:root {
  --pri: #2563eb; --pri-2: #1e40af; --ok: #16a34a; --bad: #dc2626; --warn: #d97706;
  --bg: #f8fafc; --card: #fff; --text: #1e293b; --muted: #64748b; --line: #e2e8f0; --soft: #eff6ff;
  --r: 14px;
  --safe-top: env(safe-area-inset-top, 0px);
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #0f172a; --card: #1e293b; --text: #e2e8f0; --muted: #94a3b8; --line: #334155; --soft: #1e3a8a55; }
}
* { box-sizing: border-box; }
body {
  margin: 0; background: var(--bg); color: var(--text);
  font: 16px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, "Malgun Gothic", "Apple SD Gothic Neo", sans-serif;
  -webkit-tap-highlight-color: transparent;
}
[lang="ko"] { word-break: keep-all; }
a { color: inherit; text-decoration: none; }
button, input { font: inherit; color: inherit; }
button { cursor: pointer; }

.top {
  position: sticky; top: 0; z-index: 5; display: flex; justify-content: space-between; align-items: center;
  padding: 10px 16px; background: var(--pri); color: #fff;
  padding-top: calc(10px + var(--safe-top)); /* app Android/iPhone tràn viền: chừa chỗ thanh trạng thái */
}
.brand { font-weight: 700; font-size: 1.15em; }
.brand span { background: #fff; color: var(--pri); border-radius: 8px; padding: 0 6px; margin-right: 4px; }
main { max-width: 640px; margin: 0 auto; padding: 16px 16px 48px; }

.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--r); padding: 16px; margin-bottom: 12px; }
.btn {
  display: inline-block; border: 0; border-radius: 10px; padding: 10px 16px; font-weight: 600;
  background: var(--pri); color: #fff; text-align: center;
}
.btn:active { transform: scale(.98); }
.btn.ghost { background: transparent; border: 1px solid var(--line); color: var(--text); }
.btn.block { display: block; width: 100%; margin: 4px 0 14px; }
.btn.ai { background: linear-gradient(90deg, #7c3aed, var(--pri)); }
.chip { border: 1px solid currentColor; background: transparent; border-radius: 999px; padding: 2px 10px; font-size: .85em; }
.link { background: none; border: 0; color: var(--pri); cursor: pointer; padding: 6px; }
.row { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 12px; }
.muted, .empty { color: var(--muted); }
.empty { text-align: center; padding: 40px 0; }
.back { display: inline-block; color: var(--pri); margin-bottom: 8px; }
.sec { font-size: 1.1em; margin: 20px 0 10px; }

/* Dashboard */
.stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; text-align: center; }
.stats b { display: block; font-size: 1.4em; }
.stats span { font-size: .8em; color: var(--muted); }
.bar { grid-column: 1 / -1; height: 10px; border-radius: 99px; background: var(--line); overflow: hidden; margin-top: 4px; }
.bar i { display: block; height: 100%; background: var(--ok); transition: width .4s; }
.cta { display: block; font-weight: 600; color: var(--pri); background: var(--soft); }
.cta.warn { color: var(--warn); border-color: var(--warn); }
.cta.ok { color: var(--ok); }
.lessons { list-style: none; padding: 0; margin: 0; }
.lesson { display: flex; align-items: center; gap: 12px; padding: 12px; margin-bottom: 8px;
  background: var(--card); border: 1px solid var(--line); border-radius: var(--r); }
.lesson .num { flex: none; width: 36px; height: 36px; border-radius: 50%; display: grid; place-items: center;
  font-weight: 700; background: var(--line); color: var(--muted); }
.lesson.done .num { background: var(--ok); color: #fff; }
.lesson.done { border-color: var(--ok); }
.lesson .t { flex: 1; display: flex; flex-direction: column; }
.lesson small { color: var(--muted); }
.score { color: var(--muted); font-size: .9em; }
.tools { display: flex; justify-content: center; gap: 16px; margin-top: 24px; font-size: .9em; }

/* Lesson detail */
.title { margin: 0 0 12px; font-size: 1.6em; display: flex; flex-direction: column; }
.title small { font-size: .5em; color: var(--muted); font-weight: 500; }
.tabs { position: sticky; top: calc(52px + var(--safe-top)); z-index: 4; display: grid; grid-template-columns: repeat(6, 1fr);
  background: var(--bg); border-bottom: 1px solid var(--line); margin: 0 -16px 14px; padding: 0 8px; }
.tabs a { text-align: center; padding: 8px 0; font-size: .72em; white-space: nowrap; border-bottom: 3px solid transparent; color: var(--muted); }
.tabs a small { display: block; font-size: .8em; }
.tabs a.on { color: var(--pri); border-color: var(--pri); font-weight: 600; }

