/* ============================================
   Tech-Renaissance / 技术觉醒
   Snap-scroll, mobile-first, pure CSS
   ============================================ */

:root {
  --bg-primary: #0A0A0F;
  --bg-card: #12121A;
  --bg-code: #0E0E1A;
  --bg-footer: #080810;
  --nav-bg: rgba(10, 10, 15, 0.92);
  --text-primary: #FFFFFF;
  --text-secondary: #A1A1B5;
  --color-purple: #A855F7;
  --color-purple-dark: #9333EA;
  --color-purple-light: #C084FC;
  --color-blue: #3B82F6;
  --border-color: #1E1E2E;
  --color-green: #22C55E;
  --color-gray: #3D3D5C;
  --color-dark-gray: #2A2A40;
  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
  --font-code: Arial, "Helvetica Neue", Helvetica, "Segoe UI", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Courier New", monospace;
  --radius-sm: 6px;
  --radius-md: 8px;
  --nav-height: 56px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; overflow-x: hidden; }

body {
  font-family: var(--font-body);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button { border: none; background: none; cursor: pointer; font-family: inherit; color: inherit; }
pre { font-family: var(--font-code); overflow-x: auto; -webkit-overflow-scrolling: touch; }

.desktop-only { display: none; }
.mobile-only { display: flex; }
.text-center { text-align: center; }

.mobile-br { display: block; }

/* ===== SCROLL SNAP ===== */
.snap-container {
  scroll-snap-type: y mandatory;
  overflow-y: scroll;
  height: 100dvh;
  height: 100vh;
  -webkit-overflow-scrolling: touch;
}

.snap-section {
  scroll-snap-align: start;
  scroll-snap-stop: always;
  min-height: 100dvh;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: calc(var(--nav-height) + 16px) 0 24px;
  position: relative;
}

.footer-section {
  min-height: auto;
  scroll-snap-align: end;
}

/* ===== NAVBAR ===== */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  background: var(--nav-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--nav-height);
  padding: 0 16px;
  max-width: 1200px;
  margin: 0 auto;
}

.nav-logo { display: flex; align-items: center; gap: 10px; }
.logo-img { width: 34px; height: 28px; }
.logo-text { font-size: 23px; font-weight: 600; color: var(--color-purple); letter-spacing: 0.3px; }

.nav-mobile-right { align-items: center; gap: 4px; }
.nav-icon-btn {
  display: flex; align-items: center; justify-content: center;
  width: 44px; height: 44px;
  color: var(--text-secondary);
  transition: color 0.25s ease;
}
.nav-icon-btn:active { color: var(--text-primary); }

.mobile-menu {
  max-height: 0; overflow: hidden; opacity: 0;
  transition: max-height 0.35s ease, opacity 0.25s ease;
  background: var(--nav-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
}
.mobile-menu.open { max-height: 320px; opacity: 1; border-bottom-color: var(--border-color); }
.mobile-nav-link {
  display: block; padding: 14px 20px; font-size: 15px;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border-color);
  min-height: 48px;
}
.mobile-nav-link:last-child { border-bottom: none; }
.mobile-nav-link:active { color: var(--text-primary); background: rgba(168, 85, 247, 0.08); }

/* ===== HERO ===== */
.hero-container {
  width: 100%;
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 36px;
}

.hero-content { text-align: center; width: 100%; }
.hero-image-wrap { width: 100%; max-width: 560px; overflow: hidden; }

.hero-title { font-size: 36px; font-weight: 700; line-height: 1.1; letter-spacing: -0.5px; }

.hero-title-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  margin: 8px 0 18px;
  flex-wrap: wrap;
}

@media (min-width: 768px) {
  .hero-title-row {
    justify-content: flex-start;
    gap: 24px;
  }
}

.hero-title-sub { font-size: 32px; font-weight: 700; color: var(--text-primary); }

