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

:root {
    --bg-primary: #0d1117;
    --bg-secondary: #161b22;
    --bg-tertiary: #1c2333;
    --text-primary: #e6edf3;
    --text-secondary: #8b949e;
    --accent: #58a6ff;
    --accent-hover: #79b8ff;
    --user-bg: #1f6feb33;
    --bot-bg: #161b22;
    --border: #30363d;
    --input-bg: #0d1117;
    --shadow: 0 2px 12px rgba(0, 0, 0, 0.4);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    height: 100vh;
    overflow: hidden;
}

.app {
    display: flex;
    flex-direction: column;
    height: 100vh;
    max-width: 900px;
    margin: 0 auto;
}

/* Header */
.header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 20px;
    border-bottom: 1px solid var(--border);
    background: var(--bg-secondary);
}

.header h1 {
    font-size: 1.3rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent), #a371f7);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

#model-select {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 6px 10px;
    font-size: 0.85rem;
    cursor: pointer;
}

#new-chat-btn {
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 6px 14px;
    font-size: 0.85rem;
    cursor: pointer;
    transition: all 0.2s;
}

#new-chat-btn:hover {
    color: var(--text-primary);
    border-color: var(--accent);
}

/* Chat */
.chat-container {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    scroll-behavior: smooth;
}

.welcome {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    text-align: center;
    color: var(--text-secondary);
}

.welcome-icon {
    font-size: 3.5rem;
    margin-bottom: 16px;
}

.welcome h2 {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.welcome p {
    font-size: 1rem;
}

/* Messages */
.message {
    display: flex;
    gap: 12px;
    margin-bottom: 20px;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

.message-avatar {
    width: 36px;
    height: 36px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    flex-shrink: 0;
}

.message.user .message-avatar {
    background: #1f6feb;
}

.message.assistant .message-avatar {
    background: linear-gradient(135deg, #58a6ff, #a371f7);
}

.message-body {
    flex: 1;
    max-width: 80%;
}

.message-content {
    line-height: 1.6;
    font-size: 0.95rem;
    padding: 10px 16px;
    border-radius: 12px;
    white-space: pre-wrap;
    word-wrap: break-word;
}

.message.user .message-content {
    background: var(--user-bg);
    border: 1px solid rgba(31, 111, 235, 0.2);
}

.message.assistant .message-content {
    background: var(--bot-bg);
    border: 1px solid var(--border);
}

/* Typing indicator */
.typing-indicator {
    display: inline-flex;
    gap: 4px;
    padding: 4px 0;
}

.typing-indicator span {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--text-secondary);
    animation: bounce 1.4s infinite ease-in-out;
}

.typing-indicator span:nth-child(2) { animation-delay: 0.16s; }
.typing-indicator span:nth-child(3) { animation-delay: 0.32s; }

@keyframes bounce {
    0%, 80%, 100% { transform: scale(0.6); opacity: 0.4; }
    40% { transform: scale(1); opacity: 1; }
}

/* Sources */
.sources {
    margin-top: 10px;
    padding: 8px 12px;
    background: var(--bg-tertiary);
    border-radius: 8px;
    border: 1px solid var(--border);
    font-size: 0.8rem;
}

.sources-title {
    color: var(--text-secondary);
    font-weight: 600;
    margin-bottom: 4px;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.sources a {
    color: var(--accent);
    text-decoration: none;
    display: block;
    padding: 2px 0;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.sources a:hover {
    text-decoration: underline;
    color: var(--accent-hover);
}

/* Web search toggle */
.input-options {
    display: flex;
    align-items: center;
    margin-bottom: 8px;
}

.web-toggle {
    display: flex;
    align-items: center;
    gap: 6px;
    cursor: pointer;
    user-select: none;
    font-size: 0.8rem;
    color: var(--text-secondary);
    transition: color 0.2s;
}

.web-toggle:hover {
    color: var(--text-primary);
}

.web-toggle input {
    display: none;
}

.toggle-slider {
    width: 32px;
    height: 18px;
    background: var(--border);
    border-radius: 9px;
    position: relative;
    transition: background 0.2s;
    flex-shrink: 0;
}

.toggle-slider::after {
    content: "";
    position: absolute;
    top: 2px;
    left: 2px;
    width: 14px;
    height: 14px;
    background: var(--text-secondary);
    border-radius: 50%;
    transition: all 0.2s;
}

