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

:root {
  --ink: #000000;
  --paper: #ffffff;
  --mute: #6f6f6f;
  --line: #e4e4e4;
  --wash: #f5f5f5;
  --r: 18px;
  --dock: 72px;
  --sans: "Plus Jakarta Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

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

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

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.72;
  font-weight: 400;
  letter-spacing: .002em;
  overflow-x: hidden;
  padding-bottom: calc(var(--dock) + env(safe-area-inset-bottom, 0px) + 12px);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

[id] { scroll-margin-top: 5rem; }

a { color: var(--ink); }

:focus-visible {
  outline: 2px solid var(--ink);
  outline-offset: 2px;
  border-radius: 4px;
}

.shell {
  width: 100%;
  max-width: 1200px;
  margin-inline: auto;
  padding-inline: 20px;
}

/* ---------- 底部固定导航 ---------- */
.dock {
  position: fixed;
  inset-inline: 0;
  bottom: 0;
  z-index: 60;
  display: flex;
  align-items: center;
  gap: .45rem;
  padding: .55rem 16px calc(.55rem + env(safe-area-inset-bottom, 0px));
  background: rgba(255, 255, 255, .82);
  -webkit-backdrop-filter: blur(18px) saturate(1.15);
  backdrop-filter: blur(18px) saturate(1.15);
  border-top: 1px solid var(--ink);
}

.mark {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  min-height: 44px;
  padding: .4rem .2rem;
  text-decoration: none;
  font-weight: 700;
  letter-spacing: -.02em;
}

.mark-dot {
  width: 10px;
  height: 10px;
  border-radius: 2px;
  background: var(--ink);
  flex: none;
}

.mark-img { border-radius: 4px; display: block; }

.mark-name { font-size: .98rem; white-space: nowrap; }

.dock-toggle {
  margin-inline-start: auto;
  min-height: 44px;
  padding: 0 .9rem;
  font: inherit;
  font-size: .92rem;
  color: var(--ink);
  background: #fff;
  border: 1px solid var(--ink);
  border-radius: 10px;
  cursor: pointer;
  transition: background .2s ease;
}

.dock-toggle:active { background: var(--wash); }

.dock-contact {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 .95rem;
  font-size: .92rem;
  text-decoration: none;
  color: #fff;
  background: var(--ink);
  border-radius: 10px;
}

.dock-menu {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 100%;
  margin: 0;
  padding: .2rem 16px 1rem;
  list-style: none;
  background: rgba(255, 255, 255, .94);
  -webkit-backdrop-filter: blur(18px);
  backdrop-filter: blur(18px);
  border-top: 1px solid var(--line);
  max-height: 62vh;
  overflow-y: auto;
  display: none;
}

.dock.open .dock-menu { display: block; }

.dock-menu > li { border-bottom: 1px solid var(--line); }
.dock-menu > li:last-child { border-bottom: 0; }

.dock-menu > li > a {
  display: flex;
  align-items: center;
  min-height: 48px;
  padding: .55rem .2rem;
  text-decoration: none;
  font-size: 1rem;
  font-weight: 500;
  transition: opacity .2s ease;
}

.dock-menu > li > a:active { opacity: .55; }

.grp {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
}

.grp-btn {
  width: 52px;
  min-height: 48px;
  font: inherit;
  font-size: 1rem;
  color: var(--ink);
  background: none;
  border: 0;
  border-left: 1px solid var(--line);
  cursor: pointer;
}

.panel {
  grid-column: 1 / -1;
  display: none;
  margin: 0 0 .4rem;
  padding: 0 0 0 .85rem;
  list-style: none;
  border-top: 1px dashed var(--line);
}

.grp.open .panel { display: block; }

.panel > li > a {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: .4rem .2rem;
  font-size: .95rem;
  text-decoration: none;
  color: #333;
}

.panel > li > a::before {
  content: "—";
  color: var(--mute);
  margin-inline-end: .55rem;
  font-size: .8rem;
}

/* ---------- 首屏 ---------- */
.hero {
  max-width: 1200px;
  margin-inline: auto;
  padding: 2rem 20px 1.6rem;
  display: grid;
  gap: 1.4rem;
  align-items: center;
}

.hero h1 {
  margin: 0;
  font-size: clamp(2rem, 8vw, 3.6rem);
  line-height: 1.05;
  letter-spacing: -.035em;
  font-weight: 700;
}

.lede {
  margin: .85rem 0 0;
  font-size: 1rem;
  line-height: 1.65;
  color: #3a3a3a;
  max-width: 36ch;
}