/* V4.20 Release Badge */
.release-badge {
  display: inline-block;
  background: var(--color-purple);
  padding: 4px 10px;
  transform: skewX(-12deg);
  box-shadow: 0 2px 10px rgba(168, 85, 247, 0.3);
  flex-shrink: 0;
}

.badge-text {
  display: block;
  font-size: 12px;
  font-weight: 600;
  color: #fff;
  white-space: nowrap;
  transform: skewX(12deg);
}
.hero-subtitle { font-size: 16px; color: var(--text-secondary); margin-bottom: 12px; line-height: 1.5; }
.hero-highlight { font-size: 13px; color: var(--color-purple); font-weight: 500; margin-bottom: 28px; line-height: 1.5; }

.hero-image {
  width: 100%;
  border-radius: var(--radius-md);
  transform: scale(1.2);
}

/* ===== BUTTONS ===== */
.hero-buttons {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  gap: 15px;
  max-width: 224px;
  margin: 0 auto;
  margin-top: 10px;
}

.btn {
  display: inline-flex; align-items: center; justify-content: center;
  gap: 8px;
  min-height: 44px; padding: 10px 20px;
  font-size: 14px; font-weight: 500;
  border-radius: var(--radius-sm);
  transition: all 0.25s ease;
  cursor: pointer; white-space: nowrap;
}
.btn-icon { width: 16px; height: 16px; flex-shrink: 0; }

.btn-primary { background: var(--color-purple); color: #fff; border: 1px solid var(--color-purple); }
.btn-primary:active { background: var(--color-purple-dark); border-color: var(--color-purple-dark); }
.btn-secondary { background: transparent; color: var(--color-purple); border: 1px solid var(--color-purple); }
.btn-secondary:active { background: rgba(168, 85, 247, 0.12); }

/* ===== SECTIONS ===== */
.section-container { width: 100%; max-width: 1140px; margin: 0 auto; padding: 0 20px; }
.section-title { font-size: 24px; font-weight: 600; margin-bottom: 8px; }
.section-subtitle { font-size: 14px; color: var(--text-secondary); margin-bottom: 28px; }

/* ===== BENCHMARK ===== */
.bar-chart { margin-bottom: 24px; }
.bar-row { display: flex; flex-direction: column; margin-bottom: 16px; gap: 6px; }
.baseline-row { opacity: 0.55; }
.bar-label { font-size: 15px; font-weight: 500; }
.bar-track { width: 100%; height: 28px; background: var(--bg-code); border-radius: var(--radius-sm); overflow: hidden; }
.bar-fill { height: 100%; border-radius: var(--radius-sm); width: var(--bar-width); }
.bar-gradient { background: linear-gradient(90deg, var(--color-blue) 0%, var(--color-purple) 100%); box-shadow: 0 0 16px rgba(168, 85, 247, 0.3); }
.bar-gray { background: var(--color-gray); }
.bar-baseline { background: var(--color-dark-gray); }
.bar-value { font-size: 14px; color: var(--text-secondary); }
.bar-faster { color: var(--color-purple); font-weight: 500; }
.bar-baseline-text { color: var(--text-secondary); font-style: italic; }

.epoch-table { background: var(--bg-code); border: 1px solid var(--border-color); border-radius: var(--radius-md); overflow: hidden; margin-bottom: 20px; }
.table-header, .table-row { display: grid; grid-template-columns: 1.4fr 0.8fr 1fr; padding: 11px 14px; font-size: 12px; border-bottom: 1px solid var(--border-color); }
.table-header { color: var(--text-secondary); font-weight: 500; background: rgba(168, 85, 247, 0.04); }
.table-row:last-child { border-bottom: none; }
.table-highlight { color: var(--color-purple); font-weight: 500; }
.benchmark-note { font-size: 11px; color: var(--text-secondary); text-align: center; margin-bottom: 20px; opacity: 0.7; }

/* ===== CODE SHOWCASE (body font, 1:2 split) ===== */
.code-showcase { background: var(--bg-code); }

