/* ============================================================
   麻将胡了棋牌 · 共享站点样式 /assets/site.css
   牌桌江湖：深墨绿牌桌 / 象牙白牌面 / 竹青目录 / 鎏金刻度 / 朱砂动作
   ============================================================ */

/* ---------- 1. 变量 ---------- */
:root {
  --mat: #0E2B24;
  --mat-deep: #0A1F1A;
  --char: #141312;
  --char-soft: #1E1C1A;
  --ink: #16130F;
  --ivory: #F3EBDD;
  --ivory-dim: #E3D8C5;
  --bamboo: #5E8C6A;
  --bamboo-light: #A8C3AE;
  --cinnabar: #B23A2F;
  --cinnabar-deep: #8E2C24;
  --gold: #C9A227;
  --tea: #6B4F3A;
  --stone: #9A9488;

  --line: rgba(243, 235, 221, 0.14);
  --line-strong: rgba(243, 235, 221, 0.3);
  --shadow-hard: 6px 6px 0 rgba(0, 0, 0, 0.5);
  --shadow-soft: 0 22px 46px -30px rgba(0, 0, 0, 0.95);

  --radius-tile: 8px;
  --radius-ui: 4px;

  --shell: min(1240px, 100% - clamp(1.25rem, 5vw, 4.5rem));
  --gutter: clamp(0.75rem, 1.6vw, 1.5rem);
  --header-h: 84px;

  --font-display: "Songti SC", "STSong", "SimSun", "Source Han Serif SC", "Noto Serif CJK SC", serif;
  --font-body: "PingFang SC", "Source Han Sans SC", "Microsoft YaHei", "Hiragino Sans GB", system-ui, sans-serif;
  --font-mono: ui-monospace, "SFMono-Regular", Menlo, Consolas, "Courier New", monospace;

  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

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

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

body,
h1, h2, h3, h4, h5, p,
figure, blockquote, dl, dd, ol, ul, pre { margin: 0; }

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

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

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

button { font: inherit; color: inherit; background: none; border: 0; }

table { border-collapse: collapse; }

:focus-visible {
  outline: 3px solid var(--gold);
  outline-offset: 3px;
  border-radius: 2px;
}

/* ---------- 3. 基础排版 ---------- */
body {
  min-height: 100vh;
  background-color: var(--mat);
  background-image:
    repeating-linear-gradient(180deg, rgba(243, 235, 221, 0.022) 0 2px, transparent 2px 5px),
    radial-gradient(120% 80% at 88% -12%, rgba(94, 140, 106, 0.3), transparent 62%),
    radial-gradient(90% 62% at -6% 4%, rgba(107, 79, 58, 0.34), transparent 58%),
    linear-gradient(180deg, #0E2B24 0%, #10241F 40%, #141312 100%);
  background-attachment: fixed;
  color: var(--ivory);
  font-family: var(--font-body);
  font-size: clamp(1rem, 0.96rem + 0.22vw, 1.0625rem);
  line-height: 1.8;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.16;
  letter-spacing: 0.012em;
  color: var(--ivory);
}

h2 { font-size: clamp(1.75rem, 1.3rem + 2vw, 2.85rem); }
h3 { font-size: clamp(1.22rem, 1.08rem + 0.8vw, 1.6rem); }
h4 { font-size: clamp(1.02rem, 0.98rem + 0.3vw, 1.18rem); }

.display-title {
  font-family: var(--font-display);
  font-size: clamp(2.35rem, 1.5rem + 4.4vw, 4.6rem);
  font-weight: 900;
  line-height: 1.05;
  letter-spacing: 0.02em;
}

.lede {
  max-width: 60ch;
  font-size: clamp(1.02rem, 0.98rem + 0.5vw, 1.28rem);
  line-height: 1.75;
  color: var(--ivory-dim);
}

.body-text { max-width: 68ch; }

.mono {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--bamboo-light);
}

.eyebrow::before {
  content: "";
  width: 0.5rem;
  height: 0.5rem;
  background: var(--gold);
  border-radius: 1px;
}

.vlabel {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.34em;
  color: var(--stone);
}

a:hover { color: var(--gold); }

/* ---------- 4. 容器与分区 ---------- */
.shell {
  width: var(--shell);
  margin-inline: auto;
}

