/* ============ 基础 ============ */
:root {
  --primary: #3b82f6;
  --primary-dark: #2563eb;
  --accent: #8b5cf6;
  --gradient: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%);
  --text: #1e293b;
  --text-light: #64748b;
  --bg: #ffffff;
  --bg-soft: #f6f8fc;
  --border: #e2e8f0;
  --radius: 16px;
  --shadow: 0 8px 30px rgba(30, 64, 175, 0.08);
  --shadow-lg: 0 20px 60px rgba(59, 130, 246, 0.18);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  overflow-x: hidden;
}

.container { max-width: 1180px; margin: 0 auto; padding: 0 24px; }

a { text-decoration: none; color: inherit; }

/* ============ 按钮 ============ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.25s ease;
  border: none;
}
.btn-primary {
  background: var(--gradient);
  color: #fff;
  box-shadow: 0 6px 20px rgba(99, 102, 241, 0.35);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 10px 28px rgba(99, 102, 241, 0.45); }
.btn-ghost {
  background: rgba(255, 255, 255, 0.15);
  color: var(--text);
  border: 1.5px solid var(--border);
  backdrop-filter: blur(6px);
}
.btn-ghost:hover { border-color: var(--primary); color: var(--primary); }
.btn-lg { padding: 14px 36px; font-size: 16px; }
.btn-sm { padding: 8px 20px; font-size: 14px; }

/* ============ 导航栏 ============ */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: all 0.3s ease;
}
.navbar.scrolled { border-bottom-color: var(--border); box-shadow: 0 2px 20px rgba(0,0,0,0.05); }
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.logo { display: flex; align-items: center; gap: 10px; }
.logo-icon { display: flex; }
.logo-text { font-size: 22px; font-weight: 700; background: var(--gradient); -webkit-background-clip: text; background-clip: text; color: transparent; }
.nav-links { display: flex; gap: 34px; }
.nav-links a { font-size: 15px; color: var(--text-light); font-weight: 500; transition: color 0.2s; position: relative; }
.nav-links a:hover, .nav-links a.active { color: var(--primary); }
.nav-links a::after {
  content: ""; position: absolute; left: 0; bottom: -6px;
  width: 0; height: 2px; background: var(--gradient); border-radius: 2px; transition: width 0.25s;
}
.nav-links a:hover::after, .nav-links a.active::after { width: 100%; }
.nav-actions { display: flex; align-items: center; gap: 14px; }
.menu-toggle { display: none; background: none; border: none; cursor: pointer; padding: 6px; }
.menu-toggle span { display: block; width: 22px; height: 2px; background: var(--text); margin: 5px 0; border-radius: 2px; transition: all 0.3s; }

/* ============ Hero ============ */
.hero {
  position: relative;
  padding: 160px 0 100px;
  overflow: hidden;
}
.hero-bg {
  position: absolute; inset: 0;
  background:
    radial-gradient(ellipse 60% 50% at 15% 20%, rgba(59, 130, 246, 0.12), transparent),
    radial-gradient(ellipse 50% 40% at 85% 30%, rgba(139, 92, 246, 0.12), transparent),
    linear-gradient(180deg, #fbfcff 0%, #ffffff 100%);
  z-index: -1;
}
.hero-inner { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 50px; align-items: center; }
.hero-badge {
  display: inline-block;
  padding: 6px 18px;
  border-radius: 999px;
  background: rgba(59, 130, 246, 0.08);
  border: 1px solid rgba(59, 130, 246, 0.2);
  color: var(--primary-dark);
  font-size: 14px;
  font-weight: 500;
  margin-bottom: 22px;
}
.hero h1 { font-size: 56px; line-height: 1.2; font-weight: 800; letter-spacing: 1px; }
.gradient-text { background: var(--gradient); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero-sub { margin: 22px 0 34px; font-size: 17px; color: var(--text-light); max-width: 520px; }
.hero-btns { display: flex; gap: 16px; flex-wrap: wrap; }
.hero-stats { display: flex; gap: 46px; margin-top: 50px; }
.stat b { display: block; font-size: 30px; font-weight: 800; background: var(--gradient); -webkit-background-clip: text; background-clip: text; color: transparent; }
.stat span { font-size: 13px; color: var(--text-light); }

