:root{
  /* ---- Theme (Dark / Clean) ---- */
  --bg0:#05070c;
  --bg1:#070b12;
  --bg2:#0b1220;
  --card:#0c1626;
  --card2:#0a1424;
  --line:rgba(255,255,255,.08);

  /* ✅ 가독성 강화 */
  --text:rgba(255,255,255,.96);
  --muted:rgba(255,255,255,.72);
  --muted2:rgba(255,255,255,.62);

  --shadow: 0 18px 50px rgba(0,0,0,.55);
  --shadow2: 0 10px 26px rgba(0,0,0,.45);

  --radius: 18px;
  --radius2: 14px;

  --focus: rgba(120,180,255,.22);
  --focusLine: rgba(120,180,255,.35);
}

*{ box-sizing:border-box; }
html,body{ height:100%; }
body{
  margin:0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, "Noto Sans KR", "Hiragino Sans", "Yu Gothic", Arial, sans-serif;
  color: var(--text);

  /* ✅ 유튜브 배경이 보이도록 body는 투명(배경은 video-overlay가 담당) */
  background: transparent;

  overflow-x:hidden;

  /* ✅ 배경 영상 대비 글자 보호 */
  text-shadow: 0 2px 10px rgba(0,0,0,.55);
}

a{ color:inherit; text-decoration:none; }
button{ font:inherit; color:inherit; }

.wrap{
  min-height:100%;
  display:flex;
  flex-direction:column;
}

/* ---- Top Bar ---- */
.topbar{
  position:sticky;
  top:0;
  z-index:50;
  backdrop-filter: blur(12px);
  background: linear-gradient(180deg, rgba(8,12,18,.92), rgba(8,12,18,.55));
  border-bottom:1px solid var(--line);
}
.topbar-inner{
  max-width: 1100px;
  margin: 0 auto;
  padding: 14px 18px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:14px;
}
.brand{
  display:flex;
  align-items:center;
  gap:12px;
  min-width: 220px;
}
.logo{
  width:70px; height:70px;
  border-radius: 999px;
  background:
    radial-gradient(circle at 30% 30%, rgba(255,255,255,.18), transparent 40%),
    linear-gradient(135deg, rgba(90,160,255,.85), rgba(90,255,200,.65));
  box-shadow: 0 10px 22px rgba(0,0,0,.45);
  border:1px solid rgba(255,255,255,.18);
  display:grid;
  place-items:center;
  font-weight:800;
  letter-spacing:.5px;
  font-size: 14px;
}
.brand-text{
  display:flex;
  flex-direction:column;
  line-height:1.1;
}
.brand-text .name{
  font-weight: 800;
  letter-spacing:.2px;
  font-size: 15px;
}
.brand-text .tag{
  font-size: 12px;
  color: var(--muted);
  margin-top:4px;
  text-shadow: 0 1px 10px rgba(0,0,0,.55);
}

.center-title{
  text-align:center;
  font-size: 22px;
  font-weight: 850;
  letter-spacing:.2px;
  flex:1;
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
  text-shadow: 0 2px 14px rgba(0,0,0,.70);
}

.actions{
  display:flex;
  align-items:center;
  gap:10px;
  justify-content:flex-end;
  min-width: 220px;
}

/* ---- Language ---- */
.lang{
  display:flex;
  align-items:center;
  gap:6px;
  padding: 8px 10px;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: rgba(255,255,255,.03);
  box-shadow: 0 10px 26px rgba(0,0,0,.25);
}
.lang label{
  font-size: 12px;
  color: var(--muted);
  margin-right: 6px;
}
.lang select{
  appearance:none;
  background: transparent;
  border:none;
  outline:none;
  color: var(--text);
  font-weight: 700;
  padding-right: 18px;
  cursor:pointer;
}
.lang .chev{
  width: 0; height: 0;
  border-left: 6px solid transparent;
  border-right: 6px solid transparent;
  border-top: 7px solid rgba(255,255,255,.62);
  margin-left: -10px;
  pointer-events:none;
}

