/* Seiwoong Hong — academic website */
:root {
  --text: #222222;
  --muted: #666666;
  --accent: #1f4e8c;   /* navy */
  --line: #e6e6e6;
  --bg: #ffffff;
  --soft: #f6f7f9;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Roboto", -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  font-weight: 300;
  font-size: 17px;
  line-height: 1.65;
}
strong, b { font-weight: 500; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* Navigation */
header { border-bottom: 1px solid var(--line); background: var(--bg); }
.nav {
  max-width: 900px; margin: 0 auto; padding: 14px 20px;
  display: flex; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap;
}
.nav .brand { color: var(--text); font-size: 19px; font-weight: 300; }
.nav .brand b { font-weight: 500; }
.nav ul { list-style: none; margin: 0; padding: 0; display: flex; gap: 26px; flex-wrap: wrap; }
.nav ul a { color: var(--text); font-size: 16px; font-weight: 400; }
.nav ul a:hover { color: var(--accent); text-decoration: none; }
.nav ul a.active { color: var(--accent); font-weight: 500; }

/* Page */
main { max-width: 900px; margin: 0 auto; padding: 44px 20px 64px; }
h1 { font-size: 40px; font-weight: 300; margin: 0 0 6px; line-height: 1.2; }
h1 b { font-weight: 500; }
.subtitle { color: var(--muted); font-size: 16px; margin: 0 0 28px; }
h2 {
  font-size: 22px; font-weight: 500; color: var(--accent);
  margin: 44px 0 18px; padding-bottom: 6px; border-bottom: 1px solid var(--line);
}
p { margin: 0 0 14px; }

/* About */
.profile { float: right; width: 230px; margin: 0 0 20px 32px; }
.profile img { width: 100%; border-radius: 4px; display: block; }
.contact { margin-top: 18px; }
.contact div { margin-bottom: 2px; }
.contact .label { display: inline-block; width: 64px; color: var(--muted); }
.clear { clear: both; }

.refs { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; font-size: 15.5px; line-height: 1.5; }
.refs strong { display: block; font-size: 16.5px; }

/* Papers */
.paper { margin: 0 0 34px; }
.paper .title { font-size: 18.5px; font-weight: 500; line-height: 1.4; }
.paper .title a { color: var(--accent); }
.paper .note { color: var(--muted); font-weight: 400; font-size: 16px; }
.paper .coauthors { color: var(--muted); font-size: 16px; margin-top: 2px; }
.paper .abstract { margin-top: 10px; font-size: 16px; }
.paper ul { margin: 10px 0 0; padding-left: 20px; font-size: 15.5px; }
.paper ul li { margin-bottom: 3px; }
.btns { margin-top: 8px; display: flex; gap: 8px; flex-wrap: wrap; }
.btns a {
  font-size: 13px; font-weight: 400; letter-spacing: .03em; text-transform: uppercase;
  padding: 2px 10px; border: 1px solid var(--accent); border-radius: 3px; color: var(--accent);
}
.btns a:hover { background: var(--accent); color: #fff; text-decoration: none; }

/* CV */
.cv-frame { width: 100%; height: 88vh; border: 1px solid var(--line); }

footer { border-top: 1px solid var(--line); color: var(--muted); font-size: 14px; text-align: center; padding: 22px 20px; }

@media (max-width: 680px) {
  h1 { font-size: 32px; }
  .profile { float: none; width: 180px; margin: 0 0 22px; }
  .refs { grid-template-columns: 1fr; gap: 16px; }
  .cv-frame { height: 75vh; }
}