/* ============================================================
   AI Academy LMS — 공유 엔진 스타일
   테마: [data-theme="city"](라이트·경쾌) / [data-theme="starcraft"](다크·시네마틱)
   ============================================================ */

/* ---------- 테마 토큰 ---------- */
:root {
  --font: "Pretendard", "Noto Sans KR", system-ui, -apple-system, sans-serif;
  --radius: 14px;
  --radius-sm: 9px;
  --sidebar-w: 320px;
  --topbar-h: 60px;
  --maxw: 1240px;
}

/* City — 밝고 경쾌하되 성숙 */
:root[data-theme="city"] {
  --bg: #eef1f7;
  --surface: #ffffff;
  --surface-2: #f4f7fc;
  --ink: #1c2233;
  --sub: #5b657c;
  --faint: #8b95a9;
  --line: #e3e8f1;
  --line-2: #d3dae7;
  --accent: #3457d5;
  --accent-ink: #ffffff;
  --accent-soft: #eaf0ff;
  --accent-2: #12b886;
  --good: #12b886;
  --good-soft: #e2f7ef;
  --bad: #e5484d;
  --bad-soft: #fdecec;
  --warn: #f08c00;
  --shadow: 0 6px 22px rgba(28, 40, 80, .09);
  --shadow-lg: 0 18px 50px rgba(28, 40, 80, .16);
  --brand-grad: linear-gradient(135deg, #3457d5, #12b886);
  --hero-ink: #ffffff;
}

/* Starcraft — 진중·시네마틱·차분(성인) */
:root[data-theme="starcraft"] {
  --bg: #0a0d13;
  --surface: #12171f;
  --surface-2: #171d27;
  --ink: #e7ecf4;
  --sub: #9aa6b8;
  --faint: #66718a;
  --line: #232b38;
  --line-2: #2e394a;
  --accent: #4a9eff;
  --accent-ink: #05080d;
  --accent-soft: #14243a;
  --accent-2: #c8a24a;
  --good: #35c08a;
  --good-soft: #0f2a20;
  --bad: #ef5f6b;
  --bad-soft: #2a1418;
  --warn: #d9a441;
  --shadow: 0 8px 28px rgba(0, 0, 0, .45);
  --shadow-lg: 0 24px 60px rgba(0, 0, 0, .6);
  --brand-grad: linear-gradient(135deg, #1b2a44, #0a0d13 70%);
  --hero-ink: #eaf1fb;
}

/* ---------- 베이스 ---------- */
* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--ink);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-decoration: none; }
button { font-family: inherit; cursor: pointer; }
::selection { background: color-mix(in srgb, var(--accent) 30%, transparent); }

/* 스크롤바 */
*::-webkit-scrollbar { width: 10px; height: 10px; }
*::-webkit-scrollbar-thumb { background: var(--line-2); border-radius: 20px; }
*::-webkit-scrollbar-track { background: transparent; }

/* ---------- 앱 셸 ---------- */
.app { display: grid; grid-template-columns: var(--sidebar-w) 1fr; height: 100vh; }

/* ---------- 사이드바 ---------- */
.side {
  background: var(--surface);
  border-right: 1px solid var(--line);
  display: flex; flex-direction: column;
  min-height: 0;
}
.brand {
  padding: 18px 20px; border-bottom: 1px solid var(--line);
  display: flex; align-items: center; gap: 12px;
}
.brand-badge {
  width: 40px; height: 40px; border-radius: 11px; flex: none;
  background: var(--brand-grad); color: var(--hero-ink);
  display: grid; place-items: center; font-weight: 900; font-size: 19px;
  box-shadow: var(--shadow);
}
.brand-txt { min-width: 0; }
.brand-txt .kicker { font-size: 11px; letter-spacing: .18em; color: var(--faint); font-weight: 800; text-transform: uppercase; }
.brand-txt .name { font-size: 15px; font-weight: 800; color: var(--ink); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

.progress-wrap { padding: 14px 20px; border-bottom: 1px solid var(--line); }
.progress-line { display: flex; justify-content: space-between; font-size: 12px; color: var(--sub); margin-bottom: 7px; font-weight: 700; }
.progress-bar { height: 7px; background: var(--surface-2); border-radius: 20px; overflow: hidden; border: 1px solid var(--line); }
.progress-fill { height: 100%; background: var(--brand-grad); border-radius: 20px; transition: width .4s ease; }

