#istp-container {
    width: 100%;
    max-width: 450px;
    margin: auto;
    text-align: center;
    font-family: Arial, sans-serif;
}

.test-group {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 15px;
    margin: 20px 0;
}

.test-card {
    background: #f2f2f2;
    padding: 20px;
    border-radius: 12px;
    box-shadow: 0px 0px 4px rgba(0,0,0,0.1);
}

.label {
    display: block;
    font-size: 14px;
    opacity: .7;
    margin-bottom: 8px;
}

#startBtn {
    padding: 12px 25px;
    background: #0078ff;
    color: #fff;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 16px;
}