/* ===== RESET & BASE ===== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --bg-primary: #0a0a0a;
    --bg-secondary: #0d0d0d;
    --bg-tertiary: #171717;
    --border-color: #262626;
    --text-primary: #ffffff;
    --text-secondary: #c4c4c4;
    --text-muted: #969696;
    --accent-primary: #e5e5e5;
    --accent-beige: #a3a3a3;
    --accent-beige-dark: #737373;
    --accent-blue: #a3a3a3;
    --font-heading: 'Inter', -apple-system, BlinkMacSystemFont, system-ui, sans-serif;
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, system-ui, sans-serif;
    --font-mono: 'JetBrains Mono', ui-monospace, monospace;
    --grid-color: rgba(255, 255, 255, 0.03);
}

/* Light Mode */
[data-theme="light"] {
    --bg-primary: #ffffff;
    --bg-secondary: #f5f5f5;
    --bg-tertiary: #e8e8e8;
    --border-color: #d4d4d4;
    --text-primary: #171717;
    --text-secondary: #525252;
    --text-muted: #737373;
    --accent-primary: #262626;
    --accent-beige: #737373;
    --accent-beige-dark: #a3a3a3;
    --accent-blue: #525252;
    --grid-color: rgba(0, 0, 0, 0.03);
}

html {
    font-size: 16px;
}

body {
    font-family: var(--font-body);
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    line-height: 1.7;
    min-height: 100vh;
    letter-spacing: -0.01em;
}

/* ===== HEADER ===== */
.site-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1.25rem 2rem;
    background: transparent;
    border-bottom: 1px solid var(--border-color);
}

.header-left {
    flex: 1;
}

.header-right {
    flex: 1;
    display: flex;
    justify-content: flex-end;
}

.nav-links {
    display: flex;
    gap: 2.5rem;
    justify-content: center;
}

.nav-link {
    font-family: var(--font-heading);
    font-size: 0.9rem;
    font-weight: 400;
    color: var(--text-secondary);
    text-decoration: none;
    padding: 0.5rem 0;
    transition: color 0.15s ease;
}

.nav-link:hover {
    color: var(--text-primary);
    text-decoration: underline;
    text-underline-offset: 4px;
}

.nav-link.active {
    color: var(--text-primary);
    text-decoration: underline;
    text-underline-offset: 4px;
}

/* Theme Toggle */
.theme-toggle {
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 0.5rem;
    cursor: pointer;
    color: var(--text-secondary);
    transition: color 0.15s ease, border-color 0.15s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle:hover {
    color: var(--text-primary);
    border-color: var(--text-muted);
}

.theme-toggle .sun-icon {
    display: none;
}

.theme-toggle .moon-icon {
    display: block;
}

[data-theme="light"] .theme-toggle .sun-icon {
    display: block;
}

[data-theme="light"] .theme-toggle .moon-icon {
    display: none;
}

/* ===== MAIN CONTAINER ===== */
.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 2rem;
}

/* ===== VIEW MANAGEMENT ===== */
.view {
    display: none;
}

.view.active {
    display: block;
}

/* ===== TYPOGRAPHY ===== */
.main-title {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 500;
    color: var(--text-primary);
    text-align: left;
    margin: 2rem 0 0.5rem 0;
    letter-spacing: -0.02em;
}

#chat-view .main-title {
    margin-bottom: 0.5rem;
    text-align: center;
}

#chat-view .sub-title {
    text-align: center;
    margin-bottom: 2rem;
}

#about-view .main-title,
#archive-view .main-title {
    margin-top: 0.5rem;
    margin-bottom: 1.5rem;
    text-align: center;
}

#archive-view {
    contain: layout;
}

.sub-title {
    font-family: var(--font-body);
    font-size: 0.9rem;
    line-height: 1.6;
    color: var(--text-secondary);
    text-align: left;
    font-style: normal;
    margin-bottom: 2rem;
    min-height: auto;
}

.section-header {
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin: 2rem 0 0.75rem 0;
    letter-spacing: -0.01em;
}

.section-text {
    font-family: var(--font-body);
    font-size: 0.9rem;
    line-height: 1.8;
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.section-list {
    font-family: var(--font-body);
    font-size: 0.9rem;
    line-height: 1.8;
    color: var(--text-secondary);
    margin-left: 1.25rem;
    margin-bottom: 1rem;
}

.section-list li {
    margin-bottom: 0.5rem;
}

.link-blue {
    color: var(--text-primary);
    text-decoration: underline;
    text-underline-offset: 3px;
    text-decoration-color: var(--text-muted);
    transition: text-decoration-color 0.15s ease;
}

.link-blue:hover {
    text-decoration-color: var(--text-primary);
}

/* ===== SYSTEM PROMPT ===== */
.system-prompt-textarea {
    width: 100%;
    min-height: 220px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 1rem;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--text-secondary);
    resize: vertical;
    margin-bottom: 1rem;
    line-height: 1.6;
}

.system-prompt-textarea:focus {
    outline: none;
    border-color: var(--text-muted);
    color: var(--text-primary);
}