.hero-art {
  margin: 0;
  position: relative;
  aspect-ratio: 16 / 11;
  border: 1px solid var(--ink);
  border-radius: var(--r);
  overflow: hidden;
  background-color: var(--wash);
  background-image: radial-gradient(circle at 1px 1px, #000 1px, transparent 0);
  background-size: 14px 14px;
}

.hero-art.has-img {
  background-image: none;
  background-color: var(--wash);
}

.hero-img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

/* ---------- 主体 ---------- */
.board {
  display: grid;
  gap: 1.6rem;
  padding-block: 1.8rem 3rem;
}

.rail {
  background: rgba(255, 255, 255, .62);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  border: 1px solid var(--line);
  border-radius: var(--r);
  padding: 1.05rem 1rem 1.2rem;
}

.eyebrow {
  display: block;
  font-size: .68rem;
  letter-spacing: .22em;
  color: var(--mute);
  font-weight: 500;
}

.eyebrow + .rail-title { margin-top: .3rem; }

.rail-title {
  margin: 0 0 .8rem;
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: -.01em;
}

.rail-list {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: rail;
}

.rail-list > li {
  counter-increment: rail;
  display: flex;
  gap: .5rem;
  align-items: baseline;
  border-top: 1px solid rgba(0, 0, 0, .07);
}

.rail-list > li::before {
  content: counter(rail, decimal-leading-zero);
  font-size: .68rem;
  color: var(--mute);
  letter-spacing: .06em;
  flex: none;
  padding-top: .55rem;
}

.rail-list > li > a {
  flex: 1;
  padding: .45rem 0;
  font-size: .88rem;
  text-decoration: none;
  color: #2b2b2b;
  transition: color .2s ease;
}

.rail-list > li > a:hover { color: #000; text-decoration: underline; text-underline-offset: 3px; }

.body { min-width: 0; overflow-wrap: break-word; counter-reset: sec; }

.body > article {
  counter-increment: sec;
  border-top: 1px solid var(--ink);
  margin-top: 2.8rem;
  padding-top: 1.5rem;
}

.body > article:first-of-type {
  border-top: 0;
  margin-top: 0;
  padding-top: 0;
}

.body > article::before {
  content: counter(sec, decimal-leading-zero);
  display: block;
  font-size: .72rem;
  letter-spacing: .22em;
  color: var(--mute);
  margin-bottom: .55rem;
}

.body h2 {
  margin: 0 0 .8rem;
  font-size: clamp(1.45rem, 4.6vw, 2rem);
  line-height: 1.18;
  letter-spacing: -.025em;
  font-weight: 700;
}

.body h3 {
  margin: 1.7rem 0 .5rem;
  font-size: 1.14rem;
  line-height: 1.35;
  letter-spacing: -.01em;
  font-weight: 600;
}

.body p { margin: 0 0 1.05rem; }

.body ul, .body ol { margin: 0 0 1.15rem; padding-inline-start: 1.2rem; }
.body li { margin: .35rem 0; }

.body a {
  color: var(--ink);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
  transition: opacity .2s ease;
}

.body a:hover { opacity: .6; }

.body figure { margin: 1.5rem 0; }

.body img { max-width: 100%; height: auto; display: block; border-radius: 14px; }

.body blockquote {
  margin: 1.5rem 0;
  padding: .15rem 0 .15rem 1rem;
  border-left: 2px solid var(--ink);
  color: #2f2f2f;
}

.body table {
  width: 100%;
  border-collapse: collapse;
  font-size: .95rem;
  margin: 0 0 1.2rem;
}

.body th, .body td {
  border-bottom: 1px solid var(--line);
  padding: .6rem .5rem;
  text-align: start;
}

.body hr { border: 0; border-top: 1px solid var(--line); margin: 1.8rem 0; }

/* ---------- 联系块 ---------- */
.foot-top {
  margin-top: 1rem;
  padding: 1.5rem 1.2rem;
  display: grid;
  gap: 1.1rem;
  border: 1px solid var(--ink);
  border-radius: var(--r);
  background: rgba(255, 255, 255, .62);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
}

.ft-head small {
  display: block;
  font-size: .68rem;
  letter-spacing: .22em;
  color: var(--mute);
}

.ft-head h2 {
  margin: .25rem 0 0;
  font-size: 1.5rem;
  letter-spacing: -.025em;
  line-height: 1.2;
}

.ft-head h2 a { text-decoration: none; }

.ft-form { display: flex; gap: .5rem; flex-wrap: wrap; }

.ft-form input {
  flex: 1 1 160px;
  min-width: 0;
  min-height: 44px;
  padding: 0 .85rem;
  font: inherit;
  font-size: .95rem;
  color: var(--ink);
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 10px;
}

