:root {
  color-scheme: light;
  --ink: #1b273d;
  --muted: #536278;
  --line: #dceaf0;
  --brand: #01b7f3;
  --brand-dark: #076f9f;
  --brand-soft: #f1fbfe;
  --prose-width: 800px;
  --media-width: var(--prose-width);
  font-family: "Sora", "Avenir Next", "Segoe UI", system-ui, -apple-system,
    BlinkMacSystemFont, "Apple SD Gothic Neo", "Noto Sans KR", "Noto Sans CJK KR",
    Arial, sans-serif;
  scroll-behavior: smooth;
}

* { box-sizing: border-box; }

html { overflow-x: clip; }

body {
  margin: 0;
  min-width: 320px;
  color: var(--ink);
  background: #fff;
  font-size: 18px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

button, input { font: inherit; }

a { color: var(--brand-dark); text-underline-offset: 3px; }
a:hover { color: #055a80; }
a:focus-visible, button:focus-visible, summary:focus-visible {
  outline: 3px solid #38b6e8;
  outline-offset: 4px;
  border-radius: 3px;
}

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

.skip-link {
  position: absolute;
  z-index: 10;
  top: -100px;
  left: 16px;
  padding: 10px 15px;
  border-radius: 8px;
  color: #fff;
  background: var(--brand-dark);
}
.skip-link:focus { top: 12px; }

.site-header {
  position: relative;
  z-index: 2;
  background: #fff;
  border-bottom: 1px solid #e1eef3;
}

.header-inner {
  width: min(100% - 48px, 1200px);
  min-height: 76px;
  margin-inline: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand { display: inline-flex; align-items: center; flex: none; line-height: 1; }
.brand img { width: auto; height: 31px; max-width: 160px; object-fit: contain; }
.header-nav { display: flex; align-items: center; justify-content: flex-end; flex-wrap: wrap; gap: 12px 30px; }
.header-nav a {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  color: #25364e;
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  white-space: nowrap;
}
.header-nav a:hover { color: var(--brand-dark); }
.header-nav a.header-product-entry {
  padding: 0 20px;
  border: 1px solid #b3dded;
  border-radius: 9px;
  color: var(--brand-dark);
  background: var(--brand-soft);
}

.hero {
  padding: 85px 24px 90px;
  background: linear-gradient(120deg, #fbfdff 0%, #eef9fd 45%, #e5f6fa 100%);
  border-bottom: 1px solid #dceef4;
  text-align: center;
}
.hero-inner { width: min(100%, 990px); margin-inline: auto; }
.hero h1 {
  max-width: 900px;
  margin: 0 auto;
  font-size: clamp(34px, 4.2vw, 48px);
  line-height: 1.22;
  letter-spacing: -0.045em;
  font-weight: 700;
  text-wrap: balance;
}

.article { padding: 72px 24px 112px; }
.article-body { min-width: 0; }
.toc-sidebar { display: none; }
.prose { width: min(100%, var(--prose-width)); margin-inline: auto; }
.article p { margin-top: 0; margin-bottom: 22px; }
.article p:last-child { margin-bottom: 0; }
.article strong { font-weight: 700; color: #1b283d; }
.article ul, .article ol { padding-left: 1.45em; margin: 20px 0 24px; }
.article li { padding-left: .15em; margin-bottom: 9px; }
.intro { color: #364760; }

.toc {
  width: min(100%, var(--prose-width));
  margin: 36px auto 0;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #f8fcfe;
  font-size: 15px;
  line-height: 1.5;
}
.toc summary {
  position: relative;
  padding: 18px 46px 18px 22px;
  cursor: pointer;
  font-weight: 700;
  list-style: none;
}
.toc summary::-webkit-details-marker { display: none; }
.toc summary span[aria-hidden="true"] { display: none; }
.toc summary::after {
  content: "";
  position: absolute;
  top: calc(50% - 6px);
  right: 23px;
  width: 9px;
  height: 9px;
  border-right: 2px solid #65758e;
  border-bottom: 2px solid #65758e;
  transform: rotate(45deg);
  transition: transform .18s ease;
}
.toc[open] summary::after { transform: translateY(4px) rotate(225deg); }
.toc nav, .toc ul, .toc ol { margin: 0; }
.toc nav { padding: 0 22px 19px; }
.toc ul, .toc ol { padding: 0 0 0 1.3em; }
.toc li { margin: 7px 0; }
.toc a { color: #3d5672; text-decoration: none; }
.toc a:hover { color: var(--brand-dark); text-decoration: underline; }