.band {
  position: relative;
  padding-block: clamp(2.75rem, 6vw, 5.25rem);
}

.band--mat { background: linear-gradient(180deg, rgba(14, 43, 36, 0.92), rgba(14, 43, 36, 0.5)); }
.band--char { background: linear-gradient(180deg, rgba(20, 19, 18, 0.96), rgba(20, 19, 18, 0.84)); }
.band--tea { background: linear-gradient(180deg, rgba(107, 79, 58, 0.32), rgba(20, 19, 18, 0.92)); }

.band--ivory {
  background: var(--ivory);
  color: var(--ink);
}

.band--ivory h2,
.band--ivory h3,
.band--ivory h4 { color: var(--ink); }
.band--ivory .lede,
.band--ivory .body-text { color: #3C362C; }
.band--ivory .eyebrow { color: var(--cinnabar-deep); }
.band--ivory .vlabel { color: #6B6154; }

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 0.85rem 1.75rem;
  padding-bottom: 1rem;
  margin-bottom: clamp(1.5rem, 3vw, 2.5rem);
  border-bottom: 2px solid var(--tea);
}

.section-head > * { min-width: 0; }

.stack { display: grid; gap: clamp(0.85rem, 1.6vw, 1.25rem); }

.rule {
  height: 2px;
  border: 0;
  background: repeating-linear-gradient(90deg, var(--tea) 0 10px, transparent 10px 20px);
  margin-block: clamp(1.25rem, 3vw, 2rem);
}

/* ---------- 5. 栅格 ---------- */
.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--gutter);
}

.col-3 { grid-column: span 3; }
.col-4 { grid-column: span 4; }
.col-5 { grid-column: span 5; }
.col-6 { grid-column: span 6; }
.col-7 { grid-column: span 7; }
.col-8 { grid-column: span 8; }
.col-9 { grid-column: span 9; }
.col-12 { grid-column: span 12; }
.start-2 { grid-column-start: 2; }
.start-7 { grid-column-start: 7; }

/* ---------- 6. 面板与牌面 ---------- */
.panel {
  background: linear-gradient(180deg, rgba(243, 235, 221, 0.06), rgba(243, 235, 221, 0.018));
  border: 2px solid var(--tea);
  border-radius: var(--radius-tile);
  padding: clamp(1.1rem, 2.4vw, 1.8rem);
  box-shadow: var(--shadow-hard);
}

.panel--tile {
  background: var(--ivory);
  color: var(--ink);
  border-color: var(--tea);
}

.panel--tile h2,
.panel--tile h3,
.panel--tile h4 { color: var(--ink); }
.panel--tile .lede,
.panel--tile .body-text { color: #3C362C; }

.panel__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding-bottom: 0.6rem;
  margin-bottom: 0.9rem;
  border-bottom: 1px dashed var(--line-strong);
}

.panel--tile .panel__head { border-bottom-color: rgba(22, 19, 15, 0.24); }

.panel__body { min-width: 0; }

.tile {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 2.5rem;
  padding: 0.3rem 0.6rem;
  background: var(--ivory);
  color: var(--ink);
  border: 2px solid var(--tea);
  border-radius: 6px;
  font-family: var(--font-display);
  font-weight: 900;
  line-height: 1.2;
  box-shadow: 3px 3px 0 rgba(0, 0, 0, 0.45);
}

.tile--gold { background: var(--gold); color: #241D05; border-color: #8C6F14; }
.tile--red { background: var(--cinnabar); color: var(--ivory); border-color: var(--cinnabar-deep); }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.22rem 0.62rem;
  border: 1px solid var(--bamboo);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  color: var(--bamboo-light);
  white-space: nowrap;
}

.tag--gold { color: var(--gold); border-color: rgba(201, 162, 39, 0.75); }
.tag--red { color: #EAA9A1; border-color: rgba(178, 58, 47, 0.8); }

