/* ==========================================================================
   捻指 nyenzas · 官网
   版式与动效参考 setaprint.ch：黑色舞台、巨型衬线标题、滚动擦洗宣言、
   20 栏栅格、浅灰大圆角页脚。所有视觉数值集中在本文件 :root token 区。
   ========================================================================== */

@font-face {
  font-family: "Source Serif 4";
  font-style: normal;
  font-weight: 300;
  font-display: swap;
  src: url("/assets/fonts/source-serif-4-300.woff2") format("woff2");
}

@font-face {
  font-family: "Source Serif 4";
  font-style: italic;
  font-weight: 300;
  font-display: swap;
  src: url("/assets/fonts/source-serif-4-300-italic.woff2") format("woff2");
}

:root {
  /* 色彩 */
  --c-black: #000000;
  --c-ink: #000000;
  --c-grey-01: #e7e7e7;
  --c-grey-02: #dfdfdf;
  --c-grey-03: #c4c4c4;
  --c-grey-05: #777777;
  --c-grey-06: #5c5c5c;
  --c-grey-07: #272727;
  --c-white: #ffffff;
  --c-blue: #5b67f0;
  --c-lavender: #a9a6f2;
  --c-pink: #f2c6d8;
  --c-sand: #d8c3a5;

  /* 渐变 */
  --gradient-brand: linear-gradient(100deg, var(--c-blue) 0%, var(--c-lavender) 48%, var(--c-pink) 100%);
  --gradient-text: linear-gradient(92deg, var(--c-blue) 0%, var(--c-lavender) 34%, var(--c-pink) 62%, var(--c-grey-01) 100%);
  --gradient-veil: linear-gradient(to top, var(--c-black) 0%, rgba(0, 0, 0, 0.82) 38%, rgba(0, 0, 0, 0) 100%);

  /* 字体 */
  --font-serif: "Source Serif 4", "Songti SC", "Noto Serif SC", "Source Han Serif SC", "SimSun", serif;
  --font-sans: "Helvetica Neue", Helvetica, "PingFang SC", "Noto Sans SC", "Microsoft YaHei", Arial, sans-serif;
  --font-mono: ui-monospace, "SFMono-Regular", "SF Mono", Menlo, "JetBrains Mono", "Courier New", monospace;

  /* 字号（≥1024 桌面 token；移动端在媒体查询内收窄） */
  --text: 20px;
  --title: 60px;
  --lead: 30px;
  --label: 16px;
  --micro: 12px;
  --hero-size: clamp(46px, 8.2vw, 132px);
  --manifesto-size: clamp(38px, 7vw, 108px);
  --feature-size: clamp(56px, 13vw, 200px);
  --contact-size: clamp(32px, 4.4vw, 76px);

  /* 栅格与间距 */
  --gutter: clamp(20px, 2.5vw, 40px);
  --col-gap: 0.5vw;
  --section-y: clamp(72px, 12vh, 160px);
  --radius-footer: clamp(28px, 2.5vw, 48px);
  --line: 1px solid currentColor;

  /* 动效 */
  --ease-out-expo: cubic-bezier(0.19, 1, 0.22, 1);
  --ease-in-out-quart: cubic-bezier(0.37, 0, 0.63, 1);
  --ease-out-quart: cubic-bezier(0.33, 1, 0.68, 1);
  --dur-fast: 250ms;
  --dur-base: 500ms;
  --dur-slow: 900ms;
  --dur-scene: 1500ms;
}

* {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  background: var(--c-black);
  color: var(--c-grey-01);
  font-family: var(--font-sans);
  font-size: var(--text);
  font-weight: 500;
  line-height: 1.2;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

body.menu-open {
  overflow: hidden;
}

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

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

img {
  display: block;
  max-width: 100%;
}

::selection {
  background: var(--c-lavender);
  color: var(--c-ink);
}

:focus-visible {
  outline: 1px solid currentColor;
  outline-offset: 4px;
}

/* ---------- 通用原子 ---------- */

.mono {
  font-family: var(--font-mono);
  font-size: var(--micro);
  font-weight: 500;
  letter-spacing: 0;
  text-transform: lowercase;
}

.serif {
  font-family: var(--font-serif);
  font-weight: 300;
}

.display {
  font-family: var(--font-serif);
  font-weight: 300;
  letter-spacing: -0.015em;
  line-height: 0.9;
}

