/* ===== CSS Variables ===== */
:root {
    /* Dark Theme (Default) */
    --bg-primary: #0a0a0b;
    --bg-secondary: #141416;
    --bg-tertiary: #1f1f23;
    --bg-hover: #28282e;
    --text-primary: #f0f0f3;
    --text-secondary: #a8a8b3;
    --accent-blue: #6b9eff;
    --accent-purple: #a78bfa;
    --accent-glow: rgba(107, 158, 255, 0.15);
    --border-color: #2a2a32;
    --message-user-bg: #1a1a1f;
    --message-ai-bg: transparent;
    --sidebar-width: 260px;
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-secondary: linear-gradient(135deg, #6b9eff 0%, #a78bfa 100%);
}

/* Light Theme */
:root[data-theme="light"] {
    --bg-primary: #fafafa;
    --bg-secondary: #ffffff;
    --bg-tertiary: #f5f5f7;
    --bg-hover: #ebebed;
    --text-primary: #1a1a1f;
    --text-secondary: #6e6e73;
    --accent-blue: #0066cc;
    --accent-purple: #7c3aed;
    --accent-glow: rgba(0, 102, 204, 0.08);
    --border-color: #e5e5e7;
    --message-user-bg: #f5f5f7;
    --message-ai-bg: transparent;
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-secondary: linear-gradient(135deg, #0066cc 0%, #7c3aed 100%);
}

/* ===== Global Styles ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Inter', 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow: hidden;
    transition: background-color 0.3s ease, color 0.3s ease;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ===== Container Layout ===== */
.container {
    display: flex;
    height: 100vh;
    width: 100vw;
}

/* ===== Sidebar Styles ===== */
.sidebar {
    width: var(--sidebar-width);
    background: var(--bg-secondary);
    display: flex;
    flex-direction: column;
    border-right: 1px solid var(--border-color);
    transition: transform 0.3s ease;
    backdrop-filter: blur(20px);
}

.sidebar-header {
    display: flex;
    align-items: center;
    padding: 16px;
    gap: 12px;
}

.menu-toggle {
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 24px;
    cursor: pointer;
    padding: 8px;
    border-radius: 50%;
    transition: background-color 0.2s;
    display: none; /* Hidden on desktop */
}

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

.logo {
    font-size: 20px;
    font-weight: 600;
    background: var(--gradient-secondary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.5px;
}

/* New Chat Button */
.new-chat-section {
    padding: 8px 16px;
}

.new-chat-btn {
    width: 100%;
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    color: var(--text-primary);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.new-chat-btn:hover {
    background: var(--hover-bg);
    transform: translateY(-1px);
}

.new-chat-btn.active {
    background: var(--gradient-secondary);
    border-color: transparent;
    color: white;
    box-shadow: 0 2px 8px rgba(107, 158, 255, 0.2);
}

.new-chat-btn.active:hover {
    box-shadow: 0 4px 12px rgba(107, 158, 255, 0.3);
}

/* Navigation Menu */
.nav-menu {
    flex: 1;
    overflow-y: auto;
    padding: 8px;
}

.menu-section {
    margin-bottom: 24px;
}

.section-title {
    font-size: 11px;
    font-weight: 500;
    color: var(--text-secondary);
    padding: 8px 16px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.menu-list {
    list-style: none;
}

.menu-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 16px;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    margin-bottom: 4px;
    position: relative;
}

.menu-item::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 3px;
    height: 0;
    background: var(--gradient-secondary);
    border-radius: 0 2px 2px 0;
    transition: height 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

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

.menu-item:hover::before {
    height: 60%;
}

.menu-item.active {
    background: var(--bg-tertiary);
    border-left: 3px solid transparent;
}

.menu-item.active::before {
    height: 70%;
}

.menu-icon {
    font-size: 18px;
}

.menu-text {
    font-size: 14px;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* Sidebar Footer */
.sidebar-footer {
    padding: 16px;
    border-top: 1px solid var(--border-color);
}

.settings-btn {
    width: 100%;
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    background: none;
    border: none;
    border-radius: 24px;
    color: var(--text-primary);
    font-size: 14px;
    cursor: pointer;
    transition: background-color 0.2s;
}

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

/* ===== Main Chat Area ===== */
.chat-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    background-color: var(--bg-primary);
}

