:root {
  --paper: #f3f0e8;
  --paper-2: #e9e5da;
  --ink: #17211d;
  --muted: #68716c;
  --line: #cbc8bd;
  --acid: #d9ff42;
  --forest: #163f32;
  --blue: #2b66f6;
  --orange: #ff6a3d;
  --white: #fffdf7;
  --shadow: 0 24px 70px rgba(34, 38, 32, 0.12);
  --sans: Inter, Pretendard, "Apple SD Gothic Neo", "Noto Sans KR", system-ui, sans-serif;
  --serif: Iowan Old Style, "Noto Serif KR", "AppleMyungjo", serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; }
button, input { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }

.skip-link {
  position: fixed;
  z-index: 1000;
  left: 16px;
  top: 12px;
  padding: 10px 14px;
  background: var(--ink);
  color: #fff;
  transform: translateY(-160%);
}
.skip-link:focus { transform: none; }

.site-header {
  position: relative;
  z-index: 10;
  width: min(1440px, calc(100% - 48px));
  min-height: 82px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--line);
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
  font-size: 12px;
  font-weight: 850;
  letter-spacing: .035em;
  text-decoration: none;
  text-transform: uppercase;
}
.brand-slash { color: var(--orange); margin: 0 5px; }
.brand-mark { display: flex; align-items: end; gap: 3px; width: 23px; height: 20px; }
.brand-mark i { display: block; width: 5px; background: var(--ink); border-radius: 10px; transform: rotate(18deg); }
.brand-mark i:nth-child(1) { height: 11px; }
.brand-mark i:nth-child(2) { height: 19px; background: var(--orange); }
.brand-mark i:nth-child(3) { height: 14px; }
.site-header nav { display: flex; align-items: center; gap: 30px; }
.site-header nav a {
  font-size: 13px;
  font-weight: 750;
  text-decoration: none;
}
.site-header nav a:hover { text-decoration: underline; text-underline-offset: 5px; }

main { overflow: hidden; }
.hero {
  position: relative;
  width: min(1440px, calc(100% - 48px));
  min-height: 680px;
  margin: 0 auto;
  padding: 96px 0 90px;
  display: grid;
  grid-template-columns: minmax(0, 1.55fr) minmax(310px, .65fr);
  gap: 9vw;
  align-items: center;
}
.hero::before {
  content: "";
  position: absolute;
  z-index: -1;
  width: 420px;
  height: 420px;
  right: 13%;
  top: 5%;
  border: 1px solid #d8d4ca;
  border-radius: 50%;
}
.hero::after {
  content: "";
  position: absolute;
  z-index: -1;
  width: 140px;
  height: 140px;
  right: 3%;
  bottom: 11%;
  background: var(--acid);
  border-radius: 50%;
  filter: blur(.2px);
}
.eyebrow, .section-number, .index-kicker {
  margin: 0;
  font-size: 11px;
  font-weight: 900;
  letter-spacing: .16em;
  text-transform: uppercase;
}
.eyebrow { display: flex; align-items: center; gap: 12px; color: var(--forest); }
.eyebrow span { width: 36px; height: 4px; border-radius: 99px; background: var(--orange); }
.hero h1 {
  max-width: 980px;
  margin: 27px 0 28px;
  font-size: clamp(44px, 5.15vw, 76px);
  line-height: 1.11;
  letter-spacing: -.065em;
  font-weight: 830;
}
.hero h1 em {
  position: relative;
  z-index: 0;
  font-family: var(--serif);
  font-weight: 500;
  color: var(--forest);
}
.hero h1 em::after {
  content: "";
  position: absolute;
  z-index: -1;
  height: 12px;
  left: -3px;
  right: -8px;
  bottom: 3px;
  background: var(--acid);
  transform: rotate(-1deg);
}
.hero-lead {
  max-width: 690px;
  margin: 0;
  color: #56605a;
  font-size: 18px;
  line-height: 1.78;
  letter-spacing: -.015em;
}
.hero-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 36px; }
.button {
  min-height: 48px;
  padding: 0 20px;
  border: 1px solid var(--ink);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  font-size: 13px;
  font-weight: 850;
  text-decoration: none;
  transition: transform .16s ease, box-shadow .16s ease, background .16s ease;
}
.button:hover { transform: translateY(-2px); box-shadow: 4px 5px 0 var(--ink); }
.button-primary { background: var(--ink); color: #fff; }
.button-primary:hover { background: var(--forest); }
.button-ghost { background: transparent; }

