body {
    font-family: 'Arial', sans-serif;
    background-color: #f4f7f6;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    padding: 20px;
    box-sizing: border-box;
}

.container {
    background-color: #ffffff;
    padding: 30px 40px;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 400px;
    text-align: center;
}

h1 {
    color: #333;
    margin-bottom: 25px;
    font-size: 1.8em;
}

.input-group {
    margin-bottom: 15px;
    text-align: left;
}

.input-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
    color: #555;
}

.input-group input[type="number"] {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 6px;
    box-sizing: border-box;
    font-size: 1em;
}

#calculate-btn {
    width: 100%;
    padding: 12px;
    background-color: #007bff;
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1.1em;
    font-weight: bold;
    margin-top: 10px;
    transition: background-color 0.3s ease;
}

#calculate-btn:hover {
    background-color: #0056b3;
}

.result-container {
    margin-top: 30px;
    padding: 20px;
    background-color: #e9ecef;
    border-radius: 8px;
    border-left: 5px solid #007bff;
}

.result-container h2 {
    margin-top: 0;
    color: #333;
    font-size: 1.4em;
}

#bmi-output {
    font-size: 2.5em;
    font-weight: bold;
    color: #007bff;
    margin: 10px 0;
}

#bmi-category {
    font-size: 1.1em;
    font-weight: 600;
    color: #555;
}

/* Style for categories */
.underweight {
    color: #ffc107 !important;
    border-color: #ffc107 !important;
}
.normal {
    color: #28a745 !important;
    border-color: #28a745 !important;
}
.overweight {
    color: #fd7e14 !important;
    border-color: #fd7e14 !important;
}
.obese {
    color: #dc3545 !important;
    border-color: #dc3545 !important;
}