:root {
  --bg: #f6f8fb;
  --card: #ffffff;
  --text: #111827;
  --muted: #687385;
  --line: #e7ebf1;
  --accent: #111827;
  --accent-soft: #edf2f8;
  --blue: #3167e3;
  --blue-soft: #eef4ff;
  --shadow: 0 14px 42px rgba(17, 24, 39, .06);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans KR", Arial, sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at 85% 0%, rgba(49, 103, 227, .07), transparent 30%),
    var(--bg);
  line-height: 1.65;
  letter-spacing: -.01em;
}

a { color: inherit; }
.wrap { width: min(1060px, calc(100% - 40px)); margin: 0 auto; }

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, .88);
  border-bottom: 1px solid rgba(231, 235, 241, .9);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}
.brand-row {
  min-height: 76px;
  display: flex;
  align-items: center;
  gap: 13px;
}
.brand-mark {
  width: 44px;
  height: 44px;
  border-radius: 13px;
  display: grid;
  place-items: center;
  background: var(--accent);
  color: #fff;
  font-size: 23px;
  font-weight: 800;
  box-shadow: 0 8px 20px rgba(17, 24, 39, .14);
}
.brand-copy { min-width: 0; }
.brand-row h1 { margin: 0; font-size: 20px; line-height: 1.25; letter-spacing: -.03em; }
.brand-row p { margin: 4px 0 0; color: var(--muted); font-size: 13px; line-height: 1.3; }

main { padding: 34px 0 64px; }
.card {
  background: rgba(255, 255, 255, .96);
  border: 1px solid var(--line);
  border-radius: 20px;
  box-shadow: var(--shadow);
}

.hero {
  position: relative;
  overflow: hidden;
  min-height: 290px;
  padding: 46px 48px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 220px;
  align-items: center;
  gap: 32px;
  background: linear-gradient(135deg, #111827 0%, #182438 66%, #213454 100%);
  border-color: transparent;
  color: #fff;
  box-shadow: 0 18px 50px rgba(17, 24, 39, .16);
}
.hero::after {
  content: "";
  position: absolute;
  width: 360px;
  height: 360px;
  border-radius: 50%;
  right: -140px;
  top: -175px;
  border: 1px solid rgba(255,255,255,.10);
  box-shadow: 0 0 0 54px rgba(255,255,255,.025), 0 0 0 108px rgba(255,255,255,.018);
}
.hero-copy { position: relative; z-index: 1; max-width: 690px; }
.badge {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 5px 10px;
  background: rgba(255,255,255,.11);
  border: 1px solid rgba(255,255,255,.14);
  border-radius: 999px;
  color: rgba(255,255,255,.88);
  font-size: 11px;
  font-weight: 750;
  letter-spacing: .06em;
  text-transform: uppercase;
}
h2 { margin: 0; font-size: 25px; line-height: 1.32; letter-spacing: -.045em; }
.hero h2 { margin: 13px 0 12px; max-width: 650px; font-size: clamp(30px, 4.2vw, 42px); line-height: 1.18; letter-spacing: -.055em; }
.hero p { max-width: 650px; margin: 0; color: rgba(255,255,255,.70); font-size: 15px; line-height: 1.75; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 25px; }
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 10px 15px;
  border: 1px solid rgba(255,255,255,.24);
  border-radius: 11px;
  color: rgba(255,255,255,.90);
  text-decoration: none;
  font-size: 14px;
  font-weight: 700;
  transition: transform .16s ease, background .16s ease, border-color .16s ease;
}
.btn:hover { transform: translateY(-1px); background: rgba(255,255,255,.08); }
.btn.primary { background: #fff; color: var(--accent); border-color: #fff; }
.btn.primary:hover { background: #f6f8fb; }
.hero-symbol {
  position: relative;
  z-index: 1;
  display: grid;
  place-items: center;
  justify-self: end;
  width: 174px;
  height: 174px;
  border-radius: 44px;
  border: 1px solid rgba(255,255,255,.13);
  background: linear-gradient(145deg, rgba(255,255,255,.12), rgba(255,255,255,.04));
  box-shadow: inset 0 1px 0 rgba(255,255,255,.08), 0 24px 50px rgba(0,0,0,.18);
  transform: rotate(4deg);
}
.hero-symbol::before {
  content: "B";
  font-size: 84px;
  line-height: 1;
  font-weight: 850;
  letter-spacing: -.08em;
  transform: rotate(-4deg) translateX(-4px);
}

.support-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
  margin-top: 14px;
}
.support-card {
  min-height: 220px;
  padding: 24px 22px;
  display: flex;
  flex-direction: column;
  transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease;
}
.support-card:hover {
  transform: translateY(-2px);
  border-color: #dce3ed;
  box-shadow: 0 16px 38px rgba(17,24,39,.08);
}
.icon {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  background: var(--blue-soft);
  font-size: 20px;
}
.support-copy { margin-top: auto; padding-top: 30px; }
h3 { margin: 0 0 8px; font-size: 18px; line-height: 1.35; letter-spacing: -.035em; }
.card p { margin: 0; color: #566171; }
.support-card p { font-size: 13.5px; line-height: 1.72; }

