:root {
  --paper: #ffffff;
  --ink: #1b1b1b;
  --green: #2f4f4a;
  --gray: #9a9a9a;
  --soft: #fcfcfc;
  --line: #ececec;
  --serif: "Songti SC", "STSong", "SimSun", "Noto Serif SC", "Source Han Serif SC", Georgia, serif;
  --sans: "PingFang SC", -apple-system, BlinkMacSystemFont, "Microsoft YaHei", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --max: 1080px;
  --radius: 10px;
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, .serif {
  font-family: var(--serif);
  font-weight: 600;
  line-height: 1.4;
  letter-spacing: 0.01em;
  margin: 0;
}

a { color: var(--green); text-decoration: none; transition: opacity .2s; }
a:hover { opacity: .7; }
img { max-width: 100%; display: block; }
p { margin: 0 0 1em; }

.container { max-width: var(--max); margin: 0 auto; padding: 0 24px; }

.eyebrow {
  font-size: 12px; letter-spacing: .2em; text-transform: uppercase;
  color: var(--gray); margin-bottom: 12px;
}

.muted { color: #777; }
.lead { font-size: 17px; color: #666; }

/* ---------- nav ---------- */
.site-nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.9);
  backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.site-nav .inner {
  max-width: var(--max); margin: 0 auto; padding: 15px 24px;
  display: flex; align-items: center; justify-content: space-between;
}
.brand { font-family: var(--serif); font-size: 18px; letter-spacing: .14em; color: var(--ink); }
.brand:hover { opacity: 1; }
.nav-links { display: flex; gap: 30px; font-size: 15px; }
.nav-links a { color: #5a5a5a; }
.nav-links a.active { color: var(--green); }
.nav-toggle {
  display: none; background: none; border: 0; font-size: 20px; color: var(--ink);
  cursor: pointer; padding: 4px 8px;
}

/* ---------- hero / profile ---------- */
.profile {
  display: grid; grid-template-columns: 1fr 1.35fr; gap: 56px;
  align-items: start; padding: 76px 0 24px;
}
.avatar {
  width: 104px; height: 104px; border-radius: 50%; background: #eaeaea;
  overflow: hidden; margin-bottom: 22px;
}
.avatar img { width: 100%; height: 100%; object-fit: cover; }
.profile h1 { font-size: clamp(26px, 3.4vw, 36px); margin-bottom: 14px; }
.profile .lead { margin-bottom: 22px; }
.socials { display: flex; gap: 10px; }
.socials a {
  width: 34px; height: 34px; border-radius: 50%; border: 1px solid var(--line);
  display: flex; align-items: center; justify-content: center; color: #888; font-size: 13px;
}
.socials a:hover { border-color: var(--green); color: var(--green); opacity: 1; }

.entries { display: flex; flex-direction: column; gap: 14px; }
.entry {
  display: block; border: 1px solid #e8e8e8; border-radius: var(--radius);
  padding: 20px 24px; background: #fff; transition: .22s;
}
.entry:hover { border-color: var(--green); transform: translateY(-2px); opacity: 1; }
.entry h3 { font-size: 18px; margin-bottom: 6px; }
.entry p { margin: 0; font-size: 13.5px; color: #999; }

/* ---------- sections ---------- */
.section { padding: 60px 0; }
.section.soft { background: var(--soft); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.section-title { font-size: clamp(22px, 3vw, 30px); margin-bottom: 10px; }
.section-sub { color: #888; margin-bottom: 36px; }

/* ---------- grid & cards ---------- */
.grid { display: grid; gap: 18px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }

.card {
  border: 1px solid #e8e8e8; border-radius: var(--radius); background: #fff;
  padding: 24px; transition: .22s;
}
.card:hover { border-color: var(--green); transform: translateY(-2px); opacity: 1; }
.card h3 { font-size: 18px; margin-bottom: 8px; }
.card p { margin: 0; font-size: 14px; color: #777; }
.card .thumb { height: 96px; border-radius: 7px; background: #f1f1f1; margin-bottom: 16px; }