.system-prompt-btn {
    margin-bottom: 1rem;
}

.system-prompt-description {
    /* Normal styling like rest of page */
}

/* ===== BUTTONS ===== */
.btn-primary {
    background: var(--text-primary);
    color: var(--bg-primary);
    border: none;
    border-radius: 6px;
    padding: 0.65rem 1.25rem;
    font-family: var(--font-heading);
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: opacity 0.15s ease;
}

.btn-primary:hover {
    opacity: 0.85;
}

.btn-secondary {
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 0.55rem 1.1rem;
    font-family: var(--font-heading);
    font-size: 0.85rem;
    font-weight: 400;
    cursor: pointer;
    transition: all 0.15s ease;
}

.btn-secondary:hover {
    color: var(--text-primary);
    border-color: var(--text-muted);
}

/* ===== CHAT VIEW ===== */
.chat-messages {
    min-height: 20px;
    margin-bottom: 1rem;
}

.user-msg {
    background: var(--bg-tertiary);
    border-left: 2px solid var(--text-muted);
    padding: 1rem 1.25rem;
    border-radius: 0 4px 4px 0;
    margin: 1rem 0;
    font-family: var(--font-body);
    font-size: 0.9rem;
    color: var(--text-primary);
}

.assistant-msg {
    background: var(--bg-tertiary);
    border-left: 2px solid var(--text-secondary);
    padding: 1.25rem;
    border-radius: 0 4px 4px 0;
    margin: 1rem 0;
    font-family: var(--font-body);
    font-size: 0.9rem;
    line-height: 1.8;
    color: var(--text-primary);
}

.sources-toggle {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
}

.sources-btn {
    background: none;
    border: none;
    color: var(--text-muted);
    font-family: var(--font-heading);
    font-size: 0.8rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: color 0.15s ease;
}

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

.sources-list {
    margin-top: 0.75rem;
    display: none;
}

.sources-list.open {
    display: block;
}

.source-item {
    padding: 0.65rem;
    background: var(--bg-secondary);
    border-radius: 4px;
    margin-bottom: 0.4rem;
    border: 1px solid var(--border-color);
}

.source-title {
    font-family: var(--font-heading);
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.source-number {
    color: var(--text-muted);
    font-weight: 600;
    margin-right: 0.25rem;
}

.source-relevance {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    color: var(--text-muted);
}

.source-excerpt {
    font-family: var(--font-body);
    font-size: 0.8rem;
    color: var(--text-muted);
    font-style: italic;
    margin-top: 0.25rem;
}

.source-clickable {
    cursor: pointer;
    transition: all 0.15s ease;
}

.source-clickable:hover {
    border-color: var(--text-muted);
}

.rag-info-text {
    font-family: var(--font-body);
    font-size: 0.8rem;
    color: var(--text-muted);
    padding: 0.65rem 1rem;
    margin: 0.5rem 0;
    background: var(--bg-tertiary);
    border-radius: 4px;
    text-align: center;
    font-style: italic;
}

.highlight-source {
    background: rgba(115, 115, 115, 0.3);
    padding: 0.1rem 0.25rem;
    border-radius: 2px;
}

.sources-close-btn {
    background: none;
    border: none;
    color: var(--text-muted);
    font-family: var(--font-heading);
    font-size: 0.8rem;
    cursor: pointer;
    margin-top: 0.75rem;
    padding: 0;
    display: block;
    text-align: left;
    transition: color 0.15s ease;
}

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

.chat-input-container {
    display: flex;
    gap: 0.75rem;
    margin-bottom: 2rem;
}

.chat-input {
    flex: 1;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 0.85rem 1rem;
    font-family: var(--font-body);
    font-size: 0.9rem;
    color: var(--text-primary);
    outline: none;
    transition: border-color 0.15s ease;
}

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

.chat-input:focus {
    border-color: var(--text-muted);
}

.sample-questions {
    margin-bottom: 2rem;
}

.sample-title {
    font-family: var(--font-heading);
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
    text-transform: lowercase;
}

.sample-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.5rem;
}

@media (max-width: 768px) {
    .sample-grid {
        grid-template-columns: 1fr;
    }
}

.sample-btn {
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 0.75rem 1rem;
    font-family: var(--font-body);
    font-size: 0.85rem;
    color: var(--text-secondary);
    text-align: left;
    cursor: pointer;
    transition: all 0.15s ease;
}

.sample-btn:hover {
    color: var(--text-primary);
    border-color: var(--text-muted);
}

.chat-actions {
    text-align: center;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
    display: none;
}

.loading-inline {
    display: flex;
    align-items: center;
    gap: 0.65rem;
    padding: 1rem 1.25rem;
    color: var(--text-muted);
    font-family: var(--font-body);
    font-size: 0.85rem;
}

.loading-inline .spinner-small {
    width: 16px;
    height: 16px;
    border: 2px solid var(--border-color);
    border-top-color: var(--text-muted);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

/* ===== ARCHIVE VIEW ===== */
.archive-filters {
    display: flex;
    gap: 1rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

