:root {
    --bg-primary: #0a0a0c;
    --bg-secondary: #16161a;
    --bg-accent: #1e1e24;
    --text-primary: #f0f0f5;
    --text-secondary: #a0a0ab;
    --accent-color: #6366f1;
    --accent-glow: rgba(99, 102, 241, 0.3);
    --border-color: #2e2e38;
    --error-color: #ef4444;
    --success-color: #22c55e;
    --glass-bg: rgba(22, 22, 26, 0.8);
    --font-main: 'Outfit', sans-serif;
    --transition-speed: 0.3s;
}

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

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: var(--font-main);
    height: 100vh;
    height: 100dvh;
    display: flex;
    overflow: hidden;
}

/* Sidebar Styling */
.sidebar {
    width: 300px;
    background-color: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    padding: 1.5rem;
    transition: width var(--transition-speed);
}

.sidebar-header {
    margin-bottom: 2rem;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, #6366f1, #a855f7);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -1px;
}

.new-chat-btn {
    background-color: var(--accent-color);
    color: white;
    border: none;
    padding: 0.8rem 1rem;
    border-radius: 12px;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: all var(--transition-speed);
    box-shadow: 0 4px 12px var(--accent-glow);
    margin-bottom: 1.5rem;
}

.new-chat-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px var(--accent-glow);
    background-color: #4f46e5;
}

.conv-list {
    flex: 1;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.conv-item {
    padding: 0.75rem 1rem;
    border-radius: 10px;
    cursor: pointer;
    transition: background var(--transition-speed);
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

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

.conv-item.active {
    background-color: var(--bg-accent);
    border: 1px solid var(--accent-color);
}

.conv-title {
    font-size: 0.9rem;
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.conv-meta {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.conv-actions {
    display: flex;
    gap: 2px;
    opacity: 0;
    transition: opacity var(--transition-speed);
}

.conv-item:hover .conv-actions {
    opacity: 1;
}

.rename-conv-btn,
.delete-conv-btn {
    padding: 2px 5px !important;
    font-size: 0.8rem !important;
}

.rename-conv-btn:hover {
    color: var(--accent-color) !important;
    background-color: rgba(99, 102, 241, 0.1) !important;
}

.delete-conv-btn:hover {
    color: var(--error-color) !important;
    background-color: rgba(239, 68, 68, 0.1) !important;
}

/* Main Content Area */
.main-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    position: relative;
    background: radial-gradient(circle at top right, #16161a 0%, #0a0a0c 100%);
}

.header {
    height: 60px;
    padding: 0 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid var(--border-color);
    backdrop-filter: blur(10px);
    background-color: var(--glass-bg);
}

.model-selector-container {
    display: flex;
    align-items: center;
    gap: 1rem;
}

select {
    background-color: var(--bg-accent);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    padding: 0.5rem 1rem;
    border-radius: 8px;
    outline: none;
    cursor: pointer;
    font-family: inherit;
}

.tab-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    padding: 0.5rem 1rem;
    cursor: pointer;
    font-weight: 600;
    border-bottom: 2px solid transparent;
}

.tab-btn.active {
    color: var(--accent-color);
    border-bottom-color: var(--accent-color);
}

.system-prompt-badge {
    background: var(--accent-color);
    color: white;
    font-size: 0.7rem;
    padding: 0.1rem 0.4rem;
    border-radius: 4px;
    margin-left: 0.5rem;
}

/* Chat Area */
.chat-window {
    flex: 1;
    overflow-y: auto;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    scroll-behavior: smooth;
}

.message {
    max-width: 80%;
    padding: 1.25rem;
    border-radius: 16px;
    line-height: 1.6;
    font-size: 0.95rem;
    position: relative;
    animation: fadeIn 0.4s ease-out;
}

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

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.message.user {
    align-self: flex-end;
    background-color: var(--accent-color);
    color: white;
    border-bottom-right-radius: 4px;
}

.message.assistant {
    align-self: flex-start;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-bottom-left-radius: 4px;
}

/* Input Area */
.input-container {
    padding: 1.5rem 2rem;
    background-color: transparent;
}

.input-box-wrapper {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 0.75rem 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
    transition: border-color var(--transition-speed);
}

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

textarea {
    background: transparent;
    border: none;
    color: var(--text-primary);
    resize: none;
    outline: none;
    font-family: inherit;
    font-size: 1rem;
    width: 100%;
    min-height: 40px;
    max-height: 200px;
}

.input-actions {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.action-btns {
    display: flex;
    gap: 0.5rem;
}

