body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: #0a0a0f;
    color: #fff;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    padding: 20px;
}

.container {
    max-width: 500px;
    width: 100%;
    background: #1a1a2e;
    border-radius: 20px;
    padding: 40px 30px;
    text-align: center;
}

h1 {
    font-size: 28px;
    margin-bottom: 10px;
    background: linear-gradient(45deg, #ff6b6b, #ffd93d);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.subtitle {
    color: #aaa;
    font-size: 16px;
    margin-bottom: 30px;
}

.key-box {
    background: #0d0d1a;
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 25px;
}

.key {
    font-size: 28px;
    font-weight: bold;
    color: #ffd93d;
    letter-spacing: 4px;
}

.price {
    font-size: 36px;
    font-weight: bold;
    color: #fff;
}

.one-time {
    display: block;
    font-size: 14px;
    color: #888;
}

.form-group {
    margin-bottom: 20px;
    text-align: left;
}

.form-group input {
    width: 100%;
    padding: 12px;
    border-radius: 10px;
    border: none;
    background: #0d0d1a;
    color: #fff;
    font-size: 16px;
    box-sizing: border-box;
}

.btn-pay {
    width: 100%;
    padding: 16px;
    font-size: 18px;
    font-weight: bold;
    background: linear-gradient(45deg, #ff6b6b, #ffd93d);
    border: none;
    border-radius: 12px;
    color: #0a0a0f;
    cursor: pointer;
}

.hint {
    font-size: 13px;
    color: #666;
    margin-top: 20px;
}