:root {
  --bg: #f6f6f4;
  --card: #fff;
  --fg: #1b1b19;
  --sub: #66665f;
  --mute: #a2a29b;
  --line: #e5e4df;
  --acc: #2f55d4;
  --acc-bg: #edf1fd;
  --ok: #178a55;
  --ok-bg: #e7f5ed;
  --bad: #d4433a;
  --bad-bg: #fcebea;
  --mark: #fff0a0;
  --r: 16px;
  --fs: 18px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111112;
    --card: #1a1a1c;
    --fg: #ececea;
    --sub: #a3a39d;
    --mute: #6b6b67;
    --line: #2b2b2e;
    --acc: #8aa4ff;
    --acc-bg: #1c2340;
    --ok: #45cf8f;
    --ok-bg: #11271d;
    --bad: #ff6d63;
    --bad-bg: #321719;
    --mark: #5b4e14;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; }
body {
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.6 "Pretendard Variable", Pretendard, -apple-system, BlinkMacSystemFont, system-ui, "Apple SD Gothic Neo", "Malgun Gothic", sans-serif;
  -webkit-tap-highlight-color: transparent;
  word-break: keep-all;
  overflow-wrap: break-word;
  min-height: 100dvh;
}
#app { max-width: 720px; margin: 0 auto; padding: 0 16px calc(108px + env(safe-area-inset-bottom)); }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
a { color: inherit; text-decoration: none; }
:focus-visible { outline: 2px solid var(--acc); outline-offset: 2px; }
.ic { width: 22px; height: 22px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; flex: none; }
mark { background: var(--mark); color: inherit; padding: 0 .12em; border-radius: 3px; }
u { text-underline-offset: .22em; text-decoration-thickness: 1.5px; }

/* header */
.head { position: sticky; top: 0; z-index: 5; background: var(--bg); margin: 0 -16px; padding: 0 16px; }
.top { display: flex; align-items: center; gap: 4px; height: 56px; margin: 0 -8px; padding-top: env(safe-area-inset-top); box-sizing: content-box; }
.top h1 { flex: 1; min-width: 0; font-size: 17px; font-weight: 650; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.top.home { margin: 0; height: 72px; }
.top.home h1 { font-size: 26px; font-weight: 750; letter-spacing: -.02em; }
.tools { display: flex; gap: 2px; }
.ib { width: 40px; height: 40px; display: grid; place-items: center; border-radius: 10px; color: var(--sub); flex: none; }
.ib.txt { width: auto; min-width: 40px; padding: 0 10px; font-size: 13px; font-weight: 700; letter-spacing: .02em; }
.ib:active { background: var(--line); }
.ib.on { color: var(--acc); }
@media (hover: hover) { .ib:hover { background: var(--line); } }

.tabs { display: flex; gap: 4px; padding: 2px 0 12px; }
.tabs a { flex: 1; text-align: center; padding: 8px 0; border-radius: 10px; color: var(--sub); font-weight: 600; font-size: 15px; }
.tabs a small { margin-left: 5px; font-size: 12px; font-weight: 500; color: var(--mute); }
.tabs a.on { background: var(--card); color: var(--fg); box-shadow: 0 0 0 1px var(--line); }

/* home */
.grp { margin: 4px 0 26px; }
.grp h2 { font-size: 13px; font-weight: 600; color: var(--sub); padding: 0 4px 8px; }
.list { background: var(--card); border: 1px solid var(--line); border-radius: var(--r); overflow: hidden; }
.row { display: block; padding: 14px 16px; }
.row + .row { border-top: 1px solid var(--line); }
.row:active { background: var(--bg); }
@media (hover: hover) { .row:hover { background: var(--bg); } }
.row .t { font-weight: 600; font-size: 16px; }
.row .m { display: flex; align-items: center; gap: 12px; margin-top: 2px; font-size: 13px; color: var(--mute); }
.row .m span { flex: 1; min-width: 0; }
.row .pbar { flex: none; width: 56px; }
.empty { text-align: center; color: var(--mute); padding: 80px 0; font-family: ui-monospace, monospace; font-size: 14px; }
.err { white-space: pre-wrap; font: 13px/1.6 ui-monospace, Consolas, monospace; color: var(--bad); background: var(--bad-bg); padding: 16px; border-radius: 12px; }