.outline { flex: 1; overflow-y: auto; padding: 8px 12px 40px; }

.sess { margin-bottom: 4px; }
.sess-head {
  display: flex; align-items: center; gap: 9px; width: 100%;
  padding: 11px 10px; border: none; background: transparent; color: var(--ink);
  text-align: left; border-radius: var(--radius-sm); font-size: 13.5px;
}
.sess-head:hover { background: var(--surface-2); }
.sess-num {
  width: 26px; height: 26px; border-radius: 8px; flex: none;
  background: var(--surface-2); border: 1px solid var(--line-2);
  display: grid; place-items: center; font-weight: 800; font-size: 12.5px; color: var(--sub);
}
.sess.done .sess-num { background: var(--good-soft); border-color: transparent; color: var(--good); }
.sess-title { flex: 1; font-weight: 700; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.sess-chev { color: var(--faint); font-size: 11px; transition: transform .2s; }
.sess.open .sess-chev { transform: rotate(90deg); }

.steps { display: none; padding: 2px 0 8px 6px; margin-left: 18px; border-left: 1.5px solid var(--line); }
.sess.open .steps { display: block; }
.step {
  display: flex; align-items: center; gap: 9px; width: 100%;
  padding: 7px 10px; border: none; background: transparent; color: var(--sub);
  text-align: left; border-radius: 8px; font-size: 12.5px; line-height: 1.35;
}
.step:hover { background: var(--surface-2); color: var(--ink); }
.step.active { background: var(--accent-soft); color: var(--accent); font-weight: 700; }
.step-ico {
  width: 20px; height: 20px; border-radius: 6px; flex: none; display: grid; place-items: center;
  font-size: 11px; background: var(--surface-2); border: 1px solid var(--line); color: var(--faint);
}
.step.active .step-ico { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.step.done .step-ico { background: var(--good); border-color: var(--good); color: #fff; }
.step-label { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.step-kind { font-size: 10px; color: var(--faint); font-weight: 700; }

/* ---------- 메인 ---------- */
.main { min-width: 0; display: flex; flex-direction: column; height: 100vh; }
.topbar {
  height: var(--topbar-h); flex: none; display: flex; align-items: center; gap: 14px;
  padding: 0 24px; border-bottom: 1px solid var(--line); background: color-mix(in srgb, var(--surface) 82%, transparent);
  backdrop-filter: blur(8px); position: sticky; top: 0; z-index: 5;
}
.topbar .crumb { font-size: 13px; color: var(--sub); font-weight: 600; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.topbar .crumb b { color: var(--ink); }
.topbar .spacer { flex: 1; }
.tb-btn {
  border: 1px solid var(--line-2); background: var(--surface); color: var(--sub);
  padding: 7px 13px; border-radius: 9px; font-size: 12.5px; font-weight: 700;
  display: inline-flex; align-items: center; gap: 6px;
}
.tb-btn:hover { border-color: var(--accent); color: var(--accent); }

.scroll { flex: 1; overflow-y: auto; }
.stage { max-width: var(--maxw); margin: 0 auto; padding: 34px 28px 90px; }

/* 스텝 헤더 */
.step-hd { margin-bottom: 20px; }
.step-hd .eyebrow { display: inline-flex; align-items: center; gap: 8px; font-size: 12px; font-weight: 800; letter-spacing: .04em; color: var(--accent); text-transform: uppercase; margin-bottom: 10px; }
.step-hd .eyebrow .dot { width: 6px; height: 6px; border-radius: 50%; background: var(--accent); }
.step-hd h1 { margin: 0; font-size: 27px; font-weight: 900; letter-spacing: -.02em; line-height: 1.25; }
.step-hd .sub { margin: 8px 0 0; color: var(--sub); font-size: 15px; }

/* 카드 공통 */
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); overflow: hidden; }

/* ---------- 영상 ---------- */
.video-card video { width: 100%; display: block; background: #000; aspect-ratio: 16/9; }
.video-meta { padding: 16px 20px; display: flex; align-items: center; gap: 14px; }
.video-meta .role-pill { font-size: 11.5px; font-weight: 800; padding: 5px 11px; border-radius: 20px; background: var(--accent-soft); color: var(--accent); }
.video-meta .vtitle { font-weight: 700; font-size: 15px; flex: 1; min-width: 0; }
.transcript { border-top: 1px solid var(--line); }
.transcript summary { padding: 13px 20px; font-weight: 700; font-size: 13.5px; color: var(--sub); cursor: pointer; list-style: none; display: flex; align-items: center; gap: 8px; }
.transcript summary::-webkit-details-marker { display: none; }
.transcript summary:hover { color: var(--ink); }
.transcript .tbody { padding: 4px 20px 20px; color: var(--sub); font-size: 14px; max-height: 320px; overflow-y: auto; white-space: pre-wrap; }

