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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background: #f5f5f5;
    color: #333;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

main {
    background: #fff;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 420px;
}

h1 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    text-align: center;
}

label {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.amount-input {
    display: flex;
    align-items: center;
    border: 1px solid #ccc;
    border-radius: 4px;
    padding: 0.5rem 0.75rem;
    margin-bottom: 1.5rem;
}

.currency-symbol {
    font-size: 1rem;
    color: #666;
    margin-right: 0.25rem;
}

.amount-input input {
    border: none;
    outline: none;
    font-size: 1rem;
    width: 100%;
}

#paypal-button-container {
    margin-bottom: 1rem;
}

#message {
    margin-top: 1rem;
    padding: 0.75rem;
    border-radius: 4px;
    text-align: center;
    font-size: 0.875rem;
}

#message.error {
    background: #fee;
    color: #c00;
}

#message.success {
    background: #efe;
    color: #0a0;
}

.hidden {
    display: none;
}

.success-message {
    text-align: center;
    padding: 2rem 0;
}

.success-message h2 {
    color: #0a0;
    margin-bottom: 0.5rem;
}