:root {
  --navy: #0b2545;
  --navy-2: #13315c;
  --accent: #1d6fe0;
  --accent-ink: #1559b8;
  --accent-soft: #e8f1fd;
  --ink: #1b2430;
  --muted: #5b6676;
  --surface: #f5f7fa;
  --line: #e3e8ef;
  --radius: 14px;
  --shadow: 0 1px 2px rgb(16 24 40 / 6%), 0 4px 16px rgb(16 24 40 / 6%);
  --max: 1120px;
  --gutter: max(1.25rem, (100% - var(--max)) / 2);
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-padding-top: 5rem; }

body {
  margin: 0;
  font-family: "Pretendard Variable", Pretendard, system-ui, -apple-system, "Segoe UI",
    Roboto, "Apple SD Gothic Neo", "Noto Sans KR", "Malgun Gothic", sans-serif;
  font-size: 1rem;
  line-height: 1.7;
  color: var(--ink);
  background: #fff;
  word-break: keep-all;
  overflow-wrap: break-word;
}

img { max-width: 100%; height: auto; display: block; }

a { color: var(--accent-ink); text-underline-offset: 0.2em; text-decoration-thickness: 1px; }
a:hover { color: var(--accent); text-decoration-thickness: 2px; }

h1, h2, h3 { line-height: 1.3; color: var(--navy); letter-spacing: -0.01em; }
h2 { font-size: 1.5rem; margin: 0 0 1.1rem; font-weight: 700; }
h3 { font-size: 1.12rem; margin: 0 0 0.5rem; font-weight: 700; }
h2 a, h3 a { color: inherit; }

p { margin: 0 0 0.8rem; }
ul, ol { margin: 0 0 0.9rem; padding-left: 1.3rem; }
li { margin-bottom: 0.35rem; }
li::marker { color: #9aa6b6; }
li > ul, li > ol { margin-top: 0.35rem; }
strong { font-weight: 650; }

/* ---- header / footer ---- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0 2rem;
  padding: 0 var(--gutter);
  background: rgb(255 255 255 / 92%);
  backdrop-filter: saturate(180%) blur(10px);
  -webkit-backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--line);
}

.site-header a { text-decoration: none; }

.brand {
  padding: 0.9rem 0;
  font-size: 1.08rem;
  font-weight: 750;
  color: var(--navy);
  white-space: nowrap;
}


.brand:hover { color: var(--navy); }

.site-header nav { display: flex; gap: 0.15rem; }

.site-header nav a {
  position: relative;
  padding: 1.05rem 0.75rem;
  color: var(--muted);
  font-size: 0.95rem;
  font-weight: 550;
  white-space: nowrap;
}

.site-header nav a:hover { color: var(--navy); }

.site-header nav a[aria-current="page"] { color: var(--navy); }

.site-header nav a[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 0.75rem;
  right: 0.75rem;
  bottom: 0;
  height: 3px;
  border-radius: 3px 3px 0 0;
  background: var(--accent);
}

.site-footer {
  margin-top: 4rem;
  padding: 2.25rem var(--gutter);
  background: var(--navy);
  color: #c9d4e3;
  font-size: 0.875rem;
}

.site-footer p { margin: 0; max-width: 46rem; }

/* ---- shared blocks ---- */

.wrap { padding: 2.75rem var(--gutter) 0.5rem; }

main > section > h2:first-child,
.rule > h2 {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

main > section > h2:first-child::before,
.rule > h2::before {
  content: "";
  flex: none;
  width: 4px;
  height: 1.1em;
  border-radius: 2px;
  background: var(--accent);
}

.band { background: var(--surface); }

.page-title {
  background:
    radial-gradient(60rem 18rem at 85% -40%, rgb(29 111 224 / 18%), transparent 70%),
    linear-gradient(180deg, #f3f7fd, #fff);
  border-bottom: 1px solid var(--line);
}

.page-title h1 {
  margin: 0;
  padding: 2.75rem var(--gutter) 2.25rem;
  font-size: clamp(1.75rem, 4vw, 2.4rem);
  font-weight: 800;
}

.lead { font-size: 1.08rem; font-weight: 600; color: var(--navy-2); }

.button {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.6rem 1.25rem;
  border-radius: 999px;
  background: var(--navy);
  color: #fff;
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  transition: background 0.15s;
}

.button::after { content: "→"; }
.button:hover { background: var(--accent); color: #fff; }

/* ---- home ---- */

.hero {
  position: relative;
  padding: clamp(4rem, 10vw, 7.5rem) var(--gutter) clamp(9rem, 22vw, 15rem);
  background:
    linear-gradient(180deg, rgb(255 255 255 / 70%) 0%, rgb(255 255 255 / 35%) 45%, rgb(255 255 255 / 0%) 70%),
    #dfe8f1 url("/images/hero.png") center bottom / cover no-repeat;
  text-align: center;
}

.hero h1 {
  margin: 0 0 1rem;
  font-size: clamp(2.1rem, 6vw, 3.6rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--navy);
}

