:root{
  --navy:#1f3864; --blue:#2e5496; --blue2:#3d6bc4; --green:#3a8a4f; --green-l:#e2efda;
  --gold:#bf9000; --gold-l:#fff2cc; --orange:#c55a11; --orange-l:#fce4d6;
  --bg:#f4f6fb; --card:#ffffff; --ink:#1d2433; --muted:#6b7280; --line:#e3e8f0;
  --shadow:0 2px 14px rgba(31,56,100,.08);
}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html,body{margin:0;padding:0}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Arial,sans-serif;
  background:var(--bg);color:var(--ink);line-height:1.5;padding-bottom:78px;font-size:15px}
header{background:linear-gradient(135deg,var(--navy),var(--blue));color:#fff;padding:16px 18px 14px;
  position:sticky;top:0;z-index:20;box-shadow:0 2px 10px rgba(0,0,0,.12)}
header h1{margin:0;font-size:18px;font-weight:700;letter-spacing:.2px}
header p{margin:3px 0 0;font-size:12.5px;opacity:.85}
.wrap{max-width:680px;margin:0 auto;padding:16px}
.card{background:var(--card);border-radius:16px;padding:16px;box-shadow:var(--shadow);margin-bottom:14px;border:1px solid var(--line)}
.card h2{margin:0 0 4px;font-size:16px}
.card h3{margin:14px 0 8px;font-size:14px;color:var(--navy)}
.muted{color:var(--muted);font-size:13px}
.pill{display:inline-block;padding:3px 10px;border-radius:999px;font-size:12px;font-weight:600}
.p1{background:var(--green-l);color:var(--green)}
.p2{background:var(--gold-l);color:var(--gold)}
.p3{background:var(--orange-l);color:var(--orange)}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;border:none;cursor:pointer;
  background:var(--blue);color:#fff;font-weight:600;font-size:14px;padding:11px 16px;border-radius:12px;transition:.15s}
.btn:active{transform:scale(.97)}
.btn.ghost{background:#eef2fb;color:var(--blue)}
.btn.green{background:var(--green)} .btn.gold{background:var(--gold)} .btn.orange{background:var(--orange)}
.btn.sm{padding:8px 12px;font-size:13px;border-radius:10px}
.row{display:flex;gap:8px;flex-wrap:wrap}
.grow{flex:1}
.part{display:flex;align-items:center;gap:12px;padding:12px;border:1px solid var(--line);border-radius:12px;margin-bottom:9px;background:#fbfcfe}
.part .ic{width:38px;height:38px;border-radius:10px;display:flex;align-items:center;justify-content:center;font-size:19px;flex-shrink:0}
.part .tt{flex:1;min-width:0}
.part .tt b{font-size:14px} .part .tt div{font-size:12.5px;color:var(--muted)}
.chk{width:26px;height:26px;border-radius:8px;border:2px solid var(--line);cursor:pointer;display:flex;align-items:center;justify-content:center;font-size:16px;color:#fff;flex-shrink:0;background:#fff;transition:.15s}
.chk.on{background:var(--green);border-color:var(--green)}
.bar{height:12px;background:#e9edf5;border-radius:99px;overflow:hidden}
.bar > i{display:block;height:100%;background:linear-gradient(90deg,var(--green),#5cb36f);border-radius:99px;transition:.4s}
.stats{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin:6px 0 4px}
.stat{background:#fbfcfe;border:1px solid var(--line);border-radius:12px;padding:12px 8px;text-align:center}
.stat b{display:block;font-size:22px;color:var(--navy)} .stat span{font-size:11.5px;color:var(--muted)}
.timerbox{text-align:center;padding:6px 0}
.clock{font-size:48px;font-weight:800;font-variant-numeric:tabular-nums;color:var(--navy);letter-spacing:1px}