/* 手机模型 */
.hero-phone { position: relative; display: flex; justify-content: center; }
.phone-mockup {
  width: 300px;
  height: 610px;
  background: #0f172a;
  border-radius: 42px;
  padding: 12px;
  box-shadow: var(--shadow-lg), 0 0 0 2px rgba(255,255,255,0.6) inset;
  position: relative;
  animation: phoneFloat 5s ease-in-out infinite;
}
@keyframes phoneFloat {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-14px); }
}
.phone-notch {
  position: absolute; top: 12px; left: 50%; transform: translateX(-50%);
  width: 110px; height: 26px; background: #0f172a; border-radius: 0 0 16px 16px; z-index: 2;
}
.phone-screen {
  width: 100%; height: 100%;
  background: linear-gradient(180deg, #eef3fb 0%, #f8fafc 100%);
  border-radius: 32px;
  overflow: hidden;
  display: flex; flex-direction: column;
}
.chat-header {
  display: flex; align-items: center; gap: 10px;
  padding: 34px 16px 12px;
  background: var(--gradient);
  color: #fff;
}
.chat-avatar { width: 34px; height: 34px; border-radius: 50%; background: rgba(255,255,255,0.3); flex-shrink: 0; }
.chat-title { flex: 1; }
.chat-title b { display: block; font-size: 14px; line-height: 1.3; }
.chat-title i { font-style: normal; font-size: 11px; opacity: 0.8; }
.chat-more { font-size: 18px; opacity: 0.9; }
.chat-body { flex: 1; padding: 14px 12px; display: flex; flex-direction: column; gap: 12px; overflow: hidden; }
.msg { display: flex; gap: 8px; max-width: 85%; animation: msgIn 0.5s ease backwards; }
.msg:nth-child(1) { animation-delay: 0.3s; }
.msg:nth-child(2) { animation-delay: 0.6s; }
.msg:nth-child(3) { animation-delay: 0.9s; }
.msg:nth-child(4) { animation-delay: 1.2s; }
.msg:nth-child(5) { animation-delay: 1.5s; }
@keyframes msgIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}
.msg-right { align-self: flex-end; }
.msg-avatar { width: 28px; height: 28px; border-radius: 50%; flex-shrink: 0; }
.a1 { background: linear-gradient(135deg, #fbbf24, #f59e0b); }
.a2 { background: linear-gradient(135deg, #34d399, #10b981); }
.a3 { background: linear-gradient(135deg, #f87171, #ef4444); }
.bubble {
  padding: 9px 13px;
  border-radius: 4px 14px 14px 14px;
  background: #fff;
  font-size: 13px;
  color: var(--text);
  box-shadow: 0 2px 8px rgba(0,0,0,0.06);
  line-height: 1.5;
}
.msg-right .bubble {
  background: var(--gradient);
  color: #fff;
  border-radius: 14px 4px 14px 14px;
}
.bubble.voice { display: flex; align-items: center; gap: 6px; min-width: 70px; }
.voice-wave { font-style: normal; color: var(--primary); letter-spacing: -1px; }
.chat-input {
  display: flex; align-items: center; gap: 10px;
  padding: 10px 14px 18px;
  background: #fff;
  border-top: 1px solid var(--border);
}
.input-box { flex: 1; background: var(--bg-soft); border-radius: 999px; padding: 8px 14px; font-size: 12px; color: #94a3b8; }
.input-emoji, .input-plus { font-size: 18px; color: var(--text-light); }

.float-card {
  position: absolute;
  padding: 10px 18px;
  background: #fff;
  border-radius: 12px;
  box-shadow: var(--shadow);
  font-size: 13px;
  font-weight: 600;
  animation: cardFloat 4s ease-in-out infinite;
}
.card-1 { top: 90px; left: -10px; animation-delay: 0.5s; }
.card-2 { bottom: 110px; right: -10px; animation-delay: 1.5s; }
@keyframes cardFloat {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

