/* ===== CSS Variables ===== */
:root {
    --bg: #0f1117;
    --surface: #1a1d27;
    --border: #2a2d37;
    --text: #e2e8f0;
    --text-dim: #94a3b8;
    --primary: #818cf8;
    --primary-hover: #6366f1;
}

/* ===== Reset & Base ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

/* ===== Sidebar Overlay ===== */
.sidebar-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 998;
}

.sidebar-overlay.visible {
    display: block;
}

/* ===== Sidebar ===== */
.sidebar {
    position: fixed;
    top: 0;
    left: 0;
    width: 260px;
    height: 100%;
    background: var(--surface);
    border-right: 1px solid var(--border);
    z-index: 999;
    display: flex;
    flex-direction: column;
    padding: 12px;
    overflow-y: auto;
}

.new-chat-btn {
    width: 100%;
    padding: 10px 16px;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    margin-bottom: 12px;
    transition: background 0.2s;
}

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

.sidebar-list {
    flex: 1;
    overflow-y: auto;
}

.sidebar-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 12px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 13px;
    color: var(--text-dim);
    transition: background 0.15s, color 0.15s;
    margin-bottom: 2px;
}

.sidebar-item:hover {
    background: var(--border);
    color: var(--text);
}

.sidebar-item.active {
    background: var(--primary);
    color: #fff;
}

.sidebar-item-title {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.sidebar-item-delete {
    background: none;
    border: none;
    color: var(--text-dim);
    cursor: pointer;
    font-size: 16px;
    padding: 0 4px;
    opacity: 0;
    transition: opacity 0.15s;
}

.sidebar-item:hover .sidebar-item-delete {
    opacity: 1;
}

.sidebar-item-delete:hover {
    color: #ef4444;
}

/* ===== Header ===== */
.header {
    position: fixed;
    top: 0;
    left: 260px;
    right: 0;
    height: 56px;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    padding: 0 16px;
    z-index: 100;
    gap: 12px;
}

.menu-btn {
    display: none;
    background: none;
    border: none;
    color: var(--text);
    font-size: 22px;
    cursor: pointer;
    padding: 4px 8px;
}

.logo {
    font-size: 16px;
    font-weight: 700;
    color: var(--text);
    white-space: nowrap;
}

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

.status-badge {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 4px 10px;
    background: var(--bg);
    border-radius: 20px;
    font-size: 12px;
}

.status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: #ef4444;
}

.status-dot.connected {
    background: #22c55e;
}

.status-text {
    color: var(--text-dim);
}

.connect-btn {
    padding: 6px 14px;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
    white-space: nowrap;
}

.connect-btn:hover {
    background: var(--primary-hover);
}

.connect-btn.connected {
    background: #22c55e;
}

.connect-btn.connected:hover {
    background: #ef4444;
}

.meta-connect-btn {
    padding: 6px 14px;
    background: #1877f2;
    color: #fff;
    border: none;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
    white-space: nowrap;
}

.meta-connect-btn:hover {
    background: #1565c0;
}

.meta-connect-btn.connected {
    background: #22c55e;
}

.meta-connect-btn.connected:hover {
    background: #ef4444;
}

/* ===== Chat Container ===== */
.chat-container {
    position: fixed;
    top: 56px;
    left: 260px;
    right: 0;
    bottom: 72px;
    overflow-y: auto;
    padding: 20px;
    display: flex;
    flex-direction: column;
}

/* ===== Welcome Screen ===== */
.welcome-screen {
    max-width: 640px;
    margin: auto;
    text-align: center;
    padding: 20px;
}

.welcome-screen h2 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 24px;
    color: var(--text);
}

.stats-row {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
    margin-bottom: 28px;
}

.stat-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 16px 12px;
}

.stat-value {
    font-size: 28px;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 4px;
}

.stat-label {
    font-size: 12px;
    color: var(--text-dim);
}

.suggestions-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 10px;
}

.suggestion-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 14px 12px;
    font-size: 13px;
    color: var(--text);
    cursor: pointer;
    transition: border-color 0.2s, background 0.2s;
}

.suggestion-card:hover {
    border-color: var(--primary);
    background: rgba(129, 140, 248, 0.08);
}

/* ===== Messages ===== */
.message {
    display: flex;
    gap: 12px;
    margin-bottom: 20px;
    max-width: 800px;
    width: 100%;
    align-self: center;
}

.message-avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    font-weight: 700;
    flex-shrink: 0;
}

.message.user .message-avatar {
    background: var(--primary);
    color: #fff;
}

.message.assistant .message-avatar {
    background: #22c55e;
    color: #fff;
}

.message-content {
    flex: 1;
    line-height: 1.6;
    font-size: 14px;
    color: var(--text);
    overflow-wrap: break-word;
}

.message.user .message-content {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 12px 16px;
}

.message-content p {
    margin-bottom: 8px;
}

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

.message-content a {
    color: var(--primary);
    text-decoration: none;
}

.message-content a:hover {
    text-decoration: underline;
}

.message-content code {
    background: var(--bg);
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 13px;
    font-family: 'SF Mono', 'Fira Code', monospace;
}

