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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background-color: #f4f6f9;
    color: #333;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.container {
    background-color: #ffffff;
    padding: 2.5rem;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
    text-align: center;
    max-width: 450px;
    width: 90%;
}

h1 {
    font-size: 2.2rem;
    color: #1a202c;
    margin-bottom: 1rem;
}

hr {
    border: 0;
    height: 2px;
    background: linear-gradient(to right, #3182ce, #63b3ed, #3182ce);
    margin: 1.5rem 0;
    border-radius: 2px;
}

#datetime {
    font-size: 1.15rem;
    color: #4a5568;
    font-weight: 500;
}