.btn{display:inline-flex;align-items:center;justify-content:center;gap:var(--spacing-2);font-family:var(--font-family-sans);font-weight:500;border-radius:var(--radius-md);cursor:pointer;transition:all var(--transition-normal);border:2px solid transparent;text-decoration:none;white-space:nowrap}.btn:disabled{opacity:.5;cursor:not-allowed}.btn:focus-visible{outline:2px solid var(--color-brand-primary);outline-offset:2px;box-shadow:var(--shadow-glow)}.btn-primary{background:var(--color-brand-primary);color:#fff;border-color:var(--color-brand-primary)}.btn-primary:hover:not(:disabled){background:var(--color-brand-primary-hover);border-color:var(--color-brand-primary-hover);box-shadow:var(--shadow-glow)}.btn-primary:active:not(:disabled){transform:scale(.98)}.btn-secondary{background:var(--color-bg-tertiary);color:var(--color-text-primary);border-color:var(--color-border-primary)}.btn-secondary:hover:not(:disabled){background:var(--color-bg-hover);border-color:var(--color-brand-primary)}.btn-outline{background:transparent;color:var(--color-brand-primary);border-color:var(--color-brand-primary)}.btn-outline:hover:not(:disabled){background:var(--color-brand-primary);color:#fff;box-shadow:var(--shadow-glow)}.btn-ghost{background:transparent;color:var(--color-text-primary);border-color:transparent}.btn-ghost:hover:not(:disabled){background:var(--color-bg-hover);border-color:var(--color-border-secondary)}.btn-danger{background:var(--color-error);color:#fff;border-color:var(--color-error)}.btn-danger:hover:not(:disabled){background:#d32f2f;border-color:#d32f2f;box-shadow:0 0 20px #ef53504d}.btn-sm{padding:var(--spacing-1) var(--spacing-3);font-size:var(--font-size-sm);min-height:32px}.btn-md{padding:var(--spacing-2) var(--spacing-4);font-size:var(--font-size-base);min-height:40px}.btn-lg{padding:var(--spacing-3) var(--spacing-6);font-size:var(--font-size-lg);min-height:48px}.btn-full{width:100%}.btn-loading{position:relative;color:transparent}.btn-loading .btn-text{opacity:0}.btn-icon{display:inline-flex;align-items:center;justify-content:center;flex-shrink:0}.btn-icon svg{width:1.25em;height:1.25em}.btn-spinner{position:absolute;display:inline-flex;align-items:center;justify-content:center;color:inherit}.btn-spinner svg{width:1.25em;height:1.25em;animation:spin 1s linear infinite}@keyframes spin{0%{transform:rotate(0)}to{transform:rotate(360deg)}}