@font-face {
  font-family: "Playfair Display Local";
  src: url("assets/fonts/playfair-display-latin.woff2") format("woff2");
  font-style: normal;
  font-weight: 400 900;
  font-display: swap;
}

@font-face {
  font-family: "Noto Serif SC Local";
  src: url("assets/fonts/noto-serif-sc-display-subset.woff2") format("woff2");
  font-style: normal;
  font-weight: 200 900;
  font-display: swap;
}

/* 正文中文：可变字重，子集覆盖全站已用字符（含 ASCII 与常用标点）。
   改动文案后若出现缺字，重新按站内字符集向 Google Fonts 取子集即可。 */
@font-face {
  font-family: "Noto Sans SC Local";
  src: url("assets/fonts/noto-sans-sc-body-subset.woff2") format("woff2");
  font-style: normal;
  font-weight: 100 900;
  font-display: swap;
}

*, *::before, *::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  background: #f4efe6;
}

body {
  margin: 0;
  min-width: 320px;
  color: var(--ink);
  background-color: var(--paper);
  background-image: radial-gradient(circle, var(--paper-dot) 0.7px, transparent 0.85px);
  background-size: 5px 5px;
  font-family:
    Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont,
    "Segoe UI", "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: clip;
}

button,
a {
  color: inherit;
}

a {
  text-decoration: none;
}

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

img,
svg {
  display: block;
}

:root {
  color-scheme: light;
  --paper: #f4efe6;
  --paper-elevated: rgba(244, 239, 230, 0.94);
  --paper-dot: rgba(83, 70, 55, 0.13);
  --ink: #1a1714;
  --muted: #7d756a;
  --hairline: #c9c0b2;
  --hairline-soft: rgba(132, 117, 96, 0.24);
  --accent: #f0652e;
  --accent-soft: rgba(240, 101, 46, 0.12);
  --status-up: #f0652e;
  --status-partial: #b78420;
  --status-down: #b94734;
  --telegram: #229ed9;
  --whatsapp: #25d366;
  --xiaohongshu: #ff2442;
  --focus: #1a1714;
  --content-left: clamp(7.6rem, 7.4vw, 9.3rem);
  --content-right: clamp(4.25rem, 5.6vw, 7rem);
  --header-height: 5.25rem;
  --display-latin: "Playfair Display Local", "Noto Serif SC Local", Georgia, serif;
  --display-cjk: "Noto Serif SC Local", "Songti SC", "SimSun", serif;
  --body-cjk: "Noto Sans SC Local", Inter, "PingFang SC", "Microsoft YaHei", sans-serif;
  --mono: ui-monospace, "SFMono-Regular", Consolas, monospace;
  --ink-soft: #3a342d;
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
}

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

:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 5px;
}

.site-header {
  position: sticky;
  z-index: 100;
  top: 0;
  height: var(--header-height);
  border-bottom: 1px solid var(--hairline);
  background: var(--paper);
}

.site-header__inner {
  height: 100%;
  padding: 0 clamp(2rem, 3.2vw, 4.2rem);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: inline-flex;
  align-items: center;
  min-height: 2.75rem;
}

.brand__name {
  font-family: var(--display-latin);
  font-size: clamp(2.4rem, 2.8vw, 3.5rem);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.02em;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: clamp(1.65rem, 2.6vw, 3.15rem);
  height: 100%;
}

.site-nav__link,
.utility-control {
  position: relative;
  display: inline-flex;
  align-items: center;
  min-height: 2.75rem;
  color: var(--ink);
  font-size: clamp(1rem, 1.3vw, 1.45rem);
  font-weight: 400;
  letter-spacing: 0.04em;
  white-space: nowrap;
}

.site-nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0.1rem;
  height: 2px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 260ms var(--ease-out);
}

.site-nav__link:hover::after,
.site-nav__link:focus-visible::after,
.site-nav__link.is-active::after {
  transform: scaleX(1);
  transform-origin: left;
}

.lang-toggle {
  min-width: 5.3rem;
  justify-content: center;
}

.nav-toggle {
  display: none;
}

.page-section {
  position: relative;
  min-height: 100svh;
  overflow: hidden;
  isolation: isolate;
}

.page-section::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -2;
  background: linear-gradient(90deg, transparent 0 49.94%, var(--hairline-soft) 50%, transparent 50.06%);
  opacity: 0.12;
  pointer-events: none;
}

.rail-set {
  position: absolute;
  z-index: 5;
  top: 2.75rem;
  bottom: 4.4rem;
  left: clamp(2rem, 2.75vw, 3.25rem);
  width: 2rem;
  pointer-events: none;
}

.rail-set span {
  position: absolute;
  top: 0;
  bottom: 0;
  width: 1px;
  background: var(--hairline);
}

.rail-set span:nth-child(1) { left: 0; }
.rail-set span:nth-child(2) { left: 0.72rem; }
.rail-set span:nth-child(3) { left: 1.43rem; }

.rail-set i {
  position: absolute;
  left: -0.65rem;
  bottom: -0.05rem;
  width: 2.7rem;
  height: 1px;
  background: var(--hairline);
}

.rail-set i::after {
  content: "";
  position: absolute;
  left: 1.35rem;
  top: -0.65rem;
  width: 1px;
  height: 1.35rem;
  background: var(--hairline);
}

/* ═══════════ 滚动入场：区块进入视口时，内容逐项上浮 ═══════════ */
/* 用 animation 而不是 transition：目标里的 .feature-link / .social-link 自己带
   transition，改写 transition 会顶掉它们的 hover 过渡；animation 与之互不干扰。
   位移走 translate 属性而不是 transform，才不会抹掉 .accent-stroke 的 skew
   和 .bp__img 贴底居中用的位移。 */
.js-reveal [data-reveal] {
  opacity: 0;
}