.code-split { display: flex; flex-direction: column; gap: 16px; }

.code-panel {
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.code-panel-header {
  text-align: center;
  padding: 10px 16px;
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
  border-bottom: 1px solid var(--border-color);
  background: rgba(168, 85, 247, 0.05);
}

.code-body { padding: 12px; }
.code-scroll { overflow-x: auto; }

.code-tight {
  font-family: var(--font-body);
  font-size: 12px;
  line-height: 1.6;
  color: #D4D4D8;
  white-space: pre;
  margin: 0;
  padding: 0;
}

.code-tight .ln {
  display: inline-block;
  width: 24px;
  text-align: right;
  color: #4B4B60;
  font-size: 10px;
  margin-right: 6px;
  user-select: none;
}

/* Syntax */
.code-kw { color: #C084FC; }
.code-str { color: #86EFAC; }
.code-num { color: #93C5FD; }
.code-func { color: #D4D4D8; }
.code-type { color: #FCD34D; }

/* ===== QUICK START (zigzag) ===== */
.quickstart-zigzag { display: flex; flex-direction: column; gap: 16px; }

.zigzag-row {
  display: flex;
  flex-direction: column;
  background: var(--bg-code);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.zigzag-label {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 20px;
  background: rgba(168, 85, 247, 0.06);
  border-bottom: 1px solid var(--border-color);
}

.zigzag-code { padding: 12px 16px; }
.zigzag-code .code-content { padding: 0; }

.step-num {
  display: flex; align-items: center; justify-content: center;
  width: 32px; height: 32px; border-radius: 50%;
  background: var(--color-purple); color: #fff;
  font-size: 16px; font-weight: 700; flex-shrink: 0;
}
.step-name { font-size: 16px; font-weight: 600; }

.expected-output {
  margin-top: 12px; padding: 12px 14px;
  background: rgba(168, 85, 247, 0.04);
  border: 1px solid var(--border-color); border-radius: var(--radius-sm);
}
.expected-output pre { font-family: var(--font-code); font-size: 12px; color: var(--text-secondary); white-space: pre-wrap; word-break: break-all; }

.quickstart-note { font-size: 13px; color: var(--text-secondary); text-align: center; margin-top: 24px; }

@media (max-width: 767px) {
  .zigzag-right .zigzag-label { order: -1; }
}

.code-content.bash {
  font-family: var(--font-body);
  font-size: 13px;
  line-height: 1.7;
  color: #D4D4D8;
  white-space: pre-wrap;
  word-break: break-all;
}

.code-plain {
  font-family: var(--font-body);
  font-size: 14px;
  line-height: 1.7;
  color: #D4D4D8;
  white-space: pre-wrap;
  word-break: break-all;
  margin: 0;
  padding: 0;
}

/* ===== WHAT'S NEW (larger + images) ===== */
.whats-new { background: var(--bg-card); }

.cards-grid {
  display: flex; gap: 16px;
  overflow-x: auto;
  padding-bottom: 8px;
  margin: 0 -20px; padding-left: 20px; padding-right: 20px;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}
.cards-grid::-webkit-scrollbar { display: none; }

.news-card {
  flex: 0 0 310px;
  background: var(--bg-code); border: 1px solid var(--border-color);
  border-radius: var(--radius-md); overflow: hidden;
}
.highlight-card { border-color: rgba(168, 85, 247, 0.4); box-shadow: 0 0 20px rgba(168, 85, 247, 0.06); }

.news-image { width: 100%; height: 160px; object-fit: cover; border-bottom: 1px solid var(--border-color); }

.news-body { padding: 18px; }
.news-tag { display: inline-block; font-size: 12px; font-weight: 500; padding: 4px 12px; border-radius: 20px; margin-bottom: 12px; }
.tag-milestone { background: rgba(168, 85, 247, 0.15); color: var(--color-purple); }
.tag-release { background: rgba(168, 85, 247, 0.2); color: var(--color-purple-light); border: 1px solid rgba(168, 85, 247, 0.3); }

