@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

:root {
    /* Color Palette - Modern Dark Theme */
    --color-primary: hsl(220, 90%, 56%);
    --color-primary-hover: hsl(220, 90%, 62%);
    --color-success: hsl(142, 71%, 45%);
    --color-success-hover: hsl(142, 71%, 52%);
    --color-danger: hsl(0, 84%, 60%);
    --color-warning: hsl(45, 93%, 58%);

    --color-bg-primary: hsl(220, 18%, 12%);
    --color-bg-secondary: hsl(220, 18%, 16%);
    --color-bg-tertiary: hsl(220, 18%, 20%);
    --color-bg-hover: hsl(220, 18%, 24%);

    --color-text-primary: hsl(0, 0%, 95%);
    --color-text-secondary: hsl(0, 0%, 70%);
    --color-text-muted: hsl(0, 0%, 50%);

    --color-border: hsl(220, 18%, 28%);
    --color-border-light: hsl(220, 18%, 32%);

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(135deg, hsl(220, 20%, 10%) 0%, hsl(220, 18%, 14%) 100%);
    color: var(--color-text-primary);
    line-height: 1.6;
    height: 100vh;
    overflow: hidden;
}

.container {
    max-width: 1600px;
    margin: 0 auto;
    padding: var(--spacing-lg);
    display: flex;
    flex-direction: column;
    height: 100vh;
    overflow: hidden;
}

/* Header */
.header {
    flex-shrink: 0;
    background: var(--color-bg-secondary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg) var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--color-border);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--spacing-lg);
}

.header h1 {
    font-size: 1.75rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--color-primary), hsl(280, 90%, 66%));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.header-controls {
    display: flex;
    gap: var(--spacing-md);
    align-items: center;
}

/* Buttons */
.btn {
    padding: var(--spacing-sm) var(--spacing-lg);
    border: none;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    transition: all var(--transition-base);
    font-family: inherit;
    box-shadow: var(--shadow-sm);
}

.btn:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn:active {
    transform: translateY(0);
}

.btn-primary {
    background: var(--color-primary);
    color: white;
}

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

.btn-success {
    background: var(--color-success);
    color: white;
}

.btn-success:hover {
    background: var(--color-success-hover);
}

.btn-send {
    background: linear-gradient(135deg, var(--color-primary), hsl(280, 90%, 56%));
    color: white;
    padding: var(--spacing-sm) var(--spacing-lg);
}

.btn-send:hover {
    background: linear-gradient(135deg, var(--color-primary-hover), hsl(280, 90%, 62%));
}

/* Status Indicator */
.status-indicator {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-bg-tertiary);
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border);
}

.status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--color-text-muted);
    animation: pulse 2s infinite;
}

.status-indicator.connected .status-dot {
    background: var(--color-success);
}

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

.status-text {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    font-weight: 500;
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

/* Configuration Panel */
.config-panel {
    background: var(--color-bg-secondary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--color-border);
}

.config-content h3 {
    margin-bottom: var(--spacing-lg);
    font-size: 1.25rem;
    color: var(--color-text-primary);
}

.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-group label {
    display: block;
    margin-bottom: var(--spacing-sm);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-text-secondary);
}

.form-group input {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-bg-tertiary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text-primary);
    font-size: 0.875rem;
    font-family: inherit;
    transition: all var(--transition-base);
}

.form-group input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px hsla(220, 90%, 56%, 0.15);
}

/* Main Content Layout */
.main-content {
    display: flex;
    gap: var(--spacing-lg);
    align-items: stretch;
    flex: 1;
    min-height: 0;
}

/* Sidebar */
.sidebar {
    width: 320px;
    min-width: 320px;
    flex-shrink: 0;
    background: var(--color-bg-secondary);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.sidebar-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md) var(--spacing-lg);
    border-bottom: 1px solid var(--color-border);
}

.sidebar-title {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.sidebar-count {
    background: var(--color-primary);
    color: white;
    font-size: 0.75rem;
    font-weight: 600;
    padding: 2px 8px;
    border-radius: 9999px;
    min-width: 24px;
    text-align: center;
}

/* Sidebar Filter */
.sidebar-filter {
    padding: var(--spacing-sm) var(--spacing-md);
    border-bottom: 1px solid var(--color-border);
}

.filter-input {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-bg-tertiary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text-primary);
    font-size: 0.8125rem;
    font-family: inherit;
    transition: all var(--transition-base);
}

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

.filter-input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px hsla(220, 90%, 56%, 0.15);
}

/* Tabs (vertical list inside sidebar) */
.tabs {
    display: flex;
    flex-direction: column;
    gap: 2px;
    padding: var(--spacing-sm);
    overflow-y: auto;
    flex: 1;
}

.tab {
    padding: var(--spacing-md) var(--spacing-md);
    background: transparent;
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-base);
    font-size: 0.8125rem;
    font-weight: 500;
    color: var(--color-text-secondary);
    white-space: nowrap;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--spacing-sm);
    overflow: hidden;
    text-overflow: ellipsis;
}

