/* ===== 通用 ===== */
* { box-sizing:border-box; margin:0; padding:0; }
body {
  font-family:-apple-system,BlinkMacSystemFont,"Helvetica Neue",Helvetica,Arial,sans-serif;
  color:#1d1d1f;
  background:#fff;
  overflow-x:hidden; /* 防止左右多余滚动 */
}
a { text-decoration:none; color:inherit; }

/* ===== header ===== */
header {
  height:64px;
  border-bottom:1px solid #eee;
  display:flex;
  justify-content:center;
  align-items:center;
  position:sticky;
  top:0;
  background:#fff;
  z-index:20;
}
.nav {
  width:100%;
  max-width:1200px;
  padding:0 24px;
  display:flex;
  align-items:center;
  justify-content:space-between;
}
.nav-left img.nav-logo {
  height:28px;
  transition:transform 0.3s ease;
}
.nav-left img.nav-logo:hover {
  transform:scale(1.05);
}
.nav-right {
  display:flex;
  align-items:center;
  gap:24px;
  font-size:14px;
}
.lang-switch { cursor:pointer; opacity:0.6; }
.lang-switch:hover { opacity:1; }

/* ===== 下拉菜单 ===== */
.nav-item { position:relative; cursor:pointer; user-select:none; }
.nav-item span {
  display:inline-block;
  padding:8px;
  transition: background-color 0.25s;
}
.nav-item span:hover { background-color: rgba(0,0,0,0.05); border-radius:6px; }

.nav-item .dropdown-content {
  position:absolute;
  top:100%;
  left:0;
  background:#fff;
  min-width:160px;
  border-radius:8px;
  box-shadow:0 6px 16px rgba(0,0,0,0.08);
  max-height:0;
  opacity:0;
  overflow:hidden;
  transition:max-height 0.5s ease, opacity 0.5s ease;
  z-index:15;
}
.nav-item.open .dropdown-content {
  max-height:500px;
  opacity:1;
}
.nav-item .dropdown-content a {
  display:block;
  padding:10px 16px;
  color:#333;
  transition: background-color 0.25s;
}
.nav-item .dropdown-content a:hover {
  background-color:#f2f2f2;
  border-radius:6px;
}

/* ===== hero ===== */
.hero {
  text-align:center;
  padding:60px 20px;
  overflow:hidden;
}
.hero-logo {
  width:min(160px,40vw);
  margin-bottom:28px;
  transform:scale(0);
  animation:breatheFade 1s ease forwards;
}
@keyframes breatheFade {
  0%{transform:scale(0); opacity:0;}
  60%{transform:scale(1.05); opacity:1;}
  100%{transform:scale(1); opacity:1;}
}

.title-cn, .status, .hero-buttons {
  opacity:0;
  transform:translateY(20px);
  animation:fadeUp 0.8s cubic-bezier(.4,0,.2,1) forwards;
}
.title-cn { animation-delay:0.5s; font-size:clamp(22px,5vw,32px); font-weight:600; margin-bottom:6px; }
.status { animation-delay:0.7s; font-size:15px; color:#6e6e73; margin-bottom:24px; }

.hero-buttons {
  display:flex;
  justify-content:center;
  gap:16px;
  animation-delay:0.9s;
}
.hero-buttons .btn {
  padding:10px 24px;
  border-radius:8px;
  font-weight:600;
  cursor:pointer;
  transition:all 0.3s ease;
}
.hero-buttons .btn:hover { opacity:0.85; transform:translateY(-2px); }
.hero-buttons .btn.thank-you { background:#1d1d1f; color:#fff; }
.hero-buttons .btn.roadmap { background:#ff5e5e; color:#fff; }

/* 动画关键帧 */
@keyframes fadeUp {
  from {opacity:0; transform:translateY(20px);}
  to {opacity:1; transform:translateY(0);}
}

/* ===== 响应式 ===== */
@media (max-width:480px){
  .hero-buttons { flex-direction:row; gap:12px; flex-wrap:wrap; justify-content:center; }
  .hero-logo { width:min(120px,50vw); }
  .nav-right { gap:12px; font-size:13px; }
}