/* ==========  CHATGPT-LEVEL UI  ========== */

:root {
    --bg-primary: #0d1117;
    --bg-secondary: #161b22;
    --bg-tertiary: #21262d;
    --border: #2a3138;
    --text-primary: #d6dde6;
    --text-secondary: #9aa3ad;
    --accent: #ff8b3e;
    --accent-hover: #ff7a1a;
    --success: #3fb950;
    --error: #f85149;
    --warning: #d29922;
    --font-size-base: 16px;
    font-size: var(--font-size-base);
}

/* Light mode variables */
[data-theme="light"] {
    --bg-primary: #2d2b29;
    --bg-secondary: #74716e;
    --bg-tertiary: rgba(255, 128, 0, 0.08);
    --border: #040404;
    --text-primary: #000000;
    --text-secondary: rgba(0, 0, 0, 0.78);
    --accent: #0d1117;
    --accent-hover: #ff7a1a;
    --success: #2aa360;
    --error: #c23c3c;
    --warning: #c0772b;
}

[data-theme="light"] .conversation-item:hover { background: rgba(255, 245, 235, 0.12); }
[data-theme="light"] tr:nth-child(even) { background: rgba(255, 245, 235, 0.06); }
[data-theme="light"] .modal-content { box-shadow: 0 12px 24px rgba(0,0,0,0.18); }
[data-theme="light"] .thinking-animation i { color: var(--accent); }
[data-theme="light"] .action-btn:hover { background: rgba(255, 245, 235, 0.12); color: var(--text-primary); }
[data-theme="light"] .message-content { box-shadow: 0 6px 14px rgba(0,0,0,0.18); }
[data-theme="light"] .chat-form { box-shadow: 0 4px 12px rgba(0,0,0,0.14); }
[data-theme="light"] pre { background: rgba(255, 245, 235, 0.12); color: var(--text-primary); border-color: var(--border); }
[data-theme="light"] code { background: rgba(255, 245, 235, 0.12); }

[data-theme="dark"] .conversation-item:hover { background: rgba(255,255,255,0.04); }
[data-theme="dark"] tr:nth-child(even) { background: rgba(255,255,255,0.02); }
[data-theme="dark"] .modal-content { box-shadow: 0 10px 22px rgba(0,0,0,0.45); }
[data-theme="dark"] .message-content { box-shadow: 0 6px 12px rgba(0,0,0,0.35); }
[data-theme="dark"] .chat-form { box-shadow: 0 4px 10px rgba(0,0,0,0.3); }
[data-theme="dark"] pre { background: #0b0f14; color: var(--text-primary); border-color: var(--border); }
[data-theme="dark"] code { background: rgba(255,255,255,0.06); }

/* Reset box-sizing globally */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
/* Hide AI reasoning from chat messages */
.reasoning-content {
    display: none !important;
}

/* Ensure only proper messages are visible */
.message:has(.reasoning-content) {
    display: none !important;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji";
    background: var(--bg-primary);
    color: var(--text-primary);
    overflow-x: hidden;
    width: 100%;
    -webkit-text-size-adjust: 100%;
    -ms-text-size-adjust: 100%;
}

/* ---- File Upload Styles ---- */
.file-preview {
    margin-bottom: 12px;
    animation: fadeIn 0.3s ease;
}

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

.image-preview {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 12px;
    margin-bottom: 12px;
    max-width: 400px;
}

.image-preview-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 8px;
    font-size: 0.9em;
    color: var(--text-secondary);
}

.image-preview-footer {
    margin-top: 8px;
    font-size: 0.8em;
    color: var(--accent);
    text-align: center;
}

.action-btn.small {
    padding: 2px 6px;
    font-size: 0.7em;
    min-width: auto;
}

/* Vision mode indicator */
#visionToggle.active {
    background: var(--accent) !important;
    color: white !important;
}

/* File upload button */
#fileUploadBtn {
    transition: all 0.2s ease;
}

#fileUploadBtn:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

/* Mobile adjustments for file upload */
@media (max-width: 768px) {
    .image-preview {
        max-width: 100%;
    }
    
    .image-preview img {
        max-width: 250px !important;
        max-height: 150px !important;
    }
}

