/* ==========================================================================
   D-Friends — one page site
   컬러는 전부 로고에서 뽑았다(오렌지·딥네이비·레드·스카이).
   섹션 리듬: 히어로(화이트) → About(다크) → 교육과정(화이트) →
              플랫폼(연회색) → 연혁(다크) → 푸터(더 진한 다크)
   ========================================================================== */

:root {
  /* 브랜드 — 로고 실측 계열 */
  --orange:      #f5821f;
  --orange-dark: #e06f0d;
  /* 브랜드 오렌지(#f5821f)는 흰 배경에서 대비 2.59로 본문 글자에 쓸 수 없다.
     같은 색상환을 유지하면서 명도만 낮춘 «글자용 오렌지»를 따로 둔다.
     흰 배경 5.20 / 연회색 밴드 4.85 — 두 배경 모두에서 AA 를 넘긴다. */
  --orange-ink:  #af5210;
  --amber:       #fdb913;
  --red:         #d63a4a;
  --crimson:     #a81e3c;
  --sky:         #1b9cd8;
  --navy:        #123a5f;
  --navy-deep:   #0c2740;
  --navy-ink:    #08192a;

  /* 라이트 */
  --bg:        #ffffff;
  --bg-soft:   #f5f7fa;
  --text:      #16212e;
  --text-mute: #5a6675;
  --text-faint:#6b7684;
  --border:    #e5e9ef;

  /* 다크 밴드 */
  --d-text:      #ffffff;
  --d-text-mute: #a9bdd2;
  --d-border:    rgba(255, 255, 255, .13);
  --d-card:      rgba(255, 255, 255, .05);

  --wrap:   1160px;
  --radius: 18px;
  --shadow: 0 1px 2px rgba(16, 33, 51, .04), 0 12px 32px rgba(16, 33, 51, .07);
  --shadow-lg: 0 2px 4px rgba(16, 33, 51, .05), 0 26px 60px rgba(16, 33, 51, .13);
  --ease: cubic-bezier(.22, .8, .3, 1);

  --header-h: 86px;
}

/* ── reset ─────────────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: var(--header-h); }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Pretendard Variable", Pretendard, -apple-system, BlinkMacSystemFont,
               system-ui, "Segoe UI", Roboto, "Helvetica Neue", "Apple SD Gothic Neo",
               "Noto Sans KR", sans-serif;
  font-size: 17px;
  line-height: 1.75;
  letter-spacing: -.015em;
  word-break: keep-all;      /* 한글 줄바꿈은 어절 단위로 */
  overflow-wrap: break-word;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
h1, h2, h3, h4 { margin: 0; line-height: 1.32; letter-spacing: -.03em; font-weight: 700; }
p { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
svg { display: block; }

.wrap { width: 100%; max-width: var(--wrap); margin: 0 auto; padding: 0 24px; }

.skip {
  position: absolute; left: -9999px; top: 0; z-index: 200;
  background: var(--navy); color: #fff; padding: 12px 20px; border-radius: 0 0 10px 0;
}
.skip:focus { left: 0; }

:focus-visible { outline: 3px solid var(--orange); outline-offset: 3px; border-radius: 6px; }

/* ── buttons ───────────────────────────────────────────────────────────── */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  height: 54px; padding: 0 30px; border-radius: 999px;
  font-size: 16px; font-weight: 700; letter-spacing: -.02em; white-space: nowrap;
  transition: transform .22s var(--ease), box-shadow .22s var(--ease),
              background .22s var(--ease), color .22s var(--ease), border-color .22s var(--ease);
}
.btn-sm { height: 44px; padding: 0 20px; font-size: 15px; }  /* 44px = 터치 타깃 하한 */

