:root {
  --bg: #f7faf7;
  --surface: #ffffff;
  --muted: #eef5f0;
  --text: #15221b;
  --subtext: #5a6a60;
  --line: #dce7df;
  --green: #1f6f4a;
  --green-dark: #174d37;
  --bluegreen: #256f73;
  --accent: #d7efe2;
  --shadow: 0 18px 50px rgba(21, 34, 27, 0.08);
  --radius: 24px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Pretendard", "Noto Sans KR", "Apple SD Gothic Neo", system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
}

a { color: inherit; text-decoration: none; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 6vw;
  background: rgba(247, 250, 247, 0.9);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--line);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 900;
  letter-spacing: -0.02em;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: 14px;
  background: var(--green);
  color: white;
  font-size: 15px;
}

.brand-text { font-size: 21px; }

.nav {
  display: flex;
  align-items: center;
  gap: 22px;
  font-size: 15px;
  color: var(--subtext);
}

.nav a:hover { color: var(--green); }

.nav-cta {
  padding: 10px 16px;
  background: var(--green);
  color: white !important;
  border-radius: 999px;
}

.nav-toggle {
  display: none;
  border: 0;
  background: transparent;
  font-size: 26px;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.18fr) minmax(320px, 0.82fr);
  gap: 56px;
  align-items: center;
  padding: 96px 6vw 72px;
}

.eyebrow {
  margin: 0 0 14px;
  color: var(--green);
  font-size: 13px;
  font-weight: 900;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1, h2, h3 { line-height: 1.2; letter-spacing: -0.045em; }

h1 { margin: 0; font-size: clamp(42px, 6vw, 76px); }
h2 { font-size: clamp(30px, 4vw, 46px); margin: 0 0 16px; }
h3 { margin: 0 0 10px; font-size: 22px; }

.hero-text {
  max-width: 760px;
  margin: 26px 0 0;
  font-size: 20px;
  color: var(--subtext);
}

.hero-actions {
  display: flex;
  gap: 12px;
  margin-top: 34px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 13px 20px;
  border-radius: 999px;
  font-weight: 900;
  border: 1px solid transparent;
  cursor: pointer;
}

.btn.primary { background: var(--green); color: white; }
.btn.secondary { background: white; color: var(--green-dark); border-color: var(--line); }

.hero-panel {
  min-height: 430px;
  border-radius: 36px;
  background:
    radial-gradient(circle at 30% 20%, rgba(215, 239, 226, 0.95), transparent 35%),
    linear-gradient(145deg, #ffffff, #edf7f1);
  box-shadow: var(--shadow);
  padding: 36px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  border: 1px solid var(--line);
}

.metric-num {
  display: block;
  font-size: 96px;
  font-weight: 900;
  color: var(--green);
  line-height: 1;
}

.metric-label { font-weight: 900; color: var(--subtext); }

.system-map {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.system-map span {
  padding: 22px 18px;
  border-radius: 18px;
  background: white;
  border: 1px solid var(--line);
  font-weight: 900;
  text-align: center;
}

.section,
.page-hero,
.split-section,
.tool-section,
.contact-section,
.article {
  padding: 76px 6vw;
}

.page-hero { background: linear-gradient(180deg, #ffffff, var(--bg)); }
.page-hero h1 { max-width: 1000px; font-size: clamp(38px, 5vw, 62px); }

.page-hero p:not(.eyebrow) {
  max-width: 840px;
  font-size: 20px;
  color: var(--subtext);
}

.section-header {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 30px;
  margin-bottom: 34px;
}

.section-lead {
  max-width: 460px;
  color: var(--subtext);
}

.cards { display: grid; gap: 22px; }
.grid-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }

.card,
.contact-card,
.tool-card,
.result-card,
.project-detail-card,
.research-card,
.publication-item {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.card { padding: 28px; }
.card p { color: var(--subtext); }

.icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 54px;
  height: 54px;
  margin-bottom: 18px;
  border-radius: 18px;
  background: var(--accent);
  color: var(--green-dark);
  font-weight: 900;
  font-size: 13px;
}

.subtitle, .tagline {
  margin: 0 0 12px;
  color: var(--green);
  font-weight: 900;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 18px;
}

.tags span {
  display: inline-flex;
  padding: 7px 10px;
  border-radius: 999px;
  background: var(--muted);
  color: var(--green-dark);
  font-size: 13px;
  font-weight: 800;
}

.muted { background: var(--muted); }

.split-section {
  display: grid;
  grid-template-columns: 0.85fr 1.15fr;
  gap: 70px;
  align-items: start;
  background: var(--surface);
}

