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

:root {
    /* Light theme (default) */
    --primary-bg: #f4f4fa;
    --secondary-bg: #f8f8fc;
    --sidebar-bg: #f8f9fa;
    --text-primary: #1a1a1a;
    --text-secondary: #6b7280;
    --text-muted: #9ca3af;
    --border-color: #e5e7eb;
    --border-light: #f3f4f6;
    --accent-color: #764ba2;
    --accent-hover: #2563eb;
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --border-radius: 12px;
    --border-radius-sm: 8px;
    
    /* Theme transition */
    transition: background-color 0.3s ease, color 0.3s ease;
}

[data-theme="dark"] {
    /* Dark theme */
    --primary-bg: #0f0f0f;
    --secondary-bg: #1a1a1a;
    --sidebar-bg: #111111;
    --text-primary: #ffffff;
    --text-secondary: #a1a1aa;
    --text-muted: #71717a;
    --border-color: #27272a;
    --border-light: #1f1f1f;
    --accent-color: #764ba2;
    --accent-hover: #60a5fa;
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -2px rgba(0, 0, 0, 0.3);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
    background: var(--primary-bg);
    color: var(--text-primary);
    height: 100vh;
    overflow: hidden;
    font-size: 14px;
    line-height: 1.5;
    transition: background-color 0.3s cubic-bezier(0.4, 0, 0.2, 1), color 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 20% 30%, rgba(99, 102, 241, 0.4) 0%, transparent 60%),
        radial-gradient(circle at 80% 70%, rgba(236, 72, 153, 0.4) 0%, transparent 60%),
        radial-gradient(circle at 40% 80%, rgba(59, 130, 246, 0.4) 0%, transparent 60%),
        radial-gradient(circle at 60% 20%, rgba(16, 185, 129, 0.4) 0%, transparent 60%),
        radial-gradient(circle at 30% 60%, rgba(245, 101, 101, 0.3) 0%, transparent 70%);
    filter: blur(40px);
    opacity: 1;
    z-index: -1;
    animation: gradientShift 25s ease-in-out infinite;
}

[data-theme="dark"] body::before {
    background: 
        radial-gradient(circle at 20% 30%, rgba(67, 56, 202, 0.8) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(219, 39, 119, 0.8) 0%, transparent 50%),
        radial-gradient(circle at 40% 80%, rgba(59, 130, 246, 0.8) 0%, transparent 50%),
        radial-gradient(circle at 60% 20%, rgba(16, 185, 129, 0.8) 0%, transparent 50%);
    filter: blur(70px);
    opacity: 0.9;
}

@keyframes gradientShift {
    0%, 100% {
        transform: translateX(0) translateY(0) scale(1);
    }
    25% {
        transform: translateX(-10px) translateY(-20px) scale(1.1);
    }
    50% {
        transform: translateX(10px) translateY(10px) scale(0.9);
    }
    75% {
        transform: translateX(20px) translateY(-10px) scale(1.05);
    }
}

/* Enhanced theme transition */
.theme-transitioning * {
    transition: background-color 0.3s cubic-bezier(0.4, 0, 0.2, 1), 
                color 0.3s cubic-bezier(0.4, 0, 0.2, 1), 
                border-color 0.3s cubic-bezier(0.4, 0, 0.2, 1),
                box-shadow 0.3s cubic-bezier(0.4, 0, 0.2, 1) !important;
}

.app-container {
    display: flex;
    height: 100vh;
    background: rgba(255, 255, 255, 0.4);
    backdrop-filter: blur(20px);
    transition: background-color 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] .app-container {
    background: rgba(15, 15, 15, 0.6);
}

/* Sidebar Styles */
.sidebar {
    width: 280px;
    background: rgba(255, 255, 255, 0.5);
    backdrop-filter: blur(15px);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    padding: 20px 16px;
    position: relative;
    transition: background-color 0.3s cubic-bezier(0.4, 0, 0.2, 1), border-color 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] .sidebar {
    background: rgba(17, 17, 17, 0.7);
    backdrop-filter: blur(10px);
}

.sidebar-header {
    margin-bottom: 24px;
}

.logo-container {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 8px;
}

.logo-icon {
    width: 32px;
    height: 32px;
    background: var(--gradient-primary);
    border-radius: var(--border-radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

.sidebar-header h2 {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0;
}

.powered-by {
    font-size: 12px;
    color: var(--text-muted);
    margin-left: 44px;
}

.new-chat-btn button {
    width: 100%;
    padding: 12px 16px;
    background: var(--secondary-bg);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    box-shadow: var(--shadow-sm);
}