.gradient-text {
  color: transparent;
  background: var(--gradient-text);
  -webkit-background-clip: text;
  background-clip: text;
}

/* ---------- 颗粒 / 载入遮罩 / 页面转场 ---------- */

.grain {
  position: fixed;
  inset: 0;
  z-index: 50;
  pointer-events: none;
  opacity: 0.06;
  mix-blend-mode: soft-light;
  background-image: url("data:image/svg+xml;utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='220' height='220'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='220' height='220' filter='url(%23n)' opacity='0.55'/%3E%3C/svg%3E");
}

.load-veil {
  position: fixed;
  inset: 0;
  z-index: 90;
  background: var(--c-black);
  pointer-events: none;
}

.page-veil {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  height: 0;
  z-index: 85;
  background: var(--c-grey-01);
  border-radius: var(--radius-footer) var(--radius-footer) 0 0;
  transition: height var(--dur-scene) var(--ease-out-expo);
}

.page-veil.active {
  height: 105vh;
}

/* ---------- HUD（固定四角界面层） ---------- */

.hud {
  position: fixed;
  inset: 0;
  z-index: 75;
  pointer-events: none;
  color: var(--c-white);
  mix-blend-mode: difference;
  font-family: var(--font-mono);
  font-size: var(--micro);
  line-height: 1.2;
}

.hud > * {
  position: absolute;
}

.hud-brand {
  top: var(--gutter);
  left: 50%;
  transform: translateX(-50%);
  display: block;
  pointer-events: auto;
}

.hud-brand img {
  width: clamp(44px, 4vw, 60px);
  height: auto;
}

.hud-menu {
  top: var(--gutter);
  right: var(--gutter);
  pointer-events: auto;
  padding: 4px 0;
  border-bottom: var(--line);
}

.hud-menu:hover {
  opacity: 0.7;
}

.hud-lang {
  left: var(--gutter);
  bottom: var(--gutter);
}

.hud-date {
  right: var(--gutter);
  bottom: var(--gutter);
}

.corner {
  width: 28px;
  height: 28px;
  opacity: 0.7;
}

.corner::before,
.corner::after {
  content: "";
  position: absolute;
  background: currentColor;
}

.corner::before {
  width: 1px;
  height: 100%;
  left: 50%;
  top: 0;
}

.corner::after {
  height: 1px;
  width: 100%;
  top: 50%;
  left: 0;
}

.corner-tl { top: 8px; left: 8px; }
.corner-tr { top: 8px; right: 8px; }
.corner-bl { bottom: 8px; left: 8px; }
.corner-br { bottom: 8px; right: 8px; }

.hud-lang,
.hud-date,
.corner-bl,
.corner-br {
  opacity: 1;
  transition: opacity var(--dur-base) var(--ease-in-out-quart);
}

.hud-hidden-bottom .hud-lang,
.hud-hidden-bottom .hud-date,
.hud-hidden-bottom .corner-bl,
.hud-hidden-bottom .corner-br {
  opacity: 0;
  transition: opacity var(--dur-base) var(--ease-in-out-quart);
}

/* ---------- 菜单层 ---------- */

.menu-overlay {
  position: fixed;
  inset: 0;
  z-index: 70;
  background: var(--c-black);
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: var(--gutter);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--dur-fast) var(--ease-in-out-quart), visibility var(--dur-fast);
}

.menu-overlay.open {
  opacity: 1;
  visibility: visible;
}

.menu-overlay::after {
  content: "";
  position: absolute;
  right: -10vw;
  bottom: -18vh;
  width: 60vw;
  height: 60vw;
  max-width: 720px;
  max-height: 720px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--c-lavender) 0%, rgba(91, 103, 240, 0.35) 42%, rgba(0, 0, 0, 0) 70%);
  filter: blur(70px);
  opacity: 0.55;
  pointer-events: none;
}

.menu-list {
  position: relative;
  z-index: 1;
  max-width: 900px;
}

.menu-list a {
  display: flex;
  align-items: baseline;
  gap: 24px;
  font-family: var(--font-mono);
  font-size: clamp(22px, 3vw, 30px);
  line-height: 1.9;
  color: var(--c-grey-01);
  opacity: 0;
  transform: translateY(18px);
  transition: opacity var(--dur-base) var(--ease-out-quart), transform var(--dur-base) var(--ease-out-quart), color var(--dur-fast);
}

