@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;500;600;700&family=Righteous&display=swap');

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

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

body {
  margin: 0;
  background: #f7f7f5;
  color: #000;
  font-family: 'Poppins', -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  font-size: 17px;
  line-height: 1.75;
  letter-spacing: .01em;
}

h1, h2, h3 {
  font-family: 'Righteous', 'Poppins', -apple-system, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  font-weight: 400;
  line-height: 1.08;
  letter-spacing: -.015em;
  margin: 0 0 .45em;
}

a { color: #000; text-decoration: none; }
img { max-width: 100%; display: block; }
p { margin: 0 0 1.1em; }

:focus-visible { outline: 2px solid #000; outline-offset: 2px; }

/* ---------- 左侧固定竖排导航 ---------- */

.railhead {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 30;
  display: flex;
  flex-direction: column;
  gap: 16px;
  width: 176px;
  padding: 20px 16px;
  background: #fff;
  border-right: 1px solid #000;
}

.mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 12px;
  border-radius: 12px;
  background: #000;
  color: #fff;
  font-size: 16px;
  line-height: 1.2;
  letter-spacing: .02em;
  text-align: center;
  transition: background .22s ease, color .22s ease;
}

.mark img { width: 36px; height: 36px; object-fit: contain; }
.mark .mark-t { word-break: break-all; }
.mark:hover { background: #fff; color: #000; box-shadow: inset 0 0 0 1px #000; }

.nav { margin-top: 4px; flex: 1 1 auto; }
.nav p {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin: 0;
}

.nav a {
  display: flex;
  align-items: center;
  min-height: 40px;
  padding: 6px 12px;
  border: 1px solid #000;
  border-radius: 999px;
  font-size: 16px;
  line-height: 1.25;
  transition: background .22s ease, color .22s ease, transform .22s ease;
}

.nav a:hover,
.nav a:focus-visible {
  background: #000;
  color: #fff;
  transform: translateX(3px);
}

.search { display: flex; margin-top: auto; }

.search input {
  width: 100%;
  min-height: 40px;
  padding: 8px 14px;
  border: 1px solid #000;
  border-radius: 999px;
  background: rgba(255, 255, 255, .6);
  backdrop-filter: blur(12px);
  font: inherit;
  font-size: 16px;
}

.search input::placeholder { color: rgba(0, 0, 0, .5); }

/* ---------- 主体网格：左侧 aside / 右侧正文 ---------- */

main {
  margin-left: 176px;
  display: grid;
  grid-template-columns: 190px minmax(0, 1fr);
  align-items: start;
}

.rail {
  position: sticky;
  top: 0;
  align-self: start;
  max-height: 100vh;
  overflow: auto;
  padding: 36px 18px;
  background: #fff;
  border-right: 1px solid #000;
}

.rail h2 { font-size: 18px; margin: 0; }

.rail hr {
  border: 0;
  border-top: 1px solid #000;
  margin: 12px 0 16px;
}

.rail ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.rail a {
  display: flex;
  align-items: center;
  min-height: 40px;
  padding: 6px 10px;
  border-radius: 999px;
  font-size: 16px;
  line-height: 1.25;
  transition: background .2s ease, color .2s ease;
}

.rail a:hover,
.rail a.is-active { background: #000; color: #fff; }

.doc {
  width: 100%;
  min-width: 0;
  max-width: 1200px;
  padding: 0 clamp(20px, 4vw, 64px);
}

.doc section {
  padding: clamp(40px, 6vw, 88px) 0;
  border-bottom: 1px solid #000;
  scroll-margin-top: 96px;
}

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

.doc h2 { font-size: clamp(26px, 3.4vw, 42px); }

.doc h3 {
  font-size: clamp(20px, 2.1vw, 26px);
  margin-top: 1.5em;
}

.doc hr {
  border: 0;
  border-top: 1px solid #000;
  width: 88px;
  margin: 14px 0 26px;
}

.doc p { max-width: 66ch; }
.doc ul, .doc ol { padding-left: 1.3em; max-width: 66ch; }
.doc li { margin: 0 0 .5em; }

.doc a {
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 4px;
  transition: text-decoration-thickness .2s ease;
}

.doc a:hover { text-decoration-thickness: 3px; }

.doc blockquote {
  margin: 1.6em 0;
  padding: 22px 24px;
  border: 1px solid rgba(0, 0, 0, .14);
  border-radius: 18px;
  background: rgba(255, 255, 255, .55);
  backdrop-filter: blur(14px);
}

.doc blockquote > :last-child { margin-bottom: 0; }

.doc figure { margin: 1.6em 0; }

.doc figure img { border-radius: 18px; border: 1px solid rgba(0, 0, 0, .14); }

/* ---------- 首屏 ---------- */

.hero {
  position: relative;
  overflow: hidden;
  min-height: 100vh;
  min-height: 100svh;
  display: grid;
  grid-template-columns: 1.05fr .95fr;
  gap: clamp(20px, 4vw, 56px);
  align-items: center;
  border-bottom: 1px solid #000;
}

.hero-mark {
  position: absolute;
  right: -2vw;
  top: 7%;
  z-index: 0;
  font-family: 'Righteous', 'Poppins', sans-serif;
  font-size: clamp(48px, 12vw, 170px);
  line-height: .92;
  letter-spacing: -.03em;
  color: rgba(0, 0, 0, .07);
  white-space: nowrap;
  pointer-events: none;
}

.hero > * { position: relative; z-index: 1; }

.collage { position: relative; height: min(66vh, 520px); }

.collage figure {
  margin: 0;
  position: absolute;
  overflow: hidden;
  border: 1px solid #000;
  border-radius: 18px;
  background: rgba(255, 255, 255, .5);
  backdrop-filter: blur(14px);
  transition: transform .25s ease;
}

