:root {
    --bg-primary: #0d1117;
    --bg-secondary: #161b22;
    --bg-tertiary: #21262d;
    --border-color: #30363d;
    --text-primary: #f0f6fc;
    --text-secondary: #8b949e;
    --accent-color: #58a6ff;
    --accent-hover: #388bfd;
    --accent-green: #238636;
    --accent-purple: #8957e5;
    --accent-orange: #d29922;
    --accent-red: #da3633;
    --sidebar-width: 280px;
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    height: 100vh;
    overflow: hidden;
}

/* Modal Overlay */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.85);
    backdrop-filter: blur(8px);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
}
.modal-overlay.hidden {
    display: none;
}

.login-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    width: 400px;
    padding: 35px;
    text-align: center;
    box-shadow: 0 10px 40px rgba(0,0,0,0.6);
}

.brand-logo {
    font-size: 3rem;
    color: var(--accent-color);
    margin-bottom: 15px;
}
.pulse-icon {
    animation: pulse 2.5s infinite;
}
@keyframes pulse {
    0% { transform: scale(1); filter: drop-shadow(0 0 5px rgba(88,166,255,0.4)); }
    50% { transform: scale(1.08); filter: drop-shadow(0 0 15px rgba(88,166,255,0.8)); }
    100% { transform: scale(1); filter: drop-shadow(0 0 5px rgba(88,166,255,0.4)); }
}

.login-card h2 {
    font-size: 1.6rem;
    margin-bottom: 6px;
    letter-spacing: 1px;
}
.subtitle {
    font-size: 0.88rem;
    color: var(--text-secondary);
    margin-bottom: 25px;
}

.input-group {
    text-align: left;
    margin-bottom: 18px;
}
.input-group label {
    display: block;
    font-size: 0.82rem;
    color: var(--text-secondary);
    margin-bottom: 6px;
}
.input-group input {
    width: 100%;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 10px 14px;
    color: var(--text-primary);
    font-size: 0.95rem;
    outline: none;
    transition: border 0.2s;
}
.input-group input:focus {
    border-color: var(--accent-color);
}

.btn-primary {
    width: 100%;
    background: var(--accent-color);
    color: #fff;
    border: none;
    border-radius: var(--radius-sm);
    padding: 12px;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
}
.btn-primary:hover {
    background: var(--accent-hover);
}

.login-footer {
    margin-top: 25px;
    font-size: 0.78rem;
    color: var(--text-secondary);
}

.error-badge {
    background: rgba(218, 54, 51, 0.2);
    border: 1px solid var(--accent-red);
    color: #ff7b72;
    padding: 8px;
    border-radius: var(--radius-sm);
    margin-bottom: 15px;
    font-size: 0.85rem;
}
.error-badge.hidden { display: none; }

/* App Layout */
.app-layout {
    display: flex;
    height: 100vh;
}

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

.sidebar-header {
    padding: 18px 16px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
}
.sidebar-brand {
    font-size: 1.1rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--accent-color);
}
.btn-icon {
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
}
.btn-icon:hover {
    background: var(--bg-tertiary);
}

.brain-selector-box {
    padding: 12px 16px;
    border-bottom: 1px solid var(--border-color);
}
.brain-selector-box label {
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-bottom: 6px;
    display: block;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}
.brain-selector-box select {
    width: 100%;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    padding: 8px 10px;
    font-size: 0.85rem;
    outline: none;
}

.conversations-history {
    flex: 1;
    overflow-y: auto;
    padding: 10px;
}
.conv-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 12px;
    border-radius: var(--radius-sm);
    font-size: 0.88rem;
    color: var(--text-secondary);
    cursor: pointer;
    margin-bottom: 4px;
    transition: background 0.15s, color 0.15s;
}
.conv-item:hover, .conv-item.active {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}
.conv-item .conv-title {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    max-width: 180px;
}
.conv-item .btn-del {
    opacity: 0;
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
}
.conv-item:hover .btn-del {
    opacity: 1;
}
.conv-item .btn-del:hover {
    color: var(--accent-red);
}

