:root {
    /* BMI Category Colors */
    --color-underweight: #1d4ed8; 
    --color-normal: #065F46; 
    --color-overweight: #b45309;
    --color-obese-1: #dc2626;
    --color-obese-2: #b91c1c; 
    --color-obese-3: #7f1d1d;
    --color-text-primary: #1a202c;
    --color-text-secondary: #4a5568;
    --color-text-light: #718096;
}

/* BMI-Specific Styles */
.info-card {
    margin-top: 1.5rem;
}

.info-card h2, .info-card h3 {
    text-align: left;
}

.info-card p, .info-card ul {
    text-align: left;
    font-size: 0.875rem;
    margin-bottom: 1rem;
}

.info-card ul {
    list-style-type: none;
    padding-left: 0;
}

.info-card li {
    margin-bottom: 0.75rem;
    display: flex;
    align-items: center;
    font-size: 0.9rem;
}

.info-card li::before {
    content: '';
    display: inline-block;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    margin-right: 0.75rem;
    flex-shrink: 0;
}

.info-card li.bmi-underweight::before { background-color: var(--color-underweight); }
.info-card li.bmi-underweight strong { color: var(--color-underweight); }
.info-card li.bmi-normal::before { background-color: var(--color-normal); }
.info-card li.bmi-normal strong { color: var(--color-normal); }
.info-card li.bmi-overweight::before { background-color: var(--color-overweight); }
.info-card li.bmi-overweight strong { color: var(--color-overweight); }
.info-card li.bmi-obese-1::before { background-color: var(--color-obese-1); }
.info-card li.bmi-obese-1 strong { color: var(--color-obese-1); }
.info-card li.bmi-obese-2::before { background-color: var(--color-obese-2); }
.info-card li.bmi-obese-2 strong { color: var(--color-obese-2); }
.info-card li.bmi-obese-3::before { background-color: var(--color-obese-3); }
.info-card li.bmi-obese-3 strong { color: var(--color-obese-3); }

.intro-link {
    font-size: 0.875rem;
    margin-top: -1rem;
    text-align: center;
}

.intro-link a {
    color: var(--main-color);
    text-decoration: none;
    font-weight: 600;
}

.intro-link a:hover {
    text-decoration: underline;
}

.input-group {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.form-field {
    margin-bottom: 1.5rem;
}

.button-group {
    margin-top: 1rem;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.btn {
    width: 100%;
    background-color: var(--main-color);
    color: var(--color-white);
    font-weight: bold;
    padding: 0.875rem 1rem;
    border: none;
    border-radius: 0.5rem;
    box-shadow: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -1px rgba(0,0,0,0.06);
    transition: background-color 0.3s;
    cursor: pointer;
    font-size: 1.125rem;
}

.btn:hover {
    background-color: var(--secondary-color);
}

.btn-secondary {
    background-color: var(--tertiary-background);
    color: var(--color-text-secondary);
    box-shadow: none;
}

.btn-secondary:hover {
    background-color: #d1d5db;
}

.unit-toggle {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.tab-button {
    padding: 0.75rem;
    border: none;
    background-color: var(--main-background);
    color: var(--main-color);
    font-weight: bold;
    font-size: 0.875rem;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s ease-in-out;
}

.tab-button:hover {
     background-color: #dbeafe;
}

.tab-button.active {
    background-color: var(--main-color);
    color: var(--color-white);
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

#result-display {
    padding: 2rem;
}

.result-content {
    text-align: center;
}

#bmi-value {
    font-size: 3rem;
    font-weight: 700;
    line-height: 1;
}

#bmi-category {
    font-size: 1.125rem;
    font-weight: 600;
    margin-top: 0.5rem;
}

#bmi-range {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    margin-top: 0.25rem;
}

.disclaimer {
    font-size: 0.75rem;
    margin-top: 1.5rem;
    margin-bottom: 0;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
    text-align: left;
}

.bmi-gauge-container {
    margin-bottom: 1.5rem;
    position: relative;
}

.bmi-gauge-container .gauge-indicator {
    transition: transform 0.7s cubic-bezier(0.68, -0.55, 0.27, 1.55);
    transform-origin: center;
}

.custom-alert {
    position: fixed;
    top: 1rem;
    right: 1rem;
    background-color: var(--color-error-light);
    border: 1px solid var(--color-error-dark);
    color: var(--color-error-dark);
    padding: 1rem 1.5rem;
    border-radius: 0.5rem;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    z-index: 1000;
    font-weight: 600;
    opacity: 0;
    transform: translateX(100%);
    animation: slideInAndFadeOut 3s forwards;
}

@keyframes slideInAndFadeOut {
    0% { opacity: 0; transform: translateX(100%); }
    15% { opacity: 1; transform: translateX(0); }
    85% { opacity: 1; transform: translateX(0); }
    100% { opacity: 0; transform: translateX(100%); }
}

.bmi-underweight { color: var(--color-underweight); }
.bmi-normal { color: var(--color-normal); }
.bmi-overweight { color: var(--color-overweight); }
.bmi-obese-1 { color: var(--color-obese-1); }
.bmi-obese-2 { color: var(--color-obese-2); }
.bmi-obese-3 { color: var(--color-obese-3); }

/* Hide number input spinners */
input[type=number]::-webkit-inner-spin-button,
input[type=number]::-webkit-outer-spin-button {
    -webkit-appearance: none;
    margin: 0;
}
input[type=number] {
    appearance: textfield;
    -moz-appearance: textfield;
}

/* Mobile Responsiveness */
@media (max-width: 480px) {
    .card-content,
    #result-display,
    .info-card {
        padding: 1.5rem;
    }

    #bmi-value {
        font-size: 2.5rem;
    }

    .input-group,
    .button-group,
    .unit-toggle {
        grid-template-columns: 1fr;
    }

    .btn {
        padding: 0.75rem 1rem;
        font-size: 1rem;
    }
}

@media (max-width: 360px) {
    .card-content,
    #result-display,
    .info-card {
        padding: 1rem;
    }

    #bmi-value {
        font-size: 2.25rem;
    }

    .info-card li {
        font-size: 0.85rem;
    }
}