:root {
  color-scheme: light;
  --ink: #262b2d;
  --paper: #e8e9e7;
  --nav: #303536;
  --link: #225f73;
  --muted: #576267;
  --line: #c4cccd;
}

* { box-sizing: border-box; }
html { scroll-padding-top: 1rem; }
body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--paper);
  color: var(--ink);
  font: 17px/1.7 Arial, Helvetica, sans-serif;
}
a { color: var(--link); text-underline-offset: 3px; text-decoration-thickness: 1px; overflow-wrap: anywhere; }
a:hover { color: #102f3b; }
a:focus-visible, object:focus-visible { outline: 3px solid #b27822; outline-offset: 5px; }
.skip-link { position: absolute; top: -6rem; left: 1rem; z-index: 10; padding: .5rem 1rem; background: white; }
.skip-link:focus { top: .5rem; }
.topnav { background: var(--nav); }
.nav-inner { display: flex; flex-wrap: wrap; gap: 0; padding: 0 28px; }
.topnav a {
  display: block;
  padding: 12px 20px;
  color: #f5f5f3;
  font-size: 16px;
  line-height: 1.5;
  text-decoration: none;
  border-bottom: 3px solid transparent;
}
.topnav a:hover { background: #485052; }
.topnav a[aria-current="page"] { border-bottom-color: #b4d5dd; background: #3d4547; }
.topnav a:focus-visible { outline-offset: -5px; outline-color: #e7c37f; }
.banner {
  display: flex;
  min-height: 246px;
  border-bottom: 5px solid var(--nav);
  background: #66828d;
}
.banner-home { min-height: 305px; }
.banner-scene {
  min-width: 0;
  flex: 1;
  display: flex;
  align-items: center;
  padding: 36px 48px;
  color: #fff;
  background-image: linear-gradient(90deg, rgba(17, 31, 41, .76), rgba(17, 31, 41, .28) 66%, rgba(17, 31, 41, .06)), url("picture/4.jpg");
  background-size: cover;
  background-position: center 58%;
}
.banner-home .banner-scene {
  background-image: linear-gradient(90deg, rgba(17, 31, 41, .76), rgba(17, 31, 41, .28) 66%, rgba(17, 31, 41, .06)), url("picture/beijing-home-2026-10-14.jpg");
  background-position: center 57%;
  background-repeat: no-repeat;
}
.banner-blog .banner-scene {
  background-image: linear-gradient(90deg, rgba(15, 37, 39, .78), rgba(15, 37, 39, .16)), url("picture/2.jpg");
  background-position: center 51%;
}
.banner-contact .banner-scene {
  background-image: linear-gradient(90deg, rgba(18, 25, 32, .7), rgba(18, 25, 32, .05)), url("picture/5.jpg");
  background-position: center 55%;
}
.banner h1, .banner-title {
  margin: 0;
  font-size: clamp(38px, 4.7vw, 62px);
  line-height: 1.15;
  letter-spacing: -.025em;
  font-weight: 700;
  text-shadow: 0 2px 16px rgba(0, 0, 0, .18);
}
.banner h1 span[lang] { white-space: nowrap; }
.banner-subtitle { margin: 12px 0 0; font-size: 17px; color: #f0f4f5; }
.portrait {
  display: block;
  width: 248px;
  height: 300px;
  object-fit: contain;
  background: #fff;
  border-left: 5px solid var(--nav);
}
.content {
  width: 100%;
  max-width: 1200px;
  padding: 34px 48px 48px;
  flex: 1;
}
.home-copy { max-width: 1050px; }
p { margin: 0 0 20px; }
ul, ol { margin: 0 0 24px; padding-left: 24px; }
li { padding-left: 4px; margin: 0 0 12px; }
h2 { font-size: 25px; line-height: 1.35; margin: 0 0 20px; }
.content section + section { margin-top: 34px; padding-top: 28px; border-top: 1px solid var(--line); }
.research-list li { margin-bottom: 24px; }
.research-list p { margin: 4px 0 0; }
.meta, time { color: var(--muted); font-size: 15px; }
.inline-links { display: flex; flex-wrap: wrap; gap: 10px 26px; margin-top: 28px; }
.post-list { list-style: none; padding: 0; margin: 0; }
.post-list li { margin: 0; padding: 22px 0; border-bottom: 1px solid var(--line); }
.post-list li:first-child { padding-top: 0; }
.post-list h2 { margin: 4px 0 0; font-size: 21px; font-weight: 400; line-height: 1.5; }
.article-title { max-width: 960px; margin: 12px 0 24px; font-size: clamp(27px, 3.3vw, 36px); line-height: 1.3; letter-spacing: -.02em; }
.article-body { max-width: 950px; }
.back-link { display: inline-block; margin-bottom: 24px; font-size: 15px; }
.pdf-frame { width: 100%; height: 780px; border: 1px solid #b9c2c3; background: #fff; }
.footer { background: #c9cecd; color: #394447; padding: 14px 48px; font-size: 14px; }
.footer-inner { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 6px 24px; }
.footer p { margin: 0; }
.footer a { color: #254c5b; }
.footer .affiliation { color: #485458; }

@media (max-width: 1100px) {
  /* Keep the central city view in the banner on narrower screens. */
  .banner-home .banner-scene { background-size: auto 450%; }
}
@media (min-width: 1600px) {
  .nav-inner { padding-left: calc((100vw - 1504px) / 2); }
  .banner-scene { padding-left: calc((100vw - 1464px) / 2); }
  .content { margin-left: max(0px, calc((100vw - 1560px) / 2)); }
  .footer { padding-left: calc((100vw - 1464px) / 2); }
}
@media (max-width: 700px) {
  body { font-size: 16px; }
  .nav-inner { padding: 0 10px; }
  .topnav a { padding: 12px 13px; font-size: 15px; }
  .banner { min-height: 190px; }
  .banner-home { min-height: 225px; }
  .banner-scene { padding: 26px 24px; }
  .banner h1, .banner-title { font-size: 38px; }
  .banner-home h1 { font-size: 34px; }
  .banner-home h1 span[lang] { display: block; margin-top: 9px; font-size: 27px; letter-spacing: .04em; }
  .name-separator { display: none; }
  .banner-subtitle { font-size: 14px; }
  .portrait { width: 154px; height: 220px; object-fit: contain; object-position: center; border-left-width: 4px; }
  .content { padding: 28px 24px 36px; }
  .footer { padding: 15px 24px; }
  .pdf-frame { height: 620px; }
}
@media (max-width: 390px) {
  .nav-inner { padding: 0 5px; }
  .topnav a { padding-right: 10px; padding-left: 10px; }
  .banner-scene { padding: 24px 18px; }
  .banner-home h1 { font-size: 30px; }
  .portrait { width: 128px; }
  .content { padding: 26px 20px 34px; }
  .footer { padding: 14px 20px; }
}
@media print {
  .topnav, .skip-link, .pdf-frame { display: none; }
  body { background: white; font-size: 11pt; }
  .banner, .banner-home { min-height: 0; border-bottom: 1px solid #aaa; }
  .banner-scene, .banner-home .banner-scene { background: none; color: #000; padding: 20px 0; }
  .banner h1, .banner-title { font-size: 28pt; text-shadow: none; }
  .banner-subtitle { color: #333; }
  .portrait { width: 100px; height: 121px; border: 0; }
  .content { padding: 20px 0; }
  .footer { background: white; padding: 12px 0; border-top: 1px solid #aaa; }
  a { color: #000; }
}