@charset "utf-8";
/* ==========================================================================
   LinkedClass · Unified Design System (base)
   온라인강의 토큰 기준 + 4개 랜딩 공통 셸
   ========================================================================== */

/* ---------- 1. Design Tokens ---------- */
:root {
  /* surface */
  --background: #ffffff;
  --surface: #ffffff;
  --card: #ffffff;
  --muted: #f5f6f8;
  --secondary: #f4f5f9;
  --border: #e6e8ec;
  --border-soft: rgba(31, 36, 46, .08);

  /* text */
  --foreground: #1f242e;
  --muted-foreground: #6a7280;
  --fg: var(--foreground);
  --muted-fg: var(--muted-foreground);

  /* brand */
  --primary: #2f5cf5;
  --primary-strong: #2149d6;
  --primary-soft: #6a8cff;
  --primary-foreground: #ffffff;
  --accent: #eaf0ff;
  --accent-foreground: #2149d6;

  /* alias (원본 소스 호환) */
  --brand: var(--primary);
  --brand-strong: var(--primary-strong);
  --brand-light: var(--primary-soft);
  --brand-foreground: var(--primary-foreground);
  --brand-fg: var(--primary-foreground);

  /* dark surface */
  --navy: #1c2236;
  --navy-foreground: #eef0f7;
  --navy-fg: var(--navy-foreground);
  --cream: #f5efe4;

  /* shape */
  --radius-xs: 10px;
  --radius-sm: 14px;
  --radius: 18px;
  --radius-lg: 26px;
  --radius-pill: 999px;
  --maxw: 1180px;

  /* elevation */
  --shadow-sm: 0 1px 2px rgba(16, 20, 32, .05), 0 1px 3px rgba(16, 20, 32, .04);
  --shadow-md: 0 4px 12px -4px rgba(16, 20, 32, .08), 0 16px 40px -20px rgba(16, 20, 32, .22);
  --shadow-lg: 0 8px 24px -8px rgba(16, 20, 32, .10), 0 32px 72px -28px rgba(16, 20, 32, .34);
  --shadow-brand: 0 10px 28px -10px color-mix(in srgb, var(--primary) 55%, transparent);

  /* type */
  --font-sans: "Pretendard Variable", Pretendard, "Noto Sans KR", -apple-system,
    BlinkMacSystemFont, system-ui, "Apple SD Gothic Neo", sans-serif;
  --font-mono: "JetBrains Mono", "Roboto Mono", ui-monospace, SFMono-Regular, monospace;

  /* motion */
  --ease: cubic-bezier(.22, .61, .36, 1);
  --ease-spring: cubic-bezier(.34, 1.4, .5, 1);
  --row-global: 68px;
  --row-seg: 60px;
  --header-h: 68px;
}

/* ---------- 2. Reset ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: 84px;
  -webkit-text-size-adjust: 100%;
  background: var(--background);
  overflow-x: clip;          /* sticky 헤더를 깨지 않으면서 가로 스크롤 차단 */
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; }
}

body {
  font-family: var(--font-sans);
  font-weight: 400;
  color: var(--foreground);
  background: var(--background);
  line-height: 1.65;
  letter-spacing: -0.011em;
  word-break: keep-all;
  overflow-wrap: anywhere;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  overflow-x: clip;
}
body.no-scroll { overflow-y: clip; }   /* hidden 은 sticky 헤더를 깨뜨림 */

img, svg, video { display: block; max-width: 100%; }
img { height: auto; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button, input, select, textarea { font: inherit; color: inherit; }
button { background: none; border: 0; cursor: pointer; }
strong, b { font-weight: 700; }

h1, h2, h3, h4, h5 {
  line-height: 1.22;
  letter-spacing: -0.028em;
  font-weight: 800;
  text-wrap: balance;
}
h1 { font-size: clamp(2rem, 1.15rem + 3.6vw, 3.75rem); letter-spacing: -0.036em; }
h2 { font-size: clamp(1.6rem, 1.05rem + 2.3vw, 2.75rem); }
h3 { font-size: clamp(1.1rem, .95rem + .6vw, 1.375rem); }
p { text-wrap: pretty; }

