/* eStudy Main Styling Document */

/* Define CSS Variables for Themes */
:root {
    /* Fonts */
    --font-serif: 'Noto Serif SC', Georgia, serif;
    --font-sans: 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    
    /* Academic Light Theme (Paper-like, Scholar aesthetics) */
    --bg-app: #f5f3eb;
    --bg-panel: #ffffff;
    --bg-active: #ebe7db;
    --bg-bubble-self: #f0ede4;
    --bg-bubble-ai: #fcfbfa;
    --border-color: #dfdbcf;
    --text-main: #2d2c28;
    --text-muted: #6e6b64;
    --accent-color: #4e645a; /* Warm Forest Scholar Green */
    --accent-hover: #3c4e46;
    --shadow-color: rgba(66, 62, 53, 0.08);
    --shadow-hover: rgba(66, 62, 53, 0.15);
    --modal-overlay: rgba(30, 29, 27, 0.4);
    --selection-color: rgba(78, 100, 90, 0.2);
}

.theme-dark {
    /* Academic Dark Theme */
    --bg-app: #131312;
    --bg-panel: #1a1a19;
    --bg-active: #282826;
    --bg-bubble-self: #232321;
    --bg-bubble-ai: #1d1d1c;
    --border-color: #2b2b29;
    --text-main: #e2e1dd;
    --text-muted: #9c9a94;
    --accent-color: #8da497; /* Soft Sage Green */
    --accent-hover: #abc0b3;
    --shadow-color: rgba(0, 0, 0, 0.3);
    --shadow-hover: rgba(0, 0, 0, 0.5);
    --modal-overlay: rgba(0, 0, 0, 0.7);
    --selection-color: rgba(141, 164, 151, 0.3);
}

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

body {
    font-family: var(--font-sans);
    background-color: var(--bg-app);
    color: var(--text-main);
    overflow: hidden;
    line-height: 1.5;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Scrollbar Customization */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}
::-webkit-scrollbar-track {
    background: transparent;
}
::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* App Layout Grid */
.app-layout {
    display: flex;
    flex-direction: column;
    height: 100vh;
    width: 100vw;
}

/* App Header Styling */
.app-header {
    height: 56px;
    background-color: var(--bg-panel);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 16px;
    z-index: 10;
    box-shadow: 0 1px 3px var(--shadow-color);
}

.header-left, .header-right {
    display: flex;
    align-items: center;
    gap: 12px;
}

.header-center {
    flex: 1;
    text-align: center;
    max-width: 50%;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.logo {
    display: flex;
    align-items: center;
    gap: 6px;
    user-select: none;
}

.logo-serif {
    font-family: var(--font-serif);
    font-size: 22px;
    font-weight: 700;
    letter-spacing: -0.5px;
    color: var(--accent-color);
}

.logo-badge {
    font-size: 9px;
    background-color: var(--accent-color);
    color: var(--bg-panel);
    padding: 2px 4px;
    border-radius: 3px;
    font-weight: 600;
    letter-spacing: 1px;
}

.doc-title {
    font-family: var(--font-serif);
    font-weight: 600;
    color: var(--text-main);
    font-size: 15px;
}

/* Buttons Styling */
.icon-btn {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    border: none;
    background: transparent;
    color: var(--text-main);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 16px;
    transition: background-color 0.2s, color 0.2s;
}

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

.admin-link-btn {
    text-decoration: none;
    font-size: 13px;
    font-weight: 500;
    padding: 6px 12px;
    border-radius: 18px;
    border: 1px solid var(--border-color);
    color: var(--text-main);
    background-color: var(--bg-panel);
    display: flex;
    align-items: center;
    gap: 6px;
    transition: all 0.2s;
}

.admin-link-btn:hover {
    background-color: var(--accent-color);
    color: var(--bg-panel);
    border-color: var(--accent-color);
}

.admin-logout-btn {
    text-decoration: none;
    font-size: 13px;
    font-weight: 500;
    padding: 6px 12px;
    border-radius: 18px;
    border: 1px solid var(--border-color);
    color: var(--text-muted);
    background-color: var(--bg-panel);
    display: flex;
    align-items: center;
    gap: 6px;
    transition: all 0.2s;
}

.admin-logout-btn:hover {
    background-color: #c94c4c;
    color: #ffffff;
    border-color: #c94c4c;
}

/* Main Workspace */
.app-main {
    flex: 1;
    display: flex;
    overflow: hidden;
    position: relative;
}

/* Sidebars Base Structure */
.sidebar {
    position: relative;
    width: 340px;
    background-color: var(--bg-panel);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    z-index: 5;
    transition: margin-left 0.3s cubic-bezier(0.4, 0, 0.2, 1), margin-right 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    flex-shrink: 0;
}

