/* QuickLook — Windows 11 / Fluent 2 开放版设计系统
   关键词：开放、留白、大字号、真实截图、沉浸段落 */

:root {
  /* 颜色 —— 克制，主蓝来自 QuickLook Logo */
  --ink: #1b1b1f;
  --ink-soft: #616161;
  --paper: #fbfbfd;
  --paper-2: #f3f4f6;
  --surface: #ffffff;
  --line: rgba(27, 27, 31, 0.08);
  --line-strong: rgba(27, 27, 31, 0.18);
  --blue: #0f6cbd;
  --blue-light: #4ea6f2;
  --blue-deep: #0a4f8a;
  --blue-tint: #e6f3fd;
  --dark: #0c0c10;
  --dark-elev: #15151d;

  /* 字体 */
  --font: "Segoe UI Variable", "Segoe UI", system-ui, -apple-system, BlinkMacSystemFont, sans-serif;

  /* 间距标尺 */
  --space-xs: 8px;
  --space-sm: 16px;
  --space-md: 24px;
  --space-lg: 40px;
  --space-xl: 64px;
  --space-2xl: 96px;
  --space-3xl: 144px;

  /* 容器 */
  --max: 1280px;
  --gutter: 24px;

  /* 圆角 */
  --radius: 12px;
  --radius-lg: 18px;
  --radius-sm: 8px;
}

/* Reset */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-font-smoothing: antialiased; }
body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background: var(--paper);
  line-height: 1.6;
}
h1, h2, h3, h4, p { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button { font: inherit; }

/* 容器 */
.container {
  width: 100%;
  max-width: var(--max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.section {
  padding-block: var(--space-2xl);
}
.section-tight { padding-block: var(--space-xl); }
.section-hero { padding-block: 0; }

/* 全宽出血带 */
.full-bleed {
  width: 100vw;
  position: relative;
  left: 50%;
  right: 50%;
  margin-left: -50vw;
  margin-right: -50vw;
}

/* 排版系统 */
.display-hero {
  font-size: clamp(48px, 7vw, 96px);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -0.04em;
}
.display-section {
  font-size: clamp(40px, 5vw, 72px);
  font-weight: 700;
  line-height: 1.08;
  letter-spacing: -0.035em;
}
.headline {
  font-size: clamp(28px, 3vw, 42px);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
}
.title-lg {
  font-size: 24px;
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.01em;
}
.title-md {
  font-size: 18px;
  font-weight: 600;
  line-height: 1.35;
}
.body-lg {
  font-size: clamp(18px, 1.4vw, 22px);
  line-height: 1.55;
  color: var(--ink-soft);
}
.body-md {
  font-size: 16px;
  line-height: 1.6;
  color: var(--ink-soft);
}
.body-sm {
  font-size: 14px;
  line-height: 1.55;
  color: var(--ink-soft);
}
.label {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* 眉标 */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--blue);
  margin-bottom: var(--space-sm);
}
.eyebrow::before {
  content: "";
  width: 24px;
  height: 2px;
  background: var(--blue);
}
.eyebrow-light::before { background: var(--blue-light); }

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 600;
  transition: transform .15s ease, box-shadow .2s ease, background .2s ease;
  cursor: pointer;
  border: 0;
}
.btn:hover { transform: translateY(-1px); }
.btn-primary {
  background: var(--blue);
  color: #fff;
  box-shadow: 0 6px 24px rgba(15, 108, 189, .28);
}
.btn-primary:hover { background: var(--blue-deep); box-shadow: 0 8px 28px rgba(15, 108, 189, .35); }
.btn-secondary {
  background: var(--surface);
  color: var(--ink);
  border: 1px solid var(--line-strong);
}
.btn-secondary:hover { border-color: var(--blue); color: var(--blue); }
.btn-ghost {
  background: rgba(255, 255, 255, .1);
  color: #fff;
  border: 1px solid rgba(255, 255, 255, .25);
  backdrop-filter: blur(6px);
}
.btn-ghost:hover { background: rgba(255, 255, 255, .18); }