.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 10px; }
.word { background: var(--card); border: 1px solid var(--line); border-radius: var(--r); padding: 12px;
  display: flex; flex-direction: column; gap: 2px; cursor: pointer; }
.word b { font-size: 1.5em; }
.word i, .word small { color: var(--muted); font-size: .85em; }
.word .chip { margin-top: 8px; align-self: flex-start; color: var(--muted); }
.word.known { border-color: var(--ok); }
.word.learning { border-color: var(--warn); }
.chip.on { color: var(--ok); }

.gram h3 { margin: 0 0 6px; color: var(--pri); }
.gram p { margin: 0 0 10px; }
.ex { display: flex; gap: 10px; align-items: center; background: var(--soft); border-radius: 10px; padding: 10px; }
.ex div { display: flex; flex-direction: column; }
.ex span { color: var(--muted); font-size: .9em; }
.play { flex: none; width: 38px; height: 38px; border-radius: 50%; border: 0; background: var(--pri); color: #fff; }

.ctx { margin: 0 0 10px; color: var(--muted); }
.line { display: flex; gap: 10px; padding: 10px; border-radius: 10px; cursor: pointer; transition: background .2s; }
.line.b { flex-direction: row-reverse; text-align: right; }
.line.on { background: var(--soft); outline: 2px solid var(--pri); }
.line .who { flex: none; width: 44px; height: 44px; border-radius: 50%; display: grid; place-items: center;
  font-size: .8em; font-weight: 700; background: var(--pri); color: #fff; }
.line.b .who { background: #7c3aed; }
.line p { margin: 0; display: flex; flex-direction: column; }
.vi { color: var(--muted); font-size: .9em; }
.hide-vi .vi { display: none; }

.q { border: 1px solid var(--line); }
.q legend { font-weight: 600; padding: 0 4px; }
.q.right { border-color: var(--ok); }
.q.wrong { border-color: var(--bad); }
.fb { margin: 8px 0 0; min-height: 0; }
.q.right .fb { color: var(--ok); }
.q.wrong .fb { color: var(--bad); }
.opts { display: grid; gap: 6px; }
.opt { display: flex; gap: 8px; align-items: center; padding: 8px 10px; border: 1px solid var(--line); border-radius: 10px; cursor: pointer; }
.opt:has(input:checked) { border-color: var(--pri); background: var(--soft); }
.fill { width: 100%; padding: 10px; border: 1px solid var(--line); border-radius: 10px; background: var(--bg); }
.ans, .pool { display: flex; flex-wrap: wrap; gap: 6px; min-height: 44px; padding: 6px; border-radius: 10px; }
.ans { border: 2px dashed var(--line); margin-bottom: 8px; }
.tok { border: 1px solid var(--pri); background: var(--soft); border-radius: 8px; padding: 6px 12px; }
.result { display: flex; flex-direction: column; gap: 8px; align-items: center; text-align: center; margin-top: 12px; }
.result b { font-size: 1.6em; }
.result.ok b { color: var(--ok); }

/* Flashcard */
.flash { background: var(--card); border: 1px solid var(--line); border-radius: 20px; min-height: 260px;
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 6px; padding: 24px; cursor: pointer; text-align: center; }
.flash > b { font-size: 2.6em; }
.backside { display: none; flex-direction: column; gap: 4px; }
.backside i { color: var(--muted); }
.backside span { font-size: 1.3em; font-weight: 600; }
.backside small { color: var(--muted); }
.flash.flipped .backside { display: flex; }
.flash.flipped .hint { display: none; }
.hint { color: var(--muted); font-size: .85em; }
.grade { margin-top: 14px; display: none; }
.flash.flipped + .grade { display: grid; grid-template-columns: 1fr 1fr; }
.btn.bad { background: var(--bad); }
.btn.good { background: var(--ok); }
.tag { border: 1px solid var(--line); border-radius: 6px; padding: 0 6px; }
.done-box { text-align: center; padding: 32px 16px; }
.done-box b { font-size: 1.6em; }

.toast { position: fixed; left: 50%; bottom: 24px; transform: translateX(-50%); max-width: calc(100% - 32px);
  background: #111827; color: #fff; padding: 10px 16px; border-radius: 10px; z-index: 10; animation: up .2s; }
@keyframes up { from { opacity: 0; transform: translate(-50%, 10px); } }