.pbar { display: block; height: 4px; background: var(--line); border-radius: 4px; overflow: hidden; flex: 1; }
.pbar b { display: block; height: 100%; background: var(--acc); border-radius: 4px; transition: width .3s; }

/* passage */
.psg { background: var(--card); border: 1px solid var(--line); border-radius: var(--r); padding: 22px 20px; margin-bottom: 12px; font-size: var(--fs); line-height: 1.8; word-break: normal; }
.psg h2 { font-size: .78em; font-weight: 650; color: var(--sub); margin-bottom: .9em; }
.psg p + p { margin-top: 1em; }
.src { margin-top: 1.2em; font-size: .72em; color: var(--mute); text-align: right; }
.u.k { cursor: pointer; }
.u .en { border-radius: 4px; transition: background .15s, filter .2s; }
.u .ko { display: none; font-size: .84em; line-height: 1.65; color: var(--sub); word-break: keep-all; margin: .15em 0 .55em; }
.u.open, .m-both .u, .m-ko .u, .lines .u { display: block; }
.u.open .ko, .m-both .u .ko, .m-ko .u .ko { display: block; }
.m-en .u.open .en { background: var(--acc-bg); }
.m-ko .u.k { display: flex; flex-direction: column-reverse; }
.m-ko .u.k .ko { color: var(--fg); font-size: .9em; margin: 0 0 .1em; }
.m-ko .u.k:not(.open) .en { filter: blur(5px); opacity: .5; user-select: none; }
.m-both .u + .u, .m-ko .u + .u { margin-top: .3em; }
.lines .u .ko { margin-top: 0; }

/* sheet */
.sheet { position: fixed; inset: 0; z-index: 20; }
.sheet:not(.in) { pointer-events: none; }
.scrim { position: absolute; inset: 0; background: rgba(0, 0, 0, .35); opacity: 0; transition: opacity .25s; }
.panel { position: absolute; left: 0; right: 0; bottom: 0; max-width: 720px; margin: 0 auto; max-height: 90dvh; overflow: auto; overscroll-behavior: contain; background: var(--bg); border-radius: 20px 20px 0 0; padding: 0 12px calc(20px + env(safe-area-inset-bottom)); transform: translateY(100%); transition: transform .28s cubic-bezier(.2, .8, .2, 1); }
.sheet.in .scrim { opacity: 1; }
.sheet.in .panel { transform: none; }
.ph { position: sticky; top: 0; display: flex; align-items: center; padding: 8px 0; background: var(--bg); }
.ph span { flex: 1; }

/* quiz */
.qtop { display: flex; align-items: center; gap: 10px; height: 44px; margin-bottom: 10px; }
.cnt { min-width: 48px; font-weight: 700; font-variant-numeric: tabular-nums; }
.cnt small { font-size: 13px; font-weight: 500; color: var(--mute); }
.qcard { background: var(--card); border: 1.5px solid var(--line); border-radius: var(--r); padding: 20px 18px; transition: border-color .2s; }
.qcard.ok { border-color: var(--ok); }
.qcard.bad { border-color: var(--bad); }
.prompt { font-weight: 650; font-size: 16.5px; line-height: 1.6; margin-bottom: 16px; }
.ctx { font-size: 16px; line-height: 1.8; padding: 14px 16px; border-radius: 12px; background: var(--bg); margin-bottom: 16px; word-break: normal; }