.left-sidebar {
    margin-left: 0;
}

.left-sidebar.collapsed {
    margin-left: -340px;
}

.right-sidebar {
    width: 450px;
    border-right: none;
    border-left: 1px solid var(--border-color);
    margin-right: 0;
}

.right-sidebar.collapsed {
    margin-right: -450px;
}

.sidebar-header {
    height: 48px;
    padding: 0 16px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    font-family: var(--font-serif);
}

.sidebar-header h3 {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-main);
    display: flex;
    align-items: center;
    gap: 8px;
}

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

/* Category Tree in Left Sidebar */
.category-tree {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.parent-cat {
    border-bottom: 1px dashed var(--border-color);
    padding-bottom: 6px;
}

.parent-cat-title {
    font-size: 16.5px;
    font-weight: 600;
    padding: 6px 8px;
    cursor: pointer;
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    transition: background-color 0.2s;
    color: var(--text-main);
    user-select: none;
}

.parent-cat-title:hover {
    background-color: var(--bg-active);
}

.parent-cat-title .cat-chevron {
    font-size: 10px;
    transition: transform 0.2s;
    color: var(--text-muted);
}

.parent-cat.collapsed .parent-cat-title .cat-chevron {
    transform: rotate(-90deg);
}

.sub-cats-list {
    margin-left: 12px;
    margin-top: 4px;
    display: flex;
    flex-direction: column;
    gap: 4px;
    transition: max-height 0.3s ease, opacity 0.3s ease;
    overflow: hidden;
}

.parent-cat.collapsed .sub-cats-list {
    max-height: 0 !important;
    opacity: 0;
    margin-top: 0;
}

.sub-cat-item {
    font-size: 15px;
    font-weight: 500;
    padding: 4px 8px;
    color: var(--text-muted);
    border-left: 2px solid transparent;
}

.sub-cat-header {
    display: flex;
    align-items: center;
    gap: 6px;
    margin-bottom: 4px;
    font-weight: 600;
    color: var(--text-main);
}

.files-list {
    display: flex;
    flex-direction: column;
    gap: 2px;
    margin-left: 12px;
}

.file-link {
    display: flex;
    align-items: flex-start;
    gap: 6px;
    padding: 6px 8px;
    color: var(--text-muted);
    text-decoration: none;
    border-radius: 3px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.2s;
    white-space: normal;
    word-break: break-all;
    line-height: 1.4;
}

.file-link:hover {
    background-color: var(--bg-active);
    color: var(--accent-color);
}

.file-link.active {
    background-color: var(--bg-active);
    color: var(--accent-color);
    font-weight: 500;
    border-left: 2px solid var(--accent-color);
}

.sidebar-loading {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    height: 100px;
    color: var(--text-muted);
    font-size: 12px;
}

/* Center Reader Workspace */
.reader-workspace {
    flex: 1;
    display: flex;
    flex-direction: column;
    position: relative;
    background-color: var(--bg-app);
    overflow: hidden;
}

/* Reader Toolbar */
.reader-toolbar {
    height: 48px;
    background-color: var(--bg-panel);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 16px;
    z-index: 4;
    transition: opacity 0.3s;
}

.reader-toolbar.hidden {
    display: none !important;
}

.toolbar-left, .toolbar-center, .toolbar-right {
    display: flex;
    align-items: center;
    gap: 12px;
}

.tool-btn {
    width: 32px;
    height: 32px;
    background: transparent;
    border: 1px solid transparent;
    border-radius: 4px;
    cursor: pointer;
    color: var(--text-main);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
}

.tool-btn:hover {
    background-color: var(--bg-active);
    border-color: var(--border-color);
}

.page-indicator {
    font-size: 13px;
    color: var(--text-muted);
}

.page-indicator input {
    width: 45px;
    padding: 2px 4px;
    border: 1px solid var(--border-color);
    border-radius: 3px;
    background-color: var(--bg-app);
    color: var(--text-main);
    text-align: center;
    font-size: 13px;
    font-family: inherit;
}

.zoom-level {
    font-size: 13px;
    min-width: 40px;
    text-align: center;
    font-weight: 500;
}

/* PDF View Container */
.pdf-container-wrapper {
    flex: 1;
    overflow: auto;
    position: relative;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    padding: 20px;
}

/* Welcome Card Screen */
.reader-welcome {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
    height: 100%;
}

.welcome-card {
    background-color: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 48px;
    max-width: 760px;
    box-shadow: 0 4px 20px var(--shadow-color);
    text-align: center;
}

.welcome-icon {
    font-size: 40px;
    color: var(--accent-color);
    margin-bottom: 16px;
    opacity: 0.8;
}

.welcome-card h2 {
    font-family: var(--font-serif);
    font-size: clamp(22px, 2.4vw, 38px);
    margin-bottom: 16px;
    color: var(--accent-color);
    font-weight: 800;
    letter-spacing: 2px;
    line-height: 1.3;
    white-space: nowrap;
}

