:root {
    --bg-primary: #212121;
    --bg-secondary: #171717;
    --bg-tertiary: #2f2f2f;
    --bg-hover: #3a3a3a;
    --text-primary: #ececec;
    --text-secondary: #9b9b9b;
    --accent-color: #10a37f;
    --accent-hover: #1a7f64;
    --border-color: #3a3a3a;
    --sidebar-width: 260px;
}

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

html, body {
    height: 100%;
    font-family: 'Segoe UI', 'Helvetica Neue', sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
}

.app-container {
    height: 100vh;
    width: 100%;
}

.chat-container {
    display: flex;
    height: 100%;
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background-color: var(--bg-secondary);
    display: flex;
    flex-direction: column;
    border-right: 1px solid var(--border-color);
}

.sidebar-header {
    padding: 12px;
}

.new-chat-btn {
    width: 100%;
    padding: 12px 16px;
    background-color: transparent;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 14px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 12px;
    transition: background-color 0.2s;
}

.new-chat-btn:hover {
    background-color: var(--bg-hover);
}

.new-chat-btn svg {
    width: 18px;
    height: 18px;
}

.sidebar-content {
    flex: 1;
    overflow-y: auto;
    padding: 8px;
}

.nav-item {
    padding: 12px 16px;
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 14px;
    color: var(--text-primary);
    transition: background-color 0.2s;
}

.nav-item:hover {
    background-color: var(--bg-hover);
}

.nav-item.active {
    background-color: var(--bg-tertiary);
}

.nav-item svg {
    width: 18px;
    height: 18px;
    flex-shrink: 0;
}

.sidebar-footer {
    padding: 12px;
    border-top: 1px solid var(--border-color);
}

.user-info {
    padding: 12px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 14px;
    color: var(--text-primary);
}

.user-info.not-logged-in {
    color: var(--text-secondary);
}

.user-info svg {
    width: 18px;
    height: 18px;
}

/* Main Chat Area */
.chat-main {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
}

.chat-header {
    padding: 16px 24px;
    border-bottom: 1px solid var(--border-color);
    background-color: var(--bg-primary);
}

.chat-header h1 {
    font-size: 18px;
    font-weight: 600;
}

/* Messages Container */
.messages-container {
    flex: 1;
    overflow-y: auto;
    padding: 24px 0;
}

/* Welcome Message */
.welcome-message {
    max-width: 600px;
    margin: 60px auto;
    text-align: center;
    padding: 0 24px;
}

.welcome-icon {
    font-size: 48px;
    margin-bottom: 16px;
}

.welcome-message h2 {
    font-size: 28px;
    font-weight: 600;
    margin-bottom: 12px;
}

.welcome-message p {
    color: var(--text-secondary);
    margin-bottom: 32px;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
}

.feature-card {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 16px;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    transition: background-color 0.2s, border-color 0.2s;
}

.feature-card:hover {
    background-color: var(--bg-hover);
    border-color: var(--text-secondary);
}

.feature-icon {
    font-size: 24px;
}

.feature-card span:last-child {
    font-size: 13px;
    color: var(--text-secondary);
}

/* Messages */
.message {
    display: flex;
    gap: 16px;
    padding: 24px;
    max-width: 900px;
    margin: 0 auto;
}

.message-avatar {
    flex-shrink: 0;
}

.avatar {
    width: 36px;
    height: 36px;
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    font-weight: 600;
}

.user-avatar {
    background-color: #5436DA;
    color: white;
}

.assistant-avatar {
    background-color: var(--accent-color);
    font-size: 18px;
}

.message-content {
    flex: 1;
    min-width: 0;
}

.message-text {
    line-height: 1.7;
    font-size: 15px;
}

.message-time {
    font-size: 11px;
    color: var(--text-secondary);
    margin-top: 8px;
}

/* Function Calls */
.function-calls {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 12px;
}

.function-call {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 4px 10px;
    background-color: var(--bg-tertiary);
    border-radius: 16px;
    font-size: 12px;
    color: var(--text-secondary);
}

.function-icon {
    font-size: 12px;
}

.function-name {
    font-family: 'Monaco', 'Menlo', monospace;
}

/* Typing Indicator */
.typing-indicator {
    display: flex;
    gap: 4px;
    padding: 8px 0;
}

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

.typing-indicator span:nth-child(1) {
    animation-delay: -0.32s;
}

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

@keyframes typing {
    0%, 80%, 100% {
        transform: scale(0.6);
        opacity: 0.5;
    }
    40% {
        transform: scale(1);
        opacity: 1;
    }
}

/* Input Area */
.input-container {
    padding: 16px 24px 24px;
    background-color: var(--bg-primary);
}

.input-wrapper {
    max-width: 850px;
    margin: 0 auto;
    display: flex;
    align-items: flex-end;
    gap: 12px;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 12px 16px;
    transition: border-color 0.2s;
}

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

.input-wrapper textarea {
    flex: 1;
    background: transparent;
    border: none;
    outline: none;
    color: var(--text-primary);
    font-size: 15px;
    font-family: inherit;
    resize: none;
    max-height: 200px;
    line-height: 1.5;
}

.input-wrapper textarea::placeholder {
    color: var(--text-secondary);
}

.input-wrapper textarea:disabled {
    opacity: 0.6;
}

.send-btn {
    width: 36px;
    height: 36px;
    border-radius: 8px;
    border: none;
    background-color: var(--accent-color);
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.2s;
    flex-shrink: 0;
}

.send-btn:hover:not(:disabled) {
    background-color: var(--accent-hover);
}

.send-btn:disabled {
    background-color: var(--bg-hover);
    cursor: not-allowed;
}

.send-btn svg {
    width: 18px;
    height: 18px;
}

.input-hint {
    text-align: center;
    font-size: 11px;
    color: var(--text-secondary);
    margin-top: 8px;
}

/* Spinner */
.spinner {
    width: 18px;
    height: 18px;
    border: 2px solid transparent;
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

/* Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background-color: var(--border-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background-color: var(--text-secondary);
}

/* Responsive */
@media (max-width: 768px) {
    .sidebar {
        display: none;
    }
    
    .feature-grid {
        grid-template-columns: 1fr;
    }
    
    .message {
        padding: 16px;
    }
}