/* ============ 通用 Section ============ */
.section { padding: 100px 0; }
.section-head { text-align: center; max-width: 640px; margin: 0 auto 60px; }
.section-tag {
  display: inline-block;
  padding: 4px 16px;
  border-radius: 999px;
  background: rgba(59, 130, 246, 0.08);
  color: var(--primary-dark);
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 16px;
}
.section-head h2, .security-text h2, .about h2 { font-size: 36px; font-weight: 800; line-height: 1.3; }
.section-head p { margin-top: 14px; color: var(--text-light); font-size: 16px; }

/* ============ 功能 ============ */
.features { background: var(--bg-soft); }
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 26px; }
.feature-card {
  background: #fff;
  border-radius: var(--radius);
  padding: 36px 30px;
  border: 1px solid var(--border);
  transition: all 0.3s ease;
}
.feature-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); border-color: transparent; }
.feature-icon {
  width: 60px; height: 60px;
  border-radius: 16px;
  display: flex; align-items: center; justify-content: center;
  font-size: 28px;
  margin-bottom: 22px;
}
.fi-1 { background: rgba(59, 130, 246, 0.1); }
.fi-2 { background: rgba(139, 92, 246, 0.1); }
.fi-3 { background: rgba(236, 72, 153, 0.1); }
.fi-4 { background: rgba(245, 158, 11, 0.1); }
.fi-5 { background: rgba(16, 185, 129, 0.1); }
.fi-6 { background: rgba(6, 182, 212, 0.1); }
.feature-card h3 { font-size: 19px; font-weight: 700; margin-bottom: 10px; }
.feature-card p { font-size: 14.5px; color: var(--text-light); }

/* ============ 安全 ============ */
.security-inner { display: grid; grid-template-columns: 0.9fr 1.1fr; gap: 60px; align-items: center; }
.security-visual { display: flex; justify-content: center; }
.shield { position: relative; width: 320px; height: 320px; display: flex; align-items: center; justify-content: center; }
.shield-ring {
  position: absolute; border-radius: 50%;
  border: 1.5px solid rgba(59, 130, 246, 0.25);
  animation: ringPulse 3s ease-in-out infinite;
}
.r1 { width: 140px; height: 140px; }
.r2 { width: 220px; height: 220px; animation-delay: 0.6s; border-color: rgba(139, 92, 246, 0.2); }
.r3 { width: 300px; height: 300px; animation-delay: 1.2s; border-color: rgba(59, 130, 246, 0.12); }
@keyframes ringPulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.06); opacity: 0.6; }
}
.shield-core {
  width: 90px; height: 90px;
  border-radius: 50%;
  background: var(--gradient);
  display: flex; align-items: center; justify-content: center;
  font-size: 42px;
  box-shadow: 0 12px 40px rgba(99, 102, 241, 0.4);
}
.security-list { margin-top: 30px; display: flex; flex-direction: column; gap: 22px; }
.security-list li { list-style: none; display: flex; flex-direction: column; }
.security-list b { font-size: 16.5px; margin-bottom: 4px; }
.security-list span { font-size: 14.5px; color: var(--text-light); }

/* ============ 下载 ============ */
.download { background: var(--bg-soft); }
.download-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.dl-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 34px 24px;
  text-align: center;
  transition: all 0.3s ease;
  display: flex; flex-direction: column; align-items: center; gap: 8px;
}
.dl-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); border-color: var(--primary); }
.dl-icon {
  width: 64px; height: 64px;
  border-radius: 18px;
  background: var(--gradient);
  color: #fff;
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 8px;
}
.dl-card h3 { font-size: 18px; font-weight: 700; }
.dl-card p { font-size: 13px; color: var(--text-light); }
.dl-btn {
  margin-top: 10px;
  padding: 8px 22px;
  border-radius: 999px;
  background: rgba(59, 130, 246, 0.08);
  color: var(--primary-dark);
  font-size: 13.5px;
  font-weight: 600;
  transition: all 0.25s;
}
.dl-card:hover .dl-btn { background: var(--gradient); color: #fff; }

