/* Modern CSS Reset and Base Styles */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Color System */
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --header-gradient: linear-gradient(135deg, #4f46e5 0%, #7c3aed 100%);
    --surface: #ffffff;
    --surface-alt: #f8fafc;
    --surface-dark: #1e293b;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --border: #e2e8f0;
    --border-focus: #4f46e5;
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --shadow-lg: 0 25px 50px -12px rgba(0, 0, 0, 0.25);

    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', Monaco, 'Cascadia Code', monospace;

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;

    /* Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}

body {
    font-family: var(--font-sans);
    background: var(--primary-gradient);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
}

/* Animated Background Elements */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background:
        radial-gradient(circle at 20% 50%, rgba(79, 70, 229, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(124, 58, 237, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 40% 80%, rgba(16, 185, 129, 0.1) 0%, transparent 50%);
    z-index: -1;
    animation: backgroundShift 20s ease-in-out infinite;
}

@keyframes backgroundShift {
    0%, 100% { opacity: 1; transform: translateY(0px) rotate(0deg); }
    50% { opacity: 0.8; transform: translateY(-10px) rotate(1deg); }
}

/* Main App Container */
.app {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    max-width: 1400px;
    margin: 0 auto;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(20px);
    box-shadow: var(--shadow-lg);
    border-radius: var(--radius-xl);
    overflow: hidden;
    position: relative;
}

@media (max-width: 768px) {
    .app {
        margin: 0;
        border-radius: 0;
        min-height: 100vh;
    }
}

/* Header Styles */
.header {
    background: var(--header-gradient);
    color: white;
    padding: var(--space-2xl) var(--space-xl) var(--space-lg);
    position: relative;
    overflow: hidden;
}

.header::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
    animation: headerShimmer 3s ease-in-out infinite;
}

@keyframes headerShimmer {
    0% { left: -100%; }
    100% { left: 100%; }
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--space-md);
    position: relative;
    z-index: 2;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.logo-icon {
    font-size: 2rem;
    filter: drop-shadow(0 0 10px rgba(255, 255, 255, 0.3));
    animation: logoFloat 4s ease-in-out infinite;
}

@keyframes logoFloat {
    0%, 100% { transform: translateY(0px) rotate(0deg); }
    50% { transform: translateY(-3px) rotate(5deg); }
}

.logo h1 {
    font-size: clamp(1.5rem, 4vw, 2rem);
    font-weight: 700;
    margin: 0;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.powered-by {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 0.9rem;
    opacity: 0.9;
    font-weight: 500;
}

.powered-by img {
    height: 20px;
    filter: brightness(0) invert(1);
}

.subtitle {
    font-size: clamp(1rem, 2.5vw, 1.125rem);
    opacity: 0.95;
    font-weight: 400;
    position: relative;
    z-index: 2;
}

/* Welcome Section */
.welcome-section {
    padding: var(--space-2xl);
    animation: fadeInUp 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.welcome-content h2 {
    color: var(--text-primary);
    margin-bottom: var(--space-lg);
    font-size: clamp(1.25rem, 3vw, 1.5rem);
    font-weight: 600;
}

.welcome-content p {
    color: var(--text-secondary);
    margin-bottom: var(--space-xl);
    line-height: 1.7;
    font-size: 1.125rem;
}

/* Features Grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-lg);
    margin-bottom: var(--space-2xl);
}

.feature-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    text-align: center;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
    cursor: pointer;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, transparent, rgba(79, 70, 229, 0.03), transparent);
    transform: translateX(-100%);
    transition: transform var(--transition-slow);
}

.feature-card:hover::before {
    transform: translateX(0);
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow);
    border-color: var(--border-focus);
}

.feature-icon {
    font-size: 2.5rem;
    display: block;
    margin-bottom: var(--space-md);
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.1));
}

.feature-card h3 {
    color: var(--text-primary);
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: var(--space-sm);
}

.feature-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.5;
    margin: 0;
}

/* Example Prompts */
.example-prompts {
    background: var(--surface-alt);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
}

.example-prompts p {
    margin-bottom: var(--space-lg);
    color: var(--text-primary);
    font-weight: 600;
    font-size: 1.125rem;
}

.prompt-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
}

.prompt-btn {
    background: var(--header-gradient);
    color: white;
    border: none;
    border-radius: var(--radius-full);
    padding: var(--space-sm) var(--space-lg);
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    font-family: inherit;
    white-space: nowrap;
}

