/* Buttons. Every page previously hand-rolled its own button hover/active/
   disabled states. One system here; pages opt into a color variant via
   modifier class instead of redefining the base behavior. */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  border: none;
  border-radius: var(--radius-sm);
  padding: 9px 16px;
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.04em;
  cursor: pointer;
  white-space: nowrap;
  /* Only opacity + transform — both are compositor-only (GPU layer),
     zero paint cost. Background/color transitions were causing paint
     on every hover across the whole button surface. */
  transition: opacity var(--transition-fast), transform 0.1s;
  will-change: opacity, transform;
}

.btn:hover { opacity: 0.88; }
.btn:active { transform: scale(0.97); }
.btn:disabled { opacity: 0.4; cursor: not-allowed; transform: none; will-change: auto; }

.btn-block { width: 100%; }

.btn-primary-green { background: var(--accent-green); color: #07090f; }
.btn-primary-yellow { background: var(--accent-yellow); color: #07090f; }

.btn-danger {
  background: rgba(255,77,109,0.15);
  color: var(--danger);
  border: 1px solid rgba(255,77,109,0.3);
  padding: 6px 12px;
  font-size: 12px;
}
.btn-danger:hover { background: rgba(255,77,109,0.25); opacity: 1; }

.btn-ghost {
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--border);
}
.btn-ghost:hover { color: var(--text); border-color: var(--text); opacity: 1; }

.btn-secondary {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--muted);
  border-radius: var(--radius-sm);
  padding: 9px 16px;
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
  transition: opacity var(--transition-fast), transform 0.1s;
  will-change: opacity, transform;
}
.btn-secondary:hover { opacity: 0.75; }

.btn-accent-soft {
  background: rgba(0,229,160,0.1);
  color: var(--accent-green);
  border: 1px solid rgba(0,229,160,0.25);
  padding: 8px 14px;
  font-size: 12px;
}
.btn-accent-soft:hover { background: rgba(0,229,160,0.18); opacity: 1; }

.btn-yellow-soft {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  width: 100%;
  background: rgba(232,197,71,0.1);
  color: var(--accent-yellow);
  border: 1px solid rgba(232,197,71,0.3);
  border-radius: var(--radius-md);
  padding: 11px 16px;
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
  letter-spacing: 0.04em;
  justify-content: center;
  transition: opacity var(--transition-fast), transform 0.1s;
  will-change: opacity, transform;
}
.btn-yellow-soft:hover { opacity: 0.82; }

/* Spinner — will-change promotes to its own compositor layer so the
   rotation doesn't cause repaints on surrounding content. */
.spinner {
  display: inline-block;
  width: 14px;
  height: 14px;
  border: 2px solid var(--border);
  border-top-color: var(--accent-green);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
  vertical-align: middle;
  margin-right: var(--space-2);
  will-change: transform;
}

.spinner-lg {
  width: 18px;
  height: 18px;
  border-top-color: var(--accent-yellow);
}

@keyframes spin { to { transform: rotate(360deg); } }