* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
    background-color: #f5f5f5;
    color: #333;
    line-height: 1.6;
}

.container {
    max-width: 600px;
    margin: 50px auto;
    padding: 30px;
    background-color: #fff;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    text-align: center;
}

h1 {
    margin-bottom: 20px;
    color: #128C7E;
}

p {
    margin-bottom: 15px;
}

.btn {
    display: inline-block;
    background-color: #25D366;
    color: white;
    padding: 12px 24px;
    border-radius: 30px;
    text-decoration: none;
    font-weight: bold;
    transition: all 0.3s;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    margin-top: 10px;
}

.btn:hover {
    background-color: #128C7E;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

.hidden {
    display: none;
}

#loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 200px;
}

.spinner {
    border: 4px solid rgba(0, 0, 0, 0.1);
    width: 36px;
    height: 36px;
    border-radius: 50%;
    border-left-color: #25D366;
    animation: spin 1s linear infinite;
    margin-bottom: 20px;
}

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

.countdown {
    margin-top: 20px;
    font-size: 0.9rem;
    color: #666;
}

#file-name {
    background-color: #f5f5f5;
    padding: 10px;
    border-radius: 5px;
    font-family: monospace;
    margin: 15px 0;
}

#error-container {
    color: #d9534f;
}

#error-container h1 {
    color: #d9534f;
}

@media (max-width: 768px) {
    .container {
        margin: 20px;
        padding: 20px;
    }
}