@media (max-width: 480px) {
    .image-preview img {
        max-width: 200px !important;
        max-height: 120px !important;
    }
}

.app-container {
    display: flex;
    height: 100vh;
    width: 100%;
    max-width: 100%;
    overflow-x: hidden;
}

/* ---- SIDEBAR OVERLAY ---- */
.sidebar-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease;
}
.sidebar-overlay.active {
    opacity: 1;
    visibility: visible;
}

/* ---- SIDEBAR ---- */
.sidebar {
    width: 260px;
    background: var(--bg-secondary);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    transition: .2s;
}

.sidebar-header,
.sidebar-footer {
    padding: 16px;
}

.sidebar-header {
    position: relative;
}

.sidebar-close-btn {
    position: absolute;
    top: 16px;
    right: 16px;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 18px;
    cursor: pointer;
    padding: 8px;
    border-radius: 4px;
    transition: all 0.2s;
    display: none;
}

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

.sidebar-header {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.sidebar-close-btn {
    display: none;
    position: absolute;
    top: 16px;
    right: 16px;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 1.2rem;
    cursor: pointer;
    padding: 8px;
    border-radius: 4px;
    transition: all 0.2s;
}

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

.new-chat-btn,
.reload-kb-btn,
.export-conv-btn,
.about {
    width: 100%;
    padding: 10px 12px;
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border);
    border-radius: 6px;
    cursor: pointer;
    transition: .2s;
    margin-bottom: 8px;
}
.new-chat-btn:hover,
.reload-kb-btn:hover,
.export-conv-btn:hover,
.about:hover {
    background: var(--bg-tertiary);
}

.conversations-section {
    flex: 1;
    overflow-y: auto;
    padding: 8px;
}

.search-conversations {
    position: relative;
    margin-bottom: 12px;
}

.search-input {
    width: 100%;
    padding: 8px 12px 8px 32px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text-primary);
    font-size: 13px;
    outline: none;
    transition: border-color 0.2s;
}

.search-input:focus {
    border-color: var(--accent);
}

.search-icon {
    position: absolute;
    left: 10px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
    font-size: 12px;
}

.section-title {
    padding: 8px 12px;
    font-size: 11px;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: .05em;
}

.search-conversations {
    position: relative;
    margin-bottom: 12px;
    padding: 0 12px;
}

.search-input {
    width: 100%;
    padding: 8px 12px 8px 36px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text-primary);
    font-size: 14px;
    outline: none;
    transition: border-color 0.2s;
}

.search-input:focus {
    border-color: var(--accent);
}

.search-icon {
    position: absolute;
    left: 20px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
    font-size: 12px;
}

.category-filter {
    margin-bottom: 12px;
    padding: 0 12px;
}

.category-select {
    width: 100%;
    padding: 8px 12px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text-primary);
    font-size: 14px;
    outline: none;
    cursor: pointer;
    transition: border-color 0.2s;
}

.category-select:focus {
    border-color: var(--accent);
}

.conversation-item {
    padding: 10px 12px;
    margin: 2px 0;
    border-radius: 6px;
    cursor: pointer;
    position: relative;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.conversation-title {
    font-weight: 500;
    font-size: 14px;
    margin-bottom: 2px;
}
.conversation-preview {
    font-size: 12px;
    color: var(--text-secondary);
    margin-bottom: 4px;
}
.conversation-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 4px;
}

.conversation-category {
    font-size: 10px;
    color: var(--accent);
    background: var(--bg-tertiary);
    padding: 2px 6px;
    border-radius: 10px;
    text-transform: uppercase;
    font-weight: 500;
}

.conversation-time {
    font-size: 11px;
    color: var(--text-secondary);
    opacity: 0.8;
}

.conversation-actions {
    position: absolute;
    right: 8px;
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    gap: 4px;
    opacity: 0;
    transition: opacity 0.2s;
}

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

.share-conversation,
.delete-conversation {
    background: transparent;
    border: none;
    color: inherit;
    cursor: pointer;
    padding: 4px;
    border-radius: 3px;
    font-size: 12px;
    transition: background 0.2s;
}

