/* ========================================
   Y++ Studio Official Website
   Dark tech theme with accent gradients
   ======================================== */

:root {
  --bg-primary: #0a0b10;
  --bg-secondary: #10121a;
  --bg-card: #141722;
  --bg-card-hover: #1a1e2e;
  --bg-code: #0d0f17;

  --text-primary: #e8eaf0;
  --text-secondary: #8b90a0;
  --text-muted: #5a5f72;

  --accent: #6c5ce7;
  --accent-light: #a29bfe;
  --accent-glow: rgba(108, 92, 231, 0.3);
  --accent-gradient: linear-gradient(135deg, #6c5ce7, #00cec9);
  --accent-gradient-h: linear-gradient(90deg, #6c5ce7, #00cec9);

  --cyan: #00cec9;
  --cyan-glow: rgba(0, 206, 201, 0.2);

  --border: rgba(255, 255, 255, 0.06);
  --border-light: rgba(255, 255, 255, 0.1);

  --radius: 12px;
  --radius-lg: 20px;
  --radius-sm: 8px;

  --shadow-sm: 0 2px 8px rgba(0,0,0,0.2);
  --shadow-md: 0 8px 32px rgba(0,0,0,0.3);
  --shadow-lg: 0 16px 64px rgba(0,0,0,0.4);
  --shadow-glow: 0 0 40px var(--accent-glow);

  --nav-height: 72px;
  --container-width: 1200px;

  --font-sans: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Cascadia Code', 'Consolas', monospace;

  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ---- Reset & Base ---- */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
ul { list-style: none; }

::selection {
  background: var(--accent);
  color: #fff;
}

.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---- Navbar ---- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  z-index: 1000;
  background: rgba(10, 11, 16, 0.7);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  transition: var(--transition);
}

.navbar.scrolled {
  background: rgba(10, 11, 16, 0.92);
  box-shadow: 0 4px 20px rgba(0,0,0,0.3);
}

.nav-container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.2rem;
  transition: var(--transition);
}

.nav-logo:hover { opacity: 0.8; }

.logo-icon {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  font-weight: 900;
  font-size: 1.4rem;
  letter-spacing: -0.02em;
}

.logo-text {
  color: var(--text-primary);
  font-weight: 500;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-links a {
  padding: 8px 16px;
  font-size: 0.9rem;
  font-weight: 400;
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  transition: var(--transition);
  position: relative;
}

.nav-links a:hover {
  color: var(--text-primary);
  background: rgba(255,255,255,0.05);
}

.nav-links a.active {
  color: var(--accent-light);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: var(--transition);
}

/* ---- Hero ---- */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  position: relative;
  padding: calc(var(--nav-height) + 40px) 24px 60px;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(108, 92, 231, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(108, 92, 231, 0.05) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, black 20%, transparent 70%);
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, black 20%, transparent 70%);
}

.hero-glow {
  position: absolute;
  top: -20%;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, var(--accent-glow) 0%, rgba(0, 206, 201, 0.08) 40%, transparent 70%);
  filter: blur(60px);
  animation: glowPulse 8s ease-in-out infinite alternate;
}

@keyframes glowPulse {
  0% { opacity: 0.6; transform: translateX(-50%) scale(1); }
  100% { opacity: 1; transform: translateX(-50%) scale(1.15); }
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 900px;
}

.hero-badge {
  display: inline-block;
  padding: 6px 20px;
  border-radius: 50px;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--accent-light);
  background: rgba(108, 92, 231, 0.12);
  border: 1px solid rgba(108, 92, 231, 0.25);
  margin-bottom: 28px;
  letter-spacing: 0.04em;
}

.hero-title {
  font-size: clamp(3rem, 8vw, 5.5rem);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: 20px;
}

.hero-title-ypp {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* 首屏：Y++ 取名介绍（置于主标题下方、副标题之上） */
.hero-naming {
  max-width: 640px;
  margin: 0 auto 28px;
  padding: 20px 22px 20px 24px;
  text-align: left;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-light);
  border-radius: var(--radius);
  border-left: 3px solid var(--accent);
  box-shadow: var(--shadow-sm);
}

.hero-naming-label {
  display: block;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent-light);
  margin-bottom: 10px;
  opacity: 0.95;
}

.hero-naming-text {
  font-size: 0.95rem;
  line-height: 1.85;
  color: var(--text-secondary);
  margin: 0;
}

.hero-naming-text strong {
  font-weight: 600;
  color: var(--text-primary);
}

.hero-naming-y {
  color: var(--accent-light);
  font-family: var(--font-mono);
}

