:root {
  color-scheme: light;
  --ground: #f8f6ee;
  --paper: #fffdf6;
  --ink: #30352b;
  --muted: #656858;
  --line: #dedfd1;
  --lime: #bdd779;
  --yellow: #f6e6a6;
  font-family: -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  color: var(--ink);
  background: var(--ground);
  font-synthesis: none;
  line-height: 1.75;
  scroll-behavior: smooth;
  scroll-padding-top: 28px;
}
* { box-sizing: border-box; }
body { margin: 0; }
a { color: inherit; text-underline-offset: 5px; }
button { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
::selection { background: var(--lime); color: var(--ink); }
:focus-visible { outline: 3px solid #526c2e; outline-offset: 5px; }
.wrap { max-width: 1120px; margin-inline: auto; padding-inline: 40px; }
.skip-link { position: absolute; top: -100px; left: 20px; z-index: 5; background: var(--paper); padding: 12px; }
.skip-link:focus { top: 12px; }
.site-header { display: flex; justify-content: space-between; align-items: center; gap: 24px; min-height: 108px; }
.brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; font-size: 20px; font-weight: 750; white-space: nowrap; }
.brand img { flex: none; }
nav { display: flex; gap: 32px; align-items: center; font-size: 14px; }
nav a { text-decoration: none; padding-block: 10px; }
nav a:hover { text-decoration: underline; }
.nav-join { font-weight: 650; }
.nav-join span { margin-left: 8px; }
h1, h2, h3, p { margin: 0; }
h1, h2, h3 { text-wrap: balance; }
.hero { position: relative; display: grid; grid-template-columns: 1.1fr 1fr; column-gap: 36px; padding-top: 55px; }
h1 { font-size: clamp(44px, 5.5vw, 68px); letter-spacing: -.035em; line-height: 1.3; font-weight: 800; }
h1 span { display: inline; background: var(--lime); box-shadow: 9px 0 var(--lime), -3px 0 var(--lime); }
.hero-intro { grid-column: 1; margin-top: 24px; }
.hero-intro > p:first-child { color: var(--muted); font-size: 17px; }
.button { display: inline-flex; justify-content: center; align-items: center; gap: 24px; min-height: 50px; border: 2px solid var(--ink); border-radius: 9px; padding: 10px 22px; background: var(--lime); color: var(--ink); box-shadow: 3px 3px 0 var(--ink); font-size: 15px; font-weight: 650; text-decoration: none; cursor: pointer; transition: transform 150ms ease-out, box-shadow 150ms ease-out, background-color 150ms ease-out; }
.button:hover { background: #adc66a; }
.button:active { transform: translate(2px, 2px); box-shadow: 1px 1px 0 var(--ink); }
.hero-intro .button { margin-top: 28px; }
.entry-note { margin-top: 12px; color: var(--muted); font-size: 12px; }
.conversation { grid-column: 2; grid-row: 1 / 3; align-self: center; padding: 10px 0 0 8px; }
.conversation-title { font-size: 14px; margin: 0 0 24px 8px; display: flex; gap: 9px; align-items: center; }
.live-dot { width: 8px; height: 8px; background: #526c2e; border-radius: 50%; }
.bubble { position: relative; border: 2px solid var(--ink); border-radius: 14px; padding: 19px 22px; background: var(--paper); box-shadow: 4px 4px 0 var(--ink); font-weight: 600; font-size: 19px; line-height: 1.7; }
.bubble-question { max-width: 360px; transform: rotate(-3deg); }
.bubble-reply { margin: 22px 0 0 auto; max-width: 258px; background: var(--yellow); transform: rotate(3deg); }
.bubble-small { margin: 27px 20px 0 12px; font-size: 15px; font-weight: 500; box-shadow: 3px 3px 0 var(--ink); }
.example-note { display: block; text-align: right; margin-top: 13px; font-size: 11px; color: var(--muted); }
.campus { grid-column: 1 / -1; position: relative; height: 236px; margin-top: 64px; overflow: hidden; border: 2px solid var(--ink); border-radius: 14px; }
.campus img { display: block; width: 100%; height: 100%; object-fit: cover; object-position: 50% 65%; }
.campus > span { position: absolute; bottom: 18px; left: 22px; font-size: 13px; padding: 5px 12px; border: 1px solid var(--ink); border-radius: 5px; background: var(--paper); }
.about { padding-block: 100px; }
.section-heading { display: flex; align-items: end; justify-content: space-between; gap: 32px; margin-bottom: 44px; }
h2 { font-size: clamp(28px, 3.2vw, 40px); line-height: 1.45; letter-spacing: -.025em; font-weight: 750; }
.section-heading p, .tools p, .join-message p { font-size: 15px; color: var(--muted); }
.feature { display: grid; grid-template-columns: 1fr 1.6fr auto; align-items: start; gap: 36px; padding-block: 28px; border-top: 1px solid var(--line); }
