/* ==========================================================================
   Antigravity Documentation Common Design System & Theme Styles
   Used across index.html (Code Walkthrough) and brain.html (Brain Specification)
   ========================================================================== */

:root {
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-mono: 'JetBrains Mono', SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    
    /* Dark Theme (Default) */
    --bg-page: #0d1117;
    --bg-card: #161b22;
    --bg-card-header: #21262d;
    --bg-sidebar: #0d1117;
    --border-color: #30363d;
    --border-focus: #58a6ff;
    
    --text-main: #c9d1d9;
    --text-heading: #f0f6fc;
    --text-muted: #8b949e;
    --text-dim: #6e7681;
    
    --accent-primary: #58a6ff;
    --accent-primary-hover: #79b8ff;
    --accent-gradient: linear-gradient(135deg, #58a6ff 0%, #bc8cff 100%);
    --accent-purple: #bc8cff;
    --accent-green: #3fb950;
    --accent-amber: #d29922;
    --accent-rose: #f85149;
    
    --code-bg: #0b0e14;
    --code-gutter-bg: #090c10;
    --code-gutter-text: #484f58;
    --badge-bg: rgba(56, 139, 253, 0.15);
    --badge-border: rgba(56, 139, 253, 0.4);
    --badge-text: #58a6ff;
    
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.4);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.5);
    --shadow-lg: 0 12px 28px rgba(0,0,0,0.6);
}

[data-theme="light"] {
    --bg-page: #f6f8fa;
    --bg-card: #ffffff;
    --bg-card-header: #f6f8fa;
    --bg-sidebar: #ffffff;
    --border-color: #d0d7de;
    --border-focus: #0969da;
    
    --text-main: #24292f;
    --text-heading: #1f2328;
    --text-muted: #57606a;
    --text-dim: #8c959f;
    
    --accent-primary: #0969da;
    --accent-primary-hover: #218bff;
    --accent-gradient: linear-gradient(135deg, #0969da 0%, #8250df 100%);
    --accent-purple: #8250df;
    --accent-green: #1a7f37;
    --accent-amber: #9a6700;
    --accent-rose: #cf222e;
    
    --code-bg: #f6f8fa;
    --code-gutter-bg: #eaeef2;
    --code-gutter-text: #8c959f;
    --badge-bg: rgba(9, 105, 218, 0.1);
    --badge-border: rgba(9, 105, 218, 0.3);
    --badge-text: #0969da;
    
    --shadow-sm: 0 1px 3px rgba(31,35,40,0.12);
    --shadow-md: 0 4px 12px rgba(31,35,40,0.1);
    --shadow-lg: 0 12px 24px rgba(31,35,40,0.15);
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: var(--font-sans);
    background-color: var(--bg-page);
    color: var(--text-main);
    line-height: 1.65;
    font-size: 15px;
    transition: background-color 0.25s ease, color 0.25s ease;
}

/* ==========================================================================
   Reading Progress Bar
   ========================================================================== */
#progress-bar {
    position: fixed;
    top: 0;
    left: 0;
    height: 3px;
    width: 0%;
    background: var(--accent-gradient);
    z-index: 1000;
    transition: width 0.1s ease-out;
}

/* ==========================================================================
   App Header & Brand Bar
   ========================================================================== */
.app-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(13, 17, 23, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    transition: background-color 0.25s ease, border-color 0.25s ease;
}
[data-theme="light"] .app-header {
    background: rgba(255, 255, 255, 0.88);
}

.header-container {
    max-width: 1480px;
    margin: 0 auto;
    padding: 12px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.brand-group {
    display: flex;
    align-items: center;
    gap: 12px;
}

.brand-logo {
    width: 34px;
    height: 34px;
    border-radius: 8px;
    background: var(--accent-gradient);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 800;
    font-size: 16px;
    box-shadow: 0 2px 8px rgba(88, 166, 255, 0.3);
}

.brand-text h1 {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--text-heading);
    letter-spacing: -0.01em;
}
.brand-text p {
    font-size: 0.78rem;
    color: var(--text-muted);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 12px;
}

.badge-pill {
    font-family: var(--font-mono);
    font-size: 0.74rem;
    padding: 4px 10px;
    border-radius: 999px;
    background: var(--badge-bg);
    border: 1px solid var(--badge-border);
    color: var(--badge-text);
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.nav-btn-link {
    text-decoration: none;
    color: var(--text-main);
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 7px 12px;
    border-radius: 8px;
    font-size: 0.84rem;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    transition: all 0.2s ease;
}
.nav-btn-link:hover {
    border-color: var(--accent-primary);
    color: var(--accent-primary);
    background: var(--bg-card-header);
}

