/* CSS Variables */
:root {
    --bg-primary: #1a1a1a;
    --bg-secondary: #2a2a2a;
    --bg-tertiary: #333333;
    --bg-input: #2f2f2f;
    --text-primary: #e8e8e8;
    --text-secondary: #a0a0a0;
    --text-muted: #6b6b6b;
    --accent: #d4a853;
    --accent-hover: #e4bc6a;
    --accent-glow: rgba(212, 168, 83, 0.3);
    --border-color: #3a3a3a;
    --border-light: #444444;
    --success: #4ade80;
    --warning: #fbbf24;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-full: 9999px;
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
    --transition-slow: 350ms ease;
}

/* Reset & Base */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
}

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;
    min-height: 100vh;
    min-height: 100dvh;
    overflow: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* App Container */
.app-container {
    height: 100vh;
    height: 100dvh;
    display: flex;
    position: relative;
    overflow: hidden;
}

.app {
    height: 100vh;
    height: 100dvh;
    display: flex;
    flex-direction: column;
    position: relative;
}

/* Sidebar */
.sidebar {
    width: 260px;
    min-width: 260px;
    height: 100%;
    background: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    transition: width var(--transition-normal), min-width var(--transition-normal);
    z-index: 50;
    overflow: hidden;
}

.sidebar.collapsed {
    width: 0;
    min-width: 0;
    border-right: none;
}

.sidebar-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px;
    border-bottom: 1px solid var(--border-color);
}

.new-chat-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 14px;
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    flex: 1;
    margin-right: 8px;
}

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

.new-chat-btn svg {
    color: var(--accent);
}

.sidebar-toggle {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: none;
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.sidebar-toggle:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.sidebar-content {
    flex: 1;
    overflow-y: auto;
    padding: 12px;
}

.conversations-section {
    margin-bottom: 16px;
}

.section-title {
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 8px 8px 12px;
}

.conversations-list {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.conversation-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.875rem;
    cursor: pointer;
    transition: all var(--transition-fast);
    overflow: hidden;
    background: transparent;
    border: none;
    width: 100%;
    text-align: left;
    font-family: inherit;
}

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

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

.conversation-title {
    flex: 1;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.conversation-item .delete-btn {
    opacity: 0;
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: none;
    border-radius: var(--radius-sm);
    color: var(--text-muted);
    cursor: pointer;
    transition: all var(--transition-fast);
    flex-shrink: 0;
}

.conversation-item:hover .delete-btn {
    opacity: 1;
}

.conversation-item .delete-btn:hover {
    background: rgba(239, 68, 68, 0.1);
    color: #ef4444;
}

.sidebar-footer {
    padding: 12px;
    border-top: 1px solid var(--border-color);
    position: relative;
}

.user-profile {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
}

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

.sidebar-footer .user-avatar {
    width: 32px;
    height: 32px;
    font-size: 0.875rem;
}

.user-details {
    flex: 1;
    overflow: hidden;
}

.sidebar-footer .user-name {
    font-size: 0.875rem;
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.user-menu-toggle {
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: none;
    border-radius: var(--radius-sm);
    color: var(--text-muted);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.user-menu-toggle:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.sidebar-footer .user-dropdown {
    position: absolute;
    bottom: 100%;
    left: 12px;
    right: 12px;
    margin-bottom: 8px;
}

/* Main Content */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
    position: relative;
}

/* Menu button - shows when sidebar is collapsed or on mobile */
.menu-btn {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    background: transparent;
    border: 1px solid var(--border-color);
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.menu-btn:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

/* Show menu button when sidebar is collapsed on desktop */
.sidebar.collapsed ~ .main-content .menu-btn {
    display: flex;
}

/* Welcome screen menu button positioning */
.welcome-menu-btn {
    position: absolute;
    top: 16px;
    left: 16px;
}

/* Sidebar overlay for mobile */
.sidebar-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 40;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
}

.sidebar-overlay.visible {
    opacity: 1;
    visibility: visible;
}

/* Empty state for conversations */
.conversations-empty {
    padding: 20px;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.875rem;
}

/* Mobile Responsive */
@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        left: 0;
        top: 0;
        bottom: 0;
        transform: translateX(-100%);
        z-index: 60;
    }

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

    .sidebar.collapsed {
        transform: translateX(-100%);
    }

    .menu-btn {
        display: flex;
    }

    .sidebar-toggle {
        display: none;
    }
}

/* Utility Classes */
.hidden {
    display: none !important;
}

/* Welcome Screen */
.welcome-screen {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 24px;
    animation: fadeIn 0.5s ease;
    position: relative;
}

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

.welcome-content {
    width: 100%;
    max-width: 680px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 32px;
}

/* Greeting */
.greeting {
    display: flex;
    align-items: center;
    gap: 16px;
    font-size: clamp(1.75rem, 5vw, 2.5rem);
    font-weight: 500;
    color: var(--text-primary);
    animation: slideDown 0.6s ease;
}