/* ---------- 세션 인트로 ---------- */
.intro-hero {
  border-radius: var(--radius); padding: 34px 34px; color: var(--hero-ink);
  background: var(--brand-grad); box-shadow: var(--shadow-lg); position: relative; overflow: hidden;
}
.intro-hero .badge { font-size: 12px; letter-spacing: .2em; font-weight: 800; opacity: .85; text-transform: uppercase; }
.intro-hero h1 { margin: 12px 0 0; font-size: 30px; font-weight: 900; letter-spacing: -.02em; }
.intro-stats { display: flex; gap: 10px; margin-top: 20px; flex-wrap: wrap; }
.intro-stat { background: rgba(255,255,255,.16); border: 1px solid rgba(255,255,255,.28); border-radius: 20px; padding: 6px 15px; font-weight: 800; font-size: 13px; }
.goals { margin-top: 18px; }
.goals h3 { font-size: 14px; font-weight: 800; color: var(--sub); margin: 0 0 12px; text-transform: uppercase; letter-spacing: .04em; }
.goals ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 10px; }
.goals li { display: flex; gap: 12px; padding: 14px 16px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-sm); font-size: 14.5px; }
.goals li .g-ic { color: var(--accent); font-weight: 900; flex: none; }

/* ---------- 퀴즈 ---------- */
.quiz-q { padding: 22px 24px; border-bottom: 1px solid var(--line); }
.quiz-q:last-child { border-bottom: none; }
.quiz-q .qn { font-size: 12px; font-weight: 800; color: var(--faint); letter-spacing: .04em; }
.quiz-q .qt { font-size: 16px; font-weight: 700; margin: 6px 0 16px; }
.choices { display: grid; gap: 9px; }
.choice {
  display: flex; align-items: center; gap: 12px; padding: 13px 15px;
  border: 1.5px solid var(--line-2); border-radius: var(--radius-sm); background: var(--surface);
  font-size: 14.5px; color: var(--ink); text-align: left; transition: border-color .15s, background .15s;
}
.choice:hover { border-color: var(--accent); }
.choice .mark { width: 22px; height: 22px; border-radius: 50%; border: 2px solid var(--line-2); flex: none; display: grid; place-items: center; font-size: 12px; font-weight: 800; color: transparent; }
.choice.sel { border-color: var(--accent); background: var(--accent-soft); }
.choice.sel .mark { border-color: var(--accent); background: var(--accent); color: var(--accent-ink); }
.quiz.graded .choice { cursor: default; pointer-events: none; }
.quiz.graded .choice.correct { border-color: var(--good); background: var(--good-soft); }
.quiz.graded .choice.correct .mark { border-color: var(--good); background: var(--good); color: #fff; }
.quiz.graded .choice.wrong { border-color: var(--bad); background: var(--bad-soft); }
.quiz.graded .choice.wrong .mark { border-color: var(--bad); background: var(--bad); color: #fff; }
.explain {
  display: none; margin-top: 14px; padding: 14px 16px; border-radius: var(--radius-sm);
  background: var(--surface-2); border: 1px solid var(--line); font-size: 14px; color: var(--sub);
}
.explain b { color: var(--ink); }
.quiz.graded .explain { display: block; }
.explain .verdict { font-weight: 800; margin-right: 6px; }
.explain .verdict.ok { color: var(--good); }
.explain .verdict.no { color: var(--bad); }

.quiz-foot { padding: 20px 24px; display: flex; align-items: center; gap: 14px; }
.quiz-score { font-weight: 800; font-size: 15px; display: none; }
.quiz.graded .quiz-score { display: block; }
.quiz-score .num { color: var(--accent); }

/* ---------- 워크북 활동 ---------- */
.activity { padding: 22px 24px; border-bottom: 1px solid var(--line); }
.activity:last-child { border-bottom: none; }
.activity .a-top { display: flex; align-items: center; gap: 10px; margin-bottom: 5px; }
.activity .a-phase { font-size: 10.5px; font-weight: 800; letter-spacing: .05em; text-transform: uppercase; padding: 3px 9px; border-radius: 6px; background: var(--accent-soft); color: var(--accent); }
.activity .a-title { font-weight: 800; font-size: 16px; }
.activity .a-prompt { color: var(--sub); font-size: 14.5px; margin: 4px 0 12px; }
.activity .a-hint { font-size: 13px; color: var(--warn); margin: -6px 0 12px; font-weight: 600; }
.field { margin-bottom: 12px; }
.field label { display: block; font-size: 12.5px; font-weight: 700; color: var(--sub); margin-bottom: 6px; }
.field textarea {
  width: 100%; min-height: 78px; resize: vertical; padding: 12px 14px;
  border: 1.5px solid var(--line-2); border-radius: var(--radius-sm); background: var(--surface-2);
  color: var(--ink); font-family: inherit; font-size: 14.5px; line-height: 1.6;
}
.field textarea:focus { outline: none; border-color: var(--accent); background: var(--surface); }
.save-row { display: flex; align-items: center; gap: 12px; padding: 4px 24px 20px; }
.saved-tag { font-size: 12.5px; color: var(--good); font-weight: 700; opacity: 0; transition: opacity .3s; display: inline-flex; align-items: center; gap: 5px; }
.saved-tag.show { opacity: 1; }