.theme-toggle-btn {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-main);
    padding: 7px 12px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.85rem;
    display: flex;
    align-items: center;
    gap: 6px;
    transition: all 0.2s;
}
.theme-toggle-btn:hover {
    border-color: var(--border-focus);
    color: var(--accent-primary);
}

/* ==========================================================================
   Hero Banner
   ========================================================================== */
.hero-banner {
    max-width: 1480px;
    margin: 0 auto;
    padding: 36px 24px 20px 24px;
}

.hero-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 14px;
    padding: 32px;
    box-shadow: var(--shadow-md);
    position: relative;
    overflow: hidden;
}

.hero-card::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--accent-gradient);
}

.hero-title {
    font-size: 1.85rem;
    font-weight: 800;
    color: var(--text-heading);
    margin-bottom: 12px;
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: 1.05rem;
    color: var(--text-muted);
    max-width: 900px;
    margin-bottom: 24px;
    line-height: 1.6;
}

.hero-stats {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
}

.stat-item {
    background: var(--bg-page);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 10px 18px;
    display: flex;
    flex-direction: column;
    gap: 2px;
}
.stat-val {
    font-family: var(--font-mono);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-heading);
}
.stat-lbl {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 600;
}

/* ==========================================================================
   Layout Grid & Sidebar
   ========================================================================== */
.main-layout {
    max-width: 1480px;
    margin: 0 auto;
    padding: 24px;
    display: grid;
    grid-template-columns: 310px 1fr;
    gap: 32px;
    align-items: start;
}

.sidebar {
    position: sticky;
    top: 90px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 16px;
    box-shadow: var(--shadow-sm);
    max-height: calc(100vh - 120px);
    overflow-y: auto;
}

.sidebar-title {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-dim);
    font-weight: 700;
    padding: 4px 8px 12px 8px;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 10px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-list {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.nav-item, .nav-link {
    display: flex;
    align-items: baseline;
    gap: 10px;
    padding: 8px 10px;
    border-radius: 8px;
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.84rem;
    line-height: 1.4;
    transition: all 0.15s ease;
}

.nav-item:hover, .nav-link:hover {
    background: var(--bg-card-header);
    color: var(--text-heading);
}

.nav-item.active, .nav-link.active {
    background: var(--badge-bg);
    color: var(--accent-primary);
    font-weight: 600;
}

.nav-num {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    opacity: 0.7;
    flex-shrink: 0;
}

.nav-label {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* ==========================================================================
   Content Stream & Section Cards
   ========================================================================== */
.content-stream {
    display: flex;
    flex-direction: column;
    gap: 48px;
    min-width: 0;
}

.content-section, .spec-section {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 14px;
    padding: 30px;
    box-shadow: var(--shadow-sm);
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.content-section:hover, .spec-section:hover {
    border-color: rgba(88, 166, 255, 0.4);
    box-shadow: var(--shadow-md);
}

.section-header {
    margin-bottom: 22px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 16px;
}

.badge-row {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 8px;
}

.category-badge {
    font-size: 0.72rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 3px 8px;
    border-radius: 6px;
    background: var(--badge-bg);
    border: 1px solid var(--badge-border);
    color: var(--badge-text);
}

.lines-badge {
    font-family: var(--font-mono);
    font-size: 0.74rem;
    color: var(--text-dim);
}

.section-title {
    font-size: 1.45rem;
    font-weight: 700;
    color: var(--text-heading);
    letter-spacing: -0.01em;
}

/* ==========================================================================
   Prose, Explanations & Notes
   ========================================================================== */
.prose {
    font-size: 0.98rem;
    line-height: 1.7;
    color: var(--text-main);
    margin-bottom: 20px;
}
.prose p {
    margin-bottom: 12px;
}
.prose p:last-child {
    margin-bottom: 0;
}

.explanation-box {
    margin-bottom: 26px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.prose-intro p {
    font-size: 0.98rem;
    line-height: 1.68;
    color: var(--text-main);
    margin-bottom: 10px;
}
.prose-intro p:last-child {
    margin-bottom: 0;
}

.prose-deep-dive {
    background: var(--bg-card-header);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 20px 24px;
    font-size: 0.92rem;
    line-height: 1.65;
    margin: 20px 0;
}

.prose-deep-dive h4 {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--text-heading);
    margin-bottom: 12px;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.prose-deep-dive ul, .prose-deep-dive ol {
    padding-left: 20px;
    margin-bottom: 12px;
}

