:root {
    --primary-color: #3E63DD;
    --primary-hover: #364FC7;
    --primary-light: rgba(62, 99, 221, 0.1);
    --secondary-color: #0F172A;
    --background-color: #F8FAFC;
    --card-bg-color: #FFFFFF;
    --text-color: #1E293B;
    --text-light-color: #64748B;
    --border-color: #E2E8F0;
    --danger-color: #E11D48;
    --success-color: #10B981;
    --warning-color: #F59E0B;
    --sidebar-bg: #0F172A;
    --sidebar-active: #1E293B;
    --header-height: 64px;
    --sidebar-width: 240px;
    --border-radius: 8px;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --transition-normal: all 0.3s ease;
}

/* 暗色主题变量 */
.dark-theme {
    --primary-color: #4F74FF;
    --primary-hover: #6384FF;
    --primary-light: rgba(79, 116, 255, 0.15);
    --secondary-color: #E2E8F0;
    --background-color: #121826;
    --card-bg-color: #1E293B;
    --text-color: #E2E8F0;
    --text-light-color: #94A3B8;
    --border-color: #334155;
    --danger-color: #F43F5E;
    --success-color: #10B981;
    --warning-color: #F59E0B;
    --sidebar-bg: #0F172A;
    --sidebar-active: #1E293B;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    margin: 0;
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.6;
    height: 100vh;
    overflow: hidden;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    display: flex;
    height: 100vh;
}

/* Header Styles */
header {
    position: fixed;
    top: 0;
    left: var(--sidebar-width);
    right: 0;
    height: var(--header-height);
    background-color: var(--card-bg-color);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 24px;
    z-index: 10;
    box-shadow: var(--shadow-sm);
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

.header-left {
    display: flex;
    align-items: center;
}

header h1 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--secondary-color);
    margin: 0;
    transition: color 0.3s ease;
}

header p {
    margin-left: 12px;
    color: var(--text-light-color);
    font-size: 0.875rem;
    transition: color 0.3s ease;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 16px;
}

.theme-toggle {
    background: none;
    border: none;
    color: var(--text-light-color);
    cursor: pointer;
    font-size: 1.25rem;
    padding: 4px;
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle:hover {
    background-color: var(--primary-light);
    color: var(--primary-color);
}

/* Sidebar Styles */
.sidebar {
    width: var(--sidebar-width);
    background-color: var(--sidebar-bg);
    color: white;
    height: 100vh;
    position: fixed;
    left: 0;
    top: 0;
    z-index: 20;
    box-shadow: var(--shadow-md);
    transition: var(--transition-normal);
}

.sidebar-header {
    height: var(--header-height);
    display: flex;
    align-items: center;
    padding: 0 20px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.sidebar-header h2 {
    font-size: 1.25rem;
    font-weight: 600;
    color: white;
    margin: 0;
}

.sidebar-header .logo {
    display: flex;
    align-items: center;
    gap: 10px;
    color: white;
    text-decoration: none;
}

.sidebar-header .logo i {
    font-size: 1.5rem;
    color: var(--primary-color);
}

.sidebar nav {
    padding: 16px 0;
}

.sidebar nav ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.sidebar nav li {
    margin: 4px 0;
}

.sidebar nav li a {
    display: flex;
    align-items: center;
    padding: 12px 20px;
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: var(--transition-normal);
    border-left: 3px solid transparent;
    font-size: 0.9rem;
}

.sidebar nav li a i {
    margin-right: 12px;
    font-size: 1.1rem;
}

.sidebar nav li a:hover {
    background-color: rgba(255, 255, 255, 0.05);
    color: white;
}

.sidebar nav li a.active {
    background-color: var(--sidebar-active);
    color: white;
    border-left: 3px solid var(--primary-color);
}

/* Main Content Styles */
.main-content {
    margin-left: var(--sidebar-width);
    padding-top: var(--header-height);
    height: 100vh;
    overflow-y: auto;
    width: calc(100% - var(--sidebar-width));
    transition: var(--transition-normal);
}

main {
    padding: 24px;
}

.content-section {
    display: none;
    animation: fadeIn 0.3s ease;
}

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

.content-section.active {
    display: block;
}

/* Card Styles */
.card {
    background-color: var(--card-bg-color);
    border-radius: var(--border-radius);
    padding: 24px;
    margin-bottom: 24px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    transition: var(--transition-normal);
}

