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

:root {
    --primary-color: #6366f1;
    --secondary-color: #ec4899;
    --success-color: #10b981;
    --error-color: #ef4444;
    --warning-color: #f59e0b;
    --dark-bg: #0f172a;
    --light-bg: #f8fafc;
    --card-bg: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.15);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
        'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue',
        sans-serif;
    background: linear-gradient(135deg, var(--dark-bg) 0%, #1e3a8a 100%);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

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

.card {
    background: var(--card-bg);
    border-radius: 16px;
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: 30px 20px;
    text-align: center;
}

.header h1 {
    font-size: 28px;
    margin-bottom: 8px;
    font-weight: 700;
}

.header p {
    font-size: 14px;
    opacity: 0.9;
}

/* MODO SELEÇÃO DE VALOR */
.mode-selection {
    padding: 30px 20px;
}

.mode-selection h2 {
    font-size: 18px;
    margin-bottom: 20px;
    color: var(--text-primary);
    text-align: center;
}

.amount-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-bottom: 30px;
}

.amount-btn {
    padding: 16px 12px;
    background: var(--light-bg);
    color: var(--primary-color);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    font-family: inherit;
}

.amount-btn:hover {
    border-color: var(--primary-color);
    background: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.amount-btn:active {
    transform: translateY(0);
}

.custom-amount {
    border-top: 1px solid var(--border-color);
    padding-top: 20px;
}

.custom-amount label {
    display: block;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-primary);
    font-size: 14px;
}

.input-group {
    display: flex;
    gap: 8px;
    align-items: center;
}

.currency {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 16px;
}

.input-group input {
    flex: 1;
    padding: 10px 12px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 14px;
    transition: all 0.3s ease;
    font-family: inherit;
}

.input-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.btn-custom {
    padding: 10px 20px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    white-space: nowrap;
}

.btn-custom:hover {
    background: #4f46e5;
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.btn-custom:active {
    transform: translateY(0);
}

/* FORMULÁRIO */
.form {
    padding: 30px 20px;
}

.form-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
    padding-bottom: 16px;
    border-bottom: 2px solid var(--border-color);
}

.form-header h2 {
    font-size: 18px;
    color: var(--text-primary);
    margin: 0;
}

.btn-back {
    background: var(--light-bg);
    color: var(--primary-color);
    border: 1px solid var(--border-color);
    padding: 8px 12px;
    border-radius: 6px;
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-back:hover {
    background: var(--primary-color);
    color: white;
}

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

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

.form-group input {
    width: 100%;
    padding: 12px 14px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 14px;
    transition: all 0.3s ease;
    font-family: inherit;
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-group input::placeholder {
    color: var(--text-secondary);
}

.form-group input[readonly] {
    background: var(--light-bg);
    cursor: not-allowed;
}

.btn-refresh {
    position: absolute;
    right: 12px;
    top: 40px;
    background: none;
    border: none;
    font-size: 18px;
    cursor: pointer;
    padding: 4px 8px;
    border-radius: 4px;
    transition: all 0.3s ease;
}

.btn-refresh:hover {
    background: var(--light-bg);
    transform: rotate(180deg);
}

.btn-submit {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: var(--shadow);
    margin-top: 10px;
}

.btn-submit:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

.btn-submit:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.loading {
    padding: 40px 20px;
    text-align: center;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 16px;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

.loading p {
    color: var(--text-secondary);
    font-size: 14px;
}

.result {
    padding: 30px 20px;
    text-align: center;
}

.success-message {
    background: #d1fae5;
    color: #065f46;
    padding: 12px 16px;
    border-radius: 8px;
    margin-bottom: 20px;
    font-size: 14px;
    font-weight: 600;
}

.qr-container {
    margin: 30px 0;
    padding: 20px;
    background: var(--light-bg);
    border-radius: 12px;
    border: 2px dashed var(--border-color);
}

.qr-image {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
}

.transaction-info {
    background: var(--light-bg);
    padding: 20px;
    border-radius: 8px;
    margin: 20px 0;
    text-align: left;
}

.transaction-info h3 {
    font-size: 16px;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.info-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 0;
    border-bottom: 1px solid var(--border-color);
    font-size: 13px;
}

.info-item:last-child {
    border-bottom: none;
}

.info-item .label {
    font-weight: 600;
    color: var(--text-secondary);
}

.info-item .value {
    color: var(--text-primary);
    word-break: break-all;
    text-align: right;
    max-width: 50%;
}

.copy-container {
    display: flex;
    gap: 8px;
    margin-top: 8px;
}

.copy-input {
    flex: 1;
    padding: 8px 12px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 12px;
    font-family: 'Courier New', monospace;
    background: white;
}

.btn-copy {
    padding: 8px 16px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    white-space: nowrap;
}

.btn-copy:hover {
    background: #4f46e5;
    transform: translateY(-1px);
}

.btn-reset {
    width: 100%;
    padding: 12px;
    background: var(--light-bg);
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-top: 16px;
}

.btn-reset:hover {
    background: var(--primary-color);
    color: white;
}

.error {
    padding: 20px;
    background: #fee2e2;
    border-left: 4px solid var(--error-color);
    border-radius: 8px;
    margin: 20px;
}

.error p {
    color: #991b1b;
    margin-bottom: 16px;
    font-size: 14px;
    word-break: break-word;
}

.error .btn-reset {
    margin-top: 12px;
    margin-bottom: 0;
    background: var(--error-color);
    color: white;
    border-color: var(--error-color);
}

.error .btn-reset:hover {
    background: #dc2626;
}

.footer {
    text-align: center;
    padding: 20px;
    color: rgba(255, 255, 255, 0.7);
    font-size: 12px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

@media (max-width: 480px) {
    .header {
        padding: 20px 16px;
    }

    .header h1 {
        font-size: 24px;
    }

    .amount-grid {
        grid-template-columns: 1fr;
    }

    .form-header {
        flex-direction: column;
        gap: 12px;
        align-items: flex-start;
    }

    .form-header h2 {
        width: 100%;
    }

    .btn-back {
        width: 100%;
        text-align: center;
    }

    .form {
        padding: 20px 16px;
    }

    .result {
        padding: 20px 16px;
    }

    .transaction-info {
        padding: 16px;
    }

    .info-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 6px;
    }

    .info-item .value {
        max-width: 100%;
        text-align: left;
    }
}