.prose-deep-dive li {
    margin-bottom: 8px;
    color: var(--text-main);
}
.prose-deep-dive li:last-child {
    margin-bottom: 0;
}

/* Inline Code Elements */
code {
    font-family: var(--font-mono);
    font-size: 0.86em;
    padding: 2px 6px;
    border-radius: 4px;
    background: var(--code-bg);
    border: 1px solid var(--border-color);
    color: var(--accent-purple);
}
[data-theme="light"] code {
    background: rgba(175, 184, 193, 0.25);
    border-color: rgba(208, 215, 222, 0.5);
    color: #6f42c1;
}

/* Callouts & Alert Cards */
.note-card, .alert-box {
    margin: 16px 0;
    padding: 14px 18px;
    border-radius: 8px;
    display: flex;
    gap: 12px;
    font-size: 0.88rem;
    line-height: 1.55;
    align-items: flex-start;
}

.note-card.info, .alert-box.info {
    background: rgba(56, 139, 253, 0.08);
    border: 1px solid rgba(56, 139, 253, 0.25);
    color: var(--text-main);
}

.note-card.success, .alert-box.tip {
    background: rgba(63, 185, 80, 0.08);
    border: 1px solid rgba(63, 185, 80, 0.25);
    color: var(--text-main);
}

.note-card.warning, .alert-box.warning {
    background: rgba(210, 153, 34, 0.08);
    border: 1px solid rgba(210, 153, 34, 0.25);
    color: var(--text-main);
}

.note-icon, .alert-icon {
    font-size: 1.1rem;
    flex-shrink: 0;
    line-height: 1;
    margin-top: 2px;
}

/* ==========================================================================
   Code Containers & Highlighting
   ========================================================================== */
.code-container {
    background: var(--code-bg);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    overflow: hidden;
    margin: 18px 0;
    box-shadow: inset 0 1px 3px rgba(0,0,0,0.3);
}

.code-header {
    background: var(--bg-card-header);
    border-bottom: 1px solid var(--border-color);
    padding: 10px 16px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.code-header-left {
    display: flex;
    align-items: center;
    gap: 10px;
}

.file-tag {
    font-family: var(--font-mono);
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--accent-primary);
}

.line-range {
    font-family: var(--font-mono);
    font-size: 0.74rem;
    color: var(--text-dim);
}

.copy-btn {
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 4px 10px;
    color: var(--text-muted);
    cursor: pointer;
    font-family: var(--font-sans);
    font-size: 0.75rem;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 6px;
    transition: all 0.2s;
}

.copy-btn:hover {
    background: var(--bg-page);
    border-color: var(--border-focus);
    color: var(--text-heading);
}

.copy-btn.copied {
    border-color: var(--accent-green);
    color: var(--accent-green);
}

/* Code viewport for line-by-line tables */
.code-viewport {
    width: 100%;
    overflow-x: auto;
    background: var(--code-bg);
}

.code-table {
    display: table;
    width: 100%;
    table-layout: auto;
    border-collapse: collapse;
    font-family: var(--font-mono);
    font-size: 13.5px;
    line-height: 22px;
}

.code-line {
    display: table-row;
    transition: background-color 0.1s ease;
}

.code-line:hover {
    background-color: rgba(56, 139, 253, 0.08);
}

.code-line.target-highlight {
    background-color: rgba(188, 140, 255, 0.18) !important;
}

.line-num {
    display: table-cell;
    vertical-align: top;
    width: 48px;
    min-width: 48px;
    max-width: 48px;
    padding: 0 16px 0 12px;
    text-align: right;
    color: var(--code-gutter-text);
    background: var(--code-gutter-bg);
    border-right: 1px solid var(--border-color);
    user-select: none;
    cursor: pointer;
    font-size: 12px;
}

.code-line:hover .line-num {
    color: var(--text-muted);
}

.line-code {
    display: table-cell;
    vertical-align: top;
    padding: 0 16px;
    white-space: pre;
    color: var(--text-main);
}

/* Pre / Code default block overrides */
pre[class*="language-"] {
    margin: 0 !important;
    padding: 16px !important;
    background: transparent !important;
    font-family: var(--font-mono) !important;
    font-size: 0.85rem !important;
    line-height: 1.6 !important;
    overflow-x: auto;
}

/* ==========================================================================
   Data & Specification Tables
   ========================================================================== */
.spec-table-container {
    width: 100%;
    overflow-x: auto;
    margin: 18px 0;
    border: 1px solid var(--border-color);
    border-radius: 8px;
}

.spec-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.88rem;
    text-align: left;
}