.welcome-card p {
    font-size: 13px;
    color: var(--text-muted);
    margin-bottom: 24px;
    line-height: 1.6;
}

.welcome-tips {
    text-align: left;
    background-color: var(--bg-app);
    border-radius: 6px;
    padding: 16px;
    border: 1px solid var(--border-color);
}

.welcome-tips p {
    margin-bottom: 8px;
    color: var(--text-main);
}

.welcome-tips ul {
    list-style-type: none;
}

.welcome-tips li {
    font-size: 12.5px;
    color: var(--text-muted);
    margin-bottom: 6px;
    position: relative;
    padding-left: 14px;
}

.welcome-tips li::before {
    content: "•";
    position: absolute;
    left: 4px;
    color: var(--accent-color);
}

/* PDF Pages Rendering Style */
.pdf-viewer {
    display: flex;
    flex-direction: column;
    gap: 20px;
    align-items: center;
}

.pdf-viewer.hidden {
    display: none;
}

.pdf-page-container {
    position: relative;
    box-shadow: 0 4px 15px var(--shadow-color);
    background-color: #ffffff;
    border: 1px solid var(--border-color);
    transition: box-shadow 0.3s;
}

.pdf-page-container:hover {
    box-shadow: 0 8px 24px var(--shadow-hover);
}

.pdf-page-container canvas {
    display: block;
}

/* PDF Text Layer (For selection) */
.textLayer {
    position: absolute;
    left: 0;
    top: 0;
    right: 0;
    bottom: 0;
    overflow: hidden;
    opacity: 0.2; /* Visible selection but transparent font, typical pdfjs setup */
    line-height: 1.0;
    mix-blend-mode: multiply;
}

.textLayer span, .textLayer br {
    color: transparent;
    position: absolute;
    white-space: pre;
    cursor: text;
    transform-origin: 0% 0%;
}

.textLayer ::selection {
    background: var(--selection-color);
}

/* Floating Context Menu (Pop-up on select) */
.float-menu {
    position: fixed;
    z-index: 100;
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    box-shadow: 0 4px 20px var(--shadow-color);
    border-radius: 8px;
    display: flex;
    padding: 4px;
    gap: 2px;
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    transition: transform 0.15s cubic-bezier(0.2, 0.9, 0.3, 1), opacity 0.15s ease;
}

.float-menu.hidden {
    display: none !important;
    opacity: 0;
    pointer-events: none;
}

.float-item {
    background: transparent;
    border: none;
    border-radius: 6px;
    padding: 6px 12px;
    font-size: 12px;
    font-weight: 500;
    color: var(--text-main);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 6px;
    transition: background-color 0.2s, color 0.2s;
    font-family: inherit;
}

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

.float-item i {
    font-size: 13px;
    color: var(--accent-color);
}

/* Right Sidebar: AI Assistant / Study Panel */
.assistant-tabs {
    display: flex;
    height: 48px;
    border-bottom: 1px solid var(--border-color);
    background-color: var(--bg-panel);
}

.tab-btn {
    flex: 1;
    border: none;
    background: transparent;
    color: var(--text-muted);
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    border-bottom: 2px solid transparent;
    transition: all 0.2s;
    font-family: var(--font-serif);
}

.tab-btn:hover {
    color: var(--text-main);
}

.tab-btn.active {
    color: var(--accent-color);
    border-bottom-color: var(--accent-color);
    background-color: rgba(78, 100, 90, 0.03);
}

.close-sidebar-btn {
    border: none;
    background: transparent;
    color: var(--text-muted);
    font-size: 13px;
    font-weight: 600;
    padding: 0 16px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 6px;
    transition: all 0.2s;
    font-family: var(--font-serif);
    border-left: 1px solid var(--border-color);
}

.close-sidebar-btn:hover {
    color: #c94c4c;
    background-color: rgba(201, 76, 76, 0.05);
}

.close-sidebar-btn i {
    font-size: 12px;
}

.assistant-content {
    flex: 1;
    overflow: hidden;
    position: relative;
    display: flex;
    flex-direction: column;
}

.tab-pane {
    display: none;
    flex: 1;
    flex-direction: column;
    overflow: hidden;
}

.tab-pane.active {
    display: flex;
}

/* Chat Tab Q&A Area */
.chat-messages {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    background-color: rgba(245, 243, 235, 0.3); /* Warm tint background */
}

.theme-dark .chat-messages {
    background-color: rgba(20, 20, 19, 0.3);
}

/* Message styling - Academical Journal Notebook aesthetic */
.chat-msg {
    display: flex;
    gap: 12px;
    align-items: flex-start;
    animation: slideIn 0.3s cubic-bezier(0.2, 0.8, 0.2, 1);
}

