/* =====================================================================
   轻转FileGo - 单页站样式
   Design Read: 单页产品站 / Windows 桌面工具用户 / Editorial 编辑杂志风
   Dials: DESIGN_VARIANCE 7 / MOTION_INTENSITY 4 / VISUAL_DENSITY 4
   基础: 无框架，原生 CSS。单一强调色（朱砂），单一圆角体系（2px）。
   ===================================================================== */

/* ---------------------------------------------------------------------
   1. 设计令牌
   --------------------------------------------------------------------- */
:root {
  /* 版面色 */
  --paper:        #f5f4f0;
  --paper-2:      #eae8e2;
  --surface:      #fbfaf8;
  --ink:          #1a1917;
  --ink-2:        #56534d;
  --ink-3:        #8c887f;
  --rule:         #dad7cf;
  --rule-strong:  #bdb9af;

  /* 唯一强调色：朱砂 */
  --accent:       #c04227;
  --accent-hover: #9e3520;
  --accent-tint:  #f2e3dd;
  --on-accent:    #fbfaf8;

  /* 半透明层（避免使用 color-mix，兼容性更稳） */
  --head-bg:  rgba(245, 244, 240, 0.88);
  --head-bg2: rgba(245, 244, 240, 0.97);
  --scrim:    rgba(245, 244, 240, 0.94);

  /* 度量 */
  --r:      2px;
  --wrap:   1200px;
  --gut:    clamp(1.25rem, 4vw, 3rem);
  --sec-y:  clamp(4rem, 9vw, 7.5rem);

  /* 字体 */
  --f-display: "Newsreader", "Songti SC", "STSong", "SimSun", "Source Han Serif SC", "Noto Serif CJK SC", Georgia, serif;
  --f-body:    -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Noto Sans SC", "Hiragino Sans GB", "Segoe UI", sans-serif;
  --f-mono:    "IBM Plex Mono", ui-monospace, SFMono-Regular, Consolas, "Courier New", monospace;

  /* 字号阶梯 */
  --fs-display: clamp(2.15rem, 5.6vw, 4.15rem);
  --fs-h2:      clamp(1.5rem, 3.1vw, 2.15rem);
  --fs-h3:      clamp(1.0625rem, 1.6vw, 1.25rem);
  --fs-body:    1rem;
  --fs-sm:      0.875rem;
  --fs-xs:      0.8125rem;
  --fs-mono:    0.75rem;

  --z-head: 40;
  --z-skip: 60;

  color-scheme: light dark;
}

html[data-theme="dark"] {
  --paper:        #131312;
  --paper-2:      #1c1b19;
  --surface:      #191817;
  --ink:          #edeae3;
  --ink-2:        #a8a49b;
  --ink-3:        #75726a;
  --rule:         #2f2d2a;
  --rule-strong:  #454139;
  --accent:       #e0704f;
  --accent-hover: #ef8d70;
  --accent-tint:  #2a1e19;
  --on-accent:    #141312;

  --head-bg:  rgba(19, 19, 18, 0.86);
  --head-bg2: rgba(19, 19, 18, 0.97);
  --scrim:    rgba(19, 19, 18, 0.92);
}

/* ---------------------------------------------------------------------
   2. 基础
   --------------------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }

/* hidden 属性必须能压过组件的 display（如 .btn 的 inline-flex） */
[hidden] { display: none !important; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

/* 横向溢出安全网：clip 不产生滚动容器，不会破坏 sticky */
html, body { overflow-x: clip; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--f-body);
  font-size: var(--fs-body);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  font-kerning: normal;
}

img, picture, svg { max-width: 100%; display: block; }
img { height: auto; }

/* 深色模式下把照片略微压暗，避免大面积高亮纸张在暗色页面里过于跳眼 */
html[data-theme="dark"] img { filter: brightness(0.9) contrast(1.03); }

h1, h2, h3, h4 {
  font-family: var(--f-display);
  font-weight: 500;
  line-height: 1.16;
  letter-spacing: -0.012em;
  margin: 0;
  text-wrap: balance;
}

p { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }

a { color: inherit; text-decoration: none; }

em { font-style: italic; }

/* 焦点可见：键盘导航必须看得见 */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: var(--r);
}