.btn-primary {
  color: #fff;
  /* 밝은 앰버~오렌지 위의 흰 글자는 대비 2.59 로 AA 에 한참 못 미친다.
     같은 색상환에서 명도만 낮춘 «럿빛 오렌지»로 5.18~5.84 를 확보한다. */
  background: linear-gradient(135deg, #c2410c 0%, #b04a0b 55%, #a8480a 100%);
  box-shadow: 0 8px 22px rgba(168, 72, 10, .32);
}
.btn-primary:hover {
  transform: translateY(-2px);
  background: linear-gradient(135deg, #ab390a 0%, #9c4109 55%, #953f08 100%);
  box-shadow: 0 14px 32px rgba(168, 72, 10, .42);
}

.btn-ghost { color: var(--navy); border: 1.5px solid var(--border); background: #fff; }
.btn-ghost:hover { border-color: var(--navy); transform: translateY(-2px); }

/* ── header ────────────────────────────────────────────────────────────── */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255, 255, 255, .72);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid transparent;
  transition: background .25s var(--ease), border-color .25s var(--ease), box-shadow .25s var(--ease);
}
.site-header.scrolled {
  background: rgba(255, 255, 255, .92);
  border-bottom-color: var(--border);
  box-shadow: 0 6px 24px rgba(16, 33, 51, .05);
}
.header-inner { height: var(--header-h); display: flex; align-items: center; justify-content: space-between; gap: 20px; }

/* 브랜드 — 로고 마크 + 워드마크.
   dfriends02.png(마크+워드마크+태그라인 일체형)는 헤더 높이로 줄이면 태그라인이 뭉개진다.
   그래서 마크만 쓰고 워드마크는 활자로 다시 짠다. 크기를 키워도 선명하다. */
.brand { display: inline-flex; align-items: center; gap: 12px; }
.brand-mark {
  height: 42px; width: 42px; object-fit: contain; flex: none;
  transition: transform .3s var(--ease);
}
.brand:hover .brand-mark { transform: rotate(30deg); }
.brand-name {
  font-size: 23px; font-weight: 800; letter-spacing: .01em; line-height: 1;
  background: linear-gradient(100deg, var(--amber) 0%, var(--orange) 55%, #ef6b2a 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}

.nav { display: flex; align-items: center; gap: 26px; }
.nav > a:not(.btn) {
  font-size: 16px; font-weight: 600; color: var(--text-mute);
  position: relative; padding: 4px 0;
  transition: color .18s var(--ease);
}
.nav > a:not(.btn)::after {
  content: ""; position: absolute; left: 0; right: 100%; bottom: 0; height: 2px;
  background: var(--orange); border-radius: 2px;
  transition: right .28s var(--ease);
}
.nav > a:not(.btn):hover,
.nav > a:not(.btn).active { color: var(--navy); }
.nav > a:not(.btn):hover::after,
.nav > a:not(.btn).active::after { right: 0; }
.nav > a:not(.btn).active { font-weight: 700; }
.nav-cta { margin-left: 6px; }

.nav-toggle { display: none; width: 44px; height: 44px; padding: 11px 10px; flex-direction: column; justify-content: space-between; }
.nav-toggle span { display: block; height: 2px; width: 100%; background: var(--navy); border-radius: 2px; transition: transform .3s var(--ease), opacity .2s var(--ease); }
.nav-toggle.open span:nth-child(1) { transform: translateY(9px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-9px) rotate(-45deg); }