.prompt-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(79, 70, 229, 0.4);
}

.prompt-btn:active {
    transform: translateY(-1px);
}

/* Chat Container */
.main-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-height: 0;
}

.chat-wrapper {
    flex: 1;
    overflow-y: auto;
    padding: var(--space-xl);
    scroll-behavior: smooth;
}

.chat-wrapper::-webkit-scrollbar {
    width: 6px;
}

.chat-wrapper::-webkit-scrollbar-track {
    background: var(--surface-alt);
    border-radius: var(--radius-sm);
}

.chat-wrapper::-webkit-scrollbar-thumb {
    background: var(--text-muted);
    border-radius: var(--radius-sm);
}

.chat-wrapper::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}

/* Messages */
.messages {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
    max-width: 100%;
}

.message {
    display: flex;
    gap: var(--space-md);
    animation: messageSlideIn 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    max-width: 100%;
}

@keyframes messageSlideIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

.message-avatar {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    flex-shrink: 0;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    position: relative;
    overflow: hidden;
}

.message.user .message-avatar {
    background: linear-gradient(135deg, var(--success) 0%, #34d399 100%);
}

.message.assistant .message-avatar {
    background: var(--header-gradient);
}

.message-content {
    max-width: min(75%, 600px);
    background: var(--surface);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    position: relative;
    word-wrap: break-word;
    overflow-wrap: break-word;
}

.message.user .message-content {
    background: var(--header-gradient);
    color: white;
    border-color: transparent;
}

.message-content::before {
    content: '';
    position: absolute;
    top: 16px;
    width: 0;
    height: 0;
    border: 8px solid transparent;
}

.message.assistant .message-content::before {
    left: -16px;
    border-right-color: var(--surface);
}

.message.user .message-content::before {
    right: -16px;
    border-left-color: #4f46e5;
}

.message-text {
    line-height: 1.6;
    margin: 0;
    font-size: 1rem;
}

.message-text strong {
    font-weight: 600;
}

.message-text em {
    font-style: italic;
}

.highlight-emoji {
    font-size: 1.1em;
    margin: 0 2px;
}

.message-meta {
    font-size: 0.8rem;
    opacity: 0.8;
    margin-top: var(--space-sm);
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 500;
}

/* Typing Indicator */
.typing-indicator {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-lg);
    color: var(--text-secondary);
    font-style: italic;
    animation: fadeIn var(--transition-normal);
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.typing-dots {
    display: flex;
    gap: 4px;
}

.typing-dots span {
    width: 8px;
    height: 8px;
    background: var(--text-muted);
    border-radius: var(--radius-full);
    animation: typingBounce 1.4s infinite;
}

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

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

@keyframes typingBounce {
    0%, 60%, 100% {
        transform: translateY(0);
    }
    30% {
        transform: translateY(-12px);
    }
}

/* Input Section */
.input-section {
    background: var(--surface);
    border-top: 1px solid var(--border);
    padding: var(--space-xl);
    position: relative;
}

.input-container {
    display: flex;
    gap: var(--space-sm);
    align-items: flex-end;
    background: var(--surface-alt);
    border: 2px solid var(--border);
    border-radius: var(--radius-xl);
    padding: var(--space-md) var(--space-lg);
    transition: all var(--transition-fast);
    max-width: 100%;
}

.input-container:focus-within {
    border-color: var(--border-focus);
    background: var(--surface);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

#messageInput {
    flex: 1;
    border: none;
    background: transparent;
    font-family: inherit;
    font-size: 1rem;
    resize: none;
    outline: none;
    min-height: 24px;
    max-height: 120px;
    line-height: 1.5;
    color: var(--text-primary);
    min-width: 0;
}

#messageInput::placeholder {
    color: var(--text-muted);
}

.send-btn {
    background: var(--header-gradient);
    color: white;
    border: none;
    border-radius: var(--radius-full);
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-fast);
    flex-shrink: 0;
    box-shadow: 0 2px 8px rgba(79, 70, 229, 0.3);
}

.send-btn:hover:not(:disabled) {
    transform: scale(1.05);
    box-shadow: 0 4px 16px rgba(79, 70, 229, 0.4);
}

.send-btn:active:not(:disabled) {
    transform: scale(0.98);
}

.send-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
    box-shadow: 0 2px 8px rgba(79, 70, 229, 0.2);
}