.hero-naming-pp {
  color: var(--cyan);
  font-family: var(--font-mono);
}

.hero-subtitle {
  font-size: clamp(1.1rem, 2.5vw, 1.5rem);
  color: var(--text-secondary);
  font-weight: 400;
  margin-bottom: 16px;
}

.hero-desc {
  font-size: 1rem;
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto 36px;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 56px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 28px;
  border-radius: var(--radius);
  font-size: 1rem;
  font-weight: 500;
  font-family: var(--font-sans);
  border: none;
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
}

.btn-primary {
  background: var(--accent-gradient);
  color: #fff;
  box-shadow: 0 4px 24px var(--accent-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(108, 92, 231, 0.45);
}

.btn-version {
  font-size: 0.75rem;
  opacity: 0.75;
  padding: 2px 8px;
  background: rgba(255,255,255,0.15);
  border-radius: 20px;
}

.btn-secondary {
  background: rgba(255,255,255,0.06);
  color: var(--text-primary);
  border: 1px solid var(--border-light);
}

.btn-secondary:hover {
  background: rgba(255,255,255,0.1);
  border-color: rgba(255,255,255,0.2);
  transform: translateY(-2px);
}

.btn-outline {
  background: transparent;
  color: var(--text-primary);
  border: 1px solid var(--border-light);
}

.btn-outline:hover {
  background: rgba(255,255,255,0.06);
  border-color: var(--accent);
  transform: translateY(-2px);
}

.btn-large {
  padding: 18px 36px;
  font-size: 1.05rem;
  border-radius: var(--radius);
}

/* Hero code preview */
.hero-code-preview {
  max-width: 600px;
  margin: 0 auto;
}

.code-window {
  background: var(--bg-code);
  border-radius: var(--radius);
  border: 1px solid var(--border-light);
  overflow: hidden;
  text-align: left;
  box-shadow: var(--shadow-lg);
}

.code-window.large {
  flex: 1;
  min-width: 0;
}

.code-titlebar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 14px 18px;
  background: rgba(255,255,255,0.03);
  border-bottom: 1px solid var(--border);
}

.code-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}
.code-dot.red { background: #ff5f57; }
.code-dot.yellow { background: #febc2e; }
.code-dot.green { background: #28c840; }

.code-filename {
  margin-left: 8px;
  font-size: 0.82rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.code-body {
  padding: 20px 24px;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  line-height: 1.75;
  overflow-x: auto;
  color: var(--text-secondary);
}

.code-body code { font-family: inherit; }
.code-body .kw { color: #c792ea; font-weight: 500; }
.code-body .fn { color: #82aaff; }
.code-body .var { color: #f0e68c; }
.code-body .str { color: #c3e88d; }
.code-body .num { color: #f78c6c; }
.code-body .cm { color: #546e7a; font-style: italic; }

.hero-scroll-hint {
  position: absolute;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  color: var(--text-muted);
  font-size: 0.8rem;
  animation: hintBounce 2.5s ease-in-out infinite;
}

@keyframes hintBounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(8px); }
}

/* ---- Sections ---- */
.section {
  padding: 120px 0;
  position: relative;
}

.section-header {
  text-align: center;
  margin-bottom: 64px;
}

.section-title {
  font-size: clamp(2rem, 4vw, 2.8rem);
  font-weight: 800;
  margin-bottom: 14px;
  letter-spacing: -0.02em;
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
}

/* ---- Features ---- */
.features {
  background: var(--bg-secondary);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 36px 32px;
  transition: var(--transition);
  opacity: 0;
  transform: translateY(30px);
}

.feature-card.visible {
  opacity: 1;
  transform: translateY(0);
}

.feature-card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(108, 92, 231, 0.25);
  transform: translateY(-4px);
  box-shadow: var(--shadow-glow);
}

.feature-icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(108, 92, 231, 0.1);
  border-radius: var(--radius);
  margin-bottom: 22px;
  color: var(--accent-light);
}

.feature-icon svg {
  width: 32px;
  height: 32px;
}

.feature-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.feature-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* ---- Code Examples ---- */
.code-tabs {
  display: flex;
  gap: 8px;
  justify-content: center;
  margin-bottom: 32px;
}

.code-tab {
  padding: 10px 24px;
  border-radius: 50px;
  font-size: 0.9rem;
  font-weight: 500;
  font-family: var(--font-sans);
  color: var(--text-secondary);
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border);
  cursor: pointer;
  transition: var(--transition);
}

