/* =========================================================
   SpeakFlow — design system v2
   Inspired by shadcn/ui dark: neutral surfaces, hairline
   borders, one accent, generous spacing, real type scale.
   ========================================================= */
:root {
  --bg: #09090b;
  --surface: #0f0f12;
  --panel: #131317;
  --elev: #1a1a20;
  --elev2: #202028;
  --line: rgba(255,255,255,.07);
  --line-2: rgba(255,255,255,.12);
  --text: #f4f4f5;
  --muted: #a1a1aa;
  --dim: #71717a;
  --accent: #6366f1;
  --accent-hi: #818cf8;
  --accent-soft: rgba(99,102,241,.14);
  --accent-ring: rgba(99,102,241,.25);
  --green: #34d399;  --green-soft: rgba(52,211,153,.12);
  --amber: #fbbf24;  --amber-soft: rgba(251,191,36,.12);
  --red: #f87171;    --red-soft: rgba(248,113,113,.12);
  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 1px 0 rgba(255,255,255,.03) inset, 0 12px 32px rgba(0,0,0,.45);
  --font-body: "Inter", "Segoe UI", system-ui, sans-serif;
  --font-display: "Sora", "Inter", system-ui, sans-serif;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { height: 100%; }
body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text);
  font-size: 15px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}
::selection { background: var(--accent-ring); }
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-thumb { background: var(--elev2); border-radius: 99px; border: 3px solid var(--bg); }
::-webkit-scrollbar-track { background: transparent; }
button { font: inherit; color: inherit; cursor: pointer; background: none; border: none; }
input, textarea, select { font: inherit; }
a { color: var(--accent-hi); }
.hidden { display: none !important; }
.muted { color: var(--muted); font-size: .9rem; line-height: 1.6; }
h1, h2, h3 { font-family: var(--font-display); letter-spacing: -.01em; }

.app { display: flex; min-height: 100vh; }

/* ---------- Sidebar ---------- */
.sidebar {
  width: 250px; flex-shrink: 0; padding: 20px 14px;
  display: flex; flex-direction: column; gap: 28px;
  border-right: 1px solid var(--line);
  background: var(--surface);
  position: sticky; top: 0; height: 100vh;
}
.brand { display: flex; align-items: center; gap: 11px; padding: 2px 8px; }
.brand-logo {
  width: 36px; height: 36px; border-radius: 11px;
  background: linear-gradient(160deg, var(--accent), #4f46e5);
  box-shadow: 0 4px 14px rgba(99,102,241,.35);
  display: grid; place-items: center; font-family: var(--font-display);
  font-weight: 800; color: #fff; font-size: .82rem;
}
.brand-name { font-family: var(--font-display); font-weight: 700; font-size: 1rem; letter-spacing: -.02em; }
.brand-sub { font-size: .68rem; color: var(--dim); font-weight: 500; letter-spacing: .02em; }

.nav { display: flex; flex-direction: column; gap: 3px; }
.nav-item {
  position: relative; display: flex; align-items: center; gap: 12px;
  padding: 10px 12px; border-radius: var(--radius-sm);
  color: var(--dim); font-weight: 500; font-size: .92rem; transition: .16s ease;
}
.nav-item:hover { background: var(--panel); color: var(--text); }
.nav-item.active { background: var(--elev); color: var(--text); font-weight: 600; }
.nav-item.active::before {
  content: ""; position: absolute; left: -14px; top: 50%; translate: 0 -50%;
  width: 3px; height: 18px; border-radius: 0 3px 3px 0; background: var(--accent);
}
.nav-ico {
  width: 26px; height: 26px; border-radius: 8px; display: grid; place-items: center;
  background: var(--panel); border: 1px solid var(--line); font-size: .75rem; color: var(--muted);
}
.nav-item.active .nav-ico { background: var(--accent-soft); border-color: transparent; color: var(--accent-hi); }