.js-reveal [data-reveal].is-revealed {
  animation: reveal-rise var(--reveal-duration, 1.25s) var(--ease-out)
    var(--reveal-delay, 0ms) both;
}

@keyframes reveal-rise {
  from {
    opacity: 0;
    translate: 0 var(--reveal-shift, 1.9rem);
  }
  to {
    /* 本身就是半透明的元素（水印头像）用 --reveal-opacity 声明自己的落点 */
    opacity: var(--reveal-opacity, 1);
    translate: none;
  }
}

/* 首屏：幅度和节奏收紧一点，和粒子头像的聚合同时进行 */
.hero-copy [data-reveal] {
  --reveal-shift: 1.25rem;
  --reveal-duration: 0.95s;
}

.hero-section {
  min-height: max(48rem, 100svh);
}

.hero-section > .rail-set {
  bottom: 0;
}

.hero-section > .rail-set i {
  display: none;
}

.hero-layout {
  min-height: inherit;
  padding: clamp(5.5rem, 9vh, 8rem) var(--content-right) clamp(4rem, 7vh, 6rem) var(--content-left);
  display: grid;
  grid-template-columns: minmax(0, 55.5%) minmax(22rem, 44.5%);
  align-items: center;
}

.hero-copy {
  position: relative;
  z-index: 3;
  max-width: 46rem;
}

.hero-title {
  margin: 0;
  font-family: var(--display-latin);
  font-size: clamp(7rem, 10.6vw, 11.2rem);
  font-weight: 500;
  line-height: 0.78;
  letter-spacing: -0.025em;
  white-space: nowrap;
}

.hero-role {
  margin: 1.55rem 0 0;
  color: var(--accent);
  font-size: clamp(1.7rem, 2.4vw, 2.55rem);
  font-weight: 420;
  line-height: 1.1;
  letter-spacing: 0.025em;
}

.accent-stroke {
  display: block;
  width: 4.15rem;
  height: 3px;
  margin-top: 1.45rem;
  background: var(--accent);
  transform: skewX(-18deg);
}

/* 卡片组收窄到 36rem（对齐 sac-ai 的 .hero__cta width:min(100%,390px) 收束做法），
   标题横铺、入口聚成一小块，是这套版式里“按钮小一号”的主要来源。
   42vw 那一档管中等宽度：卡片底透明后头像会从卡片里透出来，这里让卡片组停在头像左缘之前 */
.feature-grid {
  margin-top: 2.5rem;
  max-width: min(36rem, 42vw);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.95rem 1.5rem;
}

/* 尺寸/描边/填充照 sac-ai 的 .btn--link：58px 高、16px 字、1px 墨线、底完全透明，
   纸面网点从卡片内部透上来，卡片和背景连成一片而不是浮在上面的色块 */
.feature-link {
  min-height: 3.6rem;
  display: grid;
  grid-template-columns: 1.6rem 1fr 1.1rem;
  align-items: center;
  gap: 0.85rem;
  padding: 0 1.05rem;
  border: 1px solid var(--ink);
  font-size: clamp(1rem, 1.15vw, 1.1rem);
  letter-spacing: 0.02em;
  background: transparent;
  transition:
    color 220ms ease,
    border-color 220ms ease,
    transform 300ms var(--ease-out);
}

/* hover 只换线和字的颜色，不铺底色，免得又把网点盖住 */
.feature-link:hover,
.feature-link:focus-visible {
  color: var(--accent);
  border-color: var(--accent);
  transform: translateY(-2px);
}

.feature-link__icon {
  width: 1.55rem;
  height: 1.55rem;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.5;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.arrow-icon {
  width: 1.1rem;
  height: 1.1rem;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.45;
  stroke-linecap: round;
  stroke-linejoin: round;
  justify-self: end;
  transition: transform 260ms var(--ease-out);
}

.feature-link:hover .arrow-icon,
.feature-link:focus-visible .arrow-icon {
  transform: translateX(0.28rem);
}

.feature-link--wide {
  grid-column: 1 / -1;
  grid-template-columns: 1.6rem minmax(6.5rem, 1fr) auto 0.6rem;
}

.status-text {
  color: var(--accent);
  font-size: 0.88rem;
  letter-spacing: 0.02em;
}

.status-dot {
  width: 0.42rem;
  height: 0.42rem;
  border-radius: 50%;
  background: var(--hairline);
}

.status-dot[data-status="up"] { background: var(--status-up); }
.status-dot[data-status="partial"] { background: var(--status-partial); }
.status-dot[data-status="down"] { background: var(--status-down); }

.hero-portrait {
  position: relative;
  z-index: 1;
  align-self: stretch;
  margin: 0;
  min-width: 0;
}

.hero-portrait::before {
  content: "";
  position: absolute;
  inset: 7% -7% 2% 2%;
  z-index: -1;
  border-radius: 50%;
  background: radial-gradient(circle, color-mix(in srgb, var(--paper) 50%, transparent), transparent 70%);
}

.hero-portrait img {
  position: absolute;
  z-index: 1;
  width: min(49vw, 51rem);
  max-width: none;
  height: auto;
  right: -8rem;
  bottom: -0.8rem;
  opacity: 0.58;
  transition: opacity 320ms var(--ease-out);
  -webkit-mask-image: linear-gradient(to bottom, #000 0 91%, transparent 100%);
  mask-image: linear-gradient(to bottom, #000 0 91%, transparent 100%);
}

/* 粒子层：JS 设定 left/top/width/height（向左扩展）；底部淡出并入粒子透明度 */
.hero-portrait__particles {
  position: absolute;
  z-index: 2;
  display: block;
  max-width: none;
  pointer-events: none;
}

/* 入场期间原图隐藏，由粒子聚合成形；成形后再低透明叠回补足体积 */
.hero-portrait.is-particle-ready img {
  opacity: 0;
}