.spec-table th {
    background: var(--bg-card-header);
    color: var(--text-heading);
    font-weight: 600;
    padding: 10px 14px;
    border-bottom: 1px solid var(--border-color);
}

.spec-table td {
    padding: 10px 14px;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-main);
    vertical-align: top;
}

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

.spec-table tr:hover td {
    background: rgba(255, 255, 255, 0.02);
}
[data-theme="light"] .spec-table tr:hover td {
    background: rgba(0, 0, 0, 0.02);
}

/* ==========================================================================
   Page-Specific Component: Interactive File Tree (brain.html)
   ========================================================================== */
.interactive-tree-grid {
    display: grid;
    grid-template-columns: 320px 1fr;
    gap: 20px;
    margin: 20px 0;
    border: 1px solid var(--border-color);
    border-radius: 10px;
    background: var(--code-bg);
    padding: 18px;
}

.tree-view {
    font-family: var(--font-mono);
    font-size: 0.84rem;
    display: flex;
    flex-direction: column;
    gap: 4px;
    border-right: 1px solid var(--border-color);
    padding-right: 14px;
}

.tree-node {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 6px 10px;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.15s ease;
    color: var(--text-muted);
    user-select: none;
}

.tree-node:hover {
    background: var(--bg-card-header);
    color: var(--text-heading);
}

.tree-node.selected {
    background: var(--badge-bg);
    color: var(--accent-primary);
    font-weight: 600;
}

.tree-node.depth-1 { margin-left: 18px; }
.tree-node.depth-2 { margin-left: 36px; }
.tree-node.depth-3 { margin-left: 54px; }

.tree-icon {
    font-size: 0.95rem;
}

.tree-desc-panel {
    padding: 8px 12px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.tree-desc-title {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--text-heading);
    font-family: var(--font-mono);
    display: flex;
    align-items: center;
    gap: 8px;
}

.tree-desc-body {
    font-size: 0.9rem;
    color: var(--text-main);
    line-height: 1.6;
}

.tree-desc-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    font-size: 0.78rem;
    font-family: var(--font-mono);
    color: var(--text-dim);
}

/* ==========================================================================
   Footer & Floating Back to Top
   ========================================================================== */
.app-footer, .page-footer {
    max-width: 1480px;
    margin: 60px auto 40px auto;
    padding: 24px;
    text-align: center;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.85rem;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-top: 12px;
}

.footer-links a, .page-footer a {
    color: var(--accent-primary);
    text-decoration: none;
}
.footer-links a:hover, .page-footer a:hover {
    text-decoration: underline;
}

#back-to-top {
    position: fixed;
    bottom: 24px;
    right: 24px;
    width: 42px;
    height: 42px;
    border-radius: 50%;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-main);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: var(--shadow-md);
    opacity: 0;
    pointer-events: none;
    transition: all 0.25s ease;
    z-index: 90;
}
#back-to-top.visible {
    opacity: 1;
    pointer-events: auto;
}
#back-to-top:hover {
    background: var(--bg-card-header);
    border-color: var(--border-focus);
    color: var(--accent-primary);
    transform: translateY(-2px);
}

/* ==========================================================================
   Responsive Breakpoints
   ========================================================================== */
@media (max-width: 1080px) {
    .main-layout {
        grid-template-columns: 1fr;
    }
    .sidebar {
        position: relative;
        top: 0;
        max-height: none;
        margin-bottom: 24px;
    }
    .interactive-tree-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .hero-title {
        font-size: 1.45rem;
    }
    .hero-card {
        padding: 20px;
    }
    .content-section, .spec-section {
        padding: 18px;
    }
    .section-title {
        font-size: 1.2rem;
    }
}

/* ==========================================================================
   Prism.js Syntax Highlighting Token Palette
   ========================================================================== */
.token.comment, .token.prolog, .token.doctype, .token.cdata {
    color: #8b949e;
    font-style: italic;
}
.token.punctuation {
    color: #d2a8ff;
}
.token.property, .token.tag, .token.boolean, .token.number, .token.constant, .token.symbol, .token.deleted {
    color: #79c0ff;
}
.token.selector, .token.attr-name, .token.string, .token.char, .token.builtin, .token.inserted {
    color: #a5d6ff;
}
.token.operator, .token.entity, .token.url, .language-css .token.string, .style .token.string {
    color: #ff7b72;
}
.token.atrule, .token.attr-value, .token.keyword {
    color: #ff7b72;
    font-weight: 600;
}
.token.function, .token.class-name {
    color: #d2a8ff;
}
.token.regex, .token.important, .token.variable {
    color: #ffa657;
}