.web-toggle input:checked ~ .toggle-slider {
    background: var(--accent);
}

.web-toggle input:checked ~ .toggle-slider::after {
    left: 16px;
    background: white;
}

.web-toggle input:checked ~ .toggle-icon {
    color: var(--accent);
}

.web-toggle input:checked ~ .toggle-label {
    color: var(--accent);
}

.toggle-icon {
    flex-shrink: 0;
    transition: color 0.2s;
}

.toggle-label {
    transition: color 0.2s;
}

/* Searching indicator */
.searching-indicator {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--accent);
    font-size: 0.85rem;
    padding: 4px 0;
}

.searching-indicator svg {
    animation: spin 1s linear infinite;
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* Input */
.input-area {
    padding: 12px 20px 16px;
    border-top: 1px solid var(--border);
    background: var(--bg-secondary);
}

.input-wrapper {
    display: flex;
    align-items: flex-end;
    gap: 8px;
    background: var(--input-bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 8px 12px;
    transition: border-color 0.2s;
}

.input-wrapper:focus-within {
    border-color: var(--accent);
}

#message-input {
    flex: 1;
    background: transparent;
    border: none;
    outline: none;
    color: var(--text-primary);
    font-size: 0.95rem;
    font-family: inherit;
    resize: none;
    max-height: 150px;
    line-height: 1.5;
}

#message-input::placeholder {
    color: var(--text-secondary);
}

#send-btn {
    background: var(--accent);
    border: none;
    border-radius: 8px;
    padding: 8px;
    cursor: pointer;
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.2s;
    flex-shrink: 0;
}

#send-btn:hover {
    background: var(--accent-hover);
}

#send-btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

#stop-btn {
    background: #da3633;
    border: none;
    border-radius: 8px;
    padding: 8px;
    cursor: pointer;
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.2s;
    flex-shrink: 0;
}

#stop-btn:hover {
    background: #f85149;
}

.disclaimer {
    text-align: center;
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-top: 8px;
}

/* Markdown body */
.markdown-body {
    white-space: normal;
}

.markdown-body h1, .markdown-body h2, .markdown-body h3, .markdown-body h4 {
    margin: 12px 0 6px;
    color: var(--text-primary);
    font-weight: 600;
}

.markdown-body h1 { font-size: 1.2rem; }
.markdown-body h2 { font-size: 1.1rem; }
.markdown-body h3 { font-size: 1rem; }

.markdown-body p {
    margin: 6px 0;
}

.markdown-body ul, .markdown-body ol {
    margin: 6px 0;
    padding-left: 20px;
}

.markdown-body li {
    margin: 3px 0;
}

.markdown-body strong {
    color: var(--text-primary);
    font-weight: 600;
}

.markdown-body em {
    color: var(--text-secondary);
}

.markdown-body a {
    color: var(--accent);
    text-decoration: none;
}

.markdown-body a:hover {
    text-decoration: underline;
}

.markdown-body code {
    background: var(--bg-tertiary);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: "SF Mono", "Fira Code", monospace;
    font-size: 0.85em;
}

.markdown-body pre {
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 12px;
    margin: 8px 0;
    overflow-x: auto;
}

.markdown-body pre code {
    background: none;
    padding: 0;
    font-size: 0.85rem;
    line-height: 1.5;
}

.markdown-body blockquote {
    border-left: 3px solid var(--accent);
    padding-left: 12px;
    margin: 8px 0;
    color: var(--text-secondary);
}

.markdown-body table {
    border-collapse: collapse;
    margin: 8px 0;
    width: 100%;
}

.markdown-body th, .markdown-body td {
    border: 1px solid var(--border);
    padding: 6px 10px;
    text-align: left;
    font-size: 0.85rem;
}

.markdown-body th {
    background: var(--bg-tertiary);
    font-weight: 600;
}

.markdown-body hr {
    border: none;
    border-top: 1px solid var(--border);
    margin: 12px 0;
}

/* Scrollbar */
.chat-container::-webkit-scrollbar {
    width: 6px;
}

.chat-container::-webkit-scrollbar-track {
    background: transparent;
}

.chat-container::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 3px;
}

/* Responsive */
@media (max-width: 600px) {
    .header { padding: 10px 14px; }
    .chat-container { padding: 14px; }
    .input-area { padding: 10px 14px 12px; }
    .message-content { max-width: 90%; }
}