/* ---- Menu Button ---- */
.menu-btn{
  width: 42px;
  height: 42px;
  border-radius: 14px;
  border: 1px solid var(--line);
  background: rgba(255,255,255,.03);
  box-shadow: 0 10px 26px rgba(0,0,0,.25);
  cursor:pointer;
  display:grid;
  place-items:center;
  transition: transform .12s ease, border-color .12s ease, background .12s ease;
}
.menu-btn:active{ transform: scale(.98); }
.menu-btn:hover{
  border-color: rgba(255,255,255,.16);
  background: rgba(255,255,255,.05);
}
.hamburger{
  width:18px;
  height:12px;
  position:relative;
}
.hamburger span{
  position:absolute;
  left:0; right:0;
  height:2px;
  background: rgba(255,255,255,.78);
  border-radius:999px;
}
.hamburger span:nth-child(1){ top:0; }
.hamburger span:nth-child(2){ top:5px; opacity:.9; }
.hamburger span:nth-child(3){ bottom:0; opacity:.85; }

/* ---- Layout ---- */
main{
  max-width: 1100px;
  margin: 0 auto;
  padding: 26px 18px 60px;
  width:100%;
}

.hero{
  margin-top: 8px;
  padding: 20px;
  border-radius: var(--radius);
  background:
    radial-gradient(1000px 500px at 10% 0%, rgba(80,160,255,.10), transparent 55%),
    radial-gradient(800px 500px at 90% 0%, rgba(90,255,200,.08), transparent 55%),
    /* ✅ 히어로는 더 불투명하게 */
    linear-gradient(180deg, rgba(0,0,0,.38), rgba(0,0,0,.22));
  border: 1px solid rgba(255,255,255,.12);
  box-shadow: var(--shadow2);
  display:flex;
  align-items:flex-start;
  justify-content:space-between;
  gap:18px;
  overflow:hidden;
  position:relative;
}
.hero::after{
  content:"";
  position:absolute;
  inset:-2px;
  border-radius: var(--radius);
  pointer-events:none;
  box-shadow: 0 0 0 0 rgba(0,0,0,0);
}

.hero .hgroup{
  max-width: 720px;
}
.hero .eyebrow{
  font-size: 12px;
  color: var(--muted);
  letter-spacing:.18em;
  text-transform: uppercase;
  text-shadow: 0 1px 10px rgba(0,0,0,.55);
}
.hero h1{
  margin: 10px 0 10px;
  font-size: 30px;
  line-height:1.15;
  letter-spacing:-.2px;
  text-shadow: 0 2px 14px rgba(0,0,0,.70);
}
.hero p{
  margin:0;
  color: var(--muted);
  font-size: 14px;
  line-height:1.6;
  text-shadow: 0 1px 10px rgba(0,0,0,.55);
}
.hero .cta{
  display:flex;
  align-items:center;
  gap:10px;
  margin-top: 14px;
  flex-wrap:wrap;
}
.pill{
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding: 10px 12px;
  border-radius: 999px;
  border: 1px solid rgba(255,255,255,.10);
  background: rgba(255,255,255,.04);
  color: rgba(255,255,255,.90);
  font-weight: 750;
  font-size: 13px;
  transition: transform .12s ease, background .12s ease, border-color .12s ease;
  cursor:pointer;
  user-select:none;
}
.pill:hover{
  border-color: rgba(255,255,255,.18);
  background: rgba(255,255,255,.06);
}
.pill:active{ transform: scale(.99); }
.pill .dot{
  width: 8px; height: 8px;
  border-radius: 999px;
  background: rgba(120,180,255,.9);
  box-shadow: 0 0 0 6px rgba(120,180,255,.12);
}
.pill.books .dot{ background: rgba(255,180,120,.95); box-shadow: 0 0 0 6px rgba(255,180,120,.12); }
.pill.courses .dot{ background: rgba(120,255,190,.92); box-shadow: 0 0 0 6px rgba(120,255,190,.10); }