::selection { background: color-mix(in srgb, var(--primary) 22%, transparent); }
:focus-visible { outline: 2px solid var(--primary); outline-offset: 3px; border-radius: 6px; }

.visually-hidden, .sr-only {
  position: absolute; width: 1px; height: 1px; overflow: hidden;
  clip: rect(0 0 0 0); clip-path: inset(50%); white-space: nowrap;
}
.skip-link {
  position: fixed; top: 8px; left: 8px; z-index: 200; transform: translateY(-200%);
  padding: 10px 18px; border-radius: var(--radius-pill);
  background: var(--primary); color: #fff; font-weight: 700; font-size: 14px;
  transition: transform .2s var(--ease);
}
.skip-link:focus { transform: none; }

/* ---------- 3. Layout ---------- */
.container, .wrap {
  width: 100%; max-width: var(--maxw); margin-inline: auto; padding-inline: 20px;
}
@media (min-width: 768px) { .container, .wrap { padding-inline: 32px; } }
.wrap-narrow { max-width: 840px; }
.wrap-mid { max-width: 980px; }

.section, .sec { position: relative; padding-block: clamp(64px, 8vw, 120px); }
.section--soft, .section.soft, .section.bg-secondary, .sec.soft { background: var(--muted); }
.section--dark, .section.dark, .section.bg-navy, .sec.dark {
  background: var(--navy); color: var(--navy-foreground);
}
.section--dark p, .section.dark p, .section.bg-navy p, .sec.dark p {
  color: color-mix(in srgb, var(--navy-foreground) 78%, transparent);
}

/* 섹션 사이 미세한 구분선 */
.section + .section:not([class*="dark"]):not([class*="soft"]):not([class*="secondary"])::before {
  content: ""; position: absolute; inset-inline: 0; top: 0; height: 1px;
  background: linear-gradient(90deg, transparent, var(--border), transparent);
}

.eyebrow {
  display: inline-block; margin-bottom: 14px;
  font-size: 12.5px; font-weight: 800; letter-spacing: .18em;
  text-transform: uppercase; color: var(--primary);
  font-family: var(--font-mono);
}
.section--dark .eyebrow, .section.dark .eyebrow,
.section.bg-navy .eyebrow, .sec.dark .eyebrow { color: var(--primary-soft); }
.eyebrow--ko { letter-spacing: -0.01em; text-transform: none; font-family: var(--font-sans); font-size: 13.5px; }
.text-primary { color: var(--primary); }

/* ---------- 4. Buttons ---------- */
.btn {
  position: relative; display: inline-flex; align-items: center; justify-content: center;
  gap: 8px; border-radius: var(--radius-pill); border: 1px solid transparent;
  font-weight: 700; letter-spacing: -0.015em; white-space: nowrap; cursor: pointer;
  padding: 13px 26px; font-size: 15.5px;
  transition: transform .28s var(--ease-spring), box-shadow .28s var(--ease),
              background .2s var(--ease), border-color .2s var(--ease), color .2s var(--ease);
}
.btn svg { width: 1.08em; height: 1.08em; flex: none; transition: transform .28s var(--ease-spring); }
.btn:hover svg { transform: translateX(4px); }
.btn:active { transform: translateY(0) scale(.985); }
.btn-lg { padding: 16px 34px; font-size: 17px; }
.btn-md { padding: 11px 22px; font-size: 15px; }
.btn-sm { padding: 9px 18px; font-size: 14px; }
.btn-block { width: 100%; }

.btn-primary {
  background: linear-gradient(180deg,
    color-mix(in srgb, var(--primary) 92%, #fff) 0%, var(--primary) 100%);
  color: var(--primary-foreground);
  box-shadow: var(--shadow-brand);
}
.btn-primary:hover {
  background: var(--primary-strong);
  transform: translateY(-2px);
  box-shadow: 0 16px 36px -12px color-mix(in srgb, var(--primary) 62%, transparent);
}