.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gut);
}

.skip-link {
  position: absolute;
  left: 0.75rem;
  top: -4rem;
  z-index: var(--z-skip);
  background: var(--ink);
  color: var(--paper);
  padding: 0.6rem 0.9rem;
  font-size: var(--fs-sm);
  transition: top 160ms ease-out;
}
.skip-link:focus { top: 0.75rem; }

/* 小号等宽标签（全站限量使用，不滥用眉标） */
.mono {
  font-family: var(--f-mono);
  font-size: var(--fs-mono);
  letter-spacing: 0.04em;
  color: var(--ink-3);
}

/* ---------------------------------------------------------------------
   3. 报头
   --------------------------------------------------------------------- */
.masthead {
  position: sticky;
  top: 0;
  z-index: var(--z-head);
  background: var(--head-bg);
  border-bottom: 1px solid var(--rule);
  transition: background 200ms ease-out, border-color 200ms ease-out;
}
@supports (backdrop-filter: blur(1px)) {
  .masthead { backdrop-filter: saturate(1.4) blur(10px); }
}
.masthead[data-stuck="true"] {
  border-bottom-color: var(--rule-strong);
  background: var(--head-bg2);
}

.masthead__inner {
  display: flex;
  align-items: center;
  gap: clamp(1rem, 3vw, 2.5rem);
  min-height: 64px;
}

.brand {
  display: inline-flex;
  align-items: baseline;
  gap: 0.5rem;
  font-family: var(--f-display);
  font-size: 1.1875rem;
  letter-spacing: -0.01em;
  white-space: nowrap;
}
.brand__mark {
  display: inline-grid;
  place-items: center;
  width: 1.625rem;
  height: 1.625rem;
  background: var(--accent);
  color: var(--on-accent);
  border-radius: var(--r);
  font-size: 0.9375rem;
  font-weight: 600;
  transform: translateY(0.1875rem);
}
.brand__alt { color: var(--ink-2); font-size: 0.9375rem; letter-spacing: 0.01em; }

.nav {
  display: flex;
  align-items: center;
  gap: clamp(1rem, 2.4vw, 2rem);
  margin-left: auto;
  font-size: var(--fs-sm);
}
.nav a {
  color: var(--ink-2);
  padding-block: 0.35rem;
  border-bottom: 1px solid transparent;
  transition: color 160ms ease-out, border-color 160ms ease-out;
}
.nav a:hover { color: var(--ink); border-bottom-color: var(--accent); }

.masthead__tools { display: flex; align-items: center; gap: 0.5rem; }

.icon-btn {
  display: inline-grid;
  place-items: center;
  width: 40px;
  height: 40px;
  background: transparent;
  border: 1px solid var(--rule);
  border-radius: var(--r);
  color: var(--ink-2);
  cursor: pointer;
  transition: background 160ms ease-out, color 160ms ease-out, border-color 160ms ease-out;
}
.icon-btn:hover { background: var(--paper-2); color: var(--ink); border-color: var(--rule-strong); }
.icon-btn:active { transform: translateY(1px); }
.icon-btn svg { width: 18px; height: 18px; }

.theme-toggle .i-moon { display: none; }
html[data-theme="dark"] .theme-toggle .i-moon { display: block; }
html[data-theme="dark"] .theme-toggle .i-sun { display: none; }

.nav-toggle { display: none; }

/* ---------------------------------------------------------------------
   4. Hero
   --------------------------------------------------------------------- */
.hero { padding-block: clamp(2.5rem, 6vw, 4.5rem) clamp(3rem, 7vw, 6rem); }

.hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: clamp(2rem, 5vw, 4.5rem);
  align-items: center;
}

.hero__title {
  font-size: var(--fs-display);
  letter-spacing: -0.02em;
  margin-bottom: 1.25rem;
}
.hero__title em { color: var(--accent); font-style: italic; }