.filter-select, .filter-input {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 0.5rem 0.75rem;
    font-family: var(--font-heading);
    font-size: 0.8rem;
    color: var(--text-secondary);
    outline: none;
    transition: border-color 0.15s ease;
}

.filter-select:focus, .filter-input:focus {
    border-color: var(--text-muted);
    color: var(--text-primary);
}

.filter-select {
    min-width: 130px;
}

.filter-input {
    flex: 1;
    min-width: 180px;
}

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

.doc-count {
    font-family: var(--font-heading);
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-bottom: 1rem;
}

.archive-layout {
    display: grid;
    grid-template-columns: 1fr 3fr;
    gap: 1.5rem;
    height: calc(100vh - 300px);
}


@media (max-width: 900px) {
    .archive-layout {
        grid-template-columns: 1fr;
    }
}

.doc-list {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    height: 100%;
    min-height: 100%;
    overflow-y: auto;
    padding-right: 0.5rem;
}

.doc-list-item {
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 0.6rem 0.85rem;
    font-family: var(--font-heading);
    font-size: 0.75rem;
    color: var(--text-secondary);
    cursor: pointer;
    text-align: left;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    flex-shrink: 0;
    transition: all 0.15s ease;
}

.doc-list-item:hover {
    color: var(--text-primary);
    border-color: var(--text-muted);
}

.doc-list-item.active {
    border-color: var(--text-secondary);
    color: var(--text-primary);
    background: var(--bg-tertiary);
}

.doc-viewer {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    overflow: hidden;
    height: 100%;
}

.doc-viewer-inner {
    padding: 1.5rem;
    height: 100%;
    overflow-y: auto;
    contain: strict;
}

.doc-viewer-placeholder {
    text-align: center;
    color: var(--text-secondary);
    font-style: italic;
    padding: 2rem;
}

.doc-viewer-header {
    margin-bottom: 1rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.doc-viewer-title {
    font-family: var(--font-heading);
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.doc-viewer-meta {
    font-family: var(--font-heading);
    font-size: 0.75rem;
    color: var(--text-muted);
}

.doc-viewer-content {
    font-family: var(--font-body);
    font-size: 0.9rem;
    line-height: 1.8;
    color: var(--text-primary);
    overflow-wrap: break-word;
}

.doc-viewer-content h1,
.doc-viewer-content h2,
.doc-viewer-content h3 {
    font-family: var(--font-heading);
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.doc-viewer-content h1 { font-size: 1.25rem; font-weight: 500; }
.doc-viewer-content h2 { font-size: 1.1rem; font-weight: 500; }
.doc-viewer-content h3 { font-size: 0.95rem; font-weight: 500; }

.doc-viewer-content p {
    margin-bottom: 1rem;
}

.doc-viewer-content ul,
.doc-viewer-content ol {
    margin-left: 1.25rem;
    margin-bottom: 1rem;
}

.doc-viewer-content blockquote {
    border-left: 2px solid var(--text-muted);
    padding-left: 1rem;
    margin: 1rem 0;
    color: var(--text-muted);
    font-style: italic;
}

.doc-viewer-content code {
    font-family: var(--font-mono);
    background: var(--bg-secondary);
    padding: 0.15rem 0.35rem;
    border-radius: 3px;
    font-size: 0.85rem;
}

.doc-viewer-content pre {
    background: var(--bg-secondary);
    padding: 1rem;
    border-radius: 4px;
    overflow-x: auto;
    margin-bottom: 1rem;
}

.doc-viewer-content pre code {
    background: none;
    padding: 0;
}

/* Contain KaTeX math rendering */
.doc-viewer-content .katex-display {
    overflow-x: auto;
    overflow-y: hidden;
    max-width: 100%;
}

.doc-viewer-content .katex {
    max-width: 100%;
}

.doc-download-btn {
    margin-top: 1rem;
}

.source-collection-info {
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.source-collection-header {
    font-family: var(--font-heading);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.source-collection-text {
    font-family: var(--font-body);
    font-size: 0.85rem;
    line-height: 1.7;
    color: var(--text-secondary);
}

.source-collection-list {
    list-style: disc;
    margin: 0.75rem 0 0 1.25rem;
    padding: 0;
}

.source-collection-list li {
    font-family: var(--font-body);
    font-size: 0.85rem;
    line-height: 1.7;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
}

.source-collection-list li:last-child {
    margin-bottom: 0;
}

/* ===== LOADING ===== */
.loading {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(10, 10, 10, 0.85);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.loading.hidden {
    display: none;
}

.spinner {
    width: 32px;
    height: 32px;
    border: 2px solid var(--border-color);
    border-top-color: var(--text-secondary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* ===== SCROLLBAR ===== */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

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

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

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
    .site-header {
        padding: 1rem;
    }

    .nav-links {
        gap: 1rem;
    }

    .nav-link {
        font-size: 0.8rem;
    }

    .header-left {
        display: none;
    }

    .header-right {
        flex: 0;
    }

    .container {
        padding: 1rem;
    }

    .main-title {
        font-size: 2rem;
    }
}