.btn-secondary, .btn-ghost, .btn-outline {
  background: var(--card); color: var(--foreground); border-color: var(--border);
  box-shadow: var(--shadow-sm);
}
.btn-secondary:hover, .btn-ghost:hover, .btn-outline:hover {
  border-color: color-mix(in srgb, var(--primary) 42%, transparent);
  background: var(--accent); color: var(--accent-foreground);
  transform: translateY(-2px);
}

.btn-on-primary, .btn-light {
  background: #fff; color: var(--primary); box-shadow: var(--shadow-md);
}
.btn-on-primary:hover, .btn-light:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); }

.btn-ghost-light {
  background: rgba(255, 255, 255, .07); color: #fff;
  border-color: rgba(255, 255, 255, .28); backdrop-filter: blur(8px);
}
.btn-ghost-light:hover { background: rgba(255, 255, 255, .16); transform: translateY(-2px); }

/* ---------- 5. Header (2단: 공통 / 분야별) ---------- */
.site-header {
  position: sticky; top: 0; z-index: 90;
  background: color-mix(in srgb, var(--background) 86%, transparent);
  backdrop-filter: saturate(180%) blur(18px);
  -webkit-backdrop-filter: saturate(180%) blur(18px);
  border-bottom: 1px solid transparent;
  transition: box-shadow .35s var(--ease), border-color .35s var(--ease),
              background .35s var(--ease);
}
.site-header.is-stuck {
  border-bottom-color: var(--border);
  box-shadow: 0 4px 24px -12px rgba(16, 20, 32, .28);
}

/* 1단 — 전 분야 공통 */
.header-row--global {
  height: var(--row-global); overflow: hidden;
  transition: height .34s var(--ease), opacity .22s var(--ease);
}
.header-row--global .header-inner {
  height: var(--row-global); display: flex; align-items: center; gap: 18px;
}

/* 2단 — 분야별 */
.header-row--seg {
  display: none; height: var(--row-seg);
  transition: height .34s var(--ease), border-color .3s var(--ease);
}
.header-row--seg::before {
  content: ""; display: block; height: 1px; margin-inline: 20px;
  background: var(--border);
  transition: opacity .3s var(--ease);
}
.header-inner--seg {
  height: calc(var(--row-seg) - 1px); display: flex; align-items: center; gap: 14px;
}

/* 축소 시 2단에 노출되는 컴팩트 로고 */
.seg-brand { display: none; align-items: center; gap: 8px; flex: none;
  font-weight: 800; font-size: 16.5px; letter-spacing: -0.03em;
  opacity: 0; width: 0; overflow: hidden; white-space: nowrap;
  transition: opacity .3s var(--ease), width .34s var(--ease); }
.seg-brand .brand-mark { width: 28px; height: 28px; border-radius: 9px; }
.seg-brand .brand-mark svg { width: 16px; height: 16px; }

.brand {
  display: inline-flex; align-items: center; gap: 9px;
  font-weight: 800; font-size: 19px; letter-spacing: -0.03em; flex: none;
}
.brand-mark {
  display: grid; place-items: center; width: 32px; height: 32px;
  border-radius: 10px; color: #fff;
  background: linear-gradient(135deg, var(--primary), color-mix(in srgb, var(--primary) 55%, #7b5cff));
  box-shadow: var(--shadow-brand);
}
.brand-mark svg { width: 18px; height: 18px; }

/* 공통 메뉴 */
.nav-global { display: none; margin-inline-start: auto; align-items: center; gap: 2px; }
.nav-global a {
  padding: 8px 12px; border-radius: var(--radius-pill);
  font-size: 14.5px; font-weight: 600; color: var(--muted-foreground);
  transition: color .2s var(--ease), background .2s var(--ease);
}
.nav-global a:hover { color: var(--foreground); background: var(--muted, #f5f6f8); }

.auth-link {
  display: none; flex: none; padding: 8px 16px;
  border: 1px solid var(--border); border-radius: var(--radius-pill);
  font-size: 14.5px; font-weight: 700; color: var(--foreground);
  transition: border-color .2s var(--ease), color .2s var(--ease);
}
.auth-link:hover { border-color: color-mix(in srgb, var(--primary) 45%, transparent); color: var(--primary); }

