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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

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

.screen {
    display: none;
    animation: fadeIn 0.3s ease-in;
}

.screen.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.content-box {
    background: white;
    border-radius: 16px;
    padding: 40px 30px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    text-align: center;
}

.icon {
    font-size: 64px;
    margin-bottom: 20px;
    display: block;
}

.icon.success {
    color: #28a745;
    font-size: 80px;
    font-weight: bold;
}

.icon.error {
    color: #dc3545;
    font-size: 64px;
}

h1 {
    font-size: 24px;
    color: #333;
    margin-bottom: 16px;
    line-height: 1.4;
}

.description {
    font-size: 16px;
    color: #666;
    line-height: 1.6;
    margin-bottom: 30px;
}

.btn {
    display: inline-block;
    padding: 14px 28px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.3s;
    margin: 8px;
    min-width: 200px;
}

.btn-primary {
    background: #667eea;
    color: white;
}

.btn-primary:hover {
    background: #5568d3;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

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

.btn-secondary {
    background: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background: #5a6268;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(108, 117, 125, 0.4);
}

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

.spinner {
    border: 4px solid #f3f3f3;
    border-top: 4px solid #667eea;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    animation: spin 1s linear infinite;
    margin: 0 auto 20px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

#loading p,
#sending-screen p {
    color: white;
    font-size: 18px;
    margin-top: 20px;
}

#loading,
#sending-screen {
    text-align: center;
}

#loading .spinner,
#sending-screen .spinner {
    border-top-color: white;
}

/* Responsividade */
@media (max-width: 600px) {
    .content-box {
        padding: 30px 20px;
    }

    h1 {
        font-size: 20px;
    }

    .description {
        font-size: 14px;
    }

    .btn {
        min-width: 100%;
        margin: 8px 0;
    }

    .icon {
        font-size: 48px;
    }

    .icon.success {
        font-size: 64px;
    }
}

/* Estados de botão desabilitado */
.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none !important;
}