/* ==========================================================================
   RNOISE RECORDS / DREAMVFIA UNION — Developer & AI Resource Hub Design System
   Zero Emoji Policy | Inter + JetBrains Mono Typography | Cyber Red & Cyan HSL
   ========================================================================== */

:root {
  --bg-primary: #05070b;
  --bg-secondary: #0a0d14;
  --bg-card: rgba(14, 19, 28, 0.75);
  --bg-card-hover: rgba(20, 27, 40, 0.9);
  --bg-code: #070a0f;
  
  --text-main: #f0f4f8;
  --text-muted: #8e9cae;
  --text-dim: #5c6878;
  
  --brand-red: #ff2a5f;
  --brand-red-glow: rgba(255, 42, 95, 0.35);
  --brand-cyan: #00f3ff;
  --brand-cyan-glow: rgba(0, 243, 255, 0.3);
  --brand-green: #22c55e;
  
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-card: rgba(255, 255, 255, 0.12);
  --border-red: rgba(255, 42, 95, 0.3);
  --border-cyan: rgba(0, 243, 255, 0.3);
  
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: 'JetBrains Mono', "SF Mono", Consolas, "Courier New", monospace;
  
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-pill: 9999px;
  
  --shadow-card: 0 10px 30px rgba(0, 0, 0, 0.4), 0 1px 2px rgba(255, 255, 255, 0.05);
  --shadow-glow: 0 0 25px var(--brand-red-glow);
}

*, *::before, *::after {
  box-sizing: border-box;
}

html {
  background-color: var(--bg-primary);
  color: var(--text-main);
  font-family: var(--font-sans);
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  margin: 0;
  padding: 0;
  line-height: 1.6;
  background: 
    radial-gradient(circle at 15% 10%, rgba(255, 42, 95, 0.09) 0%, transparent 40%),
    radial-gradient(circle at 85% 15%, rgba(0, 243, 255, 0.07) 0%, transparent 40%),
    radial-gradient(circle at 50% 90%, rgba(255, 42, 95, 0.05) 0%, transparent 50%),
    var(--bg-primary);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* --------------------------------------------------------------------------
   Top Sticky Navigation
   -------------------------------------------------------------------------- */
.hub-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(5, 7, 11, 0.82);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--border-subtle);
  padding: 12px 24px;
}

.hub-header-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.hub-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--text-main);
}

.hub-brand-logo {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hub-brand-logo img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.hub-brand-title {
  display: flex;
  flex-direction: column;
}

.hub-brand-name {
  font-size: 14px;
  font-weight: 800;
  letter-spacing: 0.08em;
  color: #ffffff;
  text-transform: uppercase;
}

.hub-brand-sub {
  font-size: 10px;
  font-family: var(--font-mono);
  color: var(--brand-cyan);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.hub-nav-tabs {
  display: flex;
  align-items: center;
  gap: 6px;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-pill);
  padding: 4px;
}

.hub-nav-link {
  font-size: 12px;
  font-family: var(--font-mono);
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  text-decoration: none;
  color: var(--text-muted);
  transition: all 0.2s cubic-bezier(0.34, 1.56, 0.64, 1);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.hub-nav-link:hover {
  color: var(--text-main);
  background: rgba(255, 255, 255, 0.06);
}

.hub-nav-link.active {
  color: #ffffff;
  background: linear-gradient(135deg, rgba(255, 42, 95, 0.25), rgba(0, 243, 255, 0.15));
  border: 1px solid var(--border-red);
  box-shadow: 0 0 15px rgba(255, 42, 95, 0.2);
}

.hub-header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.btn-lang-toggle {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  color: var(--text-main);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  padding: 6px 12px;
  cursor: pointer;
  transition: all 0.2s ease;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.btn-lang-toggle:hover {
  background: rgba(255, 255, 255, 0.09);
  border-color: var(--brand-cyan);
  color: var(--brand-cyan);
}