.sidebar-footer { margin-top: auto; display: flex; align-items: center; gap: 8px; }
.user-chip {
  flex: 1; background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius-sm);
  padding: 9px 12px; font-size: .83rem; color: var(--muted);
  overflow: hidden; white-space: nowrap; text-overflow: ellipsis;
}
.user-chip b { color: var(--text); font-weight: 600; }
.ghost-btn { color: var(--dim); font-size: .78rem; padding: 7px 10px; border-radius: 8px; border: 1px solid transparent; }
.ghost-btn:hover { background: var(--panel); border-color: var(--line); color: var(--text); }

/* ---------- Main ---------- */
.main { flex: 1; min-width: 0; padding: 34px 42px 70px; max-width: 1120px; }
.view-head { display: flex; justify-content: space-between; align-items: flex-start; gap: 20px; margin-bottom: 26px; }
.view-head h1 { font-size: 1.55rem; font-weight: 700; margin-bottom: 4px; }
.level-badge {
  padding: 7px 16px; border-radius: 999px; font-family: var(--font-display);
  background: var(--accent-soft); border: 1px solid rgba(99,102,241,.35);
  color: var(--accent-hi); font-weight: 700; font-size: .85rem; white-space: nowrap;
}

/* ---------- Cards ---------- */
.card {
  background: linear-gradient(180deg, var(--elev) 0%, var(--panel) 100%);
  border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px; box-shadow: var(--shadow);
}
.card h3 { margin-bottom: 6px; font-size: .95rem; font-weight: 600; }
.eyebrow { font-size: .68rem; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; color: var(--dim); margin-bottom: 10px; }

.stat-row { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 14px; margin-bottom: 24px; }
.stat { padding: 18px; }
.stat .v { font-family: var(--font-display); font-size: 1.55rem; font-weight: 700; letter-spacing: -.02em; }
.stat .l { color: var(--dim); font-size: .78rem; margin-top: 3px; font-weight: 500; }

.home-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 14px; margin-bottom: 24px; }
.quick-card { display: flex; align-items: center; gap: 16px; cursor: pointer; transition: .18s ease; }
.quick-card:hover { transform: translateY(-2px); border-color: rgba(99,102,241,.4); box-shadow: 0 16px 40px rgba(0,0,0,.5); }
.quick-ico {
  font-size: 1.35rem; width: 48px; height: 48px; border-radius: 13px; display: grid; place-items: center;
  background: var(--accent-soft); border: 1px solid rgba(99,102,241,.25); flex-shrink: 0;
}
.quick-ico.pen { background: var(--green-soft); border-color: rgba(52,211,153,.25); }
.quick-ico.ear { background: var(--amber-soft); border-color: rgba(251,191,36,.25); }
.quick-card h3 { margin-bottom: 2px; }
.quick-card .go { margin-left: auto; color: var(--dim); transition: .18s; }
.quick-card:hover .go { color: var(--accent-hi); transform: translateX(3px); }

.rec-list { display: flex; flex-direction: column; gap: 8px; margin-top: 12px; }
.rec-item {
  display: flex; align-items: center; gap: 12px; padding: 13px 15px;
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-sm);
  cursor: pointer; transition: .16s ease;
}
.rec-item:hover { border-color: rgba(99,102,241,.45); background: var(--panel); }
.rec-item b { font-weight: 600; font-size: .92rem; }
.rec-item .muted { font-size: .78rem; }
.rec-tag {
  font-family: var(--font-display); font-size: .66rem; font-weight: 700; letter-spacing: .04em;
  padding: 3px 9px; border-radius: 999px; flex-shrink: 0;
}
.tag-B1 { background: var(--green-soft); color: var(--green); }
.tag-B2 { background: var(--accent-soft); color: var(--accent-hi); }
.tag-C1 { background: var(--amber-soft); color: var(--amber); }
.tag-C2 { background: var(--red-soft); color: var(--red); }