.new-chat-btn button:hover {
    background: var(--primary-bg);
    border-color: var(--accent-color);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.conversation-history {
    flex: 1;
    margin-top: 24px;
    overflow-y: auto;
}

.history-section h3 {
    font-size: 12px;
    font-weight: 600;
    color: var(--text-muted);
    margin-bottom: 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

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

.chat-history-item:hover {
    background: var(--secondary-bg);
    box-shadow: var(--shadow-sm);
}

.chat-icon {
    width: 20px;
    height: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
}

.chat-history-item span {
    font-size: 13px;
    color: var(--text-secondary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

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

.user-profile {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px 12px;
    border-radius: var(--border-radius-sm);
    transition: background 0.2s ease;
    justify-content: space-between;
}

.user-profile:hover {
    background: var(--secondary-bg);
}

.avatar-small {
    width: 24px;
    height: 24px;
    background: var(--gradient-secondary);
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

.user-profile span {
    font-size: 13px;
    color: var(--text-secondary);
    font-weight: 500;
    flex: 1;
    margin-left: 4px;
}

/* Settings button in sidebar */
.settings-btn {
    width: 32px;
    height: 32px;
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    transition: all 0.2s ease;
    opacity: 1;
    transform: translateX(0);
}

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

/* Main Content Styles */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: rgba(255, 255, 255, 0.4);
    backdrop-filter: blur(15px);
    position: relative;
}

[data-theme="dark"] .main-content {
    background: rgba(26, 26, 26, 0.6);
    backdrop-filter: blur(10px);
}

.chat-header-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 24px;
    border-bottom: 1px solid var(--border-light);
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(8px);
}

[data-theme="dark"] .chat-header-bar {
    background: rgba(26, 26, 26, 0.3);
    backdrop-filter: blur(8px);
}

.chat-title h1 {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
}

.chat-actions {
    display: flex;
    gap: 8px;
}

.action-btn {
    width: 36px;
    height: 36px;
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    transition: all 0.2s ease;
}

.action-btn:hover {
    background: var(--primary-bg);
    border-color: var(--accent-color);
    color: var(--accent-color);
}

/* Theme Toggle Styles */
.theme-toggle {
    width: 60px;
    height: 32px;
    background: transparent;
    border: 2px solid var(--border-color);
    border-radius: 20px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: flex-start;
    padding: 2px;
    margin-right: 8px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.theme-toggle:hover {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.theme-toggle-track {
    width: 100%;
    height: 100%;
    position: relative;
    border-radius: 18px;
    background: linear-gradient(135deg, #e9e5ddff 0%, #ebe6ddff 100%);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] .theme-toggle-track {
    background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
}

.theme-toggle-thumb {
    width: 24px;
    height: 24px;
    background: white;
    border-radius: 50%;
    position: absolute;
    top: 50%;
    left: 2px;
    transform: translateY(-50%);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
    overflow: hidden;
}

[data-theme="dark"] .theme-toggle-thumb {
    left: calc(100% - 26px);
    background: #1f2937;
}

.theme-icon {
    position: absolute;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.sun-icon {
    color: #f59e0b;
    opacity: 1;
    transform: rotate(0deg) scale(1);
}

[data-theme="dark"] .sun-icon {
    opacity: 0;
    transform: rotate(180deg) scale(0.5);
}

.moon-icon {
    color: #60a5fa;
    opacity: 0;
    transform: rotate(-180deg) scale(0.5);
}

[data-theme="dark"] .moon-icon {
    opacity: 1;
    transform: rotate(0deg) scale(1);
}

.chat-container {
    flex: 1;
    overflow-y: auto;
    padding: 0;
    display: flex;
    flex-direction: column;
}

/* Welcome Section */
.welcome-section {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px 24px;
}

.welcome-content {
    text-align: center;
    max-width: 600px;
}

.lexara-avatar {
    margin: 0 auto 24px;
    width: 80px;
    height: 80px;
    position: relative;
}

.avatar-gradient {
    width: 100%;
    height: 100%;
    background: var(--gradient-primary);
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    box-shadow: var(--shadow-lg);
}

.welcome-content h1 {
    font-size: 32px;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.welcome-content p {
    font-size: 16px;
    color: var(--text-secondary);
    margin-bottom: 32px;
    line-height: 1.6;
}

.quick-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    justify-content: center;
    max-width: 700px;
    margin: 0 auto;
}

[data-theme="dark"] .quick-action-btn {
    background-color: #1e1e1e;
    border-color: #333;
    color: #e0e0e0;
}

[data-theme="dark"] .quick-action-btn:hover {
    background-color: #2a2a2a;
    border-color: #555;
    color: #fff;
}

