/* ==========================================================
   Yoonseok Heo — personal academic homepage
   Style inspired by clean lab sites: fixed blurred nav,
   alternating bands, stat tiles, venue badges.
   ========================================================== */
:root{
  --fg:#1e1e1e; --fg2:#454545; --fg3:#7a6f70; --fg4:#a89c9d;
  --line:#e8dedd; --bg:#ffffff; --bg2:#faf6f5; --bg3:#f3e9e8;
  --accent:#AF272F; --accent2:#9E2A2B; --accent-soft:#f7e6e6;
  --blue:#00558C; --purple:#642F6C;
  --gold:#b8791a; --gold-soft:#fbf1dc;
  --radius:14px; --shadow:0 6px 24px rgba(120,40,40,.08);
}
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{font-size:16px;scroll-behavior:smooth;scroll-padding-top:72px}
body{font-family:"DM Sans","Noto Sans KR",-apple-system,system-ui,"Apple SD Gothic Neo",sans-serif;background:var(--bg);color:var(--fg);line-height:1.6;-webkit-font-smoothing:antialiased}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
.inner{max-width:1080px;margin:0 auto;padding:0 40px}
@media(max-width:640px){.inner{padding:0 20px}}

/* ---------- nav ---------- */
nav.top{position:fixed;top:0;left:0;right:0;z-index:100;height:60px;background:rgba(255,255,255,.9);backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);border-bottom:1px solid var(--line)}
nav.top .inner{height:100%;display:flex;align-items:center;justify-content:space-between}
.logo{display:flex;align-items:center;gap:10px;font-weight:800;letter-spacing:-.02em;font-size:17px}
.logo .mark{width:32px;height:32px;display:block}
.logo small{font-weight:500;color:var(--fg3);font-size:12px;margin-left:2px}
.links{display:flex;gap:28px;align-items:center}
.links a{font-size:12.5px;font-weight:600;color:var(--fg3);letter-spacing:.06em;text-transform:uppercase;transition:color .2s}
.links a:hover,.links a.active{color:var(--fg)}
.burger{display:none;background:none;border:0;cursor:pointer;padding:6px}
.burger svg{width:24px;height:24px}
@media(max-width:760px){
  .links{display:none;position:absolute;top:60px;left:0;right:0;background:#fff;border-bottom:1px solid var(--line);flex-direction:column;gap:0;padding:8px 0}
  .links.open{display:flex}
  .links a{padding:12px 24px;width:100%}
  .burger{display:block}
}

/* ---------- bands ---------- */
main{padding-top:60px}
.band{padding:72px 0}
.band-off{background:var(--bg2)}
.band-tint{background:linear-gradient(180deg,var(--bg3),var(--bg2))}
.sec-head{display:flex;align-items:baseline;justify-content:space-between;gap:16px;margin-bottom:32px;flex-wrap:wrap}
.sec-head h2{font-size:clamp(24px,3vw,32px);font-weight:800;letter-spacing:-.03em;line-height:1.15}
.sec-head p{color:var(--fg2);margin-top:8px;max-width:640px}
.more{font-size:12.5px;font-weight:700;color:var(--fg3);letter-spacing:.05em;text-transform:uppercase}
.more:hover{color:var(--fg)}
.eyebrow{display:inline-block;font-size:12px;font-weight:700;letter-spacing:.12em;text-transform:uppercase;color:var(--accent);margin-bottom:12px}