/* ---- Cards (Main menu-like) ---- */
.section-title{
  margin: 26px 0 14px;
  font-size: 14px;
  color: rgba(255,255,255,.90);
  font-weight: 800;
  letter-spacing:.2px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  text-shadow: 0 2px 12px rgba(0,0,0,.65);
}
.section-title small{
  font-weight:650;
  color: var(--muted);
  text-shadow: 0 1px 10px rgba(0,0,0,.55);
}

.cardlist{
  display:flex;
  flex-direction:column;
  gap:14px;
  margin-top: 12px;
}

.card{
  display:flex;
  align-items:center;
  gap:16px;
  padding: 18px 18px;
  border-radius: var(--radius);
  background:
    radial-gradient(900px 420px at 10% 0%, rgba(255,255,255,.05), transparent 55%),
    /* ✅ 카드도 더 불투명하게 */
    linear-gradient(180deg, rgba(0,0,0,.42), rgba(0,0,0,.24));
  border: 1px solid rgba(255,255,255,.12);
  box-shadow: var(--shadow2);
  position:relative;
  transition: transform .12s ease, border-color .12s ease, background .12s ease;
}
.card:hover{
  transform: translateY(-1px);
  border-color: rgba(255,255,255,.16);
  background:
    radial-gradient(900px 420px at 10% 0%, rgba(255,255,255,.06), transparent 55%),
    linear-gradient(180deg, rgba(0,0,0,.46), rgba(0,0,0,.26));
}
.card:focus-within{
  box-shadow: var(--shadow2), 0 0 0 4px var(--focus);
  border-color: var(--focusLine);
}

.icon{
  width: 44px; height: 44px;
  border-radius: 14px;
  border: 1px solid rgba(255,255,255,.12);
  background: rgba(255,255,255,.03);
  display:grid;
  place-items:center;
  flex: 0 0 auto;
  box-shadow: 0 10px 26px rgba(0,0,0,.25);
}
.card .meta{
  display:flex;
  flex-direction:column;
  gap:6px;
  min-width: 0;
  flex:1;
}
.kicker{
  font-size: 12px;
  color: var(--muted);
  font-weight: 800;
  letter-spacing:.2px;
  text-shadow: 0 1px 10px rgba(0,0,0,.55);
}
.title{
  font-size: 15px;
  font-weight: 850;
  letter-spacing:.1px;
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
  text-shadow: 0 2px 14px rgba(0,0,0,.70);
}
.desc{
  font-size: 13px;
  color: var(--muted2);
  line-height:1.45;
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
  text-shadow: 0 1px 10px rgba(0,0,0,.55);
}

/* 카드 오른쪽 '보기 →' 버튼 숨김 */
.go{
  display:none !important;
}
.card:hover .go{
  background: rgba(255,255,255,.05);
  border-color: rgba(255,255,255,.16);
}

