/* ==========================================================================
   English Path — giao diện
   ========================================================================== */
:root {
  --bg: #f7f4ee;
  --surface: #ffffff;
  --surface-2: #f1ede4;
  --ink: #1c2433;
  --muted: #5d6677;
  --line: #e4ded2;
  --accent: #1f3a5f;
  --accent-ink: #ffffff;
  --accent-soft: #e3eaf4;
  --gold: #f6c453;
  --ok: #2f9e6b;
  --ok-soft: #e2f4ea;
  --bad: #c2412d;
  --bad-soft: #fbe6e1;
  --track: #ece7dd;
  --shadow: 0 1px 2px rgba(28, 36, 51, .06), 0 6px 20px rgba(28, 36, 51, .06);

  --A1: #2f9e6b; --A2: #138a8f; --B1: #3366cc; --B2: #7b4fc9; --C1: #c25a1b;

  --radius: 14px;
  --font: "Be Vietnam Pro", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --display: "Fraunces", Georgia, serif;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #11151c; --surface: #19202a; --surface-2: #212a36; --ink: #e8ebf1; --muted: #9aa4b5;
    --line: #2a3442; --accent: #8fb3e8; --accent-ink: #0d1520; --accent-soft: #1f2d42;
    --ok: #4cc28b; --ok-soft: #173326; --bad: #f07a65; --bad-soft: #3a1f1a; --track: #2a3340;
    --shadow: 0 1px 2px rgba(0,0,0,.3), 0 8px 24px rgba(0,0,0,.25);
    --A1: #4cc28b; --A2: #3cc0c4; --B1: #6f9cf0; --B2: #a685e8; --C1: #f0905a;
  }
}
:root[data-theme="dark"] {
  --bg: #11151c; --surface: #19202a; --surface-2: #212a36; --ink: #e8ebf1; --muted: #9aa4b5;
  --line: #2a3442; --accent: #8fb3e8; --accent-ink: #0d1520; --accent-soft: #1f2d42;
  --ok: #4cc28b; --ok-soft: #173326; --bad: #f07a65; --bad-soft: #3a1f1a; --track: #2a3340;
  --shadow: 0 1px 2px rgba(0,0,0,.3), 0 8px 24px rgba(0,0,0,.25);
  --A1: #4cc28b; --A2: #3cc0c4; --B1: #6f9cf0; --B2: #a685e8; --C1: #f0905a;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font: 16px/1.6 var(--font);
  min-height: 100vh; display: flex; flex-direction: column;
}
a { color: var(--accent); text-underline-offset: 3px; }
h1, h2, h3 { line-height: 1.25; margin: 0 0 .4em; }
h1 { font-family: var(--display); font-size: clamp(1.6rem, 3.6vw, 2.3rem); letter-spacing: -.01em; }
h2 { font-size: 1.3rem; }
h3 { font-size: 1.05rem; }
p { margin: 0 0 .8em; }
code { background: var(--surface-2); padding: .1em .35em; border-radius: 5px; font-size: .9em; }
.muted { color: var(--muted); }
.small { font-size: .87rem; }
.center { text-align: center; }
.eyebrow { text-transform: uppercase; letter-spacing: .08em; font-size: .75rem; font-weight: 600; color: var(--muted); margin-bottom: .4em; }
.lead { font-size: 1.1rem; color: var(--muted); max-width: 60ch; }
.row { display: flex; gap: .75rem; align-items: center; flex-wrap: wrap; }
.row.between { justify-content: space-between; }
.row.center { justify-content: center; }
.row.gap-s { gap: .4rem; }
.wrap { flex-wrap: wrap; }

/* ---------------- top bar ---------------- */
.topbar {
  position: sticky; top: 0; z-index: 20;
  display: flex; align-items: center; gap: 1rem;
  padding: .65rem max(16px, calc((100vw - 1100px) / 2));
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(10px); border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: .55rem; text-decoration: none; color: var(--ink); font-weight: 500; font-size: 1.05rem; }
.brand b { font-weight: 700; }
.logo {
  width: 32px; height: 32px; border-radius: 9px; display: grid; place-items: center;
  background: #1f3a5f; color: var(--gold); font-family: var(--display); font-weight: 700; font-size: 1.15rem;
}
.nav { display: flex; gap: .2rem; margin-left: auto; }
.nav a {
  text-decoration: none; color: var(--muted); padding: .45rem .75rem; border-radius: 10px;
  font-size: .92rem; font-weight: 500; display: flex; align-items: center; gap: .35rem;
}
.nav a span { font-size: .95rem; }
.nav a:hover { background: var(--surface-2); color: var(--ink); }
.nav a.active { background: var(--accent-soft); color: var(--accent); }
.icon-btn { border: 1px solid var(--line); background: var(--surface); border-radius: 10px; width: 38px; height: 38px; cursor: pointer; font-size: 1rem; }

main { width: 100%; max-width: 1100px; margin: 0 auto; padding: 1.6rem 16px 3rem; flex: 1; outline: none; }
main > section, main > .card, main > .grid2, main > nav { margin-bottom: 1.25rem; }
.foot { text-align: center; color: var(--muted); font-size: .8rem; padding: 1.5rem 16px 2rem; border-top: 1px solid var(--line); }
.foot p { max-width: 70ch; margin: 0 auto; }