.sidebar-nav {
    display: flex;
    flex-direction: column;
    padding: 10px;
    border-top: 1px solid var(--border-color);
}
.nav-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 14px;
    background: transparent;
    border: none;
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    font-size: 0.88rem;
    font-weight: 500;
    cursor: pointer;
    text-align: left;
    transition: background 0.15s, color 0.15s;
}
.nav-item:hover, .nav-item.active {
    background: var(--bg-tertiary);
    color: var(--accent-color);
}

.sidebar-footer {
    padding: 14px 16px;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.user-info {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.88rem;
}

/* Main Content Views */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.view-tab {
    display: none;
    flex: 1;
    flex-direction: column;
    height: 100%;
    overflow: hidden;
}
.view-tab.active {
    display: flex;
}

/* Chat Header */
.chat-header {
    padding: 14px 24px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--bg-secondary);
}
.active-conv-title {
    font-size: 1rem;
    font-weight: 600;
}
.header-badges {
    display: flex;
    gap: 10px;
}
.badge {
    padding: 4px 10px;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}
.badge-success { background: rgba(35, 134, 54, 0.2); color: #3fb950; border: 1px solid var(--accent-green); }
.badge-info { background: rgba(88, 166, 255, 0.2); color: #58a6ff; border: 1px solid var(--accent-color); }
.badge-purple { background: rgba(137, 87, 229, 0.2); color: #a371f7; border: 1px solid var(--accent-purple); }

/* Chat Messages */
.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.message-row {
    display: flex;
    gap: 16px;
    max-width: 900px;
    width: 100%;
    margin: 0 auto;
}
.message-row.user {
    justify-content: flex-end;
}
.avatar {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    flex-shrink: 0;
}
.avatar.user-avatar { background: var(--accent-purple); color: #fff; }
.avatar.bot-avatar { background: var(--accent-color); color: #fff; }

.message-bubble {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 14px 18px;
    font-size: 0.95rem;
    line-height: 1.6;
    max-width: 820px;
}
.message-row.user .message-bubble {
    background: var(--bg-tertiary);
    border-color: #3b434d;
}

.message-meta {
    margin-top: 8px;
    display: flex;
    gap: 12px;
    font-size: 0.75rem;
    color: var(--text-secondary);
    border-top: 1px solid rgba(255,255,255,0.08);
    padding-top: 6px;
}

.message-bubble pre {
    background: #090d13;
    padding: 12px;
    border-radius: var(--radius-sm);
    overflow-x: auto;
    margin: 10px 0;
    position: relative;
}
.message-bubble code {
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.88rem;
}

/* Chat Input Container */
.chat-input-container {
    padding: 16px 24px 20px 24px;
    background: var(--bg-primary);
}
.input-wrapper {
    max-width: 900px;
    margin: 0 auto;
    position: relative;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    padding: 8px 12px;
}
.input-wrapper:focus-within {
    border-color: var(--accent-color);
}
.input-wrapper textarea {
    flex: 1;
    background: transparent;
    border: none;
    color: var(--text-primary);
    font-size: 0.95rem;
    resize: none;
    outline: none;
    max-height: 150px;
    padding: 6px;
}
.btn-send {
    background: var(--accent-color);
    color: #fff;
    border: none;
    border-radius: 50%;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: opacity 0.2s;
}
.btn-send:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}
.input-footer {
    text-align: center;
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-top: 8px;
}