.hero-index {
  position: relative;
  z-index: 1;
  padding: 31px;
  background: var(--forest);
  color: #fff;
  box-shadow: 16px 16px 0 rgba(22, 63, 50, .13);
  transform: rotate(1.2deg);
}
.index-kicker { color: #9bcab8; }
.hero-index dl { margin: 25px 0 26px; }
.hero-index dl div {
  min-height: 71px;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  border-bottom: 1px solid rgba(255, 255, 255, .16);
}
.hero-index dt { color: #c2d2ca; font-size: 13px; font-weight: 680; }
.hero-index dd { margin: 0; font-size: 42px; line-height: 1; font-weight: 380; letter-spacing: -.06em; }
.index-line { display: grid; grid-template-columns: 1.5fr .7fr 1fr .4fr; gap: 4px; height: 7px; }
.index-line span { background: var(--acid); }
.index-line span:nth-child(2) { background: #66d9ff; }
.index-line span:nth-child(3) { background: var(--orange); }
.index-line span:nth-child(4) { background: #fff; }
.index-note { margin: 18px 0 0; color: #aebfb7; font-size: 12px; line-height: 1.6; }

.catalog {
  padding: 102px max(24px, calc((100vw - 1440px) / 2));
  background: var(--white);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.section-heading {
  display: grid;
  grid-template-columns: 1fr minmax(260px, 450px);
  gap: 40px;
  align-items: end;
}
.section-number { margin-bottom: 18px; color: var(--orange); }
.section-heading h2, .about h2 {
  margin: 0;
  font-size: clamp(36px, 4.2vw, 60px);
  line-height: 1.05;
  letter-spacing: -.055em;
}
.section-heading > p {
  margin: 0 0 6px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}
.catalog-tools {
  margin: 54px 0 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.search-box {
  min-width: 310px;
  display: flex;
  align-items: center;
  gap: 10px;
  border-bottom: 1px solid var(--ink);
}
.search-box > span { font-size: 22px; transform: rotate(-12deg); }
.search-box input {
  width: 100%;
  height: 44px;
  padding: 0;
  border: 0;
  outline: 0;
  background: transparent;
  color: var(--ink);
  font-size: 13px;
}
.search-box input::placeholder { color: #9a9e98; }
.filters { display: flex; gap: 7px; flex-wrap: wrap; justify-content: flex-end; }
.filter {
  min-height: 37px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: 100px;
  background: transparent;
  color: var(--muted);
  font-size: 12px;
  font-weight: 760;
  cursor: pointer;
}
.filter:hover, .filter.active { border-color: var(--ink); background: var(--ink); color: #fff; }
.catalog-feedback {
  min-height: 28px;
  margin: -12px 0 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  color: var(--muted);
  font-size: 12px;
}
.catalog-feedback p { margin: 0; }
.search-reset {
  padding: 4px 0;
  border: 0;
  border-bottom: 1px solid currentColor;
  background: transparent;
  color: var(--ink);
  font: inherit;
  font-weight: 800;
  cursor: pointer;
}
.search-reset:hover { color: var(--blue); }
.course-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 20px; }
.course-card {
  --accent: var(--blue);
  position: relative;
  min-height: 450px;
  padding: 30px;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--paper);
  box-shadow: 0 0 0 transparent;
  transition: transform .22s ease, box-shadow .22s ease, border-color .22s ease;
}
.course-card:hover { transform: translateY(-5px); border-color: #a8aaa2; box-shadow: var(--shadow); }
.course-card::after {
  content: attr(data-number);
  position: absolute;
  right: -7px;
  top: -24px;
  color: color-mix(in srgb, var(--accent) 12%, transparent);
