:root{
  --nen:#1a0a15; --nen2:#2a0f22; --the:#2f1428; --vien:rgba(255,190,215,.18);
  --chu:#fff4f8; --phu:#e7bfd0; --hong:#f48fb5; --hong2:#ff5f99; --vang:#f3cf9a;
}
*{box-sizing:border-box;margin:0;padding:0}
html,body{background:var(--nen);color:var(--chu);font-family:'Be Vietnam Pro',system-ui,sans-serif;-webkit-text-size-adjust:100%}
body{min-height:100vh;background:
  radial-gradient(1200px 600px at 50% -200px,rgba(244,143,181,.28),transparent 70%),
  radial-gradient(800px 500px at 100% 100%,rgba(243,207,154,.10),transparent 70%),var(--nen);background-attachment:fixed}
a{color:inherit}
.dau{text-align:center;padding:22px 16px 6px}
.dau .nho{letter-spacing:.32em;font-size:12px;color:var(--vang);font-weight:600}
.dau h1{font-family:'Great Vibes',cursive;font-weight:400;font-size:clamp(44px,11vw,76px);line-height:1.05;
  background:linear-gradient(180deg,#fff 0%,#ffd3e3 45%,#f48fb5 100%);-webkit-background-clip:text;background-clip:text;color:transparent;
  filter:drop-shadow(0 4px 18px rgba(255,95,153,.35));padding:4px 10px}
.dau .ngay{color:var(--phu);font-size:14px;margin-top:2px}
.bang-khung{max-width:760px;margin:6px auto 0;padding:0 16px}
.bang-khung img{width:100%;display:block;margin-top:-4%;filter:drop-shadow(0 6px 22px rgba(255,95,153,.25))}
.nut{appearance:none;border:0;cursor:pointer;font:inherit;font-weight:700;border-radius:999px;padding:12px 20px;
  background:linear-gradient(135deg,#ff7aa8,#e8467f);color:#fff;box-shadow:0 6px 20px rgba(232,70,127,.35);
  display:inline-flex;align-items:center;gap:8px;justify-content:center;text-decoration:none}
.nut:active{transform:scale(.97)}
.nut.phu{background:rgba(255,255,255,.08);box-shadow:none;border:1px solid var(--vien)}
.nut:disabled{opacity:.5;cursor:default}
.an{display:none!important}