:root{
  color-scheme:dark;
  --bg:#061429;
  --bg-deep:#031022;
  --surface:#0b1d38;
  --surface-strong:#0e2546;
  --surface-soft:#102b50;
  --border:#294769;
  --border-soft:rgba(112,148,188,.24);
  --text:#f4f8ff;
  --muted:#9badc3;
  --accent:#367dff;
  --accent-2:#7047f8;
  --cyan:#22d3ee;
  --green:#31d4a0;
  --red:#fb7185;
  --orange:#fb923c;
  --shadow:0 24px 65px rgba(0,0,0,.32);
  --radius:22px;
  --font-ui:"Segoe UI","Microsoft YaHei UI","Microsoft YaHei",system-ui,sans-serif;
  --font-en:"Segoe UI",Inter,Arial,sans-serif;
}

*{box-sizing:border-box}
.sr-only{position:absolute!important;width:1px!important;height:1px!important;padding:0!important;margin:-1px!important;overflow:hidden!important;clip:rect(0,0,0,0)!important;white-space:nowrap!important;border:0!important}
html{min-width:320px;background:var(--bg-deep)}
body{min-height:100vh;margin:0;color:var(--text);font-family:var(--font-ui);background:
  radial-gradient(circle at 16% -10%,rgba(55,125,255,.18),transparent 32%),
  radial-gradient(circle at 93% 90%,rgba(112,71,248,.12),transparent 30%),
  linear-gradient(150deg,var(--bg-deep),var(--bg) 42%,#071a36)}
button,input,textarea{font:inherit}
button,a{outline-offset:4px}
button{color:inherit}
button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible{outline:3px solid rgba(34,211,238,.75)}

.site-header{height:78px;padding:0 clamp(20px,3.2vw,52px);display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--border-soft);background:rgba(4,17,36,.78);backdrop-filter:blur(18px);position:sticky;top:0;z-index:20}
.brand{color:#fff;text-decoration:none;font-size:25px;font-weight:800;letter-spacing:.04em}
.header-nav{display:flex;align-items:center;gap:24px}
.header-nav a{color:#b9c7d9;text-decoration:none;font-size:15px;transition:color .18s ease}
.header-nav a:hover{color:#fff}

.app-shell{width:min(1540px,calc(100% - 44px));margin:24px auto 18px;display:grid;grid-template-columns:300px minmax(500px,1fr) 270px;gap:20px;align-items:stretch}
.practice-sidebar,.practice-panel,.stats-sidebar{border:1px solid var(--border);border-radius:var(--radius);background:linear-gradient(145deg,rgba(15,39,72,.95),rgba(7,25,50,.96));box-shadow:var(--shadow)}
.practice-sidebar,.stats-sidebar{padding:25px 21px}
.practice-panel{min-height:690px;padding:30px 32px 20px;display:flex;flex-direction:column}

.library-heading{padding:0 2px 22px;border-bottom:1px solid var(--border-soft)}
.library-label{margin:0 0 7px;color:var(--cyan);font-size:12px;font-weight:700;letter-spacing:.12em}
.library-heading h1{margin:0;font-size:26px;line-height:1.28}
.sentence-total{display:flex;align-items:baseline;gap:8px;margin:17px 0 5px}
.sentence-total strong{font:800 45px/1 var(--font-en);letter-spacing:.02em}
.sentence-total span{color:#d4deec;font-size:15px;font-weight:700}
.library-heading>p:last-child{margin:10px 0 0;color:var(--muted);font-size:13px}
.mode-section,.overall-section{padding-top:22px}
.mode-section h2,.overall-section h2,.stats-sidebar h2{margin:0 0 14px;color:#c7d3e2;font-size:14px;font-weight:700;letter-spacing:.06em}
.mode-list{display:grid;gap:9px}
.mode-button{width:100%;border:1px solid var(--border-soft);border-radius:13px;padding:13px 12px;background:rgba(5,21,44,.58);display:flex;align-items:center;gap:11px;text-align:left;cursor:pointer;transition:transform .16s ease,border-color .16s ease,background .16s ease}
.mode-button:hover{transform:translateX(3px);border-color:#4c729c}
.mode-button.is-active{border-color:#3a89ff;background:linear-gradient(110deg,#1b8af1,#6046e8);box-shadow:0 10px 25px rgba(44,104,232,.25)}
.mode-icon{width:38px;height:38px;display:grid;place-items:center;flex:0 0 auto;border-radius:10px;background:rgba(255,255,255,.1);font:700 23px/1 var(--font-en)}
.mode-button strong{display:block;font-size:15px}
.mode-button small{display:block;margin-top:3px;color:#9fb3ca;font-size:11px;line-height:1.35}
.mode-button.is-active small{color:#d9e6fb}