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

.greeting-icon {
    color: var(--accent);
    font-size: 1.1em;
    animation: gentlePulse 3s ease-in-out infinite;
}

@keyframes gentlePulse {
    0%, 100% {
        opacity: 1;
        transform: scale(1);
    }
    50% {
        opacity: 0.8;
        transform: scale(1.05);
    }
}

/* Input Container */
.input-container {
    width: 100%;
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 16px 20px;
    display: flex;
    align-items: flex-end;
    gap: 12px;
    transition: all var(--transition-normal);
    animation: slideUp 0.6s ease 0.1s both;
}

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

.input-container:focus-within {
    border-color: var(--border-light);
    box-shadow: 0 0 0 1px var(--border-light);
}

.input-container textarea {
    flex: 1;
    background: transparent;
    border: none;
    outline: none;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 1rem;
    line-height: 1.5;
    resize: none;
    min-height: 24px;
    max-height: 200px;
}

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

.input-actions {
    display: flex;
    align-items: center;
    gap: 8px;
}

/* Send Button */
.send-btn {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    background: var(--accent);
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    transition: all var(--transition-fast);
    flex-shrink: 0;
}

.send-btn:hover {
    background: var(--accent-hover);
    transform: translateY(-1px);
}

.send-btn:active {
    transform: translateY(0) scale(0.98);
}

.send-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

/* Suggestions */
.suggestions {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
    animation: slideUp 0.6s ease 0.2s both;
}

.suggestion-chip {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 16px;
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-full);
    color: var(--text-secondary);
    font-family: inherit;
    font-size: 0.875rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.suggestion-chip:hover {
    background: var(--bg-secondary);
    border-color: var(--border-light);
    color: var(--text-primary);
    transform: translateY(-2px);
}

.suggestion-chip:active {
    transform: translateY(0);
}

.suggestion-chip svg {
    opacity: 0.7;
}

/* Disclaimer */
.disclaimer {
    position: absolute;
    bottom: 24px;
    left: 0;
    right: 0;
    margin: 0 auto;
    color: var(--text-muted);
    font-size: 0.75rem;
    text-align: center;
    max-width: 400px;
    padding: 0 24px;
    animation: fadeIn 0.6s ease 0.4s both;
}

/* Chat Screen */
.chat-screen {
    flex: 1;
    display: flex;
    flex-direction: column;
    animation: slideInRight 0.3s ease;
}

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

/* Chat Header */
.chat-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 20px;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 10;
}

.back-btn {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    background: transparent;
    border: 1px solid var(--border-color);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.back-btn:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.chat-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
}

.header-spacer {
    width: 40px;
}

/* Logout Buttons */
.logout-btn {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    background: transparent;
    border: 1px solid var(--border-color);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.logout-btn:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border-color: var(--border-light);
}

.welcome-logout-btn {
    position: absolute;
    top: 16px;
    right: 16px;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    background: transparent;
    border: 1px solid var(--border-color);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

/* User Menu */
.user-menu {
    position: relative;
}

.welcome-screen .user-menu {
    position: absolute;
    top: 16px;
    right: 16px;
}

.user-menu-btn {
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

.user-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--accent);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 1rem;
    text-transform: uppercase;
    transition: all var(--transition-fast);
}

.user-menu-btn:hover .user-avatar {
    background: var(--accent-hover);
    transform: scale(1.05);
}

.user-dropdown {
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    min-width: 220px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    z-index: 100;
    animation: dropdownIn 0.15s ease;
}

@keyframes dropdownIn {
    from {
        opacity: 0;
        transform: translateY(-8px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.user-info {
    padding: 12px 16px;
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.user-name {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.9rem;
}

.user-email {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.dropdown-divider {
    height: 1px;
    background: var(--border-color);
    margin: 4px 0;
}

.dropdown-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 16px;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.875rem;
    transition: all var(--transition-fast);
}

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

.dropdown-item svg {
    opacity: 0.7;
}

.dropdown-item:hover svg {
    opacity: 1;
}

.dropdown-item-danger {
    color: #ef4444;
}

.dropdown-item-danger:hover {
    background: rgba(239, 68, 68, 0.1);
    color: #ef4444;
}

/* Login Prompt Popover */
.login-prompt {
    position: fixed;
    bottom: 100px;
    left: 50%;
    transform: translateX(-50%) translateY(20px);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    padding: 20px 24px;
    z-index: 200;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
}

.login-prompt.visible {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

.login-prompt-content {
    display: flex;
    align-items: center;
    gap: 16px;
}

.login-prompt-content p {
    margin: 0;
    color: var(--text-primary);
    font-size: 0.95rem;
}

.login-prompt-btn {
    background: var(--accent);
    color: white;
    padding: 10px 20px;
    border-radius: var(--radius-sm);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9rem;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.login-prompt-btn:hover {
    background: var(--accent-hover);
}