/* ---------------- building blocks ---------------- */
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 1.15rem 1.25rem; box-shadow: var(--shadow); margin-bottom: 1rem; }
.card-head { display: flex; justify-content: space-between; align-items: baseline; gap: 1rem; flex-wrap: wrap; margin-bottom: .6rem; }
.card-head h3 { margin: 0; }
.narrow { max-width: 720px; margin: 0 auto; }
.grid2 { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1rem; }
.grid2 > .card { margin: 0; }
.grid3 { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1rem; }
.grid3.tight { gap: .75rem; }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: .4rem;
  padding: .6rem 1.05rem; border-radius: 11px; border: 1px solid transparent;
  font: 600 .95rem var(--font); cursor: pointer; text-decoration: none; transition: transform .08s, background .15s;
  background: var(--surface-2); color: var(--ink);
}
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.btn.primary { background: var(--accent); color: var(--accent-ink); }
.btn.primary:hover { filter: brightness(1.08); }
.btn.success { background: var(--ok); color: #fff; }
.btn.ghost { background: transparent; border-color: var(--line); color: var(--ink); }
.btn.ghost:hover { background: var(--surface-2); }
.btn.danger { color: var(--bad); }
.btn.lg { padding: .8rem 1.3rem; font-size: 1rem; }
.btn.sm { padding: .35rem .65rem; font-size: .85rem; border-radius: 9px; }
.linklike { background: none; border: 0; color: var(--accent); font: inherit; text-decoration: underline; cursor: pointer; padding: 0; }
.file-btn { cursor: pointer; }

.chip, .pill {
  display: inline-flex; align-items: center; gap: .25rem; padding: .15rem .55rem; border-radius: 999px;
  font-size: .78rem; font-weight: 500; background: var(--surface-2); color: var(--muted); white-space: nowrap;
}
.chip { background: var(--gold); color: #3b2a00; font-weight: 600; }
.pill.accent { background: var(--accent-soft); color: var(--accent); }

.lv-badge {
  display: inline-grid; place-items: center; min-width: 2.4em; padding: .1em .45em; border-radius: 8px;
  font-weight: 700; font-size: .95em; color: #fff; background: var(--c, var(--accent)); letter-spacing: .02em;
}
.lv-badge.sm { font-size: .75rem; border-radius: 6px; min-width: 2.2em; }
.lv-A1 { --c: var(--A1); } .lv-A2 { --c: var(--A2); } .lv-B1 { --c: var(--B1); } .lv-B2 { --c: var(--B2); } .lv-C1 { --c: var(--C1); }
:root[data-theme="dark"] .lv-badge { color: #0d1520; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .lv-badge { color: #0d1520; } }

.bar { display: block; height: 8px; border-radius: 99px; background: var(--track); overflow: hidden; flex: 1; }
.bar > span { display: block; height: 100%; border-radius: inherit; background: var(--c, var(--accent)); transition: width .4s; }
.progress { height: 6px; background: var(--track); border-radius: 99px; overflow: hidden; margin: .4rem 0 .6rem; }
.progress > span { display: block; height: 100%; background: var(--accent); transition: width .25s; }

/* ---------------- home ---------------- */
.hero { padding: 2.2rem 0 1rem; }
.hero h1 { font-size: clamp(2rem, 6vw, 3.2rem); max-width: 16ch; }
.hero .row { margin-top: 1.4rem; }
.feature .f-icon { font-size: 1.6rem; margin-bottom: .3rem; }
.feature { margin: 0; }

.home-head { display: flex; justify-content: space-between; align-items: center; gap: 1.5rem; }
.home-head h1 { display: flex; align-items: center; gap: .5rem; flex-wrap: wrap; }
.home-head h1 small { font: 500 1rem var(--font); color: var(--muted); }
.goal-ring {
  --size: 128px; width: var(--size); height: var(--size); flex: none; border-radius: 50%;
  background: conic-gradient(var(--ok) calc(var(--p) * 1%), var(--track) 0);
  display: grid; place-items: center;
}
.goal-ring > div {
  width: calc(var(--size) - 22px); height: calc(var(--size) - 22px); border-radius: 50%;
  background: var(--bg); display: flex; flex-direction: column; align-items: center; justify-content: center; line-height: 1.1;
}
.goal-ring strong { font-size: 1.9rem; font-family: var(--display); }
.goal-ring span { font-size: .8rem; color: var(--muted); }
.goal-ring em { font-style: normal; font-size: .72rem; color: var(--muted); text-transform: uppercase; letter-spacing: .06em; margin-top: .15rem; }