.hero p {
  display: inline-block;
  margin: 0;
  padding: 0.6rem 1.1rem;
  border-radius: 12px;
  background: rgb(255 255 255 / 72%);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  font-size: clamp(0.95rem, 2vw, 1.12rem);
  font-weight: 600;
  line-height: 1.55;
  color: var(--navy-2);
}

.intro { background: #fff; }
.intro .wrap { max-width: 52rem; margin: 0 auto; padding: 3.5rem 1.25rem 1rem; }

.tagline {
  margin-bottom: 1.5rem;
  font-size: clamp(1.25rem, 2.6vw, 1.6rem);
  font-weight: 700;
  line-height: 1.45;
  letter-spacing: -0.01em;
  color: var(--navy);
  text-align: center;
}

.intro p:not(.tagline) { color: #3a4553; font-size: 1.04rem; }

.products {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
  padding-bottom: 1rem;
}

.product {
  display: flex;
  flex-direction: column;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
  box-shadow: var(--shadow);
}

.product img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  object-position: top left;
  border-bottom: 1px solid var(--line);
}

.product > div { padding: 1.4rem 1.5rem 1.5rem; }
.product h2 { margin-bottom: 0.4rem; font-size: 1.3rem; }
.product p { color: var(--muted); }
.product p:last-child { margin: 1rem 0 0; }

/* ---- members ---- */

.person {
  display: grid;
  grid-template-columns: 11rem 1fr;
  gap: 1.75rem;
  align-items: start;
  margin-bottom: 1.5rem;
  padding: 1.5rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
  box-shadow: var(--shadow);
}

.person img {
  width: 100%;
  aspect-ratio: 4 / 5;
  object-fit: cover;
  border-radius: 10px;
}

.person h3 { font-size: 1.25rem; margin-bottom: 0.9rem; }

.person p, .person li, .people p { font-size: 0.94rem; }
.person p strong { color: var(--navy-2); }
.person ul { margin-bottom: 0.7rem; }

.people {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(15.5rem, 1fr));
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.people article {
  padding: 1.1rem 1.2rem;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--surface);
}

.people h3 { font-size: 1.02rem; margin-bottom: 0.35rem; }
.people p { margin-bottom: 0.25rem; color: var(--muted); }
.people p strong { color: var(--ink); }

.alumni { columns: 2 18rem; column-gap: 2.5rem; }
.alumni li { break-inside: avoid; }

/* ---- research & development ---- */

.two-col { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1.25rem; }

.two-col > div {
  padding: 1.5rem;
  border-radius: var(--radius);
  background: var(--surface);
}

.feature {
  display: grid;
  grid-template-columns: 2fr 3fr;
  gap: 2rem;
  align-items: center;
  margin: 1.75rem 0 2.25rem;
}

.feature img { border-radius: 12px; box-shadow: var(--shadow); }
.feature:nth-of-type(even) img { order: 2; }
.feature:nth-of-type(even) { grid-template-columns: 3fr 2fr; }

.projects { padding: 0; list-style: none; display: grid; gap: 0.9rem; }

.projects > li {
  margin: 0;
  padding: 1.1rem 1.3rem;
  border: 1px solid var(--line);
  border-left: 4px solid var(--accent);
  border-radius: 10px;
  background: #fff;
}

.projects > li > ul { margin: 0.5rem 0 0; color: var(--muted); font-size: 0.94rem; }

/* ---- publications ---- */

.pubs h2 {
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
}

.pubs h2:first-child { margin-top: 0; padding-top: 0; border-top: 0; }
.pubs li { margin-bottom: 0.75rem; font-size: 0.95rem; overflow-wrap: anywhere; word-break: normal; }
.pubs li::marker { color: var(--muted); font-size: 0.85em; }

/* ---- small screens ---- */

@media (max-width: 860px) {
  .site-header { flex-direction: column; align-items: stretch; gap: 0; }
  .brand { padding: 0.75rem 0 0.25rem; }
  .site-header nav {
    margin: 0 calc(-1 * var(--gutter));
    padding: 0 calc(var(--gutter) - 0.75rem);
    overflow-x: auto;
    scrollbar-width: none;
    -webkit-mask-image: linear-gradient(90deg, #000 85%, transparent);
    mask-image: linear-gradient(90deg, #000 85%, transparent);
  }
  .site-header nav::-webkit-scrollbar { display: none; }
  .site-header nav a { padding: 0.6rem 0.75rem 0.75rem; font-size: 0.92rem; }
}

@media (max-width: 760px) {
  .wrap { padding-top: 2.25rem; }
  .intro .wrap { padding-top: 2.5rem; }
  .intro p:not(.tagline) { font-size: 1rem; }
  .products, .two-col, .feature, .feature:nth-of-type(even) { grid-template-columns: 1fr; }
  .feature { gap: 1.1rem; }
  .feature:nth-of-type(even) img { order: 0; }
  .person { grid-template-columns: 1fr; gap: 1rem; padding: 1.25rem; }
  .person img { max-width: 9rem; }
}