/* Boc tham trung thuong */
:root { --pri: #b91c1c; --gold: #f59e0b; --ink: #111827; --ink2: #4b5563; --line: #e5e7eb; --bg: #fff8f0; }
* { box-sizing: border-box; }
[hidden] { display: none !important; }
body { margin: 0; font-family: system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif; color: var(--ink); background: var(--bg); line-height: 1.5; }
a { color: var(--pri); }
.bt-top { display: flex; justify-content: space-between; align-items: center; gap: 10px; padding: 10px 16px; background: #fff; border-bottom: 1px solid var(--line); font-size: 14px; }
.bt-logo { display: flex; align-items: center; gap: 8px; font-weight: 700; color: var(--ink); text-decoration: none; font-size: 16px; }
.bt-main { max-width: 900px; margin: 0 auto; padding: 16px; }
.bt-hero h1 { font-size: clamp(26px, 5vw, 38px); margin: 8px 0 6px; line-height: 1.2; } .bt-hero h1 span { color: var(--pri); }
.bt-hero p { color: var(--ink2); margin: 0 0 14px; }
.bt-setup { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; background: #fff; border: 1px solid var(--line); border-radius: 16px; padding: 16px; }
.bt-setup label { display: block; font-weight: 600; } .bt-setup small { font-weight: 400; color: var(--ink2); }
.bt-setup textarea { width: 100%; margin-top: 4px; padding: 10px; border: 1px solid #d1d5db; border-radius: 10px; font: inherit; font-size: 15px; }
.bt-row { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; grid-column: 1 / -1; margin-top: 6px; }
.bt-btn { background: var(--pri); color: #fff; border: 0; border-radius: 999px; padding: 10px 20px; font: inherit; font-weight: 700; cursor: pointer; }
.bt-btn.alt { background: #fff; color: var(--pri); border: 2px solid var(--pri); padding: 8px 18px; }
.bt-btn.big { font-size: 22px; padding: 14px 36px; } .bt-btn:disabled { opacity: .5; cursor: default; }
.bt-stage { margin: 18px 0; background: linear-gradient(135deg, #7f1d1d, #b91c1c 55%, #d97706); color: #fff; border-radius: 20px; padding: 26px 16px; text-align: center; }
.bt-cur { font-size: clamp(20px, 3.5vw, 30px); font-weight: 700; color: #fde68a; }
.bt-roll { font-size: clamp(32px, 7vw, 64px); font-weight: 800; min-height: 1.4em; margin: 18px 0; word-break: break-word; }
.bt-roll.rolling { opacity: .85; } .bt-roll.won { animation: bt-pop .6s ease; color: #fff7d6; text-shadow: 0 0 24px rgba(253, 230, 138, .9); }
@keyframes bt-pop { 0% { transform: scale(.8); } 60% { transform: scale(1.12); } 100% { transform: scale(1); } }
.bt-ctrl { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; } .bt-stage .bt-btn { background: #fde68a; color: #7f1d1d; } .bt-stage .bt-btn.alt { background: transparent; color: #fff; border-color: #fde68a; }
.bt-left { color: #fde68a; margin: 10px 0 0; }
.bt-res { background: #fff; border: 1px solid var(--line); border-radius: 16px; padding: 16px; }
.bt-res h2 { margin: 0 0 8px; } .bt-g h3 { margin: 12px 0 4px; color: var(--pri); } .bt-g h3 small { color: var(--ink2); font-weight: 400; }
.bt-g ol { margin: 0; padding-left: 22px; columns: 2; } .bt-x { border: 0; background: none; color: #9ca3af; cursor: pointer; }
.bt-note { color: var(--ink2); }
.bt-seo { margin-top: 20px; } .bt-seo h2 { font-size: 21px; margin: 20px 0 8px; }
.bt-seo details { background: #fff; border: 1px solid var(--line); border-radius: 10px; padding: 10px 14px; margin-bottom: 8px; } .bt-seo summary { font-weight: 600; cursor: pointer; }
body.stage { background: #450a0a; } body.stage .no-stage { display: none !important; }
body.stage .bt-main { max-width: none; min-height: 100vh; display: flex; flex-direction: column; justify-content: center; }
body.stage .bt-stage { margin: 0 0 16px; padding: 6vh 4vw; } body.stage .bt-roll { font-size: clamp(48px, 9vw, 120px); }
body.stage .bt-res { background: rgba(255,255,255,.08); border: 0; color: #fff; } body.stage .bt-g h3 { color: #fde68a; }
@media (max-width: 700px) { .bt-setup { grid-template-columns: 1fr; } .bt-g ol { columns: 1; } }