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

.msg-avatar {
    width: 28px;
    height: 28px;
    border-radius: 4px;
    background-color: var(--bg-active);
    color: var(--accent-color);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 13px;
    flex-shrink: 0;
    border: 1px solid var(--border-color);
}

.chat-msg.self .msg-avatar {
    background-color: var(--accent-color);
    color: var(--bg-panel);
    order: 2;
}

.msg-bubble {
    flex: 1;
    background-color: var(--bg-bubble-ai);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 12px;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-main);
    box-shadow: 0 1px 3px var(--shadow-color);
    word-break: break-word;
    overflow-wrap: break-word;
}

.msg-bubble img {
    max-width: 100%;
    height: auto;
    border-radius: 4px;
    margin-top: 8px;
    margin-bottom: 8px;
    display: block;
    box-shadow: 0 2px 8px var(--shadow-color);
}

.msg-bubble a.chat-link {
    color: var(--accent-color);
    text-decoration: underline;
    font-weight: 500;
}

.msg-bubble a.chat-link:hover {
    color: var(--accent-hover);
}

.chat-msg.self .msg-bubble {
    background-color: var(--bg-bubble-self);
    order: 1;
}

.msg-bubble h1, .msg-bubble h2, .msg-bubble h3 {
    font-family: var(--font-serif);
    font-size: 16px;
    font-weight: 700;
    margin-top: 12px;
    margin-bottom: 8px;
    color: var(--accent-color);
    border-bottom: 1px dashed var(--border-color);
    padding-bottom: 4px;
}

.msg-bubble h4, .msg-bubble h5, .msg-bubble h6 {
    font-size: 14px;
    font-weight: 700;
    margin-top: 10px;
    margin-bottom: 6px;
    color: var(--text-main);
}

.msg-bubble p {
    margin-bottom: 8px;
}

.msg-bubble p:last-child {
    margin-bottom: 0;
}

.msg-bubble ul, .msg-bubble ol {
    margin-left: 16px;
    margin-bottom: 8px;
}

.msg-bubble blockquote {
    border-left: 3px solid var(--accent-color);
    padding-left: 10px;
    color: var(--text-muted);
    font-style: italic;
    background-color: var(--bg-active);
    margin: 8px 0;
    padding-top: 4px;
    padding-bottom: 4px;
    border-radius: 0 4px 4px 0;
}

/* Alerts inside messages */
.msg-bubble blockquote:has(strong:contains("[!")) {
    border-radius: 4px;
}

/* Simple Loading Animation inside notebook */
.typing-loader {
    display: flex;
    gap: 4px;
    padding: 8px 4px;
}

.typing-loader span {
    width: 6px;
    height: 6px;
    background-color: var(--accent-color);
    border-radius: 50%;
    display: inline-block;
    animation: bounce 1.4s infinite ease-in-out both;
}

.typing-loader span:nth-child(1) { animation-delay: -0.32s; }
.typing-loader span:nth-child(2) { animation-delay: -0.16s; }

@keyframes bounce {
    0%, 80%, 100% { transform: scale(0); }
    40% { transform: scale(1.0); }
}

/* Chat Input Bar */
.chat-input-wrapper {
    padding: 12px;
    background-color: var(--bg-panel);
    border-top: 1px solid var(--border-color);
}

.chat-context-preview {
    background-color: var(--bg-active);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 6px 10px;
    margin-bottom: 8px;
    font-size: 11px;
}

.chat-context-preview .context-hdr {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--accent-color);
    font-weight: 600;
    margin-bottom: 4px;
}

.chat-context-preview .context-text {
    color: var(--text-muted);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    font-style: italic;
}

.small-btn {
    background: transparent;
    border: none;
    cursor: pointer;
    color: var(--text-muted);
    font-size: 12px;
}
.small-btn:hover {
    color: var(--text-main);
}

.input-row {
    display: flex;
    gap: 8px;
    align-items: flex-end;
}

.input-row textarea {
    flex: 1;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 8px 10px;
    background-color: var(--bg-app);
    color: var(--text-main);
    font-family: inherit;
    font-size: 14.5px;
    resize: none;
    outline: none;
    transition: border-color 0.2s;
}

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

.send-btn {
    width: 36px;
    height: 36px;
    border-radius: 6px;
    border: none;
    background-color: var(--accent-color);
    color: var(--bg-panel);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.2s;
}

.send-btn:hover {
    background-color: var(--accent-hover);
}

.input-actions {
    display: flex;
    justify-content: space-between;
    margin-top: 8px;
}

.icon-link-btn {
    background: transparent;
    border: none;
    font-size: 11px;
    color: var(--text-muted);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 4px;
    transition: color 0.2s;
}

