:root {
  --bg: #0b0f1a;
  --bg-soft: #121829;
  --surface: rgba(255, 255, 255, 0.04);
  --surface-2: rgba(255, 255, 255, 0.07);
  --border: rgba(255, 255, 255, 0.10);
  --text: #eef2ff;
  --muted: #9aa6c4;
  --brand: #6366f1;
  --brand-2: #22d3ee;
  --accent: #a78bfa;
  --radius: 18px;
  --shadow: 0 20px 60px rgba(0, 0, 0, 0.45);
  --grad: linear-gradient(135deg, #6366f1 0%, #22d3ee 100%);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", Roboto, Helvetica, Arial, sans-serif;
  background: radial-gradient(1200px 600px at 80% -10%, rgba(99, 102, 241, 0.25), transparent 60%),
    radial-gradient(900px 500px at 0% 10%, rgba(34, 211, 238, 0.18), transparent 55%),
    var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

.container { width: min(1120px, 92vw); margin: 0 auto; }

/* ===== 导航 ===== */
.nav {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: blur(14px);
  background: rgba(11, 15, 26, 0.6);
  border-bottom: 1px solid transparent;
  transition: border-color .25s, background .25s;
}
.nav.is-scrolled { border-color: var(--border); background: rgba(11, 15, 26, 0.85); }
.nav__inner { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; }
.brand__logo { display: inline-flex; }
.brand__name { font-size: 1.15rem; letter-spacing: .5px; }
.brand__name small { font-weight: 600; color: var(--muted); font-size: .72rem; letter-spacing: 1px; }
.nav__links { display: flex; gap: 28px; }
.nav__links a { color: var(--muted); font-size: .95rem; transition: color .2s; }
.nav__links a:hover { color: var(--text); }
.nav__cta { padding: 9px 18px; }
.nav__actions { display: flex; align-items: center; gap: 14px; }

/* 语言切换 */
.lang-toggle {
  display: inline-flex; align-items: center; gap: 2px; padding: 4px;
  border-radius: 999px; border: 1px solid var(--border); background: var(--surface);
  cursor: pointer; font: inherit;
}
.lang-toggle__opt {
  padding: 4px 11px; border-radius: 999px; font-size: .82rem; font-weight: 700;
  color: var(--muted); transition: color .2s, background .2s; line-height: 1;
}
.lang-toggle__opt.is-active { color: #06121a; background: var(--grad); }
.lang-toggle:hover { border-color: rgba(99,102,241,.5); }

/* ===== 按钮 ===== */
.btn {
  display: inline-flex; align-items: center; gap: 10px;
  border-radius: 999px; font-weight: 600; cursor: pointer;
  transition: transform .15s ease, box-shadow .2s ease, background .2s ease;
  border: 1px solid transparent;
}
.btn:active { transform: translateY(1px) scale(.99); }
.btn--ghost { border-color: var(--border); color: var(--text); background: var(--surface); }
.btn--ghost:hover { background: var(--surface-2); }
.btn--primary {
  background: var(--grad); color: #06121a; padding: 14px 26px;
  box-shadow: 0 12px 30px rgba(34, 211, 238, 0.25);
}
.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 18px 40px rgba(99, 102, 241, 0.4); }
.btn--text { color: var(--muted); padding: 14px 6px; }
.btn--text:hover { color: var(--text); }
.btn--smart .btn__icon { display: inline-flex; }
.btn--smart .btn__icon svg { width: 26px; height: 26px; }
.btn__text { display: flex; flex-direction: column; line-height: 1.15; text-align: left; }
.btn__text small { font-weight: 600; font-size: .7rem; opacity: .8; }
.btn__text strong { font-size: 1.02rem; }

/* ===== 英雄区 ===== */
.hero { padding: 64px 0 40px; }
.hero__inner { display: grid; grid-template-columns: 1.1fr .9fr; gap: 48px; align-items: center; }
.eyebrow {
  display: inline-block; font-size: .8rem; letter-spacing: 2px; text-transform: uppercase;
  color: var(--brand-2); font-weight: 700; margin-bottom: 14px;
}
.hero__title { font-size: clamp(2.6rem, 6vw, 4.2rem); line-height: 1.05; font-weight: 800; letter-spacing: -1px; }
.hero__sub { color: var(--muted); font-size: 1.12rem; margin: 20px 0 30px; max-width: 30ch; }
.hero__download { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; }
.hero__stats { display: flex; gap: 36px; margin-top: 44px; list-style: none; }
.hero__stats li { display: flex; flex-direction: column; }
.hero__stats strong { font-size: 1.5rem; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero__stats span { color: var(--muted); font-size: .85rem; }

