body{margin:0;background:#0f172a;color:#fff;font-family:Arial,sans-serif;overflow-x:hidden}#particles{position:fixed;inset:0;z-index:0}.particle{position:absolute;width:3px;height:3px;background:#fff;border-radius:50%;opacity:.3;animation:float 15s linear infinite}.main-container{position:relative;z-index:2;min-height:100vh;display:flex;align-items:center;justify-content:center}.hero{max-width:800px}.hero h1{font-size:60px;font-weight:700}.countdown{font-size:40px;font-weight:bold;margin:20px 0}.subscribe{display:flex;gap:10px}.floating-contact{position:fixed;bottom:20%;left:50%;transform:translateX(-50%);display:flex;gap:15px;z-index:9999}.floating-contact a{display:flex;align-items:center;gap:10px;padding:14px 24px;border-radius:50px;color:#fff;text-decoration:none;font-weight:700;box-shadow:0 10px 30px rgba(0,0,0,.4);animation:pulse 2s infinite}.zalo-btn{background:#0068ff}.zalo-btn img{width:28px;height:28px}.messenger-btn{background:#0084ff}@keyframes pulse{0%{box-shadow:0 0 0 0 rgba(255,255,255,.4)}70%{box-shadow:0 0 0 20px rgba(255,255,255,0)}100%{box-shadow:0 0 0 0 rgba(255,255,255,0)}}@keyframes float{from{transform:translateY(100vh)}to{transform:translateY(-100px)}}@media(max-width:768px){.hero h1{font-size:36px}.subscribe{flex-direction:column}.floating-contact{width:95%;bottom:15px}.floating-contact a{flex:1;justify-content:center;padding:14px 10px}}