.hero-portrait.is-particle-ready.is-base-visible img {
  opacity: 0.38;
  filter: saturate(1.16) contrast(1.14) brightness(0.98);
}

.hero-portrait.is-particle-ready.is-base-visible.is-particle-hover img {
  opacity: 0.26;
}

.about-social-section {
  min-height: max(52rem, 100svh);
}

.about-social-section > .rail-set {
  top: 0;
  bottom: 0;
}

.about-social-section > .rail-set i {
  display: none;
}

/* 底部留出 5.8rem：正好是 .about-footer-line 那条线占的高度（bottom 2.4 + 3.4），
   窗口变矮、内容撑高时这条线才不会压进内容里 */
.about-social-layout {
  min-height: calc(100svh - 5.8rem);
  padding: clamp(5.8rem, 11.2vh, 7.8rem) var(--content-right) 5.8rem calc(var(--content-left) + 1.5rem);
  display: grid;
  grid-template-columns: minmax(0, 51%) minmax(0, 49%);
}

.about-panel,
.social-panel {
  position: relative;
  min-width: 0;
}

.about-panel {
  padding-right: clamp(2.4rem, 4vw, 4.5rem);
}

.social-panel {
  padding-left: clamp(2.8rem, 3.5vw, 4.3rem);
  border-left: 1px solid var(--hairline);
}

.section-index {
  margin: 0 0 1.3rem;
  color: var(--accent);
  font-size: 0.86rem;
  font-weight: 600;
  letter-spacing: 0.095em;
}

.section-index b {
  margin: 0 0.75rem;
  color: var(--muted);
  font-weight: 400;
}

.section-index em {
  color: var(--muted);
  font-style: normal;
  font-weight: 500;
}

.display-title {
  margin: 0;
  font-family: var(--display-latin);
  font-size: clamp(5rem, 6.2vw, 6.8rem);
  font-weight: 500;
  line-height: 0.86;
  letter-spacing: -0.025em;
}

.display-title--cjk {
  font-family: var(--display-cjk);
  font-size: clamp(4.4rem, 5.4vw, 6rem);
  font-weight: 550;
  letter-spacing: -0.075em;
  line-height: 0.93;
  margin-top: 0.8rem;
}

.about-copy {
  position: relative;
  z-index: 2;
  margin-top: 2.35rem;
}

.about-copy p {
  margin: 0 0 0.75rem;
  max-width: 31em;
  color: var(--ink-soft);
  font-family: var(--body-cjk);
  font-size: clamp(1rem, 1.35vw, 1.375rem);
  font-weight: 300;
  line-height: 1.65;
}

/* ═══════════ 工程蓝图档案：线稿头像 + 标注 ═══════════ */
/* 下限 19.5rem 是硬约束：再矮，左右两列标注（32% / 60% 与贴底的两块）会互相压上。 */
.blueprint {
  position: relative;
  width: 100%;
  /* 再按视口高度收一道：窗口矮的时候（1080p 满屏≈950px）整段要压进一屏，
     svh 项负责让蓝图跟着变矮，19.5rem 的下限仍然兜住标注不打架 */
  height: clamp(19.5rem, min(23vw, 29.9svh), 21.4rem);
  /* 底部留一点：内容撑高时框底那条边不会和 .about-footer-line 的上边线贴成双线 */
  margin: clamp(2.4rem, min(4vw, 5.03svh), 3.6rem) 0 1.5rem;
  border: 1px solid var(--hairline);
  background-image:
    linear-gradient(color-mix(in srgb, var(--hairline) 14%, transparent) 1px, transparent 1px),
    linear-gradient(90deg, color-mix(in srgb, var(--hairline) 14%, transparent) 1px, transparent 1px);
  background-size: 100% 1.94rem, 1.94rem 100%;
}

/* 居中偏下；bottom 抬起一条 .bp__coords 的高度，坐标行才不会压在卫衣上。
   先按高度定尺寸，窄框再由 max-width 收住，免得压到两侧标注 */
.blueprint .bp__img {
  position: absolute;
  bottom: 1.9rem;
  left: 50%;
  /* 线稿本身重心偏左（头部约 -3%），所以位移比参考站的 -47% 再收一点，
     让人物在框里和 .bp__ring 的圆心对齐 */
  transform: translateX(-42%);
  width: auto;
  height: 78%;
  max-width: 42%;
  object-fit: contain;
  object-position: bottom center;
  mix-blend-mode: multiply;
  filter: saturate(0) contrast(1.05);
}

.bp__ring {
  position: absolute;
  top: 50%;
  left: 53%;
  width: 44%;
  aspect-ratio: 1;
  transform: translate(-50%, -50%);
  border: 1px solid color-mix(in srgb, var(--accent) 16%, transparent);
  border-radius: 50%;
}

/* 四角准星 */
.bp__target {
  position: absolute;
  width: 1.06rem;
  height: 1.06rem;
  border: 1px solid var(--accent);
  border-radius: 50%;
}

.bp__target::before,
.bp__target::after {
  content: "";
  position: absolute;
  background: var(--accent);
}

.bp__target::before {
  top: 50%;
  left: -5px;
  right: -5px;
  height: 1px;
  transform: translateY(-50%);
}

.bp__target::after {
  left: 50%;
  top: -5px;
  bottom: -5px;
  width: 1px;
  transform: translateX(-50%);
}

.bp__target--tl { top: 0.875rem; left: 0.875rem; }
.bp__target--tr { top: 0.875rem; right: 0.875rem; }
.bp__target--bl { bottom: 0.875rem; left: 0.875rem; }
.bp__target--br { bottom: 0.875rem; right: 0.875rem; }

/* 散落十字标记 */
.bp__plus {
  position: absolute;
  transform: translate(-50%, -50%);
  color: var(--hairline);
  font-family: var(--mono);
  font-size: 0.75rem;
  pointer-events: none;
}