/* ---------- 7. 牌墙与手牌 ---------- */
.tile-wall {
  display: flex;
  gap: clamp(0.75rem, 1.5vw, 1.25rem);
  overflow-x: auto;
  padding: 0.35rem 0.35rem 1.15rem;
  scroll-snap-type: x mandatory;
  scrollbar-color: var(--bamboo) transparent;
  -webkit-overflow-scrolling: touch;
}

.tile-wall__item {
  flex: 0 0 clamp(240px, 26vw, 320px);
  scroll-snap-align: start;
}

.hand-column {
  display: grid;
  gap: 0.9rem;
  align-content: start;
}

/* ---------- 8. 图例与目录 ---------- */
.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem 1.2rem;
  font-family: var(--font-mono);
  font-size: 0.73rem;
  letter-spacing: 0.1em;
  color: var(--stone);
}

.legend__item { display: inline-flex; align-items: center; gap: 0.45rem; }

.legend__dot {
  width: 0.7rem;
  height: 0.7rem;
  border-radius: 2px;
  background: var(--bamboo);
  box-shadow: inset 0 0 0 1px rgba(0, 0, 0, 0.35);
}

.legend__dot--gold { background: var(--gold); }
.legend__dot--red { background: var(--cinnabar); }
.legend__dot--stone { background: var(--stone); }

.toc {
  position: sticky;
  top: calc(var(--header-h) + 1rem);
  display: grid;
  gap: 0.15rem;
  padding-left: 0.9rem;
  border-left: 2px solid var(--tea);
}

.toc__link {
  display: block;
  padding: 0.35rem 0;
  font-size: 0.88rem;
  color: var(--stone);
  border-bottom: 1px solid transparent;
  transition: color 0.16s var(--ease), border-color 0.16s var(--ease);
}

.toc__link:hover { color: var(--ivory); border-bottom-color: var(--line-strong); }

.toc__link[aria-current="true"] {
  color: var(--gold);
  font-weight: 600;
  border-bottom-color: rgba(201, 162, 39, 0.5);
}

.toc__link[aria-current="true"]::before {
  content: "◤";
  margin-right: 0.4rem;
  font-size: 0.68rem;
  color: var(--cinnabar);
}

/* ---------- 9. 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.45rem;
  padding-block: 0.9rem;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.08em;
  color: var(--stone);
}

.breadcrumb__link {
  color: var(--bamboo-light);
  border-bottom: 1px solid transparent;
}

.breadcrumb__link:hover { color: var(--ivory); border-bottom-color: var(--gold); }

.breadcrumb__sep { color: var(--tea); }

.breadcrumb__current { color: var(--ivory); }

/* ---------- 10. 图片容器 ---------- */
.media {
  position: relative;
  overflow: hidden;
  aspect-ratio: var(--media-ratio, 16 / 10);
  border: 2px solid var(--tea);
  border-radius: var(--radius-tile);
  background:
    radial-gradient(120% 90% at 20% 0%, rgba(94, 140, 106, 0.32), transparent 62%),
    linear-gradient(140deg, #17281F, #0B1310 70%);
  box-shadow: var(--shadow-hard);
}

.media__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.94) contrast(1.03);
}

.media__caption {
  position: absolute;
  inset: auto 0 0 0;
  padding: 0.6rem 0.8rem;
  font-family: var(--font-mono);
  font-size: 0.71rem;
  letter-spacing: 0.06em;
  color: var(--ivory);
  background: linear-gradient(0deg, rgba(10, 10, 9, 0.88), transparent);
}

.media--cinema { --media-ratio: 21 / 9; }
.media--wide { --media-ratio: 16 / 9; }
.media--tile { --media-ratio: 1 / 1; }
.media--portrait { --media-ratio: 3 / 4; }

/* ---------- 11. 提示与引用 ---------- */
.note {
  padding-left: 0.85rem;
  border-left: 3px solid var(--bamboo);
  font-size: 0.86rem;
  line-height: 1.75;
  color: var(--stone);
}

.band--ivory .note { color: #574E42; border-left-color: var(--cinnabar); }

.quote {
  padding-left: 1rem;
  border-left: 4px solid var(--cinnabar);
  font-family: var(--font-display);
  font-size: clamp(1.16rem, 1.05rem + 0.7vw, 1.6rem);
  line-height: 1.62;
  color: var(--ivory);
}

