.header-button .button.secondary {
  position: relative;
  overflow: hidden;
  background: linear-gradient(
    135deg,
    #c9a96e 0%,
    #e8d5b0 45%,
    #c9a96e 55%,
    #a07840 100%
  ) !important;
  background-size: 200% 100% !important;
  color: #2c1a0e !important;
  padding: 13px 28px !important;     /* mới thêm - quyết định chính độ "to" của nút */
  font-size: 13px !important;        /* tăng từ 12px */
  font-weight: 600 !important;
  letter-spacing: 0.08em !important; /* giảm nhẹ từ 0.1em vì chữ to hơn, để đỡ thưa */
  line-height: normal !important;    /* mới thêm - tránh chữ bị lệch tâm khi padding đổi */
  text-transform: uppercase !important;
  border: none !important;
  border-radius: 2px !important;
  box-shadow:
    0 2px 12px rgba(201,169,110,0.35),
    inset 0 1px 0 rgba(255,255,255,0.3) !important;
  transition: background-position 0.5s ease, transform 0.2s !important;
}
.header-button .button.secondary::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 60%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255,255,255,0.35),
    transparent
  );
  animation: ara-shimmer 2.8s ease-in-out infinite;
}

.header-button .button.secondary:hover {
  background-position: 100% 0 !important;
  transform: translateY(-1px) !important;
  box-shadow:
    0 4px 20px rgba(201,169,110,0.5),
    inset 0 1px 0 rgba(255,255,255,0.3) !important;
}

@keyframes ara-shimmer {
  0%        { left: -100%; }
  60%, 100% { left: 160%; }
}