.menu-list a:hover {
  color: var(--c-lavender);
}

.menu-list a em {
  font-family: var(--font-mono);
  font-style: normal;
  font-size: var(--micro);
  color: var(--c-grey-05);
  min-width: 28px;
}

.menu-overlay.open .menu-list a {
  opacity: 1;
  transform: translateY(0);
}

.menu-overlay.open .menu-list a:nth-child(2) { transition-delay: 40ms; }
.menu-overlay.open .menu-list a:nth-child(3) { transition-delay: 80ms; }
.menu-overlay.open .menu-list a:nth-child(4) { transition-delay: 120ms; }
.menu-overlay.open .menu-list a:nth-child(5) { transition-delay: 160ms; }
.menu-overlay.open .menu-list a:nth-child(6) { transition-delay: 200ms; }
.menu-overlay.open .menu-list a:nth-child(7) { transition-delay: 240ms; }
.menu-overlay.open .menu-list a:nth-child(8) { transition-delay: 280ms; }

.menu-foot {
  position: absolute;
  left: var(--gutter);
  bottom: var(--gutter);
  z-index: 1;
  display: flex;
  gap: 28px;
  color: var(--c-grey-05);
  font-family: var(--font-mono);
  font-size: var(--micro);
}

.menu-foot a:hover {
  color: var(--c-grey-01);
}

/* ---------- 首屏 ---------- */

.hero {
  position: relative;
  height: 100svh;
  min-height: 560px;
  background: var(--c-black);
  overflow: hidden;
}

/* WebGL 不可用时的静态兜底光晕 */
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(48% 52% at 24% 66%, rgba(91, 103, 240, 0.5) 0%, rgba(0, 0, 0, 0) 70%),
    radial-gradient(42% 46% at 52% 44%, rgba(169, 166, 242, 0.38) 0%, rgba(0, 0, 0, 0) 72%),
    radial-gradient(46% 50% at 76% 60%, rgba(242, 198, 216, 0.32) 0%, rgba(0, 0, 0, 0) 72%);
  pointer-events: none;
}

.fluid {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 1;
  will-change: transform;
}

.hero-inner {
  position: relative;
  z-index: 1;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  gap: clamp(16px, 2.4vh, 32px);
  padding: calc(var(--gutter) + 72px) var(--gutter) calc(var(--gutter) + 64px);
}

.hero-eyebrow {
  color: var(--c-grey-03);
}

.hero-title {
  margin: 0;
  font-size: var(--hero-size);
  color: var(--c-grey-01);
  white-space: nowrap;
  perspective: 900px;
}

.hero-title em {
  font-style: italic;
}

.hero-title .word {
  display: inline-block;
  overflow: hidden;
  vertical-align: bottom;
  padding: 0 0.06em 0.08em;
  margin: 0 -0.06em -0.08em;
}

.hero-title .word > span {
  display: inline-block;
  transform-origin: 50% 100%;
}

.hero-slogan {
  margin: clamp(8px, 2vh, 24px) 0 0;
  max-width: 36ch;
  font-family: var(--font-serif);
  font-style: italic;
  font-size: clamp(20px, 2.2vw, 30px);
  line-height: 1.28;
  color: var(--c-grey-01);
}

.hero-slogan-en {
  display: block;
  margin-top: 12px;
  font-family: var(--font-mono);
  font-style: normal;
  font-size: var(--micro);
  letter-spacing: 0.04em;
  color: var(--c-grey-03);
}

.scroll-hint {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  bottom: calc(var(--gutter) + 8px);
  color: var(--c-grey-03);
}

.round-btn {
  position: absolute;
  right: var(--gutter);
  bottom: calc(var(--gutter) + 56px);
  width: clamp(72px, 6vw, 94px);
  height: clamp(72px, 6vw, 94px);
  border: 1px solid var(--c-grey-01);
  border-radius: 50%;
  display: grid;
  place-items: center;
  color: var(--c-grey-01);
  transition: background var(--dur-base) var(--ease-out-quart), color var(--dur-base) var(--ease-out-quart), transform var(--dur-slow) var(--ease-out-expo);
}

.round-btn:hover {
  background: var(--c-grey-01);
  color: var(--c-black);
  transform: rotate(90deg);
}

.round-btn i {
  display: block;
  font-style: normal;
  font-size: 16px;
  letter-spacing: 0.28em;
  line-height: 1;
  writing-mode: vertical-rl;
}