/* ── hero ──────────────────────────────────────────────────────────────── */
.hero {
  position: relative; overflow: hidden;
  padding: 108px 0 132px;
  min-height: calc(100vh - var(--header-h));
  display: flex; flex-direction: column; justify-content: center;
}
.hero-glow {
  position: absolute; inset: -30% -10% auto -10%; height: 120%;
  background:
    radial-gradient(46% 46% at 78% 22%, rgba(245, 130, 31, .18), transparent 68%),
    radial-gradient(40% 40% at 88% 62%, rgba(27, 156, 216, .16), transparent 70%),
    radial-gradient(34% 34% at 6% 8%, rgba(214, 58, 74, .10), transparent 70%);
  pointer-events: none;
}
/* 마크는 뷰포트가 아니라 «본문 칼럼»에 매단다.
   초광폭 화면에서 오른쪽 끝으로 떨어져 나가지 않게 하려는 것이다. */
.hero-mark-wrap {
  position: absolute; top: 0; bottom: 0; left: 0; right: 0;
  max-width: var(--wrap); margin: 0 auto; padding: 0 24px;
  pointer-events: none;
}
.hero-mark {
  position: absolute; right: -30px; top: 50%; transform: translateY(-50%);
  width: min(500px, 42vw); opacity: .15;
  animation: float 9s ease-in-out infinite;
}
@keyframes float {
  0%, 100% { transform: translateY(-50%) rotate(0deg); }
  50%      { transform: translateY(-54%) rotate(6deg); }
}
.hero-inner { position: relative; }

.eyebrow {
  font-size: 14px; font-weight: 700; letter-spacing: .18em; text-transform: uppercase;
  color: var(--orange-ink); margin-bottom: 22px;
}
.hero-title { font-size: clamp(38px, 6.4vw, 74px); font-weight: 800; letter-spacing: -.045em; line-height: 1.18; }
.grad {
  background: linear-gradient(105deg, var(--amber) 0%, var(--orange) 34%, var(--red) 68%, var(--crimson) 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero-sub { margin-top: 26px; font-size: clamp(17px, 2vw, 20px); color: var(--text-mute); font-weight: 500; }
.hero-sub strong { color: var(--text); font-weight: 700; }
.hero-actions { margin-top: 42px; display: flex; flex-wrap: wrap; gap: 12px; }

.chips { margin-top: 56px; display: flex; flex-wrap: wrap; gap: 8px; }
.chips li {
  font-size: 14px; font-weight: 600; color: var(--text-mute);
  padding: 7px 15px; border: 1px solid var(--border); border-radius: 999px;
  background: rgba(255, 255, 255, .7);
  transition: color .2s var(--ease), border-color .2s var(--ease), transform .2s var(--ease);
}
.chips li:hover { color: var(--orange-ink); border-color: rgba(245, 130, 31, .5); transform: translateY(-2px); }

.scroll-hint {
  position: absolute; left: 50%; bottom: 34px; transform: translateX(-50%);
  width: 26px; height: 42px; border: 2px solid var(--border); border-radius: 999px;
  display: flex; justify-content: center; padding-top: 8px;
}
.scroll-hint span { width: 4px; height: 8px; border-radius: 2px; background: var(--orange); animation: wheel 1.7s var(--ease) infinite; }
@keyframes wheel { 0% { opacity: 0; transform: translateY(-3px); } 40% { opacity: 1; } 100% { opacity: 0; transform: translateY(12px); } }

/* ── section 공통 ──────────────────────────────────────────────────────── */
.section { padding: 118px 0; }
.band-soft { background: var(--bg-soft); }
.band-dark {
  background:
    radial-gradient(58% 70% at 88% 0%, rgba(27, 156, 216, .20), transparent 62%),
    radial-gradient(48% 60% at 4% 100%, rgba(245, 130, 31, .16), transparent 64%),
    linear-gradient(168deg, var(--navy) 0%, var(--navy-deep) 100%);
  color: var(--d-text);
}
.label {
  font-size: 13px; font-weight: 700; letter-spacing: .2em; text-transform: uppercase;
  color: var(--orange-ink); margin-bottom: 16px;
}
/* 다크 밴드 위에서는 글자용 오렌지가 오히려 어두워진다. 로고의 앰버로 바꾼다(5.33). */
.band-dark .label { color: var(--amber); }
.section-title { font-size: clamp(28px, 4vw, 44px); font-weight: 800; letter-spacing: -.04em; }
.section-lead { margin-top: 20px; max-width: 720px; font-size: 17px; color: var(--text-mute); font-weight: 500; }
.band-dark .section-lead { color: var(--d-text-mute); }
.band-dark .section-lead strong { color: #fff; font-weight: 700; }