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

.tab.active {
    background: var(--color-primary);
    color: white;
    border-color: var(--color-primary);
    box-shadow: var(--shadow-sm);
}

.tab.hidden {
    display: none;
}

.tab-badge {
    background: var(--color-bg-tertiary);
    padding: 2px 6px;
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
    flex-shrink: 0;
}

.tab-label {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    min-width: 0;
}

.tab.active .tab-badge {
    background: rgba(255, 255, 255, 0.2);
}

/* Tab Content */
.tab-content-container {
    flex: 1;
    min-width: 0;
    min-height: 0;
    background: var(--color-bg-secondary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--color-border);
    display: flex;
    flex-direction: column;
}

#tabContent {
    flex: 1;
    min-height: 0;
    display: flex;
    flex-direction: column;
}

.conversation-view {
    display: none;
    flex-direction: column;
    flex: 1;
    min-height: 0;
}

.conversation-view.active {
    display: flex;
}

/* Session Info */
.session-info {
    background: var(--color-bg-tertiary);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    border: 1px solid var(--color-border);
}

.session-info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
}

.session-info-item {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.session-info-label {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-muted);
    font-weight: 600;
}

.session-info-value {
    font-size: 0.875rem;
    color: var(--color-text-primary);
    font-weight: 500;
}

.status-badge {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
}

.status-badge.ongoing {
    background: hsla(142, 71%, 45%, 0.2);
    color: var(--color-success);
}

.status-badge.to-be-started {
    background: hsla(45, 93%, 58%, 0.2);
    color: var(--color-warning);
}

.status-badge.closed {
    background: hsla(0, 0%, 50%, 0.2);
    color: var(--color-text-muted);
}

/* Messages */
.messages-container {
    flex: 1;
    min-height: 0;
    overflow-y: auto;
    margin-bottom: var(--spacing-lg);
    padding: var(--spacing-sm);
}

.message {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    animation: slideIn var(--transition-base);
}

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

.message-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    flex-shrink: 0;
    box-shadow: var(--shadow-sm);
}

.message.agent .message-avatar {
    background: linear-gradient(135deg, var(--color-primary), hsl(280, 90%, 56%));
}

.message.counterparty .message-avatar {
    background: linear-gradient(135deg, hsl(142, 71%, 45%), hsl(180, 71%, 45%));
}

.message-content {
    flex: 1;
}

.message-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-xs);
}

.message-sender {
    font-weight: 600;
    font-size: 0.875rem;
    color: var(--color-text-primary);
}

.message-time {
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

.message-text {
    background: var(--color-bg-tertiary);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    line-height: 1.6;
    border: 1px solid var(--color-border);
}

/* Message Input */
.message-input-container {
    display: flex;
    gap: var(--spacing-md);
    align-items: flex-end;
}

.message-input {
    flex: 1;
    background: var(--color-bg-tertiary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    color: var(--color-text-primary);
    font-family: inherit;
    font-size: 0.875rem;
    resize: vertical;
    min-height: 60px;
    transition: all var(--transition-base);
}

.message-input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px hsla(220, 90%, 56%, 0.15);
}

/* Empty State */
.empty-state {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 400px;
}

.empty-state-content {
    text-align: center;
    max-width: 400px;
}

.empty-icon {
    font-size: 4rem;
    display: block;
    margin-bottom: var(--spacing-lg);
}

.empty-state h2 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text-primary);
}

.empty-state p {
    color: var(--color-text-secondary);
    font-size: 0.875rem;
}

/* No Selection State (inside tab-content-container) */
.no-selection-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    flex: 1;
    text-align: center;
    color: var(--color-text-muted);
}

.no-selection-icon {
    font-size: 3.5rem;
    display: block;
    margin-bottom: var(--spacing-lg);
    opacity: 0.6;
}

.no-selection-state h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-sm);
}

.no-selection-state p {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    max-width: 280px;
}

.no-messages {
    text-align: center;
    padding: var(--spacing-xl);
    color: var(--color-text-muted);
    font-size: 0.875rem;
}

/* Loading State */
.loading {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xl);
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--color-border);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

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

::-webkit-scrollbar-track {
    background: var(--color-bg-tertiary);
    border-radius: var(--radius-sm);
}

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

::-webkit-scrollbar-thumb:hover {
    background: var(--color-border-light);
}

/* Responsive Design */
@media (max-width: 900px) {
    .main-content {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        min-width: 0;
        max-height: 260px;
        position: static;
    }
}

@media (max-width: 768px) {
    .container {
        padding: var(--spacing-md);
    }

    .header-content {
        flex-direction: column;
        align-items: flex-start;
    }

    .session-info-grid {
        grid-template-columns: 1fr;
    }

    .message-input-container {
        flex-direction: column;
    }

    .btn-send {
        width: 100%;
    }
}