.icon-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 8px;
    transition: all var(--transition-speed);
}

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

.send-btn {
    background-color: var(--accent-color);
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 10px;
    cursor: pointer;
    font-weight: 600;
}

/* Comparison Mode Layout */
.comparison-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1px;
    background-color: var(--border-color);
    flex: 1;
    overflow: hidden;
}

.comparison-pane {
    display: flex;
    flex-direction: column;
    background-color: var(--bg-primary);
    overflow: hidden;
}

/* Modals */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    z-index: 100;
    display: none;
    /* Default to hidden */
    align-items: center;
    justify-content: center;
}

.modal.active {
    display: flex;
}

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

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 6px;
}

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

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 10px;
}

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

/* Attachment Preview */
.attachment-preview {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 0.5rem;
}

.attachment-item {
    position: relative;
    background: var(--bg-accent);
    padding: 0.4rem 0.8rem;
    border-radius: 8px;
    font-size: 0.8rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    border: 1px solid var(--border-color);
}

/* Code Blocks & Syntax Highlighting */
.code-block-wrapper {
    margin: 1rem 0;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background: #0d1117;
    /* GitHub Dark BG */
    overflow: hidden;
}

.code-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem 1rem;
    background: var(--bg-accent);
    border-bottom: 1px solid var(--border-color);
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.copy-btn {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 0.2rem 0.6rem;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.75rem;
    transition: all 0.2s;
}

.copy-btn:hover {
    background: var(--bg-secondary);
    color: white;
    border-color: var(--text-secondary);
}

/* Stop Button */
.stop-btn {
    background-color: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--error-color);
    padding: 0.5rem 1rem;
    border-radius: 10px;
    cursor: pointer;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: all var(--transition-speed);
}

.stop-btn:hover {
    background-color: rgba(239, 68, 68, 0.1);
    color: var(--error-color);
}

/* Adjust pre/code from markdown to fit wrapper */
.code-block-wrapper pre {
    margin: 0;
    padding: 1rem;
    overflow-x: auto;
}

.code-block-wrapper code {
    background: transparent !important;
    padding: 0 !important;
}

.attachment-item.image-item {
    padding: 0;
    overflow: hidden;
    width: 60px;
    height: 60px;
}

.attachment-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.remove-attachment {
    position: absolute;
    top: -5px;
    right: -5px;
    background: var(--error-color);
    color: white;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.7rem;
    cursor: pointer;
    border: 1px solid var(--bg-secondary);
    z-index: 2;
}

/* Chat Images */
.message-images {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.message-images img {
    max-width: 200px;
    max-height: 200px;
    border-radius: 8px;
    cursor: zoom-in;
    border: 1px solid var(--border-color);
}

/* Login Page Styles */
.login-page {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    min-height: 100dvh;
    background: linear-gradient(135deg, #0a0a0c 0%, #16161a 50%, #1e1e24 100%);
    position: relative;
    overflow: hidden;
}

.login-page::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at 30% 30%, rgba(99, 102, 241, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 70% 70%, rgba(168, 85, 247, 0.08) 0%, transparent 50%);
    animation: gradientShift 15s ease-in-out infinite;
}

@keyframes gradientShift {

    0%,
    100% {
        transform: translate(0, 0) rotate(0deg);
    }

    50% {
        transform: translate(-5%, -5%) rotate(5deg);
    }
}

.login-container {
    position: relative;
    z-index: 1;
    width: 100%;
    max-width: 420px;
    padding: 1.5rem;
}

.login-card {
    background: rgba(22, 22, 26, 0.85);
    backdrop-filter: blur(20px);
    border: 1px solid var(--border-color);
    border-radius: 24px;
    padding: 3rem 2.5rem;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5),
        0 0 0 1px rgba(255, 255, 255, 0.05) inset;
}

.login-header {
    text-align: center;
    margin-bottom: 2.5rem;
}

.login-header .logo {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.login-subtitle {
    color: var(--text-secondary);
    font-size: 1rem;
    font-weight: 400;
}

.flash-message {
    padding: 0.875rem 1rem;
    border-radius: 10px;
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
    font-weight: 500;
}

.flash-message.error {
    background: rgba(239, 68, 68, 0.15);
    border: 1px solid rgba(239, 68, 68, 0.3);
    color: #fca5a5;
}

.login-form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.form-group input {
    background: var(--bg-accent);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 0.875rem 1rem;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 1rem;
    transition: all var(--transition-speed);
}

.form-group input:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.form-group input::placeholder {
    color: var(--text-secondary);
    opacity: 0.6;
}