  font-size: 166px;
  line-height: 1;
  font-weight: 900;
  letter-spacing: -.1em;
}
.course-card[data-accent="acid"] { --accent: #8ba900; background: #f1f5dd; }
.course-card[data-accent="orange"] { --accent: var(--orange); background: #f7e9e1; }
.course-card[data-accent="teal"] { --accent: #0e7c7b; background: #e4f1ed; }
.course-top { position: relative; z-index: 1; display: flex; justify-content: space-between; gap: 20px; }
.course-type {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  color: var(--accent);
  font-size: 11px;
  font-weight: 900;
  letter-spacing: .11em;
  text-transform: uppercase;
}
.course-type::before { content: ""; width: 8px; height: 8px; border-radius: 50%; background: currentColor; }
.course-year { color: var(--muted); font-size: 11px; font-weight: 800; }
.course-card h3 {
  position: relative;
  z-index: 1;
  max-width: 590px;
  margin: 46px 0 14px;
  font-size: clamp(28px, 3vw, 42px);
  line-height: 1.14;
  letter-spacing: -.052em;
}
.course-description {
  position: relative;
  z-index: 1;
  max-width: 600px;
  margin: 0;
  color: #59635d;
  font-size: 14px;
  line-height: 1.72;
}
.course-tags { position: relative; z-index: 1; display: flex; flex-wrap: wrap; gap: 6px; margin-top: 23px; }
.course-tags span {
  padding: 6px 9px;
  border: 1px solid color-mix(in srgb, var(--accent) 35%, var(--line));
  background: rgba(255,255,255,.48);
  color: #4f5752;
  font-size: 10px;
  font-weight: 760;
}
.course-bottom {
  position: relative;
  z-index: 1;
  margin-top: auto;
  padding-top: 27px;
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 16px;
  border-top: 1px solid color-mix(in srgb, var(--accent) 25%, var(--line));
}
.course-stats { display: flex; gap: 18px; }
.course-stats span { display: grid; gap: 4px; color: var(--muted); font-size: 10px; font-weight: 750; }
.course-stats strong { color: var(--ink); font-size: 17px; letter-spacing: -.03em; }
.course-actions { display: flex; gap: 7px; }
.course-actions a, .course-actions button {
  min-height: 39px;
  padding: 0 13px;
  border: 1px solid var(--ink);
  background: transparent;
  color: var(--ink);
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-size: 11px;
  font-weight: 850;
  text-decoration: none;
  cursor: pointer;
}
.course-actions .open-course { background: var(--ink); color: #fff; }
.course-actions a:hover, .course-actions button:hover { background: var(--accent); border-color: var(--accent); color: #fff; }
.loading-card, .empty-state {
  grid-column: 1/-1;
  margin: 0;
  padding: 60px 24px;
  border: 1px dashed var(--line);
  color: var(--muted);
  text-align: center;
  font-size: 14px;
}

.learning-paths {
  padding: 105px max(24px, calc((100vw - 1440px) / 2));
  background: #18201c;
  color: #f6f3e9;
}
.section-heading.inverse > p { color: #9ca7a0; }
.path-list { margin: 64px 0 0; padding: 0; list-style: none; border-top: 1px solid #3b443f; }
.path-list li {
  min-height: 135px;
  display: grid;
  grid-template-columns: 75px 1fr auto;
  gap: 32px;
  align-items: center;
  border-bottom: 1px solid #3b443f;
  transition: padding .18s ease, color .18s ease;
}
.path-list li:hover { padding: 0 18px; color: var(--acid); }
.path-number { color: var(--orange); font-size: 12px; font-weight: 900; }
.path-list h3 { margin: 0 0 7px; font-size: 26px; letter-spacing: -.04em; }
.path-list p { margin: 0; color: #aab4ae; font-size: 13px; line-height: 1.65; }
.path-tag { color: #7f8983; font-size: 11px; font-weight: 750; }