/* 导航 */
.nav {
  position: absolute;
  inset: 0 0 auto 0;
  z-index: 100;
  padding-block: 18px;
  transition: background .2s ease, box-shadow .2s ease;
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 18px;
  color: #fff;
}
.logo img { height: 28px; width: auto; }
.nav-links {
  display: flex;
  gap: 32px;
}
.nav-links a {
  font-size: 14px;
  font-weight: 600;
  color: rgba(255, 255, 255, .82);
  transition: color .2s;
}
.nav-links a:hover,
.nav-links a.active { color: #fff; }
.nav.scrolled {
  position: fixed;
  background: rgba(255, 255, 255, .92);
  backdrop-filter: blur(16px);
  box-shadow: 0 1px 0 var(--line);
  padding-block: 14px;
}
.nav.scrolled .nav-links a { color: var(--ink-soft); }
.nav.scrolled .nav-links a:hover,
.nav.scrolled .nav-links a.active { color: var(--blue); }
.nav.scrolled .logo { color: var(--ink); }

/* Hero —— 全屏沉浸 */
.hero {
  min-height: 100vh;
  display: grid;
  align-items: end;
  position: relative;
  overflow: hidden;
  color: #fff;
}
.hero-bg {
  position: absolute;
  inset: 0;
  z-index: -2;
}
.hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}
.hero-overlay {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, rgba(8,22,44,.95) 0%, rgba(8,22,44,.82) 38%, rgba(8,22,44,.45) 66%, rgba(8,22,44,.12) 100%),
    linear-gradient(0deg, rgba(8,22,44,.78) 0%, rgba(8,22,44,.3) 32%, transparent 60%);
  z-index: -1;
}
.hero-content {
  padding-block: 180px var(--space-3xl);
}
.hero .body-lg {
  color: rgba(255, 255, 255, .82);
  margin-top: var(--space-md);
  max-width: 580px;
}
.hero-actions {
  margin-top: var(--space-lg);
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}
.hero-meta {
  margin-top: var(--space-sm);
  font-size: 13px;
  color: rgba(255, 255, 255, .55);
}

/* 英雄版 Secondary */
.hero-compact {
  min-height: 70vh;
  display: grid;
  align-items: end;
  position: relative;
  overflow: hidden;
  color: #fff;
  background: var(--dark);
}
.hero-compact .hero-content {
  padding-block: 140px var(--space-2xl);
}
.hero-compact .body-lg { color: rgba(255,255,255,.75); }

/* 滚动提示 */
.scroll-hint {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: rgba(255,255,255,.55);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.scroll-hint::after {
  content: "";
  width: 1px;
  height: 40px;
  background: rgba(255,255,255,.35);
  animation: scrollPulse 2s infinite;
}
@keyframes scrollPulse {
  0%, 100% { opacity: .3; transform: scaleY(1); transform-origin: top; }
  50% { opacity: 1; transform: scaleY(1.3); transform-origin: top; }
}

/* 宣言条 */
.manifesto {
  padding-block: var(--space-3xl);
  text-align: center;
}
.manifesto h2 {
  font-size: clamp(36px, 5vw, 72px);
  font-weight: 700;
  line-height: 1.12;
  letter-spacing: -0.04em;
}
.manifesto .body-lg {
  max-width: 680px;
  margin: var(--space-md) auto 0;
}

/* 大数字统计 */
.stats-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.stat-item {
  padding-block: var(--space-xl);
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
  position: relative;
}
.stat-item + .stat-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: var(--space-lg);
  bottom: var(--space-lg);
  width: 1px;
  background: var(--line);
}
.stat-number {
  font-size: clamp(56px, 7vw, 110px);
  font-weight: 700;
  line-height: .95;
  letter-spacing: -0.05em;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}
.stat-label {
  font-size: 15px;
  font-weight: 600;
  color: var(--ink-soft);
}

/* 编辑式步骤 */
.steps-editorial {
  display: grid;
  gap: var(--space-2xl);
}
.step-editorial {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: var(--space-xl);
  align-items: start;
}
.step-number {
  font-size: clamp(96px, 12vw, 180px);
  font-weight: 700;
  line-height: .8;
  letter-spacing: -0.06em;
  color: var(--blue-tint);
  user-select: none;
}
.step-body { max-width: 560px; }
.step-body h3 { margin-bottom: var(--space-xs); }
.step-body p { color: var(--ink-soft); }

/* 截图画廊 */
.gallery-track {
  display: flex;
  gap: var(--space-md);
  padding: var(--space-xl) var(--gutter);
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
}
.gallery-track::-webkit-scrollbar { height: 6px; }
.gallery-track::-webkit-scrollbar-thumb { background: rgba(255,255,255,.25); border-radius: 4px; }
.gallery-item {
  flex: 0 0 auto;
  scroll-snap-align: start;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 24px 60px rgba(0,0,0,.35);
}
.gallery-item img { height: 420px; width: auto; max-width: none; object-fit: cover; }
.gallery-item.wide img { height: 420px; width: auto; }