.feature:last-child { border-bottom: 1px solid var(--line); }
h3 { font-size: 19px; font-weight: 700; }
.feature p { max-width: 440px; color: var(--muted); font-size: 15px; }
.feature-tag { font-size: 12px; padding: 3px 10px; border: 1px solid var(--ink); border-radius: 5px; white-space: nowrap; background: var(--yellow); }
.tools { background: #e8efda; border-block: 1px solid #cdd8ba; }
.tools-inner { padding-block: 64px; display: grid; grid-template-columns: 1fr 1fr; gap: 70px; }
.tools-inner > div > p { margin-top: 18px; }
.tool-list > div { padding: 17px 0 23px; }
.tool-list > div + div { border-top: 1px solid #bdc8ab; padding-bottom: 0; }
.tool-list p { margin-top: 7px; }
.join { display: grid; grid-template-columns: 1fr 1fr; gap: 70px; align-items: center; padding-block: 100px 76px; scroll-margin-top: 24px; }
.join-message p { margin-top: 22px; }
.search-card { padding: 32px 24px 18px; background: var(--yellow); border: 2px solid var(--ink); border-radius: 14px; box-shadow: 5px 5px 0 var(--ink); text-align: center; }
.wechat-search { margin-bottom: 8px; }
.search-card > p { font-size: 13px; }
.search-card strong { display: block; font-size: 30px; margin: 5px 0 22px; letter-spacing: .05em; }
.search-card .button { background: var(--paper); width: 100%; max-width: 300px; }
.search-card .button:hover { background: var(--ground); }
.search-card .copy-status { margin-top: 16px; font-size: 12px; min-height: 42px; }
.questions { padding-bottom: 80px; }
.questions h2 { font-size: 23px; margin-bottom: 22px; }
details { border-bottom: 1px solid var(--line); }
summary { position: relative; padding: 20px 40px 20px 0; cursor: pointer; list-style: none; font-size: 15px; font-weight: 600; }
summary::-webkit-details-marker { display: none; }
summary::after { content: '+'; position: absolute; right: 4px; top: 17px; font-size: 22px; font-weight: 400; }
details[open] summary::after { content: '−'; }
details p { color: var(--muted); max-width: 700px; font-size: 14px; padding-bottom: 22px; }
.site-footer { display: flex; align-items: center; gap: 28px; border-top: 1px solid var(--line); padding-block: 28px 34px; }
.site-footer .brand { font-size: 15px; }
.site-footer p, .site-footer > span { font-size: 12px; color: var(--muted); }
.site-footer > span { margin-left: auto; }
@media (max-width: 760px) {
  .wrap { padding-inline: 24px; }
  .site-header { min-height: 84px; gap: 12px; }
  .brand { font-size: 17px; gap: 8px; }
  .brand img { width: 30px; height: 30px; }
  nav { gap: 16px; font-size: 13px; }
  .about-link { display: none; }
  .hero { display: block; padding-top: 30px; }
  h1 { font-size: clamp(38px, 9vw, 60px); }
  .hero-intro { margin-top: 22px; }
  .hero-intro > p:first-child { font-size: 15px; }
  .hero-intro .button { margin-top: 24px; }
  .conversation { max-width: 440px; margin: 46px auto 0; padding: 0 4px; }
  .conversation-title { font-size: 12px; margin-bottom: 20px; }
  .bubble { font-size: 17px; padding: 14px 18px; }
  .bubble-question { max-width: 90%; }
  .bubble-reply { max-width: 225px; margin-top: 18px; }
  .bubble-small { font-size: 14px; margin-top: 22px; margin-right: 10px; }
  .campus { height: 170px; margin-top: 34px; }
  .campus > span { left: 10px; bottom: 12px; font-size: 11px; padding-inline: 8px; }
  .about { padding-block: 60px; }
  .section-heading { display: block; margin-bottom: 28px; }
  .section-heading p { margin-top: 18px; font-size: 14px; }
  .feature { grid-template-columns: 1fr auto; gap: 10px; padding-block: 24px; }
  .feature h3 { font-size: 18px; }
  .feature p { grid-column: 1 / -1; grid-row: 2; font-size: 14px; }
  .feature-tag { font-size: 11px; }
  .tools-inner { grid-template-columns: 1fr; gap: 24px; padding-block: 44px; }
  .tools p { font-size: 14px; }
  .join { grid-template-columns: 1fr; gap: 30px; padding-block: 60px; }
  .join-message p { font-size: 14px; margin-top: 16px; }
  .search-card { max-width: 440px; width: 100%; margin-inline: auto; }
  .questions { padding-bottom: 56px; }
  .questions h2 { font-size: 22px; }
  .site-footer { flex-wrap: wrap; gap: 12px 20px; padding-block: 24px; }
  .site-footer p { margin-left: auto; }
  .site-footer > span { width: 100%; margin-left: 0; }
}
@media (prefers-reduced-motion: reduce) {
  :root { scroll-behavior: auto; }
  .button { transition: none; }
}