.next-card {
  display: block; text-decoration: none; color: var(--ink);
  background: linear-gradient(135deg, #1f3a5f, #2c5282); color: #fff;
  border-radius: 18px; padding: 1.4rem 1.5rem; box-shadow: var(--shadow); margin-bottom: 1.25rem;
}
.next-card h2 { font-family: var(--display); font-size: 1.6rem; margin: .5rem 0 .1rem; }
.next-card .muted { color: rgba(255,255,255,.75); }
.next-card .btn.primary { background: var(--gold); color: #2a1e00; margin-top: .4rem; }
.next-meta { display: flex; gap: .5rem; align-items: center; flex-wrap: wrap; font-size: .88rem; }
.next-card .lv-badge { color: #fff; }

.stat-row { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1rem; }
.stat-row.four { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.tile { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 1rem 1.1rem; display: flex; flex-direction: column; box-shadow: var(--shadow); }
.tile strong { font-family: var(--display); font-size: 1.7rem; line-height: 1.2; }
.tile .t-icon { font-size: 1.15rem; }
.tile .muted { font-size: .85rem; }

.lv-bars { display: grid; gap: .55rem; }
.lv-bar { display: grid; grid-template-columns: 3rem 1fr 3.5rem; align-items: center; gap: .75rem; text-decoration: none; color: inherit; padding: .2rem .3rem; border-radius: 8px; }
.lv-bar:hover { background: var(--surface-2); }
.lv-bar.current { background: var(--accent-soft); }
.lv-bar .small { text-align: right; }

/* ---------------- test ---------------- */
.q-card { padding: 1.6rem; }
.q-text { font-family: var(--display); font-size: 1.5rem; margin-bottom: 1.2rem; }
.blank { color: var(--accent); letter-spacing: .05em; }
.opts { display: grid; grid-template-columns: 1fr 1fr; gap: .6rem; }
.opt {
  text-align: left; padding: .85rem 1rem; border-radius: 12px; border: 1.5px solid var(--line);
  background: var(--surface); color: var(--ink); font: 500 1rem var(--font); cursor: pointer;
}
.opt:hover { border-color: var(--accent); background: var(--accent-soft); }
.opt.picked { border-color: var(--accent); background: var(--accent-soft); }
.opt.idk { grid-column: 1 / -1; text-align: center; color: var(--muted); border-style: dashed; }
.result-badge {
  width: 110px; height: 110px; margin: .5rem auto 1rem; border-radius: 28px; display: grid; place-items: center;
  font: 700 2.6rem var(--display); color: #fff; background: var(--c);
}
.tbl { width: 100%; border-collapse: collapse; }
.tbl th, .tbl td { padding: .5rem; border-bottom: 1px solid var(--line); text-align: left; }

/* ---------------- roadmap ---------------- */
.lv-tabs { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: .5rem; margin-bottom: 1.2rem; }
.lv-tab {
  position: relative; text-decoration: none; color: var(--ink); background: var(--surface);
  border: 1.5px solid var(--line); border-radius: 12px; padding: .6rem .7rem; display: flex; flex-direction: column; line-height: 1.25;
}
.lv-tab strong { font-family: var(--display); font-size: 1.3rem; color: var(--c); }
.lv-tab span { font-size: .78rem; color: var(--muted); }
.lv-tab em { position: absolute; top: .45rem; right: .5rem; font-style: normal; font-size: .68rem; background: var(--gold); color: #3b2a00; padding: 0 .4rem; border-radius: 99px; font-weight: 600; }
.lv-tab.active { border-color: var(--c); background: color-mix(in srgb, var(--c) 10%, var(--surface)); }
.roadmap-head { display: flex; justify-content: space-between; gap: 1.5rem; align-items: flex-end; flex-wrap: wrap; }
.mini-progress { display: grid; grid-template-columns: auto 160px; grid-template-rows: auto auto; column-gap: .75rem; align-items: center; }
.mini-progress strong { grid-row: span 2; font: 700 1.8rem var(--display); }
.chips { display: flex; gap: .4rem; flex-wrap: wrap; margin: .8rem 0 1rem; }
.chip-btn { border: 1px solid var(--line); background: var(--surface); color: var(--ink); padding: .35rem .8rem; border-radius: 99px; font: 500 .88rem var(--font); cursor: pointer; }
.chip-btn.active { background: var(--ink); color: var(--bg); border-color: var(--ink); }