/* 图片-文字交替 */
.split-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-2xl);
  align-items: center;
}
.split-row + .split-row { margin-top: var(--space-3xl); }
.split-row.reverse { direction: rtl; }
.split-row.reverse > * { direction: ltr; }
.split-media {
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 24px 70px rgba(0,0,0,.12);
}
.split-media img { width: 100%; height: auto; }
.split-text { max-width: 540px; }
.split-text .eyebrow { margin-bottom: var(--space-md); }
.split-text h2 { margin-bottom: var(--space-sm); }
.split-text p { margin-bottom: var(--space-md); }

/* Bento —— 开放版 */
.bento {
  display: grid;
  gap: var(--space-md);
}
.bento-2 { grid-template-columns: 1fr 1fr; }
.bento-3 { grid-template-columns: repeat(3, 1fr); }
.bento-item {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  position: relative;
  overflow: hidden;
}
.bento-item.wide { grid-column: span 2; }
.bento-item.tall { grid-row: span 2; }
.bento-item.feature-dark {
  background: var(--dark);
  color: #fff;
  border-color: rgba(255,255,255,.08);
}
.bento-item.feature-dark p { color: rgba(255,255,255,.72); }
.bento-media { margin: calc(var(--space-xl) * -1); margin-top: var(--space-md); }
.bento-media img { width: 100%; height: auto; }

/* 格式页 */
.formats-filter {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-bottom: var(--space-xl);
}
.filter-btn {
  padding: 10px 18px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--surface);
  font-size: 14px;
  font-weight: 600;
  color: var(--ink-soft);
  cursor: pointer;
  transition: .15s;
}
.filter-btn:hover { border-color: var(--blue); color: var(--blue); }
.filter-btn.active { background: var(--blue); color: #fff; border-color: var(--blue); }
.formats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 14px;
}
.format-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px;
  transition: transform .15s, box-shadow .2s, border-color .2s;
}
.format-card:hover {
  transform: translateY(-2px);
  border-color: var(--blue-light);
  box-shadow: 0 8px 24px rgba(15, 108, 189, .10);
}
.format-card .title-md { margin-bottom: 4px; }
.format-card .body-sm { font-size: 13px; }

/* 下载页 */
.download-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-md);
}
.download-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  transition: transform .15s, box-shadow .2s;
}
.download-card:hover { transform: translateY(-2px); box-shadow: 0 16px 40px rgba(0,0,0,.08); }
.download-card.feature-dark {
  background: var(--dark);
  color: #fff;
  border-color: rgba(255,255,255,.1);
}
.download-card.feature-dark p { color: rgba(255,255,255,.72); }
.download-card .title-lg { margin-bottom: 4px; }
.download-card p { flex: 1; }

.sys-requirements {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-md);
  margin-top: var(--space-xl);
}
.sys-item {
  padding: var(--space-md);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

/* 关于页 */
.about-lead {
  font-size: clamp(22px, 2.4vw, 32px);
  line-height: 1.5;
  color: var(--ink-soft);
  max-width: 880px;
}
.about-lead strong { color: var(--ink); }

/* CTA 沉浸带 */
.cta-immersive {
  background: var(--dark);
  color: #fff;
  padding-block: var(--space-3xl);
  position: relative;
  overflow: hidden;
}
.cta-immersive::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 30% 50%, rgba(15,108,189,.22) 0%, transparent 55%);
}
.cta-immersive .container { position: relative; z-index: 1; }
.cta-immersive h2 {
  font-size: clamp(40px, 5vw, 72px);
  font-weight: 700;
  line-height: 1.08;
  letter-spacing: -0.03em;
  max-width: 720px;
}
.cta-immersive p { color: rgba(255,255,255,.72); margin: var(--space-sm) 0 var(--space-lg); max-width: 540px; }

/* Footer */
.footer {
  background: var(--paper-2);
  border-top: 1px solid var(--line);
  padding-block: var(--space-xl);
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: var(--space-xl);
}
.footer p { color: var(--ink-soft); font-size: 14px; margin-top: 10px; }
.footer h4 { font-size: 13px; font-weight: 700; letter-spacing: 0.06em; text-transform: uppercase; margin-bottom: var(--space-sm); }
.footer a { display: block; font-size: 14px; color: var(--ink-soft); padding: 4px 0; transition: color .2s; }
.footer a:hover { color: var(--blue); }
.footer-bottom {
  margin-top: var(--space-xl);
  padding-top: var(--space-md);
  border-top: 1px solid var(--line);
  font-size: 13px;
  color: var(--ink-soft);
  display: flex;
  justify-content: space-between;
}