/* 斜体 + 降部字母：留出降部空隙，避免被裁切 */
.hero__title em { padding-bottom: 0.06em; line-height: 1.1; display: inline-block; }

.hero__lede {
  max-width: 34ch;
  color: var(--ink-2);
  font-size: clamp(1rem, 1.35vw, 1.0625rem);
  line-height: 1.75;
}

.hero__cta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 2rem;
}

.hero__figure { margin: 0; position: relative; }
.hero__figure img {
  width: 100%;
  aspect-ratio: 2 / 3;
  object-fit: cover;
  border-radius: var(--r);
  background: var(--paper-2);
}

/* ---------------------------------------------------------------------
   5. 按钮
   --------------------------------------------------------------------- */
.btn {
  --btn-bg: var(--accent);
  --btn-fg: var(--on-accent);
  --btn-bd: var(--accent);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  min-height: 46px;
  padding: 0.7rem 1.35rem;
  background: var(--btn-bg);
  color: var(--btn-fg);
  border: 1px solid var(--btn-bd);
  border-radius: var(--r);
  font-family: var(--f-body);
  font-size: var(--fs-sm);
  font-weight: 500;
  white-space: nowrap;
  cursor: pointer;
  transition: background 160ms ease-out, border-color 160ms ease-out, color 160ms ease-out;
}
.btn:hover { background: var(--accent-hover); border-color: var(--accent-hover); }
.btn:active { transform: translateY(1px); }
.btn[disabled], .btn[aria-disabled="true"] { opacity: 0.4; pointer-events: none; }

.btn--ghost {
  --btn-bg: transparent;
  --btn-fg: var(--ink);
  --btn-bd: var(--rule-strong);
}
.btn--ghost:hover { background: var(--paper-2); border-color: var(--ink-3); }

.btn--sm { min-height: 38px; padding: 0.45rem 0.85rem; font-size: var(--fs-xs); }

.link-quiet {
  color: var(--ink-2);
  font-size: var(--fs-sm);
  border-bottom: 1px solid var(--rule-strong);
  transition: color 160ms ease-out, border-color 160ms ease-out;
}
.link-quiet:hover { color: var(--accent); border-bottom-color: var(--accent); }

/* ---------------------------------------------------------------------
   6. 通用区块
   --------------------------------------------------------------------- */
.section { padding-block: var(--sec-y); border-top: 1px solid var(--rule); }

.section__head { max-width: 42ch; margin-bottom: clamp(2rem, 4vw, 3rem); }
.section__title { font-size: var(--fs-h2); }
.section__note { margin-top: 0.85rem; color: var(--ink-2); font-size: var(--fs-sm); line-height: 1.75; }

/* ---------------------------------------------------------------------
   7. 格式跑马灯（全站仅此一处）
   --------------------------------------------------------------------- */
.formats { padding-block: clamp(1.75rem, 3.5vw, 2.5rem); border-top: 1px solid var(--rule); }
.formats__label { margin-bottom: 1rem; }

.marquee {
  position: relative;
  overflow: hidden;
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 6%, #000 94%, transparent);
  mask-image: linear-gradient(90deg, transparent, #000 6%, #000 94%, transparent);
}
.marquee__track {
  display: flex;
  width: max-content;
  gap: 0;
  animation: slide 42s linear infinite;
}
.marquee:hover .marquee__track { animation-play-state: paused; }
.marquee__item {
  font-family: var(--f-display);
  font-size: clamp(1.05rem, 2vw, 1.5rem);
  color: var(--ink);
  padding-inline: clamp(0.9rem, 2vw, 1.6rem);
  border-right: 1px solid var(--rule);
  line-height: 1.5;
  white-space: nowrap;
}
@keyframes slide {
  from { transform: translate3d(0, 0, 0); }
  to   { transform: translate3d(-50%, 0, 0); }
}

/* ---------------------------------------------------------------------
   8. 能力（非对称 bento，单元格数 = 内容条数）
   --------------------------------------------------------------------- */
.bento {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
  border-radius: var(--r);
  overflow: hidden;
}
.bento__cell {
  background: var(--surface);
  padding: clamp(1.35rem, 2.6vw, 2.1rem);
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}
.bento__cell h3 { font-size: var(--fs-h3); }
.bento__cell p { color: var(--ink-2); font-size: var(--fs-sm); line-height: 1.7; max-width: 40ch; }

