/* --- Modern CSS Overhaul --- */

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

:root {
    --bg-color: #121212;
    --surface-color: #1e1e1e;
    --header-bg: rgba(30, 30, 30, 0.7);
    --primary-accent: #007aff;
    --primary-accent-hover: #0056b3;
    --text-primary: #e0e0e0;
    --text-secondary: #a0a0a5;
    --border-color: #383838;
    --user-message-bg: var(--primary-accent);
    --bot-message-bg: #2f2f31;
    --error-bg: #5c2b2b;
    --error-text: #ffcccc;
}

body {
    font-family: 'Inter', sans-serif;
    background: linear-gradient(135deg, #1e1e1e 0%, #121212 100%);
    color: var(--text-primary);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
}

/* Main Chat Container */
.chat-container {
    width: 100%;
    max-width: 1200px; /* increased from 800px */
    height: 90vh;
    background-color: var(--surface-color);
    border-radius: 24px;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.3), 0 0 0 1px rgba(255, 255, 255, 0.05);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    border: 1px solid var(--border-color);
    padding: 0 20px;
}

/* Header */
.chat-header {
    padding: 20px;
    background-color: var(--header-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    flex-shrink: 0;
}

.chat-header h1 {
    font-size: 1.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 20px;
    color: var(--text-primary);
}

.controls-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 15px;
}

@media (min-width: 768px) {
    .chat-container {
        max-width: 1000px;
    }
}
@media (min-width: 1024px) {
    .chat-container {
        max-width: 1200px;
    }
}
@media (min-width: 1440px) {
    .chat-container {
        max-width: 1400px;
    }
}
.system-prompt-group {
    grid-column: 1 / -1;
}

.control-group {
    display: flex;
    flex-direction: column;
}

/* Form Elements Styling */
label {
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 6px;
}

select,
input,
textarea {
    font-family: 'Inter', sans-serif;
    font-size: 0.9rem;
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 10px 12px;
    color: var(--text-primary);
    transition: border-color 0.3s, box-shadow 0.3s;
}

select:focus,
input:focus,
textarea:focus {
    outline: none;
    border-color: var(--primary-accent);
    box-shadow: 0 0 0 3px rgba(0, 122, 255, 0.3);
}

/* Chat Box */
.chat-box {
    flex-grow: 1;
    padding: 20px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 15px;
}

/* Custom Scrollbar */
.chat-box::-webkit-scrollbar { width: 6px; }
.chat-box::-webkit-scrollbar-track { background: transparent; }
.chat-box::-webkit-scrollbar-thumb {
    background-color: #444;
    border-radius: 3px;
}
.chat-box::-webkit-scrollbar-thumb:hover { background-color: #555; }

/* Message Animation */
@keyframes fadeInSlideUp {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Message Styling */
.message-wrapper {
    display: flex;
    align-items: flex-end;
    gap: 10px;
    max-width: 85%;
    animation: fadeInSlideUp 0.4s ease-out;
}

.message-wrapper.user {
    align-self: flex-end;
    flex-direction: row-reverse;
}

.message-wrapper.bot { align-self: flex-start; }

.avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background-color: #333;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.2rem;
    flex-shrink: 0;
    border: 1px solid var(--border-color);
}

.message {
    padding: 12px 18px;
    border-radius: 20px;
    line-height: 1.6;
    word-wrap: break-word;
}

.message.user-message {
    background-color: var(--user-message-bg);
    color: white;
    border-bottom-right-radius: 5px;
}

.message.bot-message {
    background-color: var(--bot-message-bg);
    color: var(--text-primary);
    border-bottom-left-radius: 5px;
}

.message.error-message {
    background-color: var(--error-bg);
    color: var(--error-text);
    border: 1px solid rgba(255, 100, 100, 0.5);
}

.message p:not(:last-child) { margin-bottom: 1em; }

.message code {
    background-color: rgba(0, 0, 0, 0.3);
    padding: 2px 6px;
    border-radius: 5px;
    font-family: "SF Mono", "Consolas", monospace;
    font-size: 0.9em;
}

.message pre {
    background-color: #161618;
    padding: 15px;
    border-radius: 8px;
    margin: 12px 0;
    overflow-x: auto;
    border: 1px solid var(--border-color);
}

.message pre code {
    background-color: transparent;
    padding: 0;
    border-radius: 0;
    font-size: 0.9em;
}

/* Thinking Indicator */
@keyframes pulse {
    0%, 100% { opacity: 0.3; transform: scale(0.9); }
    50% { opacity: 1; transform: scale(1); }
}

.thinking-indicator span {
    display: inline-block;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: var(--text-secondary);
    margin: 0 2px;
    animation: pulse 1.4s infinite ease-in-out both;
}

.thinking-indicator span:nth-child(2) { animation-delay: 0.2s; }
.thinking-indicator span:nth-child(3) { animation-delay: 0.4s; }

/* Input Area */
.chat-input-area {
    padding: 15px 20px;
    border-top: 1px solid var(--border-color);
    display: flex;
    align-items: flex-end;
    gap: 10px;
    background-color: var(--header-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

#user-input {
    flex-grow: 1;
    resize: none;
    max-height: 150px;
    line-height: 1.5;
}

#send-button {
    background-color: var(--primary-accent);
    border: none;
    border-radius: 50%;
    width: 44px;
    height: 44px;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.3s;
    flex-shrink: 0;
}

#send-button:hover {
    background-color: var(--primary-accent-hover);
    transform: scale(1.05);
}

#send-button:hover svg {
    transform: rotate(15deg);
}

#send-button svg {
    width: 22px;
    height: 22px;
    color: white;
    transition: transform 0.3s ease-in-out;
}