.bp__anno {
  position: absolute;
}

.bp__mono {
  margin: 0;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.475rem;
  line-height: 1.62;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  white-space: nowrap;
}

.bp__mono--key {
  color: var(--ink-soft);
  font-weight: 600;
}

.bp__mono--mt {
  margin-top: 0.56rem;
}

.bp__lead {
  margin: 0;
  display: flex;
  align-items: center;
  gap: 0.44rem;
  color: var(--ink);
  font-family: var(--mono);
  font-size: 0.53rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  white-space: nowrap;
}

.bp__sq {
  width: 5px;
  height: 5px;
  display: inline-block;
  background: var(--accent);
}

.bp__hr {
  display: block;
  width: 6.9rem;
  height: 1px;
  margin: 0.44rem 0;
  background: var(--hairline);
}

.bp__hatch {
  display: block;
  width: 2.6rem;
  height: 0.75rem;
  margin-top: 0.375rem;
  background: repeating-linear-gradient(45deg, var(--hairline) 0 1px, transparent 1px 4px);
}

.bp__anno--tl { top: 1.75rem; left: 2.125rem; }
.bp__anno--spec { top: 32%; left: 2.125rem; }
.bp__anno--ver { bottom: 3.6rem; left: 2.125rem; }
.bp__anno--tr { top: 1.75rem; right: 2.125rem; text-align: right; }
.bp__anno--cat { top: 32%; right: 2.125rem; text-align: right; }
.bp__anno--focus { top: 60%; right: 2.125rem; text-align: right; }
.bp__anno--est { bottom: 3.6rem; right: 2.125rem; text-align: right; }

.bp__anno--cat .bp__hatch {
  margin-left: auto;
}

.bp__coords {
  position: absolute;
  left: 50%;
  bottom: 1rem;
  transform: translateX(-50%);
  color: var(--ink-soft);
  font-family: var(--mono);
  font-size: 0.5rem;
  line-height: 1.55;
  letter-spacing: 0.12em;
  white-space: nowrap;
}

/* 蓝图框的响应式集中在这里：框一窄，两侧标注和中间线稿就会互相压上，
   所以每档都成对地调「内缩」和「线稿最大宽度」，而不是只动其中一个。 */
@media (max-width: 1180px) {
  /* 内缩不能小于 2rem：再小会压到四角准星（准星外沿距边 31px） */
  .bp__anno--tl,
  .bp__anno--spec,
  .bp__anno--ver { left: 2rem; }

  .bp__anno--tr,
  .bp__anno--cat,
  .bp__anno--focus,
  .bp__anno--est { right: 2rem; }

  .blueprint .bp__img {
    max-width: 36%;
  }
}

/* 左栏已经窄到放不下五行规格表，只留身份签、档案号和版本块 */
@media (max-width: 1040px) {
  .bp__anno--spec,
  .bp__anno--focus {
    display: none;
  }

  .blueprint .bp__img {
    max-width: 44%;
  }
}

/* 单栏后框子占满宽度，改用比例定高，别再被视口高度压扁 */
@media (max-width: 860px) {
  .blueprint {
    height: auto;
    aspect-ratio: 1.42 / 1;
    margin-top: 2.4rem;
  }

  .blueprint .bp__img {
    max-width: 46%;
  }
}

@media (max-width: 620px) {
  .blueprint {
    aspect-ratio: 1.16 / 1;
  }

  .bp__anno--tl,
  .bp__anno--ver { left: 1.25rem; }

  .bp__anno--tr,
  .bp__anno--cat,
  .bp__anno--est { right: 1.25rem; }

  .blueprint .bp__img {
    max-width: 56%;
  }

  .bp__anno--cat .bp__hatch {
    display: none;
  }
}

.social-heading {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: end;
  gap: 1rem;
}

.social-kicker {
  margin-bottom: 0.2rem;
  color: var(--muted);
  font-family: ui-monospace, "SFMono-Regular", Consolas, monospace;
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  white-space: nowrap;
}

.social-list {
  margin-top: clamp(1.5rem, 3.15svh, 2.25rem);
  border-top: 1px solid var(--hairline);
}

/* 六条链接要和左栏一起收进一屏：行高／图标／首列都挂在 svh 上，
   视口高 ≥ 约 1140px（2560×1440 满屏）时取满上限，等于原来的固定值；
   1080p 满屏（≈950px）时整体等比收一档，不会挤出第二屏 */
.social-link {
  min-height: clamp(4.9rem, 8.55svh, 6.1rem);
  display: grid;
  grid-template-columns: clamp(3.5rem, 5.73svh, 4.1rem) minmax(0, 1fr) 2.1rem;
  align-items: center;
  gap: 1.25rem;
  border-bottom: 1px solid var(--hairline);
  transition:
    color 200ms ease,
    padding-left 320ms var(--ease-out),
    background-color 200ms ease;
}

a.social-link:hover,
a.social-link:focus-visible {
  color: var(--accent);
  padding-left: 0.65rem;
  background: linear-gradient(90deg, var(--accent-soft), transparent 70%);
}

.social-link.is-pending {
  cursor: default;
}

.social-icon {
  width: clamp(3.3rem, 5.45svh, 3.9rem);
  height: clamp(3.3rem, 5.45svh, 3.9rem);
  display: grid;
  place-items: center;
  flex: none;
}

.social-icon svg {
  width: 68%;
  height: 68%;
}

.social-icon--x {
  color: var(--ink);
}

.social-icon--x svg {
  width: 78%;
  height: 78%;
  fill: currentColor;
}

.social-icon--telegram,
.social-icon--whatsapp,
.social-icon--xiaohongshu,
.social-icon--email {
  border-radius: 0.82rem;
  color: #fff;
}