.ft-form input:focus { border-color: var(--ink); outline: none; }

.ft-form button {
  min-height: 44px;
  padding: 0 1.15rem;
  font: inherit;
  font-size: .95rem;
  color: #fff;
  background: var(--ink);
  border: 1px solid var(--ink);
  border-radius: 10px;
  cursor: pointer;
  transition: opacity .2s ease;
}

.ft-form button:hover { opacity: .78; }

/* ---------- 页脚 ---------- */
.foot {
  display: grid;
  gap: .6rem;
  margin-top: 2.6rem;
  padding: 1.6rem 20px 2rem;
  border-top: 1px solid var(--line);
  font-size: .88rem;
  color: var(--mute);
}

.foot p { margin: 0; }

.foot-brand { font-size: 1rem; font-weight: 700; color: var(--ink); letter-spacing: -.02em; }

.foot-links a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  text-decoration: none;
  color: var(--ink);
  border-bottom: 1px solid var(--ink);
}

.foot-copy { font-size: .8rem; color: var(--mute); }

/* ---------- 动效 ---------- */
@media (prefers-reduced-motion: no-preference) {
  .body > article {
    animation: rise .55s cubic-bezier(.22, .72, .3, 1) both;
  }
  .body > article:nth-of-type(2) { animation-delay: .05s; }
  .body > article:nth-of-type(3) { animation-delay: .1s; }
  .body > article:nth-of-type(4) { animation-delay: .15s; }
  .body > article:nth-of-type(5) { animation-delay: .2s; }
  .body > article:nth-of-type(6) { animation-delay: .25s; }
  .body > article:nth-of-type(7) { animation-delay: .3s; }
  .body > article:nth-of-type(n + 8) { animation-delay: .35s; }
}

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

/* ---------- 平板 ---------- */
@media (min-width: 620px) {
  .hero { padding-top: 2.6rem; }
  .hero-art { aspect-ratio: 16 / 9; }
  .foot { grid-template-columns: 1fr auto auto; align-items: center; gap: 1.6rem; }
  .foot-top { grid-template-columns: 1fr; }
}

/* ---------- 桌面 ---------- */
@media (min-width: 900px) {
  body { font-size: 17px; }

  .dock { gap: .8rem; padding: .5rem 28px; }

  .dock-toggle { display: none; }

  .dock-menu {
    position: static;
    display: flex;
    align-items: center;
    gap: .1rem;
    margin-inline-start: auto;
    padding: 0;
    max-height: none;
    overflow: visible;
    background: none;
    -webkit-backdrop-filter: none;
    backdrop-filter: none;
    border: 0;
  }

  .dock-menu > li { border: 0; }

  .dock-menu > li > a {
    min-height: 44px;
    padding: .55rem .7rem;
    font-size: .93rem;
    border-radius: 9px;
    transition: background .22s ease;
  }

  .dock-menu > li > a:hover { background: var(--wash); opacity: 1; }

  .grp { display: flex; align-items: center; position: relative; }

  .grp-btn {
    width: 26px;
    min-height: 44px;
    border-left: 0;
    font-size: .78rem;
    color: var(--mute);
  }

  .panel {
    position: absolute;
    bottom: calc(100% + 12px);
    left: 0;
    display: block;
    min-width: 200px;
    margin: 0;
    padding: .4rem;
    border: 1px solid var(--ink);
    border-radius: 14px;
    border-top: 1px solid var(--ink);
    background: #fff;
    opacity: 0;
    visibility: hidden;
    transform: translateY(6px);
    transition: opacity .22s ease, transform .22s ease, visibility .22s;
  }

  .grp:hover .panel,
  .grp:focus-within .panel,
  .grp.open .panel {
    opacity: 1;
    visibility: visible;
    transform: none;
  }

  .panel > li > a { border-radius: 9px; padding: .5rem .6rem; }
  .panel > li > a:hover { background: var(--wash); }

  .hero {
    grid-template-columns: 1.05fr .95fr;
    gap: 2.4rem;
    min-height: 45vh;
    padding: 3rem 20px 2rem;
    align-items: center;
  }

  .rail { position: sticky; top: 1.6rem; }

  .board {
    grid-template-columns: 252px minmax(0, 1fr);
    gap: 2.6rem;
    padding-block: 2.4rem 3.6rem;
    align-items: start;
  }

  .foot-top {
    grid-template-columns: 1fr auto;
    align-items: center;
    gap: 2.4rem;
    padding: 1.8rem 2rem;
    margin-top: 1.6rem;
  }

  .ft-form { min-width: 360px; }

  .foot { margin-top: 3rem; padding-inline: 20px; }
}

@media (min-width: 1100px) {
  .hero { padding-inline: 20px; }
  .body { max-width: 74ch; }
}

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