.lesson-list { list-style: none; padding: 0; margin: 0; display: grid; gap: .55rem; }
.lesson-row {
  display: grid; grid-template-columns: 2.4rem 1fr auto; gap: .9rem; align-items: center;
  background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: .8rem 1rem;
  text-decoration: none; color: var(--ink); transition: border-color .15s, transform .1s;
}
.lesson-row:hover { border-color: var(--accent); transform: translateX(2px); }
.lesson-row .num {
  width: 2.2rem; height: 2.2rem; border-radius: 50%; display: grid; place-items: center;
  background: var(--surface-2); font-weight: 700; color: var(--muted);
}
.lesson-row.done .num { background: var(--ok); color: #fff; }
.l-main { display: flex; flex-direction: column; min-width: 0; }
.l-main strong { overflow: hidden; text-overflow: ellipsis; }
.l-meta { display: flex; gap: .3rem; flex-wrap: wrap; justify-content: flex-end; }
.res-list { list-style: none; padding: 0; margin: 0; display: grid; gap: .55rem; }
.res-list li { display: flex; flex-direction: column; }

/* ---------------- lesson ---------------- */
.crumbs { font-size: .88rem; color: var(--muted); margin-bottom: .8rem !important; }
.crumbs a { color: var(--muted); }
.lesson-head { display: flex; justify-content: space-between; align-items: flex-start; gap: 1rem; margin-bottom: 1rem; }
.lesson-head h1 { margin-top: .5rem; }
.lesson-grid { display: grid; grid-template-columns: minmax(0, 1.7fr) minmax(0, 1fr); gap: 1rem; margin-bottom: 1rem; }
.lesson-side .card:last-child { margin-bottom: 0; }
.player-wrap { margin-bottom: 1rem; }
.video { position: relative; aspect-ratio: 16 / 9; background: #000; border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); }
.video iframe, .video > div { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.video .ext-card { position: absolute; inset: 0; border-radius: 0; }
.player-bar { display: flex; align-items: center; gap: .6rem; flex-wrap: wrap; padding: .6rem .2rem 0; }
.watch-pct { margin-left: auto; }
.seg { display: inline-flex; border: 1px solid var(--line); border-radius: 9px; overflow: hidden; }
.seg-btn { border: 0; background: transparent; color: var(--ink); padding: .32rem .6rem; font: 600 .82rem var(--font); cursor: pointer; }
.seg-btn.active { background: var(--accent); color: var(--accent-ink); }

.ext-card {
  display: flex; gap: 1.1rem; align-items: flex-start; padding: 1.4rem;
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow);
}
.ext-card h2 { font-family: var(--display); }
.ext-logo {
  flex: none; width: 64px; height: 64px; border-radius: 16px; display: grid; place-items: center;
  background: #23085a; color: #fff; font-weight: 800; font-size: 1.2rem; letter-spacing: .02em;
}
.ext-logo.yt { background: #c4302b; }
.banner {
  margin-top: .8rem; padding: .8rem 1rem; border-radius: 12px; background: var(--gold); color: #2a1e00;
  display: flex; justify-content: space-between; align-items: center; gap: .8rem; flex-wrap: wrap;
}
.banner .btn.ghost { border-color: rgba(0,0,0,.25); color: #2a1e00; }
.banner .btn.primary { background: #1f3a5f; color: #fff; }
.time-log { padding: .8rem 1rem; font-size: .92rem; }
.steps { margin: 0; padding-left: 1.2rem; }
.steps li { margin-bottom: .3rem; }

.vocab { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: .5rem 1.4rem; }
.vocab li { display: flex; gap: .6rem; align-items: flex-start; padding: .55rem 0; border-bottom: 1px dashed var(--line); }
.vocab .vi { color: var(--muted); }
.vocab .ex { font-size: .9rem; color: var(--muted); margin-top: .15rem; }
.hide-vi .vocab .vi { filter: blur(5px); transition: filter .2s; cursor: pointer; }
.hide-vi .vocab li:hover .vi { filter: none; }
.say { border: 1px solid var(--line); background: var(--surface-2); border-radius: 8px; cursor: pointer; padding: .2rem .4rem; font-size: .9rem; line-height: 1; color: var(--ink); }
.say.sm { font-size: .65rem; padding: .15rem .3rem; vertical-align: middle; }

.quiz { display: grid; gap: .8rem; }
.qz { border: 1px solid var(--line); border-radius: 12px; padding: .8rem 1rem; margin: 0; }
.qz legend { padding: 0 .3rem; font-weight: 600; }
.qn { display: inline-grid; place-items: center; width: 1.5rem; height: 1.5rem; border-radius: 50%; background: var(--surface-2); font-size: .8rem; margin-right: .2rem; }
.qz-opts { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: .4rem; margin-top: .3rem; }
.qz-opts label { display: flex; gap: .5rem; align-items: center; padding: .45rem .6rem; border-radius: 9px; border: 1px solid transparent; cursor: pointer; }
.qz-opts label:hover { background: var(--surface-2); }
.qz-opts label.right { border-color: var(--ok); background: var(--ok-soft); }
.qz-opts label.wrong { border-color: var(--bad); background: var(--bad-soft); }
.qz.is-right { border-color: var(--ok); }
.qz.is-wrong { border-color: var(--bad); }
.fb { margin: .3rem 0 0; font-size: .88rem; min-height: 0; }
.qz.is-right .fb { color: var(--ok); }
.qz.is-wrong .fb { color: var(--bad); }
.quiz-result { font-weight: 500; margin: 0; padding: .6rem .8rem; border-radius: 10px; }
.quiz-result:empty { display: none; }
.quiz-result.good { background: var(--ok-soft); }
.quiz-result.bad { background: var(--bad-soft); }

