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

:root {
    /* Dark theme (default) */
    --bg-primary: #0f0f0f;
    --bg-secondary: #1a1a1a;
    --bg-tertiary: #252525;
    --bg-hover: #2a2a2a;
    --text-primary: #ffffff;
    --text-secondary: #a0a0a0;
    --text-muted: #666666;
    --accent: #8b5cf6;
    --accent-hover: #7c3aed;
    --accent-light: rgba(139, 92, 246, 0.1);
    --border: #2a2a2a;
    --success: #22c55e;
    --error: #ef4444;
    --user-msg-bg: #8b5cf6;
    --ai-msg-bg: #1f1f1f;
    --shadow: rgba(0, 0, 0, 0.3);
}

[data-theme="light"] {
    --bg-primary: #ffffff;
    --bg-secondary: #f5f5f5;
    --bg-tertiary: #e5e5e5;
    --bg-hover: #ebebeb;
    --text-primary: #1a1a1a;
    --text-secondary: #666666;
    --text-muted: #999999;
    --border: #e0e0e0;
    --ai-msg-bg: #f0f0f0;
    --shadow: rgba(0, 0, 0, 0.1);
}

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

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

/* Sidebar */
.sidebar {
    width: 280px;
    background: var(--bg-secondary);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    transition: transform 0.3s ease;
}

.sidebar.hidden {
    transform: translateX(-100%);
    position: absolute;
    z-index: 100;
    height: 100%;
}

.sidebar-header {
    padding: 20px;
    border-bottom: 1px solid var(--border);
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--accent);
    font-weight: 700;
    font-size: 1.25rem;
}

.new-chat-btn {
    margin: 16px;
    padding: 12px 20px;
    background: var(--accent);
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: all 0.2s ease;
}

.new-chat-btn:hover {
    background: var(--accent-hover);
    transform: translateY(-1px);
}

.chat-history {
    flex: 1;
    overflow-y: auto;
    padding: 8px;
}

.chat-history-item {
    padding: 12px 16px;
    border-radius: 10px;
    cursor: pointer;
    margin-bottom: 4px;
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-secondary);
    transition: all 0.2s ease;
}

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

.chat-history-item.active {
    background: var(--accent-light);
    color: var(--accent);
}

.chat-history-item svg {
    flex-shrink: 0;
}

.chat-history-item span {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.sidebar-footer {
    padding: 16px;
    border-top: 1px solid var(--border);
}

.api-status {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--success);
}

.status-dot.error {
    background: var(--error);
}

/* 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);
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: var(--bg-secondary);
}

.chat-header h1 {
    font-size: 1.25rem;
    font-weight: 600;
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
    padding: 8px;
    border-radius: 8px;
    transition: background 0.2s;
}

.menu-toggle:hover {
    background: var(--bg-hover);
}

.settings-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 8px;
    border-radius: 8px;
    transition: all 0.2s;
}

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

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

.welcome-message {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 40px;
}

.welcome-message.hidden {
    display: none;
}

.welcome-icon {
    color: var(--accent);
    margin-bottom: 24px;
    animation: float 3s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

.welcome-message h2 {
    font-size: 2rem;
    margin-bottom: 12px;
    background: linear-gradient(135deg, var(--accent), #ec4899);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.welcome-message p {
    color: var(--text-secondary);
    font-size: 1.1rem;
    max-width: 400px;
}

.suggestions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 32px;
    justify-content: center;
}

.suggestion-btn {
    padding: 12px 20px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: 12px;
    color: var(--text-primary);
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.2s;
}

.suggestion-btn:hover {
    background: var(--bg-hover);
    border-color: var(--accent);
    transform: translateY(-2px);
}

/* Messages */
.messages {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.message {
    display: flex;
    gap: 12px;
    max-width: 85%;
    animation: slideIn 0.3s ease;
}

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

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

.message-avatar {
    width: 36px;
    height: 36px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    font-size: 1.1rem;
}

.message.user .message-avatar {
    background: var(--accent);
}

.message.ai .message-avatar {
    background: linear-gradient(135deg, #8b5cf6, #ec4899);
}

.message-content {
    padding: 14px 18px;
    border-radius: 16px;
    line-height: 1.6;
}

.message.user .message-content {
    background: var(--user-msg-bg);
    color: white;
    border-bottom-right-radius: 4px;
}

.message.ai .message-content {
    background: var(--ai-msg-bg);
    border: 1px solid var(--border);
    border-bottom-left-radius: 4px;
}