.opts { display: grid; gap: 8px; }
.opt { display: flex; align-items: flex-start; gap: 10px; text-align: left; padding: 12px 14px; border: 1.5px solid var(--line); border-radius: 12px; line-height: 1.55; transition: background .12s, border-color .12s; }
.opt .n { flex: none; color: var(--mute); }
.opt:disabled { cursor: default; }
.opt.sel { border-color: var(--acc); background: var(--acc-bg); }
.opt.sel .n { color: var(--acc); }
.opt.ok { border-color: var(--ok); background: var(--ok-bg); }
.opt.ok .n { color: var(--ok); }
.opt.bad { border-color: var(--bad); background: var(--bad-bg); }
.opt.bad .n { color: var(--bad); }
.ox { grid-template-columns: 1fr 1fr; }
.ox .opt { justify-content: center; font-size: 30px; font-weight: 700; padding: 22px 0; }

.inp { width: 100%; font: inherit; font-size: 17px; padding: 12px 14px; border: 1.5px solid var(--line); border-radius: 12px; background: var(--bg); color: var(--fg); outline: none; resize: vertical; }
.inp:focus { border-color: var(--acc); }
.inp.ok { border-color: var(--ok); background: var(--ok-bg); }
.inp.bad { border-color: var(--bad); background: var(--bad-bg); }

.blank { font-size: 17px; line-height: 2.4; word-break: normal; }
.bl { font: inherit; max-width: 100%; padding: 0 .3em; margin: 0 .1em; border: 0; border-bottom: 2px solid var(--acc); border-radius: 6px 6px 0 0; background: var(--acc-bg); color: var(--fg); text-align: center; outline: none; line-height: 1.5; }
.bl:focus { background: var(--card); box-shadow: 0 0 0 1.5px var(--acc) inset; }
.bl.ok { border-color: var(--ok); background: var(--ok-bg); }
.bl.bad { border-color: var(--bad); background: var(--bad-bg); text-decoration: line-through; color: var(--sub); }
.fix { color: var(--ok); font-weight: 700; margin: 0 .3em 0 .1em; }

.ord .slots { min-height: 54px; display: grid; gap: 6px; padding: 8px; border: 1.5px dashed var(--line); border-radius: 12px; margin-bottom: 12px; }
.ord .pool { display: grid; gap: 6px; }
.it { display: flex; gap: 8px; text-align: left; padding: 10px 12px; line-height: 1.55; border: 1.5px solid var(--line); border-radius: 10px; background: var(--card); word-break: normal; }
.it .n { flex: none; color: var(--acc); font-weight: 700; }
.it .grip { flex: none; display: grid; place-items: center; align-self: stretch; width: 30px; margin: -6px 8px -6px -6px; border-radius: 9px; background: var(--bg); color: var(--mute); touch-action: none; cursor: grab; }
.it .grip .ic { width: 18px; height: 18px; }
.it.drag { position: relative; z-index: 2; border-color: var(--acc); box-shadow: 0 8px 22px rgba(0, 0, 0, .18); }
.it.drag .grip { cursor: grabbing; color: var(--acc); }
.ord:not(.chips) .it.used { display: none; }
.chips .slots, .chips .pool { display: flex; flex-wrap: wrap; align-content: flex-start; }
.chips .it { padding: 7px 13px; border-radius: 10px; font-size: 16.5px; }
.chips .it.used { color: transparent; background: var(--line); border-color: transparent; pointer-events: none; }
.it.ok { border-color: var(--ok); background: var(--ok-bg); }
.it.bad { border-color: var(--bad); background: var(--bad-bg); }

.fb { margin-top: 18px; padding-top: 16px; border-top: 1px solid var(--line); }
.verdict { display: inline-grid; place-items: center; width: 30px; height: 30px; border-radius: 50%; color: #fff; }
.verdict .ic { width: 18px; height: 18px; stroke-width: 3; }
.verdict.ok { background: var(--ok); }
.verdict.bad { background: var(--bad); }
.ans { margin-top: 10px; font-weight: 650; color: var(--ok); line-height: 1.6; }
.ans .or { color: var(--mute); font-weight: 400; }
.sol { padding-left: 1.4em; font-weight: 500; }
.sol li { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.exp { margin-top: 10px; color: var(--sub); font-size: 15px; line-height: 1.75; }