/* ---------- 首屏开场动效 ---------- */

@keyframes introWord {
  from {
    opacity: 0.25;
    transform: translate3d(0, 112%, 0) rotateX(38deg);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

@keyframes introUp {
  from {
    opacity: 0;
    transform: translate3d(0, 24px, 0);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

@keyframes introFade {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes introScale {
  from {
    opacity: 0;
    transform: scale(0.86);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

body.intro-pending .hero-eyebrow,
body.intro-pending .hero-title .word > span,
body.intro-pending .hero-slogan,
body.intro-pending .scroll-hint,
body.intro-pending .round-btn,
body.intro-pending .hud-brand,
body.intro-pending .hud-menu,
body.intro-pending .hud-lang,
body.intro-pending .hud-date,
body.intro-pending .corner {
  opacity: 0;
}

body.intro-play .hero-eyebrow {
  animation: introUp 0.9s var(--ease-out-expo) 0.6s both;
}

body.intro-play .hero-title .word:nth-child(1) > span {
  animation: introWord 1.2s var(--ease-out-expo) 0.8s both;
}

body.intro-play .hero-title .word:nth-child(2) > span {
  animation: introWord 1.2s var(--ease-out-expo) 0.95s both;
}

body.intro-play .hero-title .word:nth-child(3) > span {
  animation: introWord 1.2s var(--ease-out-expo) 1.1s both;
}

body.intro-play .hero-slogan {
  animation: introUp 1s var(--ease-out-expo) 1.4s both;
}

body.intro-play .scroll-hint {
  animation: introFade 0.9s var(--ease-out-expo) 1.75s both;
}

body.intro-play .round-btn {
  animation: introScale 0.9s var(--ease-out-expo) 1.65s both;
}

body.intro-play .hud-brand,
body.intro-play .hud-menu {
  animation: introFade 0.8s var(--ease-out-expo) 1.3s both;
}

body.intro-play .hud-lang,
body.intro-play .hud-date,
body.intro-play .corner {
  animation: introFade 0.9s var(--ease-out-expo) 1.85s both;
}

/* ---------- 宣言（滚动擦洗） ---------- */

.manifesto {
  position: relative;
  height: 700vh;
  background: var(--c-black);
}

.manifesto-sticky {
  position: sticky;
  top: 0;
  height: 100svh;
  overflow: hidden;
  display: flex;
  align-items: center;
}

.manifesto-stage {
  position: relative;
  width: 100%;
  height: 100%;
  display: grid;
  place-items: center;
  padding: 0 var(--gutter);
}

.mline {
  position: absolute;
  left: var(--gutter);
  right: var(--gutter);
  top: 50%;
  margin-top: -0.5em;
  opacity: 0;
  will-change: transform, opacity;
}

.mline-cn {
  display: block;
  font-family: var(--font-serif);
  font-weight: 300;
  font-size: var(--manifesto-size);
  line-height: 1.06;
  letter-spacing: -0.01em;
  color: transparent;
  background: var(--gradient-text);
  -webkit-background-clip: text;
  background-clip: text;
  transform-origin: 50% 50%;
}

.mline-en {
  display: block;
  margin-top: 14px;
  font-family: var(--font-mono);
  font-size: var(--micro);
  color: var(--c-grey-05);
}

.manifesto-progress {
  position: absolute;
  right: var(--gutter);
  bottom: calc(var(--gutter) + 8px);
  color: var(--c-grey-05);
}

/* ---------- 盘式区块 ---------- */

.feature {
  position: relative;
  min-height: 100svh;
  display: flex;
  align-items: flex-end;
  overflow: hidden;
  background: var(--c-black);
  padding: var(--section-y) var(--gutter) calc(var(--gutter) + 24px);
}

.feature-bg {
  position: absolute;
  inset: -10% 0;
  background-position: center;
  background-size: cover;
  opacity: 0.6;
  will-change: transform;
}

.feature-qimen .feature-bg {
  background-image: url("/assets/img/qimen.jpg");
}

.feature-liuren .feature-bg {
  background-image: url("/assets/img/liuren.jpg");
}

.feature-shade {
  position: absolute;
  inset: 0;
  background: var(--gradient-veil);
}