/* ---------- 12. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  padding: 0.7rem 1.1rem;
  border: 2px solid transparent;
  border-radius: var(--radius-ui);
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 600;
  line-height: 1;
  letter-spacing: 0.04em;
  text-align: center;
  cursor: pointer;
  transition: transform 0.18s var(--ease), box-shadow 0.18s var(--ease),
    background-color 0.18s var(--ease), color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.btn--primary {
  background: var(--cinnabar);
  color: var(--ivory);
  border-color: var(--cinnabar-deep);
  box-shadow: 4px 4px 0 rgba(0, 0, 0, 0.5);
}

.btn--primary:hover {
  background: var(--cinnabar-deep);
  color: var(--ivory);
  transform: translate(-1px, -2px);
  box-shadow: 6px 6px 0 rgba(0, 0, 0, 0.5);
}

.btn--ghost {
  background: transparent;
  color: var(--bamboo-light);
  border-color: var(--bamboo);
}

.btn--ghost:hover {
  color: var(--ivory);
  border-color: var(--bamboo-light);
  background: rgba(94, 140, 106, 0.18);
  transform: translateY(-1px);
}

.btn--sm { padding: 0.55rem 0.85rem; font-size: 0.8rem; }

/* ---------- 13. 跳转与进度 ---------- */
.skip-link {
  position: absolute;
  left: 1rem;
  top: -4.5rem;
  z-index: 200;
  padding: 0.6rem 1rem;
  background: var(--ivory);
  color: var(--ink);
  border: 2px solid var(--tea);
  border-radius: var(--radius-ui);
  font-weight: 700;
  transition: top 0.18s var(--ease);
}

.skip-link:focus { top: 0.6rem; }

/* ---------- 14. 头部 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  color: var(--ivory);
  background: linear-gradient(180deg, rgba(11, 31, 26, 0.98), rgba(11, 31, 26, 0.9));
  border-bottom: 2px solid var(--tea);
  box-shadow: 0 18px 34px -28px #000;
}

.scroll-meter {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 3px;
  overflow: hidden;
  background: rgba(243, 235, 221, 0.09);
}

.scroll-meter__bar {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(var(--progress, 0));
  transform-origin: left center;
  background: linear-gradient(90deg, var(--bamboo), var(--gold) 58%, var(--cinnabar));
  transition: transform 0.12s linear;
}

.header-inner {
  position: relative;
  width: var(--shell);
  margin-inline: auto;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: clamp(0.75rem, 2.5vw, 2rem);
  padding-block: clamp(0.6rem, 1.4vw, 1rem);
}

.brand { display: inline-flex; align-items: center; gap: 0.7rem; }

.brand:hover .brand__tile { background: var(--cinnabar); border-color: var(--cinnabar-deep); }

.brand__tile {
  display: grid;
  place-items: center;
  width: 44px;
  height: 52px;
  background: var(--bamboo);
  color: var(--ivory);
  border: 2px solid var(--tea);
  border-radius: 6px;
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 900;
  line-height: 1;
  box-shadow: inset 0 0 0 3px rgba(243, 235, 221, 0.18), 3px 3px 0 rgba(0, 0, 0, 0.45);
  transition: background-color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.brand__text { display: grid; line-height: 1.12; }

.brand__name {
  font-family: var(--font-display);
  font-size: clamp(1.05rem, 1rem + 0.45vw, 1.3rem);
  font-weight: 900;
  letter-spacing: 0.14em;
  color: var(--ivory);
}

.brand__sub {
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.34em;
  color: var(--stone);
}

.version-badge {
  justify-self: center;
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  padding: 0.28rem 0.7rem 0.28rem 0.28rem;
  border: 1px solid rgba(201, 162, 39, 0.45);
  border-radius: 999px;
  background: rgba(201, 162, 39, 0.08);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  color: var(--stone);
  white-space: nowrap;
}

.version-badge__tag {
  font-family: var(--font-mono);
  font-weight: 700;
  letter-spacing: 0.06em;
  color: #1E1704;
  background: var(--gold);
  border-radius: 999px;
  padding: 0.14rem 0.5rem;
}