/* ============ 关于 ============ */
.about-inner { text-align: center; max-width: 860px; }
.about-desc { margin: 24px auto 0; color: var(--text-light); font-size: 16px; text-align: left; text-indent: 2em; }
.about-values { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; margin-top: 50px; }
.value {
  padding: 28px 22px;
  border-radius: var(--radius);
  background: var(--bg-soft);
  border: 1px solid var(--border);
}
.value b { display: block; font-size: 18px; margin-bottom: 8px; background: var(--gradient); -webkit-background-clip: text; background-clip: text; color: transparent; }
.value span { font-size: 14px; color: var(--text-light); }

/* ============ 页脚 ============ */
.footer { background: #0f172a; color: #94a3b8; }
.footer-inner {
  display: grid;
  grid-template-columns: 1.4fr repeat(4, 1fr);
  gap: 40px;
  padding: 70px 24px 50px;
}
.footer .logo-text { background: linear-gradient(135deg, #60a5fa, #a78bfa); -webkit-background-clip: text; background-clip: text; }
.footer-brand p { margin-top: 16px; font-size: 14px; line-height: 1.8; }
.footer-col h4 { color: #f1f5f9; font-size: 15px; margin-bottom: 18px; }
.footer-col a, .contact-item { display: block; font-size: 14px; margin-bottom: 10px; transition: color 0.2s; }
.footer-col a:hover { color: #60a5fa; }
.footer-bottom { border-top: 1px solid rgba(148, 163, 184, 0.15); padding: 22px 0; }
.footer-bottom .container { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 8px; }
.footer-bottom p { font-size: 13px; }
.footer-bottom a:hover { color: #60a5fa; }

/* ============ 返回顶部 ============ */
.back-top {
  position: fixed;
  right: 28px; bottom: 28px;
  width: 46px; height: 46px;
  border-radius: 50%;
  background: var(--gradient);
  color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 20px;
  box-shadow: var(--shadow-lg);
  opacity: 0; pointer-events: none;
  transform: translateY(10px);
  transition: all 0.3s ease;
  z-index: 999;
}
.back-top.show { opacity: 1; pointer-events: auto; transform: translateY(0); }

/* ============ 滚动动画 ============ */
[data-animate] { opacity: 0; transform: translateY(28px); transition: opacity 0.7s ease, transform 0.7s ease; }
[data-animate].visible { opacity: 1; transform: translateY(0); }

/* ============ 响应式 ============ */
@media (max-width: 1024px) {
  .hero-inner { grid-template-columns: 1fr; text-align: center; }
  .hero-sub { margin-left: auto; margin-right: auto; }
  .hero-btns, .hero-stats { justify-content: center; }
  .hero-phone { margin-top: 30px; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .download-grid { grid-template-columns: repeat(2, 1fr); }
  .security-inner { grid-template-columns: 1fr; }
  .security-text { text-align: center; }
  .security-list { text-align: left; max-width: 560px; margin-left: auto; margin-right: auto; }
  .footer-inner { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: 68px; left: 0; right: 0;
    background: #fff;
    flex-direction: column;
    gap: 0;
    padding: 10px 0;
    box-shadow: 0 10px 30px rgba(0,0,0,0.08);
    transform: translateY(-130%);
    transition: transform 0.35s ease;
    z-index: 998;
  }
  .nav-links.open { transform: translateY(0); }
  .nav-links a { padding: 13px 28px; }
  .menu-toggle { display: block; }
  .nav-actions .btn { display: none; }
  .hero { padding: 130px 0 70px; }
  .hero h1 { font-size: 38px; }
  .hero-stats { gap: 26px; flex-wrap: wrap; }
  .section { padding: 70px 0; }
  .section-head h2, .security-text h2, .about h2 { font-size: 28px; }
  .feature-grid { grid-template-columns: 1fr; }
  .download-grid { grid-template-columns: 1fr; }
  .about-values { grid-template-columns: 1fr; }
  .about-desc { text-indent: 0; }
  .phone-mockup { width: 260px; height: 530px; }
  .float-card { display: none; }
  .footer-inner { grid-template-columns: 1fr; gap: 28px; padding: 50px 24px 34px; }
  .footer-bottom .container { flex-direction: column; text-align: center; }
}