.feature-grid {
  position: relative;
  z-index: 1;
  width: 100%;
  display: grid;
  grid-template-columns: repeat(20, 1fr);
  column-gap: var(--col-gap);
  row-gap: 24px;
  align-items: end;
}

.feature-index {
  grid-column: 1 / span 4;
  align-self: start;
  color: var(--c-grey-03);
}

.feature-title {
  grid-column: 1 / span 9;
  margin: 0;
  font-size: var(--feature-size);
  color: var(--c-grey-01);
}

.feature-copy {
  grid-column: 12 / span 8;
  display: flex;
  flex-direction: column;
  gap: 18px;
  color: var(--c-grey-03);
}

.feature-copy p {
  margin: 0;
  font-size: clamp(16px, 1.3vw, 19px);
  line-height: 1.7;
}

.feature-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.feature-tags span {
  font-family: var(--font-mono);
  font-size: var(--micro);
  color: var(--c-grey-01);
  border: 1px solid var(--c-grey-06);
  border-radius: 999px;
  padding: 7px 14px;
}

/* ---------- 关于 / 本地 ---------- */

.about {
  position: relative;
  background: var(--c-grey-01);
  color: var(--c-ink);
  padding: var(--section-y) var(--gutter);
}

.about-grid {
  display: grid;
  grid-template-columns: repeat(20, 1fr);
  column-gap: var(--col-gap);
  row-gap: clamp(32px, 6vh, 72px);
}

.about-figure {
  grid-column: 1 / span 9;
  position: relative;
  overflow: hidden;
  border-radius: 2px;
  aspect-ratio: 4 / 3;
  background: var(--c-grey-02);
}

.about-figure img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transform: scale(1.04);
  transition: transform var(--dur-scene) var(--ease-out-expo);
}

.about-figure:hover img {
  transform: scale(1);
}

.about-body {
  grid-column: 12 / span 8;
  display: flex;
  flex-direction: column;
  gap: clamp(16px, 2.6vh, 26px);
}

.about-index {
  color: var(--c-grey-06);
}

.about-title {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 300;
  font-size: clamp(38px, 5.4vw, 84px);
  line-height: 1;
  letter-spacing: -0.015em;
}

.about-text {
  margin: 0;
  max-width: 34ch;
  font-size: clamp(16px, 1.3vw, 19px);
  line-height: 1.8;
  color: var(--c-grey-07);
}

.about-stats {
  grid-column: 12 / span 8;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  background: var(--c-grey-03);
  border-top: 1px solid var(--c-grey-03);
}

.stat {
  background: var(--c-grey-01);
  padding: 22px 0 18px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.stat b {
  font-family: var(--font-serif);
  font-weight: 300;
  font-size: clamp(34px, 4vw, 56px);
  line-height: 1;
}

.stat span {
  font-family: var(--font-mono);
  font-size: var(--micro);
  color: var(--c-grey-06);
}

/* ---------- 彩色 logo 收束区 ---------- */

.cta {
  position: relative;
  background: var(--c-black);
  padding: var(--section-y) var(--gutter);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: clamp(24px, 4vh, 48px);
  text-align: center;
  overflow: hidden;
}

.cta::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  width: 70vw;
  height: 70vw;
  max-width: 900px;
  max-height: 900px;
  transform: translate(-50%, -50%);
  border-radius: 50%;
  background: radial-gradient(circle, rgba(169, 166, 242, 0.35) 0%, rgba(91, 103, 240, 0.18) 40%, rgba(0, 0, 0, 0) 70%);
  filter: blur(60px);
  pointer-events: none;
}

.cta-mark {
  position: relative;
  z-index: 1;
  width: clamp(120px, 16vw, 220px);
  height: auto;
}

.cta-title {
  position: relative;
  z-index: 1;
  margin: 0;
  font-family: var(--font-serif);
  font-style: italic;
  font-weight: 300;
  font-size: clamp(26px, 3.4vw, 52px);
  line-height: 1.2;
  color: var(--c-grey-01);
}

.cta-btn {
  position: relative;
  z-index: 1;
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 14px 24px;
  border: 1px solid var(--c-grey-06);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: var(--micro);
  color: var(--c-grey-01);
  transition: border-color var(--dur-base), background var(--dur-base), color var(--dur-base);
}

.cta-btn:hover {
  background: var(--c-grey-01);
  color: var(--c-black);
  border-color: var(--c-grey-01);
}

