:root{
  --blue-dark:#4b1f8c; /* updated */
  --blue:#7a3bd1; /* updated */
  --blue-grad-start:#7a3bd1; /* updated */
  --blue-grad-end:#c69bff; /* updated */
  --gold:#e8c4ff; /* updated */
  --card:#ffffff;
  --bg:#f7f2ff; /* updated */
  --text:#0f172a;
  --muted:#475569;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0;background:var(--bg);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","Microsoft JhengHei","PingFang TC",Roboto,Arial,sans-serif;line-height:1.65}
/* Mobile-first nav with hamburger */
.nav{position:sticky;top:0;z-index:1000;background:linear-gradient(90deg,var(--blue-dark),var(--blue));color:#fff;box-shadow:0 4px 14px rgba(0,0,0,.12)}
.nav-inner{display:flex;align-items:center;justify-content:space-between;padding:12px 16px;gap:10px}
.logo{font-weight:800;letter-spacing:.3px}
.lang-toggle{font-weight:700;color:var(--gold);cursor:pointer;margin-left:8px}
.menu-btn{appearance:none;background:transparent;border:0;color:#fff;font-size:22px;line-height:1.2;padding:6px 8px;border-radius:8px}
.menu{display:none;flex-direction:column;padding:8px 12px;background:rgba(255,255,255,.08)}
.menu a{padding:10px 8px;border-radius:10px;color:#fff;text-decoration:none;font-weight:600}
.menu a:active{background:rgba(255,255,255,.18)}
.menu.open{display:flex}
@media(min-width:900px){
  .menu{display:flex!important;flex-direction:row;background:transparent;padding:0 16px;gap:12px}
  .menu a{padding:10px 12px}
  .menu-btn{display:none}
}

header{background:linear-gradient(135deg,var(--blue-grad-start),var(--blue-grad-end));color:#fff;text-align:center;padding:84px 18px 72px;border-bottom-left-radius:18px;border-bottom-right-radius:18px}
header h1{margin:0;font-size:clamp(26px,4.8vw,44px);font-weight:900;padding: 100px 0px}
header p{margin:8px 0 0;font-size:clamp(14px,3.8vw,18px);opacity:.95}

.container{max-width:1480px;margin:0 auto;padding:0 14px}
.section{margin:18px auto 18px;background:var(--card);border-radius:16px;box-shadow:0 8px 28px rgba(16,24,40,.06);padding:18px;opacity:0;transform:translateY(32px);transition:all .8s ease}
.section.visible{opacity:1;transform:translateY(0)}
.section h2{margin:4px 0 10px;text-align:center;color:var(--blue);font-size:clamp(20px,5vw,28px)}
.section h3{margin:14px 0 6px;color:#0b4ea2;font-size:clamp(16px,4.2vw,20px)}
.section p,.section li{font-size:clamp(14px,3.9vw,17px)}
ul{padding-left:18px;margin:8px 0 8px 0}

.badge{display:inline-block;background:#e6f2ff;color:#0b4ea2;border:1px solid #b3dcff;padding:4px 10px;border-radius:999px;font-size:12px;margin:4px 6px 8px 0}

footer{background:var(--blue-dark);color:#fff;text-align:center;padding:18px 12px;margin-top:24px;border-top-left-radius:16px;border-top-right-radius:16px;font-size:13px}
/* Back to top button */
#backToTop{position:fixed;right:14px;bottom:16px;background:var(--blue);color:#fff;border:0;border-radius:999px;padding:10px 14px;font-weight:800;box-shadow:0 10px 24px rgba(0,0,0,.18);display:none}
#backToTop:active{transform:scale(.98)}
/* Smooth anchors */
html{scroll-behavior:smooth}
/* Language helper (only one visible at a time) */
[data-en],[data-zh]{transition:opacity .25s ease}
img{max-width: 50%;margin:0 auto}