/* ============================================================
   BOTÕES
   Padrões: primary, secondary, tertiary, success, warning,
   danger, outline, icon-only. Estados: hover, focus, active,
   disabled, loading. Tamanhos: sm, md (padrão), lg.
   ============================================================ */

.btn {
    border-radius: var(--radius-md);
    font-weight: var(--font-weight-semibold);
    padding: var(--space-3) var(--space-5);
    font-size: var(--font-size-md);
    line-height: 1.4;
    transition: background var(--transition-fast), border-color var(--transition-fast), color var(--transition-fast), box-shadow var(--transition-fast);
    border: 1px solid transparent;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    white-space: nowrap;
    min-height: 40px;
}

.btn:active {
    transform: translateY(1px);
}

.btn:disabled,
.btn.disabled {
    opacity: 0.55;
    cursor: not-allowed;
    pointer-events: none;
    transform: none;
}

/* ---------- Primário ---------- */
.btn-primary {
    background: var(--primary);
    border-color: var(--primary);
    color: var(--text-on-primary);
}

.btn-primary:hover {
    background: var(--primary-hover);
    border-color: var(--primary-hover);
    color: var(--text-on-primary);
}

.btn-primary:active {
    background: var(--primary-active);
    border-color: var(--primary-active);
}

/* ---------- Secundário ---------- */
.btn-secondary {
    background: var(--secondary);
    border-color: var(--secondary);
    color: #fff;
}

.btn-secondary:hover {
    background: #125d92;
    border-color: #125d92;
    color: #fff;
}

/* ---------- Terciário (texto/discreto) ---------- */
.btn-tertiary {
    background: transparent;
    border-color: transparent;
    color: var(--primary);
}

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

/* ---------- Semânticos ---------- */
.btn-success {
    background: var(--success);
    border-color: var(--success);
    color: #fff;
}
.btn-success:hover { background: #157347; border-color: #157347; }

.btn-warning {
    background: var(--warning);
    border-color: var(--warning);
    color: #fff;
}
.btn-warning:hover { background: #b45f04; border-color: #b45f04; }

.btn-danger {
    background: var(--danger);
    border-color: var(--danger);
    color: #fff;
}
.btn-danger:hover { background: var(--danger-hover); border-color: var(--danger-hover); }

/* ---------- Outline ---------- */
.btn-outline-primary {
    background: var(--surface);
    border-color: var(--primary);
    color: var(--primary);
}
.btn-outline-primary:hover {
    background: var(--primary);
    border-color: var(--primary);
    color: #fff;
}

.btn-outline-secondary {
    background: var(--surface);
    border-color: var(--border);
    color: var(--text-primary);
}
.btn-outline-secondary:hover {
    background: var(--surface-secondary);
    border-color: var(--primary);
    color: var(--primary);
}

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

/* ---------- Somente ícone ---------- */
.btn-icon {
    width: 40px;
    height: 40px;
    padding: 0;
    flex-shrink: 0;
}

.btn-icon.btn-sm {
    width: 32px;
    height: 32px;
}

/* ---------- Tamanhos ---------- */
.btn-sm {
    padding: var(--space-2) var(--space-4);
    font-size: var(--font-size-sm);
    min-height: 32px;
}

.btn-lg {
    padding: var(--space-4) var(--space-6);
    font-size: var(--font-size-lg);
    min-height: 48px;
}

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

.btn.is-loading::after {
    content: '';
    position: absolute;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    border: 2px solid rgba(255, 255, 255, 0.45);
    border-top-color: #fff;
    animation: btn-spin 0.6s linear infinite;
}

.btn-outline-primary.is-loading::after,
.btn-outline-secondary.is-loading::after,
.btn-tertiary.is-loading::after {
    border-color: rgba(15, 76, 129, 0.25);
    border-top-color: var(--primary);
}

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

/* ---------- Grupo de botões que reflui em telas pequenas ---------- */
.page-actions {
    display: flex;
    gap: var(--space-3);
    flex-wrap: wrap;
}

@media (prefers-reduced-motion: reduce) {
    .btn.is-loading::after {
        animation-duration: 1.5s;
    }
}