/* ---------- hero ---------- */
.hero{padding:80px 0 64px;background:radial-gradient(1200px 500px at 80% -10%,var(--accent-soft),transparent 60%),var(--bg)}
.hero .grid{display:grid;grid-template-columns:1.25fr .9fr;gap:56px;align-items:center}
.hero h1{font-size:clamp(34px,5vw,56px);font-weight:800;letter-spacing:-.04em;line-height:1.05}
.hero h1 em{font-style:italic;color:var(--accent)}
.hero .name{margin-top:18px;font-size:20px;font-weight:700}
.hero .name span{font-weight:500;color:var(--fg3);margin-left:8px}
.hero .lead{margin-top:14px;color:var(--fg2);font-size:16.5px;max-width:560px}
.hero .cta{display:flex;gap:12px;margin-top:28px;flex-wrap:wrap}
.btn{display:inline-flex;align-items:center;gap:8px;padding:11px 18px;border-radius:10px;font-weight:700;font-size:14px;border:1px solid var(--line);background:#fff;color:var(--fg);transition:all .2s}
.btn:hover{border-color:var(--accent);color:var(--accent)}
.btn.primary{background:var(--accent);border-color:var(--accent);color:#fff}
.btn.primary:hover{background:var(--accent2);color:#fff}
.portrait{position:relative}
.portrait img{width:100%;aspect-ratio:4/4.6;object-fit:cover;object-position:52% 20%;border-radius:22px;box-shadow:var(--shadow)}
.portrait .tag{position:absolute;left:16px;bottom:16px;background:rgba(255,255,255,.92);backdrop-filter:blur(8px);border:1px solid var(--line);border-radius:10px;padding:8px 12px;font-size:12.5px;font-weight:600;color:var(--fg2)}
@media(max-width:860px){.hero .grid{grid-template-columns:1fr}.portrait{max-width:360px}}

/* ---------- stats ---------- */
.stats{display:grid;grid-template-columns:repeat(5,1fr);gap:14px;margin-top:40px}
.stat{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:20px 18px;transition:transform .2s,box-shadow .2s}
.stat:hover{transform:translateY(-2px);box-shadow:var(--shadow)}
.stat b{display:block;font-size:30px;font-weight:800;letter-spacing:-.03em;color:var(--accent2)}
.stat span{font-size:12.5px;font-weight:600;color:var(--fg3);line-height:1.35;display:block;margin-top:4px}
@media(max-width:860px){.stats{grid-template-columns:repeat(3,1fr)}}
@media(max-width:520px){.stats{grid-template-columns:repeat(2,1fr)}}

/* ---------- cards ---------- */
.cards{display:grid;grid-template-columns:repeat(2,1fr);gap:18px}
.cards.four{grid-template-columns:repeat(4,1fr)}
.cards.three{grid-template-columns:repeat(3,1fr)}
@media(max-width:900px){.cards.four,.cards.three{grid-template-columns:repeat(2,1fr)}}
@media(max-width:600px){.cards,.cards.four,.cards.three{grid-template-columns:1fr}}
.card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:24px;transition:transform .2s,box-shadow .2s;display:flex;flex-direction:column;gap:10px}
.card:hover{transform:translateY(-3px);box-shadow:var(--shadow)}
.card .icon{width:40px;height:40px;border-radius:11px;background:var(--accent-soft);color:var(--accent2);display:grid;place-items:center;font-size:19px}
.card h3{font-size:17px;font-weight:800;letter-spacing:-.02em;line-height:1.3}
.card p{font-size:14px;color:var(--fg2)}
.card .tags{display:flex;flex-wrap:wrap;gap:6px;margin-top:auto;padding-top:6px}
.tag-chip{font-size:11.5px;font-weight:600;color:var(--fg3);background:var(--bg2);border-radius:999px;padding:3px 9px}

/* ---------- news ---------- */
.news{list-style:none;display:grid;gap:0;border-top:1px solid var(--line)}
.news li{display:grid;grid-template-columns:110px 130px 1fr;gap:16px;padding:16px 0;border-bottom:1px solid var(--line);align-items:baseline}
.news .date{font-size:13px;color:var(--fg3);font-weight:600;font-variant-numeric:tabular-nums}
.news .kind{font-size:11px;font-weight:800;letter-spacing:.08em;text-transform:uppercase;color:var(--accent2)}
.news .kind.award{color:var(--gold)}
.news .txt{font-size:15px}
@media(max-width:640px){.news li{grid-template-columns:1fr}.news li .kind{margin-top:-6px}}