.course-card { display: flex; flex-direction: column; height: 100%; }
.course-card .who { font-size: 12.5px; color: var(--gray); margin-bottom: 12px; }
.course-card .more { margin-top: auto; padding-top: 16px; font-size: 13.5px; color: var(--green); }

.group-head {
  display: flex; align-items: baseline; gap: 12px; margin: 8px 0 22px;
  padding-left: 14px; border-left: 3px solid var(--green);
}
.group-head h3 { font-size: 20px; }
.group-head span { font-size: 13px; color: var(--gray); }
.section + .group-head { margin-top: 44px; }

/* ---------- buttons ---------- */
.btn {
  display: inline-block; font-size: 14px; font-family: var(--sans);
  padding: 11px 26px; border-radius: 5px; border: 1px solid var(--green);
  background: var(--green); color: #fff; cursor: pointer; transition: .2s;
}
.btn:hover { opacity: .85; }
.btn.ghost { background: transparent; color: var(--green); }

/* ---------- timeline ---------- */
.timeline { list-style: none; padding: 0; margin: 0; }
.timeline li { display: flex; gap: 22px; padding: 14px 0; border-bottom: 1px solid var(--line); }
.timeline .year { font-family: var(--serif); color: var(--green); min-width: 104px; }

/* ---------- media columns ---------- */
.media-col h3 { font-size: 18px; margin-bottom: 16px; }
.media-item {
  border: 1px solid #e8e8e8; border-radius: 8px; padding: 14px 18px;
  margin-bottom: 10px; font-size: 14px; color: #555; background: #fff;
}
.media-item:hover { border-color: var(--green); opacity: 1; }

/* ---------- footer ---------- */
.site-footer {
  border-top: 1px solid var(--line); background: var(--soft);
  margin-top: 60px; padding: 56px 0 28px;
}
.foot-grid { display: grid; grid-template-columns: 1.4fr 1.4fr 1fr; gap: 40px; }
.foot-brand { font-family: var(--serif); font-size: 20px; letter-spacing: .06em; margin-bottom: 10px; }
.foot-title { font-size: 12px; letter-spacing: .16em; text-transform: uppercase; color: var(--gray); margin-bottom: 16px; }
.qr-row { display: flex; gap: 20px; margin-bottom: 16px; }
.qr { text-align: center; font-size: 12px; color: #999; }
.qr-box {
  width: 96px; height: 96px; border: 1px solid #e2e2e2; border-radius: 8px; background: #fff;
  margin-bottom: 8px; display: flex; align-items: center; justify-content: center;
  font-size: 11px; color: #ccc;
}
.qr-box img { width: 100%; height: 100%; object-fit: contain; border-radius: 8px; }
.copy {
  font-family: var(--sans); font-size: 13px; color: var(--green);
  background: none; border: 1px dashed #cfcfcf; border-radius: 6px;
  padding: 8px 14px; cursor: pointer;
}
.copy:hover { border-color: var(--green); }
.foot-nav a { display: block; color: #666; font-size: 14px; margin-bottom: 10px; }
.foot-bottom {
  margin-top: 40px; padding-top: 22px; border-top: 1px solid var(--line);
  font-size: 12.5px; color: #aaa; display: flex; justify-content: space-between; flex-wrap: wrap; gap: 10px;
}

/* ---------- responsive ---------- */
@media (max-width: 860px) {
  .profile { grid-template-columns: 1fr; gap: 40px; padding-top: 52px; }
  .grid-3 { grid-template-columns: 1fr 1fr; }
  .foot-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 620px) {
  .nav-toggle { display: block; }
  .nav-links {
    display: none; position: absolute; top: 100%; left: 0; right: 0;
    flex-direction: column; gap: 0; background: #fff; border-bottom: 1px solid var(--line);
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 14px 24px; border-top: 1px solid var(--line); }
  .grid-2, .grid-3 { grid-template-columns: 1fr; }
  .foot-grid { grid-template-columns: 1fr; }
}