/* General Reset & Body Styling */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Poppins', sans-serif;
    background-color: #f4f7f6;
    color: #333;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 1rem;
}

/* Card Layout */
.card {
    display: flex;
    flex-direction: column;
    max-width: 850px;
    width: 100%;
    background-color: #ffffff;
    border-radius: 20px;
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.12);
    overflow: hidden;
}

/* Wrappers */
.calculator-wrapper,
.result-wrapper {
    padding: 2.5rem;
    flex: 1;
}

.calculator-wrapper {
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.result-wrapper {
    background-color: #3B5998; /* A deep, modern blue */
    color: white;
    text-align: center;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

/* Typography */
h2 {
    font-weight: 600;
    font-size: 1.8rem;
    margin-bottom: 0.5rem;
}

.subtitle {
    color: #777;
    margin-bottom: 2.5rem;
    font-size: 1rem;
}

/* Form Elements */
input {
    width: 100%;
    padding: 14px 18px;
    margin-bottom: 1.2rem;
    border: 1px solid #e0e0e0;
    border-radius: 10px;
    font-family: 'Poppins', sans-serif;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

input:focus {
    outline: none;
    border-color: #3B5998;
}

button {
    width: 100%;
    padding: 14px 18px;
    border: none;
    border-radius: 10px;
    background-color: #3B5998;
    color: white;
    font-family: 'Poppins', sans-serif;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.2s ease;
}

button:hover {
    background-color: #324a7e;
    transform: translateY(-2px);
}

button:disabled {
    background-color: #a9a9a9;
    cursor: not-allowed;
    transform: translateY(0);
}

/* Result Display */
.bmi-gauge {
    position: relative;
    height: 12px;
    background: linear-gradient(to right, #f1c40f, #2ecc71, #e74c3c);
    border-radius: 6px;
    margin: 2rem 0;
}

.bmi-pointer {
    position: absolute;
    top: -6px;
    left: 0;
    width: 24px;
    height: 24px;
    background-color: white;
    border-radius: 50%;
    border: 4px solid #3B5998;
    transform: translateX(-50%);
    transition: left 0.5s ease-out;
}

#result-text {
    font-size: 1.7rem;
    font-weight: 600;
}

#result-category {
    font-size: 1.2rem;
    font-weight: 300;
    min-height: 30px;
    margin-top: 0.5rem;
}

/* Responsive Design */
@media (min-width: 800px) {
    .card {
        flex-direction: row;
    }
}