.login-btn {
    background: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
    color: white;
    border: none;
    padding: 1rem;
    border-radius: 12px;
    font-family: inherit;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-speed);
    box-shadow: 0 4px 15px var(--accent-glow);
    margin-top: 0.5rem;
}

.login-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px var(--accent-glow);
}

.login-btn:active {
    transform: translateY(0);
}

/* ============================================
   MOBILE RESPONSIVE STYLES
   Mimics ChatGPT/Gemini mobile patterns
   ============================================ */

/* Hamburger Menu Button */
.hamburger-btn {
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 5px;
    width: 40px;
    height: 40px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 8px;
    border-radius: 8px;
    transition: background var(--transition-speed);
}

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

.hamburger-btn span {
    display: block;
    width: 20px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all var(--transition-speed);
}

/* Sidebar Close Button (mobile only) */
.sidebar-close-btn {
    display: none;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 1.2rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 8px;
    transition: all var(--transition-speed);
}

.sidebar-close-btn:hover {
    background: var(--bg-accent);
    color: var(--text-primary);
}

/* Sidebar Overlay */
.sidebar-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
    z-index: 90;
    opacity: 0;
    transition: opacity var(--transition-speed);
}

.sidebar-overlay.active {
    display: block;
    opacity: 1;
}

/* Message Stats */
.message-stats {
    display: flex;
    gap: 1rem;
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-top: 0.75rem;
    padding-top: 0.5rem;
    border-top: 1px solid var(--border-color);
}

/* Total Tokens Display */
.total-tokens {
    background: var(--bg-accent);
    padding: 0.4rem 0.8rem;
    border-radius: 8px;
    font-size: 0.8rem;
    color: var(--text-secondary);
    white-space: nowrap;
}

/* ============================================
   TABLET BREAKPOINT (768px - 1024px)
   ============================================ */
@media (max-width: 1024px) {
    .sidebar {
        width: 260px;
    }

    .header {
        padding: 0 1.5rem;
    }

    .chat-window {
        padding: 1.5rem;
    }

    .input-container {
        padding: 1rem 1.5rem;
    }

    .message {
        max-width: 85%;
    }
}

/* ============================================
   MOBILE BREAKPOINT (max-width: 768px)
   ============================================ */
@media (max-width: 768px) {

    /* Show hamburger and mobile controls */
    .hamburger-btn {
        display: flex;
    }

    .sidebar-close-btn {
        display: block;
    }

    /* Sidebar Header Layout */
    .sidebar-header {
        display: flex;
        justify-content: space-between;
        align-items: center;
    }

    /* Sidebar as overlay drawer */
    .sidebar {
        position: fixed;
        left: 0;
        top: 0;
        height: 100%;
        width: 280px;
        z-index: 100;
        transform: translateX(-100%);
        transition: transform var(--transition-speed) ease;
        box-shadow: none;
    }

    .sidebar.open {
        transform: translateX(0);
        box-shadow: 4px 0 20px rgba(0, 0, 0, 0.5);
    }

    /* Main container takes full width */
    .main-container {
        width: 100%;
    }

    /* Header adjustments */
    .header {
        padding: 0 1rem;
        gap: 0.5rem;
    }

    .model-selector-container {
        flex: 1;
        justify-content: flex-end;
        gap: 0.5rem;
        overflow-x: auto;
    }

    .model-selector-container select {
        font-size: 0.85rem;
        padding: 0.4rem 0.6rem;
        max-width: 120px;
    }

    .total-tokens {
        font-size: 0.7rem;
        padding: 0.3rem 0.5rem;
    }

    /* Chat Window */
    .chat-window {
        padding: 1rem;
        gap: 1rem;
    }

    /* Messages */
    .message {
        max-width: 90%;
        padding: 1rem;
        font-size: 0.9rem;
    }

    .message.user {
        max-width: 85%;
    }

    /* Input Area */
    .input-container {
        padding: 0.75rem 1rem;
        padding-bottom: calc(1.25rem + env(safe-area-inset-bottom, 0));
    }

    .input-box-wrapper {
        border-radius: 12px;
        padding: 0.5rem 0.75rem;
    }

    textarea {
        font-size: 16px;
        /* Prevents iOS zoom on focus */
        min-height: 36px;
    }

    .send-btn,
    .stop-btn {
        padding: 0.5rem 0.75rem;
        font-size: 0.9rem;
    }

    .icon-btn {
        padding: 0.6rem;
        font-size: 1.1rem;
    }

    /* Welcome Screen */
    .welcome-screen h2 {
        font-size: 1.75rem !important;
    }