.code-tab:hover {
  color: var(--text-primary);
  background: rgba(255,255,255,0.08);
}

.code-tab.active {
  color: #fff;
  background: var(--accent);
  border-color: var(--accent);
  box-shadow: 0 4px 16px var(--accent-glow);
}

.code-panels { position: relative; }

.code-panel {
  display: none;
  animation: fadeInPanel 0.4s ease;
}

.code-panel.active { display: block; }

@keyframes fadeInPanel {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

.code-panel-layout {
  display: flex;
  gap: 36px;
  align-items: flex-start;
}

.code-desc {
  flex: 0 0 280px;
  padding-top: 24px;
}

.code-desc h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.code-desc ul {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.code-desc li {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
  padding-left: 20px;
  position: relative;
}

.code-desc li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 9px;
  width: 6px;
  height: 6px;
  background: var(--accent);
  border-radius: 50%;
}

.code-desc code {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent-light);
  background: rgba(108, 92, 231, 0.12);
  padding: 2px 7px;
  border-radius: 4px;
}

/* ---- Standard Library ---- */
.stdlib {
  background: var(--bg-secondary);
}

.stdlib-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.stdlib-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  text-align: center;
  transition: var(--transition);
  opacity: 0;
  transform: translateY(20px);
}

.stdlib-card.visible {
  opacity: 1;
  transform: translateY(0);
}

.stdlib-card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(0, 206, 201, 0.3);
  transform: translateY(-3px);
  box-shadow: 0 0 30px var(--cyan-glow);
}

.stdlib-icon {
  width: 44px;
  height: 44px;
  margin: 0 auto 16px;
  color: var(--cyan);
}

.stdlib-icon svg {
  width: 100%;
  height: 100%;
}

.stdlib-card h4 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.stdlib-card p {
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ---- Pipeline / How it Works ---- */
.pipeline {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  gap: 0;
}

.pipeline-step {
  text-align: center;
  flex: 0 0 260px;
  padding: 32px 20px;
  opacity: 0;
  transform: translateY(20px);
}

.pipeline-step.visible {
  opacity: 1;
  transform: translateY(0);
}

.pipeline-number {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--accent-gradient);
  color: #fff;
  font-weight: 700;
  font-size: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 18px;
}

.pipeline-icon {
  width: 72px;
  height: 72px;
  margin: 0 auto 20px;
  color: var(--accent-light);
  background: rgba(108, 92, 231, 0.08);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
}

.pipeline-icon svg {
  width: 44px;
  height: 44px;
}

.pipeline-step h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.pipeline-step p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.pipeline-arrow {
  flex-shrink: 0;
  width: 60px;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  padding-top: 100px;
}

.pipeline-arrow svg {
  width: 40px;
  height: 24px;
}

/* ---- Download ---- */
.download {
  background: var(--bg-secondary);
}

.download-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 56px;
  display: flex;
  gap: 56px;
  align-items: center;
  position: relative;
  overflow: hidden;
  opacity: 0;
  transform: translateY(20px);
}

.download-card.visible {
  opacity: 1;
  transform: translateY(0);
}

.download-card::before {
  content: '';
  position: absolute;
  top: -1px;
  left: -1px;
  right: -1px;
  height: 3px;
  background: var(--accent-gradient-h);
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
}

.download-info {
  flex: 1;
}

.download-info h2 {
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 10px;
  letter-spacing: -0.02em;
}

.download-title {
  white-space: nowrap;
}

@media (max-width: 520px) {
  .download-title {
    white-space: normal;
  }
}

.download-info > p {
  color: var(--text-secondary);
  margin-bottom: 28px;
}

.download-meta {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
}

.meta-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.meta-label {
  font-size: 0.78rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.meta-value {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
}

.download-actions {
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  gap: 14px;
  align-items: center;
  max-width: 320px;
}

/* 下载区主按钮：避免过宽占满半屏 */
.download-actions .btn-large {
  padding: 12px 28px;
  font-size: 0.98rem;
  width: 100%;
  max-width: 280px;
  justify-content: center;
}

.download-actions .btn-large svg {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
}

.download-note {
  font-size: 0.78rem;
  color: var(--text-muted);
  text-align: center;
  margin-top: 4px;
}

.download-note a {
  color: var(--accent-light);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---- Docs ---- */
.docs-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.doc-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 28px;
  transition: var(--transition);
  opacity: 0;
  transform: translateY(20px);
}

.doc-card.visible {
  opacity: 1;
  transform: translateY(0);
}

.doc-card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(108, 92, 231, 0.25);
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.doc-icon {
  width: 48px;
  height: 48px;
  margin-bottom: 18px;
  color: var(--accent-light);
}