.version-badge__note { color: var(--bamboo-light); font-size: 0.7rem; }

.nav-toggle { display: none; }

.nav-toggle__bars {
  display: grid;
  gap: 4px;
  width: 18px;
}

.nav-toggle__bars i {
  display: block;
  height: 2px;
  background: currentColor;
  transition: transform 0.2s var(--ease), opacity 0.2s var(--ease);
}

.nav-toggle__label {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.2em;
}

.header-right {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: clamp(0.75rem, 2vw, 1.6rem);
  min-width: 0;
}

.site-nav__list {
  display: flex;
  align-items: center;
  gap: clamp(0.35rem, 1.2vw, 0.9rem);
}

.site-nav__link {
  position: relative;
  display: inline-block;
  padding: 0.45rem 0.35rem;
  font-size: 0.9rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--ivory-dim);
  border-bottom: 2px solid transparent;
  transition: color 0.16s var(--ease), border-color 0.16s var(--ease);
}

.site-nav__link:hover { color: var(--ivory); border-bottom-color: var(--gold); }

.site-nav__link[aria-current="page"] {
  color: var(--ivory);
  border-bottom-color: var(--cinnabar);
}

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

/* ---------- 15. 页脚 ---------- */
.site-footer {
  position: relative;
  padding-block: clamp(2.25rem, 5vw, 4rem) 1.25rem;
  background: linear-gradient(180deg, #171513 0%, #0B0A09 100%);
  border-top: 3px solid var(--tea);
  color: var(--ivory);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  opacity: 0.5;
  background: repeating-linear-gradient(90deg, var(--gold) 0 16px, transparent 16px 32px);
}

.footer-inner {
  width: var(--shell);
  margin-inline: auto;
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(0, 0.85fr) minmax(0, 1.1fr);
  gap: clamp(1.5rem, 4vw, 3rem);
  align-items: start;
}

.footer-brand__mark {
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 1.2rem + 0.9vw, 1.9rem);
  font-weight: 900;
  letter-spacing: 0.1em;
  color: var(--ivory);
}

.footer-brand__mark span {
  display: block;
  margin-top: 0.45rem;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 400;
  letter-spacing: 0.4em;
  color: var(--stone);
}

.footer-brand__line {
  margin-top: 0.85rem;
  font-size: 0.95rem;
  letter-spacing: 0.04em;
  color: var(--bamboo-light);
}

.footer-brand__note {
  margin-top: 0.7rem;
  max-width: 34ch;
  font-size: 0.8rem;
  line-height: 1.7;
  color: var(--stone);
}

.footer-seal {
  display: inline-grid;
  place-items: center;
  margin-top: 1rem;
  width: 3.1rem;
  height: 3.1rem;
  border: 2px solid var(--cinnabar);
  border-radius: 6px;
  color: #D0665A;
  font-family: var(--font-display);
  font-size: 0.76rem;
  line-height: 1.15;
  letter-spacing: 0.06em;
  text-align: center;
  transform: rotate(-4deg);
  box-shadow: inset 0 0 0 2px rgba(178, 58, 47, 0.28);
}

.footer-nav__title,
.footer-contact__title {
  margin-bottom: 0.9rem;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--gold);
}

.footer-nav__list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.35rem 0.9rem;
}

.footer-link {
  display: inline-block;
  padding-block: 0.15rem;
  font-size: 0.88rem;
  color: var(--ivory-dim);
  border-bottom: 1px solid transparent;
  transition: color 0.16s var(--ease), border-color 0.16s var(--ease);
}

.footer-link:hover { color: var(--gold); border-bottom-color: rgba(201, 162, 39, 0.5); }

.footer-contact__row {
  display: grid;
  gap: 0.1rem;
  padding-block: 0.45rem;
  border-bottom: 1px dashed var(--line);
}

.footer-contact__label {
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.2em;
  color: var(--stone);
}

.footer-contact__value {
  font-size: 0.88rem;
  line-height: 1.65;
  color: var(--ivory);
  word-break: break-word;
}

.footer-meta {
  width: var(--shell);
  margin: clamp(1.75rem, 4vw, 2.75rem) auto 0;
  padding-top: 1rem;
  border-top: 1px solid var(--line);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.7rem 1.5rem;
  font-size: 0.78rem;
  color: var(--stone);
}

