/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* ChatGPT color scheme */
    --bg-primary: #171717;
    --bg-secondary: #202123;
    --bg-tertiary: #2d2d30;
    --bg-sidebar: #171717;
    --bg-chat: #333333;
    --bg-user: #2f2f2f;
    --bg-assistant: #333333;
    --bg-hover: #2a2a2c;
    --bg-input: #2d2d30;
    --text-primary: #ececf1;
    --text-secondary: #b4b4b4;
    --text-muted: #8e8ea0;
    --text-primary-light: #374151;
    --text-secondary-light: #6b7280;
    --accent-primary: #10a37f;
    --accent-secondary: #19c37d;
    --border-primary: #4a4a4a;
    --border-secondary: #3e3e3e;
    --shadow-primary: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-elevated: 0 4px 8px rgba(0, 0, 0, 0.15);
    --border-radius: 8px;
    --transition: all 0.2s ease;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow: hidden;
}

/* App Container */
.app-container {
    display: flex;
    height: 100vh;
    width: 100vw;
}

/* Sidebar Styles */
.sidebar {
    width: 260px;
    background-color: var(--bg-sidebar);
    display: flex;
    flex-direction: column;
    position: relative;
    z-index: 100;
    transition: var(--transition);
}

.sidebar-header {
    padding: 12px;
}

.new-chat-btn {
    width: 100%;
    background: transparent;
    border: none;
    color: var(--text-primary);
    padding: 12px 16px;
    border-radius: var(--border-radius);
    font-size: 14px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: var(--transition);
}

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

.new-chat-btn i {
    font-size: 12px;
}

/* Chat History */
.chat-history {
    flex: 1;
    padding: 8px;
    overflow-y: auto;
}

.chat-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    margin: 2px 0;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    color: var(--text-secondary);
}

.chat-item:hover {
    background-color: var(--bg-hover);
}

.chat-item.active {
    background-color: var(--bg-hover);
    color: var(--text-primary);
}

.chat-item i {
    font-size: 14px;
    width: 16px;
    text-align: center;
}

.chat-item span {
    font-size: 14px;
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* Sidebar Footer */
.sidebar-footer {
    padding: 12px;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px 12px;
    color: var(--text-secondary);
}

.avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}

.avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 50%;
}

/* Sidebar Toggle for Mobile */
.sidebar-toggle {
    display: none;
    position: fixed;
    top: 16px;
    left: 16px;
    z-index: 1000;
    background: var(--bg-tertiary);
    border: none;
    color: var(--text-primary);
    padding: 8px;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
}

.sidebar-toggle:hover {
    background: var(--bg-hover);
}

/* Chat Container */
.chat-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    background-color: var(--bg-chat);
    position: relative;
    overflow: hidden;
}

/* Chat Header */
.chat-header {
    padding: 12px 24px;
    display: flex;
    justify-content: flex-start;
    align-items: center;
    background-color: var(--bg-assistant);
}

/* Language Selector */
.language-selector {
    position: relative;
}

.language-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: var(--bg-assistant);
    border: none;
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 14px;
    cursor: pointer;
    transition: var(--transition);
    min-width: 120px;
}

.language-btn:hover {
    background: var(--bg-hover);
}

.language-btn i:first-child {
    color: var(--accent-primary);
    font-size: 16px;
}

.language-btn i:last-child {
    font-size: 12px;
    margin-left: auto;
    transition: transform 0.2s ease;
}

.language-btn.active i:last-child {
    transform: rotate(180deg);
}

.language-dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    margin-top: 4px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-primary);
    border-radius: 8px;
    box-shadow: var(--shadow-elevated);
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: all 0.2s ease;
}

.language-dropdown.active {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.language-option {
    padding: 12px 16px;
    color: var(--text-primary);
    cursor: pointer;
    transition: var(--transition);
    border-radius: 6px;
    margin: 4px;
}

.language-option:hover {
    background: var(--bg-hover);
}

.language-option.selected {
    background: var(--accent-primary);
    color: white;
}


/* Chat Messages */
.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 24px 0;
    scroll-behavior: smooth;
}

/* Text color adjustments for dark gray background */
.chat-messages .message-text,
.chat-messages .message-text p,
.chat-messages .message-text li,
.chat-messages .message-text h3,
.chat-messages .message-text strong {
    color: var(--text-primary) !important;
}

.chat-messages .authors,
.chat-messages .venue {
    color: var(--text-secondary) !important;
}

.message {
    margin-bottom: 24px;
    padding: 0 24px;
    animation: fadeInUp 0.3s ease;
}

.message-content {
    max-width: 768px;
    margin: 0 auto;
    display: flex;
    gap: 16px;
}

.message-avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 16px;
    flex-shrink: 0;
}

.message.user .message-avatar {
    background-color: var(--accent-primary);
    color: white;
}

.message.assistant .message-avatar {
    background-color: var(--accent-secondary);
    color: white;
    overflow: hidden;
}

.message-text {
    flex: 1;
    padding-top: 6px;
}

.message.user {
    background-color: var(--bg-assistant);
}

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

.message.assistant {
    background-color: var(--bg-assistant);
}

.message-text h3 {
    color: var(--accent-primary);
    margin-bottom: 12px;
    font-size: 18px;
    font-weight: 600;
}