.social-icon--telegram { background: var(--telegram); }
.social-icon--whatsapp { background: var(--whatsapp); }
.social-icon--xiaohongshu { background: var(--xiaohongshu); }
.social-icon--email { background: var(--accent); }

.social-icon--telegram svg {
  fill: currentColor;
}

.social-icon--whatsapp svg {
  fill: currentColor;
}

.social-icon--xiaohongshu svg {
  width: 82%;
  height: 82%;
  fill: currentColor;
}

.social-icon--email svg {
  fill: none;
  stroke: currentColor;
  stroke-width: 1.9;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* LINUX DO 的标志本身就是一枚圆形徽标（浅底 + 黑冠 + 橙底），
   所以不套品牌色方块，直接满格铺满图标位，视觉重量与其他方形徽标持平 */
.social-icon--linuxdo {
  border-radius: 50%;
  overflow: hidden;
  /* 标志中段的浅色（#efefef）和纸色背景几乎同明度，不描一圈的话
     圆盘会断成上黑下橙两瓣；用站内既有的发丝线把轮廓收住 */
  box-shadow: inset 0 0 0 1px var(--hairline-soft);
}

.social-icon--linuxdo svg {
  width: 100%;
  height: 100%;
}

.social-link__body {
  min-width: 0;
  display: grid;
  gap: 0.28rem;
}

.social-link__body strong {
  font-family: var(--display-latin);
  font-size: clamp(1.9rem, 2.25vw, 2.55rem);
  font-weight: 500;
  line-height: 1;
  letter-spacing: -0.02em;
}

html[lang="zh-CN"] [data-i18n="social.xiaohongshuName"] {
  font-family: var(--display-cjk);
  font-weight: 550;
  letter-spacing: -0.06em;
}

.social-link__body small {
  color: var(--muted);
  font-size: 0.83rem;
  letter-spacing: 0.035em;
}

.social-link__arrow {
  width: 2.2rem;
  height: 1.65rem;
  fill: none;
  stroke: var(--accent);
  stroke-width: 1.45;
  stroke-linecap: round;
  stroke-linejoin: round;
  transition: transform 260ms var(--ease-out);
}

a.social-link:hover .social-link__arrow,
a.social-link:focus-visible .social-link__arrow {
  transform: translateX(0.35rem);
}

/* 窗口不够高（非满屏的窄窗）时，左栏 ABOUT 那一列会先顶出一屏——蓝图 19.5rem 的
   下限不能再压，就只收留白。满屏的 1440p / 1200p 视口不进这一档，观感与原来一致。 */
@media (min-width: 861px) and (max-height: 1040px) {
  .about-panel .section-index {
    margin-bottom: 1rem;
  }

  .about-panel .accent-stroke {
    margin-top: 1.15rem;
  }

  .about-copy {
    margin-top: 1.65rem;
  }

  .blueprint {
    margin-bottom: 1.1rem;
  }
}

.about-footer-line {
  position: absolute;
  left: calc(var(--content-left) + 1.5rem);
  right: var(--content-right);
  bottom: 2.4rem;
  min-height: 3.4rem;
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  border-top: 1px solid var(--hairline);
  color: var(--accent);
  font-size: 1rem;
  letter-spacing: 0.08em;
}

.about-footer-line span:last-child {
  color: var(--muted);
  font-family: ui-monospace, "SFMono-Regular", Consolas, monospace;
  font-size: 0.73rem;
  letter-spacing: 0.16em;
}

/* ═══════════ GET IN TOUCH：照搬 sac-ai .contact 那一屏的结构与数值 ═══════════ */
/* 站内其它区块都是左railing、左对齐；这一屏是唯一居中的，左右留白按视觉居中配：
   左边多出的部分是让开 .rail-set（最宽约 5.25rem）。
   高度不跟 .page-section 吃满 100svh：sac 那边 .contact 是带页脚的收尾屏，撑满才成立；
   这里它是中段区块，后面还有整屏的 .site-footer，撑满的话 margin:auto 会把多出来的
   空高一半摊到标题上方，about 收尾线和 GET IN TOUCH 之间就空出一大条 */
.talk-section {
  min-height: min(100svh, 44rem);
  display: flex;
  flex-direction: column;
  padding: clamp(3.5rem, 7vh, 5rem) var(--content-right) 0 clamp(5.9rem, 6.2vw, 7.6rem);
}

/* 和 .about-social-section 一样属于竖线链条的中段：两头都顶满，
   收尾的 L 形脚只留给最后的 .site-footer，中间冒出来就把线打断了 */
.talk-section > .rail-set {
  top: 0;
  bottom: 0;
}

.talk-section > .rail-set i {
  display: none;
}

.talk__center {
  margin: auto;
  padding: 4vh 0;
  text-align: center;
}

.talk__kicker {
  margin: 0 0 1.6rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.875rem;
  color: var(--muted);
  font-size: 0.75rem;
  letter-spacing: 0.22em;
}

.talk__kicker .ln {
  width: 2.5rem;
  height: 1px;
  background: var(--hairline);
}

.talk__title {
  position: relative;
  display: inline-block;
  margin: 0;
  font-family: var(--display-latin);
  font-size: clamp(4.5rem, 10vw, 9.4rem);
  font-weight: 500;
  line-height: 1;
  letter-spacing: -0.01em;
}

/* 手绘感的下划线：贴着标题盒子拉满，preserveAspectRatio=none 让曲线随字号一起横向拉伸 */
.talk__underline {
  position: absolute;
  left: 2%;
  bottom: -2px;
  width: 96%;
  height: 0.16em;
  overflow: visible;
  fill: none;
  stroke: var(--accent);
  stroke-width: 3;
  stroke-linecap: round;
}