.card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.card h3 {
    margin-top: 0;
    margin-bottom: 16px;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--secondary-color);
    display: flex;
    align-items: center;
    transition: color 0.3s ease;
}

.card h3 i {
    margin-right: 8px;
    color: var(--primary-color);
}

/* Form Styles */
.form-group {
    margin-bottom: 1.25rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    font-size: 0.9rem;
    color: var(--text-color);
    transition: color 0.3s ease;
}

input[type="text"],
input[type="file"],
input[type="number"],
input[type="url"],
select,
textarea {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    box-sizing: border-box;
    font-size: 0.9rem;
    transition: var(--transition-normal);
    background-color: var(--card-bg-color);
    color: var(--text-color);
}

input[type="text"]:focus,
input[type="file"]:focus,
input[type="number"]:focus,
input[type="url"]:focus,
select:focus,
textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(62, 99, 221, 0.15);
}

.dark-theme input[type="text"],
.dark-theme input[type="file"],
.dark-theme input[type="number"],
.dark-theme input[type="url"],
.dark-theme select,
.dark-theme textarea {
    background-color: #2D3748;
    border-color: var(--border-color);
    color: var(--text-color);
}

.dark-theme input[type="text"]:focus,
.dark-theme input[type="file"]:focus,
.dark-theme input[type="number"]:focus,
.dark-theme input[type="url"]:focus,
.dark-theme select:focus,
.dark-theme textarea:focus {
    box-shadow: 0 0 0 3px rgba(79, 116, 255, 0.25);
}

input[type="range"] {
    -webkit-appearance: none;
    width: 100%;
    height: 6px;
    border-radius: 3px;
    background: #e2e8f0;
    outline: none;
}

.dark-theme input[type="range"] {
    background: #4A5568;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
}

button {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 10px 16px;
    border-radius: 6px;
    cursor: pointer;
    transition: var(--transition-normal);
    font-weight: 500;
    font-size: 0.9rem;
    display: inline-flex;
    align-items: center;
    position: relative;
    overflow: hidden;
}

button::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 5px;
    height: 5px;
    background: rgba(255, 255, 255, 0.5);
    opacity: 0;
    border-radius: 100%;
    transform: scale(1, 1) translate(-50%);
    transform-origin: 50% 50%;
}

button:focus:not(:active)::after {
    animation: ripple 0.6s ease-out;
}

@keyframes ripple {
    0% {
        transform: scale(0, 0);
        opacity: 0.5;
    }
    100% {
        transform: scale(20, 20);
        opacity: 0;
    }
}

button i {
    margin-right: 8px;
}

button:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
}

button.secondary {
    background-color: transparent;
    color: var(--text-color);
    border: 1px solid var(--border-color);
}

button.secondary:hover {
    background-color: var(--background-color);
}

.dark-theme button.secondary {
    color: var(--text-color);
    border-color: var(--border-color);
}

.dark-theme button.secondary:hover {
    background-color: rgba(255, 255, 255, 0.05);
}

button.danger {
    background-color: var(--danger-color);
}

button.danger:hover {
    background-color: #be123c;
}

.button-group {
    display: flex;
    gap: 12px;
}

/* Table Styles */
.table-container {
    overflow-x: auto;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    transition: border-color 0.3s ease;
}

table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

th, td {
    padding: 12px 16px;
    text-align: left;
    transition: background-color 0.3s ease, color 0.3s ease;
}

th {
    background-color: var(--background-color);
    font-weight: 600;
    color: var(--text-color);
    white-space: nowrap;
}

td {
    border-top: 1px solid var(--border-color);
    color: var(--text-color);
}

tr:hover td {
    background-color: var(--primary-light);
}

/* Actions and Layout Helpers */
.kb-list-actions {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.kb-list-actions .form-group {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 0;
}

.section-header {
    margin-bottom: 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.section-header h2 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--secondary-color);
    margin: 0;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: color 0.3s ease;
}

.section-header h2 i {
    color: var(--primary-color);
}

/* Chat Styles */
#chat-window {
    display: flex;
    flex-direction: column;
    height: 600px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    overflow: hidden;
    background-color: var(--card-bg-color);
    box-shadow: var(--shadow-sm);
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