.text-block {
  font-size: 20px;
  color: var(--subtext);
}

.text-link {
  display: inline-flex;
  margin-top: 12px;
  color: var(--green);
  font-weight: 900;
}

.timeline {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}

.timeline-item {
  padding: 34px;
  border-left: 4px solid var(--green);
  background: white;
  border-radius: 18px;
  box-shadow: var(--shadow);
}

.timeline-item span { font-weight: 900; color: var(--green); }

.research-list, .project-list, .publication-list { display: grid; gap: 22px; }

.research-card {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 40px;
  padding: 34px;
}

.research-card ul { margin: 0; padding-left: 22px; color: var(--subtext); }

.project-detail-card { padding: 34px; }
.project-meta { color: var(--green); font-weight: 900; margin-bottom: 10px; }

.project-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
  margin-top: 20px;
}

.project-grid h4 { margin: 0 0 8px; }
.project-grid p { margin: 0; color: var(--subtext); }

.filter-bar {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 26px;
}

.filter-bar a {
  padding: 10px 14px;
  border-radius: 999px;
  background: white;
  border: 1px solid var(--line);
  color: var(--subtext);
  font-weight: 900;
}

.filter-bar a.active { background: var(--green); color: white; }

.publication-item {
  display: grid;
  grid-template-columns: 160px 1fr;
  gap: 28px;
  padding: 30px;
}

.pub-type {
  width: max-content;
  height: max-content;
  padding: 9px 13px;
  background: var(--green);
  color: white;
  border-radius: 999px;
  font-weight: 900;
}

.article {
  max-width: 900px;
  margin: 0 auto;
  background: var(--bg);
}

.article.wide { max-width: 1080px; }

.article h1 { font-size: clamp(38px, 5vw, 60px); }
.article .lead { font-size: 22px; color: var(--subtext); }
.article p { font-size: 19px; }

.article-section { margin: 42px 0; }

.article-note {
  margin: 34px 0;
  padding: 24px;
  background: white;
  border-radius: 18px;
  border: 1px solid var(--line);
}

.metric-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin: 32px 0;
}

.mini-metric {
  padding: 20px;
  background: white;
  border: 1px solid var(--line);
  border-radius: 18px;
  box-shadow: var(--shadow);
}

.mini-metric span { display: block; color: var(--subtext); }
.mini-metric strong { font-size: 26px; color: var(--green-dark); }

.tool-section {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 24px;
}

.tool-card {
  display: grid;
  grid-template-columns: 0.85fr 1.15fr;
  gap: 40px;
  padding: 36px;
}

.tool-form, .contact-form { display: grid; gap: 16px; }

label {
  display: grid;
  gap: 8px;
  color: var(--subtext);
  font-weight: 900;
}

input, select, textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 13px 14px;
  font: inherit;
  color: var(--text);
  background: white;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.result-card { padding: 28px; }

.result-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
}

.result-metric {
  background: var(--muted);
  padding: 18px;
  border-radius: 16px;
}

.result-metric strong {
  display: block;
  font-size: 26px;
  color: var(--green-dark);
}

.hidden { display: none; }

.contact-section {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  gap: 28px;
}

.contact-card, .contact-form {
  padding: 34px;
  background: white;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 30px;
  padding: 40px 6vw;
  background: var(--text);
  color: white;
}

.site-footer p, .footer-links { color: rgba(255,255,255,0.7); }
.footer-links { display: grid; gap: 4px; text-align: right; }

@media (max-width: 1040px) {
  .hero, .split-section, .tool-card, .contact-section, .research-card {
    grid-template-columns: 1fr;
  }

  .grid-4, .grid-3, .timeline, .project-grid, .result-grid, .metric-row {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 760px) {
  .nav-toggle { display: block; }

  .nav {
    display: none;
    position: absolute;
    top: 78px;
    left: 4vw;
    right: 4vw;
    flex-direction: column;
    align-items: stretch;
    padding: 20px;
    background: white;
    border: 1px solid var(--line);
    border-radius: 22px;
    box-shadow: var(--shadow);
  }

  .nav.open { display: flex; }

  .hero, .section, .page-hero, .split-section, .tool-section, .contact-section, .article {
    padding-left: 5vw;
    padding-right: 5vw;
  }

  .hero { padding-top: 56px; }

  .grid-4, .grid-3, .timeline, .project-grid, .result-grid, .publication-item, .form-row, .metric-row {
    grid-template-columns: 1fr;
  }

  .section-header, .site-footer { display: grid; }
  .footer-links { text-align: left; }

  h1 { font-size: 42px; }
}