/* ---------- Buttons ---------- */
.btn {
  padding: 10px 18px; border-radius: var(--radius-sm); font-weight: 600; font-size: .9rem;
  transition: .16s ease; border: 1px solid transparent; display: inline-flex; align-items: center; gap: 8px;
}
.btn.primary {
  background: var(--accent); color: #fff;
  box-shadow: 0 4px 14px rgba(99,102,241,.3);
}
.btn.primary:hover { background: #4f46e5; }
.btn.primary:disabled { opacity: .4; cursor: not-allowed; box-shadow: none; }
.btn.ghost { border-color: var(--line-2); color: var(--muted); background: transparent; }
.btn.ghost:hover { color: var(--text); border-color: var(--dim); background: var(--panel); }
.btn.big { padding: 13px 26px; font-size: .95rem; }

/* ---------- Practice ---------- */
.crumb { color: var(--dim); font-size: .84rem; margin-bottom: 18px; }
.crumb b { color: var(--text); font-weight: 600; }
.crumb button { color: var(--dim); text-decoration: none; border-bottom: 1px dashed var(--line-2); padding-bottom: 1px; }
.crumb button:hover { color: var(--accent-hi); border-color: var(--accent-hi); }
.practice-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 14px; }
.task-card { cursor: pointer; transition: .18s ease; display: flex; flex-direction: column; gap: 8px; }
.task-card:hover { transform: translateY(-2px); border-color: rgba(99,102,241,.4); }
.task-card b { font-weight: 600; font-size: .95rem; line-height: 1.5; }
.task-meta { display: flex; gap: 8px; align-items: center; }
.task-type { font-size: .7rem; color: var(--dim); text-transform: uppercase; letter-spacing: .08em; font-weight: 600; }
.cat-chip {
  font-size: .7rem; font-weight: 600; color: var(--accent-hi);
  background: var(--accent-soft); border: 1px solid rgba(99,102,241,.22);
  padding: 2px 10px; border-radius: 999px; white-space: nowrap;
}
.filter-row { display: flex; gap: 7px; flex-wrap: wrap; margin-bottom: 18px; }
.fchip {
  font-size: .8rem; font-weight: 500; color: var(--muted);
  background: var(--surface); border: 1px solid var(--line);
  padding: 6px 14px; border-radius: 999px; transition: .15s; font-variant-numeric: tabular-nums;
}
.fchip:hover { border-color: var(--dim); color: var(--text); }
.fchip.sel { background: var(--accent-soft); border-color: var(--accent); color: var(--accent-hi); font-weight: 600; }

/* build-sentence hints */
.hint-chip {
  display: inline-block; font-size: .78rem; color: var(--muted);
  border: 1px dashed var(--line-2); padding: 3px 11px; border-radius: 999px; margin: 2px 4px 2px 0;
}
/* per-sentence breakdown */
.sent-row { display: flex; gap: 12px; padding: 11px 0; border-bottom: 1px solid var(--line); }
.sent-row:last-child { border-bottom: none; }
.sent-n { width: 24px; height: 24px; border-radius: 8px; display: grid; place-items: center; font-size: .72rem; font-weight: 700; flex-shrink: 0; background: var(--elev2); }
.sent-row.ok .sent-n { background: var(--green-soft); color: var(--green); }
.sent-row.bad .sent-n { background: var(--red-soft); color: var(--red); }
.sent-t { font-size: .9rem; font-style: italic; line-height: 1.5; }

