* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    transition: background-color 0.3s, color 0.3s;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
}

body.night-mode {
    background-color: #1a1a2e;
    color: #e0e0e0;
}

.chat-container {
    max-width: 1000px;
    margin: 0 auto;
    height: 100vh;
    display: flex;
    flex-direction: column;
    background-color: white;
}

body.night-mode .chat-container {
    background-color: #16213e;
}

.header {
    padding: 1rem;
    border-bottom: 1px solid #e5e5e5;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

body.night-mode .header {
    border-bottom-color: #333;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 10px;
}

.night-mode-btn {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.2rem;
    display: flex;
    align-items: center;
    gap: 5px;
}

.night-mode-btn .moon-icon,
.night-mode-btn .sun-icon {
    opacity: 0.5;
}

.night-mode-btn .moon-icon {
    opacity: 1;
}

body.night-mode .night-mode-btn .moon-icon {
    opacity: 0.5;
}

body.night-mode .night-mode-btn .sun-icon {
    opacity: 1;
}

.header h1 {
    font-size: 1.5rem;
    font-weight: 600;
}

body.night-mode .header h1 {
    color: #e0e0e0;
}

.new-chat-btn {
    padding: 0.5rem 1rem;
    background-color: #f0f0f0;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.2s;
}

body.night-mode .new-chat-btn {
    background-color: #0f3460;
    color: #e0e0e0;
}

.new-chat-btn:hover {
    background-color: #e0e0e0;
}

body.night-mode .new-chat-btn:hover {
    background-color: #112b46;
}

.messages {
    flex-grow: 1;
    overflow-y: auto;
    padding: 1rem;
    scroll-behavior: smooth;
}

.message {
    margin-bottom: 1.5rem;
    opacity: 0;
    transform: translateY(20px);
    animation: messageAppear 0.3s ease forwards;
}

@keyframes messageAppear {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.message-content {
    padding: 1rem;
    border-radius: 8px;
    max-width: 80%;
}

.user-message {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
}

.user-message .message-content {
    background-color: #007AFF;
    color: white;
}

body.night-mode .user-message .message-content {
    background-color: #0056b3;
}

.ai-message {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.ai-message .message-content {
    background-color: #f0f0f0;
}

body.night-mode .ai-message .message-content {
    background-color: #112b46;
    color: #e0e0e0;
}

.timestamp {
    font-size: 0.75rem;
    color: #999;
    margin-top: 0.25rem;
}

body.night-mode .timestamp {
    color: #666;
}

.input-container {
    padding: 1rem;
    border-top: 1px solid #e5e5e5;
}

body.night-mode .input-container {
    border-top-color: #333;
}

.input-wrapper {
    display: flex;
    gap: 0.5rem;
    background-color: #f5f5f5;
    border-radius: 8px;
    padding: 0.5rem;
}

body.night-mode .input-wrapper {
    background-color: #0f3460;
}

textarea {
    flex-grow: 1;
    border: none;
    background: none;
    resize: none;
    padding: 0.5rem;
    font-family: inherit;
    font-size: 1rem;
    outline: none;
    color: #333;
}

body.night-mode textarea {
    color: #e0e0e0;
}

.send-button {
    width: 40px;
    height: 40px;
    border: none;
    background-color: #007AFF;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.2s;
}

body.night-mode .send-button {
    background-color: #0056b3;
}

.send-button:hover {
    background-color: #0056b3;
}

.send-button svg {
    width: 20px;
    height: 20px;
    stroke: white;
}

.send-button:disabled {
    background-color: #ccc;
    cursor: not-allowed;
}

body.night-mode .send-button:disabled {
    background-color: #444;
}

.error {
    color: #dc3545;
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

.loading {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: #666;
    font-style: italic;
}

body.night-mode .loading {
    color: #999;
}

.loading::after {
    content: "...";
    animation: loading 1s infinite;
}

@keyframes loading {
    0% { content: "."; }
    33% { content: ".."; }
    66% { content: "..."; }
}

/* Markdown Styles */
.message-content pre {
    background-color: #f8f9fa;
    padding: 1rem;
    border-radius: 4px;
    overflow-x: auto;
}

body.night-mode .message-content pre {
    background-color: #112b46;
    color: #e0e0e0;
}

.message-content code {
    font-family: 'Courier New', Courier, monospace;
    background-color: rgba(0,0,0,0.1);
    padding: 0.2rem 0.4rem;
    border-radius: 3px;
}

body.night-mode .message-content code {
    background-color: rgba(255,255,255,0.1);
}

.message-content p {
    margin-bottom: 1rem;
}

.message-content ul, .message-content ol {
    margin-left: 1.5rem;
    margin-bottom: 1rem;
}