.about {
  padding: 125px max(24px, calc((100vw - 1440px) / 2));
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 9vw;
  background: var(--acid);
}
.about .section-number { color: var(--forest); }
.about-copy { max-width: 620px; align-self: end; }
.about-copy p { margin: 0 0 22px; font-size: 16px; line-height: 1.8; letter-spacing: -.015em; }
.about-copy a { display: inline-flex; gap: 14px; margin-top: 15px; font-size: 13px; font-weight: 900; text-underline-offset: 5px; }
.site-footer {
  min-height: 88px;
  padding: 0 max(24px, calc((100vw - 1440px) / 2));
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  background: #18201c;
  color: #89938d;
  font-size: 11px;
  font-weight: 720;
  letter-spacing: .04em;
}
.site-footer .footer-contact {
  color: inherit;
  text-decoration: underline;
  text-underline-offset: 4px;
  transition: color .2s ease;
}
.site-footer .footer-contact:hover { color: #fff; }

.viewer {
  width: 100vw;
  max-width: none;
  height: 100vh;
  max-height: none;
  padding: 0;
  border: 0;
  background: #111814;
  color: #fff;
}
.viewer::backdrop { background: rgba(8, 12, 10, .86); }
.viewer-shell { width: 100%; height: 100%; display: grid; grid-template-rows: 68px 1fr; }
.viewer-bar {
  padding: 0 18px 0 23px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  border-bottom: 1px solid #344039;
}
.viewer-bar > div:first-child { min-width: 0; display: flex; align-items: center; gap: 14px; }
.viewer-bar span { color: #88a092; font-size: 10px; font-weight: 900; letter-spacing: .1em; }
.viewer-bar strong { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-size: 13px; }
.viewer-actions { display: flex; gap: 7px; flex: none; }
.viewer-actions a, .viewer-actions button {
  min-height: 36px;
  padding: 0 12px;
  border: 1px solid #46534c;
  background: #222c27;
  color: #fff;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 11px;
  font-weight: 800;
  text-decoration: none;
  cursor: pointer;
}
.viewer-actions button:hover, .viewer-actions a:hover { border-color: var(--acid); color: var(--acid); }
.viewer iframe { width: 100%; height: 100%; border: 0; background: #0b0f0d; }

.visually-hidden {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0,0,0,0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}

@media (max-width: 980px) {
  .hero { grid-template-columns: 1fr; gap: 60px; }
  .hero-index { max-width: 520px; }
  .course-grid { grid-template-columns: 1fr; }
  .course-card { min-height: 420px; }
  .section-heading { grid-template-columns: 1fr; }
  .catalog-tools { align-items: stretch; flex-direction: column; }
  .search-box { min-width: 0; width: 100%; }
  .catalog-feedback { align-items: flex-start; flex-direction: column; gap: 8px; }
  .filters { justify-content: flex-start; }
  .about { grid-template-columns: 1fr; gap: 50px; }
}

@media (max-width: 680px) {
  .site-header { width: calc(100% - 32px); min-height: 70px; }
  .site-header nav { gap: 14px; }
  .site-header nav a:nth-child(2) { display: none; }
  .brand { font-size: 10px; }
  .hero { width: calc(100% - 32px); min-height: auto; padding: 72px 0; }
  .hero h1 { font-size: 43px; }
  .hero-lead { font-size: 16px; }
  .hero-index { padding: 24px; margin-right: 8px; }
  .hero::before { right: -55%; }
  .hero::after { width: 90px; height: 90px; bottom: 18%; right: -3%; }
  .catalog, .learning-paths, .about { padding-top: 78px; padding-bottom: 78px; }
  .section-heading h2, .about h2 { font-size: 40px; }
  .course-card { min-height: 480px; padding: 23px; }
  .course-card::after { font-size: 130px; }
  .course-card h3 { margin-top: 45px; font-size: 32px; }
  .course-bottom { align-items: stretch; flex-direction: column; }
  .course-actions a, .course-actions button { flex: 1; justify-content: center; }
  .path-list li { grid-template-columns: 38px 1fr; gap: 16px; padding: 26px 0; }
  .path-list li:hover { padding: 26px 8px; }
  .path-tag { grid-column: 2; }
  .site-footer { padding-top: 24px; padding-bottom: 24px; align-items: flex-start; flex-direction: column; }
  .viewer-bar { padding: 0 10px; }
  .viewer-bar > div:first-child > span, #viewer-external { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; }
}