.share-conversation:hover {
    background: var(--accent);
    color: white;
}

.delete-conversation:hover {
    background: var(--error);
    color: white;
}
.conversation-item:hover {
    background: var(--bg-tertiary);
}
.conversation-item.active {
    background: var(--accent);
    color: #fff;
}

.conversation-actions {
    position: absolute;
    right: 8px;
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    gap: 4px;
    opacity: 0;
    transition: .2s;
}

.conversation-item:hover .conversation-actions {
    opacity: .7;
}

.share-conversation,
.delete-conversation {
    background: transparent;
    border: none;
    color: inherit;
    cursor: pointer;
    padding: 4px;
    border-radius: 3px;
    transition: .2s;
}

.share-conversation:hover {
    background: var(--accent);
    color: white;
}

.delete-conversation:hover {
    background: var(--error);
    color: white;
}

/* ---- MAIN CHAT ---- */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    width: 100%;
    max-width: 100%;
}

.chat-header {
    padding: 12px 16px;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: var(--bg-secondary);
    font-weight: 600;
    font-size: 1.05rem;
    width: 100%;
    max-width: 100%;
    gap: 12px;
    position: sticky;
    top: 0;
    z-index: 100;
    min-height: 60px;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
    justify-content: flex-end;
    max-width: 100%;
}

.theme-toggle-btn {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-secondary);
    border-radius: 6px;
    padding: 8px 12px;
    cursor: pointer;
    transition: all 0.2s;
    font-size: 1rem;
}

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

.settings-btn {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-secondary);
    border-radius: 6px;
    padding: 8px 12px;
    cursor: pointer;
    transition: all 0.2s;
    font-size: 1rem;
}

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

.model-selector {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-secondary);
    border-radius: 6px;
    padding: 8px 12px;
    cursor: pointer;
    transition: all 0.2s;
    font-size: 14px;
    outline: none;
    min-width: 100px;
    max-width: 100px;
}

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

.model-selector:focus {
    border-color: var(--accent);
    color: var(--text-primary);
}

.mobile-menu-btn {
    display: none;
    background: transparent;
    border: none;
    color: var(--text-primary);
    font-size: 1.3rem;
    cursor: pointer;
}

.online-status {
    font-size: 12px;
    padding: 4px 8px;
    border-radius: 12px;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.online-status.online {
    background: var(--success);
    color: white;
}

.online-status.offline {
    background: var(--error);
    color: white;
}

.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 24px;
    width: 100%;
}

.message {
    display: flex;
    gap: 16px;
    margin-bottom: 24px;
    max-width: 100%;
    width: 100%;
}

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

.message-avatar {
    width: 30px;
    height: 30px;
    border-radius: 4px;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    font-weight: 600;
}
.message.user .message-avatar {
    background: var(--accent);
    color: #fff;
}
.message.bot .message-avatar {
    background: #10a37f;
    color: #fff;
}

.message-content-wrapper {
    flex: 1;
    position: relative;
    max-width: 100%;
}

.message-content {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 12px 16px;
    line-height: 1.5;
    white-space: pre-wrap;
    word-break: break-word;
    overflow-wrap: break-word;
    max-width: 100%;
    width: 100%;
}

.message.user .message-content {
    background: var(--bg-tertiary);
}

.message-timestamp {
    margin-top: 6px;
    font-size: 11px;
    color: var(--text-secondary);
    opacity: 0.9;
}

.message.user .message-timestamp {
    text-align: right;
}

.message.bot .message-timestamp {
    text-align: left;
}

/* ---- CODE BLOCKS ---- */
pre {
    background: #010409;
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 16px;
    overflow-x: auto;
    margin: 8px 0;
    font-size: 13px;
    line-height: 1.45;
}

code {
    font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, Courier, monospace;
    background: var(--bg-tertiary);
    padding: .15em .4em;
    border-radius: 4px;
    font-size: 90%;
}

pre code {
    background: none;
    padding: 0;
}

/* ---- MESSAGE ACTIONS ---- */
.message-actions {
    display: flex;
    gap: 8px;
    margin-top: 8px;
    opacity: 0;
    transition: opacity .2s;
    justify-content: flex-end;
    width: 100%;
}
.message:hover .message-actions {
    opacity: 1;
}