/* 手机 mockup */
.hero__visual { display: flex; justify-content: center; }
.phone {
  position: relative; width: 280px; height: 560px; border-radius: 42px;
  background: linear-gradient(160deg, #1b2236, #0d1322);
  border: 1px solid var(--border); padding: 14px;
  box-shadow: var(--shadow); animation: float 6s ease-in-out infinite;
}
@keyframes float { 0%,100% { transform: translateY(0); } 50% { transform: translateY(-14px); } }
.phone__notch { position: absolute; top: 14px; left: 50%; transform: translateX(-50%); width: 120px; height: 24px; background: #0d1322; border-radius: 0 0 16px 16px; z-index: 2; }
.phone__screen { height: 100%; border-radius: 30px; background: linear-gradient(180deg, #0f1626, #0b1020); padding: 40px 16px 16px; display: flex; flex-direction: column; gap: 12px; overflow: hidden; }
.chat__bar { display: flex; align-items: center; gap: 8px; font-size: .8rem; color: var(--muted); padding-bottom: 8px; border-bottom: 1px solid var(--border); }
.chat__bar .dot { width: 8px; height: 8px; border-radius: 50%; background: #34d399; }
.bubble { max-width: 80%; padding: 10px 14px; border-radius: 16px; font-size: .85rem; animation: pop .5s ease both; }
.bubble--in { align-self: flex-start; background: var(--surface-2); border-bottom-left-radius: 4px; }
.bubble--out { align-self: flex-end; background: var(--grad); color: #06121a; border-bottom-right-radius: 4px; }
.bubble:nth-child(2) { animation-delay: .2s; }
.bubble:nth-child(3) { animation-delay: .6s; }
.bubble:nth-child(4) { animation-delay: 1s; }
.bubble:nth-child(5) { animation-delay: 1.4s; }
@keyframes pop { from { opacity: 0; transform: translateY(8px) scale(.96); } to { opacity: 1; transform: none; } }
.typing { display: flex; gap: 4px; padding: 14px; }
.typing span { width: 7px; height: 7px; border-radius: 50%; background: #06121a; opacity: .6; animation: blink 1.2s infinite; }
.typing span:nth-child(2){ animation-delay:.2s } .typing span:nth-child(3){ animation-delay:.4s }
@keyframes blink { 0%,60%,100%{ opacity:.3 } 30%{ opacity:1 } }

/* ===== 通用区块 ===== */
.section { padding: 86px 0; }
.section--alt { background: var(--bg-soft); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.section__title { font-size: clamp(1.8rem, 3.5vw, 2.6rem); font-weight: 800; text-align: center; letter-spacing: -.5px; }
.section__sub { text-align: center; color: var(--muted); margin-top: 12px; }

.grid { display: grid; gap: 20px; margin-top: 48px; }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
.grid--4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 28px; transition: transform .2s, border-color .2s, background .2s;
}
.card:hover { transform: translateY(-4px); border-color: rgba(99,102,241,.5); background: var(--surface-2); }
.card__icon { font-size: 2rem; margin-bottom: 14px; }
.card h3 { font-size: 1.15rem; margin-bottom: 8px; }
.card p { color: var(--muted); font-size: .95rem; }

/* ===== 安全区 ===== */
.security__inner { display: grid; grid-template-columns: 1.2fr .8fr; gap: 40px; align-items: center; }
.checklist { list-style: none; margin-top: 24px; display: flex; flex-direction: column; gap: 14px; }
.checklist li { position: relative; padding-left: 34px; color: var(--muted); }
.checklist li::before {
  content: "✓"; position: absolute; left: 0; top: 0; width: 22px; height: 22px;
  border-radius: 50%; background: var(--grad); color: #06121a; font-weight: 800;
  display: grid; place-items: center; font-size: .8rem;
}
.security__badge { display: flex; justify-content: center; }
.shield { font-size: 7rem; filter: drop-shadow(0 20px 40px rgba(99,102,241,.4)); animation: float 5s ease-in-out infinite; }

/* ===== 下载区 ===== */
.platforms { margin-top: 44px; }
.platform {
  display: flex; flex-direction: column; align-items: center; text-align: center;
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 30px 20px; transition: transform .2s, border-color .2s, background .2s, box-shadow .2s;
  position: relative;
}
.platform:hover { transform: translateY(-5px); background: var(--surface-2); border-color: rgba(34,211,238,.5); }
.platform__icon { color: var(--text); margin-bottom: 14px; opacity: .92; }
.platform h3 { font-size: 1.2rem; }
.platform p { color: var(--muted); font-size: .85rem; margin: 6px 0 18px; }
.platform__btn {
  margin-top: auto; padding: 9px 24px; border-radius: 999px;
  border: 1px solid var(--border); background: var(--surface-2); font-weight: 600; font-size: .9rem;
  transition: background .2s, color .2s;
}
.platform:hover .platform__btn { background: var(--grad); color: #06121a; border-color: transparent; }

