.btn-calculate{display:flex;align-items:center;justify-content:center;width:100%;min-height:48px;padding:clamp(0.75rem,1.5vw,0.875rem) clamp(1rem,2vw,1.25rem);background:var(--brand-primary);border:none;border-radius:10px;color:#fff;font-size:clamp(0.8125rem,1.2vw + 0.1rem,0.875rem);font-weight:700;box-shadow:var(--shadow-sm);cursor:pointer;transition:background-color 0.2s ease,box-shadow 0.2s ease,opacity 0.2s ease}.btn-calculate:hover:not(:disabled){background:var(--brand-primary-dark);box-shadow:var(--shadow-md)}.btn-calculate:active:not(:disabled){opacity:0.9}.btn-calculate:disabled{opacity:0.4;cursor:not-allowed;background:var(--bg-tertiary);color:var(--text-muted)}.btn-calculate .btn-loading{display:flex;align-items:center;gap:0.5rem}.btn-calculate .spin{animation:spin 1s linear infinite}