/* ===============================
   BUTTON – RED BACKGROUND + SHINE
================================ */
.btn-group {
  display: flex;
  gap: 14px;
  justify-content: center;
  align-items: center;
}

/* ===== Base Button ===== */
.btn {
  padding: 11px 30px;
  font-size: 15px;
  font-weight: 800;
  letter-spacing: 0.8px;
  text-decoration: none;
  text-transform: uppercase;
  color: #111;
  border-radius: 14px;
  position: relative;
  overflow: hidden;
  isolation: isolate;

  background: linear-gradient(
    90deg,
    #fff6c8,
    #ffd700,
    #ffb700,
    #ffd700,
    #fff6c8
  );
  background-size: 400% 100%;
  animation: goldMove 3s linear infinite;

  box-shadow:
    0 0 16px rgba(255, 220, 120, 0.9),
    0 0 36px rgba(255, 200, 60, 1),
    0 0 70px rgba(255, 235, 160, 1);

  border: 1px solid rgba(255, 240, 200, 1);
  transition: all 0.18s ease;
}

/* ===== ÁNH SÁNG QUÉT ===== */
.btn::after {
  content: "";
  position: absolute;
  top: -30%;
  left: -120%;
  width: 60%;
  height: 160%;
  background: linear-gradient(
    120deg,
    transparent,
    rgba(255, 255, 255, 0.85),
    transparent
  );
  transform: skewX(-20deg);
  animation: shineSweep 2.4s ease-in-out infinite;
}

/* ===== Hover ===== */
.btn:hover {
  transform: translateY(-2px) scale(1.06);
  box-shadow:
    0 0 24px rgba(255, 240, 180, 1),
    0 0 55px rgba(255, 215, 120, 1),
    0 0 100px rgba(255, 255, 210, 1);
}

/* ======================
   REGISTER – dịu hơn
====================== */
.btn-register {
  filter: brightness(0.95);
}

/* ======================
   LOGIN – nổi hơn
====================== */
.btn-login {
  animation:
    goldMove 2.2s linear infinite,
    pulseLight 1.4s ease-in-out infinite;
}

/* ===== Halo sáng tách nền đỏ ===== */
.btn-login::before {
  content: "";
  position: absolute;
  inset: -8px;
  border-radius: inherit;
  background: radial-gradient(
    circle,
    rgba(255, 245, 200, 0.75),
    rgba(255, 220, 120, 0.35),
    transparent 72%
  );
  filter: blur(14px);
  z-index: -1;
}

/* ===== Animations ===== */
@keyframes goldMove {
  0%   { background-position: 0% 50%; }
  100% { background-position: 100% 50%; }
}

@keyframes shineSweep {
  0%   { left: -120%; }
  60%  { left: 140%; }
  100% { left: 140%; }
}

@keyframes pulseLight {
  0%,100% {
    box-shadow:
      0 0 20px rgba(255, 235, 160, 1),
      0 0 45px rgba(255, 215, 120, 1),
      0 0 80px rgba(255, 255, 210, 1);
  }
  50% {
    box-shadow:
      0 0 32px rgba(255, 255, 210, 1),
      0 0 70px rgba(255, 235, 160, 1),
      0 0 120px rgba(255, 255, 240, 1);
  }
}