/* dock */
.dock { position: fixed; left: 0; right: 0; bottom: 0; z-index: 6; padding: 20px 16px calc(14px + env(safe-area-inset-bottom)); background: linear-gradient(to bottom, transparent, var(--bg) 40%); pointer-events: none; }
.dock .in { display: flex; gap: 10px; max-width: 688px; margin: 0 auto; pointer-events: auto; }
.btn { flex: 1; display: inline-flex; align-items: center; justify-content: center; gap: 8px; height: 54px; padding: 0 20px; border-radius: 15px; font-weight: 650; font-size: 16px; background: var(--card); border: 1.5px solid var(--line); transition: transform .1s, opacity .15s; }
.btn:active { transform: scale(.97); }
.btn:disabled { opacity: .35; }
.btn.primary { background: var(--fg); color: var(--bg); border-color: transparent; }
.btn.sq { flex: none; width: 54px; padding: 0; color: var(--sub); }
.btn.sq.on { color: var(--acc); border-color: var(--acc); }
.btn.ok { color: var(--ok); }
.btn.bad { color: var(--bad); }
.btn .ic { width: 24px; height: 24px; }

/* overview */
.start { text-align: center; padding: 28px 0 8px; }
.big { font-size: 60px; font-weight: 750; letter-spacing: -.03em; line-height: 1.1; font-variant-numeric: tabular-nums; }
.big span { font-size: 26px; font-weight: 600; color: var(--mute); }
.big.fresh { animation: pop .35s cubic-bezier(.2, .9, .3, 1.3); }
@keyframes pop { from { transform: scale(.8); opacity: 0; } }
.dots { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px; margin: 28px 0 0; }
.dots button { width: 40px; height: 40px; border-radius: 50%; background: var(--card); border: 1px solid var(--line); font-size: 14px; font-weight: 600; color: var(--sub); font-variant-numeric: tabular-nums; }
.dots .ok { background: var(--ok-bg); border-color: transparent; color: var(--ok); }
.dots .bad { background: var(--bad-bg); border-color: transparent; color: var(--bad); }

/* cards */
.card { min-height: min(56dvh, 460px); display: flex; flex-direction: column; justify-content: center; gap: 18px; padding: 28px 22px; text-align: center; background: var(--card); border: 1.5px solid var(--line); border-radius: 22px; cursor: pointer; user-select: none; touch-action: pan-y; transition: transform .2s, opacity .16s, border-color .15s; }
.card .f { font-size: 30px; font-weight: 700; line-height: 1.3; letter-spacing: -.01em; }
.card .b { display: none; font-size: 21px; font-weight: 600; line-height: 1.5; }
.card.flip .f { font-size: 19px; color: var(--sub); font-weight: 600; }
.card.flip .b { display: block; }
.card .ex { margin-top: 14px; font-size: 15px; font-weight: 400; color: var(--sub); line-height: 1.65; }
.card[data-lean=ok] { border-color: var(--ok); }
.card[data-lean=bad] { border-color: var(--bad); }

/* 지문 이동 (탭 줄 양끝) */
.tabs .nb { flex: none; width: 40px; display: grid; place-items: center; border-radius: 10px; color: var(--sub); }
.tabs a.nb:active { background: var(--line); }
.tabs .nb.off { opacity: .25; }
.tabs .sp { flex: 1; }
.top h1 button { display: block; width: 100%; padding: 6px 8px; margin: 0 -8px; border-radius: 8px; font: inherit; text-align: left; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.top h1 button:active { background: var(--line); }
.row.cur { background: var(--acc-bg); }
.row.cur .t { color: var(--acc); }