.quick-action-btn {
    background-color: var(--secondary-bg);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    color: var(--text-primary);
    padding: 10px 16px;
    font-size: 14px;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    transition: all 0.2s ease-in-out;
    box-shadow: var(--shadow-sm);
}

.quick-action-btn:hover {
    background-color: var(--primary-bg);
    border-color: var(--accent-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.quick-action-btn i {
    width: 20px;
    height: 20px;
    margin-right: 6px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

/* Icon colors for each action */
.quick-action-btn[data-prompt="Summarize text"] i {
    color: #ff9a3c;
}
.quick-action-btn[data-prompt="Get advice"] i {
    color: #36a2eb;
}
.quick-action-btn[data-prompt="Surprise me"] i {
    color: #ff6384;
}
.quick-action-btn[data-prompt="Analyze data"] i {
    color: #4bc0c0;
}
.quick-action-btn[data-prompt="Help me write"] i {
    color: #9966ff;
}
.quick-action-btn[data-prompt="More"] i {
    color: #b0b0b0;
}

/* Chat Messages */
.chat-messages {
    padding: 24px;
    max-width: 800px;
    margin: 0 auto;
    width: 100%;
}

.message {
    display: flex;
    gap: 16px;
    margin-bottom: 24px;
    animation: slideUp 0.3s ease;
}

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

.message-avatar {
    flex-shrink: 0;
    margin-top: 4px;
}

.avatar {
    width: 32px;
    height: 32px;
    border-radius: var(--border-radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    font-weight: 600;
}

.user-avatar {
    background: var(--gradient-secondary);
    color: white;
}

.lexara-avatar-small {
    background: var(--gradient-primary);
    color: white;
}

.message-content {
    flex: 1;
    line-height: 1.6;
}

.user-message .message-content {
    background: var(--primary-bg);
    padding: 16px 20px;
    border-radius: 18px 18px 4px 18px;
    border: 1px solid var(--border-light);
    max-width: fit-content;
    box-shadow: var(--shadow-sm);
}

.assistant-message .message-content {
    background: transparent;
}

.message-content p {
    margin-bottom: 12px;
    color: var(--text-primary);
}

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

/* Code Blocks */
.message-content pre {
    background: #1a1b26;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 16px;
    margin: 16px 0;
    overflow-x: auto;
    font-family: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', monospace;
    font-size: 13px;
    line-height: 1.5;
}

.message-content code {
    background: var(--primary-bg);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', monospace;
    font-size: 13px;
    border: 1px solid var(--border-light);
}

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

/* Typing Indicator */
.typing-indicator {
    padding: 0 24px;
    max-width: 800px;
    margin: 0 auto;
    width: 100%;
}

.typing-dots {
    display: flex;
    gap: 4px;
    padding: 16px 0;
}

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

.typing-dots span:nth-child(1) { animation-delay: -0.32s; }
.typing-dots span:nth-child(2) { animation-delay: -0.16s; }

@keyframes typing {
    0%, 80%, 100% {
        transform: scale(0.8);
        opacity: 0.4;
    }
    40% {
        transform: scale(1);
        opacity: 1;
    }
}

/* Input Container */
.input-container {
    padding: 20px 24px;
    border-top: 1px solid var(--border-light);
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(8px);
}

[data-theme="dark"] .input-container {
    background: rgba(26, 26, 26, 0.3);
    backdrop-filter: blur(8px);
}

.input-wrapper {
    max-width: 800px;
    margin: 0 auto;
}

.input-field {
    position: relative;
    background: var(--primary-bg);
    border: 2px solid var(--border-color);
    border-radius: 24px;
    display: flex;
    align-items: flex-end;
    padding: 4px;
    gap: 8px;
    transition: border-color 0.2s ease;
}

.input-field:focus-within {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(118, 75, 162, 0.18);
}

#messageInput {
    flex: 1;
    background: transparent;
    border: none;
    outline: none;
    color: var(--text-primary);
    font-size: 15px;
    line-height: 1.5;
    resize: none;
    min-height: 20px;
    max-height: 120px;
    overflow-y: auto;
    font-family: inherit;
    padding: 12px 16px;
}

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

.input-actions {
    display: flex;
    align-items: flex-end;
    gap: 4px;
    padding: 4px;
}

#sendButton {
    width: 32px;
    height: 32px;
    background: var(--accent-color);
    border: none;
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    transition: all 0.2s ease;
}

#sendButton:disabled {
    background: var(--border-color);
    cursor: not-allowed;
}

#sendButton:disabled svg {
    color: var(--text-muted);
}

#sendButton:hover:not(:disabled) {
    background: var(--accent-hover);
    transform: scale(1.05);
}