.flash{perspective:1000px;height:180px;margin-bottom:12px}
.flash-in{position:relative;width:100%;height:100%;transition:transform .5s;transform-style:preserve-3d;cursor:pointer}
.flash.flip .flash-in{transform:rotateY(180deg)}
.face{position:absolute;inset:0;backface-visibility:hidden;border-radius:14px;display:flex;flex-direction:column;
  align-items:center;justify-content:center;padding:16px;text-align:center;border:1px solid var(--line)}
.front{background:linear-gradient(135deg,#eef3fc,#fff)}
.back{background:linear-gradient(135deg,#eafaf0,#fff);transform:rotateY(180deg)}
.face .w{font-size:26px;font-weight:800;color:var(--navy)}
.face .ipa{color:var(--blue);font-size:15px;margin-top:4px}
.prompt-txt{font-size:19px;font-weight:600;line-height:1.45;margin:6px 0 2px}
.tag{font-size:12px;color:var(--muted);text-transform:uppercase;letter-spacing:.5px;font-weight:700}
ul.clean{margin:6px 0;padding-left:18px} ul.clean li{margin-bottom:5px;font-size:13.5px}
a{color:var(--blue);text-decoration:none;font-weight:600}
.wk{border:1px solid var(--line);border-radius:12px;margin-bottom:8px;overflow:hidden}
.wk summary{list-style:none;cursor:pointer;padding:11px 13px;display:flex;align-items:center;gap:10px;font-weight:600;font-size:14px}
.wk summary::-webkit-details-marker{display:none}
.wk[open] summary{background:#f6f8fd}
.wk .body{padding:2px 14px 13px;font-size:13.5px}
.wk .body b{color:var(--navy)}
.wk .num{width:30px;height:30px;border-radius:9px;display:flex;align-items:center;justify-content:center;font-weight:800;color:#fff;flex-shrink:0}
nav{position:fixed;bottom:0;left:0;right:0;background:#fff;border-top:1px solid var(--line);display:flex;z-index:30;
  box-shadow:0 -2px 14px rgba(31,56,100,.07);padding-bottom:env(safe-area-inset-bottom)}
nav button{position:relative;flex:1;border:none;background:none;padding:9px 2px 8px;cursor:pointer;color:var(--muted);font-size:10.5px;font-weight:600;display:flex;flex-direction:column;align-items:center;gap:3px}
nav button .ni{font-size:20px}
nav button.on{color:var(--blue)}
.hidden{display:none}
.banner{background:var(--gold-l);border:1px solid #f0e0a8;color:#7a5c00;border-radius:12px;padding:10px 12px;font-size:13px;margin-bottom:12px}
label.fld{display:block;font-size:12.5px;color:var(--muted);margin:8px 0 4px;font-weight:600}
input[type=date],input[type=number]{width:100%;padding:10px;border:1px solid var(--line);border-radius:10px;font-size:15px;font-family:inherit}
.mini{display:flex;gap:8px;align-items:center}
.rate{display:flex;gap:5px;flex-wrap:wrap}
.rate button{width:30px;height:30px;border-radius:8px;border:1px solid var(--line);background:#fff;font-weight:700;cursor:pointer;font-size:13px}
.rate button.on{background:var(--blue);color:#fff;border-color:var(--blue)}
select{width:100%;padding:10px;border:1px solid var(--line);border-radius:10px;font-size:14px;font-family:inherit;background:#fff}
input[type=range]{accent-color:var(--blue)}
.btn.ghost.sm.on{background:var(--gold);color:#fff}
/* Đáp án mẫu (Luyện nhanh) */
.answer{margin-top:10px;background:#eafaf0;border:1px solid #bfe6cd;border-radius:12px;padding:12px;font-size:14px;line-height:1.55}
