body {
    background-color: #f3f4f6;
    font-family: "Segoe UI", Arial, sans-serif;
}
.calculator-container {
    margin-top: 50px;
    padding: 30px;
    background-color: #ffffff;
    border-radius: 8px;
    box-shadow: 0 2px 30px rgba(0, 0, 0, 0.18);
    transition: all 0.3s ease;
}
.calculator-container:hover {
    box-shadow: 0 4px 40px rgba(0, 0, 0, 0.25);
}
.result-box {
    margin-top: 20px;
    padding: 15px;
    background-color: #e9ecef;
    border-radius: 4px;
    display: none;
}
.result-box.fade-in {
    animation: fadeIn 0.5s forwards;
}
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}
.btn-primary:hover {
    background-color: #0056b3;
    border-color: #004999;
}
/* Spinner overlay */
.spinner-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.7);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    display: none;
}
/* Inline error messages */
.error-msg {
    color: red;
    font-size: 0.9em;
    display: none;
}

/* Estilos para o switch customizado */
.switch {
    position: relative;
    display: inline-block;
    width: 50px;
    height: 24px;
    margin-left: 10px;
    vertical-align: middle;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0; left: 0; right: 0; bottom: 0;
    background-color: #ccc;
    transition: .4s;
    border-radius: 24px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 18px;
    width: 18px;
    left: 3px;
    bottom: 3px;
    background-color: white;
    transition: .4s;
    border-radius: 50%;
}

input:checked + .slider {
    background-color: #2196F3;
}

input:focus + .slider {
    box-shadow: 0 0 1px #2196F3;
}

input:checked + .slider:before {
    transform: translateX(26px);
}

/* 1) Estilos base da calculadora */
.calculator-container { … }

/* 2) Labels específicos da calculadora */
.calculator-container .form-group > label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 1rem;
    font-weight: 600;
    color: #002a54;
    line-height: 1.4;
}

/* 3) Caso use classe dedicada */
.calculator-label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 1rem;
    font-weight: 700;
    color: #4abe7b;
    text-transform: uppercase;
    letter-spacing: 0.02em;
}