/* ==========================================================================
   Risos Shared — Button Components
   From: web/static/css/style.css lines 552-665 (section 6. BUTTONS)
   Extracted: 28 Mei 2026

   Variants:
     .btn              base
     .btn-primary      gradient navy → cyan
     .btn-secondary    surface w/ border
     .btn-ghost        transparent w/ border (alias: .btn-outline)
     .btn-danger       red gradient
     .btn-success      green gradient
     .btn-crypto       orange gradient
     .btn-sm           small size
     .btn-lg           large size
     .btn.loading      spinner overlay

   Depends: tokens.css (for --radius-*, --color-*, --bg-surface, --border-*)
   ========================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border: none;
  border-radius: var(--radius-md, 12px);
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  transition: all 200ms cubic-bezier(0.4,0,0.2,1);
  position: relative;
  overflow: hidden;
  white-space: nowrap;
  font-family: inherit;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none !important;
  box-shadow: none !important;
}

.btn-primary {
  background: linear-gradient(135deg, var(--c-brand, #1e40af), var(--c-primary-deep, #2563eb));
  color: #fff;
  box-shadow: 0 4px 20px rgba(30,64,175,0.30);
}
.btn-primary:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 6px 30px rgba(30,64,175,0.45);
  color: #fff;
}

.btn-secondary {
  background: var(--bg-surface, var(--bg-elev, #ffffff));
  color: var(--text-secondary, var(--txt-muted, #475569));
  border: 1px solid var(--border-default, var(--line, #e2e8f0));
}
.btn-secondary:hover:not(:disabled) {
  background: var(--bg-surface-hover, color-mix(in oklab, var(--txt, #0f172a) 4%, transparent));
  border-color: var(--border-strong, var(--line-2, #cbd5e1));
  color: var(--text-primary, var(--txt, #0f172a));
}

.btn-ghost,
.btn-outline {
  background: transparent;
  color: var(--text-secondary, var(--txt-muted, #475569));
  border: 1px solid var(--border-default, var(--line, #e2e8f0));
}
.btn-ghost:hover:not(:disabled),
.btn-outline:hover:not(:disabled) {
  border-color: var(--c-brand, #1e40af);
  color: var(--text-primary, var(--txt, #0f172a));
  background: rgba(30,64,175,0.06);
}

.btn-danger {
  background: linear-gradient(135deg, var(--c-danger, #ef4444), #dc2626);
  color: #fff;
  box-shadow: 0 4px 20px rgba(239,68,68,0.30);
}
.btn-danger:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 6px 30px rgba(239,68,68,0.45);
  color: #fff;
}

.btn-success {
  background: linear-gradient(135deg, #22c55e, #16a34a);
  color: #fff;
  box-shadow: 0 4px 20px rgba(34,197,94,0.30);
}
.btn-success:hover:not(:disabled) {
  transform: translateY(-2px);
  color: #fff;
}

.btn-crypto {
  background: linear-gradient(135deg, #f59e0b, #f97316);
  color: #fff;
  box-shadow: 0 4px 20px rgba(245,158,11,0.30);
}
.btn-crypto:hover:not(:disabled) {
  transform: translateY(-2px);
  color: #fff;
}

.btn-sm {
  padding: 6px 14px;
  font-size: 13px;
  border-radius: var(--radius-sm, 8px);
}

.btn-lg {
  padding: 16px 36px;
  font-size: 16px;
  border-radius: var(--radius-lg, 18px);
}

/* Loading spinner inside button */
.btn.loading::before {
  content: '';
  display: inline-block;
  width: 14px;
  height: 14px;
  border: 2px solid rgba(255,255,255,0.3);
  border-top-color: #fff;
  border-radius: 50%;
  animation: btn-spin 0.6s linear infinite;
  margin-right: 4px;
}
@keyframes btn-spin {
  to { transform: rotate(360deg); }
}