/* 분야별 메뉴 */
.nav-seg { display: none; align-items: center; gap: 2px; flex: 1; }
.nav-seg a {
  position: relative; padding: 7px 12px; border-radius: var(--radius-pill);
  font-size: 14.5px; font-weight: 600; color: var(--muted-foreground);
  transition: color .2s var(--ease), background .2s var(--ease);
}
.nav-seg a:hover, .nav-seg a.is-active {
  color: var(--primary); background: var(--accent);
}

/* 분야 전환 드롭다운 */
.seg-switch { position: relative; display: none; flex: none; }
.seg-switch__btn {
  display: inline-flex; align-items: center; gap: 7px;
  padding: 7px 14px; border-radius: var(--radius-pill);
  border: 1px solid var(--border); background: var(--card);
  font-size: 14px; font-weight: 700; color: var(--foreground);
  transition: border-color .2s var(--ease), background .2s var(--ease);
}
.seg-switch__btn:hover { border-color: color-mix(in srgb, var(--primary) 40%, transparent); background: var(--accent); }
.seg-switch__btn .caret { width: 14px; height: 14px; transition: transform .25s var(--ease); }
.seg-switch.is-open .seg-switch__btn .caret { transform: rotate(180deg); }
.seg-switch__menu {
  position: absolute; top: calc(100% + 10px); left: 0; width: 268px; padding: 8px;
  border-radius: var(--radius); border: 1px solid var(--border);
  background: var(--card); box-shadow: var(--shadow-lg);
  display: none; z-index: 10;
}
.seg-switch__menu a {
  display: flex; align-items: center; gap: 11px; padding: 10px 11px;
  border-radius: var(--radius-xs); transition: background .18s var(--ease);
}
.seg-switch__menu a:hover { background: var(--muted, #f5f6f8); }
.seg-switch__menu a.is-current { background: var(--accent); }
.seg-switch__menu .ico {
  display: grid; place-items: center; width: 34px; height: 34px; flex: none;
  border-radius: 10px; background: var(--muted, #f5f6f8); color: var(--primary);
}
.seg-switch__menu a.is-current .ico { background: var(--primary); color: #fff; }
.seg-switch__menu .ico svg { width: 17px; height: 17px; }
.seg-switch__menu b { display: block; font-size: 14.5px; font-weight: 700; }
.seg-switch__menu span span { display: block; font-size: 12.5px; color: var(--muted-foreground); }

.header-cta { display: none; flex: none; margin-inline-start: auto; }
.header-cta--global { margin-inline-start: 0; }

/* 햄버거 / 닫기 — flex 로 3선 정렬 (grid 사용 시 행 높이가 어긋남) */
.header-burger {
  margin-inline-start: auto; flex: none;
  display: inline-flex; align-items: center; justify-content: center;
  width: 42px; height: 42px; border-radius: 12px;
  border: 1px solid var(--border); background: var(--card); color: var(--foreground);
  transition: border-color .2s var(--ease), background .2s var(--ease);
}
.header-burger:hover { border-color: color-mix(in srgb, var(--primary) 40%, transparent); }
.burger-bars {
  position: relative; display: block; width: 18px; height: 14px;
}
.burger-bars i {
  position: absolute; left: 0; width: 100%; height: 2px; border-radius: 2px;
  background: currentColor;
  transition: transform .3s var(--ease), opacity .18s var(--ease), top .3s var(--ease);
}
.burger-bars i:nth-child(1) { top: 0; }
.burger-bars i:nth-child(2) { top: 6px; }
.burger-bars i:nth-child(3) { top: 12px; }
.header-burger.is-open .burger-bars i:nth-child(1) { top: 6px; transform: rotate(45deg); }
.header-burger.is-open .burger-bars i:nth-child(2) { opacity: 0; }
.header-burger.is-open .burger-bars i:nth-child(3) { top: 6px; transform: rotate(-45deg); }