/* Welcome Hero */
.welcome-hero {
    max-width: 800px;
    margin: 40px auto;
    text-align: center;
}
.hero-icon {
    font-size: 4rem;
    color: var(--accent-color);
    margin-bottom: 16px;
}
.welcome-hero h2 {
    font-size: 1.8rem;
    margin-bottom: 10px;
}
.welcome-hero p {
    color: var(--text-secondary);
    margin-bottom: 30px;
}
.hero-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}
.hero-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 20px;
    text-align: left;
    cursor: pointer;
    transition: transform 0.2s, border 0.2s;
}
.hero-card:hover {
    transform: translateY(-3px);
    border-color: var(--accent-color);
}
.hero-card i {
    font-size: 1.4rem;
    color: var(--accent-color);
    margin-bottom: 10px;
}
.hero-card h4 {
    margin-bottom: 6px;
    font-size: 0.95rem;
}
.hero-card p {
    font-size: 0.8rem;
    margin-bottom: 0;
}

/* Tabs Common Header & Layouts */
.tab-header {
    padding: 24px;
    border-bottom: 1px solid var(--border-color);
    background: var(--bg-secondary);
}
.tab-header h2 {
    font-size: 1.4rem;
    margin-bottom: 4px;
}
.tab-header p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Agents Grid */
.agents-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 16px;
    padding: 24px;
    overflow-y: auto;
}
.agent-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 20px;
}
.agent-card-header {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 10px;
    color: var(--accent-color);
    font-weight: 600;
}
.agent-card p {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* System Metrics */
.metrics-dashboard {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
    padding: 24px;
}
.metric-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 20px;
}
.metric-header {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    gap: 8px;
}
.metric-value {
    font-size: 1.6rem;
    font-weight: 700;
    margin-bottom: 6px;
}
.metric-value.highlight {
    color: #3fb950;
}
.metric-label {
    font-size: 0.78rem;
    color: var(--text-secondary);
}

.system-status-box {
    margin: 0 24px 24px 24px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 20px;
}
.status-row {
    display: flex;
    justify-content: space-between;
    padding: 10px 0;
    border-bottom: 1px solid rgba(255,255,255,0.05);
    font-size: 0.9rem;
}

/* Upload zone */
.upload-zone {
    margin: 24px;
    border: 2px dashed var(--border-color);
    border-radius: var(--radius-md);
    padding: 40px;
    text-align: center;
    background: var(--bg-secondary);
    cursor: pointer;
}
.upload-zone i {
    font-size: 2.5rem;
    color: var(--accent-color);
    margin-bottom: 12px;
}

/* Responsive adjustments */
@media (max-width: 900px) {
    .sidebar { width: 70px; }
    .sidebar-brand span, .brain-selector-box label, .brain-selector-box select, .nav-item span, .user-info span, .conv-title { display: none; }
    .metrics-dashboard { grid-template-columns: 1fr 1fr; }
    .hero-cards { grid-template-columns: 1fr; }
}

/* Messages List Container */
.messages-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
    width: 100%;
}

/* Typing Indicator */
.typing-indicator {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 4px 0;
    color: var(--text-secondary);
    font-size: 0.85rem;
}
.typing-indicator span {
    width: 6px;
    height: 6px;
    background: var(--accent-color);
    border-radius: 50%;
    display: inline-block;
    animation: typingBounce 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; }
.typing-indicator span:nth-child(3) { animation-delay: 0s; }

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

/* Empty Conversations State */
.empty-conversations {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 30px 10px;
    color: var(--text-secondary);
    font-size: 0.82rem;
    text-align: center;
    gap: 8px;
}
.empty-conversations i {
    font-size: 1.5rem;
    opacity: 0.5;
}

/* Chat Error Box with Retry */
.chat-error-box {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    color: var(--accent-red);
    background: rgba(248, 81, 73, 0.1);
    border: 1px solid rgba(248, 81, 73, 0.3);
    border-radius: var(--radius-sm);
    padding: 8px 12px;
    font-size: 0.88rem;
}
.btn-retry {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 4px 10px;
    font-size: 0.78rem;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}
.btn-retry:hover {
    background: var(--accent-color);
    color: white;
}