/* 当前系统推荐高亮 */
.platform.is-recommended {
  border-color: transparent; background: linear-gradient(var(--bg-soft), var(--bg-soft)) padding-box,
    var(--grad) border-box; box-shadow: 0 16px 40px rgba(99,102,241,.25);
}
.platform.is-recommended::after {
  content: attr(data-recommend-label); position: absolute; top: -12px; left: 50%; transform: translateX(-50%);
  background: var(--grad); color: #06121a; font-size: .72rem; font-weight: 700;
  padding: 4px 12px; border-radius: 999px; white-space: nowrap;
}
.platform.is-recommended .platform__btn { background: var(--grad); color: #06121a; border-color: transparent; }

.download__note { text-align: center; color: var(--muted); font-size: .85rem; margin-top: 28px; }
.download__note a { color: var(--brand-2); }

/* ===== 法律页（条款 / 隐私）===== */
.legal { padding: 56px 0 72px; }
.legal__inner { width: min(820px, 92vw); }
.legal .eyebrow { margin-bottom: 10px; }
.legal__title { font-size: clamp(2rem, 4vw, 2.8rem); font-weight: 800; letter-spacing: -.5px; }
.legal__updated { color: var(--muted); font-size: .9rem; margin-top: 8px; }
.legal__intro {
  color: var(--text); margin-top: 24px; padding: 18px 20px;
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
}
.legal h2 { font-size: 1.25rem; margin: 36px 0 12px; }
.legal p { color: var(--muted); margin-bottom: 12px; }
.legal ul { color: var(--muted); margin: 0 0 14px; padding-left: 22px; display: flex; flex-direction: column; gap: 8px; }
.legal li { line-height: 1.6; }
.legal strong { color: var(--text); }
.legal a { color: var(--brand-2); }
.legal a:hover { text-decoration: underline; }
.legal__note {
  margin-top: 40px; padding: 14px 18px; font-size: .88rem;
  border-left: 3px solid var(--brand); background: var(--surface); border-radius: 0 12px 12px 0;
}

/* ===== 页脚 ===== */
.footer { border-top: 1px solid var(--border); padding: 56px 0 30px; background: var(--bg-soft); }
.footer__inner { display: flex; justify-content: space-between; gap: 40px; flex-wrap: wrap; }
.footer__brand p { color: var(--muted); margin-top: 10px; max-width: 22ch; }
.footer__cols { display: flex; gap: 64px; flex-wrap: wrap; }
.footer__cols h4 { font-size: .95rem; margin-bottom: 14px; }
.footer__cols a { display: block; color: var(--muted); font-size: .9rem; margin-bottom: 8px; transition: color .2s; }
.footer__cols a:hover { color: var(--text); }
.footer__bottom { margin-top: 40px; padding-top: 20px; border-top: 1px solid var(--border); color: var(--muted); font-size: .85rem; }

/* ===== 响应式 ===== */
/* 平板 / 中屏（含 iPad 横竖屏）*/
@media (max-width: 900px) {
  .hero { padding: 40px 0 24px; }
  .hero__inner { grid-template-columns: 1fr; gap: 32px; }
  .hero__visual { order: -1; }
  .phone { width: 240px; height: 480px; }
  .grid--3, .grid--4 { grid-template-columns: repeat(2, 1fr); }
  .security__inner { grid-template-columns: 1fr; gap: 28px; }
  .nav__links { display: none; }
  .section { padding: 64px 0; }
}
/* 手机 */
@media (max-width: 600px) {
  .grid--3, .grid--4 { grid-template-columns: 1fr; }
  .section { padding: 52px 0; }
  .footer__inner { flex-direction: column; gap: 28px; }
  .footer__cols { gap: 32px; }
  .hero__download { width: 100%; }
  .hero__download .btn--smart { width: 100%; justify-content: center; }
  .nav__cta { display: none; }
  .shield { font-size: 5rem; }
  .legal__intro { padding: 16px; }
}
/* 小屏手机 */
@media (max-width: 380px) {
  .container { width: 94vw; }
  .phone { width: 210px; height: 420px; }
  .brand__name { font-size: 1rem; }
}
/* 超宽屏：避免内容过度拉伸 */
@media (min-width: 1440px) {
  .container { width: min(1180px, 88vw); }
}