    .welcome-screen p {
        font-size: 0.9rem;
    }

    /* Code blocks */
    .code-block-wrapper {
        margin: 0.75rem 0;
    }

    .code-block-wrapper pre {
        padding: 0.75rem;
        font-size: 0.8rem;
    }

    .code-header {
        padding: 0.4rem 0.75rem;
        font-size: 0.7rem;
    }

    /* Message Images */
    .message-images img {
        max-width: 150px;
        max-height: 150px;
    }

    /* Attachment Preview */
    .attachment-item {
        padding: 0.3rem 0.6rem;
        font-size: 0.75rem;
    }

    .attachment-item.image-item {
        width: 50px;
        height: 50px;
    }

    /* Modal adjustments */
    .modal-content {
        width: 95% !important;
        max-width: 400px !important;
        padding: 1.5rem !important;
        margin: 1rem;
        border-radius: 16px !important;
    }

    #prompt-content {
        min-height: 150px !important;
    }
}

/* ============================================
   SMALL MOBILE BREAKPOINT (max-width: 480px)
   ============================================ */
@media (max-width: 480px) {
    .sidebar {
        width: 100%;
    }

    .header {
        height: 56px;
        padding: 0 0.75rem;
    }

    .hamburger-btn {
        width: 36px;
        height: 36px;
    }

    .model-selector-container select {
        max-width: 100px;
        font-size: 0.8rem;
    }

    .chat-window {
        padding: 0.75rem;
    }

    .message {
        max-width: 95%;
        padding: 0.875rem;
        border-radius: 12px;
        font-size: 0.875rem;
    }

    .input-container {
        padding: 0.5rem 0.75rem;
        padding-bottom: calc(0.5rem + env(safe-area-inset-bottom, 0));
    }

    .input-box-wrapper {
        padding: 0.4rem 0.6rem;
    }

    .send-btn,
    .stop-btn {
        padding: 0.4rem 0.6rem;
        font-size: 0.85rem;
        border-radius: 8px;
    }

    .new-chat-btn {
        padding: 0.7rem 0.9rem;
        font-size: 0.9rem;
    }

    .conv-item {
        padding: 0.6rem 0.8rem;
    }

    .conv-title {
        font-size: 0.85rem;
    }

    .conv-meta {
        font-size: 0.7rem;
    }

    .logo {
        font-size: 1.25rem;
    }

    /* Welcome screen compact */
    .welcome-screen {
        padding: 0 1rem;
    }

    .welcome-screen h2 {
        font-size: 1.5rem !important;
    }
}

/* ============================================
   LANDSCAPE ORIENTATION FIXES
   ============================================ */
@media (max-height: 500px) and (orientation: landscape) {
    .header {
        height: 48px;
    }

    .chat-window {
        padding: 0.5rem 1rem;
        gap: 0.75rem;
    }

    .message {
        padding: 0.75rem;
    }

    .input-container {
        padding: 0.5rem 1rem;
    }

    .sidebar {
        padding: 1rem;
    }

    .new-chat-btn {
        padding: 0.6rem 0.8rem;
        margin-bottom: 1rem;
    }
}

/* ============================================
   TOUCH DEVICE OPTIMIZATIONS
   ============================================ */
@media (hover: none) and (pointer: coarse) {

    /* Larger touch targets */
    .icon-btn {
        min-width: 44px;
        min-height: 44px;
    }

    .send-btn,
    .stop-btn {
        min-height: 40px;
    }

    .conv-item {
        min-height: 60px;
    }

    /* Always show conversation actions on touch */
    .conv-actions {
        opacity: 1;
    }

    /* Remove hover effects that don't work on touch */
    .new-chat-btn:hover {
        transform: none;
    }

    .login-btn:hover {
        transform: none;
    }
}

/* ============================================
   SAFE AREA INSETS (iPhone notch, etc.)
   ============================================ */
@supports (padding: max(0px)) {
    .sidebar {
        padding-left: max(1.5rem, env(safe-area-inset-left));
        padding-right: max(1.5rem, env(safe-area-inset-right));
    }

    .header {
        padding-left: max(1rem, env(safe-area-inset-left));
        padding-right: max(1rem, env(safe-area-inset-right));
    }

    .input-container {
        padding-left: max(1rem, env(safe-area-inset-left));
        padding-right: max(1rem, env(safe-area-inset-right));
        padding-bottom: max(0.75rem, env(safe-area-inset-bottom));
    }
}