/* ---------- 页脚 ---------- */

.footer-trench {
  background:
    radial-gradient(120% 80% at 50% 0%, rgba(91, 103, 240, 0.28) 0%, rgba(0, 0, 0, 0) 55%),
    var(--c-black);
  padding: clamp(72px, 18vmin, 200px) 2.5vw 2.5vw;
}

.site-footer {
  background: var(--c-grey-01);
  color: var(--c-ink);
  border-radius: var(--radius-footer);
  padding: clamp(40px, 7vmin, 88px) clamp(24px, 4vmin, 56px) clamp(24px, 3vmin, 40px);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.7fr 1fr 1fr 1fr;
  gap: clamp(24px, 3vw, 48px);
}

.footer-grid--doc {
  grid-template-columns: 1.7fr 1fr 1fr;
}

.footer-col {
  border-left: var(--line);
  padding-left: clamp(14px, 1.6vw, 24px);
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-col:first-child {
  border-left: 0;
  padding-left: 0;
}

.footer-contact-label {
  font-family: var(--font-mono);
  font-size: var(--micro);
  color: var(--c-grey-06);
}

.footer-contact {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 300;
  font-size: var(--contact-size);
  line-height: 0.95;
  letter-spacing: -0.02em;
  word-break: break-word;
}

.footer-contact-sub {
  font-family: var(--font-mono);
  font-size: var(--micro);
  color: var(--c-grey-06);
}

.footer-heading {
  font-family: var(--font-mono);
  font-size: var(--micro);
  color: var(--c-grey-06);
  margin: 0 0 8px;
}

.footer-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  font-size: clamp(14px, 1.1vw, 16px);
  line-height: 1.5;
}

.footer-list a {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  width: fit-content;
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur-fast);
}

.footer-list a:hover {
  border-color: var(--c-ink);
}

.footer-legal-note {
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.6;
  color: var(--c-grey-06);
  max-width: 32ch;
}

.footer-rule {
  height: 1px;
  background: var(--c-grey-03);
  margin: clamp(32px, 5vh, 56px) 0 22px;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px 32px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--c-grey-06);
}

.footer-bottom .filing {
  color: var(--c-grey-06);
}

/* ---------- 文档页（隐私 / 协议 / 清单 / 支持） ---------- */

.doc-page {
  background: var(--c-grey-01);
  color: var(--c-ink);
}

.doc-page .hud {
  color: var(--c-black);
  mix-blend-mode: normal;
}

.doc-page .hud-lang,
.doc-page .hud-date {
  display: none;
}

body.menu-open .hud {
  color: var(--c-white);
  mix-blend-mode: normal;
}

body.menu-open.doc-page .hud-brand img {
  filter: invert(1);
}

.doc-hero {
  padding: clamp(120px, 22vh, 220px) var(--gutter) clamp(40px, 8vh, 90px);
}

.doc-hero .mono {
  color: var(--c-grey-06);
  display: block;
  margin-bottom: 24px;
}

.doc-title {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 300;
  font-size: clamp(42px, 8vw, 128px);
  line-height: 0.98;
  letter-spacing: -0.02em;
}

.doc-updated {
  margin: 24px 0 0;
  font-family: var(--font-mono);
  font-size: var(--micro);
  color: var(--c-grey-06);
}

.doc-body {
  display: grid;
  grid-template-columns: repeat(20, 1fr);
  column-gap: var(--col-gap);
  row-gap: 48px;
  padding: 0 var(--gutter) var(--section-y);
}

.doc-aside {
  grid-column: 1 / span 6;
  align-self: start;
  position: sticky;
  top: 96px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.doc-back {
  font-family: var(--font-mono);
  font-size: var(--micro);
  color: var(--c-grey-06);
  width: fit-content;
  border-bottom: 1px solid var(--c-grey-03);
  padding-bottom: 4px;
}

.doc-back:hover {
  color: var(--c-ink);
  border-color: var(--c-ink);
}

.doc-toc {
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--c-grey-06);
}

.doc-toc a:hover {
  color: var(--c-ink);
}

.doc-note {
  border-top: 1px solid var(--c-grey-03);
  padding-top: 16px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--c-grey-06);
}

.doc-main {
  grid-column: 8 / span 12;
  display: flex;
  flex-direction: column;
  gap: clamp(28px, 4vh, 48px);
}