/* ---- Drawer ---- */
.backdrop{
  position:fixed;
  inset:0;
  background: rgba(0,0,0,.55);
  opacity:0;
  pointer-events:none;
  transition: opacity .18s ease;
  z-index:90;
}
.backdrop.open{
  opacity:1;
  pointer-events:auto;
}
.drawer{
  position:fixed;
  top:0; right:0;
  height:100%;
  width: min(360px, 92vw);
  background:
    radial-gradient(800px 500px at 50% 0%, rgba(120,180,255,.10), transparent 60%),
    linear-gradient(180deg, rgba(10,14,20,.98), rgba(10,14,20,.92));
  border-left: 1px solid rgba(255,255,255,.10);
  box-shadow: -20px 0 60px rgba(0,0,0,.55);
  transform: translateX(110%);
  transition: transform .18s ease;
  z-index:100;
  display:flex;
  flex-direction:column;
}
.drawer.open{ transform: translateX(0); }
.drawer-head{
  padding: 18px 18px 12px;
  border-bottom:1px solid rgba(255,255,255,.08);
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:10px;
}
.drawer-head .dt{
  font-weight: 900;
  letter-spacing:.2px;
  text-shadow: 0 2px 12px rgba(0,0,0,.65);
}
.close-btn{
  width: 40px; height: 40px;
  border-radius: 14px;
  border:1px solid rgba(255,255,255,.10);
  background: rgba(255,255,255,.03);
  cursor:pointer;
}
.drawer-body{
  padding: 10px 12px 18px;
  overflow:auto;
}
.navgrp{
  margin: 12px 0;
  border:1px solid rgba(255,255,255,.08);
  background: rgba(255,255,255,.02);
  border-radius: 16px;
  overflow:hidden;
}
.navgrp .gh{
  padding: 12px 14px;
  font-size: 12px;
  color: var(--muted);
  font-weight: 900;
  letter-spacing:.12em;
  text-transform: uppercase;
  border-bottom:1px solid rgba(255,255,255,.07);
  text-shadow: 0 1px 10px rgba(0,0,0,.55);
}
.navgrp a{
  display:flex;
  align-items:center;
  justify-content:space-between;
  padding: 12px 14px;
  border-bottom:1px solid rgba(255,255,255,.06);
  font-weight: 750;
  color: rgba(255,255,255,.90);
  text-shadow: 0 1px 10px rgba(0,0,0,.55);
}
.navgrp a:last-child{ border-bottom:none; }
.navgrp a:hover{
  background: rgba(255,255,255,.04);
}
.navgrp a span{
  color: rgba(255,255,255,.60);
  font-weight: 900;
}

/* ---- Footer ---- */
footer{
  margin-top:auto;
  border-top:1px solid rgba(255,255,255,.08);
  background: rgba(0,0,0,.22);
}
.footer-inner{
  max-width:1100px;
  margin:0 auto;
  padding: 18px 18px;
  display:flex;
  flex-wrap:wrap;
  gap:10px 16px;
  align-items:center;
  justify-content:space-between;
  color: var(--muted);
  font-size: 12px;
  text-shadow: 0 1px 10px rgba(0,0,0,.55);
}

/* ✅ Header logo image (과대 표시 방지 잠금) */
.logo-img{
  width: 70px !important;
  height: 70px !important;
  max-width: 70px !important;
  max-height: 70px !important;
  object-fit: contain;
  border-radius: 50%;
  box-shadow: 0 8px 20px rgba(0,0,0,.45);
  background: transparent;
}

/* ---- Responsive ---- */
@media (max-width: 720px){
  .brand{ min-width: auto; }
  .actions{ min-width: auto; }
  .center-title{ font-size: 18px; }
  .hero h1{ font-size: 24px; }
  .desc{ display:none; }
  .go{ padding: 9px 10px; }
}

/* ---- Simple SVG icon styling ---- */
svg{ display:block; }
.stroke{ stroke: rgba(255,255,255,.78); }
.stroke2{ stroke: rgba(255,255,255,.62); }


/* =========================================================
   ✅ YouTube Background Video + Overlay (가독성 최적화)
   ========================================================= */
#video-background{
  position: fixed;
  inset: 0;
  width: 100vw;
  height: 100vh;
  z-index: -2;          /* 콘텐츠 뒤 */
  overflow: hidden;
  background: #000;
}

/* ✅ 오버레이를 더 어둡게 + 검은 막 추가 */
.video-overlay{
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;

  background:
    radial-gradient(1200px 700px at 20% 0%, rgba(50,110,255,.10), transparent 60%),
    radial-gradient(900px 600px at 80% 10%, rgba(120,220,255,.08), transparent 60%),
    radial-gradient(900px 600px at 50% 100%, rgba(120,255,190,.05), transparent 55%),
    linear-gradient(180deg, rgba(5,7,12,.72), rgba(7,11,18,.68) 40%, rgba(5,7,12,.78)),
    rgba(0,0,0,.35);
}

/* iframe은 JS에서 크기조정하지만, 위치/클릭방지 기본값은 CSS에서 고정 */
#video-background iframe{
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  pointer-events: none;
}