.icon-link-btn:hover {
    color: var(--accent-color);
}

/* Overview Tab Styling */
.doc-overview-pane {
    padding: 16px;
    overflow-y: auto;
    height: 100%;
}

.doc-overview-pane h4 {
    font-family: var(--font-serif);
    font-size: 15px;
    color: var(--text-main);
    margin-bottom: 16px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 8px;
}

.overview-section {
    margin-bottom: 20px;
}

.overview-section h5 {
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--accent-color);
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    gap: 6px;
}

.progress-bar-container {
    height: 6px;
    background-color: var(--bg-active);
    border-radius: 3px;
    overflow: hidden;
    margin-bottom: 6px;
}

.progress-bar {
    height: 100%;
    background-color: var(--accent-color);
    border-radius: 3px;
    transition: width 0.3s ease;
}

.progress-text {
    font-size: 11px;
    color: var(--text-muted);
}

.category-tag {
    display: inline-block;
    padding: 3px 8px;
    border-radius: 12px;
    background-color: var(--bg-active);
    border: 1px solid var(--border-color);
    font-size: 11px;
    color: var(--accent-color);
    font-weight: 500;
}

.study-tips-list {
    margin-left: 14px;
    font-size: 12px;
    color: var(--text-muted);
    line-height: 1.7;
}

.study-tips-list li {
    margin-bottom: 8px;
}

/* Modal Styling */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background-color: var(--modal-overlay);
    z-index: 100;
    display: flex;
    justify-content: center;
    align-items: center;
    opacity: 1;
    transition: opacity 0.3s;
}

.modal-overlay.hidden {
    display: none !important;
    opacity: 0;
}

.modal-content {
    background-color: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    width: 90%;
    max-width: 460px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.25);
    overflow: hidden;
    animation: modalSlide 0.3s cubic-bezier(0.2, 0.8, 0.2, 1);
}

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

.modal-header {
    padding: 14px 16px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h4 {
    font-family: var(--font-serif);
    font-size: 15px;
    color: var(--text-main);
    display: flex;
    align-items: center;
    gap: 8px;
}

.modal-close {
    background: transparent;
    border: none;
    font-size: 20px;
    cursor: pointer;
    color: var(--text-muted);
}
.modal-close:hover {
    color: var(--text-main);
}

.modal-body {
    padding: 16px;
}

.modal-tip {
    font-size: 11px;
    color: var(--text-muted);
    background-color: var(--bg-app);
    padding: 8px;
    border-radius: 4px;
    margin-bottom: 16px;
    border-left: 2px solid var(--accent-color);
}

.form-group {
    margin-bottom: 14px;
}

.form-group label {
    display: block;
    font-size: 12px;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--text-main);
}

.form-group input {
    width: 100%;
    padding: 8px 10px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background-color: var(--bg-app);
    color: var(--text-main);
    font-family: inherit;
    font-size: 13px;
    outline: none;
}
.form-group input:focus {
    border-color: var(--accent-color);
}

.modal-footer {
    padding: 12px 16px;
    background-color: var(--bg-app);
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: flex-end;
    gap: 10px;
}

.primary-btn, .secondary-btn {
    padding: 8px 16px;
    border-radius: 4px;
    font-size: 12.5px;
    font-weight: 500;
    cursor: pointer;
    border: none;
    font-family: inherit;
    transition: all 0.2s;
}

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

.secondary-btn {
    background-color: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-main);
}
.secondary-btn:hover {
    background-color: var(--bg-active);
}

/* =========================================
   ADMIN PANEL STYLING (Exclusive elements)
   ========================================= */
.admin-body {
    overflow-y: auto !important;
}

.admin-container {
    max-width: 1100px;
    margin: 40px auto;
    padding: 0 20px;
}

.admin-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border-color);
}

.admin-header .back-link {
    text-decoration: none;
    color: var(--accent-color);
    font-size: 13px;
    font-weight: 500;
    display: inline-block;
    margin-bottom: 6px;
}

.admin-header .back-link:hover {
    text-decoration: underline;
}

.admin-header h2 {
    font-family: var(--font-serif);
    font-size: 22px;
}

.badge {
    padding: 4px 10px;
    border-radius: 12px;
    background-color: var(--bg-active);
    border: 1px solid var(--border-color);
    font-size: 11.5px;
    color: var(--accent-color);
    font-weight: 600;
}

.admin-grid {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 20px;
    margin-bottom: 24px;
}

.admin-card {
    background-color: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    box-shadow: 0 2px 10px var(--shadow-color);
    overflow: hidden;
}

.admin-card.full-width {
    grid-column: 1 / -1;
}

.card-header {
    padding: 14px 16px;
    border-bottom: 1px solid var(--border-color);
    background-color: rgba(78, 100, 90, 0.02);
}

.card-header h3 {
    font-family: var(--font-serif);
    font-size: 14px;
    color: var(--text-main);
    display: flex;
    align-items: center;
    gap: 8px;
}