#chat-history {
    flex-grow: 1;
    padding: 20px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
}

#chat-input-container {
    display: flex;
    border-top: 1px solid var(--border-color);
    padding: 12px;
    background-color: var(--background-color);
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

#chat-input {
    flex-grow: 1;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 12px;
    resize: none;
    font-size: 0.95rem;
    margin-right: 12px;
    height: 50px;
    max-height: 150px;
    background-color: var(--card-bg-color);
    color: var(--text-color);
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

#chat-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(62, 99, 221, 0.15);
}

#chat-send-btn {
    height: 50px;
    width: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0;
}

#chat-send-btn i {
    margin: 0;
    font-size: 1.2rem;
}

.chat-message {
    margin-bottom: 20px;
    max-width: 80%;
    padding: 0;
    display: flex;
    flex-direction: column;
}

.chat-message .message-header {
    font-size: 0.8rem;
    margin-bottom: 4px;
    color: var(--text-light-color);
}

.message-content {
    padding: 12px 16px;
    border-radius: 12px;
    position: relative;
    line-height: 1.6;
}

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

.user-message .message-content {
    background-color: var(--primary-color);
    color: white;
    border-bottom-right-radius: 4px;
}

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

.assistant-message .message-content {
    background-color: var(--background-color);
    color: var(--text-color);
    border-bottom-left-radius: 4px;
}

.dark-theme .assistant-message .message-content {
    background-color: #2D3748;
}

/* Search Results */
#search-results .result-item {
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 16px;
    margin-bottom: 16px;
    background-color: var(--card-bg-color);
    transition: var(--transition-normal);
}

#search-results .result-item:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
}

#search-results .result-item h4 {
    margin-top: 0;
    margin-bottom: 8px;
    color: var(--secondary-color);
    font-size: 0.95rem;
    font-weight: 600;
    display: flex;
    justify-content: space-between;
    transition: color 0.3s ease;
}

#search-results .result-item .score {
    color: var(--text-light-color);
    font-weight: normal;
    font-size: 0.85rem;
}

#search-results .result-item p {
    white-space: pre-wrap;
    margin: 0;
    font-size: 0.9rem;
    line-height: 1.5;
    color: var(--text-color);
    transition: color 0.3s ease;
}

/* Progress Bar */
.progress-container {
    width: 100%;
    background-color: var(--background-color);
    border-radius: 4px;
    overflow: hidden;
    margin-top: 1rem;
    height: 8px;
    transition: background-color 0.3s ease;
}

.progress-bar {
    width: 0%;
    height: 100%;
    background-color: var(--primary-color);
    transition: width 0.4s ease;
}

.upload-status {
    margin-top: 12px;
    font-size: 0.9rem;
    color: var(--text-light-color);
    transition: color 0.3s ease;
}

/* Checkbox and Radio Styles */
.checkbox-group {
    display: flex;
    align-items: center;
    gap: 8px;
}

.checkbox-group input[type="checkbox"] {
    width: 16px;
    height: 16px;
    accent-color: var(--primary-color);
}

/* App Grid Styles */
.app-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 20px;
}

.app-card {
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    overflow: hidden;
    transition: var(--transition-normal);
    background-color: var(--card-bg-color);
    height: 100%;
    display: flex;
    flex-direction: column;
}

.app-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
}

.app-header {
    padding: 16px;
    background-color: var(--background-color);
    border-bottom: 1px solid var(--border-color);
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

.app-header h4 {
    margin: 0;
    font-size: 1rem;
    color: var(--secondary-color);
    display: flex;
    align-items: center;
    gap: 8px;
    transition: color 0.3s ease;
}

.app-header h4 i {
    color: var(--primary-color);
}

.app-body {
    padding: 16px;
    flex-grow: 1;
}

.app-description {
    font-size: 0.9rem;
    color: var(--text-light-color);
    margin-bottom: 16px;
    line-height: 1.5;
    transition: color 0.3s ease;
}

.app-footer {
    padding: 12px 16px;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    background-color: var(--background-color);
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

.app-footer a {
    color: var(--text-color);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 4px;
    font-size: 0.9rem;
    transition: color 0.3s ease;
}