.login-prompt-close {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0;
    line-height: 1;
    margin-left: 8px;
}

.login-prompt-close:hover {
    color: var(--text-primary);
}

/* Chat Messages */
.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 20px;
    scroll-behavior: smooth;
}

.message {
    max-width: 85%;
    animation: messageIn 0.3s ease;
}

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

.message.user {
    align-self: flex-end;
}

.message.assistant {
    align-self: flex-start;
}

.message-content {
    padding: 14px 18px;
    border-radius: var(--radius-lg);
    line-height: 1.6;
    white-space: pre-wrap;
    word-wrap: break-word;
}

.message.user .message-content {
    background: var(--accent);
    color: white;
    border-bottom-right-radius: var(--radius-sm);
}

.message.assistant .message-content {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border-bottom-left-radius: var(--radius-sm);
}

.message-meta {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-top: 6px;
    padding: 0 4px;
}

.message.user .message-meta {
    justify-content: flex-end;
}

.message-time {
    font-size: 0.7rem;
    color: var(--text-muted);
}

/* Streaming cursor */
.message-content.streaming .cursor {
    display: inline-block;
    width: 2px;
    height: 1.1em;
    background: var(--accent);
    margin-left: 2px;
    vertical-align: text-bottom;
    animation: blink 0.7s infinite;
}

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

/* Referral Notice */
.referral-notice {
    display: flex;
    align-items: center;
    gap: 12px;
    margin: 0 20px 16px;
    padding: 14px 18px;
    background: rgba(251, 191, 36, 0.1);
    border: 1px solid rgba(251, 191, 36, 0.3);
    border-radius: var(--radius-md);
    animation: slideUp 0.3s ease;
}

.referral-icon {
    font-size: 1.25rem;
}

.referral-notice p {
    font-size: 0.875rem;
    color: var(--warning);
    line-height: 1.5;
}

/* Chat Input Area */
.chat-input-area {
    padding: 16px 20px;
    background: var(--bg-primary);
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: center;
}

.chat-input-container {
    display: flex;
    align-items: flex-end;
    gap: 12px;
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 12px 16px;
    transition: all var(--transition-normal);
    width: 100%;
    max-width: 680px;
}

.chat-input-container:focus-within {
    border-color: var(--border-light);
}

.chat-input-container textarea {
    flex: 1;
    background: transparent;
    border: none;
    outline: none;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 1rem;
    line-height: 1.5;
    resize: none;
    min-height: 24px;
    max-height: 150px;
}

.chat-input-container textarea::placeholder {
    color: var(--text-muted);
}

/* Loading Indicator */
.loading-indicator {
    position: fixed;
    bottom: 100px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--bg-secondary);
    padding: 12px 20px;
    border-radius: var(--radius-full);
    box-shadow: var(--shadow-md);
    z-index: 100;
}

.loading-dots {
    display: flex;
    gap: 6px;
}

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

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

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

@keyframes loadingBounce {
    0%, 80%, 100% {
        transform: scale(0.6);
        opacity: 0.5;
    }
    40% {
        transform: scale(1);
        opacity: 1;
    }
}

/* Typing Indicator in Messages */
.typing-indicator {
    padding: 16px 20px;
}

.thinking-phase {
    display: flex;
    align-items: center;
    gap: 12px;
}

.phase-text {
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-style: italic;
    transition: opacity 0.15s ease;
}

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

.phase-dots span {
    width: 6px;
    height: 6px;
    background: var(--accent);
    border-radius: 50%;
    animation: typingBounce 1.4s ease-in-out infinite both;
}

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

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

@keyframes typingBounce {
    0%, 80%, 100% {
        transform: translateY(0);
    }
    40% {
        transform: translateY(-4px);
    }
}

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

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

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

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

/* Mobile Responsive */
@media (max-width: 640px) {
    .welcome-screen {
        padding: 20px 16px;
    }

    .greeting {
        font-size: 1.5rem;
    }

    .input-container {
        padding: 12px 16px;
    }

    .suggestions {
        gap: 8px;
    }

    .suggestion-chip {
        padding: 8px 14px;
        font-size: 0.8rem;
    }

    .disclaimer {
        font-size: 0.7rem;
        padding: 0 16px;
    }

    .chat-messages {
        padding: 16px;
    }

    .message {
        max-width: 90%;
    }

    .message-content {
        padding: 12px 14px;
        font-size: 0.95rem;
    }
}

/* Safe Area Padding for iOS */
@supports (padding-bottom: env(safe-area-inset-bottom)) {
    .chat-input-area {
        padding-bottom: calc(16px + env(safe-area-inset-bottom));
    }

    .disclaimer {
        bottom: calc(24px + env(safe-area-inset-bottom));
    }
}

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

/* Selection Color */
::selection {
    background: var(--accent);
    color: white;
}