/* ── About : 강점 3 ────────────────────────────────────────────────────── */
.strengths { margin-top: 62px; display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.strength {
  padding: 34px 30px 32px;
  background: var(--d-card); border: 1px solid var(--d-border); border-radius: var(--radius);
  transition: transform .3s var(--ease), background .3s var(--ease), border-color .3s var(--ease);
}
.strength:hover { transform: translateY(-5px); background: rgba(255, 255, 255, .09); border-color: rgba(255, 255, 255, .24); }
.ico {
  width: 50px; height: 50px; border-radius: 14px; margin-bottom: 22px;
  display: grid; place-items: center; color: #fff;
}
.ico svg { width: 25px; height: 25px; }
.ico-sky    { background: linear-gradient(135deg, #3fb6ea, var(--sky)); box-shadow: 0 8px 20px rgba(27, 156, 216, .34); }
.ico-orange { background: linear-gradient(135deg, var(--amber), var(--orange)); box-shadow: 0 8px 20px rgba(245, 130, 31, .34); }
.ico-red    { background: linear-gradient(135deg, #e8556a, var(--crimson)); box-shadow: 0 8px 20px rgba(214, 58, 74, .32); }
.strength h3 { font-size: 20px; margin-bottom: 12px; }
.strength p { font-size: 15.5px; color: var(--d-text-mute); line-height: 1.72; }

/* ── Curriculum ────────────────────────────────────────────────────────── */
.stage { margin-top: 72px; }
.stage-head { display: flex; align-items: baseline; flex-wrap: wrap; gap: 8px 18px; padding-bottom: 18px; border-bottom: 1px solid var(--border); }
.stage-no {
  font-size: 12.5px; font-weight: 800; letter-spacing: .14em; text-transform: uppercase;
  color: #fff; padding: 5px 13px; border-radius: 999px;
}
/* 흰 글자를 얹는 면이라 밝은 브랜드색 그대로는 대비가 2.6~3.1에 그친다.
   같은 계열에서 명도만 낮춰 4.6~7.2로 올렸다. */
.stage-sky    .stage-no { background: linear-gradient(135deg, #127da8, #0f6690); }
.stage-orange .stage-no { background: linear-gradient(135deg, #c2410c, #a8480a); }
.stage-red    .stage-no { background: linear-gradient(135deg, #a81e3c, #8f1834); }
.stage-name { font-size: clamp(21px, 2.6vw, 27px); font-weight: 800; }
.stage-name em {
  font-style: normal; font-size: .62em; font-weight: 600; letter-spacing: .04em;
  color: var(--text-faint); margin-left: 8px;
}

/* 2단 고정 — 과정 수가 2·4·4라 어느 스테이지에도 고아 행이 생기지 않는다.
   폭이 넓어진 만큼 카드는 번호(좌) + 본문(우) 가로 배치로 짠다. */
.cards { margin-top: 26px; display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.card {
  position: relative; overflow: hidden;
  display: flex; align-items: flex-start; gap: 20px;
  padding: 28px 30px;
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: transform .3s var(--ease), box-shadow .3s var(--ease), border-color .3s var(--ease);
}
.card::before {
  content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 3px;
  transform: scaleY(0); transform-origin: top; transition: transform .34s var(--ease);
}
.stage-sky    .card::before { background: linear-gradient(180deg, #3fb6ea, var(--sky)); }
.stage-orange .card::before { background: linear-gradient(180deg, var(--amber), var(--orange)); }
.stage-red    .card::before { background: linear-gradient(180deg, #e8556a, var(--crimson)); }
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); border-color: transparent; }
.card:hover::before { transform: scaleY(1); }
.card-no {
  flex: none; width: 46px; height: 46px; border-radius: 13px;
  display: grid; place-items: center;
  font-size: 15px; font-weight: 800; letter-spacing: .02em;
  transition: background .3s var(--ease), color .3s var(--ease);
}
.stage-sky    .card-no { background: rgba(27, 156, 216, .10); color: #0d6f9e; }
.stage-orange .card-no { background: rgba(245, 130, 31, .11); color: #a8480a; }
.stage-red    .card-no { background: rgba(214, 58, 74, .10); color: #b02434; }
.card:hover .card-no { color: #fff; }
.stage-sky    .card:hover .card-no { background: linear-gradient(135deg, #3fb6ea, var(--sky)); }
.stage-orange .card:hover .card-no { background: linear-gradient(135deg, var(--amber), var(--orange)); }
.stage-red    .card:hover .card-no { background: linear-gradient(135deg, #e8556a, var(--crimson)); }
.card-body { min-width: 0; }
.card h4 { font-size: 19px; margin-bottom: 8px; }
.card p { font-size: 15.5px; color: var(--text-mute); line-height: 1.7; }