.btn-home-link {
  color: var(--text-muted);
  font-size: 12px;
  font-family: var(--font-mono);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  transition: all 0.2s ease;
}

.btn-home-link:hover {
  color: #ffffff;
  border-color: var(--border-subtle);
}

/* --------------------------------------------------------------------------
   Breadcrumb
   -------------------------------------------------------------------------- */
.hub-breadcrumb-bar {
  max-width: 1200px;
  margin: 16px auto 0;
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  font-family: var(--font-mono);
  color: var(--text-dim);
}

.hub-breadcrumb-bar a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.15s ease;
}

.hub-breadcrumb-bar a:hover {
  color: var(--brand-cyan);
}

.hub-breadcrumb-sep {
  opacity: 0.4;
}

/* --------------------------------------------------------------------------
   Main Layout & Hero Section
   -------------------------------------------------------------------------- */
.hub-main {
  flex: 1;
  max-width: 1200px;
  width: 100%;
  margin: 0 auto;
  padding: 24px 24px 60px;
}

.hub-hero {
  background: var(--bg-card);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-lg);
  padding: 36px 32px;
  margin-bottom: 32px;
  box-shadow: var(--shadow-card);
  position: relative;
  overflow: hidden;
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 32px;
}

.hub-hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--brand-red), var(--brand-cyan), transparent);
}

.hub-hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: rgba(255, 42, 95, 0.12);
  border: 1px solid var(--border-red);
  color: var(--brand-red);
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 4px 10px;
  border-radius: var(--radius-pill);
  margin-bottom: 12px;
}

.hub-hero-title {
  font-size: clamp(24px, 4vw, 36px);
  font-weight: 800;
  line-height: 1.2;
  margin: 0 0 12px;
  letter-spacing: -0.02em;
  color: #ffffff;
}

.hub-hero-desc {
  font-size: 15px;
  color: var(--text-muted);
  max-width: 720px;
  margin: 0 0 20px;
  line-height: 1.6;
}

.hub-hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 24px;
}

.meta-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 4px 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-muted);
}

.meta-pill-key {
  color: var(--brand-cyan);
}

.hub-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
}

.hub-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.2s cubic-bezier(0.34, 1.56, 0.64, 1);
  border: 1px solid transparent;
}

.hub-btn-primary {
  background: linear-gradient(135deg, #ff2a5f, #ff527b);
  color: #ffffff;
  box-shadow: 0 4px 15px rgba(255, 42, 95, 0.35);
}

.hub-btn-primary:hover {
  box-shadow: 0 6px 20px rgba(255, 42, 95, 0.55);
  transform: translateY(-2px);
}

.hub-btn-secondary {
  background: rgba(255, 255, 255, 0.05);
  border-color: var(--border-card);
  color: var(--text-main);
}

.hub-btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--brand-cyan);
  color: var(--brand-cyan);
  transform: translateY(-2px);
}

.hub-btn-ghost {
  background: transparent;
  color: var(--text-muted);
  border-color: var(--border-subtle);
}

.hub-btn-ghost:hover {
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.25);
}

.hub-hero-asset {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 140px;
  height: 140px;
  flex-shrink: 0;
}

.hub-hero-asset img {
  width: 120px;
  height: 120px;
  object-fit: contain;
  filter: drop-shadow(0 0 20px rgba(0, 243, 255, 0.25));
  animation: floatShape 6s ease-in-out infinite;
}

@keyframes floatShape {
  0%, 100% { transform: translateY(0px) rotate(0deg); }
  50% { transform: translateY(-8px) rotate(3deg); }
}

@media (max-width: 860px) {
  .hub-hero {
    grid-template-columns: 1fr;
    text-align: left;
    padding: 24px 20px;
  }
  .hub-hero-asset {
    display: none;
  }
}

/* --------------------------------------------------------------------------
   Notice & Callout Boxes
   -------------------------------------------------------------------------- */
.hub-callout {
  background: rgba(255, 42, 95, 0.07);
  border: 1px solid var(--border-red);
  border-left: 4px solid var(--brand-red);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  margin-bottom: 28px;
  display: flex;
  gap: 14px;
  align-items: flex-start;
}