/* ---------- Level-up exam ---------- */
.exam-banner {
  display: flex; align-items: center; gap: 16px; margin-bottom: 22px;
  border-color: rgba(99,102,241,.45);
  background: linear-gradient(180deg, rgba(99,102,241,.13), var(--panel) 90%);
}
.exam-banner .go-ico {
  font-size: 1.5rem; width: 52px; height: 52px; border-radius: 15px; display: grid; place-items: center;
  background: var(--accent-soft); border: 1px solid rgba(99,102,241,.3); flex-shrink: 0;
}
.exam-steps { display: flex; gap: 8px; margin: 6px 0 22px; flex-wrap: wrap; }
.estep { font-size: .72rem; font-weight: 500; padding: 5px 13px; border-radius: 999px; border: 1px solid var(--line); color: var(--dim); white-space: nowrap; }
.estep.cur { border-color: var(--accent); color: var(--accent-hi); background: var(--accent-soft); font-weight: 700; }
.estep.done { color: var(--green); border-color: rgba(52,211,153,.35); background: var(--green-soft); }
.exam-q { font-family: var(--font-display); font-size: 1.05rem; font-weight: 600; line-height: 1.6; margin: 4px 0 14px; }
.exam-qwhy { margin-top: 14px; font-size: .85rem; color: var(--muted); background: var(--surface); border: 1px solid var(--line); border-radius: 10px; padding: 10px 14px; }
.exam-qwhy:empty { display: none; }
.exam-prog { height: 6px; background: var(--surface); border: 1px solid var(--line); border-radius: 999px; overflow: hidden; margin-top: 18px; }
.exam-prog-fill { height: 100%; border-radius: 999px; background: linear-gradient(90deg, var(--accent), var(--accent-hi)); transition: width .5s ease; }
.quiz-opt.right { border-color: rgba(52,211,153,.55); color: var(--green); background: var(--green-soft); }
.quiz-opt.wrong { border-color: rgba(248,113,113,.55); color: var(--red); background: var(--red-soft); }
.quiz-opt:disabled { cursor: default; }

.prompt-box {
  background: var(--surface); border: 1px solid var(--line); border-radius: 12px;
  padding: 18px; font-size: 1rem; line-height: 1.65; margin-bottom: 16px;
}
.read-text { font-family: var(--font-display); font-size: 1.25rem; line-height: 1.85; text-align: center; padding: 32px 20px; font-weight: 600; letter-spacing: -.005em; }
.checklist { margin: 12px 0 0; padding-left: 0; list-style: none; }
.checklist li { color: var(--muted); font-size: .86rem; padding: 4px 0 4px 24px; position: relative; }
.checklist li::before { content: "→"; position: absolute; left: 0; color: var(--accent); font-weight: 700; }

/* recorder */
.recorder { display: flex; flex-direction: column; align-items: center; gap: 16px; padding: 24px 8px 8px; }
.rec-btn {
  width: 78px; height: 78px; border-radius: 50%;
  background: var(--accent); color: #fff; font-size: 1.75rem;
  display: grid; place-items: center; transition: .2s;
  box-shadow: 0 8px 28px rgba(99,102,241,.4);
}
.rec-btn:hover { background: #4f46e5; transform: scale(1.04); }
.rec-btn.recording { background: var(--red); animation: pulse 1.5s infinite; box-shadow: 0 0 0 0 rgba(248,113,113,.35); }
@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(248,113,113,.45); }
  70% { box-shadow: 0 0 0 24px rgba(248,113,113,0); }
  100% { box-shadow: 0 0 0 0 rgba(248,113,113,0); }
}
.rec-timer { font-family: var(--font-display); font-size: 1.35rem; font-weight: 700; font-variant-numeric: tabular-nums; letter-spacing: .02em; }
.transcript {
  width: 100%; min-height: 90px; background: var(--surface); color: var(--text);
  border: 1px solid var(--line); border-radius: 12px; padding: 14px; font-size: .95rem; resize: vertical;
  transition: border-color .16s;
}
.transcript.live { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-ring); }
textarea.writer {
  width: 100%; min-height: 260px; background: var(--surface); color: var(--text);
  border: 1px solid var(--line); border-radius: 12px; padding: 16px; font-size: .95rem; line-height: 1.7; resize: vertical;
}
textarea.writer:focus, .transcript:focus, input:focus, select:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-ring); }
.wc { color: var(--dim); font-size: .8rem; text-align: right; margin-top: 7px; font-variant-numeric: tabular-nums; }
.wc.warn { color: var(--amber); }