.input-footer {
    text-align: center;
    margin-top: 12px;
}

.input-footer p {
    font-size: 12px;
    color: var(--text-muted);
}

/* Enhanced Mobile-First Responsive Design */
@media (max-width: 1024px) {
    .sidebar {
        width: 250px;
    }
    
    .chat-messages {
        padding: 16px;
    }
}

@media (max-width: 768px) {
    .app-container {
        flex-direction: column;
        height: 100vh;
        overflow: hidden;
    }
    
    .sidebar {
        width: 100%;
        height: auto;
        min-height: 60px;
        max-height: 50vh;
        border-right: none;
        border-bottom: 1px solid var(--border-color);
        order: 2;
        overflow-y: auto;
        padding: 12px;
        position: relative;
    }
    
    .sidebar-header {
        margin-bottom: 16px;
    }
    
    .sidebar-header h2 {
        font-size: 18px;
    }
    
    .conversation-history {
        max-height: 200px;
        overflow-y: auto;
    }
    
    .main-content {
        order: 1;
        flex: 1;
        display: flex;
        flex-direction: column;
        min-height: 0;
    }
    
    .chat-header-bar {
        padding: 12px 16px;
        flex-shrink: 0;
    }
    
    .chat-container {
        flex: 1;
        min-height: 0;
        display: flex;
        flex-direction: column;
    }
    
    .welcome-content h1 {
        font-size: 24px;
    }
    
    .quick-actions {
        grid-template-columns: repeat(2, 1fr);
        gap: 12px;
        max-width: 100%;
    }
    
    .quick-action-card {
        padding: 16px 12px;
    }
    
    .chat-messages {
        padding: 12px 16px;
        flex: 1;
        overflow-y: auto;
    }
    
    .message {
        margin-bottom: 16px;
    }
    
    .message-content {
        max-width: calc(100% - 50px);
    }
    
    .input-container {
        padding: 12px 16px;
        flex-shrink: 0;
    }
    
    .input-wrapper {
        max-width: 100%;
    }
    
    .theme-toggle {
        width: 64px;
        height: 36px;
        min-width: 64px;
        min-height: 36px;
        padding: 4px;
        border-width: 2.5px;
    }
    .theme-toggle-thumb {
        width: 28px;
        height: 28px;
        top: 50%;
        left: 4px;
        transform: translateY(-50%);
        display: flex;
        align-items: center;
        justify-content: center;
        box-shadow: 0 2px 8px rgba(0,0,0,0.12);
    }
    [data-theme="dark"] .theme-toggle-thumb {
        left: calc(100% - 32px);
    }
    .theme-icon {
        width: 18px !important;
        height: 18px !important;
        display: block;
        margin: 0 auto;
    }
}

@media (max-width: 640px) {
    .sidebar {
        max-height: 40vh;
        padding: 8px 12px;
    }
    
    .chat-header-bar {
        padding: 8px 12px;
    }
    
    .chat-title h1 {
        font-size: 16px;
    }
    
    .action-btn {
        width: 32px;
        height: 32px;
    }
    
    .theme-toggle {
        width: 45px;
        height: 24px;
        margin-right: 6px;
    }
    
    .theme-toggle-thumb {
        width: 18px;
        height: 18px;
    }
    
    [data-theme="dark"] .theme-toggle-thumb {
        left: calc(100% - 20px);
    }
    
    .welcome-content {
        padding: 16px;
        text-align: center;
    }
    
    .welcome-content h1 {
        font-size: 20px;
        margin-bottom: 8px;
    }
    
    .welcome-content div {
        font-size: 22px !important;
        margin-bottom: 16px;
    }
    
    .quick-actions {
        grid-template-columns: 1fr 1fr;
        gap: 10px;
        margin-top: 16px;
    }
    
    .quick-action-card {
        padding: 14px 10px;
        border-radius: 12px;
    }
    
    .chat-messages {
        padding: 8px 12px;
    }
    
    .message {
        margin-bottom: 12px;
    }
    
    .message-avatar {
        width: 32px;
        height: 32px;
        margin-right: 8px;
    }
    
    .avatar {
        width: 32px;
        height: 32px;
    }
    
    .message-content {
        max-width: calc(100% - 45px);
        font-size: 14px;
        line-height: 1.5;
    }
    
    .input-container {
        padding: 8px 12px;
    }
    
    .input-wrapper textarea {
        font-size: 16px; /* Prevents zoom on iOS */
        min-height: 44px; /* iOS touch target minimum */
        padding: 12px 16px;
    }
    