.step-section, .article-section {
  margin-top: 78px;
  scroll-margin-top: 28px;
}
.article-section:first-of-type { margin-top: 72px; }
.article h2 {
  width: min(100%, var(--prose-width));
  margin: 0 auto 25px;
  font-size: clamp(27px, 3vw, 34px);
  line-height: 1.34;
  letter-spacing: -0.035em;
  font-weight: 700;
  text-wrap: pretty;
}
.article h3 {
  width: min(100%, var(--prose-width));
  margin: 36px auto 16px;
  font-size: 22px;
  line-height: 1.4;
  letter-spacing: -.025em;
  font-weight: 700;
}

.wide-media, .article-image {
  width: min(100%, var(--media-width));
  margin: 28px auto 32px;
}
.article-image .image-trigger {
  display: block;
  width: 100%;
  max-width: 100%;
  margin-inline: auto;
  padding: 0;
  border: 1px solid #d4e7ee;
  border-radius: 13px;
  overflow: hidden;
  background: #f8fcfe;
  box-shadow: 0 4px 16px rgba(16, 75, 107, .04);
  cursor: zoom-in;
  transition: box-shadow .18s ease, transform .18s ease;
}
.article-image .image-trigger:hover {
  box-shadow: 0 6px 20px rgba(16, 75, 107, .08);
  transform: translateY(-2px);
}
.article-image img { width: 100%; max-width: 100%; height: auto; object-fit: contain; }
.article-image figcaption {
  margin-top: 11px;
  color: #718096;
  font-size: 13px;
  line-height: 1.55;
  text-align: center;
}

.primary-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 54px;
  padding: 14px 24px;
  border-radius: 10px;
  color: #fff;
  background: var(--brand-dark);
  box-shadow: 0 8px 20px rgba(7, 111, 159, .18);
  font-size: 16px;
  font-weight: 700;
  line-height: 1.45;
  text-align: center;
  text-decoration: none;
  transition: background-color .18s ease, transform .18s ease;
}
.primary-cta:hover { color: #fff; background: #055a80; transform: translateY(-2px); }
.primary-cta:active { transform: translateY(0); }

.faq { border-top: 1px solid var(--line); padding-top: 64px; }
.faq-list { width: min(100%, var(--prose-width)); margin: 30px auto 0; border-top: 1px solid var(--line); }
.faq-item { border-bottom: 1px solid var(--line); }
.faq-item summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 22px;
  min-height: 76px;
  padding: 18px 4px;
  cursor: pointer;
  list-style: none;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item .faq-question { width: auto; margin: 0; font-size: 20px; line-height: 1.45; }
.faq-item summary:hover .faq-question, .faq-item[open] .faq-question { color: var(--brand-dark); }
.faq-icon {
  position: relative;
  flex: none;
  width: 32px;
  height: 32px;
  border: 1px solid #b3dded;
  border-radius: 50%;
  background: var(--brand-soft);
}
.faq-icon::before, .faq-icon::after {
  content: "";
  position: absolute;
  left: 9px;
  top: 14px;
  width: 12px;
  height: 2px;
  border-radius: 2px;
  background: var(--brand-dark);
}
.faq-icon::after { transform: rotate(90deg); }
.faq-item[open] .faq-icon::after { opacity: 0; }
.faq-answer { padding: 0 48px 28px 4px; color: #364760; }
.faq-answer .prose { width: 100%; }

.site-footer { border-top: 1px solid var(--line); background: #f8fcfe; }
.footer-inner {
  width: min(100% - 48px, 1200px);
  min-height: 110px;
  margin-inline: auto;
  padding: 32px 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 18px 34px;
  color: #68778c;
  font-size: 13px;
  line-height: 1.5;
}
.site-footer nav { display: flex; flex-wrap: wrap; gap: 12px 24px; }
.site-footer a { color: #52647d; text-decoration: none; }
.site-footer a:hover { color: var(--brand-dark); text-decoration: underline; }
.site-footer .footer-brand { color: #24334a; font-size: 19px; font-weight: 700; }