.bento__cell--wide { grid-column: span 4; }
.bento__cell--half { grid-column: span 2; }
.bento__cell--third { grid-column: span 3; }
.bento__cell--tint { background: var(--accent-tint); }

/* 至少两格有真实视觉变化：一格用真实图片做底 */
.bento__cell--photo {
  position: relative;
  justify-content: flex-end;
  min-height: 15rem;
  padding: 0;
  overflow: hidden;
}
.bento__cell--photo img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.bento__cell--photo .bento__photo-body {
  position: relative;
  padding: clamp(1.35rem, 2.6vw, 2.1rem);
  background: linear-gradient(to top, var(--scrim) 36%, transparent);
  width: 100%;
}

/* ---------------------------------------------------------------------
   9. 使用流程（图 + 三步）
   --------------------------------------------------------------------- */
.flow__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: clamp(2rem, 5vw, 4.5rem);
  align-items: center;
}
.flow__figure { margin: 0; }
.flow__figure img { width: 100%; aspect-ratio: 3 / 2; object-fit: cover; border-radius: var(--r); background: var(--paper-2); }

.flow__list { display: grid; gap: 1.6rem; }
.flow__step { display: grid; grid-template-columns: auto 1fr; gap: 1rem; align-items: start; }
.flow__step-num {
  font-family: var(--f-mono);
  font-size: var(--fs-mono);
  color: var(--accent);
  padding-top: 0.45rem;
  min-width: 1.75rem;
}
.flow__step h3 { font-size: var(--fs-h3); margin-bottom: 0.3rem; }
.flow__step p { color: var(--ink-2); font-size: var(--fs-sm); line-height: 1.7; }

/* ---------------------------------------------------------------------
   10. 下载
   --------------------------------------------------------------------- */
.dl-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(1rem, 2.5vw, 1.75rem);
}
.dl-card {
  display: flex;
  flex-direction: column;
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--r);
  padding: clamp(1.4rem, 2.6vw, 2rem);
}
.dl-card__top { display: flex; align-items: baseline; justify-content: space-between; gap: 1rem; }
.dl-card h3 { font-size: var(--fs-h3); }
.dl-card__arch { font-family: var(--f-mono); font-size: var(--fs-mono); color: var(--ink-3); }
.dl-card__use { margin-top: 0.7rem; color: var(--ink-2); font-size: var(--fs-sm); line-height: 1.7; }

.dl-meta {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.75rem 1rem;
  margin: 1.35rem 0;
  padding-top: 1.1rem;
  border-top: 1px solid var(--rule);
}
.dl-meta dt { font-family: var(--f-mono); font-size: var(--fs-mono); color: var(--ink-3); margin-bottom: 0.15rem; }
.dl-meta dd { margin: 0; font-size: var(--fs-sm); }

.dl-card__actions { display: flex; flex-wrap: wrap; align-items: center; gap: 0.75rem; margin-top: auto; }

.hash {
  margin-top: 1.1rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex-wrap: wrap;
}
.hash__code {
  font-family: var(--f-mono);
  font-size: 0.6875rem;
  color: var(--ink-2);
  background: var(--paper-2);
  border: 1px solid var(--rule);
  border-radius: var(--r);
  padding: 0.3rem 0.5rem;
  word-break: break-all;
  flex: 1 1 14rem;
}
.copy-btn {
  background: transparent;
  border: 1px solid var(--rule);
  border-radius: var(--r);
  color: var(--ink-2);
  font-family: var(--f-body);
  font-size: var(--fs-xs);
  padding: 0.35rem 0.65rem;
  cursor: pointer;
  transition: background 160ms ease-out, color 160ms ease-out, border-color 160ms ease-out;
}
.copy-btn:hover { background: var(--paper-2); color: var(--ink); border-color: var(--rule-strong); }
.copy-btn[data-state="done"] { color: var(--accent); border-color: var(--accent); }