    .input-actions {
        gap: 8px;
    }
    
    #sendButton {
        width: 44px; /* iOS touch target minimum */
        height: 44px;
        min-width: 44px;
        min-height: 44px;
    }
}

@media (max-width: 480px) {
    .sidebar {
        position: fixed;
        top: 0;
        left: -100%;
        width: 280px;
        height: 100vh;
        z-index: 1000;
        transition: left 0.3s ease;
        border-right: 1px solid var(--border-color);
        border-bottom: none;
        order: unset;
        max-height: unset;
        background: var(--sidebar-bg);
        padding: 16px;
    }
    
    .sidebar.mobile-open {
        left: 0;
    }
    
    .sidebar-overlay {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: rgba(0, 0, 0, 0.5);
        z-index: 999;
        display: none;
    }
    
    .sidebar-overlay.active {
        display: block;
    }
    
    .main-content {
        order: unset;
        width: 100%;
    }
    
    .chat-header-bar {
        padding: 8px 12px;
        position: relative;
    }
    
    .chat-header-bar::before {
        content: '';
        position: absolute;
        left: 12px;
        top: 50%;
        transform: translateY(-50%);
        width: 20px;
        height: 20px;
        background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='20' height='20' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='2'%3E%3Cline x1='3' y1='6' x2='21' y2='6'/%3E%3Cline x1='3' y1='12' x2='21' y2='12'/%3E%3Cline x1='3' y1='18' x2='21' y2='18'/%3E%3C/svg%3E");
        cursor: pointer;
        opacity: 0.7;
    }
    
    .chat-title {
        margin-left: 35px;
    }
    
    .chat-title h1 {
        font-size: 15px;
    }
    
    .welcome-content {
        padding: 12px;
    }
    
    .welcome-content h1 {
        font-size: 18px;
    }
    
    .welcome-content div {
        font-size: 18px !important;
    }
    
    .quick-actions {
        grid-template-columns: 1fr;
        gap: 8px;
        max-width: 300px;
    }
    
    .quick-action-card {
        padding: 16px;
        text-align: left;
        display: flex;
        align-items: center;
        gap: 12px;
    }
    
    .action-icon {
        font-size: 20px;
        margin-bottom: 0;
        flex-shrink: 0;
    }
    
    .quick-action-card span {
        font-size: 14px;
        text-transform: none;
        letter-spacing: normal;
    }
    
    .chat-messages {
        padding: 6px 8px 16px 8px;
    }
    
    .input-wrapper textarea {
        max-height: 120px;
    }
    
    /* User profile mobile adjustments */
    .user-profile {
        padding: 6px 8px;
        gap: 8px;
    }
    
    .user-profile span {
        font-size: 12px;
    }
    
    .settings-btn {
        width: 28px;
        height: 28px;
    }
    
    /* Mobile-specific touch improvements */
    .chat-history-item {
        min-height: 44px;
        padding: 8px 12px;
        display: flex;
        align-items: center;
    }
    
    .chat-history-item span {
        font-size: 13px;
    }
    
    /* Safe area for notched phones */
    .chat-header-bar {
        padding-top: max(8px, env(safe-area-inset-top));
    }
    
    .input-container {
        padding-bottom: max(8px, env(safe-area-inset-bottom));
    }
}

/* Landscape phone orientation */
@media (max-width: 896px) and (max-height: 414px) and (orientation: landscape) {
    .sidebar {
        width: 240px;
    }
    
    .welcome-content {
        padding: 8px;
    }
    
    .welcome-content h1 {
        font-size: 16px;
        margin-bottom: 4px;
    }
    
    .welcome-content div {
        font-size: 16px !important;
        margin-bottom: 8px;
    }
    
    .quick-actions {
        grid-template-columns: repeat(3, 1fr);
        gap: 6px;
    }
    
    .quick-action-card {
        padding: 8px 6px;
    }
    
    .action-icon {
        font-size: 18px;
    }
    
    .quick-action-card span {
        font-size: 11px;
    }
}

/* High DPI screens */
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
    .theme-toggle-track,
    .theme-toggle-thumb {
        transform: translateZ(0);
        -webkit-font-smoothing: antialiased;
    }
}

/* Scrollbar Styling */
.chat-container::-webkit-scrollbar,
.conversation-history::-webkit-scrollbar {
    width: 6px;
}

.chat-container::-webkit-scrollbar-track,
.conversation-history::-webkit-scrollbar-track {
    background: transparent;
}

.chat-container::-webkit-scrollbar-thumb,
.conversation-history::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 3px;
}

.chat-container::-webkit-scrollbar-thumb:hover,
.conversation-history::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}