.message-content p {
    margin-bottom: 12px;
}

.message-content p:last-child {
    margin-bottom: 0;
}

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

.message-content code {
    font-family: 'Fira Code', 'Consolas', monospace;
    font-size: 0.9rem;
}

.message-content ul, .message-content ol {
    margin-left: 20px;
    margin-bottom: 12px;
}

.message-content li {
    margin-bottom: 6px;
}

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

.typing-indicator span {
    width: 8px;
    height: 8px;
    background: var(--accent);
    border-radius: 50%;
    animation: typing 1.4s infinite;
}

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

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

@keyframes typing {
    0%, 60%, 100% { transform: translateY(0); opacity: 0.4; }
    30% { transform: translateY(-10px); opacity: 1; }
}

/* Input Container */
.input-container {
    padding: 16px 24px 24px;
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
}

.input-wrapper {
    display: flex;
    align-items: flex-end;
    gap: 12px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 8px 8px 8px 20px;
    transition: border-color 0.2s;
}

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

.input-wrapper textarea {
    flex: 1;
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1rem;
    font-family: inherit;
    resize: none;
    max-height: 150px;
    padding: 8px 0;
    outline: none;
}

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

.send-btn {
    width: 44px;
    height: 44px;
    background: var(--accent);
    border: none;
    border-radius: 12px;
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
    flex-shrink: 0;
}

.send-btn:hover {
    background: var(--accent-hover);
    transform: scale(1.05);
}

.send-btn:disabled {
    background: var(--text-muted);
    cursor: not-allowed;
    transform: none;
}

.disclaimer {
    text-align: center;
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 12px;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    padding: 20px;
    backdrop-filter: blur(4px);
}

.modal.active {
    display: flex;
}

.modal-content {
    background: var(--bg-secondary);
    border-radius: 20px;
    width: 100%;
    max-width: 480px;
    border: 1px solid var(--border);
    animation: modalSlide 0.3s ease;
}

.login-modal {
    max-width: 380px;
}

.login-modal .modal-header h2 {
    text-align: center;
    width: 100%;
}

@keyframes modalSlide {
    from {
        opacity: 0;
        transform: scale(0.95) translateY(-20px);
    }
    to {
        opacity: 1;
        transform: scale(1) translateY(0);
    }
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 24px;
    border-bottom: 1px solid var(--border);
}

.modal-header h2 {
    font-size: 1.25rem;
}

.close-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 8px;
    border-radius: 8px;
    transition: all 0.2s;
}

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

.modal-body {
    padding: 24px;
}

.setting-group {
    margin-bottom: 24px;
}

.setting-group:last-child {
    margin-bottom: 0;
}

.setting-group label {
    display: block;
    font-weight: 500;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.setting-group input,
.setting-group select {
    width: 100%;
    padding: 12px 16px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: 10px;
    color: var(--text-primary);
    font-size: 0.95rem;
    font-family: inherit;
    transition: border-color 0.2s;
}

.setting-group input:focus,
.setting-group select:focus {
    outline: none;
    border-color: var(--accent);
}

.setting-group small {
    display: block;
    margin-top: 8px;
    color: var(--text-muted);
    font-size: 0.8rem;
}

.setting-group small a {
    color: var(--accent);
    text-decoration: none;
}

.setting-group small a:hover {
    text-decoration: underline;
}

.theme-options {
    display: flex;
    gap: 12px;
}

.theme-btn {
    flex: 1;
    padding: 12px;
    background: var(--bg-tertiary);
    border: 2px solid var(--border);
    border-radius: 10px;
    color: var(--text-primary);
    cursor: pointer;
    font-size: 0.95rem;
    transition: all 0.2s;
}

.theme-btn:hover {
    border-color: var(--accent);
}

.theme-btn.active {
    border-color: var(--accent);
    background: var(--accent-light);
}

.modal-footer {
    padding: 16px 24px 24px;
}

.save-btn {
    width: 100%;
    padding: 14px;
    background: var(--accent);
    border: none;
    border-radius: 12px;
    color: white;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.save-btn:hover {
    background: var(--accent-hover);
}

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

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

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

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

/* Mobile Responsive */
@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        left: 0;
        top: 0;
        height: 100%;
        z-index: 100;
        transform: translateX(-100%);
    }

    .sidebar.active {
        transform: translateX(0);
    }

    .menu-toggle {
        display: block;
    }

    .message {
        max-width: 95%;
    }

    .suggestions {
        flex-direction: column;
    }

    .chat-header h1 {
        font-size: 1rem;
    }
}

/* Error message */
.error-message {
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid var(--error);
    color: var(--error);
    padding: 12px 16px;
    border-radius: 10px;
    margin-bottom: 16px;
}