.doc-icon svg {
  width: 100%;
  height: 100%;
}

.doc-card h4 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.doc-card p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ---- Footer ---- */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  padding: 64px 0 0;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  gap: 48px;
  padding-bottom: 48px;
}

.footer-brand p {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-top: 12px;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.2rem;
}

.footer-links {
  display: flex;
  gap: 64px;
}

.footer-col {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-col h5 {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 6px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.footer-col a {
  font-size: 0.88rem;
  color: var(--text-muted);
  transition: var(--transition);
}

.footer-col a:hover {
  color: var(--accent-light);
}

.footer-bottom {
  border-top: 1px solid var(--border);
  padding: 24px 0;
  text-align: center;
}

.footer-bottom p {
  font-size: 0.82rem;
  color: var(--text-muted);
}

/* ---- Animate on scroll ---- */
[data-animate] {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

[data-animate].visible {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger animation delays for grids */
.features-grid [data-animate]:nth-child(1) { transition-delay: 0s; }
.features-grid [data-animate]:nth-child(2) { transition-delay: 0.08s; }
.features-grid [data-animate]:nth-child(3) { transition-delay: 0.16s; }
.features-grid [data-animate]:nth-child(4) { transition-delay: 0.24s; }
.features-grid [data-animate]:nth-child(5) { transition-delay: 0.32s; }
.features-grid [data-animate]:nth-child(6) { transition-delay: 0.4s; }

.stdlib-grid [data-animate]:nth-child(1)  { transition-delay: 0s; }
.stdlib-grid [data-animate]:nth-child(2)  { transition-delay: 0.05s; }
.stdlib-grid [data-animate]:nth-child(3)  { transition-delay: 0.1s; }
.stdlib-grid [data-animate]:nth-child(4)  { transition-delay: 0.15s; }
.stdlib-grid [data-animate]:nth-child(5)  { transition-delay: 0.2s; }
.stdlib-grid [data-animate]:nth-child(6)  { transition-delay: 0.25s; }
.stdlib-grid [data-animate]:nth-child(7)  { transition-delay: 0.3s; }
.stdlib-grid [data-animate]:nth-child(8)  { transition-delay: 0.35s; }
.stdlib-grid [data-animate]:nth-child(9)  { transition-delay: 0.4s; }
.stdlib-grid [data-animate]:nth-child(10) { transition-delay: 0.45s; }
.stdlib-grid [data-animate]:nth-child(11) { transition-delay: 0.5s; }
.stdlib-grid [data-animate]:nth-child(12) { transition-delay: 0.55s; }

.docs-grid [data-animate]:nth-child(1) { transition-delay: 0s; }
.docs-grid [data-animate]:nth-child(2) { transition-delay: 0.08s; }
.docs-grid [data-animate]:nth-child(3) { transition-delay: 0.16s; }
.docs-grid [data-animate]:nth-child(4) { transition-delay: 0.24s; }

/* ---- Responsive ---- */
@media (max-width: 1024px) {
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .stdlib-grid { grid-template-columns: repeat(3, 1fr); }
  .docs-grid { grid-template-columns: repeat(2, 1fr); }
  .download-card { flex-direction: column; padding: 40px 32px; gap: 36px; align-items: center; }
  .download-actions { align-items: center; align-self: center; width: 100%; max-width: 320px; }
  .code-panel-layout { flex-direction: column; }
  .code-desc { flex: none; }
}

@media (max-width: 768px) {
  .section { padding: 80px 0; }

  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    flex-direction: column;
    background: rgba(10, 11, 16, 0.97);
    backdrop-filter: blur(20px);
    padding: 16px 24px;
    border-bottom: 1px solid var(--border);
    gap: 4px;
  }

  .nav-links.open { display: flex; }
  .nav-toggle { display: flex; }

  .nav-toggle.open span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
  .nav-toggle.open span:nth-child(2) { opacity: 0; }
  .nav-toggle.open span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

  .features-grid { grid-template-columns: 1fr; }
  .stdlib-grid { grid-template-columns: repeat(2, 1fr); }
  .docs-grid { grid-template-columns: 1fr; }

  .pipeline {
    flex-direction: column;
    align-items: center;
  }
  .pipeline-arrow {
    transform: rotate(90deg);
    padding: 0;
    height: 40px;
  }
  .pipeline-step { flex: none; }

  .hero-title { font-size: 2.8rem; }

  .code-tabs { flex-wrap: wrap; }

  .download-meta { grid-template-columns: 1fr; }
  .download-card { padding: 32px 24px; }

