.btn {
  --btn-bg: var(--primary);
  --btn-fg: #fff;
  --btn-border: transparent;
  --btn-hover: var(--primary-dark);
  --btn-shadow: 0 8px 20px rgba(15, 110, 106, 0.16);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  min-height: 44px;
  padding: 0.72rem 1.2rem;
  border: 1px solid var(--btn-border);
  border-radius: 12px;
  background: var(--btn-bg);
  color: var(--btn-fg);
  font-weight: 650;
  letter-spacing: -0.02em;
  line-height: 1;
  white-space: nowrap;
  max-width: 100%;
  box-sizing: border-box;
  box-shadow: none;
  transition:
    background 180ms var(--ease),
    color 180ms var(--ease),
    transform 180ms var(--ease),
    box-shadow 180ms var(--ease),
    border-color 180ms var(--ease),
    opacity 180ms var(--ease),
    filter 180ms var(--ease);
}

.btn:hover {
  background: var(--btn-hover);
  box-shadow: var(--btn-shadow);
  transform: translateY(-1px);
}

.btn:active {
  transform: translateY(0);
  box-shadow: none;
  filter: brightness(0.97);
}

.btn:disabled,
.btn.is-disabled {
  opacity: 0.5;
  pointer-events: none;
  box-shadow: none;
  transform: none;
}

.btn.is-loading {
  pointer-events: none;
  position: relative;
  color: transparent !important;
}

.btn.is-loading::after {
  content: "";
  position: absolute;
  width: 1rem;
  height: 1rem;
  border: 2px solid currentColor;
  border-right-color: transparent;
  border-radius: 50%;
  color: var(--btn-fg);
  animation: spin 0.7s linear infinite;
}

.btn-primary {
  --btn-bg: linear-gradient(165deg, #14807b 0%, var(--primary) 48%, var(--primary-dark) 100%);
  --btn-fg: #fff;
  --btn-hover: linear-gradient(165deg, #17918b 0%, #0f6e6a 45%, #0a4f4c 100%);
  --btn-shadow: 0 10px 26px rgba(15, 110, 106, 0.22);
  background: var(--btn-bg);
  border-color: transparent;
}

.btn-primary:hover {
  background: var(--btn-hover);
}

.btn-secondary {
  --btn-bg: var(--secondary);
  --btn-fg: #fff;
  --btn-hover: #0d1016;
  --btn-shadow: 0 10px 24px rgba(23, 26, 33, 0.22);
}

.btn-outline {
  --btn-bg: rgba(255, 255, 255, 0.55);
  --btn-fg: var(--text-primary);
  --btn-border: #d8d4c8;
  --btn-hover: #fff;
  --btn-shadow: 0 8px 18px rgba(20, 23, 28, 0.08);
  backdrop-filter: blur(6px);
}

.btn-outline:hover {
  background: var(--btn-hover);
  border-color: #c4bfb1;
}

.btn-ghost {
  --btn-bg: transparent;
  --btn-fg: var(--text-primary);
  --btn-hover: var(--surface-soft);
  --btn-shadow: none;
}

.btn-ghost:hover {
  box-shadow: none;
}

.btn-danger {
  --btn-bg: var(--danger);
  --btn-fg: #fff;
  --btn-hover: #9f2d28;
  --btn-shadow: 0 10px 22px rgba(194, 65, 59, 0.2);
}

.btn-sm {
  min-height: 36px;
  padding: 0.45rem 0.9rem;
  font-size: var(--text-small);
  border-radius: 10px;
}

.btn-lg {
  min-height: 52px;
  padding: 0.95rem 1.5rem;
  font-size: 1.05rem;
  border-radius: 14px;
}

.btn-icon {
  width: 44px;
  height: 44px;
  padding: 0;
  border-radius: 12px;
  background: transparent;
  color: var(--text-primary);
  --btn-shadow: none;
}

.btn-icon:hover {
  background: var(--surface-soft);
  box-shadow: none;
  transform: none;
}

.btn-block {
  width: 100%;
}

.btn-accent {
  --btn-bg: linear-gradient(165deg, #d4b03a 0%, var(--accent) 50%, #a8841a 100%);
  --btn-fg: #171a21;
  --btn-hover: linear-gradient(165deg, #dfbc4a 0%, #c9a227 50%, #9a7916 100%);
  --btn-shadow: 0 10px 24px rgba(201, 162, 39, 0.28);
  background: var(--btn-bg);
  font-weight: 700;
}

.btn-accent:hover {
  background: var(--btn-hover);
}