:root {
  --bg: #f6f5f2;
  --surface: #ffffff;
  --ink: #141414;
  --muted: #6b6b6b;
  --line: #e4e2dd;
  --accent: #141414;
  --accent-ink: #ffffff;
  --highlight: #fff1b8;
  --danger: #b42318;
  --ok: #1a7f37;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(0,0,0,.04), 0 8px 24px rgba(0,0,0,.06);
}
* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans KR", "Noto Sans", sans-serif;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; }
.top {
  display: flex; align-items: center; justify-content: space-between;
  padding: 16px 20px; max-width: 1100px; margin: 0 auto;
}
.brand { font-weight: 800; letter-spacing: .14em; text-decoration: none; font-size: 15px; }
.top .who { display: flex; gap: 12px; align-items: center; color: var(--muted); font-size: 14px; }
.wrap { max-width: 1100px; margin: 0 auto; padding: 8px 16px 64px; }
.narrow { max-width: 440px; margin: 6vh auto 0; }
.card {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  box-shadow: var(--shadow); padding: 24px;
}
h1 { font-size: 28px; line-height: 1.2; margin: 0 0 6px; letter-spacing: -.01em; }
h2 { font-size: 18px; margin: 0 0 12px; }
.sub { color: var(--muted); margin: 0 0 22px; }
label { display: block; font-size: 13px; font-weight: 600; margin: 14px 0 6px; }
input[type=text], input[type=password], input[type=url], textarea {
  width: 100%; padding: 11px 12px; border: 1px solid var(--line); border-radius: 10px;
  font: inherit; background: #fff; color: var(--ink);
}
textarea { min-height: 150px; resize: vertical; font-size: 14px; }
input:focus, textarea:focus { outline: 2px solid var(--ink); outline-offset: -1px; border-color: transparent; }
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 11px 18px; border-radius: 10px; border: 1px solid var(--accent);
  background: var(--accent); color: var(--accent-ink); font: inherit; font-weight: 600;
  cursor: pointer; text-decoration: none;
}
.btn:disabled { opacity: .5; cursor: progress; }
.btn.ghost { background: transparent; color: var(--ink); border-color: var(--line); }
.btn.small { padding: 6px 12px; font-size: 14px; }
.btn.full { width: 100%; margin-top: 20px; }
.linkbtn { background: none; border: 0; padding: 0; color: var(--muted); font: inherit; cursor: pointer; text-decoration: underline; }
.err { color: var(--danger); font-size: 14px; margin-top: 12px; min-height: 1em; }
.okmsg { color: var(--ok); font-size: 14px; }
.hint { color: var(--muted); font-size: 13px; margin-top: 6px; }

.btn.google { width: 100%; background: #fff; }
.or { display: flex; align-items: center; gap: 10px; color: var(--muted); font-size: 13px; margin: 18px 0 2px; }
.or::before, .or::after { content: ""; flex: 1; height: 1px; background: var(--line); }
.roles { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 6px; }
.role {
  border: 1.5px solid var(--line); border-radius: 12px; padding: 18px 14px; background: #fff;
  cursor: pointer; text-align: left; font: inherit; color: var(--ink);
}
.role b { display: block; font-size: 17px; margin-bottom: 2px; }
.role span { color: var(--muted); font-size: 13px; }
.role[aria-pressed=true] { border-color: var(--ink); box-shadow: 0 0 0 1px var(--ink) inset; }
.tabs { display: flex; gap: 4px; background: var(--bg); padding: 4px; border-radius: 10px; margin-bottom: 18px; }
.tabs button { flex: 1; border: 0; background: transparent; padding: 9px; border-radius: 8px; font: inherit; font-weight: 600; color: var(--muted); cursor: pointer; }
.tabs button[aria-selected=true] { background: #fff; color: var(--ink); box-shadow: var(--shadow); }

.grid2 { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 20px; align-items: start; }
@media (max-width: 820px) { .grid2 { grid-template-columns: 1fr; } }
.songs { list-style: none; padding: 0; margin: 0; display: grid; gap: 10px; }
.song {
  display: grid; grid-template-columns: 96px minmax(0, 1fr); gap: 12px; align-items: center;
  background: #fff; border: 1px solid var(--line); border-radius: 12px; padding: 10px;
}
.song img { width: 96px; height: 54px; object-fit: cover; border-radius: 8px; background: var(--line); }
.song .t { font-weight: 600; text-decoration: none; display: block; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.song .m { color: var(--muted); font-size: 13px; }
.song .acts { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 4px; font-size: 13px; }
.empty { color: var(--muted); font-size: 14px; padding: 18px; text-align: center; border: 1px dashed var(--line); border-radius: 12px; }
.share { display: flex; gap: 8px; margin-top: 14px; }
.share input { font-size: 14px; }

/* Lesson player */
.player-layout { display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr); gap: 20px; align-items: start; }
@media (max-width: 900px) { .player-layout { grid-template-columns: 1fr; } }
.video { position: relative; aspect-ratio: 16 / 9; background: #000; border-radius: var(--radius); overflow: hidden; }
.video iframe, .video #player { position: absolute; inset: 0; width: 100%; height: 100%; }
.sticky { position: sticky; top: 12px; }
@media (max-width: 900px) { .sticky { position: sticky; top: 0; z-index: 5; background: var(--bg); padding-top: 8px; } }
.lyrics { max-height: 72vh; overflow-y: auto; padding: 8px; scroll-behavior: smooth; }
@media (max-width: 900px) { .lyrics { max-height: none; } }
.ln { padding: 10px 12px; border-radius: 10px; cursor: pointer; transition: background .15s; }
.ln:hover { background: #f0efeb; }
.ln.active { background: var(--highlight); }
.ln .o { font-size: 19px; font-weight: 600; }
.ln .e { color: var(--muted); font-size: 15px; margin-top: 2px; }
.ln .ts { color: var(--muted); font-size: 11px; font-variant-numeric: tabular-nums; float: right; margin-left: 8px; }
.w { border-radius: 4px; padding: 0 1px; }
.w:hover, .w.on { background: #141414; color: #fff; }
#tip {
  position: fixed; z-index: 50; pointer-events: none; opacity: 0; transform: translate(-50%, -100%);
  background: #141414; color: #fff; padding: 8px 12px; border-radius: 10px; font-size: 14px;
  max-width: 260px; box-shadow: var(--shadow); transition: opacity .12s;
}
#tip.show { opacity: 1; }
#tip small { display: block; opacity: .6; font-size: 11px; text-transform: uppercase; letter-spacing: .08em; }
.banner { background: #fff; border: 1px solid var(--line); border-radius: 12px; padding: 14px 16px; margin: 14px 0; display: flex; gap: 12px; align-items: center; justify-content: space-between; flex-wrap: wrap; }
.sync-bar { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; margin-top: 12px; }
.sync-bar .btn.tap { min-width: 160px; }
.meta { margin: 14px 0 4px; }
.meta h1 { font-size: 22px; }
.loading { color: var(--muted); padding: 40px 0; text-align: center; }