  .footer-content { flex-direction: column; gap: 32px; }
  .footer-links { gap: 40px; flex-wrap: wrap; }
}

@media (max-width: 480px) {
  .hero { padding-top: calc(var(--nav-height) + 20px); }
  .hero-title { font-size: 2.2rem; }
  .hero-naming { padding: 16px 14px; margin-bottom: 22px; }
  .hero-naming-text { font-size: 0.88rem; }
  .hero-desc { font-size: 0.9rem; }
  .hero-actions { flex-direction: column; align-items: center; }
  .code-body { font-size: 0.78rem; padding: 14px 16px; }
  .stdlib-grid { grid-template-columns: 1fr; }
  .section-title { font-size: 1.8rem; }
  .footer-links { flex-direction: column; gap: 28px; }
}

/* ---- Stats Bar ---- */
.stats-bar {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 48px 0;
}

.stats-grid {
  display: flex;
  justify-content: center;
  gap: 64px;
  flex-wrap: wrap;
}

.stat-item {
  text-align: center;
  opacity: 0;
  transform: translateY(15px);
}

.stat-item.visible {
  opacity: 1;
  transform: translateY(0);
}

.stat-number {
  display: block;
  font-size: 2.8rem;
  font-weight: 900;
  letter-spacing: -0.03em;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.2;
}

.stat-label {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-top: 4px;
  display: block;
}

/* ---- Code Tabs Scroll ---- */
.code-tabs-scroll {
  overflow-x: auto;
  margin-bottom: 32px;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}

.code-tabs-scroll::-webkit-scrollbar { display: none; }

.code-tabs {
  display: flex;
  gap: 8px;
  justify-content: center;
  min-width: max-content;
  padding: 0 16px;
}

/* ---- GUI Showcase ---- */
.gui-showcase {
  background: var(--bg-secondary);
}

.gui-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: start;
}

.gui-components h3,
.gui-code-demo h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 20px;
}

.component-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.component-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 14px 18px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.component-item:hover {
  background: var(--bg-card-hover);
  border-color: rgba(108, 92, 231, 0.2);
}

.comp-icon {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(108, 92, 231, 0.1);
  color: var(--accent-light);
  border-radius: 6px;
  font-size: 1.1rem;
  font-weight: 700;
}

.component-item strong {
  font-size: 0.92rem;
  color: var(--text-primary);
}

.component-item span {
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.5;
}

/* ---- More Features ---- */
.more-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.more-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 20px;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease, background 0.3s ease, border-color 0.3s ease;
}

.more-item.visible {
  opacity: 1;
  transform: translateY(0);
}

.more-item:hover {
  background: var(--bg-card-hover);
  border-color: rgba(0, 206, 201, 0.2);
}

.more-item h4 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--cyan);
}

.more-item p {
  font-size: 0.82rem;
  line-height: 1.8;
  color: var(--text-secondary);
}

.more-item code {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--accent-light);
  background: rgba(108, 92, 231, 0.1);
  padding: 2px 6px;
  border-radius: 4px;
  white-space: nowrap;
}

.more-grid [data-animate]:nth-child(1) { transition-delay: 0s; }
.more-grid [data-animate]:nth-child(2) { transition-delay: 0.06s; }
.more-grid [data-animate]:nth-child(3) { transition-delay: 0.12s; }
.more-grid [data-animate]:nth-child(4) { transition-delay: 0.18s; }
.more-grid [data-animate]:nth-child(5) { transition-delay: 0.24s; }
.more-grid [data-animate]:nth-child(6) { transition-delay: 0.3s; }
.more-grid [data-animate]:nth-child(7) { transition-delay: 0.36s; }
.more-grid [data-animate]:nth-child(8) { transition-delay: 0.42s; }

/* ---- Responsive additions ---- */
@media (max-width: 1024px) {
  .gui-layout { grid-template-columns: 1fr; }
  .more-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-grid { gap: 40px; }
}

@media (max-width: 768px) {
  .more-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-grid { gap: 24px; }
  .stat-number { font-size: 2.2rem; }
  .code-tabs { justify-content: flex-start; }
}

@media (max-width: 480px) {
  .more-grid { grid-template-columns: 1fr; }
  .stats-grid { gap: 20px; }
  .stat-number { font-size: 1.8rem; }
}

/* ---- Scrollbar ---- */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: var(--bg-primary); }
::-webkit-scrollbar-thumb { background: #2a2d3e; border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: #3a3d4e; }