.action-btn {
    background: transparent;
    border: 2px double var(--border);
    color: var(--text-secondary);
    border-radius: 4px;
    padding: 4px 8px;
    font-size: .75rem;
    cursor: pointer;
}
.action-btn:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

/* ---- THINKING ANIMATION ---- */
.thinking-animation {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 8px;
}
.thinking-animation i {
    font-size: 20px;
    color: var(--accent);
}
.thinking-labels {
    text-align: center;
    font-size: 12px;
    color: var(--text-secondary);
    font-weight: 500;
}

/* ---- CHAT INPUT ---- */
.chat-input-container {
    padding: 24px;
    background: var(--bg-primary);
    border-top: 1px solid var(--border);
    width: 100%;
}

.chat-input-wrapper {
    max-width: 100%;
    width: 100%;
    margin: 0 auto;
}

.chat-form {
    display: flex;
    align-items: flex-end;
    gap: 12px;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 8px 12px;
    transition: border .2s;
    width: 100%;
}
.chat-form:focus-within {
    border-color: var(--accent);
}

.message-input {
    flex: 1;
    background: transparent;
    border: none;
    outline: none;
    color: var(--text-primary);
    resize: none;
    max-height: 150px;
    line-height: 1.5;
    font-size: 14px;
    width: 100%;
}

.send-button {
    width: 32px;
    height: 32px;
    background: var(--accent);
    color: #fff;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: .2s;
    flex-shrink: 0;
}
.send-button:hover:not(:disabled) {
    background: var(--accent-hover);
}
.send-button:disabled {
    background: var(--border);
    cursor: not-allowed;
}

/* ---- EDIT MODE ---- */
.edit-mode {
    border: 2px solid var(--accent);
    border-radius: 8px;
    background: var(--bg-primary);
    padding: 12px;
    box-shadow: 0 2px 8px rgba(88, 166, 255, 0.1);
}
.edit-textarea {
    width: 100%;
    background: transparent;
    border: none;
    outline: none;
    color: var(--text-primary);
    resize: none;
    min-height: 80px;
    max-height: 200px;
    font-family: inherit;
    font-size: inherit;
    line-height: 1.5;
    padding: 8px;
    border-radius: 4px;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
}
.edit-textarea:focus {
    border-color: var(--accent);
}
.edit-actions {
    display: flex;
    gap: 8px;
    margin-top: 12px;
    justify-content: flex-end;
}
.edit-actions .action-btn {
    padding: 8px 16px;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 6px;
}
.save-edit-btn {
    background: var(--success) !important;
    color: white !important;
    border-color: var(--success) !important;
}
.save-edit-btn:hover {
    background: #2ea043 !important;
}
.cancel-edit-btn {
    background: var(--error) !important;
    color: white !important;
    border-color: var(--error) !important;
}
.cancel-edit-btn:hover {
    background: #da3633 !important;
}

/* ---- WELCOME SCREEN ---- */
.welcome-message {
    text-align: center;
    padding: 48px 24px;
    max-width: 600px;
    margin: 0 auto;
    width: 100%;
}

.welcome-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.welcome-subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
}

.welcome-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
    gap: 24px;
    margin-top: 32px;
}

.feature-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 20px;
    text-align: left;
}
.feature-icon {
    width: 36px;
    height: 36px;
    background: var(--accent);
    color: #fff;
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 12px;
}

/* ---- TABLES ---- */
table {
    border-collapse: collapse;
    width: 100%;
    margin: 12px 0;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 6px;
    overflow: hidden;
    display: table;
    table-layout: auto;
}

th, td {
    padding: 8px 12px;
    border: 1px solid var(--border);
    text-align: left;
    white-space: normal;
    word-wrap: break-word;
    min-width: 120px;
}

th {
    background: var(--bg-tertiary);
    font-weight: 600;
}

tr:nth-child(even) {
    background: rgba(255,255,255,0.03);
}

/* Table wrapper for mobile scrolling */
.message-content {
    overflow-x: auto;
}

