/* Basic Reset / Box Sizing */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html, body {
    height: 100%;
    font-family: sans-serif;
    background-color: #f4f4f4; /* Light background */
}

body {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding-top: 20px;
}

#app-container {
    width: 100%;
    max-width: 400px; /* Typical mobile width */
    padding: 15px;
}

/* Utility Class */
.hidden {
    display: none !important;
}

/* Loading Indicator Styles (Basic) */
#loading-indicator {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5); /* Dim overlay */
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    color: white;
}

#loading-indicator .spinner {
    /* Basic spinner - replace with actual CSS animation later if needed */
    border: 4px solid #f3f3f3;
    border-top: 4px solid #3498db;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin-bottom: 10px;
}

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

/* Error Banner Styles (Basic) */
.error-banner {
    background-color: #e74c3c; /* Red */
    color: white;
    padding: 10px;
    margin-bottom: 15px;
    text-align: center;
    border-radius: 4px;
    width: 100%;
    max-width: 400px; /* Match app container */
}

/* Screen Container Styles (Basic) */
.screen {
    background-color: #ffffff;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    text-align: center;
}

/* Add basic button styling */
button {
    display: block;
    width: 100%;
    padding: 15px;
    margin-bottom: 10px;
    border: none;
    border-radius: 5px;
    font-size: 16px;
    cursor: pointer;
    background-color: #3498db; /* Primary Blue */
    color: white;
    font-weight: bold;
}

button:last-child {
    margin-bottom: 0;
}

button:hover {
    opacity: 0.9;
}

/* Add basic input styling */
input[type="email"] {
    display: block;
    width: 100%;
    padding: 10px;
    margin-bottom: 15px;
    border: 1px solid #ccc;
    border-radius: 4px;
    font-size: 16px;
}

label { /* Style for potential label if added */
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
    text-align: left;
}