.talk__sub {
  margin: 1.85rem 0 0;
  color: var(--ink-soft);
  font-family: var(--body-cjk);
  font-size: clamp(1.06rem, 1.6vw, 1.3rem);
}

.talk__marquee {
  overflow: hidden;
  padding: 0.875rem 0;
  border-top: 1px solid var(--hairline);
  border-bottom: 1px solid var(--hairline);
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 8%, #000 92%, transparent);
  mask-image: linear-gradient(90deg, transparent, #000 8%, #000 92%, transparent);
}

.marquee__track {
  display: flex;
  width: max-content;
  animation: marquee 36s linear infinite;
}

/* 跑马灯是中英混排，不能用 --display-cjk：那份 Noto Serif SC 子集只有 101 个码位、
   一个拉丁字母都没有，Web / build in public 会掉进 SimSun。--display-latin 把拉丁交给
   Playfair、中文落到同一份 Noto Serif SC，两边都在站内字体里 */
.marquee__set {
  flex: none;
  white-space: nowrap;
  color: var(--muted);
  font-family: var(--display-latin);
  font-size: 1.125rem;
  letter-spacing: 0.06em;
}

@keyframes marquee {
  to {
    transform: translateX(-50%);
  }
}

/* 底部联系栏：竖发丝线分列，不套大方框 */
.talk__bar {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  border-bottom: 1px solid var(--hairline);
}

.cbar__item {
  min-height: 10rem;
  display: flex;
  align-items: center;
  gap: 0.875rem;
  padding: 2.1rem;
  transition: background-color 250ms ease;
}

.cbar__item + .cbar__item {
  border-left: 1px solid var(--hairline);
}

.cbar__item:hover,
.cbar__item:focus-visible {
  background: color-mix(in srgb, var(--ink) 3%, transparent);
}

.cbar__logo {
  width: 1.375rem;
  height: 1.375rem;
  flex: none;
  color: var(--ink);
}

.cbar__logo svg {
  width: 100%;
  height: 100%;
  fill: currentColor;
}

.cbar__logo--telegram {
  color: var(--telegram);
}

.cbar__logo--stroke svg {
  fill: none;
  stroke: currentColor;
  stroke-width: 1.9;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* flex:1 把箭头顶到最右，同时和图标保持同一行 */
.cbar__val {
  flex: 1;
  min-width: 0;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  font-size: 1.125rem;
}

.cbar__val b {
  font-weight: inherit;
}

.cbar__val em {
  color: var(--muted);
  font-size: 0.82rem;
  font-style: normal;
}

.cbar__lbl {
  flex: none;
  color: var(--muted);
  font-size: 0.69rem;
  letter-spacing: 0.16em;
}

/* 邮箱这一列没有图标，用一条下划线把地址标出来，并让箭头自己靠右 */
.cbar__val--mail {
  flex: none;
  padding-bottom: 3px;
  border-bottom: 1px solid var(--ink);
  transition:
    color 250ms ease,
    border-color 250ms ease;
}

.cbar__item--mail .cbar__arr {
  margin-left: auto;
}

.cbar__item:hover .cbar__val--mail,
.cbar__item:focus-visible .cbar__val--mail {
  color: var(--accent);
  border-color: var(--accent);
}

.cbar__arr {
  width: 1.7rem;
  height: 1.3rem;
  flex: none;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.45;
  stroke-linecap: round;
  stroke-linejoin: round;
  transition:
    transform 250ms var(--ease-out),
    color 250ms ease;
}

.cbar__item:hover .cbar__arr,
.cbar__item:focus-visible .cbar__arr {
  color: var(--accent);
  transform: translateX(0.3rem);
}

.site-footer {
  min-height: max(43rem, 100svh);
}

.site-footer > .rail-set {
  top: 0;
}

.site-footer__inner {
  position: relative;
  min-height: inherit;
  padding: clamp(10.5rem, 23vh, 14rem) var(--content-right) 0 var(--content-left);
}

.site-footer__inner::before {
  content: "";
  position: absolute;
  top: clamp(9rem, 20vh, 12rem);
  left: calc(var(--content-left) + 1.25rem);
  right: var(--content-right);
  height: 1px;
  background: var(--hairline);
}

.footer-meta {
  position: relative;
  z-index: 3;
  display: flex;
  align-items: center;
  gap: 3.5rem;
  padding-top: 3.5rem;
  padding-left: 1.25rem;
}

.footer-meta small {
  font-size: clamp(1rem, 1.3vw, 1.22rem);
  font-style: normal;
}

.footer-meta a {
  text-decoration: underline;
  text-decoration-color: var(--accent);
  text-underline-offset: 0.42rem;
  text-decoration-thickness: 1px;
}

.footer-wordmark {
  position: absolute;
  z-index: 1;
  left: clamp(5.5rem, 6.7vw, 7.1rem);
  bottom: 1rem;
  color: color-mix(in srgb, var(--hairline) 78%, transparent);
  font-family: var(--display-latin);
  font-size: clamp(11rem, 20vw, 23rem);
  font-weight: 500;
  line-height: 0.76;
  letter-spacing: -0.025em;
  white-space: nowrap;
}

.footer-portrait {
  position: absolute;
  z-index: 2;
  width: min(38vw, 38rem);
  height: auto;
  right: -15rem;
  bottom: 2.3rem;
  opacity: 0.55;
  --reveal-opacity: 0.55;
  -webkit-mask-image: linear-gradient(to bottom, #000 0 88%, transparent 100%);
  mask-image: linear-gradient(to bottom, #000 0 88%, transparent 100%);
}

@media (max-width: 1180px) {
  :root {
    --content-left: clamp(5.5rem, 8.2vw, 7rem);
    --content-right: clamp(2.3rem, 4vw, 4rem);
  }