.hub-callout.cyan {
  background: rgba(0, 243, 255, 0.06);
  border-color: var(--border-cyan);
  border-left-color: var(--brand-cyan);
}

.hub-callout-icon {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  margin-top: 2px;
  color: var(--brand-red);
}

.hub-callout.cyan .hub-callout-icon {
  color: var(--brand-cyan);
}

.hub-callout-content {
  font-size: 13px;
  color: var(--text-main);
  line-height: 1.55;
}

.hub-callout-title {
  font-weight: 700;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.05em;
  margin-bottom: 4px;
  color: #ffffff;
  text-transform: uppercase;
}

/* --------------------------------------------------------------------------
   Grid Cards & Content Blocks
   -------------------------------------------------------------------------- */
.hub-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
  gap: 20px;
  margin-bottom: 32px;
}

@media (max-width: 600px) {
  .hub-grid {
    grid-template-columns: 1fr;
  }
}

.hub-card {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 22px 24px;
  transition: all 0.25s cubic-bezier(0.34, 1.56, 0.64, 1);
  display: flex;
  flex-direction: column;
}

.hub-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-cyan);
  box-shadow: 0 10px 25px rgba(0, 243, 255, 0.08);
  transform: translateY(-3px);
}

.hub-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
}

.hub-card-badge {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 700;
  padding: 3px 8px;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.05);
  color: var(--brand-cyan);
  border: 1px solid rgba(0, 243, 255, 0.2);
}

.hub-card-icon {
  width: 24px;
  height: 24px;
  color: var(--brand-red);
}

.hub-card-title {
  font-size: 17px;
  font-weight: 700;
  margin: 0 0 8px;
  color: #ffffff;
}

.hub-card-desc {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.55;
  margin: 0 0 16px;
  flex-grow: 1;
}

.hub-card-link-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 12px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  text-decoration: none;
  color: var(--text-main);
  font-size: 13px;
  font-family: var(--font-sans);
  margin-bottom: 8px;
  transition: all 0.2s ease;
}

.hub-card-link-item:hover {
  background: rgba(255, 255, 255, 0.06);
  border-color: var(--brand-cyan);
}

.hub-card-link-item:hover .hub-link-arrow {
  color: var(--brand-cyan);
  transform: translate(2px, -2px);
}

.hub-link-arrow {
  width: 14px;
  height: 14px;
  color: var(--text-dim);
  transition: all 0.2s ease;
  flex-shrink: 0;
}

.hub-link-tag {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--brand-cyan);
  background: rgba(0, 243, 255, 0.08);
  padding: 2px 6px;
  border-radius: 4px;
  margin-left: 6px;
}

/* --------------------------------------------------------------------------
   Knowledge Section (Table of Contents + Reader)
   -------------------------------------------------------------------------- */
.hub-reader-layout {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 28px;
  align-items: flex-start;
}

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

.hub-sidebar-toc {
  position: sticky;
  top: 80px;
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 18px;
  max-height: calc(100vh - 100px);
  overflow-y: auto;
}

.hub-toc-title {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--brand-cyan);
  text-transform: uppercase;
  margin: 0 0 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-subtle);
}

.hub-toc-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.hub-toc-link {
  font-size: 12px;
  color: var(--text-muted);
  text-decoration: none;
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  transition: all 0.15s ease;
  display: block;
  line-height: 1.4;
}

.hub-toc-link:hover {
  color: #ffffff;
  background: rgba(255, 255, 255, 0.05);
}

.hub-toc-link.active {
  color: var(--brand-red);
  background: rgba(255, 42, 95, 0.08);
  border-left: 2px solid var(--brand-red);
}

.hub-reader-content {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow-card);
}

.hub-section-block {
  margin-bottom: 36px;
  padding-bottom: 28px;
  border-bottom: 1px solid var(--border-subtle);
}