/* Chat Header */
.chat-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 24px;
    border-bottom: 1px solid var(--border-color);
    position: relative;
    backdrop-filter: blur(20px);
    background: var(--bg-secondary);
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 24px;
    cursor: pointer;
    padding: 8px 12px;
    border-radius: 8px;
    transition: background-color 0.2s;
    position: absolute;
    left: 16px;
    z-index: 10;
}

.mobile-menu-btn:hover {
    background-color: var(--bg-hover);
}

.mobile-menu-btn:active {
    background-color: var(--bg-tertiary);
}

.chat-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    letter-spacing: -0.3px;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 12px;
}

.pro-badge {
    padding: 6px 14px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    font-size: 12px;
    color: var(--accent-blue);
    font-weight: 600;
    letter-spacing: 0.3px;
}

/* Theme Toggle Button */
.theme-toggle-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    font-size: 20px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
}

.theme-toggle-btn:hover {
    background-color: var(--bg-hover);
    transform: scale(1.05);
}

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

/* Welcome Screen */
.welcome-screen {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
    padding-top: 10vh;
}

.welcome-title {
    font-size: 56px;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text-primary);
    letter-spacing: -1.5px;
    line-height: 1.1;
}

.highlight {
    background: var(--gradient-secondary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 700;
}

.welcome-subtitle {
    font-size: 20px;
    color: var(--text-secondary);
    margin-bottom: 48px;
}

/* Witty Quote */
.witty-quote {
    margin: 32px auto 48px;
    max-width: 600px;
    padding: 28px 32px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-left: 3px solid var(--accent-blue);
    border-radius: 16px;
    position: relative;
    animation: slideInUp 0.6s ease-out;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

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

.quote-text {
    font-size: 17px;
    line-height: 1.7;
    color: var(--text-primary);
    margin: 0;
    font-weight: 400;
    text-align: left;
}

.quote-highlight {
    color: var(--accent-blue);
    font-weight: 600;
    font-size: 18px;
    display: inline-block;
    margin-top: 4px;
}

/* Quick Action Buttons */
.quick-actions {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 16px;
    margin-bottom: 48px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.action-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    padding: 28px 20px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    color: var(--text-primary);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.action-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--gradient-secondary);
    opacity: 0;
    transition: opacity 0.3s ease;
    z-index: 0;
}

.action-btn:hover::before {
    opacity: 0.08;
}

.action-btn:hover {
    border-color: var(--accent-blue);
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(107, 158, 255, 0.15);
}

.action-btn span {
    position: relative;
    z-index: 1;
}

.emoji {
    font-size: 32px;
}

.learn-section {
    margin-top: 32px;
}

.learn-text {
    color: var(--text-secondary);
    font-size: 14px;
}

/* Chat Content (Messages) */
.chat-content {
    max-width: 900px;
    margin: 0 auto;
}

.message {
    margin-bottom: 32px;
    animation: fadeIn 0.4s ease-in;
}

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

.message-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 12px;
}

.avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    background-color: var(--bg-tertiary);
}

.sender-name {
    font-weight: 500;
    font-size: 14px;
    color: var(--text-primary);
}

.message-content {
    margin-left: 44px;
    color: var(--text-primary);
    line-height: 1.8;
}

.message-content h2 {
    font-size: 28px;
    margin-bottom: 20px;
    background: var(--gradient-secondary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 700;
    letter-spacing: -0.5px;
}

.message-content h3 {
    font-size: 20px;
    margin-top: 28px;
    margin-bottom: 14px;
    color: var(--text-primary);
    font-weight: 600;
    letter-spacing: -0.3px;
}

.message-content p {
    margin-bottom: 16px;
    font-size: 15px;
}

.message-content ul, .message-content ol {
    margin-left: 24px;
    margin-bottom: 16px;
}

.message-content li {
    margin-bottom: 8px;
    font-size: 15px;
}

.message-content img {
    max-width: 100%;
    border-radius: 12px;
    margin: 16px 0;
}

.message-content video {
    max-width: 100%;
    border-radius: 12px;
    margin: 16px 0;
}

/* Skill Tags */
.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin: 16px 0;
}

.skill-tag {
    padding: 8px 16px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 13px;
    font-weight: 500;
    color: var(--text-primary);
    transition: all 0.2s ease;
}