/* 랜덤 학습 지문 선택 */
.top.home .ib { flex: none; margin-right: -4px; }
.gh { display: flex; align-items: center; justify-content: space-between; width: 100%; padding: 0 4px 8px; text-align: left; }
.gh h2 { padding: 0; }
.chk { flex: none; width: 22px; height: 22px; display: grid; place-items: center; border: 1.5px solid var(--mute); border-radius: 50%; color: transparent; transition: background .12s, border-color .12s; }
.chk .ic { width: 14px; height: 14px; stroke-width: 3; }
.on > .chk, .gh.on .chk { background: var(--acc); border-color: var(--acc); color: #fff; }
.row.pk { display: flex; align-items: center; gap: 14px; width: 100%; text-align: left; }
.row.pk .bd { flex: 1; min-width: 0; }
.row.pk.on { background: var(--acc-bg); }
.row.pk.dis { opacity: .4; pointer-events: none; }
.btn .num { font-weight: 700; font-variant-numeric: tabular-nums; }
.btn:disabled .num { display: none; }

/* 문제 화면 */
.qtop .round { display: inline-flex; align-items: center; gap: 2px; font-size: 12px; font-weight: 600; color: var(--mute); }
.qtop .round .ic { width: 13px; height: 13px; }
.from { margin: -2px 4px 8px; font-size: 13px; color: var(--mute); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.btn.sq:disabled { opacity: .3; }

/* 배열 문제: 처음부터 전부 놓여 있음 */
.ord .slots { border: 0; padding: 0; min-height: 0; margin-bottom: 0; }
.chips .it { touch-action: none; cursor: grab; user-select: none; -webkit-user-select: none; }
.chips .it.drag { cursor: grabbing; }
body.dragging { user-select: none; -webkit-user-select: none; cursor: grabbing; }

/* 배열 문제: 선택/취소 도구, 다시 점선 슬롯 */
.ord .slots { border: 1.5px dashed var(--line); padding: 8px; min-height: 54px; margin-bottom: 12px; }
.otool { display: flex; justify-content: flex-end; gap: 2px; margin: -6px -8px 2px 0; }
.otool .ib { width: 36px; height: 36px; }
.otool .ic { width: 20px; height: 20px; }
.it:not(.in) { cursor: pointer; }

/* 랜덤 학습: 유형 칩 */
.kchips { display: flex; flex-wrap: wrap; gap: 6px; margin: 0 0 18px; }
.kc { display: inline-flex; align-items: baseline; gap: 5px; padding: 6px 12px; border: 1.5px solid var(--line); border-radius: 99px; font-size: 14px; font-weight: 600; color: var(--mute); background: var(--card); }
.kc small { font-size: 12px; font-weight: 500; font-variant-numeric: tabular-nums; }
.kc.on { color: var(--acc); border-color: var(--acc); background: var(--acc-bg); }
.kc.z { opacity: .45; }

/* 본문 단어 선택 */
.psg .en { -webkit-user-select: none; user-select: none; -webkit-touch-callout: none; }
.w { border-radius: 4px; cursor: pointer; transition: background .12s; }
@media (hover: hover) { .w:hover { background: var(--line); } }
.w.has { text-decoration: underline dotted var(--acc); text-underline-offset: .2em; text-decoration-thickness: 1.5px; }
.w.sel { background: var(--acc-bg); color: var(--acc); box-shadow: -2px 0 0 var(--acc-bg), 2px 0 0 var(--acc-bg); }
body.lk #app { padding-bottom: calc(var(--lk, 0px) + 24px); }
body.lk .panel { padding-bottom: calc(var(--lk, 0px) + 20px); }