  .hero-layout {
    grid-template-columns: minmax(0, 58%) minmax(17rem, 42%);
  }

  .hero-title {
    font-size: clamp(6.25rem, 10.5vw, 8.6rem);
  }

  .feature-grid {
    gap: 0.85rem 1.2rem;
  }

  .hero-portrait img {
    width: min(49vw, 39rem);
    right: -4rem;
  }

  .about-social-layout {
    grid-template-columns: minmax(0, 46%) minmax(0, 54%);
  }

  .display-title {
    font-size: clamp(4.6rem, 7.1vw, 6.3rem);
  }

  .display-title--cjk {
    font-size: clamp(4rem, 6.15vw, 5.5rem);
  }

  .social-link {
    min-height: clamp(4.55rem, 7.78svh, 5.55rem);
    grid-template-columns: clamp(3.3rem, 5.4svh, 3.85rem) minmax(0, 1fr) 1.85rem;
    gap: 1.05rem;
  }

  .social-icon {
    width: clamp(3.1rem, 5.12svh, 3.65rem);
    height: clamp(3.1rem, 5.12svh, 3.65rem);
  }
}

@media (max-width: 860px) {
  :root {
    --header-height: 4.4rem;
    --content-left: 1.5rem;
    --content-right: 1.5rem;
  }

  .site-header__inner {
    padding: 0 1.25rem;
  }

  .brand__name {
    font-size: 2.35rem;
  }

  .nav-toggle {
    position: relative;
    z-index: 3;
    width: 2.75rem;
    height: 2.75rem;
    display: grid;
    place-content: center;
    gap: 0.38rem;
  }

  .nav-toggle span {
    display: block;
    width: 1.55rem;
    height: 1px;
    background: currentColor;
    transition: transform 240ms var(--ease-out);
  }

  .nav-toggle[aria-expanded="true"] span:first-child {
    transform: translateY(0.2rem) rotate(45deg);
  }

  .nav-toggle[aria-expanded="true"] span:last-child {
    transform: translateY(-0.2rem) rotate(-45deg);
  }

  .site-nav {
    position: absolute;
    z-index: 2;
    top: 100%;
    left: 0;
    right: 0;
    height: auto;
    padding: 1.2rem 1.5rem 1.5rem;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.6rem 1rem;
    border-bottom: 1px solid var(--hairline);
    background: var(--paper-elevated);
    transform: translateY(-1rem);
    opacity: 0;
    visibility: hidden;
    transition:
      transform 250ms var(--ease-out),
      opacity 180ms ease,
      visibility 180ms ease;
  }

  .site-nav.is-open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .site-nav__link,
  .utility-control {
    min-height: 2.9rem;
    justify-content: center;
    font-size: 0.95rem;
  }

  /* 三个链接占满第一行，语言切换独占第二行，不然会孤零零地缩在左下角 */
  .lang-toggle {
    min-width: 0;
    grid-column: 1 / -1;
  }

  .page-section::before {
    display: none;
  }

  .rail-set {
    left: 0.72rem;
    width: 1px;
  }

  .rail-set span {
    display: none;
  }

  .rail-set span:first-child {
    display: block;
    left: 0;
  }

  .rail-set i {
    left: -0.38rem;
    width: 1.2rem;
  }

  .rail-set i::after {
    left: 0.6rem;
  }

  .hero-section {
    min-height: auto;
  }

  .hero-layout {
    min-height: 0;
    padding: 5.2rem var(--content-right) 5rem var(--content-left);
    display: grid;
    grid-template-columns: 1fr;
    align-items: start;
  }

  .hero-copy {
    display: contents;
  }

  .hero-title {
    order: 1;
    font-size: clamp(4.2rem, 20vw, 7.4rem);
    line-height: 0.82;
    white-space: normal;
  }

  .hero-role {
    order: 2;
    margin-top: 1.2rem;
    font-size: clamp(1.35rem, 6.4vw, 2rem);
  }

  .hero-copy > .accent-stroke {
    order: 3;
    margin-top: 1rem;
  }

  /* 头像图比盒子高，会往外溢出；压到文字和卡片下面去，别盖住它们 */
  .hero-portrait {
    order: 4;
    z-index: -1;
    width: calc(100% + 2rem);
    height: clamp(18rem, 93vw, 32rem);
    margin: 2.5rem 0 0 -1rem;
  }

  .hero-portrait img {
    width: min(118vw, 35rem);
    right: 50%;
    bottom: -3.5rem;
    transform: translateX(50%);
    opacity: 0.58;
  }

  .hero-portrait.is-particle-ready.is-base-visible img {
    opacity: 0.44;
  }

  .hero-portrait.is-particle-ready.is-base-visible.is-particle-hover img {
    opacity: 0.36;
  }

  /* 头像 img 用 bottom:-3.5rem 出血，比 figure 盒子低 3.5rem；
     这里的上边距必须大于那个出血量，第一张卡才不会被头像压住 */
  .feature-grid {
    order: 5;
    width: 100%;
    max-width: none;
    margin-top: 4.5rem;
    grid-template-columns: 1fr;
    gap: 0.7rem;
  }

  .feature-link,
  .feature-link--wide {
    grid-column: auto;
    min-height: 3.35rem;
    grid-template-columns: 1.5rem 1fr 1.05rem;
    padding: 0 0.9rem;
    font-size: 0.98rem;
  }

  .feature-link--wide {
    grid-template-columns: 1.5rem minmax(5.5rem, 1fr) auto 0.5rem;
  }

  .status-text {
    font-size: 0.78rem;
  }

  .about-social-section {
    min-height: auto;
  }

  .about-social-layout {
    min-height: 0;
    padding: 5rem var(--content-right) 7.3rem var(--content-left);
    grid-template-columns: 1fr;
    gap: 5.2rem;
  }

  /* 蓝图档案回到文档流里，不再需要为绝对定位的头像预留高度 */
  .about-panel {
    min-height: 0;
    padding-right: 0;
  }

