/* --- Variables & Basic Reset --- */
:root {
    --bg-dark: #1a1d21; /* Dark background */
    --bg-card: #2a2d31; /* Slightly lighter for cards/elements */
    --bg-input: #3a3d41;
    --text-light: #e0e0e0; /* Light text */
    --text-secondary: #a0a0a0; /* Dimmer text */
    --accent-blue: #39C3FF;
    --accent-blue-darker: #00aeff;
    --danger-red: #ff4d4d;
    --border-color: #444;
    --font-family: 'Segoe UI', 'Inter', 'Open Sans', sans-serif;
    --border-radius: 8px;
}

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

html {
    font-size: 16px; /* Base font size */
}

body {
    font-family: var(--font-family);
    background-color: var(--bg-dark);
    color: var(--text-light);
    overscroll-behavior: none; /* Prevent pull-to-refresh issues */
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    width: 100%;
}

/* --- App Container --- */
#app-container {
    width: 100%;
    max-width: 480px; /* Mobile-like max width on desktop */
    height: 100vh; /* Full viewport height */
    display: flex;
    flex-direction: column;
    background-color: var(--bg-dark);
    border-left: 1px solid var(--border-color); /* Subtle border on desktop */
    border-right: 1px solid var(--border-color);
    overflow: hidden; /* Prevent body scroll */
}

/* --- Main Content Area --- */
#main-content {
    flex-grow: 1; /* Takes available space */
    position: relative; /* For absolute positioning inside if needed */
    overflow-y: hidden; /* Panes will handle their own scroll */
    display: flex; /* To manage panes */
}

/* --- Pane Styling --- */
.app-pane {
    width: 100%;
    height: 100%;
    display: none; /* Hide panes by default */
    flex-direction: column;
    overflow: hidden;
}

.app-pane.active-pane {
    display: flex; /* Show the active pane */
}

.pane-header {
    padding: 15px;
    background-color: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
    flex-shrink: 0; /* Prevent header from shrinking */
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.pane-header h1, .pane-header h2 {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text-light);
}
.pane-content { /* For panes with headers and scrollable content */
    padding: 15px;
    overflow-y: auto;
    flex-grow: 1;
}

/* --- Pane 1: Group List --- */
#group-list-view {
    /* No header, list starts immediately */
}
.group-list {
    list-style: none;
    padding: 10px;
    overflow-y: auto;
    flex-grow: 1;
}

.group-card {
    display: flex;
    align-items: center;
    background-color: var(--bg-card);
    padding: 12px 15px;
    margin-bottom: 8px;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: background-color 0.2s ease, box-shadow 0.2s ease;
}

.group-card:hover {
    background-color: #35383d;
    box-shadow: 0 0 10px rgba(57, 195, 255, 0.2); /* Soft glow */
}

.group-icon {
    width: 45px;
    height: 45px;
    border-radius: 50%;
    background-color: var(--bg-input); /* Placeholder color */
    margin-right: 15px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5rem;
    color: var(--text-secondary);
    flex-shrink: 0;
}
.group-icon.placeholder-icon::before {
    content: ''; /* Placeholder - could be initials or SVG later */
}
.group-icon.add-icon {
     background-color: transparent;
     border: 2px dashed var(--text-secondary);
     color: var(--text-secondary);
}

.group-info {
    display: flex;
    flex-direction: column;
    overflow: hidden; /* Prevent text overflow */
}

.group-name {
    font-weight: 600;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    margin-bottom: 2px;
    color: var(--text-light);
}

.group-preview {
    font-size: 0.9rem;
    color: var(--text-secondary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.add-group-card .group-name {
    color: var(--text-secondary);
    font-weight: normal;
}


/* --- Pane 2: Chat View --- */
.chat-header button {
    background: none;
    border: none;
    color: var(--accent-blue);
    font-size: 1.5rem; /* Make buttons tappable */
    cursor: pointer;
    padding: 5px 10px;
}
.chat-header button:hover {
    opacity: 0.8;
}
.chat-header h2 {
    text-align: center;
    flex-grow: 1;
    margin: 0 10px; /* Space around title */
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

#message-list {
    flex-grow: 1; /* Takes up available space */
    overflow-y: auto; /* Enable scrolling for messages */
    padding: 15px 10px;
    display: flex;
    flex-direction: column;
}

.message {
    max-width: 75%; /* Max width of message bubbles */
    padding: 8px 12px;
    border-radius: var(--border-radius);
    margin-bottom: 10px;
    word-wrap: break-word; /* Break long words */
}

.message .sender-name {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--accent-blue); /* Example: Highlight sender */
    display: block;
    margin-bottom: 3px;
}

.message .message-content {
    font-size: 1rem;
    line-height: 1.4;
    margin: 0; /* Reset default p margin */
}

.message .timestamp {
    font-size: 0.75rem;
    color: var(--text-secondary);
    display: block;
    text-align: right;
    margin-top: 4px;
}

.message.self {
    background-color: var(--accent-blue);
    color: var(--bg-dark); /* Dark text on accent bg */
    align-self: flex-end; /* Align to the right */
    margin-left: auto;
}
.message.self .timestamp {
     color: rgba(0, 0, 0, 0.6); /* Darker timestamp */
}
/* Self messages don't need sender name */
.message.self .sender-name {
    display: none;
}