/* level meter + dictation */
.meter-wrap { width: 100%; max-width: 320px; }
.meter-track { height: 8px; background: var(--surface); border: 1px solid var(--line); border-radius: 999px; overflow: hidden; }
.meter-fill { height: 100%; width: 0%; border-radius: 999px; background: linear-gradient(90deg, var(--green), var(--accent)); transition: width .08s linear; }
.rec-status { font-size: .82rem; min-height: 1.2em; text-align: center; color: var(--dim); }
.rec-status.err { color: var(--red); }
.rec-status.ok { color: var(--green); }
.playback-row { width: 100%; display: flex; justify-content: center; margin-top: 6px; }
.playback-row audio { height: 38px; max-width: 100%; border-radius: 10px; }
.dict-controls { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; margin-bottom: 14px; }
.dict-controls .btn.playing { box-shadow: 0 0 0 3px var(--accent-ring); }
.replay-count { text-align: center; color: var(--dim); font-size: .8rem; margin-bottom: 10px; font-variant-numeric: tabular-nums; }

/* ---------- Feedback ---------- */
.score-hero { display: flex; align-items: center; gap: 30px; margin-bottom: 16px; }
.score-ring {
  --p: 0; width: 128px; height: 128px; border-radius: 50%; flex-shrink: 0;
  background: conic-gradient(var(--accent) calc(var(--p) * 1%), var(--elev2) 0);
  display: grid; place-items: center; position: relative;
  transition: all .8s ease;
}
.score-ring::before { content: ""; position: absolute; inset: 10px; border-radius: 50%; background: var(--panel); }
.score-ring .num { position: relative; font-family: var(--font-display); font-size: 2rem; font-weight: 700; }
.score-ring .num small { font-size: .85rem; color: var(--dim); font-weight: 500; }
.band-line { font-size: 1rem; margin-bottom: 4px; }
.band-line b { color: var(--accent-hi); font-family: var(--font-display); }
.bars { display: flex; flex-direction: column; gap: 10px; margin-top: 12px; }
.bar-row { display: grid; grid-template-columns: 132px 1fr 34px; gap: 12px; align-items: center; font-size: .83rem; color: var(--muted); }
.bar-row b { color: var(--text); font-variant-numeric: tabular-nums; text-align: right; }
.bar-track { height: 6px; background: var(--surface); border: 1px solid var(--line); border-radius: 999px; overflow: hidden; }
.bar-fill { height: 100%; border-radius: 999px; background: linear-gradient(90deg, var(--accent), var(--accent-hi)); transition: width .7s cubic-bezier(.22,1,.36,1); }
.fb-grid { display: grid; grid-template-columns: 1.3fr .7fr; gap: 14px; align-items: start; }
.fb-col { display: flex; flex-direction: column; gap: 14px; }

.issue { padding: 13px 15px; border-left: 3px solid var(--amber); background: var(--surface); border-radius: 10px; margin-bottom: 10px; font-size: .88rem; line-height: 1.55; }
.issue.bad { border-left-color: var(--red); }
.issue.good { border-left-color: var(--green); }
.issue .q { color: var(--dim); font-size: .8rem; margin-top: 5px; }
.issue code { background: var(--elev2); padding: 2px 8px; border-radius: 6px; font-family: "JetBrains Mono", Consolas, monospace; font-size: .82em; color: var(--green); }
.upgrade-word {
  display: inline-flex; align-items: center; gap: 8px; margin: 4px 6px 4px 0; padding: 6px 13px;
  background: var(--surface); border: 1px solid var(--line-2); border-radius: 999px; font-size: .83rem;
  cursor: pointer; transition: .15s; color: var(--muted);
}
.upgrade-word:hover { border-color: var(--green); color: var(--text); }
.model-answer { color: var(--muted); font-size: .9rem; line-height: 1.7; font-style: italic; }
.fb-actions { display: flex; gap: 10px; margin-top: 18px; flex-wrap: wrap; }

/* ---------- Progress ---------- */
.prog-grid { display: grid; grid-template-columns: 1.2fr .8fr; gap: 14px; margin-bottom: 14px; }
#trendChart { width: 100%; height: 180px; }
.hist-row { display: grid; grid-template-columns: 84px 1fr auto; gap: 14px; align-items: center; padding: 12px 2px; border-bottom: 1px solid var(--line); font-size: .88rem; }
.hist-row:last-child { border-bottom: none; }
.hist-score { font-family: var(--font-display); font-weight: 700; }

