body {
    font-family: Arial, sans-serif;
    background-color: white; /* White background */
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}

#app {
    border: 1px solid black; /* Black border */
    padding: 15px;
    background-color: white;
    width: 45%;
    max-width: 600px;
    border-radius: 15px;
}

.tab {
    display: flex;
    justify-content: center;
    margin-bottom: 15px;
}

.tab button {
    padding: 7px 15px;
    margin: 0 4px;
    border: 1px solid #ddd;
    background-color: transparent;
    cursor: pointer;
    transition: background-color 0.3s, color 0.3s;
    border-radius: 5px;
    font-size: 14px;
}

.tab button:focus {
    outline: none;
    background-color: #ddd;
    color: black;
}

.date-display, .input-container {
    margin: 15px 0;
    font-size: 16px;
    border: 1px solid #ddd;
    padding: 8px;
    border-radius: 10px;
}

input[type=date], input[type=number], button {
    padding: 8px;
    margin: 8px 0;
    border: 1px solid #ddd;
    background-color: #fff;
    width: calc(100% - 16px);
    box-sizing: border-box;
    font-size: 14px;
}

button {
    background-color: transparent;
    color: black;
    cursor: pointer;
    transition: background-color 0.3s, color 0.3s;
}

button:hover {
    background-color: #ddd;
}

/* Hide the second view by default */
#resultingDateView, #daysSince1978View {
    display: none;
}

.input-container {
    display: flex;
    flex-direction: column;
    align-items: center;
}