  .social-panel {
    padding-left: 0;
    border-left: 0;
  }

  .section-index {
    margin-bottom: 1.1rem;
  }

  .display-title,
  .display-title--cjk {
    font-size: clamp(4.4rem, 20vw, 6.6rem);
  }

  .about-copy {
    margin-top: 2rem;
  }

  .about-copy p {
    font-size: 1rem;
    line-height: 1.7;
  }

  .social-heading {
    display: block;
  }

  .social-kicker {
    display: block;
    margin-top: 1.25rem;
  }

  .social-list {
    margin-top: 1.35rem;
  }

  .social-link {
    min-height: 5.25rem;
    grid-template-columns: 3.55rem minmax(0, 1fr) 1.6rem;
    gap: 0.85rem;
  }

  .social-icon {
    width: 3.35rem;
    height: 3.35rem;
    border-radius: 0.7rem;
  }

  .social-link__body strong {
    font-size: clamp(1.65rem, 7vw, 2rem);
  }

  .social-link__body small {
    font-size: 0.72rem;
  }

  .about-footer-line {
    left: var(--content-left);
    right: var(--content-right);
    bottom: 1.6rem;
    min-height: 2.8rem;
    font-size: 0.78rem;
  }

  .about-footer-line span:last-child {
    font-size: 0.6rem;
  }

  /* 手机上不再强撑满屏：水印比桌面小得多，撑满会在备案号下面空出一大片。
     改成「内容高度 + 一条刚好容得下水印头像的底部带」。 */
  .site-footer {
    min-height: 0;
  }

  /* 手机上字标和头像改成上下错开：头像在上、字标压底，各占一条带。
     桌面那种「头像盖在水印上」的叠压在窄屏会直接吃掉半个名字，这里不复制。 */
  .site-footer__inner {
    --footer-portrait-size: min(58vw, 16rem);
    /* 字标按视口宽度定尺寸：LIXUWEI 七个字母约 4.3em 宽，21vw 收进一屏还留得住右边距 */
    --footer-wordmark-size: min(9rem, 21vw);
    /* 底部字标带 = 字高（line-height .76）+ 上下留白，头像抬到这条带之上 */
    --footer-wordmark-band: calc(var(--footer-wordmark-size) * 0.76 + 2.1rem);
    min-height: 0;
    padding: 7.3rem var(--content-right)
      calc(var(--footer-portrait-size) + var(--footer-wordmark-band)) var(--content-left);
  }

  .site-footer__inner::before {
    top: 6rem;
    left: var(--content-left);
    right: var(--content-right);
  }

  .footer-meta {
    display: grid;
    gap: 1.2rem;
    padding-top: 1.75rem;
    padding-left: 0;
  }

  .footer-meta small {
    font-size: 0.95rem;
  }

  /* bottom 必须是正值：line-height .76 让字形比行盒低出约 0.06em，
     负值会被 .page-section 的 overflow:hidden 削掉字母底边 */
  .footer-wordmark {
    left: 1.2rem;
    bottom: 0.9rem;
    font-size: var(--footer-wordmark-size);
    letter-spacing: -0.025em;
  }

  .footer-portrait {
    width: var(--footer-portrait-size);
    right: -2.6rem;
    bottom: var(--footer-wordmark-band);
    opacity: 0.56;
    --reveal-opacity: 0.56;
  }

  /* 窄屏没有左侧 rail 要让，收回和其它区块一致的边距 */
  .talk-section {
    padding: clamp(3rem, 6vh, 4rem) var(--content-right) 0 var(--content-left);
  }

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

  .cbar__item {
    min-height: auto;
    padding: 1.4rem 0;
  }

  .cbar__item + .cbar__item {
    border-left: 0;
    border-top: 1px solid var(--hairline);
  }

  .cbar__item:hover,
  .cbar__item:focus-visible {
    background: none;
  }
}

@media (max-width: 460px) {
  .talk__center {
    padding: 2.5rem 0;
  }

  .talk__kicker {
    gap: 0.5rem;
    font-size: 0.63rem;
  }

  .talk__kicker .ln {
    width: 1.5rem;
  }

  .talk__title {
    font-size: clamp(3.1rem, 15vw, 3.75rem);
    white-space: nowrap;
  }

  .talk__sub {
    font-size: 0.97rem;
  }

  .marquee__set {
    font-size: 1rem;
  }

  .cbar__val {
    font-size: 0.97rem;
    overflow-wrap: anywhere;
  }

  .site-nav {
    grid-template-columns: repeat(2, 1fr);
  }

  /* 两列下 3 链接 + 语言切换正好铺满两行，不需要再独占一行 */
  .lang-toggle {
    grid-column: auto;
  }

  .hero-layout {
    padding-top: 4.3rem;
  }

  .hero-title {
    font-size: clamp(3.7rem, 19.2vw, 5.3rem);
    letter-spacing: -0.025em;
  }

  .hero-portrait {
    height: 20rem;
  }

  .feature-link--wide {
    grid-template-columns: 1.5rem minmax(4.5rem, 1fr) auto;
  }

  .feature-link--wide .status-dot {
    display: none;
  }

  .about-panel {
    min-height: 0;
  }

  .about-footer-line span:last-child {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  /* 粒子层保留，但 JS 只绘制一帧静态成形画面，不做入场与扰动 */
  .hero-portrait.is-particle-ready.is-base-visible img {
    opacity: 0.42;
  }

  /* 跑马灯停在原位，别被全局的 0.01ms 直接甩到轨道末端 */
  .marquee__track {
    animation: none;
  }

  /* 不做滚动入场，内容一开始就是就位状态 */
  .js-reveal [data-reveal] {
    opacity: 1;
  }

  .js-reveal [data-reveal].is-revealed {
    animation: none;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}