input, select, textarea {
  width: 100%; font: 1rem var(--font); color: var(--ink); background: var(--bg);
  border: 1.5px solid var(--line); border-radius: 10px; padding: .6rem .75rem; margin-top: .3rem;
}
input:focus, select:focus, textarea:focus { outline: none; border-color: var(--accent); }
input[type="radio"] { width: auto; margin: 0; accent-color: var(--accent); }
textarea { resize: vertical; line-height: 1.5; }
.form { display: grid; gap: .9rem; }
.form label { font-weight: 500; font-size: .92rem; }
.fill { max-width: 320px; }

.pager { display: flex; justify-content: space-between; gap: 1rem; }
.pager .btn { max-width: 48%; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; display: block; }

/* ---------------- dashboard ---------------- */
.chart { width: 100%; height: auto; display: block; }
.chart .grid { stroke: var(--line); stroke-width: 1; }
.chart .ax { fill: var(--muted); font: 12px var(--font); }
.chart .ax.sm { font-size: 10px; }
.chart .ax.today { fill: var(--ink); font-weight: 700; }
.chart .col { fill: color-mix(in srgb, var(--accent) 45%, var(--track)); }
.chart .col.hit { fill: var(--ok); }
.chart .val { fill: var(--ink); font: 600 11px var(--font); }
.chart .goal { stroke: var(--gold); stroke-width: 2; stroke-dasharray: 6 5; }
.legend { display: inline-flex; align-items: center; gap: .3rem; }
.lg-goal { display: inline-block; width: 18px; border-top: 2px dashed var(--gold); }

.rings { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: .5rem; text-align: center; }
.ring-item { display: flex; flex-direction: column; align-items: center; gap: .2rem; }
.ring {
  --size: 88px; width: var(--size); height: var(--size); border-radius: 50%; margin-bottom: .3rem;
  background: conic-gradient(var(--c) calc(var(--p) * 1%), var(--track) 0); display: grid; place-items: center;
}
.ring span { width: calc(var(--size) - 18px); height: calc(var(--size) - 18px); border-radius: 50%; background: var(--surface); display: grid; place-items: center; font: 700 1.1rem var(--display); }
.sk-listening { --c: var(--B1); } .sk-vocab { --c: var(--A1); } .sk-grammar { --c: var(--B2); }

.heat-wrap { display: flex; gap: .4rem; overflow-x: auto; padding-bottom: .3rem; }
.heat-days { display: grid; grid-template-rows: repeat(7, 14px); gap: 3px; font-size: .65rem; line-height: 14px; }
.heat { display: grid; grid-auto-flow: column; grid-template-rows: repeat(7, 14px); grid-auto-columns: minmax(14px, 1fr); gap: 3px; flex: 1; min-width: 330px; }
.heat .h { width: 100%; }
.h { display: inline-block; width: 14px; height: 14px; border-radius: 3px; background: var(--track); }
.h1 { background: color-mix(in srgb, var(--ok) 30%, var(--track)); }
.h2 { background: color-mix(in srgb, var(--ok) 55%, var(--track)); }
.h3 { background: color-mix(in srgb, var(--ok) 80%, var(--track)); }
.h4 { background: var(--ok); }
.legend .h { width: 11px; height: 11px; }

.recent, .custom-list { list-style: none; padding: 0; margin: 0 0 .8rem; }
.recent li, .custom-list li { display: flex; justify-content: space-between; align-items: center; gap: 1rem; padding: .55rem 0; border-bottom: 1px solid var(--line); }
.recent a, .custom-list a { text-decoration: none; color: var(--ink); display: flex; gap: .5rem; align-items: center; }

/* ---------------- toasts ---------------- */
#toasts { position: fixed; left: 50%; bottom: 24px; transform: translateX(-50%); display: grid; gap: .5rem; z-index: 50; width: min(92vw, 420px); }
.toast { background: var(--ink); color: var(--bg); padding: .7rem 1rem; border-radius: 12px; box-shadow: var(--shadow); opacity: 0; transform: translateY(10px); transition: .25s; font-size: .93rem; text-align: center; }
.toast.show { opacity: 1; transform: none; }
.toast.ok { background: var(--ok); color: #fff; }
.toast.err { background: var(--bad); color: #fff; }