.message-text p {
    margin-bottom: 12px;
    line-height: 1.6;
    color: var(--text-primary);
}

.message-text ul, .message-text ol {
    margin: 12px 0;
    padding-left: 20px;
}

.message-text li {
    margin-bottom: 8px;
    color: var(--text-primary);
}

.message-text strong {
    color: var(--accent-secondary);
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin: 12px 0;
}

.skill-tag {
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
    padding: 4px 12px;
    border-radius: 16px;
    font-size: 12px;
    border: 1px solid var(--border-primary);
    transition: var(--transition);
}

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

.publication-item {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-primary);
    border-radius: var(--border-radius);
    padding: 16px;
    margin: 12px 0;
    transition: var(--transition);
}

.publication-item:hover {
    border-color: var(--accent-primary);
}

.publication-item h4 {
    color: var(--text-primary);
    margin-bottom: 8px;
    font-size: 16px;
}

.publication-item .authors {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 4px;
}

.publication-item .venue {
    color: var(--text-muted);
    font-size: 13px;
    font-style: italic;
}

.contact-info {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-primary);
    border-radius: var(--border-radius);
    padding: 16px;
    margin: 12px 0;
}

.contact-methods {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 12px;
    margin-top: 12px;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    background-color: var(--bg-hover);
    border-radius: var(--border-radius);
    transition: var(--transition);
    cursor: pointer;
}

.contact-item:hover {
    background-color: var(--bg-user);
}

.contact-item i {
    color: var(--accent-primary);
    width: 16px;
}

/* Chat Input */
.chat-input-container {
    padding: 24px;
    background-color: var(--bg-assistant);
}

.chat-input-wrapper {
    max-width: 768px;
    margin: 0 auto;
    position: relative;
    display: flex;
    align-items: flex-end;
    gap: 8px;
    background-color: var(--bg-input);
    border: 1px solid var(--border-primary);
    border-radius: 24px;
    padding: 12px 16px;
    transition: var(--transition);
}

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

#chatInput {
    flex: 1;
    background: transparent;
    border: none;
    outline: none;
    color: var(--text-primary-light);
    font-size: 16px;
    resize: none;
    max-height: 120px;
    min-height: 24px;
    line-height: 1.5;
    font-family: inherit;
}

#chatInput::placeholder {
    color: var(--text-secondary-light);
}

#chatInput:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.send-btn {
    background: var(--accent-primary);
    border: none;
    border-radius: 50%;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition);
    color: white;
}

.send-btn:hover:not(:disabled) {
    background: var(--accent-secondary);
}

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

.input-note {
    text-align: center;
    color: var(--text-muted);
    font-size: 12px;
    margin-top: 8px;
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes typing {
    0%, 50% {
        opacity: 1;
    }
    51%, 100% {
        opacity: 0;
    }
}

.typing-indicator {
    display: inline-block;
    animation: typing 1.5s infinite;
}

/* Scrollbar Styles */
.chat-messages::-webkit-scrollbar,
.chat-history::-webkit-scrollbar {
    width: 6px;
}

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

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

.chat-messages::-webkit-scrollbar-thumb:hover,
.chat-history::-webkit-scrollbar-thumb:hover {
    background: var(--border-secondary);
}

/* Mobile Responsive */
@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        left: -260px;
        top: 0;
        height: 100vh;
        z-index: 1000;
        transition: left 0.3s ease;
    }
    
    .sidebar.open {
        left: 0;
    }
    
    .sidebar-toggle {
        display: block;
    }
    
    .chat-container {
        width: 100%;
    }
    
    .message {
        padding: 0 16px;
    }
    
    .chat-input-container {
        padding: 16px;
    }
    
}

@media (max-width: 480px) {
    .chat-header {
        padding: 12px 16px;
    }
    
    .chat-header h1 {
        font-size: 18px;
    }
    
    .message-content {
        gap: 12px;
    }
    
    .message-avatar {
        width: 28px;
        height: 28px;
        font-size: 14px;
    }
    
    .contact-methods {
        grid-template-columns: 1fr;
    }
    
    .skill-tags {
        gap: 6px;
    }
    
    .skill-tag {
        font-size: 11px;
        padding: 3px 8px;
    }
}

/* Dark mode enhancements */
@media (prefers-color-scheme: dark) {
    body {
        background-color: var(--bg-primary);
    }
}

/* Focus states for accessibility */
.chat-item:focus,
.new-chat-btn:focus,
.contact-item:focus {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
}

#chatInput:focus {
    outline: none;
}

/* Loading animation */
.loading-dots {
    display: inline-flex;
    gap: 4px;
}

.loading-dots span {
    width: 4px;
    height: 4px;
    background-color: var(--text-muted);
    border-radius: 50%;
    animation: loading 1.4s infinite;
}

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

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

@keyframes loading {
    0%, 80%, 100% {
        opacity: 0.3;
        transform: scale(0.8);
    }
    40% {
        opacity: 1;
        transform: scale(1);
    }
}