/* ---------- 참고자료 ---------- */
.reflist { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 18px; }
.ref-btn { display: inline-flex; align-items: center; gap: 8px; padding: 11px 16px; border-radius: var(--radius-sm); border: 1.5px solid var(--line-2); background: var(--surface); color: var(--ink); font-weight: 700; font-size: 13.5px; }
.ref-btn:hover { border-color: var(--accent); color: var(--accent); }

/* ---------- 하단 내비 ---------- */
.navbar {
  position: sticky; bottom: 0; display: flex; align-items: center; gap: 14px;
  padding: 14px 28px; border-top: 1px solid var(--line);
  background: color-mix(in srgb, var(--surface) 88%, transparent); backdrop-filter: blur(8px);
}
.navbar .nx-info { flex: 1; min-width: 0; text-align: center; }
.navbar .nx-info .lbl { font-size: 11px; color: var(--faint); font-weight: 700; letter-spacing: .04em; }
.navbar .nx-info .val { font-size: 13.5px; color: var(--ink); font-weight: 700; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.btn {
  border: none; padding: 12px 22px; border-radius: 11px; font-weight: 800; font-size: 14px;
  display: inline-flex; align-items: center; gap: 8px;
}
.btn.primary { background: var(--accent); color: var(--accent-ink); box-shadow: var(--shadow); }
.btn.primary:hover { filter: brightness(1.06); }
.btn.ghost { background: var(--surface); border: 1.5px solid var(--line-2); color: var(--sub); }
.btn.ghost:hover { border-color: var(--accent); color: var(--accent); }
.btn:disabled { opacity: .4; cursor: not-allowed; }

/* ---------- 모달(참고자료 iframe) ---------- */
.modal { position: fixed; inset: 0; z-index: 50; display: none; }
.modal.open { display: block; }
.modal-bg { position: absolute; inset: 0; background: rgba(6,10,18,.62); backdrop-filter: blur(3px); }
.modal-panel {
  position: absolute; inset: 4% 4%; background: var(--surface); border-radius: var(--radius);
  box-shadow: var(--shadow-lg); display: flex; flex-direction: column; overflow: hidden;
}
.modal-head { display: flex; align-items: center; gap: 12px; padding: 13px 18px; border-bottom: 1px solid var(--line); }
.modal-head .mt { font-weight: 800; font-size: 14.5px; flex: 1; }
.modal-head .mx { border: none; background: var(--surface-2); width: 34px; height: 34px; border-radius: 9px; font-size: 17px; color: var(--sub); }
.modal-head .mx:hover { background: var(--bad-soft); color: var(--bad); }
.modal iframe { flex: 1; border: none; background: #fff; }

/* ---------- 완료 화면 ---------- */
.done-card { text-align: center; padding: 60px 30px; }
.done-card .big { font-size: 54px; }
.done-card h1 { font-size: 26px; margin: 14px 0 6px; }
.done-card p { color: var(--sub); }

/* ---------- 토스트 ---------- */
.toast { position: fixed; bottom: 90px; left: 50%; transform: translateX(-50%) translateY(20px); background: var(--ink); color: var(--surface); padding: 11px 20px; border-radius: 10px; font-weight: 700; font-size: 13.5px; opacity: 0; transition: all .3s; pointer-events: none; z-index: 60; }
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ---------- 반응형 ---------- */
.menu-toggle { display: none; }
@media (max-width: 900px) {
  .app { grid-template-columns: 1fr; }
  .side { position: fixed; z-index: 40; width: 84%; max-width: 340px; height: 100vh; transform: translateX(-100%); transition: transform .25s; box-shadow: var(--shadow-lg); }
  .side.open { transform: translateX(0); }
  .menu-toggle { display: inline-grid; place-items: center; width: 38px; height: 38px; border-radius: 9px; border: 1px solid var(--line-2); background: var(--surface); color: var(--ink); font-size: 18px; }
  .stage { padding: 24px 16px 90px; }
  .step-hd h1 { font-size: 23px; }
}