.app-footer a:hover {
    color: var(--primary-color);
}

.app-actions {
    display: flex;
    gap: 8px;
}

.app-form {
    margin-bottom: 24px;
}

.app-form .form-row {
    display: flex;
    gap: 12px;
    margin-bottom: 16px;
}

.app-form .form-row .form-group {
    flex: 1;
    margin-bottom: 0;
}

/* Toast Notification */
.toast-container {
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 1000;
}

.toast {
    background-color: var(--card-bg-color);
    border-left: 4px solid var(--primary-color);
    border-radius: 4px;
    box-shadow: var(--shadow-md);
    padding: 12px 16px;
    margin-top: 8px;
    min-width: 250px;
    max-width: 350px;
    display: flex;
    align-items: center;
    animation: slideIn 0.3s ease, fadeOut 0.5s ease 2.5s forwards;
    transition: background-color 0.3s ease;
}

.toast.success {
    border-left-color: var(--success-color);
}

.toast.error {
    border-left-color: var(--danger-color);
}

.toast.warning {
    border-left-color: var(--warning-color);
}

.toast-icon {
    margin-right: 12px;
    font-size: 1.2rem;
    color: var(--primary-color);
}

.toast.success .toast-icon {
    color: var(--success-color);
}

.toast.error .toast-icon {
    color: var(--danger-color);
}

.toast.warning .toast-icon {
    color: var(--warning-color);
}

.toast-content {
    flex-grow: 1;
}

.toast-message {
    margin: 0;
    font-size: 0.9rem;
    color: var(--text-color);
    transition: color 0.3s ease;
}

@keyframes slideIn {
    from { transform: translateX(100%); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

@keyframes fadeOut {
    from { opacity: 1; }
    to { opacity: 0; }
}

/* Responsive Design */
@media (max-width: 992px) {
    :root {
        --sidebar-width: 70px;
    }
    
    .sidebar-header h2, .sidebar nav li a span {
        display: none;
    }
    
    .sidebar nav li a {
        justify-content: center;
        padding: 12px;
    }
    
    .sidebar nav li a i {
        margin-right: 0;
        font-size: 1.2rem;
    }
}

@media (max-width: 768px) {
    .container {
        flex-direction: column;
    }
    
    .sidebar {
        width: 100%;
        height: auto;
        position: static;
    }
    
    .main-content {
        margin-left: 0;
        width: 100%;
        padding-top: 0;
    }
    
    header {
        left: 0;
        position: static;
    }
    
    .kb-list-actions {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
    }
    
    .app-form .form-row {
        flex-direction: column;
    }
}

/* Utility Classes */
.mt-4 {
    margin-top: 1rem;
}

.mb-4 {
    margin-bottom: 1rem;
}

.text-center {
    text-align: center;
}

.flex {
    display: flex;
}

.items-center {
    align-items: center;
}

.justify-between {
    justify-content: space-between;
}

.gap-2 {
    gap: 0.5rem;
}

.gap-4 {
    gap: 1rem;
}

.w-full {
    width: 100%;
}

.text-sm {
    font-size: 0.875rem;
}

.text-xs {
    font-size: 0.75rem;
}

.font-medium {
    font-weight: 500;
}

.text-danger {
    color: var(--danger-color);
}

.text-success {
    color: var(--success-color);
}

.text-warning {
    color: var(--warning-color);
}

.context-container {
    margin-top: 1rem;
    border-top: 1px solid var(--border-color);
    padding-top: 0.5rem;
}

.context-container summary {
    cursor: pointer;
    font-weight: 500;
    color: var(--text-light-color);
    padding: 0.25rem 0;
    outline: none;
    transition: color 0.2s;
}
.context-container summary:hover {
    color: var(--primary-color);
}

.context-list {
    margin-top: 0.5rem;
    padding-left: 1rem;
    border-left: 2px solid var(--border-color);
}

.context-item {
    font-size: 0.85rem;
    margin-bottom: 1rem;
    color: var(--text-light-color);
}
.context-item strong {
    display: block;
    margin-bottom: 0.25rem;
    color: var(--text-color);
    font-weight: 500;
}
.context-item p {
    margin: 0;
    line-height: 1.5;
}

/* --- App Management --- */