/* 모바일 패널 */
.nav-mobile {
  display: none; position: absolute; inset-inline: 0; top: 100%; z-index: 89;
  max-height: calc(100dvh - var(--header-h)); overflow-y: auto;
  padding: 8px 20px 28px;
  background: var(--background); border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-lg);
}
.nav-mobile a.m-link {
  display: block; padding: 12px 4px; font-size: 16px; font-weight: 600;
  border-bottom: 1px solid var(--border-soft);
}
.nav-mobile .m-title {
  margin: 22px 0 6px; font-size: 12px; font-weight: 800; letter-spacing: 0;
  color: var(--muted-foreground);
}
.nav-mobile .m-title:first-child { margin-top: 10px; }
.nav-mobile .m-seg {
  display: flex; align-items: center; gap: 10px; padding: 11px 12px;
  border: 1px solid var(--border); border-radius: var(--radius-xs);
  margin-bottom: 7px; font-size: 15px; font-weight: 700;
}
.nav-mobile .m-seg.is-current { border-color: var(--primary); color: var(--primary); background: var(--accent); }
.nav-mobile .m-seg svg { width: 17px; height: 17px; flex: none; }
.nav-mobile .btn { margin-top: 10px; }
.nav-mobile .m-auth { margin-top: 20px; }

@media (min-width: 1024px) {
  :root { --header-h: 129px; }
  body.seg-hub { --header-h: 68px; }
  .nav-global, .auth-link, .nav-seg, .seg-switch, .header-cta { display: flex; }
  .header-row--seg { display: block; }
  .seg-brand { display: inline-flex; }
  .header-burger { display: none; }
  .nav-mobile { display: none !important; }

  /* 스크롤하면 1단은 접히고 2단만 남아 고정 */
  .site-header.is-condensed .header-row--global {
    height: 0; opacity: 0; pointer-events: none;
  }
  .site-header.is-condensed .header-row--seg { height: 58px; }
  .site-header.is-condensed .header-row--seg::before { opacity: 0; }
  .site-header.is-condensed .header-inner--seg { height: 58px; }
  .site-header.is-condensed .seg-brand { opacity: 1; width: 170px; }
  .seg-brand::after {
    content: ""; width: 1px; height: 18px; margin-inline: 12px 0;
    background: var(--border);
  }

  /* 허브는 2단이 없으므로 접지 않음 */
  body.seg-hub .site-header.is-condensed .header-row--global,
  body.seg-page .site-header.is-condensed .header-row--global {
    height: var(--row-global); opacity: 1; pointer-events: auto;
  }
}

/* ---------- 6. Scroll progress ---------- */
.scroll-progress {
  position: fixed; top: 0; left: 0; z-index: 95; height: 2.5px; width: 0;
  background: linear-gradient(90deg, var(--primary), color-mix(in srgb, var(--primary) 45%, #7b5cff));
  transition: width .1s linear;
}

/* ---------- 7. Reveal ---------- */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
.reveal.is-in { opacity: 1; transform: none; }
.reveal[data-delay="1"] { transition-delay: .08s; }
.reveal[data-delay="2"] { transition-delay: .16s; }
.reveal[data-delay="3"] { transition-delay: .24s; }
.reveal[data-delay="4"] { transition-delay: .32s; }
@media (prefers-reduced-motion: reduce) { .reveal { opacity: 1; transform: none; } }

/* ---------- 8. Footer ---------- */
.site-footer { padding-block: clamp(56px, 6vw, 88px) 40px; border-top: 1px solid var(--border); background: var(--background); }
.footer-head { text-align: center; margin-bottom: 30px; }
.footer-head h2 { font-size: clamp(1.15rem, .95rem + .8vw, 1.5rem); }
.footer-head p.lead { margin-top: 8px; color: var(--muted-foreground); font-size: 15px; }

