.vo2-calculator-wrapper {
    max-width: 500px;
    margin: 20px 0;
    padding: 20px;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    background: #f9f9f9;
    font-family: inherit;
}

.vo2-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
}

.vo2-input-group {
    display: flex;
    flex-direction: column;
}

.vo2-input-group.vo2-full-width {
    grid-column: span 2;
}

.vo2-input-group label {
    font-size: 0.9em;
    font-weight: 600;
    margin-bottom: 5px;
    color: #333;
}

.vo2-input-group input, 
.vo2-input-group select {
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
    font-size: 16px;
    width: 100%;
}

.vo2-time-flex {
    display: flex;
    gap: 10px;
}

.vo2-btn {
    width: 100%;
    margin-top: 20px;
    padding: 12px;
    background-color: #0954B9;
    color: #fff;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
    transition: background 0.3s;
}

.vo2-btn:hover {
    background-color: #555;
}

.vo2-result-box {
    margin-top: 20px;
    padding: 15px;
    background: #fff;
    border-left: 5px solid #333;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

#vo2-number {
    font-size: 2em;
    font-weight: bold;
    color: #333;
}

.vo2-unit {
    font-size: 0.9em;
    color: #777;
}

#vo2-classification {
    margin: 5px 0 0 0;
    font-weight: 600;
    font-size: 0.9em;
}

/* Mobile Adjustments */
@media (max-width: 480px) {
    .vo2-grid {
        grid-template-columns: 1fr;
    }
    .vo2-input-group.vo2-full-width {
        grid-column: span 1;
    }
}