* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: #000;
    color: #fff;
    min-height: 100vh;
}

.container {
    width: 100%;
    max-width: 800px;
    margin: 0 auto;
}

.header {
    background: linear-gradient(135deg, #00ff00 0%, #00cc00 100%);
    padding: 20px;
    position: relative;
}

.back-btn {
    display: inline-block;
    color: #000;
    text-decoration: none;
    font-weight: 600;
    margin-bottom: 15px;
    transition: all 0.3s ease;
}

.back-btn:hover {
    transform: translateX(-5px);
}

.header h1 {
    font-size: 36px;
    font-weight: 900;
    letter-spacing: 2px;
    color: #000;
}

.content {
    padding: 40px 20px;
    background: linear-gradient(180deg, #000 0%, #0a0a0a 100%);
    min-height: calc(100vh - 200px);
}

.checkout-card {
    background: #111;
    border: 2px solid #00ff00;
    border-radius: 12px;
    padding: 40px;
    max-width: 500px;
    margin: 0 auto;
    box-shadow: 0 0 30px rgba(0, 255, 0, 0.2);
}

.info-section {
    text-align: center;
    margin-bottom: 30px;
}

.info-section h2 {
    font-size: 24px;
    margin-bottom: 10px;
    color: #00ff00;
}

.description {
    color: #aaa;
    font-size: 14px;
    line-height: 1.6;
}

.form {
    margin: 30px 0;
}

.plans-section {
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 1px solid #333;
}

.plans-section h3 {
    color: #00ff00;
    margin-bottom: 15px;
    font-size: 16px;
}

.plan-option {
    position: relative;
    margin-bottom: 15px;
}

.plan-option input[type="radio"] {
    display: none;
}

.plan-label {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 15px;
    border: 2px solid #333;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
}

.plan-option input[type="radio"]:checked + .plan-label {
    border-color: #00ff00;
    background: rgba(0, 255, 0, 0.1);
    box-shadow: 0 0 15px rgba(0, 255, 0, 0.2);
}

.plan-content {
    display: flex;
    flex-direction: column;
    gap: 5px;
    flex: 1;
}

.plan-name {
    font-weight: 600;
    color: #fff;
    font-size: 14px;
}

.plan-price {
    color: #00ff00;
    font-weight: 700;
    font-size: 16px;
}

.plan-price .original {
    color: #666;
    text-decoration: line-through;
    margin-right: 8px;
    font-size: 14px;
}

.discount-badge {
    position: absolute;
    top: -10px;
    right: 10px;
    background: #ff4444;
    color: #fff;
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 12px;
    font-weight: 700;
}

.checkmark {
    width: 20px;
    height: 20px;
    border: 2px solid #333;
    border-radius: 50%;
    margin-left: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.plan-option input[type="radio"]:checked + .plan-label .checkmark {
    border-color: #00ff00;
    background: #00ff00;
}

.plan-option input[type="radio"]:checked + .plan-label .checkmark::after {
    content: '✓';
    color: #000;
    font-weight: 700;
    font-size: 14px;
}

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

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #fff;
    font-size: 14px;
}

.input-wrapper {
    display: flex;
    align-items: center;
    border: 1px solid #00ff00;
    border-radius: 6px;
    background: #0a0a0a;
    overflow: hidden;
}

.input-wrapper .prefix {
    padding: 0 12px;
    color: #00ff00;
    font-weight: 600;
}

.input-wrapper input {
    flex: 1;
    background: transparent;
    border: none;
    padding: 12px;
    color: #fff;
    font-size: 14px;
    outline: none;
}

.input-wrapper input::placeholder {
    color: #666;
}

.form-group input {
    width: 100%;
    padding: 12px;
    border: 1px solid #00ff00;
    border-radius: 6px;
    background: #0a0a0a;
    color: #fff;
    font-size: 14px;
    transition: all 0.3s ease;
}

.form-group input:focus {
    outline: none;
    border-color: #00ff00;
    box-shadow: 0 0 10px rgba(0, 255, 0, 0.3);
    background: #111;
}

.form-group input::placeholder {
    color: #666;
}

.submit-btn {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, #00ff00 0%, #00cc00 100%);
    color: #000;
    border: none;
    border-radius: 6px;
    font-size: 16px;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-top: 10px;
}

.submit-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(0, 255, 0, 0.4);
}

.submit-btn:active:not(:disabled) {
    transform: translateY(0);
}

.submit-btn:disabled {
    opacity: 0.7;
    cursor: not-allowed;
    animation: pulse-btn 1s infinite;
}

@keyframes pulse-btn {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.02);
    }
}

.benefits {
    margin-top: 30px;
    padding-top: 30px;
    border-top: 1px solid #333;
}

.benefits h3 {
    color: #00ff00;
    margin-bottom: 15px;
    font-size: 16px;
}

.benefits ul {
    list-style: none;
}

.benefits li {
    color: #ccc;
    padding: 8px 0;
    font-size: 14px;
    line-height: 1.6;
}

footer {
    background: #000;
    padding: 30px 20px;
    text-align: center;
    border-top: 2px solid #00ff00;
}

footer p {
    font-size: 12px;
    color: #666;
}

@media (max-width: 600px) {
    .header h1 {
        font-size: 28px;
    }

    .content {
        padding: 20px;
    }

    .checkout-card {
        padding: 25px;
    }

    .info-section h2 {
        font-size: 20px;
    }
}