.card-body {
    padding: 16px;
}

.admin-form-group {
    margin-bottom: 16px;
}

.admin-form-group label {
    display: block;
    font-size: 12px;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--text-muted);
}

.input-inline {
    display: flex;
    gap: 8px;
}

.input-inline input, .form-row input {
    flex: 1;
    padding: 8px 10px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background-color: var(--bg-app);
    color: var(--text-main);
    font-family: inherit;
    font-size: 13px;
    outline: none;
}

.form-row {
    display: flex;
    gap: 8px;
}

.form-row select, .form-group select {
    flex: 1;
    padding: 8px 10px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background-color: var(--bg-app);
    color: var(--text-main);
    font-family: inherit;
    font-size: 13px;
    outline: none;
}

.btn {
    padding: 8px 14px;
    border-radius: 4px;
    border: none;
    background-color: var(--accent-color);
    color: var(--bg-panel);
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    font-family: inherit;
    transition: background-color 0.2s;
    white-space: nowrap;
}

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

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

/* Drag & Drop File Container */
.file-drop-area {
    border: 2px dashed var(--border-color);
    border-radius: 6px;
    padding: 24px;
    text-align: center;
    background-color: var(--bg-app);
    cursor: pointer;
    transition: all 0.2s;
}

.file-drop-area:hover, .file-drop-area.highlight {
    border-color: var(--accent-color);
    background-color: var(--bg-active);
}

.file-drop-area i {
    font-size: 36px;
    color: var(--text-muted);
    margin-bottom: 10px;
    display: block;
}

.file-drop-area p {
    font-size: 12px;
    color: var(--text-main);
    margin-bottom: 6px;
}

.file-name-preview {
    font-size: 11px;
    color: var(--text-muted);
    font-style: italic;
    word-break: break-all;
}

.file-drop-area.has-file i {
    color: var(--accent-color);
}

.btn-block {
    width: 100%;
    display: block;
    margin-top: 12px;
}

/* Category structure inside list */
.categories-list-wrapper label {
    display: block;
    font-size: 12px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-muted);
}

.admin-category-tree-list {
    max-height: 250px;
    overflow-y: auto;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 8px;
    background-color: var(--bg-app);
}

.admin-parent-cat-item {
    margin-bottom: 10px;
}

.admin-cat-title-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 4px 6px;
    background-color: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: 4px;
}

.cat-name {
    font-size: 12px;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 6px;
}

.parent-name {
    font-weight: 600;
    color: var(--text-main);
}

.delete-cat-btn {
    background: transparent;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    font-size: 11px;
    padding: 2px 6px;
    border-radius: 3px;
}
.delete-cat-btn:hover {
    color: #c94c4c;
    background-color: rgba(201, 76, 76, 0.05);
}

.admin-sub-cat-container {
    margin-left: 16px;
    margin-top: 4px;
    border-left: 1px dotted var(--border-color);
    padding-left: 8px;
    display: flex;
    flex-direction: column;
    gap: 3px;
}

.admin-sub-cat-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 3px 6px;
    background-color: rgba(255,255,255,0.4);
    border-radius: 3px;
}

.admin-empty-sub-tip {
    font-size: 10.5px;
    color: var(--text-muted);
    font-style: italic;
    padding-left: 6px;
}

/* File list table */
.table-responsive {
    overflow-x: auto;
}

.admin-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 12.5px;
    text-align: left;
}

.admin-table th, .admin-table td {
    padding: 10px 12px;
    border-bottom: 1px solid var(--border-color);
}

.admin-table th {
    font-family: var(--font-serif);
    font-weight: 600;
    color: var(--text-main);
    background-color: var(--bg-app);
}

.admin-table tbody tr:hover {
    background-color: rgba(78, 100, 90, 0.02);
}

.cat-badge {
    display: inline-block;
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 10.5px;
    font-weight: 500;
}

.parent-badge {
    background-color: var(--bg-active);
    color: var(--text-main);
    border: 1px solid var(--border-color);
}

.sub-badge {
    background-color: rgba(78, 100, 90, 0.08);
    color: var(--accent-color);
    border: 1px solid rgba(78, 100, 90, 0.15);
}

.delete-file-btn {
    background-color: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-muted);
    padding: 4px 8px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 11px;
    font-family: inherit;
    transition: all 0.2s;
}

.delete-file-btn:hover {
    background-color: #c94c4c;
    color: #ffffff;
    border-color: #c94c4c;
}

.text-center { text-align: center !important; }
.text-muted { color: var(--text-muted) !important; }
.text-muted small { font-size: 10px; }

.direct-badge {
    background-color: rgba(110, 107, 100, 0.08) !important;
    color: var(--text-muted) !important;
    border: 1px solid var(--border-color) !important;
    font-style: italic;
}