/* ---- Cấu trúc bài kiểu Minna ---- */
main { padding-bottom: calc(48px + env(safe-area-inset-bottom)); }
.sec small, .grp small { color: var(--muted); font-weight: 400; font-size: .75em; margin-left: 4px; }
.grp { font-size: 1em; margin: 18px 0 8px; color: var(--pri); }
.btn.sm { padding: 6px 12px; font-size: .9em; }
.cta.next { color: #fff; background: var(--pri); border-color: var(--pri); }
.badge { align-self: flex-start; font-style: normal; font-size: .45em; margin-top: 6px; padding: 2px 8px;
  border-radius: 99px; border: 1px solid var(--line); color: var(--muted); }
.badge.ok { color: var(--ok); border-color: var(--ok); }
.next-tab { margin-top: 20px; }
.intro { background: var(--soft); }

.patterns h3 { margin: 0 0 8px; font-size: 1em; color: var(--pri); }
.patterns ol { margin: 0; padding-left: 22px; }
.patterns li { padding: 6px 0; cursor: pointer; }
.patterns li span, .drow span { display: block; color: var(--muted); font-size: .88em; }
.gram h3 { display: flex; gap: 8px; align-items: baseline; }
.gi { flex: none; width: 24px; height: 24px; border-radius: 50%; background: var(--pri); color: #fff;
  font-size: .75em; display: grid; place-items: center; }
.exp { white-space: pre-line; }
.ex + .ex { margin-top: 8px; }

.drill h3 { margin: 0 0 6px; font-size: 1em; color: var(--pri); }
.drow { padding: 10px 4px; border-top: 1px solid var(--line); cursor: pointer; }
.drow:first-of-type { border-top: 0; }
.drow:active { background: var(--soft); }

.play.big { width: 52px; height: 52px; font-size: 1.2em; display: block; margin: 4px 0 10px; }
.q + .q { margin-top: 0; }
.q .btn.sm { margin-top: 8px; }
.opt { min-height: 44px; }
.result.fail b { color: var(--bad); }
.word small[lang="ko"] { color: var(--pri); }

@media (max-width: 360px) {
  .grid { grid-template-columns: 1fr 1fr; }
  .word b { font-size: 1.3em; }
}

/* ---- Đề ôn tập ---- */
.lesson.test { background: var(--soft); border-style: dashed; }
.lesson.test .num { background: transparent; font-size: 1.2em; }
.lesson.test.done { border-style: solid; }
.chips { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 14px; }
.chips .chip { color: var(--pri); padding: 4px 12px; }

/* ---- Thi thử TOPIK I ---- */
.timer { position: sticky; top: calc(46px + var(--safe-top)); z-index: 4; display: flex; justify-content: space-between; gap: 8px;
  background: var(--bg); border-bottom: 1px solid var(--line); margin: 0 -16px 8px; padding: 8px 16px;
  font-weight: 600; font-variant-numeric: tabular-nums; }
.timer.low #clock { color: var(--bad); }
#answered { color: var(--muted); font-weight: 400; }
.guide { margin: 18px 0 8px; }
.guide small { display: block; color: var(--muted); font-size: .85em; }
.passage { white-space: pre-line; line-height: 1.7; }
.passage.box { border: 2px solid var(--line); border-radius: 10px; padding: 12px; background: var(--soft); }
.tq { border: 0; border-top: 1px solid var(--line); margin: 12px 0 0; padding: 10px 0 0; }
.item > .listen + .script + .tq, .item > .passage + .tq { border-top: 0; }
.tq legend { white-space: pre-line; padding: 0; margin-bottom: 6px; }
.tq.right legend { color: var(--ok); }
.tq.wrong legend { color: var(--bad); }
.opt b { color: var(--pri); }
.opt:has(input:disabled) { cursor: default; }
.listen small { font-weight: 400; opacity: .85; margin-left: 4px; }
.listen.on { background: var(--ok); }
.script { display: none; margin: 8px 0 0; padding: 8px 10px; background: var(--soft); border-radius: 10px; font-size: .92em; }
.script p { margin: 2px 0; }
.graded .script { display: block; }
.graded button[type="submit"] { display: none; }
.why { display: block; margin-top: 6px; padding: 8px 10px; border-radius: 10px; background: var(--soft); color: var(--text); font-size: .92em; }

