:root {
    --primary-color: #4a6fa5;
    --secondary-color: #6b8cae;
    --accent-color: #ff7e5f;
    --light-color: #f8f9fa;
    --dark-color: #343a40;
    --success-color: #28a745;
    --warning-color: #ffc107;
    --danger-color: #dc3545;
    --border-radius: 8px;
    --box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: #f5f7fa;
    color: var(--dark-color);
    line-height: 1.6;
}

.container {
    max-width: 800px;
    margin: 2rem auto;
    padding: 2rem;
    background-color: white;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
}

h1 {
    text-align: center;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    font-weight: 600;
}

.description {
    text-align: center;
    margin-bottom: 2rem;
    color: #666;
}

.calculator-form {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

.form-group {
    margin-bottom: 1.2rem;
}

.form-group.full-width {
    grid-column: span 2;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--dark-color);
}

input, select {
    width: 100%;
    padding: 0.8rem;
    border: 1px solid #ddd;
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: border-color 0.3s;
}

input:focus, select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(74, 111, 165, 0.2);
}

.radio-group {
    display: flex;
    gap: 1rem;
}

.radio-option {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.radio-option input {
    width: auto;
}

.unit-toggle {
    display: flex;
    background-color: #eee;
    border-radius: var(--border-radius);
    padding: 0.3rem;
    margin-bottom: 0.5rem;
}

.unit-toggle button {
    flex: 1;
    padding: 0.5rem;
    border: none;
    background: none;
    cursor: pointer;
    border-radius: calc(var(--border-radius) - 2px);
    font-weight: 500;
    transition: all 0.3s;
}

.unit-toggle button.active {
    background-color: var(--primary-color);
    color: white;
}

.height-inputs, .weight-inputs {
    display: flex;
    gap: 1rem;
}

.height-inputs > div, .weight-inputs > div {
    flex: 1;
}

.imperial-inputs, .metric-inputs {
    display: none;
}

.imperial-inputs.active, .metric-inputs.active {
    display: block;
}

button[type="submit"] {
    grid-column: span 2;
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 1rem;
    border-radius: var(--border-radius);
    font-size: 1.1rem;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 0.3s;
}

button[type="submit"]:hover {
    background-color: var(--secondary-color);
}

.result-container {
    margin-top: 2rem;
    padding: 1.5rem;
    border-radius: var(--border-radius);
    background-color: #f8f9fa;
    display: none;
}

.result-container.active {
    display: block;
    animation: fadeIn 0.5s ease-in-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.result-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.bmi-value {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.bmi-category {
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius);
    font-weight: 500;
    color: white;
}

.category-underweight {
    background-color: var(--warning-color);
}

.category-normal {
    background-color: var(--success-color);
}

.category-overweight {
    background-color: var(--warning-color);
}

.category-obese {
    background-color: var(--danger-color);
}

.result-details {
    margin-top: 1rem;
}

.result-details p {
    margin-bottom: 0.5rem;
}

/* Speedometer Styles */
.speedometer {
    width: 100%;
    max-width: 400px;
    margin: 2rem auto;
    position: relative;
}

.speedometer-body {
    width: 100%;
    height: 200px;
    position: relative;
    overflow: hidden;
}

.speedometer-gauge {
    width: 100%;
    height: 100%;
    position: relative;
    border-top-left-radius: 200px;
    border-top-right-radius: 200px;
    background: conic-gradient(
        #3498db 0deg,
        #2ecc71 72deg,
        #f1c40f 144deg,
        #e67e22 216deg,
        #e74c3c 288deg
    );
    overflow: hidden;
}

.speedometer-center {
    position: absolute;
    width: 60%;
    height: 60%;
    background: white;
    border-radius: 50%;
    top: 40%;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
}

.speedometer-pointer {
    position: absolute;
    width: 4px;
    height: 45%;
    background: var(--dark-color);
    bottom: 50%;
    left: 50%;
    transform-origin: bottom center;
    transform: translateX(-50%) rotate(-90deg);
    transition: transform 0.5s ease;
    z-index: 2;
}

.speedometer-pointer::before {
    content: '';
    position: absolute;
    width: 0;
    height: 0;
    border-left: 10px solid transparent;
    border-right: 10px solid transparent;
    border-bottom: 20px solid var(--dark-color);
    bottom: 100%;
    left: 50%;
    transform: translateX(-50%);
}

.speedometer-labels {
    display: flex;
    justify-content: space-between;
    margin-top: 1rem;
}

.speedometer-label {
    flex: 1;
    text-align: center;
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--dark-color);
    position: relative;
}

.speedometer-label::before {
    content: '';
    position: absolute;
    top: -10px;
    left: 50%;
    width: 2px;
    height: 10px;
    background: var(--dark-color);
    transform: translateX(-50%);
}

.current-bmi {
    font-size: 1.8rem;
    font-weight: bold;
    color: var(--primary-color);
}

.current-category {
    font-size: 1rem;
    color: #666;
    margin-top: 0.5rem;
}

@media (max-width: 768px) {
    .calculator-form {
        grid-template-columns: 1fr;
    }

    .form-group.full-width, button[type="submit"] {
        grid-column: span 1;
    }

    .height-inputs, .weight-inputs {
        flex-direction: column;
        gap: 0;
    }
}