/* ---------- Vocab ---------- */
.search-input { background: var(--surface); border: 1px solid var(--line); color: var(--text); padding: 10px 16px; border-radius: 999px; width: 240px; font-size: .9rem; }
.search-input::placeholder { color: var(--dim); }
.vocab-tabs { display: flex; gap: 6px; margin-bottom: 18px; flex-wrap: wrap; background: var(--surface); border: 1px solid var(--line); padding: 4px; border-radius: 999px; width: fit-content; }
.vtab { padding: 7px 18px; border-radius: 999px; color: var(--dim); font-size: .85rem; font-weight: 500; transition: .15s; }
.vtab:hover { color: var(--text); }
.vtab.active { background: var(--accent); color: #fff; font-weight: 600; box-shadow: 0 2px 10px rgba(99,102,241,.35); }
.vocab-item { display: flex; gap: 14px; align-items: flex-start; padding: 15px 2px; border-bottom: 1px solid var(--line); }
.vocab-item:last-child { border-bottom: none; }
.vocab-item .phrase { font-weight: 600; font-size: .95rem; }
.vocab-item .mean { color: var(--muted); font-size: .86rem; margin-top: 3px; }
.vocab-item .ex { color: var(--dim); font-size: .84rem; font-style: italic; margin-top: 4px; }
.vocab-side { margin-left: auto; display: flex; flex-direction: column; align-items: flex-end; gap: 7px; flex-shrink: 0; }
.known-btn { font-size: .74rem; padding: 5px 13px; border-radius: 999px; border: 1px solid var(--line-2); color: var(--dim); transition: .15s; }
.known-btn:hover { color: var(--text); border-color: var(--dim); }
.known-btn.on { color: var(--green); border-color: rgba(52,211,153,.45); background: var(--green-soft); }
.rm-btn { color: var(--dim); font-size: .76rem; } .rm-btn:hover { color: var(--red); }

/* ---------- Modal / toast ---------- */
.modal-backdrop {
  position: fixed; inset: 0; background: rgba(0,0,0,.7); backdrop-filter: blur(6px);
  display: grid; place-items: center; z-index: 50; padding: 20px;
}
.modal-backdrop.hidden { display: none; }
.modal {
  width: 560px; max-width: 100%; background: var(--panel); border: 1px solid var(--line-2);
  border-radius: 20px; padding: 30px; box-shadow: 0 24px 80px rgba(0,0,0,.6);
  max-height: 88vh; overflow: auto;
}
.modal h2 { margin-bottom: 8px; font-size: 1.3rem; }
.modal-actions { display: flex; gap: 10px; justify-content: flex-end; margin-top: 24px; }
.field { display: block; margin-top: 16px; }
.field > span { display: block; font-size: .82rem; color: var(--muted); margin-bottom: 7px; font-weight: 500; }
.field input, .field select { width: 100%; background: var(--surface); border: 1px solid var(--line); color: var(--text); border-radius: var(--radius-sm); padding: 11px 14px; }
.pill-row { display: flex; gap: 8px; }
.pill { flex: 1; padding: 10px; border-radius: var(--radius-sm); border: 1px solid var(--line); color: var(--muted); font-family: var(--font-display); font-weight: 600; transition: .15s; }
.pill:hover { border-color: var(--dim); color: var(--text); }
.pill.sel { background: var(--accent-soft); border-color: var(--accent); color: var(--accent-hi); }
.quiz-q { margin-top: 16px; padding: 15px; background: var(--surface); border-radius: 12px; border: 1px solid var(--line); }
.quiz-q .qtext { font-size: .93rem; margin-bottom: 10px; }
.quiz-opts { display: flex; flex-direction: column; gap: 7px; }
.quiz-opt { text-align: left; padding: 10px 13px; border-radius: 9px; border: 1px solid var(--line); color: var(--muted); font-size: .87rem; transition: .15s; }
.quiz-opt:hover { border-color: var(--dim); }
.quiz-opt.sel { border-color: var(--accent); color: var(--text); background: var(--accent-soft); }