.message.other {
    background-color: var(--bg-card);
    color: var(--text-light);
    align-self: flex-start; /* Align to the left */
    margin-right: auto;
}
.message.other .sender-name {
    color: var(--accent-blue); /* Or another color */
}


/* --- Chat Input Area --- */
.message-input-area {
    display: flex;
    padding: 10px;
    background-color: var(--bg-card);
    border-top: 1px solid var(--border-color);
    flex-shrink: 0; /* Prevent shrinking */
}

#message-input {
    flex-grow: 1;
    padding: 10px 15px;
    border: none;
    border-radius: var(--border-radius);
    background-color: var(--bg-input);
    color: var(--text-light);
    font-size: 1rem;
    margin-right: 10px;
}
#message-input::placeholder {
    color: var(--text-secondary);
}
#message-input:focus {
    outline: none;
    box-shadow: 0 0 0 2px var(--accent-blue);
}

#send-button {
    padding: 10px 20px;
    background-color: var(--accent-blue);
    color: var(--bg-dark);
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-weight: 600;
    transition: background-color 0.2s ease;
}

#send-button:hover {
    background-color: var(--accent-blue-darker);
}

/* --- Pane 3: Group Info / Members --- */
#group-info-view h3 {
    margin-top: 20px;
    margin-bottom: 10px;
    color: var(--accent-blue);
    font-size: 1rem;
    font-weight: 600;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 5px;
}
#group-info-view h3:first-of-type {
    margin-top: 0;
}


#member-list {
    list-style: none;
    padding-left: 5px;
}

#member-list li {
    padding: 6px 0;
    color: var(--text-light);
}
.member-name {
     font-size: 0.95rem;
}

#group-info-view hr {
    border: none;
    border-top: 1px solid var(--border-color);
    margin: 20px 0;
}

.settings-section p, .setting-item {
    margin-bottom: 15px;
    font-size: 0.95rem;
}
.settings-section code {
    background-color: var(--bg-input);
    padding: 3px 6px;
    border-radius: 4px;
    font-family: monospace;
}
.settings-section button.inline-button {
    background: none;
    border: 1px solid var(--accent-blue);
    color: var(--accent-blue);
    padding: 2px 8px;
    font-size: 0.8rem;
    border-radius: 4px;
    margin-left: 10px;
    cursor: pointer;
}
.settings-section button:disabled {
    background-color: var(--bg-input) !important;
    color: var(--text-secondary) !important;
    border-color: var(--text-secondary) !important;
    cursor: not-allowed;
    opacity: 0.6;
}
.settings-section .danger-button:disabled {
     border-color: var(--text-secondary) !important;
     color: var(--text-secondary) !important;
     background-color: transparent !important;
}

.setting-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.setting-item label {
    color: var(--text-secondary);
}
.placeholder-toggle { /* Style placeholder toggles */
    display: inline-block;
    padding: 4px 10px;
    background-color: var(--bg-input);
    color: var(--text-secondary);
    border-radius: 12px; /* Pill shape */
    font-size: 0.85rem;
    font-weight: 500;
    opacity: 0.7;
}

.danger-button {
    background-color: transparent;
    border: 1px solid var(--danger-red);
    color: var(--danger-red);
    padding: 8px 15px;
    border-radius: var(--border-radius);
    cursor: pointer;
    width: 100%; /* Make block level */
    text-align: center;
    margin-top: 10px;
}
.danger-button:hover:not(:disabled) {
    background-color: rgba(255, 77, 77, 0.1);
}


/* --- Bottom Navigation --- */
#bottom-nav {
    display: flex;
    border-top: 1px solid var(--border-color);
    background-color: var(--bg-card);
    flex-shrink: 0; /* Prevent shrinking */
}

.nav-button {
    flex-grow: 1;
    padding: 15px 10px;
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 0.9rem;
    cursor: pointer;
    text-align: center;
    transition: color 0.2s ease, border-top 0.2s ease;
    border-top: 3px solid transparent; /* Placeholder for active indicator */
}
.nav-button:disabled {
    color: #666; /* Dim disabled buttons */
    cursor: not-allowed;
    border-top-color: transparent !important; /* Ensure no active border */
}


.nav-button.active {
    color: var(--accent-blue);
    font-weight: 600;
    border-top-color: var(--accent-blue);
}

.nav-button:hover:not(.active):not(:disabled) {
    color: var(--text-light);
}


/* --- Utility Classes --- */
.hidden {
    display: none !important; /* Force hide */
}

/* --- Basic Responsiveness (Optional: Refine for Desktop if needed) --- */
@media (min-width: 768px) {
    /* On larger screens, maybe constrain width less aggressively */
    #app-container {
       /* max-width: 600px; */ /* Example: Slightly wider */
       /* Could potentially show multiple panes, but brief emphasizes mobile toggle */
        box-shadow: 0 0 20px rgba(0,0,0,0.3); /* More pronounced shadow */
    }
    html {
        font-size: 17px; /* Slightly larger base font */
    }

}