/* ---------------- responsive ---------------- */
@media (max-width: 860px) {
  .lesson-grid { grid-template-columns: 1fr; }
  .stat-row.four { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid2 { grid-template-columns: 1fr; }
}
@media (max-width: 720px) {
  body { padding-bottom: 70px; }
  .topbar { padding: .55rem 16px; backdrop-filter: none; background: var(--bg); }
  .nav {
    position: fixed; left: 0; right: 0; bottom: 0; margin: 0; z-index: 30;
    background: var(--surface); border-top: 1px solid var(--line);
    justify-content: space-around; padding: .3rem .2rem calc(.3rem + env(safe-area-inset-bottom));
  }
  .nav a { flex-direction: column; gap: 0; font-size: .68rem; padding: .3rem .4rem; }
  .nav a span { font-size: 1.15rem; }
  .icon-btn { margin-left: auto; }
  #toasts { bottom: 86px; }
  .grid3 { grid-template-columns: 1fr; }
  .stat-row { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: .5rem; }
  .tile { padding: .75rem; }
  .tile strong { font-size: 1.3rem; }
  .home-head { flex-direction: column; align-items: flex-start; }
  .goal-ring { --size: 112px; align-self: center; }
  .opts, .qz-opts, .vocab { grid-template-columns: 1fr; }
  .lv-tabs { grid-template-columns: repeat(5, minmax(56px, 1fr)); overflow-x: auto; }
  .lv-tab span { display: none; }
  .lv-tab { align-items: center; padding: .5rem .3rem; }
  .lv-tab em { top: -8px; right: 50%; transform: translateX(50%); }
  .lesson-row { grid-template-columns: 2.2rem 1fr; }
  .l-meta { grid-column: 2; justify-content: flex-start; }
  .lesson-head { flex-direction: column; }
  .lesson-head .btn { width: 100%; }
  .ext-card { flex-direction: column; }
  .mini-progress { grid-template-columns: auto 1fr; width: 100%; }
  .rings { gap: .2rem; }
  .ring { --size: 72px; }
  .pager .btn { font-size: .82rem; }
  .chart .ax { font-size: 22px; } .chart .ax.sm { font-size: 17px; } .chart .val { font-size: 20px; }
  .heat { min-width: 0; grid-template-rows: repeat(7, 12px); gap: 2px; }
  .heat-days { grid-template-rows: repeat(7, 12px); gap: 2px; line-height: 12px; }
}

/* ==========================================================================
   Game hoá (Phần 1)
   ========================================================================== */
:root { --xp: #e0a91b; --daily: #f6c453; }
.nav { margin-left: auto; }
.nav-ic { position: relative; }
.dot {
  position: absolute; top: -6px; right: -10px; min-width: 16px; height: 16px; padding: 0 4px;
  border-radius: 99px; background: var(--bad); color: #fff; font: 700 10px/16px var(--font); font-style: normal; text-align: center;
}
.dot[hidden] { display: none; }
.xp-chip {
  display: flex; align-items: center; gap: .45rem; text-decoration: none; color: var(--ink);
  border: 1px solid var(--line); background: var(--surface); border-radius: 99px; padding: .3rem .7rem; font-size: .8rem; white-space: nowrap;
}
.xc-lv { font-weight: 700; color: var(--xp); }
.xc-bar { width: 54px; height: 6px; border-radius: 99px; background: var(--track); overflow: hidden; display: block; }
.xc-bar span { display: block; height: 100%; background: var(--xp); }
.xc-xp { color: var(--muted); }

.xp-line { display: flex; align-items: center; gap: .6rem; flex-wrap: wrap; margin-top: .3rem; }
.xp-lv { background: var(--xp); color: #2a1e00; font-weight: 700; font-size: .8rem; padding: .1rem .55rem; border-radius: 99px; }
.xp-lv.big { font: 700 1.3rem var(--display); padding: .5rem .9rem; border-radius: 14px; }
.bar.xp { max-width: 220px; min-width: 120px; --c: var(--xp); }
.xp-card .xp-big { display: flex; gap: 1rem; align-items: center; }
.xp-meta { display: grid; gap: .25rem; flex: 1; }
.xp-meta .bar.xp { max-width: none; height: 10px; }
.xp-meta strong { font: 700 1.4rem var(--display); }
.xp-rules { margin-top: .7rem; padding-top: .6rem; border-top: 1px dashed var(--line); }

.banner.risk { background: color-mix(in srgb, var(--bad) 14%, var(--surface)); color: var(--ink); margin-bottom: 1rem; }
.banner.risk .btn.primary { background: var(--bad); color: #fff; }
.banner.daily-banner { margin: 0 0 1rem; }

.next-card.daily { background: linear-gradient(135deg, #3a2a00, #8a5a00 55%, #c8871a); }
.next-card.daily .chip { background: #fff4cf; }
.next-card.is-done { filter: saturate(.55); }
.chip.ghost { background: var(--surface-2); color: var(--muted); }
.next-mini { display: flex; flex-direction: column; gap: .2rem; text-decoration: none; color: var(--ink); }
.next-mini:hover { border-color: var(--accent); }