.toast {
  position: fixed; bottom: 28px; left: 50%; transform: translateX(-50%) translateY(80px);
  background: var(--elev2); border: 1px solid var(--line-2); color: var(--text);
  padding: 12px 22px; border-radius: 12px; box-shadow: 0 16px 48px rgba(0,0,0,.55);
  opacity: 0; transition: .3s cubic-bezier(.22,1,.36,1); z-index: 99; pointer-events: none; font-size: .9rem;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ---------- Responsive ---------- */
/* Mobile chrome: hidden on desktop */
.mobile-topbar { display: none; }
.bottom-nav { display: none; }

@media (max-width: 900px) {
  .sidebar { width: 74px; padding: 16px 8px; }
  .brand-name, .brand-sub, .nav-label, .user-chip, #editProfileBtn { display: none; }
  .nav-item { justify-content: center; padding: 10px 0; }
  .nav-item.active::before { left: -8px; }
  .main { padding: 22px 16px 60px; }
  .stat-row { grid-template-columns: 1fr 1fr; }
  .fb-grid, .prog-grid { grid-template-columns: 1fr; }
  .score-hero { flex-direction: column; text-align: center; }
  .bar-row { grid-template-columns: 110px 1fr 32px; }
}

/* =========================================================
   Smartphone mode (Android-first): bottom tab bar, top bar,
   bottom-sheet modals, 44px+ touch targets, safe-area insets.
   ========================================================= */
@media (max-width: 640px) {
  .sidebar { display: none; }

  .mobile-topbar {
    display: flex; align-items: center; justify-content: space-between; gap: 10px;
    position: fixed; top: 0; left: 0; right: 0; z-index: 40;
    padding: calc(8px + env(safe-area-inset-top)) 14px 8px;
    background: rgba(9,9,11,.86); backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--line);
  }
  .mobile-topbar .brand { padding: 0; gap: 9px; }
  .mobile-topbar .brand-logo { width: 30px; height: 30px; border-radius: 9px; font-size: .72rem; }
  .mobile-topbar .brand-name { font-size: .95rem; }
  .m-top-right { display: flex; align-items: center; gap: 8px; }
  .mobile-topbar .level-badge { padding: 5px 12px; font-size: .78rem; }
  .m-edit {
    width: 38px; height: 38px; border-radius: 11px; display: grid; place-items: center;
    background: var(--panel); border: 1px solid var(--line); color: var(--muted); font-size: 1rem;
  }
  .m-edit:active { background: var(--elev2); color: var(--text); }

  .bottom-nav {
    display: grid; grid-template-columns: repeat(4, 1fr);
    position: fixed; bottom: 0; left: 0; right: 0; z-index: 40;
    background: rgba(15,15,18,.92); backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
    border-top: 1px solid var(--line);
    padding: 4px 6px calc(4px + env(safe-area-inset-bottom));
  }
  .bnav-item {
    display: flex; flex-direction: column; align-items: center; gap: 3px;
    min-height: 52px; padding: 6px 0 4px; border-radius: 14px;
    color: var(--dim); font-size: .64rem; font-weight: 500; letter-spacing: .01em; transition: .15s;
  }
  .bnav-ico {
    width: 44px; height: 26px; border-radius: 999px; display: grid; place-items: center;
    font-size: .82rem; transition: .18s;
  }
  .bnav-item:active { transform: scale(.94); }
  .bnav-item.active { color: var(--accent-hi); font-weight: 700; }
  .bnav-item.active .bnav-ico { background: var(--accent-soft); color: var(--accent-hi); }

  .main { padding: calc(66px + env(safe-area-inset-top)) 14px calc(86px + env(safe-area-inset-bottom)); }

  /* headers */
  .view-head { flex-direction: column; gap: 12px; margin-bottom: 18px; }
  .view-head h1 { font-size: 1.3rem; }
  #view-home .level-badge { display: none; } /* already in top bar */
  .search-input { width: 100%; min-height: 44px; font-size: 16px; }