/* ---- Luyện nói ---- */
.spk { display: flex; flex-direction: column; gap: 4px; }
.spk .tgt { font-size: 1.2em; }
.spk .row { margin: 6px 0 0; align-items: center; }
.spk .best { margin-left: auto; color: var(--muted); font-size: .85em; }
.btn.mic.rec { background: var(--bad); animation: pulse 1s infinite; }
@keyframes pulse { 50% { opacity: .6; } }
.heard p { margin: 4px 0; }
.marks { font-size: 1.4em; letter-spacing: 1px; }
.mk.ok { color: var(--ok); }
.mk.near { color: var(--warn); }
.mk.bad, .mk.miss { color: var(--bad); }
.mk.miss { text-decoration: line-through; opacity: .7; }
.sc { font-size: 1.2em; }
.sc.ok { color: var(--ok); } .sc.near { color: var(--warn); } .sc.bad { color: var(--bad); }
.tip { background: var(--soft); border-radius: 10px; padding: 8px 10px; font-size: .92em; }
.setup { border-color: var(--warn); }
.setup p { margin: 6px 0 10px; }
.setup .bar { margin: 10px 0 4px; }

/* ---- Phân tích ---- */
.more { grid-column: 1 / -1; color: var(--pri); font-size: .9em; margin-top: 4px; }
.card h3 { font-size: 1em; margin: 14px 0 6px; }
.card h3:first-child { margin-top: 0; }
.card h3 small { color: var(--muted); font-weight: 400; }
.todo, .plain, .errs { margin: 0; padding-left: 20px; }
.todo li, .plain li { padding: 4px 0; }
.todo a, .plain a { color: var(--pri); }
.errs li { padding: 6px 0; }
.errs small { color: var(--muted); }
.errs span { display: block; color: var(--muted); font-size: .88em; }
[hidden] { display: none !important; }

/* ---- Trợ lý hội thoại ---- */
.seg { display: grid; grid-template-columns: 1fr 1fr; border: 1px solid var(--line); border-radius: 10px; overflow: hidden; margin-bottom: 12px; }
.seg a { text-align: center; padding: 9px 4px; font-size: .9em; color: var(--muted); }
.seg a.on { background: var(--pri); color: #fff; font-weight: 600; }
.chat { display: flex; flex-direction: column; gap: 8px; margin-bottom: 12px; }
.msg { max-width: 86%; padding: 8px 12px; border-radius: 14px; position: relative; display: flex; flex-direction: column; }
.msg p { margin: 0; font-size: 1.05em; }
.msg small { font-size: .75em; color: var(--muted); }
.msg.ai { align-self: flex-start; background: var(--card); border: 1px solid var(--line); border-bottom-left-radius: 4px; padding-right: 44px; }
.msg.me { align-self: flex-end; background: var(--pri); color: #fff; border-bottom-right-radius: 4px; }
.msg.me .vi, .msg.me small { color: #dbeafe; }
.msg .play.sm { position: absolute; right: 6px; top: 6px; width: 30px; height: 30px; font-size: .75em; }
.msg.typing { color: var(--muted); }
.msg .sc { align-self: flex-end; font-size: .95em; }
.msg.me .mk.ok { color: #bbf7d0; } .msg.me .mk.near { color: #fde68a; } .msg.me .mk.bad, .msg.me .mk.miss { color: #fecaca; }
.fix { margin-top: 6px; padding: 6px 8px; border-radius: 8px; background: var(--card); color: var(--text); font-size: .9em; display: flex; flex-direction: column; }
.fix span { color: var(--muted); font-size: .92em; }
.sug { display: flex; flex-wrap: wrap; gap: 6px; align-items: center; }
.sug small { width: 100%; }
.sug .chip { color: var(--pri); padding: 6px 12px; text-align: left; }
.composer { position: sticky; bottom: 0; z-index: 3; display: flex; gap: 6px; background: var(--bg);
  border-top: 1px solid var(--line); margin: 0 -16px; padding: 8px 16px calc(8px + env(safe-area-inset-bottom)); }
.composer input { flex: 1; min-width: 0; padding: 10px; border: 1px solid var(--line); border-radius: 10px; background: var(--card); }
.composer .mic { padding: 10px 12px; }
.err { border-color: var(--bad); color: var(--bad); }
.turn { border-color: var(--pri); display: flex; flex-direction: column; gap: 4px; }
.turn .row { margin: 6px 0 0; }
.turn .hint { margin: 2px 0; font-size: 1.1em; }
.setup label { display: flex; flex-direction: column; gap: 4px; margin: 8px 0; font-size: .9em; }
.setup input { padding: 10px; border: 1px solid var(--line); border-radius: 10px; background: var(--bg); }
.chips .chip.on, .role .chip.on { background: var(--pri); border-color: var(--pri); color: #fff; }
.role { align-items: center; }
s[lang="ko"] { color: var(--muted); }