.hub-section-block:last-child {
  border-bottom: none;
  margin-bottom: 0;
  padding-bottom: 0;
}

.hub-section-title {
  font-size: 20px;
  font-weight: 700;
  color: #ffffff;
  margin: 0 0 16px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.hub-section-title-num {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--brand-red);
  background: rgba(255, 42, 95, 0.1);
  padding: 2px 8px;
  border-radius: 4px;
  border: 1px solid var(--border-red);
}

/* --------------------------------------------------------------------------
   Data Tables
   -------------------------------------------------------------------------- */
.hub-table-wrapper {
  overflow-x: auto;
  margin: 16px 0;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  background: rgba(5, 7, 11, 0.6);
}

.hub-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
  text-align: left;
}

.hub-table th {
  background: rgba(255, 255, 255, 0.03);
  color: var(--brand-cyan);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.05em;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border-subtle);
  text-transform: uppercase;
}

.hub-table td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border-subtle);
  color: var(--text-main);
}

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

.hub-table tr:hover td {
  background: rgba(255, 255, 255, 0.02);
}

/* --------------------------------------------------------------------------
   Code Block & Terminal Viewer
   -------------------------------------------------------------------------- */
.hub-code-container {
  background: var(--bg-code);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
  margin: 20px 0;
}

.hub-code-header {
  background: rgba(255, 255, 255, 0.03);
  border-bottom: 1px solid var(--border-subtle);
  padding: 10px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.hub-code-dots {
  display: flex;
  align-items: center;
  gap: 6px;
}

.hub-code-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.15);
}

.hub-code-filename {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-muted);
}

.hub-copy-btn {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-subtle);
  border-radius: 4px;
  color: var(--text-main);
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 4px 10px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all 0.2s ease;
}

.hub-copy-btn:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: var(--brand-cyan);
  color: var(--brand-cyan);
}

.hub-code-content {
  margin: 0;
  padding: 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.6;
  color: #d1d5db;
  overflow-x: auto;
  max-height: 520px;
}

/* --------------------------------------------------------------------------
   Toast Notifications
   -------------------------------------------------------------------------- */
.hub-toast {
  position: fixed;
  bottom: 24px;
  right: 24px;
  background: rgba(14, 19, 28, 0.95);
  backdrop-filter: blur(16px);
  border: 1px solid var(--brand-cyan);
  color: #ffffff;
  padding: 12px 20px;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 12px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.6), 0 0 15px var(--brand-cyan-glow);
  z-index: 9999;
  display: flex;
  align-items: center;
  gap: 10px;
  transform: translateY(100px);
  opacity: 0;
  transition: all 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
  pointer-events: none;
}

.hub-toast.show {
  transform: translateY(0);
  opacity: 1;
  pointer-events: auto;
}

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */
.hub-footer {
  border-top: 1px solid var(--border-subtle);
  background: rgba(5, 7, 11, 0.9);
  padding: 32px 24px 40px;
  margin-top: auto;
}

.hub-footer-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.hub-footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 13px;
  font-family: var(--font-mono);
}

.hub-footer-links a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.15s ease;
}

.hub-footer-links a:hover {
  color: var(--brand-cyan);
}

.hub-footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  font-size: 12px;
  color: var(--text-dim);
  border-top: 1px solid var(--border-subtle);
  padding-top: 16px;
}

/* --------------------------------------------------------------------------
   Bilingual Switch Visibility Utility
   -------------------------------------------------------------------------- */
html[lang="zh-CN"] .lang-en,
html[lang="zh"] .lang-en {
  display: none !important;
}

html[lang="en"] .lang-zh {
  display: none !important;
}

html[lang="en"] .lang-en {
  display: inline !important;
}

html[lang="en"] div.lang-en,
html[lang="en"] p.lang-en,
html[lang="en"] section.lang-en,
html[lang="en"] ul.lang-en,
html[lang="en"] span.lang-en-block {
  display: block !important;
}