/* Input Footer */
.input-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: var(--space-lg);
    font-size: 0.875rem;
    color: var(--text-secondary);
    flex-wrap: wrap;
    gap: var(--space-sm);
}

.user-info {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.user-id code {
    background: var(--surface-alt);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
    font-family: var(--font-mono);
    font-size: 0.8rem;
    border: 1px solid var(--border);
}

.clear-btn {
    background: var(--error);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    padding: var(--space-xs) var(--space-md);
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.clear-btn:hover {
    background: #dc2626;
    transform: translateY(-1px);
}

/* Status Bar */
.status-bar {
    background: var(--surface-dark);
    color: #d1d5db;
    padding: var(--space-sm) var(--space-xl);
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.8rem;
    font-weight: 500;
}

.status-item {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.status-indicator {
    width: 8px;
    height: 8px;
    border-radius: var(--radius-full);
    background: var(--text-muted);
}

.status-indicator.connected {
    background: var(--success);
    box-shadow: 0 0 8px rgba(16, 185, 129, 0.6);
    animation: statusPulse 2s infinite;
}

@keyframes statusPulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.6; }
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    animation: fadeIn var(--transition-normal);
}

.loading-content {
    background: var(--surface);
    border-radius: var(--radius-lg);
    padding: var(--space-2xl);
    text-align: center;
    box-shadow: var(--shadow-lg);
    max-width: 90vw;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border);
    border-top: 3px solid var(--border-focus);
    border-radius: var(--radius-full);
    animation: spin 1s linear infinite;
    margin: 0 auto var(--space-lg);
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Responsive Design */
@media (max-width: 1024px) {
    .app {
        max-width: 100%;
        margin: var(--space-md);
        border-radius: var(--radius-lg);
    }
}

@media (max-width: 768px) {
    .app {
        margin: 0;
        border-radius: 0;
        min-height: 100vh;
    }

    .header {
        padding: var(--space-xl) var(--space-lg) var(--space-lg);
    }

    .header-content {
        flex-direction: column;
        gap: var(--space-sm);
        text-align: center;
    }

    .welcome-section {
        padding: var(--space-xl) var(--space-lg);
    }

    .chat-wrapper {
        padding: var(--space-lg);
    }

    .features-grid {
        grid-template-columns: 1fr;
        gap: var(--space-lg);
    }

    .message-content {
        max-width: 90%;
    }

    .input-section {
        padding: var(--space-lg);
    }

    .input-footer {
        flex-direction: column;
        align-items: flex-start;
    }

    .status-bar {
        padding: var(--space-sm) var(--space-lg);
        flex-direction: column;
        gap: var(--space-xs);
        text-align: center;
    }

    .prompt-buttons {
        flex-direction: column;
    }

    .prompt-btn {
        width: 100%;
        text-align: center;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .message-content {
        max-width: 85%;
        padding: var(--space-md);
    }

    .message-avatar {
        width: 36px;
        height: 36px;
        font-size: 1.1rem;
    }

    .input-container {
        padding: var(--space-md);
    }

    .send-btn {
        width: 40px;
        height: 40px;
    }
}

/* Accessibility Improvements */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

@media (prefers-color-scheme: dark) {
    :root {
        --surface: #1e293b;
        --surface-alt: #334155;
        --surface-dark: #0f172a;
        --text-primary: #f1f5f9;
        --text-secondary: #cbd5e1;
        --text-muted: #94a3b8;
        --border: #475569;
        --border-focus: #6366f1;
    }

    body {
        background: linear-gradient(135deg, #1e293b 0%, #334155 100%);
    }

    .app {
        background: rgba(30, 41, 59, 0.98);
    }

    .message-content {
        background: var(--surface-alt);
        border-color: var(--border);
    }

    .message.assistant .message-content::before {
        border-right-color: var(--surface-alt);
    }
}

/* Focus styles for better accessibility */
*:focus-visible {
    outline: 2px solid var(--border-focus);
    outline-offset: 2px;
}

/* Selection styling */
::selection {
    background: rgba(79, 70, 229, 0.2);
}

/* Smooth transitions for interactive elements */
.prompt-btn,
.feature-card,
.message,
.send-btn,
.clear-btn {
    will-change: transform;
}

/* Performance optimizations */
.header::before,
body::before {
    will-change: transform;
}

.typing-dots span {
    will-change: transform;
}