/* 교육 형태 */
.modes {
  margin-top: 80px; padding: 34px 8px;
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px;
  border-top: 1px solid var(--border); border-bottom: 1px solid var(--border);
}
.mode { padding: 6px 20px; border-left: 1px solid var(--border); }
.mode:first-child { border-left: 0; }
.mode-h { font-size: 16.5px; font-weight: 700; color: var(--navy); margin-bottom: 4px; }
.mode-d { font-size: 14.5px; color: var(--text-mute); line-height: 1.6; }

/* ── Online courses (인프런) ───────────────────────────────────────────── */
.courses { margin-top: 58px; display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.course {
  display: flex; flex-direction: column; overflow: hidden;
  background: #fff; border: 1px solid var(--border); border-radius: 20px;
  box-shadow: var(--shadow);
  transition: transform .3s var(--ease), box-shadow .3s var(--ease);
}
.course:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }

/* 썸네일 비율은 원본 셋이 모두 ~1.54라 하나로 묶어도 잘리는 데가 거의 없다. */
.course-thumb {
  display: block; position: relative; overflow: hidden;
  aspect-ratio: 1040 / 676; background: var(--bg-soft);
}
/* <picture> 는 기본이 inline 이라 높이가 잡히지 않는다. img 의 height:100% 가
   기댈 블록이 되도록 명시한다. */
.course-thumb picture { display: block; width: 100%; height: 100%; }
.course-thumb img {
  width: 100%; height: 100%; object-fit: cover;
  transition: transform .45s var(--ease);
}
.course:hover .course-thumb img { transform: scale(1.045); }

.course-body { display: flex; flex-direction: column; flex: 1; padding: 24px 24px 22px; }
.course-plat {
  align-self: flex-start; margin-bottom: 12px;
  font-size: 12px; font-weight: 700; letter-spacing: .04em;
  color: #0a7a53; background: rgba(10, 122, 83, .09);
  padding: 4px 11px; border-radius: 999px;
}
.course-title { font-size: 18.5px; font-weight: 700; line-height: 1.4; letter-spacing: -.03em; margin-bottom: 9px; }
.course-desc { font-size: 15px; color: var(--text-mute); line-height: 1.68; }
.course-go {
  margin-top: auto; padding-top: 20px;
  display: inline-flex; align-items: center; gap: 7px;
  font-size: 14.5px; font-weight: 700; color: var(--navy);
}
.course-go svg { width: 16px; height: 16px; transition: transform .28s var(--ease); }
.course:hover .course-go { color: var(--orange-ink); }
.course:hover .course-go svg { transform: translateX(5px); }