.collage figure:nth-child(1) { left: 0; top: 0; width: 66%; height: 64%; }
.collage figure:nth-child(2) { right: 0; bottom: 0; width: 58%; height: 52%; }
.collage figure:hover { transform: translate3d(0, -6px, 0); }
.collage img { width: 100%; height: 100%; object-fit: cover; }

.shot-empty {
  display: block;
  width: 100%;
  height: 100%;
  background: repeating-linear-gradient(45deg, #fff, #fff 8px, #efefec 8px, #efefec 16px);
}

.hero-copy { text-align: right; justify-self: end; max-width: 520px; }
.hero h1 { font-size: clamp(34px, 5.4vw, 62px); margin: 0 0 20px; }

.lede {
  margin: 0 0 0 auto;
  max-width: 38ch;
  font-size: 17px;
  line-height: 1.72;
  color: rgba(0, 0, 0, .74);
}

/* ---------- 页脚 ---------- */

footer {
  margin-left: 176px;
  display: grid;
  grid-template-columns: 1.3fr 1fr auto;
  align-items: center;
  gap: 20px 32px;
  padding: 24px clamp(20px, 4vw, 64px);
  background: #fff;
  border-top: 1px solid #000;
}

footer section { min-width: 0; }

.foot-brand {
  margin: 0;
  font-family: 'Righteous', 'Poppins', sans-serif;
  font-size: 18px;
  letter-spacing: .01em;
}

.sub { display: flex; gap: 8px; }

.sub input {
  flex: 1 1 auto;
  min-width: 0;
  min-height: 44px;
  padding: 8px 14px;
  border: 1px solid #000;
  border-radius: 999px;
  background: rgba(255, 255, 255, .6);
  font: inherit;
  font-size: 16px;
}

.sub button {
  flex: 0 0 auto;
  min-height: 44px;
  padding: 0 22px;
  border: 1px solid #000;
  border-radius: 999px;
  background: #000;
  color: #fff;
  font: inherit;
  font-size: 16px;
  cursor: pointer;
  transition: background .2s ease, color .2s ease;
}

.sub button:hover { background: #fff; color: #000; }

.copy { margin: 0; font-size: 16px; white-space: nowrap; }

/* ---------- 动效 ---------- */

@media (prefers-reduced-motion: no-preference) {
  .doc > section { animation: rise .55s cubic-bezier(.2, .7, .2, 1) both; }
  .doc > section:nth-child(1) { animation-delay: .02s; }
  .doc > section:nth-child(2) { animation-delay: .07s; }
  .doc > section:nth-child(3) { animation-delay: .12s; }
  .doc > section:nth-child(4) { animation-delay: .17s; }
  .doc > section:nth-child(5) { animation-delay: .22s; }
  .doc > section:nth-child(6) { animation-delay: .27s; }
  .doc > section:nth-child(7) { animation-delay: .32s; }
  .doc > section:nth-child(8) { animation-delay: .37s; }
}

@keyframes rise {
  from { opacity: 0; transform: translateY(14px); }
  to { opacity: 1; transform: none; }
}

/* ---------- 移动端 ---------- */

@media (max-width: 900px) {
  .railhead {
    position: sticky;
    top: 0;
    left: auto;
    bottom: auto;
    width: auto;
    height: auto;
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
    gap: 10px;
    padding: 12px 16px;
    border-right: 0;
    border-bottom: 1px solid #000;
  }

  .mark { min-height: 40px; padding: 0 14px; font-size: 16px; }

  .nav { order: 3; flex: 1 1 100%; margin: 0; }
  .nav p { flex-direction: row; flex-wrap: wrap; gap: 6px; }
  .nav a { min-height: 40px; }
  .nav a:hover { transform: none; }

  .search { order: 2; flex: 1 1 120px; margin-left: auto; max-width: 190px; }

  main {
    margin-left: 0;
    grid-template-columns: minmax(0, 1fr);
  }

  .rail {
    position: static;
    max-height: none;
    display: flex;
    align-items: center;
    gap: 12px;
    overflow-x: auto;
    padding: 10px 16px;
    border-right: 0;
    border-bottom: 1px solid #000;
    scrollbar-width: none;
  }

  .rail::-webkit-scrollbar { display: none; }
  .rail h2 { font-size: 16px; margin: 0; white-space: nowrap; }
  .rail hr { display: none; }
  .rail ul { flex-direction: row; gap: 8px; }
  .rail a { white-space: nowrap; }

  .doc { padding: 0 20px; }
  .doc section { scroll-margin-top: 132px; }

  .hero {
    grid-template-columns: minmax(0, 1fr);
    gap: 22px;
    min-height: auto;
    padding: 28px 0 44px;
  }

  .hero-copy { order: -1; text-align: left; justify-self: stretch; max-width: none; }
  .hero h1 { font-size: clamp(30px, 8vw, 40px); }
  .lede { margin-left: 0; max-width: none; }

  .hero-mark { top: auto; bottom: 10px; right: 0; font-size: clamp(38px, 15vw, 74px); }

  .collage { height: 220px; }

  footer {
    margin-left: 0;
    grid-template-columns: minmax(0, 1fr);
    gap: 14px;
    padding: 20px;
  }

  .copy { white-space: normal; }
}

@media (min-width: 901px) and (max-width: 1120px) {
  .railhead { width: 156px; }
  main { margin-left: 156px; grid-template-columns: 172px minmax(0, 1fr); }
  footer { margin-left: 156px; grid-template-columns: minmax(0, 1fr); gap: 14px; }
}

button[aria-expanded]{min-width:44px;min-height:44px}