; font-style: normal; font-size: 11px; opacity: 0.8; }
.bubble.quote em { display: block; font-style: normal; font-size: 12px; color: var(--muted); border-left: 3px solid var(--primary); padding-left: 7px; margin-bottom: 4px; }
.bubble.redpacket { align-self: flex-start; color: #fff; background: linear-gradient(135deg, #ff6a4a, #f2453d); width: 190px; }
.bubble.redpacket small { display: block; opacity: 0.85; font-size: 12px; border-top: 1px solid rgba(255, 255, 255, 0.3); margin-top: 8px; padding-top: 4px; }
.bubble.voice { display: flex; align-items: center; gap: 10px; }
.wave { width: 70px; height: 14px; background: repeating-linear-gradient(90deg, #fff 0 3px, transparent 3px 7px); border-radius: 3px; opacity: 0.9; }
.phone-input { display: flex; align-items: center; justify-content: space-between; margin-top: 4px; padding: 9px 12px; border-radius: 999px; background: #fff; color: #a3aac0; font-size: 13px; }
.phone-input i { width: 24px; height: 24px; border-radius: 50%; background: var(--primary); }

/* 通用区块 */
.section { padding: 96px 0; }
.section.alt { background: var(--bg-alt); }
.title { font-size: clamp(28px, 3.6vw, 40px); text-align: center; line-height: 1.25; }
.subtitle { text-align: center; color: var(--muted); font-size: 17px; margin: 12px auto 52px; max-width: 620px; }
.title.left, .subtitle.left { text-align: left; margin-left: 0; }
.grid { display: grid; gap: 22px; }
.grid.three { grid-template-columns: repeat(3, 1fr); }
.grid.four { grid-template-columns: repeat(4, 1fr); }
.card, .mini {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 28px; transition: transform 0.25s, box-shadow 0.25s;
}
.card:hover, .mini:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.card svg, .mini svg {
  width: 46px; height: 46px; padding: 11px; border-radius: 14px;
  fill: none; stroke: var(--primary); stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round;
  background: #eef3ff; margin-bottom: 18px;
}
.card h3 { font-size: 19px; margin-bottom: 8px; }
.mini h4 { font-size: 17px; margin-bottom: 6px; }
.card p, .mini p { color: var(--muted); font-size: 15px; }

/* 聊天细节 */
.split { display: grid; grid-template-columns: 0.8fr 1.2fr; gap: 56px; align-items: start; }
.split > div { position: sticky; top: 110px; }
.detail-list { list-style: none; display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.detail-list li { background: #fff; border-radius: 16px; padding: 22px; border: 1px solid var(--line); }
.detail-list b { display: block; font-size: 16px; margin-bottom: 6px; }
.detail-list span { color: var(--muted); font-size: 14px; }

/* 多端 */
.platforms { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.platform { background: #fff; border-radius: 16px; padding: 26px 22px; text-align: center; border: 1px solid var(--line); }
.platform b { display: block; font-size: 20px; margin-bottom: 6px; }
.platform span { color: var(--muted); font-size: 14px; }
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; margin-top: 40px; padding: 30px; border-radius: var(--radius); color: #fff; background: linear-gradient(120deg, var(--primary), var(--primary-2)); }
.stats b { display: block; font-size: 20px; }
.stats span { font-size: 14px; opacity: 0.88; }

/* 常见问题 */
.narrow .title { margin-bottom: 32px; }
.faq-item { border-bottom: 1px solid var(--line); }
.faq-item button {
  width: 100%; text-align: left; background: none; border: 0; cursor: pointer;
  font: inherit; font-size: 17px; font-weight: 600; color: var(--text);
  padding: 22px 36px 22px 0; position: relative;
}
.faq-item button::after { content: "+"; position: absolute; right: 4px; top: 18px; font-size: 24px; color: var(--primary); transition: transform 0.2s; }
.faq-item.open button::after { transform: rotate(45deg); }
.faq-item p { display: none; color: var(--muted); padding: 0 0 22px; }
.faq-item.open p { display: block; }

/* 底部号召与页脚 */
.cta { padding: 96px 0; }
.cta-inner { text-align: center; color: #fff; padding: 64px 24px; border-radius: 28px; background: linear-gradient(120deg, var(--primary), var(--primary-2)); box-shadow: var(--shadow); }
.cta h2 { font-size: clamp(26px, 3.4vw, 36px); }
.cta p { opacity: 0.88; margin-top: 10px; }
.footer { border-top: 1px solid var(--line); padding: 32px 0; color: var(--muted); font-size: 14px; }
.footer-inner { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 12px; }

/* 进入视口渐显 */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity 0.6s ease, transform 0.6s ease; }
.reveal.shown { opacity: 1; transform: none; }
@keyframes float { 50% { transform: translateY(-10px); } }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  .phone { animation: none; }
}

/* 平板 */
@media (max-width: 960px) {
  .hero-inner, .split { grid-template-columns: 1fr; }
  .split > div { position: static; }
  .hero-text { text-align: center; }
  .lead { margin: 0 auto; }
  .actions, .hero-points { justify-content: center; }
  .title.left, .subtitle.left { text-align: center; margin-left: auto; }
  .grid.three, .grid.four, .platforms, .stats { grid-template-columns: repeat(2, 1fr); }
}

/* 手机 */
@media (max-width: 640px) {
  .nav-toggle { display: block; }
  .nav {
    display: none; position: absolute; top: 64px; left: 0; right: 0;
    flex-direction: column; gap: 0; padding: 8px 20px 16px;
    background: #fff; border-bottom: 1px solid var(--line);
  }
  .nav.open { display: flex; }
  .nav a { width: 100%; padding: 12px 0; }
  .nav .nav-cta { text-align: center; margin-top: 8px; }
  .hero { padding: 44px 0 64px; }
  .section, .cta { padding: 64px 0; }
  .grid.three, .grid.four, .platforms, .detail-list { grid-template-columns: 1fr; }
  .stats { grid-template-columns: 1fr 1fr; padding: 22px; }
  .phone { width: 290px; }
  .btn { flex: 1 1 100%; }
  .footer-inner { flex-direction: column; text-align: center; }
}