.footer-meta__copy {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
}

.footer-meta__legal {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem 1rem;
}

.footer-meta__legal .footer-link { font-size: 0.78rem; }

/* ---------- 16. 显现与工具 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(14px) rotateX(-7deg);
  transform-origin: top center;
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
}

[data-reveal].is-in {
  opacity: 1;
  transform: none;
}

.back-to-top {
  position: fixed;
  right: 1rem;
  bottom: 1rem;
  z-index: 70;
  padding: 0.6rem 0.85rem;
  background: rgba(14, 43, 36, 0.94);
  color: var(--ivory);
  border: 2px solid var(--bamboo);
  border-radius: var(--radius-ui);
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  cursor: pointer;
  box-shadow: var(--shadow-hard);
}

.back-to-top:hover { border-color: var(--gold); color: var(--gold); }

/* ---------- 17. 响应式 ---------- */
@media (max-width: 1080px) {
  :root { --header-h: 150px; }

  .header-inner {
    grid-template-columns: minmax(0, 1fr) auto;
    grid-template-areas:
      "brand toggle"
      "ver ver"
      "nav nav";
    align-items: center;
    row-gap: 0.55rem;
  }

  .brand { grid-area: brand; }
  .version-badge { grid-area: ver; justify-self: start; }
  .nav-toggle { grid-area: toggle; justify-self: end; display: inline-flex; align-items: center; gap: 0.5rem; padding: 0.5rem 0.7rem; color: var(--ivory); border: 2px solid var(--bamboo); border-radius: var(--radius-ui); cursor: pointer; }

  .site-header[data-open] .nav-toggle { border-color: var(--gold); color: var(--gold); }
  .site-header[data-open] .nav-toggle__bars i:nth-child(1) { transform: translateY(6px) rotate(45deg); }
  .site-header[data-open] .nav-toggle__bars i:nth-child(2) { opacity: 0; }
  .site-header[data-open] .nav-toggle__bars i:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

  .header-right {
    grid-area: nav;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0.75rem;
    padding-top: 0.85rem;
    border-top: 1px dashed var(--line-strong);
    max-height: calc(100vh - 10rem);
    overflow-y: auto;
  }

  .site-header[data-open] .header-right { display: flex; }

  .site-nav__list { flex-direction: column; align-items: stretch; gap: 0.1rem; }

  .site-nav__link { display: block; padding: 0.68rem 0.35rem; border-bottom: 1px solid var(--line); }
  .site-nav__link[aria-current="page"] { border-bottom-color: var(--cinnabar); }
  .site-nav__link:hover { border-bottom-color: var(--gold); }

  .header-cta { flex-direction: column; align-items: stretch; gap: 0.5rem; }
  .header-cta .btn { width: 100%; }

  .footer-inner { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
  .footer-brand { grid-column: 1 / -1; }
}

@media (max-width: 1000px) {
  .col-3, .col-4, .col-5, .col-6, .col-7, .col-8, .col-9 { grid-column: span 12; }
  .start-2, .start-7 { grid-column-start: auto; }
  .hand-column { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
  .toc { position: static; }
}

@media (max-width: 720px) {
  :root { --header-h: 158px; }
  .version-badge__note { display: none; }
  .footer-inner { grid-template-columns: minmax(0, 1fr); }
  .footer-nav__list { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-meta { flex-direction: column; align-items: flex-start; }
  .tile-wall { padding-bottom: 0.9rem; }
  .tile-wall__item { flex-basis: min(78vw, 300px); }
  .panel { box-shadow: 4px 4px 0 rgba(0, 0, 0, 0.5); }
}

@media (max-width: 420px) {
  .brand__tile { width: 38px; height: 46px; font-size: 1.15rem; }
  .brand__sub { letter-spacing: 0.24em; }
}

/* ---------- 18. 动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
  [data-reveal] { opacity: 1; transform: none; }
  .scroll-meter__bar { transition: none; }
}

/* ---------- 19. 打印 ---------- */
@media print {
  .site-header, .site-footer, .scroll-meter, .back-to-top { display: none !important; }
  body { background: #fff; color: #000; }
}