.message-content table {
    min-width: 100%;
}

/* ---- MODAL POPUP ---- */
.modal {
    position: fixed;
    z-index: 10000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.7);
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-content {
    background-color: var(--bg-secondary);
    margin: auto;
    padding: 0;
    border: 1px solid var(--border);
    border-radius: 8px;
    width: 90%;
    max-width: 600px;
    max-height: 80vh;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0,0,0,0.5);
}

.modal-header {
    padding: 16px 20px;
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--bg-tertiary);
}

.modal-header h3 {
    margin: 0;
    color: var(--text-primary);
}

.close {
    color: var(--text-secondary);
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    line-height: 1;
}

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

.modal-body {
    padding: 20px;
    max-height: 60vh;
    overflow-y: auto;
    color: var(--text-primary);
    line-height: 1.6;
}

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

.settings-section h4 {
    margin-bottom: 12px;
    color: var(--text-primary);
    font-size: 1.1rem;
    border-bottom: 1px solid var(--border);
    padding-bottom: 8px;
}

.setting-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
    padding: 8px 0;
}

.setting-item label {
    color: var(--text-primary);
    font-weight: 500;
}

.setting-item select,
.setting-item input[type="checkbox"] {
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    color: var(--text-primary);
    padding: 6px 12px;
    border-radius: 4px;
}

.setting-item input[type="checkbox"] {
    width: 18px;
    height: 18px;
}

.system-prompt-input {
    width: 100%;
    resize: vertical;
    min-height: 90px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    color: var(--text-primary);
    padding: 10px 12px;
    border-radius: 6px;
    outline: none;
    line-height: 1.4;
}

.system-prompt-input:focus {
    border-color: var(--accent);
}

/* Export settings buttons */
.setting-item .action-btn {
    padding: 6px 12px;
    border-radius: 4px;
    border: none;
    cursor: pointer;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 6px;
    transition: all 0.2s ease;
}

.setting-item .action-btn:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

.setting-item .action-btn:active {
    transform: translateY(0);
}

/* ---- Additional Markdown Styles ---- */
blockquote {
    border-left: 3px solid var(--accent);
    padding-left: 12px;
    margin: 8px 0;
    color: var(--text-secondary);
    font-style: italic;
}

ul, ol {
    margin: 8px 0;
    padding-left: 24px;
}

li {
    margin: 4px 0;
}

hr {
    border: none;
    border-top: 1px solid var(--border);
    margin: 16px 0;
}

img {
    max-width: 100%;
    border-radius: 6px;
    margin: 8px 0;
}

a {
    color: var(--accent);
    text-decoration: none;
}
a:hover {
    text-decoration: underline;
}

h1, h2, h3, h4, h5, h6 {
    margin: 16px 0 8px 0;
    line-height: 1.3;
}
h1 { font-size: 1.8rem; }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.3rem; }
h4 { font-size: 1.1rem; }
h5 { font-size: 1rem; }
h6 { font-size: 0.9rem; }

/* ========== COMPACT MODE ========== */
body.compact-mode {
    --font-size-base: 14px;
    font-size: var(--font-size-base);
}

body.compact-mode .message {
    padding: 8px 12px;
    margin-bottom: 6px;
}

body.compact-mode .message-content {
    margin: 6px 0;
}

body.compact-mode .input-container {
    padding: 8px;
}

body.compact-mode .settings-section {
    padding: 12px;
    margin-bottom: 8px;
}

body.compact-mode .setting-item {
    margin-bottom: 8px;
}

/* Font size variations */
:root[data-font-size="small"] {
    --font-size-base: 14px;
}

:root[data-font-size="medium"] {
    --font-size-base: 16px;
}

:root[data-font-size="large"] {
    --font-size-base: 18px;
}

/* ========== RESPONSIVE DESIGN ========== */

/* Tablet and Mobile */
@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        left: -100%;
        top: 0;
        height: 100%;
        width: 280px;
        z-index: 1001;
        transition: left 0.3s ease;
        box-shadow: 2px 0 10px rgba(0,0,0,0.3);
    }
    .sidebar.open {
        left: 0;
    }
    .sidebar-close-btn {
        display: block;
    }
    .mobile-menu-btn {
        display: block;
    }
    .main-content {
        width: 100%;
    }
    