.answer b{color:var(--green)}
/* Bài nghe */
.sent{border:1px solid var(--line);border-radius:12px;padding:10px;margin-bottom:9px;background:#fbfcfe;transition:.15s}
.sent.playing{background:var(--gold-l);border-color:#f0e0a8}
.srow{display:flex;gap:10px;align-items:flex-start}
.srow .stxt{flex:1;min-width:0}
.srow .en{font-size:15.5px;font-weight:600;line-height:1.5}
.srow .vi{font-size:13px;margin-top:2px}
.hideText .en{filter:blur(5px);transition:.15s} .hideText .en:hover,.hideText .en:active{filter:none}
.hideText .vi{display:none}
.dict{flex:1;min-width:0;padding:9px 10px;border:1px solid var(--line);border-radius:10px;font-size:14px;font-family:inherit}
.dchk{margin-top:6px;font-size:13px;line-height:1.5}
.dchk.ok{color:var(--green);font-weight:600}
.dchk.warn{color:var(--orange)}
.dchk .gok{color:var(--green)} .dchk .gno{color:#c0392b;text-decoration:underline}

/* ---------- Nguồn nghe thật ---------- */
.src-item{padding:8px 0;border-top:1px dashed var(--line)}
.src-item:first-child{border-top:none}
.src-item a{font-size:14px}
.src-item .muted{font-size:12px;margin-top:2px}
.src-why{font-size:12.5px;color:var(--ink);margin-top:3px}

/* ---------- Chấm phát âm ---------- */
.pron{margin-top:8px;font-size:13px;line-height:1.55;padding:9px 11px;border-radius:10px;border:1px solid var(--line)}
.pron:empty{display:none}
.pron.muted{color:var(--muted)}
.pron.ok{background:var(--green-l);border-color:#bfe6cd;color:var(--ink)}
.pron.warn{background:var(--gold-l);border-color:#f0e0a8;color:var(--ink)}
.pron.bad{background:var(--orange-l);border-color:#f0c8a8;color:var(--ink)}
.pron .gok{color:var(--green);font-weight:600} .pron .gno{color:#c0392b;text-decoration:underline}

/* ---------- Ghi âm ---------- */
.rec-audio{width:100%;margin-top:10px;display:block}
.btn.rec{background:var(--orange);animation:recpulse 1.1s ease-in-out infinite}
@keyframes recpulse{0%,100%{box-shadow:0 0 0 0 rgba(197,90,17,.5)}50%{box-shadow:0 0 0 8px rgba(197,90,17,0)}}
.rec-item{border:1px solid var(--line);border-radius:12px;padding:10px;margin-bottom:9px;background:#fbfcfe}
.rec-meta{display:flex;flex-direction:column;gap:2px;margin-bottom:6px}
.rec-meta b{font-size:13.5px;line-height:1.35}
.rec-meta .muted{font-size:12px}
.rec-item audio{width:100%;height:36px;display:block}
.rec-actions{display:flex;gap:8px;justify-content:flex-end;margin-top:6px;flex-wrap:wrap}
.rec-item.pinned{border-color:var(--gold);background:var(--gold-l)}
.rec-note{display:block;font-size:12.5px;color:var(--ink);font-weight:600;margin-top:2px}
:root[data-theme="dark"] .rec-item{background:#131b28}
:root[data-theme="dark"] .rec-item.pinned{background:#2a2413}
/* Vùng dung lượng ghi âm */
.rec-usage{margin-bottom:12px}
/* Nhóm bản ghi (theo bài / theo ngày) */
.rec-group{margin-bottom:14px}
.rec-ghead{display:flex;align-items:center;gap:8px;margin-bottom:8px;font-size:13.5px;line-height:1.35}
.rec-ghead b{flex:1;min-width:0}
.cmp-btn{flex-shrink:0}
/* Panel so sánh đầu ↔ mới nhất */
.rec-cmp{border:1px dashed var(--blue2);border-radius:12px;padding:10px;margin-bottom:9px;background:#eef3fc}
.cmp-cols{display:flex;gap:10px}
.cmp-col{flex:1;min-width:0}