.dl-note {
  margin-top: clamp(1.5rem, 3vw, 2.25rem);
  padding: 1.1rem 1.25rem;
  border: 1px solid var(--rule);
  border-left: 2px solid var(--accent);
  border-radius: var(--r);
  background: var(--paper-2);
  font-size: var(--fs-sm);
  color: var(--ink-2);
  line-height: 1.75;
}
.dl-note strong { color: var(--ink); font-weight: 500; }

/* ---------------------------------------------------------------------
   11. 要求与说明（分组，不给每行加边框）
   --------------------------------------------------------------------- */
.req-groups {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(1.75rem, 4vw, 3rem);
}
.req-group h3 { font-size: var(--fs-h3); padding-bottom: 0.75rem; border-bottom: 1px solid var(--rule-strong); margin-bottom: 1rem; }
.req-group li { padding-block: 0.55rem; font-size: var(--fs-sm); color: var(--ink-2); line-height: 1.7; }
.req-group li + li { border-top: 1px solid var(--rule); }
.req-group li b { color: var(--ink); font-weight: 500; }

/* 屏幕阅读器可见、视觉隐藏 */
.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

/* 命中用户系统架构时的高亮（真实语义，避免装饰性角标） */
.dl-card[data-match="true"] {
  border-color: var(--accent);
  box-shadow: inset 0 0 0 1px var(--accent);
}

/* ---------------------------------------------------------------------
   12. 常见问题
   --------------------------------------------------------------------- */
.faq { display: grid; gap: 0; }
.faq__item { border-top: 1px solid var(--rule); }
.faq__item:last-child { border-bottom: 1px solid var(--rule); }
.faq__q {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  width: 100%;
  padding: 1.25rem 0;
  background: none;
  border: 0;
  color: var(--ink);
  font-family: var(--f-display);
  font-size: var(--fs-h3);
  text-align: left;
  cursor: pointer;
  list-style: none;
}
.faq__q::-webkit-details-marker { display: none; }
.faq__q:hover { color: var(--accent); }
.faq__sign { flex: none; position: relative; width: 14px; height: 14px; }
.faq__sign::before, .faq__sign::after {
  content: ""; position: absolute; inset: 50% 0 auto 0; height: 1.5px; background: currentColor;
}
.faq__sign::after { transform: rotate(90deg); transition: transform 200ms ease-out; }
.faq__item[open] .faq__sign::after { transform: rotate(0deg); }
.faq__a { padding: 0 0 1.35rem; max-width: 66ch; color: var(--ink-2); font-size: var(--fs-sm); line-height: 1.8; }

/* ---------------------------------------------------------------------
   12. 运行库与依赖
   --------------------------------------------------------------------- */
.deps { display: grid; gap: clamp(2rem, 4.5vw, 3.25rem); }

.deps__title {
  font-size: var(--fs-h3);
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--rule-strong);
  margin-bottom: 1rem;
}
.deps__lead {
  max-width: 64ch;
  margin-bottom: 0.85rem;
  color: var(--ink-2);
  font-size: var(--fs-sm);
  line-height: 1.75;
}

/* 已内置：紧凑清单 */
.deps__plain li {
  padding-block: 0.6rem;
  font-size: var(--fs-sm);
  color: var(--ink-2);
  line-height: 1.75;
}
.deps__plain li + li { border-top: 1px solid var(--rule); }
.deps__plain .mono {
  color: var(--ink);
  font-size: var(--fs-xs);
  margin-right: 0.55rem;
}

/* 需要下载的依赖：说明在左，下载入口在右 */
.deps__list { border-top: 1px solid var(--rule); }
.dep {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 0.9rem 1.75rem;
  padding-block: 1.1rem;
  border-bottom: 1px solid var(--rule);
}
.dep__name {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.6rem;
  color: var(--ink);
  font-weight: 500;
}
.dep__tag {
  padding: 0.1rem 0.45rem;
  border: 1px solid var(--rule);
  border-radius: var(--r);
  color: var(--ink-3);
  font-family: var(--f-mono);
  font-size: var(--fs-mono);
  font-weight: 400;
  letter-spacing: 0.04em;
}
.dep__desc {
  max-width: 62ch;
  margin-top: 0.35rem;
  color: var(--ink-2);
  font-size: var(--fs-sm);
  line-height: 1.7;
}