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

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

.message-content ul,
.message-content ol {
    padding-left: 20px;
    margin-bottom: 8px;
}

.message-content li {
    margin-bottom: 4px;
}

.message-content strong {
    font-weight: 700;
}

/* ===== Tool Indicator ===== */
.tool-indicator {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 14px;
    background: rgba(129, 140, 248, 0.08);
    border: 1px solid rgba(129, 140, 248, 0.2);
    border-radius: 8px;
    font-size: 12px;
    color: var(--text-dim);
    margin-bottom: 8px;
    max-width: 800px;
    align-self: center;
    width: 100%;
}

.tool-indicator .spinner {
    width: 14px;
    height: 14px;
    border: 2px solid var(--border);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

.tool-indicator.done {
    background: rgba(34, 197, 94, 0.08);
    border-color: rgba(34, 197, 94, 0.2);
}

.tool-indicator .checkmark {
    color: #22c55e;
    font-weight: 700;
    font-size: 14px;
}

.tool-name {
    font-weight: 600;
    color: var(--text);
}

.tool-detail {
    color: var(--text-dim);
    margin-left: 4px;
}

/* ===== Input Area ===== */
.input-area {
    position: fixed;
    bottom: 0;
    left: 260px;
    right: 0;
    padding: 12px 20px;
    background: var(--bg);
    border-top: 1px solid var(--border);
}

.input-wrapper {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    align-items: flex-end;
    gap: 8px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 8px 12px;
    transition: border-color 0.2s;
}

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

.input-wrapper textarea {
    flex: 1;
    background: none;
    border: none;
    color: var(--text);
    font-size: 14px;
    font-family: inherit;
    resize: none;
    outline: none;
    max-height: 120px;
    line-height: 1.5;
    padding: 4px 0;
}

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

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

.send-btn:hover {
    background: var(--primary-hover);
}

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

/* ===== Modal ===== */
.modal-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    z-index: 1000;
    align-items: center;
    justify-content: center;
}

.modal-overlay.visible {
    display: flex;
}

.modal {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 32px;
    max-width: 440px;
    width: 90%;
    position: relative;
}

.modal h3 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text);
}

.modal p {
    font-size: 14px;
    color: var(--text-dim);
    margin-bottom: 16px;
    line-height: 1.5;
}

.auth-input {
    width: 100%;
    padding: 10px 14px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text);
    font-size: 14px;
    font-family: inherit;
    outline: none;
    margin-bottom: 12px;
    transition: border-color 0.2s;
}

.auth-input:focus {
    border-color: var(--primary);
}

.modal-btn {
    width: 100%;
    padding: 10px 20px;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
}

.modal-btn:hover {
    background: var(--primary-hover);
}

.meta-btn {
    background: #1877f2;
}

.meta-btn:hover {
    background: #1565c0;
}

.modal-close {
    position: absolute;
    top: 12px;
    right: 16px;
    background: none;
    border: none;
    color: var(--text-dim);
    font-size: 24px;
    cursor: pointer;
    padding: 4px;
}

.modal-close:hover {
    color: var(--text);
}

/* ===== Mobile: <= 768px ===== */
@media (max-width: 768px) {
    .sidebar {
        margin-left: -260px;
        transition: margin-left 0.25s ease;
    }

    .sidebar.visible {
        margin-left: 0;
    }

    .header {
        left: 0;
    }

    .menu-btn {
        display: block;
    }

    .logo {
        font-size: 14px;
    }

    .header-right {
        gap: 6px;
    }

    .status-badge {
        display: none;
    }

    .connect-btn,
    .meta-connect-btn {
        padding: 5px 10px;
        font-size: 11px;
    }

    .chat-container {
        left: 0;
        padding: 16px 12px;
    }

    .input-area {
        left: 0;
        padding: 10px 12px;
    }

    .input-wrapper textarea {
        font-size: 16px;
    }

    .stats-row {
        grid-template-columns: repeat(3, 1fr);
        gap: 8px;
    }

    .stat-value {
        font-size: 22px;
    }

    .suggestions-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 8px;
    }

    .welcome-screen {
        padding: 12px;
    }

    .welcome-screen h2 {
        font-size: 20px;
    }
}

/* ===== Very Small Screens: <= 400px ===== */
@media (max-width: 400px) {
    .header {
        padding: 0 8px;
        gap: 6px;
    }

    .logo {
        font-size: 12px;
    }

    .connect-btn,
    .meta-connect-btn {
        padding: 4px 8px;
        font-size: 10px;
    }

    .stats-row {
        grid-template-columns: 1fr;
        gap: 8px;
    }

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

    .stat-card {
        padding: 12px 10px;
    }

    .stat-value {
        font-size: 20px;
    }

    .message {
        gap: 8px;
    }

    .message-avatar {
        width: 28px;
        height: 28px;
        font-size: 12px;
    }

    .message-content {
        font-size: 13px;
    }
}