.news-title { font-size: 18px; font-weight: 600; margin-bottom: 10px; line-height: 1.4; }
.news-content { font-size: 14px; color: var(--text-secondary); line-height: 1.65; margin-bottom: 14px; }
.news-date { font-size: 13px; color: var(--text-secondary); opacity: 0.7; }

/* ===== TECH FEATURES (staggered) ===== */
.tech-features { background: var(--bg-primary); padding-top: 40px; }
.tech-features .section-title { margin-top: -60px; }

.features-staggered {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.feature-card {
  background: var(--bg-card); border: 1px solid var(--border-color);
  border-radius: var(--radius-md); padding: 28px 20px;
  text-align: center;
}

.feature-icon { width: 56px; height: 56px; margin: 0 auto 16px; }
.feature-icon svg { width: 100%; height: 100%; }

.feature-title { font-size: 17px; font-weight: 600; margin-bottom: 10px; }
.feature-desc { font-size: 14px; color: var(--text-secondary); line-height: 1.6; }

/* ===== AUTHOR ===== */
.author { background: var(--bg-card); }

.author-grid {
  display: flex; flex-direction: column;
  gap: 36px;
  width: 100%;
}

.author-prefix { font-size: 16px; font-weight: 700; color: var(--color-purple); margin-bottom: 6px; }
.author-name { font-size: 28px; font-weight: 700; margin-bottom: 16px; }
.author-name .degree { font-size: 20px; }

.author-tags {
  display: flex; flex-wrap: wrap;
  gap: 8px; margin-bottom: 18px;
}

.author-tag {
  display: inline-block; font-size: 12px;
  padding: 5px 12px; border-radius: 20px;
  background: rgba(168, 85, 247, 0.1);
  color: var(--color-purple);
  border: 1px solid transparent;
}
.author-tag.tag-outline { background: transparent; border-color: var(--color-purple); }

.author-bio { font-size: 14px; color: var(--text-secondary); line-height: 1.8; max-width: 520px; }

.contact-title { font-size: 16px; font-weight: 600; margin-bottom: 18px; }
.contact-list { list-style: none; }
.contact-item {
  display: flex; align-items: center; gap: 12px;
  padding: 11px 0; font-size: 14px;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border-color);
}
.contact-item:last-child { border-bottom: none; }
.contact-item a { color: var(--color-purple); word-break: break-all; }
.contact-icon { width: 18px; height: 18px; flex-shrink: 0; }

/* ===== FOOTER ===== */
.footer { background: var(--bg-footer); width: 100%; }
.footer-container { max-width: 1140px; margin: 0 auto; padding: 28px 20px 20px; }
.footer-main {
  display: flex; flex-direction: column; gap: 8px;
  margin-bottom: 16px; padding-bottom: 14px;
  border-bottom: 1px solid var(--border-color);
}
.footer-left { font-size: 14px; font-weight: 500; }
.footer-right { font-size: 12px; color: var(--text-secondary); }
.footer-bottom { font-size: 11px; color: var(--text-secondary); opacity: 0.6; }

/* ============================================
   DESKTOP >= 768px
   ============================================ */
@media (min-width: 768px) {
  .mobile-br { display: none; }
  .desktop-only { display: flex; }
  .mobile-only { display: none; }

  :root { --nav-height: 60px; }
  .nav-container { padding: 0 24px; }
  .nav-links { align-items: center; gap: 4px; }
  .nav-link {
    font-size: 14px; color: var(--text-secondary);
    padding: 8px 14px; border-radius: var(--radius-sm);
    transition: color 0.25s ease, background 0.25s ease;
    min-height: 36px; display: inline-flex; align-items: center;
  }
  .nav-link:hover { color: var(--text-primary); background: rgba(168, 85, 247, 0.06); }
  .nav-link-active { color: var(--color-purple) !important; }