/* ---------- publications ---------- */
.filters{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:28px}
.filters button{border:1px solid var(--line);background:#fff;border-radius:999px;padding:7px 14px;font-size:13px;font-weight:600;color:var(--fg2);cursor:pointer;font-family:inherit;transition:all .15s}
.filters button:hover{border-color:var(--accent);color:var(--accent)}
.filters button.on{background:var(--fg);color:#fff;border-color:var(--fg)}
.year{font-size:22px;font-weight:800;letter-spacing:-.03em;margin:36px 0 12px;padding-bottom:8px;border-bottom:2px solid var(--fg)}
.year:first-child{margin-top:0}
.pub{display:grid;grid-template-columns:1fr auto;gap:14px;padding:18px 0;border-bottom:1px solid var(--line);align-items:start}
.pub .venue{display:inline-flex;align-items:center;gap:6px;font-size:11.5px;font-weight:800;letter-spacing:.04em;text-transform:uppercase;color:var(--accent2);background:var(--accent-soft);border-radius:6px;padding:3px 8px;margin-bottom:8px}
.pub .venue.award{color:var(--gold);background:var(--gold-soft)}
.pub .venue.domestic{color:var(--blue);background:#e6eef5}
.pub .venue.preprint{color:#6b7280;background:#f1f2f4}
.pub h4{font-size:16.5px;font-weight:700;letter-spacing:-.01em;line-height:1.35}
.pub h4 a:hover{color:var(--accent)}
.pub .authors{font-size:14px;color:var(--fg2);margin-top:4px}
.pub .authors b{color:var(--fg);font-weight:700}
.pub .where{font-size:13px;color:var(--fg3);margin-top:2px}
.pub .links{display:flex;flex-direction:column;gap:6px;align-items:flex-end}
.pub .links a{font-size:12px;font-weight:700;color:var(--fg3);border:1px solid var(--line);padding:5px 10px;border-radius:8px;white-space:nowrap}
.pub .links a:hover{color:var(--accent);border-color:var(--accent)}
.pub .cites{font-size:12px;color:var(--fg4);font-weight:600}
@media(max-width:600px){.pub{grid-template-columns:1fr}.pub .links{flex-direction:row;align-items:center;flex-wrap:wrap}}
.pub-compact .pub{padding:14px 0}

/* ---------- courses ---------- */
.course{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:24px;display:flex;flex-direction:column;gap:10px}
.course .meta{display:flex;gap:8px;flex-wrap:wrap;font-size:12px;font-weight:700}
.course .code{color:var(--accent2);background:var(--accent-soft);border-radius:6px;padding:3px 8px}
.course .term{color:var(--fg3);background:var(--bg2);border-radius:6px;padding:3px 8px}
.course h3{font-size:18px;font-weight:800;letter-spacing:-.02em;line-height:1.3}
.course h3 small{display:block;font-weight:500;color:var(--fg3);font-size:13.5px;margin-top:2px}
.course p{font-size:14px;color:var(--fg2)}
.course dl{display:grid;grid-template-columns:auto 1fr;gap:4px 12px;font-size:13px;margin-top:4px}
.course dt{color:var(--fg3);font-weight:600}
.course dd{color:var(--fg2)}
.course details{margin-top:6px;font-size:13.5px}
.course summary{cursor:pointer;font-weight:700;color:var(--fg3)}
.course summary:hover{color:var(--accent)}
.course ol{margin:10px 0 0 18px;color:var(--fg2);display:grid;gap:4px}
.course .foot{margin-top:auto;padding-top:10px;display:flex;gap:8px;flex-wrap:wrap}

/* ---------- projects ---------- */
.project{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:26px;display:grid;grid-template-columns:1fr auto;gap:18px}
.project .period{font-size:13px;font-weight:700;color:var(--fg3)}
.project h3{font-size:19px;font-weight:800;letter-spacing:-.02em;margin-top:6px;line-height:1.35}
.project .funder{font-size:14px;color:var(--fg2);margin-top:6px}
.project .status{align-self:start;font-size:12px;font-weight:800;color:var(--blue);background:#e6eef5;border-radius:999px;padding:5px 11px;white-space:nowrap}
.project .tags{display:flex;gap:6px;flex-wrap:wrap;margin-top:12px}
@media(max-width:600px){.project{grid-template-columns:1fr}}

