body {
    font-family: Arial, sans-serif;
    background: #f8fafc;
    margin: 0;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}
.container {
    max-width: 600px;
    margin: 40px auto;
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.07);
    padding: 32px;
}
footer.footer {
    margin-top: auto;
    background: #e5e7eb;
    font-size: 15px;
}
input[type="text"] {
    width: 100%;
    padding: 10px;
    border: 1px solid #d1d5db;
    border-radius: 4px;
    margin-bottom: 16px;
    font-size: 16px;
}
button {
    background: #2563eb;
    color: #fff;
    border: none;
    padding: 10px 24px;
    border-radius: 4px;
    font-size: 16px;
    cursor: pointer;
    transition: background 0.2s;
}
button:disabled {
    background: #a5b4fc;
    cursor: not-allowed;
}
.countdown {
    font-size: 18px;
    color: #f59e42;
    margin-bottom: 12px;
    text-align: center;
}