/* 뜻 패널 */
.lookup { position: fixed; left: 0; right: 0; bottom: 0; z-index: 40; max-width: 720px; margin: 0 auto; max-height: 52dvh; overflow: auto; overscroll-behavior: contain; background: var(--card); border: 1px solid var(--line); border-bottom: 0; border-radius: 20px 20px 0 0; box-shadow: 0 -10px 30px rgba(0, 0, 0, .16); padding: 6px 16px calc(12px + env(safe-area-inset-bottom)); }
.lk-h { position: sticky; top: 0; z-index: 1; display: flex; align-items: center; gap: 8px; background: var(--card); padding: 2px 0; }
.lk-t { flex: none; max-width: 62%; font-size: 18px; font-weight: 700; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.lk-tag { flex: 1; font-size: 12px; color: var(--mute); }
.lk-b { display: grid; gap: 8px; padding: 2px 0 10px; }
.lk-g { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; }
.lk-g small { flex: none; width: 34px; font-size: 12px; color: var(--mute); }
.mc { padding: 5px 11px; border: 1.5px solid var(--line); border-radius: 99px; font-size: 15px; color: var(--sub); }
.mc.ctx { color: var(--fg); font-weight: 650; border-color: var(--mute); }
.mc.on { background: var(--acc-bg); border-color: var(--acc); color: var(--acc); }
.lk-hit { display: grid; gap: 2px; }
.lk-hit b { font-size: 17px; }
.lk-hit span { font-size: 13px; color: var(--mute); }
.lk-s { padding-top: 8px; border-top: 1px solid var(--line); font-size: 14px; line-height: 1.65; color: var(--sub); }
.lk-err { font-size: 13px; color: var(--bad); }
.lk-spin { width: 18px; height: 18px; border: 2px solid var(--line); border-top-color: var(--acc); border-radius: 50%; animation: spin .7s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
.lk-f { position: sticky; bottom: -12px; display: flex; gap: 8px; background: var(--card); padding: 8px 0 0; }
.lk-in { flex: 1; min-width: 0; font: inherit; font-size: 16px; padding: 10px 12px; border: 1.5px solid var(--line); border-radius: 12px; background: var(--bg); color: var(--fg); outline: none; }
.lk-in:focus { border-color: var(--acc); }
.lk-bk { flex: none; max-width: 28%; padding: 0 10px; border: 1.5px solid var(--line); border-radius: 12px; font-size: 13px; color: var(--sub); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.btn.lk-sv { flex: none; width: 52px; height: 46px; padding: 0; border-radius: 12px; }
.lk-sv.done { background: var(--ok); }
.toast { position: fixed; left: 50%; bottom: calc(90px + env(safe-area-inset-bottom)); z-index: 70; max-width: 90vw; padding: 10px 16px; border-radius: 99px; background: var(--fg); color: var(--bg); font-size: 14px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; opacity: 0; pointer-events: none; transform: translate(-50%, 10px); transition: opacity .2s, transform .2s; }
.toast.in { opacity: 1; transform: translate(-50%, 0); }
.sheet.over { z-index: 60; }

/* 단어장 */
.ib.txt.off { color: var(--mute); }
.row.bk { width: 100%; text-align: left; }
.wrow { display: block; width: 100%; padding: 14px 4px; border-bottom: 1px solid var(--line); text-align: left; }
.wt { font-size: 17px; font-weight: 650; }
.wm { color: var(--fg); }
.we { margin-top: 2px; font-size: 13px; line-height: 1.55; color: var(--mute); display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.frm { display: grid; gap: 10px; padding: 8px 0 12px; }
.frm input, .frm textarea { width: 100%; font: inherit; font-size: 16px; padding: 12px 14px; border: 1.5px solid var(--line); border-radius: 12px; background: var(--card); color: var(--fg); outline: none; resize: vertical; }
.frm input:focus, .frm textarea:focus { border-color: var(--acc); }
.frm .acts { display: flex; gap: 10px; }
.blank-state { display: grid; place-items: center; padding: 90px 0; color: var(--line); }
.blank-state .ic { width: 56px; height: 56px; }

/* 계정 */
.acct { display: grid; gap: 8px; padding: 14px 4px 18px; text-align: center; justify-items: center; }
.acct b { font-size: 17px; }
.acct span { font-size: 14px; color: var(--sub); }
.acct-st { font-size: 13px; color: var(--ok); }
.acct-st.bad, .acct .lk-err { color: var(--bad); }
.acct .acts { display: flex; gap: 10px; width: 100%; margin-top: 8px; }
.acct > .btn { width: 100%; }

/* 안 푼 문제 칩, 다 풀었을 때 */
.kc.uns.on { color: var(--ok); border-color: var(--ok); background: var(--ok-bg); }
.big.alldone .ic { width: 72px; height: 72px; color: var(--ok); stroke-width: 2.4; }