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

:root {
    --bg-primary: #0a0a0f;
    --bg-secondary: #111118;
    --bg-tertiary: #1a1a24;
    --card-bg: rgba(26, 26, 36, 0.9);
    --card-border: rgba(255, 255, 255, 0.1);
    --text-primary: #ffffff;
    --text-secondary: #a0a0b0;
    --text-muted: #6b6b7f;
    --accent-blue: #0070ba;
    --border-color: rgba(255, 255, 255, 0.1);
    --border-hover: rgba(255, 255, 255, 0.2);
    --success-color: #10b981;
    --accent-gold: #fbbf24;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: var(--bg-primary);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    width: 100%;
    max-width: 500px;
}

.payment-card {
    background: var(--card-bg);
    backdrop-filter: blur(10px);
    border-radius: 16px;
    padding: 0;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5);
    border: 1px solid var(--card-border);
    overflow: hidden;
}

.card-header {
    background: rgba(0, 112, 186, 0.1);
    padding: 35px 35px 25px;
    text-align: center;
    color: var(--text-primary);
    border-bottom: 1px solid var(--border-color);
}

.logo-container {
    margin-bottom: 20px;
}

.logo {
    max-width: 160px;
    height: auto;
    display: inline-block;
}

h1 {
    color: var(--text-primary);
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 8px;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 14px;
    font-weight: 400;
}

.form-section {
    padding: 35px;
}

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

label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-primary);
    font-weight: 600;
    font-size: 14px;
}

input[type="number"],
input[type="text"],
select {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 16px;
    line-height: 1.5;
    transition: all 0.2s ease;
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
    font-weight: 500;
    box-sizing: border-box;
    height: 44px;
}

input[type="number"]:hover,
input[type="text"]:hover,
select:hover {
    border-color: var(--border-hover);
}

input[type="number"]:focus,
input[type="text"]:focus,
select:focus {
    outline: none;
    border-color: var(--accent-blue);
    box-shadow: 0 0 0 3px rgba(0, 112, 186, 0.1);
}

input::placeholder {
    color: var(--text-muted);
}

input[readonly] {
    background-color: rgba(0, 112, 186, 0.1);
    cursor: not-allowed;
    font-weight: 700;
    color: var(--text-primary);
    font-size: 18px;
    border-color: var(--accent-blue);
}

select {
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23a0a0b0' d='M6 9L1 4h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 16px center;
    padding-right: 40px;
}

.fee-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 14px 16px;
    background: rgba(251, 191, 36, 0.1);
    border-radius: 8px;
    margin-bottom: 20px;
    border: 1px solid rgba(251, 191, 36, 0.2);
}

.fee-label {
    color: var(--accent-gold);
    font-weight: 600;
    font-size: 14px;
}

.fee-value {
    color: var(--accent-gold);
    font-weight: 700;
    font-size: 16px;
    font-family: 'Courier New', monospace;
}

.button-container {
    padding: 0 35px 20px;
}

.paypal-button {
    width: 100%;
    padding: 12px 16px;
    background: var(--accent-blue);
    color: white;
    border: 1px solid var(--accent-blue);
    border-radius: 8px;
    font-size: 16px;
    font-weight: 700;
    line-height: 1.5;
    cursor: pointer;
    transition: all 0.2s ease;
    box-sizing: border-box;
    height: 44px;
    text-align: center;
    display: block;
}

.paypal-button:hover {
    background: #0085d1;
    border-color: #0085d1;
    box-shadow: 0 4px 12px rgba(0, 112, 186, 0.4);
}

.paypal-button:active {
    transform: translateY(0);
}

.paypal-button:disabled {
    background: var(--bg-tertiary);
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
    color: var(--text-muted);
}

.security-note {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    margin-top: 0;
    padding: 20px 35px;
    border-top: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 12px;
    font-weight: 500;
}

.security-note svg {
    color: var(--success-color);
    flex-shrink: 0;
}

.copyright {
    margin-top: 30px;
    text-align: center;
    padding: 20px;
}

.copyright p {
    color: var(--text-secondary);
    font-size: 12px;
    margin: 0;
}

/* Responsive Design */
@media (max-width: 600px) {
    .payment-card {
        border-radius: 12px;
    }
    
    .card-header {
        padding: 30px 24px 20px;
    }
    
    .form-section {
        padding: 30px 24px;
    }
    
    h1 {
        font-size: 24px;
    }
    
    .logo {
        max-width: 140px;
    }
    
    .button-container {
        padding: 0 24px 20px;
    }
    
    .paypal-button {
        padding: 12px 16px;
        font-size: 16px;
    }
    
    .security-note {
        padding: 20px 24px;
    }
    
    .copyright {
        margin-top: 20px;
        padding: 15px;
    }
}

@media (max-width: 400px) {
    body {
        padding: 10px;
    }
    
    .card-header {
        padding: 24px 20px 18px;
    }
    
    .form-section {
        padding: 24px 20px;
    }
    
    h1 {
        font-size: 22px;
    }
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--bg-tertiary);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--border-hover);
}