/* ── Platform ──────────────────────────────────────────────────────────── */
.platforms { margin-top: 58px; display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.platform {
  position: relative; overflow: hidden;
  display: flex; flex-direction: column;
  padding: 38px 36px 34px;
  background: #fff; border: 1px solid var(--border); border-radius: 22px;
  box-shadow: var(--shadow);
  transition: transform .3s var(--ease), box-shadow .3s var(--ease);
}
.platform::after {
  content: ""; position: absolute; inset: 0 0 auto 0; height: 4px;
  transform: scaleX(0); transform-origin: left; transition: transform .4s var(--ease);
}
.pf-classpia::after { background: linear-gradient(90deg, var(--amber), var(--orange), #1c6fb0); }
.pf-moaitso::after  { background: linear-gradient(90deg, #1f6fff, #10b3a3, #2b3a52); }
.platform:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.platform:hover::after { transform: scaleX(1); }

.pf-top { display: flex; align-items: center; gap: 18px; margin-bottom: 22px; }
.pf-logo { width: 58px; height: 58px; object-fit: contain; }
.platform h3 { font-size: 24px; font-weight: 800; }
.pf-url { font-size: 14px; font-weight: 600; color: var(--text-faint); letter-spacing: .01em; }
.pf-desc { font-size: 16px; color: var(--text-mute); line-height: 1.75; }
.pf-desc strong { color: var(--navy); font-weight: 700; }
.pf-tags { margin-top: 20px; display: flex; flex-wrap: wrap; gap: 7px; }
.pf-tags li {
  font-size: 13px; font-weight: 600; color: var(--text-mute);
  padding: 5px 12px; border-radius: 8px; background: var(--bg-soft);
}
.pf-go {
  margin-top: 26px; padding-top: 20px; border-top: 1px solid var(--border);
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 15px; font-weight: 700; color: var(--navy);
}
.pf-go svg { width: 17px; height: 17px; transition: transform .28s var(--ease); }
.platform:hover .pf-go svg { transform: translateX(5px); }
.pf-classpia:hover .pf-go { color: var(--orange-ink); }
.pf-moaitso:hover .pf-go  { color: #1a5fe0; }

/* ── Resources : 출간 도서 + 자료 공유 폴더 ────────────────────────────── */
.res-grid { margin-top: 58px; display: grid; grid-template-columns: 1.32fr 1fr; gap: 24px; align-items: stretch; }
.books { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }

.book {
  padding: 30px 26px 28px;
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  box-shadow: var(--shadow); text-align: center;
  transition: transform .3s var(--ease), box-shadow .3s var(--ease);
}
.book:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.book-cover {
  width: 168px; margin: 0 auto 20px; border-radius: 4px;
  filter: drop-shadow(0 14px 26px rgba(16, 33, 51, .18));
  transition: transform .35s var(--ease);
}
.book:hover .book-cover { transform: translateY(-3px) scale(1.03); }
.book-badge {
  display: inline-block; margin-bottom: 10px;
  font-size: 12px; font-weight: 700; letter-spacing: .06em; color: #fff;
  padding: 3px 11px; border-radius: 999px;
}
.badge-dev { background: #d9333f; }
.badge-ops { background: #9c1f6b; }
.book h3 { font-size: 18px; margin-bottom: 6px; }
.book-sub { font-size: 14.5px; color: var(--text-mute); line-height: 1.6; }
.book-by { margin-top: 10px; font-size: 13.5px; color: var(--text-faint); }