/* ---------- about / contact ---------- */
.two{display:grid;grid-template-columns:1.1fr .9fr;gap:40px}
@media(max-width:800px){.two{grid-template-columns:1fr}}
.prose p{color:var(--fg2);margin-bottom:12px;font-size:15.5px}
.kv{list-style:none;display:grid;gap:10px}
.kv li{display:grid;grid-template-columns:110px 1fr;gap:12px;font-size:14.5px;border-bottom:1px dashed var(--line);padding-bottom:10px}
.kv li span{color:var(--fg3);font-weight:600}
.kv li a{color:var(--accent2);font-weight:600}
.interests{display:flex;flex-wrap:wrap;gap:8px}
.interests span{background:#fff;border:1px solid var(--line);border-radius:999px;padding:6px 12px;font-size:13px;font-weight:600;color:var(--fg2)}

/* ---------- page header ---------- */
.page-head{padding:64px 0 40px;background:linear-gradient(180deg,var(--bg3),#fff)}
.page-head h1{font-size:clamp(30px,4vw,44px);font-weight:800;letter-spacing:-.04em}
.page-head p{color:var(--fg2);margin-top:10px;max-width:640px}

/* ---------- footer ---------- */
footer{border-top:1px solid var(--line);padding:40px 0;background:var(--bg2);font-size:13.5px;color:var(--fg3)}
footer .inner{display:flex;justify-content:space-between;gap:20px;flex-wrap:wrap}
footer b{color:var(--fg)}
footer a:hover{color:var(--fg)}

/* ---------- members ---------- */
.prof{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:28px;display:grid;grid-template-columns:220px 1fr;gap:28px;align-items:start}
.prof img{width:220px;height:260px;object-fit:cover;object-position:52% 15%;border-radius:16px}
.prof h3{font-size:24px;font-weight:800;letter-spacing:-.03em}
.prof .role{color:var(--accent2);font-weight:700;margin-top:2px}
.prof .kv{margin-top:14px}
.prof .kv li{grid-template-columns:120px 1fr}
.prof .cta{display:flex;gap:8px;flex-wrap:wrap;margin-top:16px}
@media(max-width:700px){.prof{grid-template-columns:1fr}.prof img{width:100%;height:auto;aspect-ratio:1/1.1}}
.member{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:22px;display:flex;flex-direction:column;gap:8px;transition:transform .2s,box-shadow .2s}
.member:hover{transform:translateY(-3px);box-shadow:var(--shadow)}
.avatar{width:64px;height:64px;border-radius:50%;display:grid;place-items:center;font-weight:800;font-size:20px;color:#fff;background:linear-gradient(135deg,var(--accent),var(--purple));margin-bottom:4px;letter-spacing:-.02em}
.avatar.alt{background:linear-gradient(135deg,var(--blue),var(--purple))}
.avatar img{width:100%;height:100%;object-fit:cover;border-radius:50%}
.member h3{font-size:17px;font-weight:800;letter-spacing:-.02em;line-height:1.3}
.member h3 small{display:block;font-weight:500;color:var(--fg3);font-size:13px;margin-top:2px}
.member .role{font-size:12px;font-weight:800;letter-spacing:.06em;text-transform:uppercase;color:var(--accent2)}
.member .prog{font-size:13.5px;color:var(--fg2)}
.member .topic{font-size:12px;font-weight:700;color:var(--fg3);margin-top:6px}
.member .tags{display:flex;flex-wrap:wrap;gap:6px}
.join{background:linear-gradient(120deg,var(--accent2),var(--purple) 70%,var(--blue));color:#fff;border-radius:var(--radius);padding:36px;display:flex;justify-content:space-between;align-items:center;gap:20px;flex-wrap:wrap}
.join h2{font-size:26px;font-weight:800;letter-spacing:-.03em}
.join p{opacity:.9;margin-top:6px;max-width:560px}
.join .btn{background:#fff;color:var(--accent2);border-color:#fff}