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

body {
    background: linear-gradient(135deg, #1a1a1a 0%, #2d2d2d 100%);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
    color: #ffffff;
}

.container {
    text-align: center;
    max-width: 1000px;
    width: 100%;
    padding: 40px 20px;
}

h1 {
    margin-bottom: 50px;
    font-size: 2.5em;
    color: #ffffff;
    font-weight: 300;
    letter-spacing: 1px;
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

.cards {
    display: flex;
    justify-content: center;
    gap: 25px;
    flex-wrap: wrap;
    margin-bottom: 20px;
}

.card {
    background: linear-gradient(145deg, #2a2a2a 0%, #3a3a3a 100%);
    border: 2px solid #404040;
    border-radius: 16px;
    padding: 35px 20px;
    width: 280px;
    box-shadow: 0 8px 25px rgba(0,0,0,0.3);
    cursor: pointer;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    display: flex;
    flex-direction: column;
    align-items: center;
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #0070ba, #00a8ff);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.card input[type="radio"] {
    position: absolute;
    top: 20px;
    left: 20px;
    width: 22px;
    height: 22px;
    cursor: pointer;
    accent-color: #0070ba;
}

.card:hover {
    transform: translateY(-12px);
    box-shadow: 0 15px 35px rgba(0,0,0,0.4);
    border-color: #0070ba;
}

.card:hover::before {
    transform: scaleX(1);
}

.card input[type="radio"]:checked + .card-content {
    background: rgba(0, 112, 186, 0.1);
    border-radius: 12px;
    padding: 10px;
    margin: -10px;
}

.card-content {
    transition: all 0.3s ease;
    padding: 10px;
}

.card-content h2 {
    font-size: 1.6em;
    margin-bottom: 15px;
    color: #0070ba;
    font-weight: 600;
}

.card-content p {
    font-size: 1em;
    color: #cccccc;
    line-height: 1.5;
}

#startBtn {
    margin-top: 50px;
    background: linear-gradient(135deg, #0070ba 0%, #00a8ff 100%);
    color: #ffffff;
    border: none;
    padding: 16px 45px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1.1em;
    font-weight: 600;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 112, 186, 0.3);
    letter-spacing: 0.5px;
}

#startBtn:hover:enabled {
    background: linear-gradient(135deg, #005c99 0%, #0088cc 100%);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 112, 186, 0.4);
}

#startBtn:active:enabled {
    transform: translateY(0);
}

#startBtn:disabled {
    background: #4a4a4a;
    cursor: not-allowed;
    box-shadow: none;
    transform: none;
}