:root {
    --bg-primary: #212121;
    --bg-secondary: #2b2b2b;
    --bg-tertiary: #323232;
    --bg-hover: #3a3a3a;
    --text-primary: #ececec;
    --text-secondary: #b4b4b4;
    --text-tertiary: #8e8e8e;
    --border-color: #3e3e3e;
    --accent-primary: #0066ff;
    --accent-hover: #0052cc;
    --message-user-bg: #2d2d2d;
    --message-bot-bg: transparent;
    --code-bg: #1e1e1e;
    --success: #00c853;
    --warning: #ffa000;
    --error: #f44336;
}

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

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

/* Chat Container */
.chat-container {
    display: flex;
    height: 100vh;
}

/* Sidebar */
.sidebar {
    width: 260px;
    background: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    flex-shrink: 0;
}

.sidebar-header {
    padding: 16px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.sidebar-header > div:first-child {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 16px;
    font-size: 18px;
    font-weight: 600;
}

.logo-icon {
    font-size: 28px;
}

.back-home-btn {
    padding: 8px;
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s ease;
    text-decoration: none;
}

.back-home-btn:hover {
    background: var(--bg-secondary);
    color: var(--accent-primary);
    border-color: var(--accent-primary);
}

.new-chat-btn {
    width: 100%;
    padding: 10px 14px;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.2s;
}

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

/* Chat History */
.chat-history {
    flex: 1;
    overflow-y: auto;
    padding: 12px 8px;
}

.history-section {
    margin-bottom: 16px;
}

.history-title {
    font-size: 11px;
    font-weight: 600;
    color: var(--text-tertiary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    padding: 8px 12px;
    margin-bottom: 4px;
}

.history-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    border-radius: 8px;
    cursor: pointer;
    transition: background 0.2s;
    color: var(--text-secondary);
}

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

.history-item.active {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.history-text {
    flex: 1;
    font-size: 14px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

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

.profile-btn {
    width: 100%;
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px;
    background: transparent;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    color: var(--text-primary);
    transition: background 0.2s;
}

.profile-btn:hover {
    background: var(--bg-hover);
}

.profile-avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--bg-tertiary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
}

.profile-info {
    flex: 1;
    text-align: left;
}

.profile-name {
    font-size: 14px;
    font-weight: 500;
}

.profile-status {
    font-size: 12px;
    color: var(--text-tertiary);
}

/* Main Chat */
.chat-main {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.chat-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 24px;
    border-bottom: 1px solid var(--border-color);
}

.model-select {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 8px 12px;
    border-radius: 8px;
    font-size: 14px;
    cursor: pointer;
    font-family: inherit;
}

.model-select:focus {
    outline: none;
    border-color: var(--accent-primary);
}

.header-actions {
    display: flex;
    gap: 8px;
}

.icon-btn {
    width: 36px;
    height: 36px;
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
}

.icon-btn:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

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

/* Welcome Screen */
.welcome-screen {
    max-width: 700px;
    margin: 0 auto;
    text-align: center;
    padding-top: 80px;
}

.welcome-logo {
    font-size: 64px;
    margin-bottom: 24px;
}

.welcome-title {
    font-size: 28px;
    font-weight: 600;
    margin-bottom: 40px;
}

.suggestions-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
    margin-top: 32px;
}

.suggestion-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 16px;
    text-align: left;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    gap: 12px;
    align-items: flex-start;
}

.suggestion-card:hover {
    background: var(--bg-hover);
    border-color: var(--accent-primary);
}

.suggestion-icon {
    font-size: 24px;
    flex-shrink: 0;
}

.suggestion-content {
    flex: 1;
}

.suggestion-title {
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 4px;
}

.suggestion-desc {
    font-size: 13px;
    color: var(--text-secondary);
}

/* Messages */
.messages {
    max-width: 800px;
    margin: 0 auto;
}

.message {
    display: flex;
    gap: 16px;
    margin-bottom: 24px;
    animation: fadeIn 0.3s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.message-avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--bg-tertiary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    flex-shrink: 0;
}

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

.message-role {
    font-size: 13px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-secondary);
}

.message-text {
    font-size: 15px;
    line-height: 1.6;
    color: var(--text-primary);
}

.message-text code {
    background: var(--code-bg);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    font-size: 14px;
}

.message-text pre {
    background: var(--code-bg);
    padding: 16px;
    border-radius: 8px;
    overflow-x: auto;
    margin: 12px 0;
    border: 1px solid var(--border-color);
}

.message-text pre code {
    background: none;
    padding: 0;
}

.message-actions {
    display: flex;
    gap: 8px;
    margin-top: 12px;
    opacity: 0;
    transition: opacity 0.2s;
}

.message:hover .message-actions {
    opacity: 1;
}

.message-action-btn {
    background: transparent;
    border: 1px solid var(--border-color);
    padding: 6px 12px;
    border-radius: 6px;
    color: var(--text-secondary);
    font-size: 13px;
    cursor: pointer;
    transition: all 0.2s;
}

.message-action-btn:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

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

.typing-dot {
    width: 8px;
    height: 8px;
    background: var(--text-secondary);
    border-radius: 50%;
    animation: typing 1.4s infinite;
}

.typing-dot:nth-child(2) {
    animation-delay: 0.2s;
}

.typing-dot:nth-child(3) {
    animation-delay: 0.4s;
}

@keyframes typing {
    0%, 60%, 100% {
        opacity: 0.3;
    }
    30% {
        opacity: 1;
    }
}

/* Input Area */
.input-area {
    padding: 16px 24px 24px;
    border-top: 1px solid var(--border-color);
}

.input-wrapper {
    max-width: 800px;
    margin: 0 auto;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 12px;
    display: flex;
    align-items: flex-end;
    gap: 12px;
    transition: border-color 0.2s;
}

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

.input-icon-btn {
    width: 36px;
    height: 36px;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 6px;
    transition: all 0.2s;
    flex-shrink: 0;
}

.input-icon-btn:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

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

.chat-input::placeholder {
    color: var(--text-tertiary);
}

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

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

.send-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.input-footer {
    text-align: center;
    margin-top: 12px;
}

.footer-note {
    font-size: 12px;
    color: var(--text-tertiary);
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}

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

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

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

/* Responsive */
@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        left: -260px;
        transition: left 0.3s;
        z-index: 100;
        height: 100vh;
    }

    .sidebar.active {
        left: 0;
    }

    .suggestions-grid {
        grid-template-columns: 1fr;
    }
}