:root {
  --ink: #111c2f;
  --muted: #5f6b7c;
  --line: #dce4ee;
  --paper: #f4f7fb;
  --white: #ffffff;
  --navy: #102442;
  --blue: #2367d1;
  --sky: #dcecff;
  --mint: #b8f1df;
  --lime: #ddf78d;
  --orange: #ffbd75;
  --shadow: 0 18px 60px rgba(17, 28, 47, .10);
  --radius-xl: 30px;
  --radius-lg: 22px;
  --radius-md: 15px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: Pretendard, "Noto Sans KR", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.65;
  word-break: keep-all;
}
a { color: inherit; text-decoration: none; }
button, input, select { font: inherit; }
button { cursor: pointer; }
.site-shell { width: min(1180px, calc(100% - 40px)); margin: 0 auto; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 1px solid rgba(220, 228, 238, .85);
  background: rgba(244, 247, 251, .92);
  backdrop-filter: blur(18px);
}
.header-row { min-height: 76px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand-lockup { display: inline-flex; align-items: center; gap: 12px; font-weight: 900; letter-spacing: -.04em; }
.brand-mark {
  width: 38px; height: 38px; display: grid; place-items: center;
  border-radius: 13px; background: var(--navy); color: white; font-size: 16px;
  box-shadow: inset 0 0 0 1px rgba(255,255,255,.12);
}
.brand-text { font-size: 21px; }
.main-nav { display: flex; align-items: center; gap: 6px; }
.main-nav a { padding: 10px 13px; border-radius: 10px; color: #405069; font-weight: 700; font-size: 14px; }
.main-nav a:hover, .main-nav a.active { background: white; color: var(--blue); box-shadow: 0 5px 20px rgba(17,28,47,.06); }
.header-cta { padding: 11px 16px; border-radius: 12px; color: white; background: var(--blue); font-weight: 800; font-size: 14px; }

.hero {
  position: relative; overflow: hidden; padding: 78px 0 54px;
  background:
    radial-gradient(circle at 84% 15%, rgba(184,241,223,.72), transparent 24%),
    radial-gradient(circle at 62% 90%, rgba(220,236,255,.82), transparent 30%),
    linear-gradient(180deg, #f8fbff 0%, var(--paper) 100%);
}
.hero::after {
  content: ""; position: absolute; right: -120px; top: 80px; width: 420px; height: 420px;
  border-radius: 50%; border: 1px solid rgba(35,103,209,.15); box-shadow: 0 0 0 60px rgba(35,103,209,.025), 0 0 0 120px rgba(35,103,209,.018);
}
.hero-grid { position: relative; z-index: 1; display: grid; grid-template-columns: .88fr 1.12fr; gap: 54px; align-items: center; }
.eyebrow { display: inline-flex; align-items: center; gap: 8px; margin-bottom: 18px; color: var(--blue); font-size: 13px; font-weight: 900; letter-spacing: .08em; text-transform: uppercase; }
.eyebrow::before { content: ""; width: 28px; height: 2px; background: currentColor; }
.hero h1 { margin: 0; font-size: clamp(42px, 5.2vw, 72px); line-height: 1.08; letter-spacing: -.065em; }
.hero h1 span { color: var(--blue); }
.hero-copy > p { margin: 22px 0 0; color: var(--muted); font-size: 18px; max-width: 560px; }
.hero-points { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 26px; }
.hero-points span { padding: 8px 11px; border: 1px solid #d8e4f3; border-radius: 999px; background: rgba(255,255,255,.76); color: #405069; font-size: 13px; font-weight: 700; }