.content-grid {
  display: grid;
  grid-template-columns: 1.08fr .92fr;
  gap: 14px;
  margin-top: 14px;
  align-items: stretch;
}
.bottom-grid {
  display: grid;
  grid-template-columns: .8fr 1.2fr;
  gap: 14px;
  margin-top: 14px;
  align-items: stretch;
}
.steps, .faq, .contact, .privacy { padding: 30px; }
.section-heading {
  display: flex;
  align-items: center;
  gap: 11px;
  margin-bottom: 16px;
}
.section-heading::before {
  content: "";
  width: 5px;
  height: 22px;
  border-radius: 999px;
  background: var(--blue);
}

.steps ol { list-style: none; padding: 0; margin: 4px 0 0; }
.steps li {
  position: relative;
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 14px;
  padding: 14px 0;
}
.steps li + li { border-top: 1px solid var(--line); }
.steps li > span {
  width: 34px;
  height: 34px;
  border-radius: 11px;
  background: var(--accent);
  color: #fff;
  display: grid;
  place-items: center;
  font-size: 12px;
  font-weight: 800;
}
.steps strong { display: block; margin: 1px 0 2px; font-size: 14px; }
.steps p { font-size: 13.5px; line-height: 1.65; }

details { border-top: 1px solid var(--line); }
details:first-of-type { margin-top: 2px; }
summary {
  position: relative;
  cursor: pointer;
  list-style: none;
  padding: 17px 30px 17px 0;
  font-size: 14px;
  font-weight: 700;
  line-height: 1.5;
}
summary::-webkit-details-marker { display: none; }
summary::after {
  content: "+";
  position: absolute;
  right: 2px;
  top: 50%;
  transform: translateY(-50%);
  color: #788395;
  font-size: 20px;
  font-weight: 400;
}
details[open] summary::after { content: "−"; }
details p { padding: 0 28px 17px 0; font-size: 13.5px; line-height: 1.65; }

.contact, .privacy { min-height: 250px; }
.contact {
  display: flex;
  flex-direction: column;
}
.contact > p { font-size: 14px; line-height: 1.75; }
.contact .muted {
  margin-top: auto;
  padding-top: 22px;
  color: var(--muted);
  font-size: 13px;
}
.privacy > p { font-size: 13.5px; line-height: 1.72; }
.privacy ul {
  margin: 16px 0;
  padding: 15px 18px 15px 34px;
  border-radius: 13px;
  background: #f8fafc;
  color: #566171;
  font-size: 13px;
  line-height: 1.75;
}

footer { border-top: 1px solid var(--line); background: rgba(255,255,255,.88); }
.footer-row {
  min-height: 74px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  color: var(--muted);
  font-size: 12.5px;
}
.footer-row a { text-decoration: none; }
.footer-row a:hover { color: var(--text); }

@media (max-width: 900px) {
  .hero { grid-template-columns: minmax(0, 1fr) 150px; padding: 40px; }
  .hero-symbol { width: 136px; height: 136px; border-radius: 35px; }
  .hero-symbol::before { font-size: 66px; }
  .support-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .support-card { min-height: 205px; }
}

@media (max-width: 720px) {
  .wrap { width: min(100% - 24px, 1060px); }
  .topbar { position: static; }
  .brand-row { min-height: 68px; }
  main { padding: 18px 0 42px; }
  .hero {
    min-height: 0;
    padding: 30px 24px;
    grid-template-columns: 1fr;
  }
  .hero h2 { font-size: 29px; }
  .hero p { font-size: 14px; }
  .hero-symbol { display: none; }
  .support-grid { grid-template-columns: 1fr; gap: 10px; margin-top: 10px; }
  .support-card {
    min-height: 0;
    padding: 20px;
    display: grid;
    grid-template-columns: 42px minmax(0, 1fr);
    gap: 14px;
    align-items: start;
  }
  .support-copy { margin: 0; padding: 1px 0 0; }
  .content-grid, .bottom-grid { grid-template-columns: 1fr; gap: 10px; margin-top: 10px; }
  .steps, .faq, .contact, .privacy { padding: 23px 20px; }
  .contact, .privacy { min-height: 0; }
  .contact .muted { margin-top: 12px; padding-top: 0; }
  .section-heading { margin-bottom: 12px; }
  .section-heading h2 { font-size: 21px; }
  .footer-row { min-height: 68px; }
}

@media (max-width: 420px) {
  .brand-mark { width: 40px; height: 40px; border-radius: 12px; font-size: 21px; }
  .brand-row h1 { font-size: 18px; }
  .brand-row p { font-size: 12px; }
  .hero { border-radius: 18px; }
  .hero h2 { font-size: 27px; }
  .hero-actions { flex-direction: column; }
  .btn { width: 100%; }
  .card { border-radius: 17px; }
}