    /* Chat header mobile fixes */
    .chat-header {
        padding: 8px 12px;
        flex-wrap: wrap;
        gap: 8px;
        min-height: 56px;
        position: sticky;
        top: 0;
        z-index: 100;
        background: var(--bg-secondary);
    }
    
    .header-actions {
        gap: 6px;
    }
    
    .model-selector {
        max-width: 80px;
        min-width: 80px;
        font-size: 0.8rem;
        padding: 6px 8px;
    }
    
    .theme-toggle-btn,
    .settings-btn {
        padding: 6px 8px;
        font-size: 0.9rem;
    }
    
    .chat-messages {
        padding: 16px;
    }
    
    .chat-input-container {
        padding: 16px;
    }
    
    .message {
        margin-bottom: 16px;
        gap: 12px;
    }
    
    .message-content {
        padding: 10px 12px;
        font-size: 0.95rem;
    }
    
    .message-actions {
        opacity: 1; /* Always show on mobile for better UX */
        margin-top: 6px;
    }
    
    .action-btn {
        padding: 6px 10px;
        font-size: 0.8rem;
    }
    
    .welcome-features {
        grid-template-columns: 1fr;
        gap: 16px;
    }
    
    .feature-card {
        padding: 16px;
    }
    
    /* Mobile table improvements */
    table {
        font-size: 0.9rem;
        min-width: 100%;
    }
    
    th, td {
        padding: 6px 8px;
        min-width: 80px;
        max-width: 200px;
        word-wrap: break-word;
    }
}

/* Small Mobile */
@media (max-width: 480px) {
    .sidebar {
        width: 100%;
    }
    
    .chat-header {
        padding: 6px 10px;
        min-height: 50px;
    }
    
    .chat-title {
        font-size: 0.9rem;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
        max-width: 120px;
    }
    
    .header-actions {
        gap: 4px;
    }
    
    /* Hide less important elements on very small screens */
    #userDisplay {
        display: none;
    }
    
    .online-status {
        font-size: 10px;
        padding: 2px 4px;
    }
    
    .model-selector {
        max-width: 70px;
        min-width: 60px;
        font-size: 0.7rem;
        padding: 4px 6px;
    }
    
    /* Compact buttons */
    .theme-toggle-btn,
    .settings-btn {
        padding: 4px 6px;
        min-width: 32px;
        display: flex;
        align-items: center;
        justify-content: center;
    }
    
    .theme-toggle-btn i,
    .settings-btn i {
        margin: 0;
    }
    
    .message-content {
        padding: 8px 10px;
        font-size: 0.9rem;
    }
    
    .message-avatar {
        width: 24px;
        height: 24px;
        font-size: 0.8rem;
    }
    
    .message {
        gap: 8px;
    }
    
    .edit-textarea {
        min-height: 60px;
        font-size: 0.9rem;
    }
    
    .edit-actions {
        flex-direction: column;
        gap: 6px;
    }
    
    .edit-actions .action-btn {
        width: 100%;
        justify-content: center;
    }
    
    .chat-messages {
        padding: 12px;
    }
    
    .chat-input-container {
        padding: 12px;
    }
    
    .action-btn {
        padding: 4px 8px;
        font-size: 0.75rem;
    }
}

/* Very Small Mobile (Emergency layout) */
@media (max-width: 360px) {
    .chat-header {
        flex-direction: column;
        align-items: stretch;
        gap: 6px;
        min-height: auto;
        padding: 8px 10px;
    }
    
    .header-actions {
        order: 2;
        margin-top: 6px;
        width: 100%;
        justify-content: space-between;
    }
    
    .chat-title {
        order: 1;
        text-align: center;
        max-width: 100%;
        margin-bottom: 4px;
    }
    
    .mobile-menu-btn {
        position: absolute;
        left: 10px;
        top: 50%;
        transform: translateY(-50%);
    }
    
    .model-selector {
        max-width: 60px;
        min-width: 50px;
        font-size: 0.65rem;
    }
    
    .theme-toggle-btn,
    .settings-btn {
        padding: 3px 5px;
        font-size: 0.8rem;
    }
}