.sidebar-footer {
    height: 44px;
    border-top: 2px solid var(--accent-color);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12.5px;
    font-weight: 600;
    color: var(--accent-color);
    background-color: rgba(78, 100, 90, 0.06);
    user-select: none;
    flex-shrink: 0;
    letter-spacing: 0.5px;
}

.admin-footer {
    text-align: center;
    margin-top: 40px;
    padding: 16px 0;
    border-top: 2px solid var(--accent-color);
    font-size: 12.5px;
    font-weight: 600;
    color: var(--accent-color);
    background-color: rgba(78, 100, 90, 0.06);
    border-radius: 4px;
}

.float-sidebar-toggle-btn {
    position: fixed;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
    background-color: var(--accent-color);
    color: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-right: none;
    border-radius: 8px 0 0 8px;
    padding: 16px 8px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    z-index: 99;
    box-shadow: -2px 4px 12px var(--shadow-hover);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.float-sidebar-toggle-btn:hover {
    background-color: var(--accent-hover);
    padding-right: 12px;
}

.float-sidebar-toggle-btn.hidden {
    transform: translate(100%, -50%);
    pointer-events: none;
    opacity: 0;
}

.float-sidebar-toggle-btn span {
    writing-mode: vertical-rl;
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 2px;
}

/* Sidebar Protruding Collapse Button style */
.sidebar-collapse-left-btn {
    position: absolute;
    left: 0;
    top: 50%;
    transform: translate(-100%, -50%);
    background-color: var(--accent-color);
    color: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-right: none;
    border-radius: 8px 0 0 8px;
    padding: 16px 8px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    z-index: 99;
    box-shadow: -2px 4px 12px var(--shadow-hover);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.sidebar-collapse-left-btn:hover {
    background-color: var(--accent-hover);
    padding-left: 12px;
}

.sidebar-collapse-left-btn span {
    writing-mode: vertical-rl;
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 2px;
}

/* Hide collapse button when sidebar is collapsed */
.right-sidebar.collapsed .sidebar-collapse-left-btn {
    opacity: 0;
    pointer-events: none;
}

/* Chat Markdown Table Styling */
.table-container {
    width: 100%;
    overflow-x: auto;
    margin: 12px 0;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background-color: var(--bg-panel);
    box-shadow: 0 1px 3px var(--shadow-color);
}

.chat-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 13.5px;
    text-align: left;
}

.chat-table th, .chat-table td {
    padding: 8px 12px;
    border-bottom: 1px solid var(--border-color);
    border-right: 1px solid var(--border-color);
    white-space: normal; /* Keep standard wrapping in cells */
}

.chat-table th:last-child, .chat-table td:last-child {
    border-right: none;
}

.chat-table th {
    font-family: var(--font-serif);
    font-weight: 600;
    color: var(--text-main);
    background-color: var(--bg-active);
}

.chat-table tbody tr:last-child td {
    border-bottom: none;
}

.chat-table tbody tr:hover {
    background-color: rgba(78, 100, 90, 0.03);
}


/* ============================================
   Enhanced Markdown Rendering Styles
   For code blocks, images, tables, and alerts
   ============================================ */

/* Code Block Wrapper */
.code-block-wrapper {
    position: relative;
    margin: 12px 0;
    border-radius: 6px;
    overflow: hidden;
    background-color: #1e1e1e;
    border: 1px solid var(--border-color);
}

.code-lang {
    position: absolute;
    top: 0;
    right: 0;
    padding: 2px 8px;
    font-size: 10px;
    color: #888;
    background-color: #2d2d2d;
    border-bottom-left-radius: 4px;
    text-transform: uppercase;
    font-family: var(--font-sans);
    letter-spacing: 0.5px;
}

.code-block {
    margin: 0;
    padding: 16px;
    padding-top: 24px;
    overflow-x: auto;
    font-size: 13px;
    line-height: 1.5;
}

.code-block code {
    font-family: 'Fira Code', 'JetBrains Mono', Consolas, Monaco, 'Courier New', monospace;
    color: #d4d4d4;
    background: transparent;
    white-space: pre;
}

/* Inline Code */
.inline-code {
    font-family: 'Fira Code', 'JetBrains Mono', Consolas, Monaco, 'Courier New', monospace;
    font-size: 0.9em;
    padding: 2px 6px;
    background-color: var(--bg-active);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    color: var(--accent-color);
}

/* Dark theme inline code */
.theme-dark .inline-code {
    background-color: #2a2a2a;
    border-color: #3a3a3a;
}

/* Chat Images - Enhanced */
.msg-bubble img.chat-image {
    max-width: 100%;
    height: auto;
    border-radius: 6px;
    margin: 8px 0;
    display: block;
    box-shadow: 0 2px 12px var(--shadow-color);
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.msg-bubble img.chat-image:hover {
    transform: scale(1.01);
    box-shadow: 0 4px 20px var(--shadow-hover);
}