.image-lightbox {
  position: fixed;
  inset: 0;
  width: min(96vw, 1600px);
  max-width: none;
  max-height: calc(100dvh - 32px);
  margin: auto;
  padding: 48px 18px 20px;
  border: 1px solid #d7e0ed;
  border-radius: 14px;
  overflow: auto;
  background: #fff;
  box-shadow: 0 24px 90px rgba(16, 28, 46, .35);
  text-align: center;
  overscroll-behavior: contain;
}
.image-lightbox::backdrop { background: rgba(10, 19, 32, .78); }
.lightbox-close {
  position: sticky;
  z-index: 1;
  top: -40px;
  float: right;
  display: inline-grid;
  place-items: center;
  width: 44px;
  height: 44px;
  margin-top: -40px;
  padding: 0;
  border: 0;
  border-radius: 50%;
  background: transparent;
  color: #28374d;
  cursor: pointer;
  line-height: 1;
}
.lightbox-close span {
  display: inline-grid;
  place-items: center;
  width: 28px;
  height: 28px;
  border: 1px solid #dce3ec;
  border-radius: 50%;
  background: #fff;
  font-size: 19px;
}
.lightbox-close:hover span { background: #edf8fc; }
.lightbox-image {
  clear: both;
  width: auto;
  height: auto;
  max-width: 100%;
  max-height: calc(100dvh - 128px);
  margin: 0 auto;
  object-fit: contain;
  touch-action: pinch-zoom;
}
.lightbox-caption { margin: 13px 0 0; color: #617089; font-size: 13px; line-height: 1.45; }

@media (max-width: 767px) {
  body { font-size: 16px; line-height: 1.72; }
  .header-inner { width: min(100% - 32px, 1200px); min-height: 66px; gap: 14px; }
  .brand img { height: 27px; max-width: 130px; }
  .header-nav { gap: 8px 14px; }
  .header-nav a { font-size: 12px; min-height: 40px; }
  .header-nav a.header-product-entry { padding-inline: 11px; }
  .hero { padding: 66px 20px 72px; }
  .hero h1 { font-size: clamp(30px, 7.8vw, 36px); line-height: 1.25; }
  .article { padding: 48px 20px 80px; }
  .article p { margin-bottom: 18px; }
  .step-section, .article-section { margin-top: 60px; }
  .article h2 { margin-bottom: 19px; font-size: 27px; }
  .article h3 { font-size: 19px; margin-top: 28px; }
  .wide-media, .article-image { margin: 24px auto 30px; }
  .article-image .image-trigger { border-radius: 9px; }
  .toc { margin-top: 28px; font-size: 14px; }
  .faq { padding-top: 48px; }
  .faq-list { margin-top: 24px; }
  .faq-item summary { gap: 15px; min-height: 68px; padding: 17px 2px; }
  .faq-item .faq-question { font-size: 17px; }
  .faq-icon { width: 29px; height: 29px; }
  .faq-icon::before, .faq-icon::after { left: 8px; top: 13px; }
  .faq-answer { padding: 0 36px 22px 2px; }
  .footer-inner { width: min(100% - 40px, 1200px); min-height: auto; padding: 30px 0; }
  .image-lightbox { width: calc(100vw - 16px); max-height: calc(100dvh - 16px); padding: 46px 8px 16px; }
  .lightbox-image { max-height: calc(100dvh - 115px); }
}

@media (max-width: 390px) {
  .header-nav { gap: 8px; }
  .header-nav a { font-size: 11px; }
  .header-nav a.header-product-entry { padding-inline: 9px; }
  .hero { padding-inline: 18px; }
  .article { padding-inline: 18px; }
}

@media (min-width: 1180px) {
  .article {
    display: grid;
    grid-template-columns: 240px minmax(0, 800px);
    gap: 48px;
    width: min(calc(100% - 48px), 1088px);
    margin-inline: auto;
    padding: 72px 0 112px;
    align-items: start;
  }
  .article-body > .toc { display: none; }
  .toc-sidebar {
    display: block;
    position: sticky;
    top: 24px;
    max-height: calc(100dvh - 48px);
    overflow-y: auto;
    scrollbar-width: thin;
  }
  .toc-sidebar h2 { width: auto; margin: 0 0 18px; font-size: 15px; line-height: 1.5; letter-spacing: 0; }
  .toc-sidebar ol { list-style: none; margin: 0; padding: 0; border-left: 1px solid var(--line); }
  .toc-sidebar li { margin: 0 0 6px; padding: 0; }
  .toc-sidebar a {
    display: block;
    padding: 10px 12px 10px 15px;
    margin-left: -1px;
    border-left: 2px solid transparent;
    color: #536278;
    font-size: 13px;
    line-height: 1.6;
    text-decoration: none;
    overflow-wrap: anywhere;
  }
  .toc-sidebar a:hover { color: var(--brand-dark); background: #f8fcfe; }
  .toc-sidebar a[aria-current="location"] { color: var(--brand-dark); border-left-color: var(--brand-dark); background: var(--brand-soft); font-weight: 600; }
}

@media (prefers-reduced-motion: reduce) {
  :root { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: .01ms !important; animation-duration: .01ms !important; }
}

.tutorial-list {padding-left: 26px; margin-top: 16px; margin-bottom: 24px;}
.tutorial-list li {padding-left: 4px; margin: 8px 0;}