/* 版本徽标 + 更新日志（JSON 驱动） */
.hero-meta { margin-bottom: var(--space-md); }
.version-badge {
  display: inline-block;
  padding: 7px 14px;
  border-radius: 999px;
  background: rgba(255,255,255,.12);
  border: 1px solid rgba(255,255,255,.22);
  color: #fff;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .01em;
  backdrop-filter: blur(6px);
}
.changelog { display: flex; flex-direction: column; gap: var(--space-md); max-width: 820px; }
.changelog-item {
  border: 1px solid var(--line);
  border-left: 3px solid var(--blue);
  border-radius: 8px;
  background: var(--surface);
  padding: var(--space-md) var(--space-lg);
}
.changelog-head { display: flex; align-items: baseline; gap: var(--space-sm); margin-bottom: 10px; }
.changelog-ver { font-size: 18px; font-weight: 700; color: var(--ink); }
.changelog-date { font-size: 13px; color: var(--ink-soft); }
.changelog-notes {
  margin: 0;
  font-family: var(--font);
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-soft);
  word-break: break-word;
}
.changelog-notes > :first-child { margin-top: 0; }
.changelog-notes > :last-child { margin-bottom: 0; }
.changelog-notes h2,
.changelog-notes h3 { font-size: 16px; font-weight: 700; color: var(--ink); margin: 16px 0 8px; }
.changelog-notes p { margin: 8px 0; }
.changelog-notes ul,
.changelog-notes ol { margin: 8px 0; padding-left: 22px; }
.changelog-notes li { margin: 4px 0; }
.changelog-notes strong { color: var(--ink); font-weight: 700; }
.changelog-notes code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  background: rgba(15,108,189,.08);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 1px 5px;
  font-size: 12.5px;
  color: #0f6cbd;
}
.changelog-notes a {
  color: var(--blue);
  text-decoration: none;
  border-bottom: 1px solid rgba(15,108,189,.3);
}
.changelog-notes a:hover { border-bottom-color: var(--blue); }
.changelog-notes blockquote {
  margin: 10px 0;
  padding: 8px 14px;
  border-left: 3px solid var(--line);
  background: var(--paper-2, #f5f6f8);
  border-radius: 0 6px 6px 0;
  color: var(--ink-soft);
  font-size: 13px;
}

/* 响应式 */
@media (max-width: 1024px) {
  .split-row,
  .split-row.reverse { grid-template-columns: 1fr; direction: ltr; }
  .split-row + .split-row { margin-top: var(--space-2xl); }
  .stats-row { grid-template-columns: 1fr; }
  .stat-item + .stat-item::before { display: none; }
  .stat-item { border-top: 1px solid var(--line); padding-block: var(--space-lg); }
  .stat-item:first-child { border-top: none; }
  .step-editorial { grid-template-columns: 1fr; gap: var(--space-sm); }
  .step-number { font-size: 96px; }
  .bento-2, .bento-3, .download-grid, .sys-requirements { grid-template-columns: 1fr; }
  .bento-item.wide, .bento-item.tall { grid-column: span 1; grid-row: span 1; }
  .footer-grid { grid-template-columns: 1fr; }
  .gallery-item img { height: 300px; }
}

@media (max-width: 768px) {
  :root { --gutter: 18px; }
  .nav-links { display: none; }
  .hero-content { padding-block: 140px var(--space-2xl); }
  .hero-actions { flex-direction: column; }
  .btn { width: 100%; }
  .gallery-track { padding-inline: var(--gutter); }
}

/* 暗色模式（系统偏好） */
@media (prefers-color-scheme: dark) {
  :root {
    --ink: #f3f4f6;
    --ink-soft: #a0a0a8;
    --paper: #0c0c10;
    --paper-2: #15151d;
    --surface: #1a1a22;
    --line: rgba(255,255,255,.08);
    --line-strong: rgba(255,255,255,.18);
    --blue-tint: rgba(15,108,189,.18);
  }
  .nav.scrolled {
    background: rgba(12,12,16,.92);
    box-shadow: 0 1px 0 var(--line);
  }
  .nav.scrolled .logo { color: var(--ink); }
}