.doc-section {
  scroll-margin-top: 96px;
}

.doc-section h2 {
  margin: 0 0 12px;
  font-family: var(--font-serif);
  font-weight: 300;
  font-size: clamp(24px, 2.4vw, 34px);
  line-height: 1.2;
}

.doc-section p {
  margin: 0 0 10px;
  font-size: clamp(15px, 1.2vw, 17px);
  line-height: 1.85;
  color: var(--c-grey-07);
}

.doc-section p:last-child {
  margin-bottom: 0;
}

.doc-section strong {
  font-weight: 600;
}

.doc-footer {
  padding: 0 2.5vw 2.5vw;
  background: var(--c-grey-01);
}

/* ---------- 滚动进场（通用） ---------- */

.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity var(--dur-slow) var(--ease-out-quart), transform var(--dur-slow) var(--ease-out-expo);
}

.reveal.in {
  opacity: 1;
  transform: translateY(0);
}

.reveal-clip {
  opacity: 0;
  clip-path: inset(0 0 100% 0);
  transition: opacity var(--dur-slow) var(--ease-out-quart), clip-path var(--dur-scene) var(--ease-out-expo);
}

.reveal-clip.in {
  opacity: 1;
  clip-path: inset(0 0 0 0);
}

/* ---------- 响应式 ---------- */

@media (max-width: 1024px) {
  :root {
    --text: 16px;
    --title: 30px;
    --lead: 20px;
    --label: 12px;
    --micro: 11px;
  }

  .feature-grid,
  .about-grid {
    grid-template-columns: repeat(16, 1fr);
  }

  .feature-title {
    grid-column: 1 / span 9;
  }

  .feature-copy {
    grid-column: 10 / span 7;
  }

  .about-figure {
    grid-column: 1 / -1;
    aspect-ratio: 16 / 11;
  }

  .about-body,
  .about-stats {
    grid-column: 1 / -1;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }

  .footer-grid .footer-col:first-child {
    grid-column: 1 / -1;
  }
}

@media (max-width: 820px) {
  .doc-aside {
    position: static;
    grid-column: 1 / -1;
  }

  .doc-main {
    grid-column: 1 / -1;
  }
}

@media (max-width: 640px) {
  :root {
    --gutter: 20px;
    --section-y: 72px;
    --hero-size: clamp(38px, 10.4vw, 56px);
    --manifesto-size: clamp(30px, 9vw, 44px);
    --feature-size: clamp(56px, 22vw, 104px);
    --contact-size: clamp(34px, 8.6vw, 52px);
    --radius-footer: 28px;
  }

  .corner,
  .hud-date {
    display: none;
  }

  .hud-lang {
    bottom: calc(var(--gutter) + 2px);
  }

  .hero {
    min-height: 520px;
  }

  .hero-inner {
    padding-top: calc(var(--gutter) + 84px);
    padding-bottom: calc(var(--gutter) + 96px);
  }

  .hero-title {
    white-space: normal;
  }

  .hero-title .line-2 {
    display: block;
  }

  .scroll-hint {
    bottom: calc(var(--gutter) + 26px);
  }

  .round-btn {
    width: 64px;
    height: 64px;
  }

  .manifesto {
    height: 520vh;
  }

  .mline {
    margin-top: -0.5em;
  }

  .mline-en {
    margin-top: 10px;
  }

  .feature {
    min-height: 88svh;
    padding-top: 96px;
    padding-bottom: var(--gutter);
  }

  .feature-grid {
    grid-template-columns: 1fr;
    row-gap: 18px;
  }

  .feature-index,
  .feature-title,
  .feature-copy {
    grid-column: 1 / -1;
  }

  .feature-copy {
    max-width: 34ch;
  }

  .about-grid {
    grid-template-columns: 1fr;
  }

  .about-figure {
    aspect-ratio: 4 / 3;
  }

  .footer-trench {
    padding: 72px 12px 12px;
  }

  .site-footer {
    padding: 36px 24px 28px;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .footer-col {
    border-left: 0;
    padding-left: 0;
    border-top: var(--line);
    padding-top: 18px;
  }

  .footer-col:first-child {
    border-top: 0;
    padding-top: 0;
  }

  .menu-foot {
    flex-direction: column;
    gap: 8px;
  }

  .doc-hero {
    padding-top: 132px;
  }
}

@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;
  }

  .reveal,
  .reveal-clip {
    opacity: 1;
    transform: none;
    clip-path: none;
  }
}