/* ---- Phụ lục ---- */
.tbl-wrap { overflow-x: auto; margin: 8px 0; }
.tbl { width: 100%; border-collapse: collapse; font-size: .92em; }
.tbl th, .tbl td { border-bottom: 1px solid var(--line); padding: 6px 6px; text-align: left; vertical-align: top; }
.tbl th { color: var(--muted); font-weight: 600; font-size: .9em; }
.ko { cursor: pointer; font-weight: 600; }
.ko:active { color: var(--pri); }
.card h4 { margin: 12px 0 2px; font-size: .95em; color: var(--pri); }
.conj-form { display: flex; gap: 6px; margin-bottom: 8px; }
.conj-form input { flex: 1; min-width: 0; padding: 10px; border: 1px solid var(--line); border-radius: 10px; background: var(--bg); }
.refs { margin: -4px 0 10px; }
.refs .chip { font-size: .8em; }
.axq-q { margin: 0 0 8px; font-weight: 600; }
button.opt { width: 100%; text-align: left; background: var(--card); font-size: 1em; }
.opt.pick-ok { border-color: var(--ok); background: #dcfce7; color: #14532d; }
.opt.pick-bad { border-color: var(--bad); background: #fee2e2; color: #7f1d1d; }
.ax-score { text-align: center; font-weight: 600; }
.tbl th { word-break: keep-all; }
.tbl .chip { white-space: nowrap; }

.pt { border-top: 1px solid var(--line); padding: 10px 0; }
.pt:first-of-type { border-top: 0; }
.pt p { margin: 4px 0 0; }
.pt-k { font-size: 1.15em; margin-right: 6px; }
.pt .chip { font-size: .75em; padding: 1px 8px; color: var(--pri); }

.topic-nav .chip { font-size: .8em; padding: 4px 10px; color: var(--pri); background: var(--card); }
.ok-mark { color: var(--ok); font-weight: 700; }
[id^="tp-"] { scroll-margin-top: calc(60px + var(--safe-top)); }

.gfilter .chip { color: var(--pri); }
.gsearch { flex: 1; min-width: 0; padding: 10px; border: 1px solid var(--line); border-radius: 10px; background: var(--bg); }
.gcount { align-self: center; white-space: nowrap; font-size: .85em; }
.tag.lv1 { color: var(--ok); border-color: var(--ok); }
.tag.lv2 { color: var(--pri); border-color: var(--pri); }
.tag.lv3 { color: var(--warn); border-color: var(--warn); }
.tag.lv4 { color: #7c3aed; border-color: #7c3aed; }
.tag.lv5 { color: var(--bad); border-color: var(--bad); }
.lv-head { list-style: none; margin: 18px 0 8px; font-weight: 700; color: var(--pri); font-size: .95em; }
.lv-head:first-child { margin-top: 0; }

/* ---- ⚙️ Nhắc từ vựng (widget + thông báo) ---- */
.rm h3 { margin: 16px 0 6px; font-size: 1em; }
.rm h3:first-child { margin-top: 0; }
.rm .opt { align-items: flex-start; gap: 10px; margin-bottom: 6px; }
.rm .opt input { margin-top: 4px; width: 18px; height: 18px; accent-color: var(--pri); flex: none; }
.rm .opt span { flex: 1; }
.rm .opt small { display: block; color: var(--muted); font-size: .82em; }
.rm .opt.sel { align-items: center; }
.rm .opt.sel span { flex: none; }
.rm select { font: inherit; padding: 4px 8px; border: 1px solid var(--line); border-radius: 8px; background: var(--card); color: var(--text); }
.rm .btn { margin: 10px 0 4px; }
.small { font-size: .85em; }
.rm-now { display: flex; flex-direction: column; gap: 2px; background: linear-gradient(135deg, var(--pri), var(--pri-2)); color: #fff; border: 0; }
.rm-now .muted { color: #ffffffcc; }
.rm-now b { font-size: 1.8em; }
.rm-now i { opacity: .8; }
.rm-now .row { margin: 10px 0 0; }
.rm-now .btn { background: #ffffff2e; }