/* ---------------------------------------------------------------------
   13. 页脚
   --------------------------------------------------------------------- */
.foot { border-top: 1px solid var(--rule); padding-block: clamp(2.5rem, 5vw, 3.5rem); }
.foot__grid { display: flex; flex-wrap: wrap; gap: 2rem; justify-content: space-between; align-items: flex-start; }
.foot__brand { max-width: 30ch; }
.foot__brand p { margin-top: 0.75rem; color: var(--ink-2); font-size: var(--fs-sm); line-height: 1.75; }
.foot__links { display: flex; flex-wrap: wrap; gap: 1.5rem; font-size: var(--fs-sm); }
.foot__links a { color: var(--ink-2); border-bottom: 1px solid transparent; transition: color 160ms ease-out, border-color 160ms ease-out; }
.foot__links a:hover { color: var(--ink); border-bottom-color: var(--accent); }
.foot__legal { margin-top: 2.25rem; padding-top: 1.25rem; border-top: 1px solid var(--rule); font-size: var(--fs-xs); color: var(--ink-3); }

/* ---------------------------------------------------------------------
   14. 进场动效（MOTION_INTENSITY 4：克制的滚动揭示）
   --------------------------------------------------------------------- */
/* 仅当 JS 可用时才启用进场动效：无 JS 环境下内容必须照常可见 */
.js .reveal { opacity: 0; transform: translate3d(0, 14px, 0); }
.js .reveal.is-in {
  opacity: 1;
  transform: none;
  transition: opacity 520ms cubic-bezier(0.16, 1, 0.3, 1), transform 520ms cubic-bezier(0.16, 1, 0.3, 1);
}
.js .reveal[data-delay="1"].is-in { transition-delay: 70ms; }
.js .reveal[data-delay="2"].is-in { transition-delay: 140ms; }
.js .reveal[data-delay="3"].is-in { transition-delay: 210ms; }

/* ---------------------------------------------------------------------
   15. 响应式（移动端折叠逐块显式声明）
   --------------------------------------------------------------------- */
@media (max-width: 1023px) {
  .hero__grid { grid-template-columns: minmax(0, 1fr); gap: 2.25rem; }
  .hero__figure { order: -1; }
  .hero__figure img { aspect-ratio: 16 / 10; }
  .bento { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .bento__cell--wide, .bento__cell--third { grid-column: span 2; }
  .flow__grid { grid-template-columns: minmax(0, 1fr); }
  .flow__figure { order: 2; }
  .req-groups { grid-template-columns: minmax(0, 1fr); }
}

@media (max-width: 767px) {
  .nav { display: none; }
  .nav.is-open {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    margin: 0;
    padding: 0.5rem var(--gut) 1rem;
    background: var(--paper);
    border-bottom: 1px solid var(--rule);
  }
  .nav.is-open a { width: 100%; padding-block: 0.8rem; border-bottom: 1px solid var(--rule); }
  .masthead__inner { position: relative; }
  .nav-toggle { display: inline-grid; }

  .bento { grid-template-columns: minmax(0, 1fr); }
  .bento__cell--wide, .bento__cell--half, .bento__cell--third { grid-column: span 1; }
  .dl-grid { grid-template-columns: minmax(0, 1fr); }
  .dl-meta { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .dep { grid-template-columns: minmax(0, 1fr); align-items: start; }
  .dep .btn { justify-self: start; }
  .hero__cta .btn { flex: 1 1 auto; }
  .foot__grid { flex-direction: column; }
}

/* ---------------------------------------------------------------------
   16. 降低动效偏好（强制）
   --------------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .js .reveal, .reveal { opacity: 1; transform: none; }
  .js .reveal.is-in { transition: none; }
  .marquee__track { animation: none; }
  .marquee { overflow-x: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
}