.quick-row { display: grid; grid-template-columns: 1fr 1fr 1.4fr; gap: 1rem; margin-bottom: 1.25rem; }
.quick { display: flex; gap: .8rem; align-items: center; text-decoration: none; color: var(--ink); margin: 0; position: relative; }
a.quick:hover { border-color: var(--accent); }
.quick > span:nth-child(2) { display: flex; flex-direction: column; min-width: 0; }
.q-icon { font-size: 1.7rem; }
.q-badge { position: absolute; top: .6rem; right: .7rem; background: var(--bad); color: #fff; border-radius: 99px; font: 700 .75rem var(--font); padding: .1rem .5rem; }
.wotd .eyebrow { margin: 0; }
.wotd em { display: block; margin-top: .1rem; }
.wotd .say { margin-left: auto; }

.pill.new { background: color-mix(in srgb, var(--ok) 18%, var(--surface)); color: var(--ok); }
.pill.ai { background: color-mix(in srgb, var(--B2) 16%, var(--surface)); color: var(--B2); }
.pill.daily { background: var(--daily); color: #3b2a00; }
.lesson-row.is-daily { border-color: var(--daily); box-shadow: 0 0 0 2px color-mix(in srgb, var(--daily) 40%, transparent); }
.auto-head { margin-top: 1.4rem; }
.desc { white-space: pre-line; max-height: 14em; overflow: auto; }

/* huy hiệu */
.badges { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: .6rem; }
.badges li { border: 1px solid var(--line); border-radius: 12px; padding: .7rem; display: flex; flex-direction: column; align-items: center; text-align: center; gap: .15rem; opacity: .55; filter: grayscale(1); }
.badges li.got { opacity: 1; filter: none; background: color-mix(in srgb, var(--daily) 10%, var(--surface)); border-color: color-mix(in srgb, var(--daily) 50%, var(--line)); }
.b-icon { font-size: 1.8rem; }

/* pháo giấy, popup, XP nổi */
.confetti { position: fixed; inset: 0; width: 100vw; height: 100vh; pointer-events: none; z-index: 90; }
.celebrate {
  position: fixed; left: 50%; top: 40%; transform: translate(-50%, -40%) scale(.85); opacity: 0; transition: .25s;
  background: var(--surface); border: 2px solid var(--daily); border-radius: 22px; padding: 1.4rem 2rem; text-align: center;
  box-shadow: 0 20px 60px rgba(0,0,0,.25); z-index: 95; width: min(90vw, 360px); cursor: pointer;
}
.celebrate.show { opacity: 1; transform: translate(-50%, -40%) scale(1); }
.celebrate h2 { font-family: var(--display); font-size: 1.6rem; }
.cel-icon { font-size: 3.2rem; line-height: 1.2; }
.xp-float { position: fixed; right: 24px; top: 70px; z-index: 96; font: 800 1.2rem var(--display); color: var(--xp); animation: xpUp 1.3s ease-out forwards; pointer-events: none; text-shadow: 0 1px 0 var(--surface); }
@keyframes xpUp { from { opacity: 0; transform: translateY(10px); } 20% { opacity: 1; } to { opacity: 0; transform: translateY(-40px); } }
.toast.xp { background: var(--xp); color: #2a1e00; }