/* Image Error Placeholder */
.img-error {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 12px;
    background-color: rgba(201, 76, 76, 0.1);
    border: 1px dashed #c94c4c;
    border-radius: 4px;
    color: #c94c4c;
    font-size: 12px;
    margin: 8px 0;
}

/* Table Styling */
.table-container {
    overflow-x: auto;
    margin: 12px 0;
}

.chat-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 13px;
    background-color: var(--bg-panel);
    border-radius: 6px;
    overflow: hidden;
    border: 1px solid var(--border-color);
}

.chat-table th {
    background-color: var(--bg-active);
    color: var(--accent-color);
    font-weight: 600;
    text-align: left;
    padding: 10px 12px;
    border-bottom: 2px solid var(--border-color);
}

.chat-table td {
    padding: 8px 12px;
    border-bottom: 1px solid var(--border-color);
}

.chat-table tbody tr:last-child td {
    border-bottom: none;
}

.chat-table tbody tr:hover {
    background-color: var(--bg-active);
}

/* Alert Blockquotes */
.msg-bubble blockquote.alert {
    border-radius: 6px;
    padding: 12px 16px;
    margin: 12px 0;
    border-left-width: 4px;
    font-style: normal;
}

.msg-bubble blockquote.alert strong {
    display: block;
    margin-bottom: 4px;
    font-size: 14px;
}

.msg-bubble blockquote.alert-tip {
    background-color: rgba(78, 100, 90, 0.1);
    border-color: var(--accent-color);
}

.msg-bubble blockquote.alert-note {
    background-color: rgba(59, 130, 246, 0.1);
    border-color: #3b82f6;
}

.msg-bubble blockquote.alert-warning {
    background-color: rgba(245, 158, 11, 0.1);
    border-color: #f59e0b;
}

.msg-bubble blockquote.alert-important {
    background-color: rgba(239, 68, 68, 0.1);
    border-color: #ef4444;
}

.msg-bubble blockquote.alert-caution {
    background-color: rgba(168, 85, 247, 0.1);
    border-color: #a855f7;
}

/* Links in messages */
.msg-bubble a {
    color: var(--accent-color);
    text-decoration: none;
    border-bottom: 1px dashed var(--accent-color);
    transition: color 0.2s, border-color 0.2s;
}

.msg-bubble a:hover {
    color: var(--accent-hover);
    border-bottom-color: var(--accent-hover);
}

/* Lists enhancement */
.msg-bubble ul, .msg-bubble ol {
    margin-left: 20px;
    margin-bottom: 12px;
}

.msg-bubble li {
    margin-bottom: 4px;
    line-height: 1.6;
}

/* Horizontal rule */
.msg-bubble hr {
    border: none;
    border-top: 1px solid var(--border-color);
    margin: 16px 0;
}

/* Task lists */
.msg-bubble input[type="checkbox"] {
    margin-right: 6px;
    accent-color: var(--accent-color);
}

/* Definition lists */
.msg-bubble dl {
    margin: 12px 0;
}

.msg-bubble dt {
    font-weight: 600;
    color: var(--accent-color);
}

.msg-bubble dd {
    margin-left: 16px;
    color: var(--text-muted);
    margin-bottom: 8px;
}

/* Footnotes */
.msg-bubble .footnote {
    font-size: 0.85em;
    color: var(--text-muted);
    vertical-align: super;
}

/* Strikethrough */
.msg-bubble del {
    color: var(--text-muted);
    text-decoration: line-through;
}

/* Mark/Highlight */
.msg-bubble mark {
    background-color: rgba(245, 158, 11, 0.3);
    padding: 1px 4px;
    border-radius: 2px;
}

/* Abbreviations */
.msg-bubble abbr {
    text-decoration: underline dotted;
    cursor: help;
}

/* Keyboard input */
.msg-bubble kbd {
    font-family: var(--font-sans);
    font-size: 0.85em;
    padding: 2px 6px;
    background-color: var(--bg-active);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    box-shadow: 0 1px 2px var(--shadow-color);
}

/* Subscript and Superscript */
.msg-bubble sub, .msg-bubble sup {
    font-size: 0.75em;
}

/* Details/Summary */
.msg-bubble details {
    margin: 12px 0;
    padding: 8px 12px;
    background-color: var(--bg-active);
    border: 1px solid var(--border-color);
    border-radius: 6px;
}

.msg-bubble summary {
    cursor: pointer;
    font-weight: 600;
    color: var(--accent-color);
    outline: none;
}

.msg-bubble summary:hover {
    color: var(--accent-hover);
}

.msg-bubble details[open] summary {
    margin-bottom: 8px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 8px;
}