.drive {
  position: relative; overflow: hidden;
  display: flex; flex-direction: column;
  padding: 36px 34px 32px; border-radius: 22px; color: #fff;
  background:
    radial-gradient(70% 80% at 92% 4%, rgba(27, 156, 216, .34), transparent 62%),
    radial-gradient(60% 70% at 0% 100%, rgba(245, 130, 31, .28), transparent 64%),
    linear-gradient(160deg, var(--navy) 0%, var(--navy-deep) 100%);
  box-shadow: 0 18px 44px rgba(12, 39, 64, .28);
  transition: transform .3s var(--ease), box-shadow .3s var(--ease);
}
.drive:hover { transform: translateY(-6px); box-shadow: 0 26px 60px rgba(12, 39, 64, .36); }
.drive-ico {
  width: 52px; height: 52px; border-radius: 15px; margin-bottom: 22px;
  display: grid; place-items: center; color: #fff;
  background: linear-gradient(135deg, var(--amber), var(--orange));
  box-shadow: 0 10px 24px rgba(245, 130, 31, .38);
}
.drive-ico svg { width: 26px; height: 26px; }
.drive-eyebrow {
  font-size: 12.5px; font-weight: 700; letter-spacing: .16em; text-transform: uppercase;
  color: var(--amber); margin-bottom: 8px;
}
.drive h3 { font-size: 23px; font-weight: 800; margin-bottom: 12px; }
.drive-desc { font-size: 15.5px; color: var(--d-text-mute); line-height: 1.72; }
.drive-go {
  margin-top: auto; padding-top: 26px;
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 15.5px; font-weight: 700; color: #fff;
}
.drive-go svg { width: 17px; height: 17px; transition: transform .28s var(--ease); }
.drive:hover .drive-go svg { transform: translateX(5px); }

/* ── Journey timeline ──────────────────────────────────────────────────── */
.timeline {
  margin-top: 66px; display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px;
  position: relative;
}
.timeline::before {
  content: ""; position: absolute; left: 0; right: 0; top: 7px; height: 2px;
  background: linear-gradient(90deg, rgba(255,255,255,.10), rgba(255,255,255,.28), rgba(255,255,255,.10));
}
.tl-item { position: relative; padding-top: 34px; padding-right: 14px; }
.tl-dot {
  position: absolute; top: 0; left: 0; width: 16px; height: 16px; border-radius: 50%;
  box-shadow: 0 0 0 5px rgba(255, 255, 255, .10);
}
.tl-navy   { background: linear-gradient(135deg, #8fb6d6, #4d7ea6); }
.tl-sky    { background: linear-gradient(135deg, #6fd0f5, var(--sky)); }
.tl-orange { background: linear-gradient(135deg, var(--amber), var(--orange)); }
.tl-red    { background: linear-gradient(135deg, #e8556a, var(--crimson)); }
.tl-tag {
  font-size: 12.5px; font-weight: 700; letter-spacing: .1em; text-transform: uppercase;
  color: var(--d-text-mute); margin-bottom: 8px;
}
.tl-item h3 { font-size: 20px; margin-bottom: 10px; }
.tl-desc { font-size: 15px; color: var(--d-text-mute); line-height: 1.7; }

/* ── footer ────────────────────────────────────────────────────────────── */
.site-footer { background: var(--navy-ink); color: #fff; padding: 72px 0 30px; }
.footer-inner { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 44px; }
.foot-logo { display: flex; align-items: center; gap: 13px; margin-bottom: 18px; }
.foot-logo .brand-mark { height: 48px; width: 48px; }
.foot-logo .brand-name { font-size: 26px; }
.foot-tag { font-size: 14.5px; color: var(--d-text-mute); letter-spacing: .01em; }
.foot-ceo { margin-top: 6px; font-size: 14.5px; color: rgba(169, 189, 210, .7); }
.foot-nav { display: flex; gap: 72px; }
.foot-col { display: flex; flex-direction: column; }
.foot-h { font-size: 13px; font-weight: 700; letter-spacing: .12em; text-transform: uppercase; color: var(--orange); margin-bottom: 3px; }
/* gap 대신 padding 으로 띄운다 — 눈에 보이는 간격은 같지만 손가락이 닿는 면이 44px 이 된다. */
.foot-col a {
  font-size: 15px; color: var(--d-text-mute);
  padding: 9px 0; transition: color .2s var(--ease);
}
.foot-col a:hover { color: #fff; }
.foot-bottom {
  margin-top: 56px; padding-top: 24px; border-top: 1px solid rgba(255, 255, 255, .1);
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: 10px;
  font-size: 14px; color: rgba(169, 189, 210, .72);
}
.foot-domain { font-weight: 600; letter-spacing: .02em; }

/* ── scroll reveal ─────────────────────────────────────────────────────── */
.reveal { opacity: 0; transform: translateY(22px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
.reveal.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; }