  /* cards & grids */
  .card { padding: 16px; border-radius: 14px; }
  .stat-row { gap: 10px; margin-bottom: 16px; }
  .stat { padding: 14px; }
  .stat .v { font-size: 1.3rem; }
  .home-grid { grid-template-columns: 1fr; gap: 10px; }
  .quick-card { padding: 15px 16px; }
  .quick-ico { width: 42px; height: 42px; font-size: 1.15rem; }
  .practice-grid { grid-template-columns: 1fr; gap: 10px; }
  .task-card { padding: 16px; }
  .rec-item { padding: 14px 12px; }

  /* category filter: horizontal snap-scroll strip */
  .filter-row {
    flex-wrap: nowrap; overflow-x: auto; scrollbar-width: none;
    margin: 0 -14px 16px; padding: 2px 14px 6px;
    -webkit-overflow-scrolling: touch; scroll-snap-type: x proximity;
  }
  .filter-row::-webkit-scrollbar { display: none; }
  .fchip { flex-shrink: 0; scroll-snap-align: start; padding: 9px 16px; min-height: 38px; font-size: .82rem; }

  /* practice screens */
  .crumb { font-size: .8rem; margin-bottom: 14px; }
  .read-text { font-size: 1.08rem; padding: 22px 6px; line-height: 1.75; }
  .prompt-box { padding: 14px; font-size: .95rem; }
  .btn { min-height: 46px; }
  .btn.big { width: 100%; justify-content: center; }
  textarea.writer { min-height: 220px; font-size: 16px; }
  .transcript { font-size: 16px; min-height: 110px; }
  .dict-controls { gap: 8px; }
  .dict-controls .btn { flex: 1 1 40%; justify-content: center; }
  .recorder { padding: 16px 0 4px; }
  .playback-row audio { width: 100%; }

  /* feedback */
  .score-hero { gap: 16px; margin-bottom: 12px; }
  .score-ring { width: 112px; height: 112px; }
  .score-ring .num { font-size: 1.7rem; }
  .bar-row { grid-template-columns: 96px 1fr 30px; gap: 8px; font-size: .78rem; }
  .fb-actions { flex-direction: column; }
  .fb-actions .btn { width: 100%; justify-content: center; }
  .upgrade-word { padding: 9px 14px; }

  /* progress */
  #trendChart { height: 150px; }
  .hist-row { grid-template-columns: 60px 1fr auto; gap: 10px; font-size: .82rem; padding: 11px 2px; }

  /* vocab */
  .vocab-tabs { width: 100%; overflow-x: auto; flex-wrap: nowrap; scrollbar-width: none; -webkit-overflow-scrolling: touch; }
  .vocab-tabs::-webkit-scrollbar { display: none; }
  .vtab { padding: 9px 15px; white-space: nowrap; min-height: 38px; }
  .vocab-item { padding: 14px 2px; gap: 10px; }
  .known-btn { padding: 8px 14px; }

  /* bottom-sheet modal (smartphone UX standard) */
  .modal-backdrop { display: flex; align-items: flex-end; justify-content: center; padding: 0; }
  .modal {
    width: 100%; max-width: none; border-radius: 22px 22px 0 0; border-bottom: none;
    padding: 24px 18px calc(22px + env(safe-area-inset-bottom));
    max-height: 92dvh;
  }
  .modal h2 { font-size: 1.15rem; }
  .modal-actions { flex-direction: column-reverse; gap: 8px; margin-top: 20px; }
  .modal-actions .btn { width: 100%; justify-content: center; min-height: 48px; }
  .field input { font-size: 16px; min-height: 46px; }
  .pill { min-height: 46px; }
  .quiz-opt { padding: 13px; font-size: .9rem; }

  .toast { bottom: calc(96px + env(safe-area-inset-bottom)); left: 16px; right: 16px; transform: translateY(90px); text-align: center; }
  .toast.show { transform: translateY(0); }
}