  /* Hero: PC.png as full background on desktop */
  .hero {
    background-image: url('assets/PC.png');
    background-size: cover;
    background-position: center right;
    background-repeat: no-repeat;
  }
  .hero-container {
    max-width: 1140px;
    padding: 0 24px;
    flex-direction: row;
    align-items: center;
    gap: 48px;
  }
  .hero-content {
    flex: 0 0 50%;
    text-align: left;
  }
  .hero-image-wrap {
    display: none;
  }
  .hero-title { font-size: 52px; }
  .hero-title-sub { font-size: 52px; }
  .release-badge { padding: 5px 12px; }
  .badge-text { font-size: 14px; }
  .hero-subtitle { font-size: 18px; }
  .hero-highlight { font-size: 15px; }

  .hero-buttons {
    flex-direction: row;
    justify-content: flex-start;
    max-width: none;
    margin: 0;
    gap: 12px;
  }

  /* Section titles */
  .section-title { font-size: 28px; margin-bottom: 10px; }
  .section-subtitle { font-size: 15px; margin-bottom: 32px; }

  /* Benchmark */
  .bar-chart { max-width: 800px; margin: 0 auto 28px; }
  .bar-row { flex-direction: row; align-items: center; gap: 14px; }
  .bar-label { flex: 0 0 200px; text-align: right; font-size: 14px; }
  .bar-track { flex: 1; height: 32px; }
  .bar-value { flex: 0 0 310px; font-size: 13px; }
  .epoch-table { max-width: 800px; margin: 0 auto 24px; }
  .table-header, .table-row { padding: 12px 18px; font-size: 13px; }

  /* Code: side by side 1:2 */
	  .code-split { flex-direction: row; gap: 20px; }
	  .code-panel-left { flex: 1.38; }
	  .code-panel-right { flex: 1.445; }
	  .code-panel-header { font-size: 18px; padding: 12px 16px; }
	  .code-body { padding: 14px; }
	  .code-tight { font-size: 13px; }

  /* Quick Start: zigzag */
	  .quickstart-zigzag { gap: 20px; max-width: 980px; margin: 0 auto; }

  .zigzag-row {
    flex-direction: row;
    align-items: center;
  }
  .zigzag-row.zigzag-right { flex-direction: row-reverse; }

  .zigzag-label {
    flex: 0 0 180px;
    border-bottom: none;
    border-right: 1px solid var(--border-color);
    justify-content: center;
  }
  .zigzag-row.zigzag-right .zigzag-label {
    border-right: none;
    border-left: 1px solid var(--border-color);
  }

  .zigzag-code { flex: 1; padding: 16px 20px; }

  /* What's New */
  .cards-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
    overflow-x: visible;
    margin: 0 auto;
    padding: 0;
    max-width: 900px;
  }
  .news-card { flex: none; }
  .news-image { height: 180px; }
  .news-title { font-size: 20px; }
  .news-content { font-size: 15px; }

  /* Tech Features: staggered */
  .features-staggered {
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    max-width: 1000px;
    margin: 0 auto;
  }
  .feature-card { padding: 36px 24px; }
  .stagger-up { transform: translateY(0); }
  .stagger-down { transform: translateY(0); }
  .feature-icon { width: 64px; height: 64px; }
  .feature-title { font-size: 18px; }
  .feature-desc { font-size: 15px; }

  /* Author */
  .author-grid { flex-direction: row; gap: 60px; }
  .author-left { flex: 0 0 58%; }
  .author-right { flex: 1; }
  .author-prefix { font-size: 18px; }
  .author-name { font-size: 32px; }
  .author-name .degree { font-size: 22px; }

  /* Footer */
  .footer-main { flex-direction: row; justify-content: space-between; align-items: center; }
}

@media (min-width: 768px) {
  .btn:hover { transform: translateY(-1px); }
  .btn-primary:hover { background: var(--color-purple-light); border-color: var(--color-purple-light); }
  .btn-secondary:hover { background: rgba(168, 85, 247, 0.08); border-color: var(--color-purple-light); color: var(--color-purple-light); }
}