/* Root UI Variables - Enforcing strict dark theme */
:root {
    --bg-color: #0d1117;
    --container-bg: #161b22;
    --border-color: #30363d;
    --text-primary: #c9d1d9;
    --text-secondary: #8b949e;
    
    /* Bubble Colors */
    --user-msg-bg: #238636;
    --user-msg-text: #ffffff;
    --bot-msg-bg: #21262d;
    --bot-msg-text: #c9d1d9;
    
    /* Core Accents */
    --accent-color: #58a6ff;
    --error-color: #f85149;
    --radius: 18px;
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

/* Chat App Wrapper */
.chat-container {
    width: 100%;
    max-width: 600px;
    height: 90vh; /* Reduced a bit for mobile friendliness */
    max-height: 900px;
    background-color: var(--container-bg);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    box-shadow: 0 20px 50px rgba(0,0,0,0.5);
    position: relative;
}

/* --- Header Section --- */
.chat-header {
    padding: 1.2rem;
    background-color: var(--container-bg);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    z-index: 10;
}

.header-info { display: flex; align-items: center; gap: 1rem; }
.bot-icon { font-size: 1.8rem; color: var(--accent-color); }
.chat-header h2 { font-size: 1.1rem; font-weight: 600; }
.status { font-size: 0.8rem; color: #3fb950; display: flex; align-items: center; gap: 0.4rem; margin-top: 2px;}
.status::before { content: ''; width: 8px; height: 8px; background: #3fb950; border-radius: 50%; display: inline-block; }

.header-controls { display: flex; gap: 0.8rem; }
.icon-btn {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 0.5rem 0.8rem;
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
    font-weight: 500;
}
.icon-btn:hover { background-color: var(--border-color); }

/* Dynamic Modes for Toggle Button */
.text-mode { color: var(--accent-color); border-color: var(--accent-color); }
.text-mode:hover { background-color: rgba(88, 166, 255, 0.1); }
.image-mode { color: #a371f7; border-color: #a371f7; } /* Purple accent for image context */
.image-mode:hover { background-color: rgba(163, 113, 247, 0.1); }

/* --- Chat Viewport & Scrolling --- */
.chat-history {
    flex: 1;
    padding: 1.5rem;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
    scroll-behavior: smooth;
}

.chat-history::-webkit-scrollbar { width: 6px; }
.chat-history::-webkit-scrollbar-track { background: transparent; }
.chat-history::-webkit-scrollbar-thumb { background: var(--border-color); border-radius: 10px; }

/* --- Chat Bubbles --- */
.message { 
    display: flex; 
    flex-direction: column; 
    max-width: 85%; 
    animation: slideIn 0.3s ease-out backwards; 
}
.user-message { align-self: flex-end; align-items: flex-end; }
.bot-message { align-self: flex-start; align-items: flex-start; }

.message-content {
    padding: 0.9rem 1.2rem;
    border-radius: var(--radius);
    line-height: 1.5;
    font-size: 0.95rem;
    word-wrap: break-word;
}

.user-message .message-content {
    background-color: var(--user-msg-bg);
    color: var(--user-msg-text);
    border-bottom-right-radius: 4px;
}

.bot-message .message-content {
    background-color: var(--bot-msg-bg);
    color: var(--bot-msg-text);
    border-bottom-left-radius: 4px;
    border: 1px solid var(--border-color);
}

/* Image payload rendering */
.message-content img {
    max-width: 100%;
    border-radius: 10px;
    margin-top: 0.2rem;
    display: block;
    box-shadow: 0 4px 12px rgba(0,0,0,0.3);
}

.error-content { 
    color: var(--error-color) !important; 
    border-color: var(--error-color) !important; 
}

/* Bonus: Micro Time-Stamping */
.message-timestamp {
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-top: 0.4rem;
    margin-bottom: 0.2rem;
}

/* --- Typing Indicator "Bot is typing" --- */
.typing-indicator {
    padding: 0 1.5rem 1rem 1.5rem;
    display: flex;
    gap: 0.4rem;
    align-items: center;
}
.typing-indicator.hidden { display: none; }

.dot { 
    width: 6px; 
    height: 6px; 
    background-color: var(--text-secondary); 
    border-radius: 50%; 
    animation: bounce 1.4s infinite ease-in-out both; 
}
.dot:nth-child(1) { animation-delay: -0.32s; }
.dot:nth-child(2) { animation-delay: -0.16s; }

@keyframes bounce { 
    0%, 80%, 100% { transform: scale(0); } 
    40% { transform: scale(1); } 
}
@keyframes slideIn { 
    from { opacity: 0; transform: translateY(15px); } 
    to { opacity: 1; transform: translateY(0); } 
}

/* --- Input Bar Area --- */
.chat-input-area {
    padding: 1rem 1.5rem;
    background-color: var(--container-bg);
    border-top: 1px solid var(--border-color);
}

#chat-form { display: flex; gap: 0.8rem; }

#chat-input {
    flex: 1;
    padding: 0.9rem 1.2rem;
    border-radius: 25px;
    border: 1px solid var(--border-color);
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-size: 0.95rem;
    outline: none;
    transition: var(--transition);
}
#chat-input:focus { border-color: var(--accent-color); }
#chat-input::placeholder { color: var(--text-secondary); }

#send-btn {
    width: 45px;
    height: 45px;
    border-radius: 50%;
    border: none;
    background-color: var(--accent-color);
    color: #fff;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: var(--transition);
}

/* Hover and disabled state rules */
#send-btn:hover:not(:disabled) { transform: scale(1.05); }
#send-btn:disabled { 
    background-color: var(--border-color); 
    color: var(--text-secondary); 
    cursor: not-allowed; 
}

/* --- Responsive Adjustments --- */
@media (max-width: 600px) {
    .chat-container { height: 100vh; border-radius: 0; max-height: none; border: none; }
    .header-controls span { display: none; } /* Hide labels on mobile to save space */
}