.calculator {
  overflow: hidden; border: 1px solid rgba(218,227,239,.9); border-radius: var(--radius-xl);
  background: rgba(255,255,255,.94); box-shadow: var(--shadow);
}
.calc-head { padding: 22px 24px 18px; border-bottom: 1px solid var(--line); }
.calc-head strong { display: block; font-size: 18px; letter-spacing: -.02em; }
.calc-head p { margin: 3px 0 0; color: var(--muted); font-size: 13px; }
.calc-tabs { display: grid; grid-template-columns: repeat(3,1fr); gap: 7px; margin-top: 17px; padding: 6px; border-radius: 14px; background: #eef3f8; }
.calc-tab { border: 0; border-radius: 10px; padding: 10px 8px; background: transparent; color: #627087; font-weight: 800; font-size: 13px; }
.calc-tab.active { background: white; color: var(--blue); box-shadow: 0 3px 12px rgba(17,28,47,.08); }
.calc-panel { display: none; padding: 24px; }
.calc-panel.active { display: block; }
.field-grid { display: grid; grid-template-columns: 1.3fr .7fr; gap: 12px; }
.field-grid.three { grid-template-columns: repeat(3,1fr); }
.field { display: grid; gap: 7px; }
.field label { font-size: 12px; color: #536178; font-weight: 800; }
.field input, .field select { width: 100%; min-height: 49px; border: 1px solid #d7e0eb; border-radius: 12px; padding: 0 13px; background: white; color: var(--ink); outline: 0; }
.field input:focus, .field select:focus { border-color: var(--blue); box-shadow: 0 0 0 3px rgba(35,103,209,.1); }
.calc-result { margin-top: 17px; padding: 20px; border-radius: 17px; color: white; background: var(--navy); }
.calc-result small { color: #b9c8db; font-weight: 700; }
.calc-result strong { display: block; margin-top: 3px; font-size: 31px; letter-spacing: -.04em; }
.result-breakdown { display: grid; grid-template-columns: repeat(3,1fr); gap: 8px; margin-top: 14px; }
.result-breakdown span { padding: 9px; border-radius: 10px; background: rgba(255,255,255,.08); font-size: 11px; color: #d7e0eb; }
.result-breakdown b { display: block; color: white; font-size: 13px; }
.calc-source { display: flex; justify-content: space-between; gap: 12px; margin-top: 13px; color: #77849a; font-size: 11px; }

.content-section { padding: 70px 0; }
.content-section.white { background: white; }
.section-top { display: flex; align-items: end; justify-content: space-between; gap: 24px; margin-bottom: 28px; }
.section-top h2 { margin: 0; font-size: clamp(28px,3vw,40px); letter-spacing: -.045em; line-height: 1.2; }
.section-top p { margin: 8px 0 0; color: var(--muted); }
.section-link { color: var(--blue); font-weight: 900; font-size: 14px; white-space: nowrap; }

.use-cases { display: grid; grid-template-columns: repeat(3,1fr); gap: 18px; }
.use-card { position: relative; overflow: hidden; min-height: 250px; padding: 28px; border-radius: var(--radius-lg); background: white; border: 1px solid var(--line); }
.use-card:nth-child(1) { background: #12284a; color: white; border-color: #12284a; }
.use-card:nth-child(2) { background: #e7f3ff; }
.use-card:nth-child(3) { background: #eefadc; }
.use-number { display: inline-grid; place-items: center; width: 34px; height: 34px; border-radius: 50%; background: rgba(255,255,255,.85); color: var(--navy); font-size: 12px; font-weight: 900; }
.use-card h3 { margin: 28px 0 8px; font-size: 22px; letter-spacing: -.03em; }
.use-card p { margin: 0; color: inherit; opacity: .72; font-size: 14px; }
.use-card a { position: absolute; left: 28px; bottom: 26px; font-weight: 900; font-size: 14px; }

.editorial-grid { display: grid; grid-template-columns: 1.15fr .85fr; gap: 18px; }
.feature-story { padding: 36px; border-radius: var(--radius-xl); background: var(--navy); color: white; }
.story-kicker { color: var(--mint); font-size: 12px; font-weight: 900; letter-spacing: .08em; }
.feature-story h3 { margin: 18px 0 14px; max-width: 660px; font-size: clamp(28px,3.5vw,45px); line-height: 1.18; letter-spacing: -.045em; }
.feature-story p { color: #cbd7e7; max-width: 680px; }
.story-meta { margin-top: 28px; padding-top: 18px; border-top: 1px solid rgba(255,255,255,.12); display: flex; justify-content: space-between; color: #9fb0c6; font-size: 12px; }
.story-list { display: grid; gap: 12px; }
.story-item { display: block; padding: 22px; border-radius: 18px; background: white; border: 1px solid var(--line); transition: transform .2s ease, box-shadow .2s ease; }
.story-item:hover { transform: translateY(-2px); box-shadow: 0 13px 36px rgba(17,28,47,.08); }
.story-item small { color: var(--blue); font-weight: 900; }
.story-item strong { display: block; margin-top: 6px; font-size: 17px; letter-spacing: -.02em; }
.story-item span { display: block; margin-top: 4px; color: var(--muted); font-size: 13px; }