/* flashcard */
.review-head { display: flex; justify-content: space-between; align-items: flex-end; gap: 1rem; flex-wrap: wrap; }
.boxes { display: flex; gap: .4rem; align-items: flex-end; height: 76px; }
.box { width: 34px; height: 100%; display: flex; flex-direction: column; justify-content: flex-end; align-items: center; position: relative; }
.box > span { width: 100%; border-radius: 6px 6px 2px 2px; background: color-mix(in srgb, var(--ok) calc(20% * var(--i, 1)), var(--track)); }
.box.b1 > span { background: color-mix(in srgb, var(--bad) 55%, var(--track)); }
.box.b2 > span { background: color-mix(in srgb, var(--xp) 55%, var(--track)); }
.box.b3 > span { background: color-mix(in srgb, var(--ok) 40%, var(--track)); }
.box.b4 > span { background: color-mix(in srgb, var(--ok) 70%, var(--track)); }
.box.b5 > span { background: var(--ok); }
.box em { position: absolute; top: 0; font: 600 .7rem var(--font); font-style: normal; color: var(--muted); }
.box small { font-size: .65rem; color: var(--muted); }
.toggle { display: inline-flex; gap: .3rem; align-items: center; cursor: pointer; }
.flash { display: block; width: 100%; height: 260px; perspective: 1200px; border: 0; background: none; padding: 0; cursor: pointer; margin: .5rem 0 1rem; color: var(--ink); font: inherit; }
.f-inner { position: relative; display: block; width: 100%; height: 100%; transition: transform .45s; transform-style: preserve-3d; }
.flash.flipped .f-inner { transform: rotateY(180deg); }
.f-face {
  position: absolute; inset: 0; backface-visibility: hidden; border-radius: 20px; border: 1px solid var(--line);
  background: var(--surface); box-shadow: var(--shadow); display: flex; flex-direction: column; align-items: center; justify-content: center; gap: .5rem; padding: 1.2rem; text-align: center;
}
.f-front strong { font: 700 2.3rem var(--display); }
.f-back { transform: rotateY(180deg); background: color-mix(in srgb, var(--accent) 8%, var(--surface)); }
.f-back strong { font: 700 1.6rem var(--display); }
.f-vi { font-size: 1.35rem; font-weight: 600; color: var(--accent); }
.f-back em { color: var(--muted); max-width: 40ch; }
.box-tag { position: absolute; top: .8rem; left: .9rem; font-size: .72rem; color: var(--muted); background: var(--surface-2); padding: .05rem .5rem; border-radius: 99px; }
.grades { display: grid; grid-template-columns: repeat(3, 1fr); gap: .6rem; margin-bottom: 1rem; }
.grades.hidden { visibility: hidden; }
.grade { padding: .8rem; font-size: 1rem; }
.grade b { font-size: .7rem; opacity: .6; border: 1px solid currentColor; border-radius: 4px; padding: 0 .3rem; }
.g0 { background: var(--bad-soft); color: var(--bad); }
.g1 { background: var(--ok-soft); color: var(--ok); }
.g2 { background: var(--accent-soft); color: var(--accent); }

/* mini game */
.game-card { text-decoration: none; color: var(--ink); margin: 0; display: flex; flex-direction: column; gap: .2rem; }
.game-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.g-icon { font-size: 2rem; }
.review-cta { display: flex; justify-content: space-between; align-items: center; gap: 1rem; margin-top: 1.2rem; }
.timer { font: 700 1.3rem var(--display); color: var(--accent); }
.match-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: .6rem; margin: 1rem 0; }
.tile-btn {
  min-height: 74px; border-radius: 14px; border: 1.5px solid var(--line); background: var(--surface); color: var(--ink);
  font: 600 .95rem var(--font); cursor: pointer; padding: .5rem; transition: transform .1s, opacity .3s;
}
.tile-btn.w { border-bottom: 4px solid var(--B1); }
.tile-btn.vi { border-bottom: 4px solid var(--A1); font-weight: 500; }
.tile-btn.sel { background: var(--accent-soft); border-color: var(--accent); transform: scale(1.03); }
.tile-btn.ok { opacity: 0; pointer-events: none; transform: scale(.85); }
.tile-btn.bad { animation: shake .4s; border-color: var(--bad); background: var(--bad-soft); }
@keyframes shake { 25% { transform: translateX(-5px); } 75% { transform: translateX(5px); } }
.speed-top { display: flex; justify-content: space-between; margin: .6rem 0; }
.opt.picked-ok { border-color: var(--ok); background: var(--ok-soft); }
.opt.picked-bad { border-color: var(--bad); background: var(--bad-soft); }
.dict-res { margin-top: .8rem; line-height: 1.9; }
.w-ok { color: var(--ok); }
.w-bad { color: var(--bad); text-decoration: underline wavy; text-underline-offset: 4px; }
.game .card textarea { margin: .7rem 0; }

@media (max-width: 960px) {
  .xc-bar, .xc-xp { display: none; }
}
@media (max-width: 860px) {
  .quick-row { grid-template-columns: 1fr 1fr; }
  .wotd { grid-column: 1 / -1; }
}
@media (max-width: 720px) {
  .xp-chip { margin-left: auto; }
  .xc-bar, .xc-xp { display: block; }
  .icon-btn { margin-left: .4rem; }
  .match-grid { grid-template-columns: repeat(3, 1fr); }
  .flash { height: 230px; }
  .f-front strong { font-size: 1.9rem; }
  .boxes { height: 60px; }
  .box { width: 28px; }
  .review-cta { flex-direction: column; align-items: flex-start; }
  .xp-float { top: 60px; right: 16px; }
}
@media (max-width: 420px) {
  .quick-row { grid-template-columns: 1fr; }
  .xc-xp { display: none; }
}

.cel-hint { margin: .4rem 0 0; font-size: .7rem; }
.toggle { white-space: nowrap; font-size: .82rem; }
.next-mini .chip { align-self: flex-start; }
@media (max-width: 720px) {
  .badges { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: .4rem; }
  .badges li { padding: .5rem .3rem; }
  .badges li strong { font-size: .78rem; line-height: 1.2; }
  .badges li .small { font-size: .66rem; line-height: 1.25; }
  .b-icon { font-size: 1.4rem; }
}