.cmp-lbl{font-size:12px;color:var(--muted);margin-bottom:4px;font-weight:600}
.cmp-sel{width:100%;padding:6px 8px;font-size:12.5px;border:1px solid var(--line);border-radius:8px;margin-bottom:6px;background:#fff}
.cmp-col audio{width:100%;height:34px}
:root[data-theme="dark"] .cmp-sel{background:#131b28;color:var(--ink)}
:root[data-theme="dark"] .rec-cmp{background:#131b28}

/* ---------- Biểu đồ tiến độ (SVG) ---------- */
.chart-wrap{width:100%;overflow-x:auto}
.chart-svg{width:100%;height:auto;display:block}
.chart-svg .bar{fill:var(--blue2)}
.chart-svg .bar-goal{fill:var(--green)}
.chart-svg .bar-today{fill:var(--gold)}
.chart-svg .bar-empty{fill:var(--line)}
.chart-svg .goal-line{stroke:var(--green);stroke-width:1;stroke-dasharray:3 3;opacity:.55}
.chart-svg .bar-lbl{fill:var(--muted);font-size:8px}
.chart-svg .rate-l{stroke:var(--green);fill:var(--green);stroke-width:2}
.chart-svg .rate-s{stroke:var(--orange);fill:var(--orange);stroke-width:2}
/* Thống kê spaced repetition */
.srsdist{display:flex;gap:6px;align-items:flex-end;height:88px;margin-top:10px}
.srsbar{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:flex-end;height:100%}
.srsbar i{display:block;width:70%;min-height:3px;background:var(--blue2);border-radius:4px 4px 0 0}
.srsbar b{font-size:13px;margin-top:3px;color:var(--navy)}
.srsbar span{font-size:10px;color:var(--muted)}
/* Huy hiệu số thẻ tới hạn trên nav */
.navbadge{position:absolute;top:3px;left:calc(50% + 6px);background:var(--orange);color:#fff;font-size:9px;font-weight:800;min-width:15px;height:15px;line-height:15px;text-align:center;border-radius:8px;padding:0 3px}

/* ============================================================
 * 🌙 CHẾ ĐỘ TỐI — ghi đè biến màu + các nền sáng cứng.
 * ============================================================ */
:root[data-theme="dark"]{
  color-scheme:dark;
  --navy:#a8c4ff; --blue:#5b8def; --blue2:#5b8def;
  --green:#5cc47a; --green-l:#16301f;
  --gold:#e0b74e; --gold-l:#332b12;
  --orange:#e08a4f; --orange-l:#33220f;
  --bg:#0f1626; --card:#18202f; --ink:#e7ecf5; --muted:#93a1b8; --line:#28324a;
  --shadow:0 2px 14px rgba(0,0,0,.4);
}
:root[data-theme="dark"] header{background:linear-gradient(135deg,#141b2e,#20305a)}
:root[data-theme="dark"] nav{background:#141b29}
:root[data-theme="dark"] .part,
:root[data-theme="dark"] .stat,
:root[data-theme="dark"] .sent,
:root[data-theme="dark"] .chk,
:root[data-theme="dark"] .wk[open] summary{background:#131b28}
:root[data-theme="dark"] .btn.ghost{background:#232e46;color:var(--navy)}
:root[data-theme="dark"] .bar{background:#232e46}
:root[data-theme="dark"] .front{background:linear-gradient(135deg,#1d2740,#18202f)}
:root[data-theme="dark"] .back{background:linear-gradient(135deg,#16301f,#18202f)}
:root[data-theme="dark"] .answer{background:#16301f;border-color:#255138}
:root[data-theme="dark"] .banner{color:#e7d9a6}
:root[data-theme="dark"] input,
:root[data-theme="dark"] select,
:root[data-theme="dark"] textarea,
:root[data-theme="dark"] .dict,
:root[data-theme="dark"] .rate button{background:#131b28;color:var(--ink);border-color:var(--line)}
:root[data-theme="dark"] .sent.playing{background:#332b12;border-color:#5a4d1e}