.method-grid { display: grid; grid-template-columns: .8fr 1.2fr; gap: 22px; align-items: stretch; }
.method-intro { padding: 34px; border-radius: var(--radius-xl); background: #dcecff; }
.method-intro h2 { margin: 0; font-size: 34px; letter-spacing: -.04em; }
.method-intro p { color: #485b75; }
.method-list { display: grid; grid-template-columns: repeat(2,1fr); gap: 12px; }
.method-item { padding: 22px; border-radius: 18px; background: white; border: 1px solid var(--line); }
.method-item b { display: block; margin-bottom: 6px; }
.method-item p { margin: 0; color: var(--muted); font-size: 13px; }

.site-footer { margin-top: 30px; padding: 54px 0 30px; color: #ced9e8; background: #0c192c; }
.footer-grid { display: grid; grid-template-columns: 1.4fr repeat(3, .7fr); gap: 34px; }
.footer-grid h3 { margin: 0; color: white; }
.footer-grid h4 { margin: 0 0 12px; color: white; font-size: 13px; }
.footer-grid p, .footer-grid a { display: block; margin: 7px 0; color: #9eafc6; font-size: 13px; }
.footer-bottom { margin-top: 36px; padding-top: 20px; border-top: 1px solid rgba(255,255,255,.1); color: #7f91aa; font-size: 12px; }

.reading{max-width:820px;padding:48px 0 70px}.reading .eyebrow{display:flex;margin-top:28px}.reading h1{font-size:clamp(30px,5vw,48px);line-height:1.25;letter-spacing:-.04em}.reading-lead{font-size:19px;color:var(--muted)}.reading-meta{font-size:13px;color:var(--muted);border-bottom:1px solid var(--line);padding-bottom:24px}.reading article{font-size:17px;line-height:1.95}.reading h2{font-size:24px;line-height:1.4;margin-top:42px}.reading article a{text-decoration:underline;color:var(--blue)}.table-wrap{overflow-x:auto}.reading table{border-collapse:collapse;width:100%;font-size:14px;background:white}.reading caption{text-align:left;color:var(--muted);padding:12px 0}.reading th,.reading td{text-align:left;padding:14px;border-bottom:1px solid var(--line)}.reading th{background:var(--sky)}.reading-note{margin-top:32px;padding:20px;background:var(--sky);border-radius:16px;font-size:14px}
.mobile-menu { display: none; border: 0; background: white; border-radius: 10px; width: 42px; height: 42px; color: var(--ink); }

@media (max-width: 900px) {
  .main-nav { display: none; position: absolute; left: 20px; right: 20px; top: 68px; padding: 12px; border-radius: 18px; background: white; box-shadow: var(--shadow); }
  .main-nav.open { display: grid; }
  .header-cta { display: none; }
  .mobile-menu { display: block; }
  .hero { padding-top: 52px; }
  .hero-grid, .editorial-grid, .method-grid { grid-template-columns: 1fr; }
  .hero-copy { text-align: center; }
  .hero-copy > p { margin-left: auto; margin-right: auto; }
  .hero-points { justify-content: center; }
  .use-cases { grid-template-columns: 1fr; }
  .use-card { min-height: 220px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 620px) {
  .site-shell { width: min(100% - 24px, 1180px); }
  .header-row { min-height: 66px; }
  .hero { padding: 38px 0 34px; }
  .hero h1 { font-size: 41px; }
  .hero-copy > p { font-size: 16px; }
  .calculator { border-radius: 22px; }
  .calc-head, .calc-panel { padding: 18px; }
  .field-grid, .field-grid.three { grid-template-columns: 1fr; }
  .result-breakdown { grid-template-columns: 1fr; }
  .content-section { padding: 52px 0; }
  .section-top { align-items: start; flex-direction: column; }
  .method-list, .footer-grid { grid-template-columns: 1fr; }
  .calc-source { flex-direction: column; }
}