/* ── responsive ────────────────────────────────────────────────────────── */
@media (max-width: 1024px) {
  /* 강점은 3개뿐이라 2단으로 내리면 2+1 고아 행이 된다. 3단을 유지하다 한 번에 1단으로. */
  .strengths { gap: 16px; }
  .timeline { grid-template-columns: repeat(2, 1fr); row-gap: 40px; }
  .timeline::before { display: none; }
  .tl-item { padding-left: 0; }
  .modes { grid-template-columns: repeat(2, 1fr); row-gap: 24px; }
  .mode:nth-child(3) { border-left: 0; }
}

@media (max-width: 860px) {
  body { font-size: 16px; }
  .section { padding: 84px 0; }
  .hero { padding: 76px 0 96px; min-height: auto; }
  .hero-mark { right: -140px; width: 460px; opacity: .07; }
  .scroll-hint { display: none; }

  .nav-toggle { display: flex; }
  .nav {
    position: fixed; left: 0; right: 0; top: var(--header-h);
    flex-direction: column; align-items: stretch; gap: 0;
    padding: 10px 24px 26px;
    background: rgba(255, 255, 255, .97);
    backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--border);
    box-shadow: 0 18px 40px rgba(16, 33, 51, .12);
    transform: translateY(-12px); opacity: 0; visibility: hidden; pointer-events: none;
    transition: opacity .24s var(--ease), transform .24s var(--ease), visibility .24s;
  }
  .nav.open { transform: none; opacity: 1; visibility: visible; pointer-events: auto; }
  .nav > a:not(.btn) { padding: 15px 2px; font-size: 17px; color: var(--navy); border-bottom: 1px solid var(--border); }
  .nav > a:not(.btn)::after { display: none; }
  .nav-cta { margin: 20px 0 0; align-self: flex-start; }

  .platforms { grid-template-columns: 1fr; }
  .platform { padding: 32px 26px 28px; }
  /* 강의는 3개뿐이라 2단으로 내리면 2+1 고아 행이 된다 — 3단에서 바로 1단으로. */
  .cards, .strengths, .courses { grid-template-columns: 1fr; }
  /* 1단에서 카드가 본문 폭을 다 먹으면 썸네일이 원본보다 크게 늘어나 흐려진다.
     ms_sql.png(454px)이 가장 작아서, 그 폭에 맞춰 카드 폭을 묶는다. */
  .courses { max-width: 520px; margin-left: auto; margin-right: auto; }
  .res-grid { grid-template-columns: 1fr; }
  .drive { padding: 32px 26px 28px; }
  .drive-go { margin-top: 26px; padding-top: 0; }
  .brand-mark { height: 38px; width: 38px; }
  .brand-name { font-size: 21px; }
}

@media (max-width: 600px) {
  .wrap { padding: 0 20px; }
  .strengths, .timeline { grid-template-columns: 1fr; }
  .modes { grid-template-columns: 1fr; padding: 26px 0; }
  .mode { border-left: 0; padding: 6px 4px; }
  .br-pc { display: none; }
  .hero-actions .btn { flex: 1 1 100%; }
  .strength { padding: 28px 24px; }
  .books { gap: 12px; }
  .book { padding: 22px 14px 20px; }   /* 좁은 폭에서 표지가 눌리지 않게 여백을 줄인다 */
  .foot-nav { gap: 44px; }
  .footer-inner { flex-direction: column; gap: 36px; }
}

/* ── 접근성: 모션 최소화 ───────────────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important; animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
  .reveal { opacity: 1; transform: none; }
}

/* ── 인쇄 ──────────────────────────────────────────────────────────────── */
@media print {
  .site-header, .scroll-hint, .hero-glow, .hero-mark { display: none; }
  .band-dark, .site-footer { background: #fff !important; color: #000 !important; }
  .reveal { opacity: 1 !important; transform: none !important; }
}