.seg-cards { display: grid; gap: 12px; grid-template-columns: 1fr; }
@media (min-width: 640px) { .seg-cards { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .seg-cards { grid-template-columns: repeat(4, 1fr); } }
.seg-card {
  display: flex; align-items: center; gap: 12px; padding: 16px;
  border: 1px solid var(--border); border-radius: var(--radius); background: var(--card);
  transition: transform .3s var(--ease-spring), box-shadow .3s var(--ease), border-color .2s var(--ease);
}
.seg-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: color-mix(in srgb, var(--primary) 34%, transparent); }
.seg-card.is-current { border-color: var(--primary); background: var(--accent); }
.seg-card .ico { display: grid; place-items: center; width: 40px; height: 40px; flex: none; border-radius: 12px; background: var(--muted); color: var(--primary); }
.seg-card.is-current .ico { background: var(--primary); color: #fff; }
.seg-card .ico svg { width: 19px; height: 19px; }
.seg-card b { display: block; font-size: 15px; font-weight: 700; }
.seg-card span { display: block; font-size: 12.5px; line-height: 1.45; color: var(--muted-foreground); }
.seg-card .arrow { margin-inline-start: auto; color: var(--muted-foreground); transition: transform .3s var(--ease-spring); }
.seg-card .arrow svg { width: 16px; height: 16px; }
.seg-card:hover .arrow { transform: translate(3px, -3px); color: var(--primary); }

.footer-bottom {
  margin-top: 40px; padding-top: 26px; border-top: 1px solid var(--border);
  display: flex; flex-direction: column; align-items: center; gap: 16px; text-align: center;
}
.footer-bottom nav { display: flex; flex-wrap: wrap; justify-content: center; gap: 6px 20px; }
.footer-bottom nav a { font-size: 14.5px; color: var(--muted-foreground); transition: color .2s var(--ease); }
.footer-bottom nav a:hover { color: var(--primary); }
.footer-copy { font-size: 13.5px; color: var(--muted-foreground); }
.footer-biz {
  margin-top: 22px; padding-top: 20px; border-top: 1px solid var(--border-soft);
  font-size: 12.5px; line-height: 1.9; color: var(--muted-foreground);
}
.footer-biz b { font-weight: 700; color: var(--foreground); }
.footer-biz {
  margin-top: 22px; padding-top: 20px; border-top: 1px solid var(--border-soft);
  font-size: 12.5px; line-height: 1.9; color: var(--muted-foreground);
}
.footer-biz b { font-weight: 700; color: color-mix(in srgb, var(--foreground) 72%, transparent); }
@media (min-width: 768px) {
  .footer-bottom { flex-direction: row; justify-content: space-between; text-align: start; }
}

/* ---------- 9. Sticky CTA (mobile) ---------- */
.sticky-cta {
  position: fixed; inset-inline: 0; bottom: 0; z-index: 80;
  padding: 12px 16px calc(12px + env(safe-area-inset-bottom));
  background: color-mix(in srgb, var(--background) 86%, transparent);
  backdrop-filter: saturate(180%) blur(16px);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  border-top: 1px solid var(--border-soft);
  transform: translateY(120%); transition: transform .38s var(--ease);
}
.sticky-cta.is-shown { transform: none; }
.sticky-cta .btn { width: 100%; }
@media (min-width: 1024px) { .sticky-cta { display: none; } }

/* ---------- 10. Back to top ---------- */
.to-top {
  position: fixed; right: 20px; bottom: 88px; z-index: 78;
  width: 44px; height: 44px; display: grid; place-items: center;
  border-radius: 50%; border: 1px solid var(--border);
  background: var(--card); color: var(--foreground); box-shadow: var(--shadow-md);
  opacity: 0; visibility: hidden; transform: translateY(10px);
  transition: opacity .3s var(--ease), transform .3s var(--ease), visibility .3s;
}
.to-top.is-shown { opacity: 1; visibility: visible; transform: none; }
.to-top:hover { color: var(--primary); border-color: color-mix(in srgb, var(--primary) 40%, transparent); }
.to-top svg { width: 18px; height: 18px; }
@media (min-width: 1024px) { .to-top { bottom: 24px; } }

/* ---------- 11. Plugin skin ---------- */
/* magnific popup */
.mfp-bg { background: #0d1119; opacity: .93; }
.mfp-figure::after { box-shadow: var(--shadow-lg); border-radius: var(--radius); }
.mfp-img { border-radius: var(--radius); }
img.zoomable { cursor: zoom-in; }