.skill-tag:hover {
    background: var(--bg-hover);
    border-color: var(--accent-blue);
    transform: translateY(-1px);
}

/* Project Cards */
.project-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 28px;
    margin: 20px 0;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.project-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--gradient-secondary);
    opacity: 0;
    transition: opacity 0.3s ease;
    z-index: 0;
}

.project-card:hover::before {
    opacity: 0.03;
}

.project-card:hover {
    border-color: var(--accent-blue);
    transform: translateY(-4px);
    box-shadow: 0 12px 32px rgba(107, 158, 255, 0.12);
}

.project-card > * {
    position: relative;
    z-index: 1;
}

.project-title {
    font-size: 20px;
    color: var(--accent-blue);
    margin-bottom: 12px;
    font-weight: 600;
    letter-spacing: -0.3px;
}

.project-description {
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.project-links {
    display: flex;
    gap: 12px;
}

.project-link {
    padding: 10px 18px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    color: var(--accent-blue);
    text-decoration: none;
    font-size: 13px;
    font-weight: 500;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    display: inline-block;
}

.project-link:hover {
    background: var(--accent-glow);
    border-color: var(--accent-blue);
    transform: translateY(-2px);
}

/* Contact Links */
.contact-links {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin: 24px 0;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 18px 20px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 14px;
    color: var(--text-primary);
    text-decoration: none;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.contact-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--gradient-secondary);
    opacity: 0;
    transition: opacity 0.3s ease;
    z-index: 0;
}

.contact-item:hover::before {
    opacity: 0.05;
}

.contact-item:hover {
    border-color: var(--accent-blue);
    transform: translateX(4px);
    box-shadow: 0 4px 16px rgba(107, 158, 255, 0.1);
}

.contact-item > * {
    position: relative;
    z-index: 1;
}

.contact-icon {
    font-size: 24px;
}

.contact-info {
    flex: 1;
}

.contact-label {
    font-size: 12px;
    color: var(--text-secondary);
    margin-bottom: 4px;
}

.contact-value {
    font-size: 15px;
    color: var(--text-primary);
}

/* Chat Input Area */
.chat-input-area {
    padding: 16px 24px 24px;
    border-top: 1px solid var(--border-color);
}

.input-container {
    max-width: 900px;
    margin: 0 auto;
    display: flex;
    gap: 12px;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 24px;
    padding: 4px 4px 4px 20px;
}

.chat-input {
    flex: 1;
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 15px;
    padding: 12px 0;
    outline: none;
}

.chat-input::placeholder {
    color: var(--text-secondary);
}

.chat-input:disabled {
    cursor: not-allowed;
}

.send-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 20px;
    cursor: pointer;
    transition: background-color 0.2s;
}

.send-btn:hover:not(:disabled) {
    background-color: var(--bg-hover);
}

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

.disclaimer {
    text-align: center;
    font-size: 12px;
    color: var(--text-secondary);
    margin-top: 12px;
}

/* ===== Scrollbar Styles ===== */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
    background: var(--bg-tertiary);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--bg-hover);
}

/* ===== Mobile Backdrop ===== */
.mobile-backdrop {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 999;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.mobile-backdrop.active {
    display: block;
    opacity: 1;
}

/* ===== Responsive Design ===== */
@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        left: 0;
        top: 0;
        height: 100vh;
        z-index: 1000;
        transform: translateX(-100%);
        box-shadow: 2px 0 8px rgba(0, 0, 0, 0.3);
    }

    .sidebar.active {
        transform: translateX(0);
    }

    /* Show mobile menu button */
    .mobile-menu-btn {
        display: block;
    }

    .chat-header {
        padding: 12px 16px;
    }

    .chat-title {
        font-size: 16px;
        margin-left: 48px;
    }

    .welcome-title {
        font-size: 32px;
    }

    .witty-quote {
        margin: 24px auto 32px;
        padding: 20px 24px;
    }

    .quote-text {
        font-size: 16px;
    }

    .quote-highlight {
        font-size: 18px;
    }

    .quick-actions {
        grid-template-columns: repeat(2, 1fr);
    }

    .chat-messages {
        padding: 16px;
    }

    .message-content {
        margin-left: 0;
    }
}

@media (max-width: 480px) {
    .quick-actions {
        grid-template-columns: 1fr;
    }

    .welcome-title {
        font-size: 28px;
    }
}