.overall-section{margin-top:4px;border-top:1px solid var(--border-soft)}
.progress-overview{display:grid;grid-template-columns:110px 1fr;gap:15px;align-items:center}
.progress-ring{width:104px;height:104px;border-radius:50%;display:grid;place-content:center;text-align:center;position:relative;background:conic-gradient(var(--accent) 0 var(--progress),#233a58 var(--progress) 360deg)}
.progress-ring::after{content:"";position:absolute;inset:10px;border-radius:50%;background:#0b1e39}
.progress-ring strong,.progress-ring span{position:relative;z-index:1}
.progress-ring strong{font:800 25px/1.1 var(--font-en)}
.progress-ring span{margin-top:4px;color:var(--muted);font-size:11px}
.progress-overview dl{margin:0;display:grid;gap:9px}
.progress-overview dl div{display:flex;align-items:center;justify-content:space-between;gap:8px}
.progress-overview dt{color:var(--muted);font-size:12px}
.progress-overview dd{margin:0;font:700 13px/1 var(--font-en)}
.secondary-button,.primary-button{border:0;border-radius:12px;cursor:pointer;transition:transform .16s ease,filter .16s ease,opacity .16s ease}
.secondary-button{background:#102b4f;border:1px solid #36577c;color:#e7eef8}
.secondary-button:hover,.primary-button:hover{transform:translateY(-1px);filter:brightness(1.08)}
.mistake-button{width:100%;margin-top:18px;padding:12px 14px;display:flex;align-items:center;justify-content:space-between;font-size:13px;font-weight:700}
.mistake-button span{font-size:22px}
.jump-control{display:block;margin-top:17px;color:var(--muted);font-size:12px}
.jump-field{display:flex;margin-top:7px}
.jump-field input{min-width:0;width:100%;height:39px;border:1px solid #35567a;border-radius:10px 0 0 10px;padding:0 10px;color:#fff;background:#06162d}
.jump-field button{width:58px;border:0;border-radius:0 10px 10px 0;color:#fff;background:#315f9a;cursor:pointer;font-size:12px;font-weight:700}

.practice-topline{display:flex;align-items:center;justify-content:space-between;gap:18px}
.practice-topline h2{margin:0;font:800 21px/1.2 var(--font-ui)}
.practice-topline p{margin:6px 0 0;color:var(--muted);font-size:12px}
.mode-status{padding:8px 13px;border:1px solid rgba(34,211,238,.4);border-radius:999px;color:var(--cyan);background:rgba(4,25,45,.7);font-size:12px;font-weight:700;white-space:nowrap}
.sentence-progress{height:8px;margin:18px 0 0;border-radius:99px;overflow:hidden;background:#263d5b}
.sentence-progress span{display:block;width:0;height:100%;border-radius:inherit;background:linear-gradient(90deg,var(--cyan),var(--accent));transition:width .3s ease}

.practice-stage{min-height:230px;padding:39px 0 24px;display:flex;flex-direction:column;justify-content:center;border-bottom:1px solid var(--border-soft)}
.stage-heading{margin:0 0 18px;display:flex;align-items:center;justify-content:space-between;gap:18px}
.stage-label{min-width:0;margin:0;color:#6d86ff;font-size:14px;font-weight:800;letter-spacing:.04em}
.primary-speak-button{min-width:164px;padding:9px 12px;border:1px solid rgba(94,207,255,.72);border-radius:13px;display:flex;align-items:center;justify-content:center;gap:10px;color:#fff;background:linear-gradient(112deg,#0a88c8,#356df4);box-shadow:0 10px 25px rgba(13,118,207,.24),inset 0 1px 0 rgba(255,255,255,.18);cursor:pointer;transition:transform .16s ease,filter .16s ease,box-shadow .16s ease}
.primary-speak-button:hover{transform:translateY(-2px);filter:brightness(1.08);box-shadow:0 14px 30px rgba(13,118,207,.32),inset 0 1px 0 rgba(255,255,255,.2)}
.primary-speak-button:active{transform:translateY(0)}
.primary-speak-button.is-speaking{background:linear-gradient(112deg,#00a785,#267df5);box-shadow:0 0 0 4px rgba(34,211,238,.12),0 14px 30px rgba(0,167,133,.25)}
.primary-speak-button.is-speaking .speak-icon{animation:speak-pulse .8s ease-in-out infinite alternate}
.speak-icon{width:36px;height:36px;border-radius:10px;display:grid;place-items:center;flex:0 0 auto;color:#fff;background:rgba(255,255,255,.13)}
.speak-icon svg{width:23px;height:23px;overflow:visible}
.speak-icon path:first-child{fill:currentColor;stroke:none}
.speak-icon path:last-child{fill:none;stroke:currentColor;stroke-width:1.8;stroke-linecap:round}
.primary-speak-button>span:last-child{display:block;text-align:left}
.primary-speak-button strong{display:block;font-size:14px;line-height:1.15}
.primary-speak-button small{display:flex;align-items:center;gap:4px;margin-top:5px;color:#d7edff;font-size:10px}
.primary-speak-button kbd{padding:1px 5px;border-color:rgba(255,255,255,.24);color:#fff;background:rgba(4,38,92,.32)}
@keyframes speak-pulse{from{transform:scale(.94);background:rgba(255,255,255,.12)}to{transform:scale(1.06);background:rgba(255,255,255,.26)}}
.target-wrap{display:flex;flex-direction:column;align-items:flex-start;gap:17px}
.target-text{margin:0;color:#f7fbff;font:500 clamp(25px,2.2vw,36px)/1.55 var(--font-en);letter-spacing:.006em;overflow-wrap:anywhere}
.target-text.is-loading{color:var(--muted)}
.target-text.is-masked{font-size:25px;letter-spacing:.08em;color:#7f95af;word-spacing:.4em}
.target-text .focus-word{color:#6688ff;font-weight:800}
.preview-button{padding:9px 14px;border:1px solid #45688d;border-radius:10px;background:#102b4f;color:#d9e7f7;cursor:pointer;font-size:12px;font-weight:700}
.preview-button.is-hidden{display:none}
.stage-note{margin:17px 0 0;color:var(--muted);font-size:13px}

.answer-form{padding-top:25px}
.answer-form>label{display:block;margin-bottom:10px;color:#56a1ff;font-size:13px;font-weight:800}
.answer-line-field{position:relative;min-height:112px;border-radius:12px;background:rgba(3,15,32,.38);transition:background .18s ease,box-shadow .18s ease}
.answer-line-field:focus-within{background:rgba(5,22,46,.66);box-shadow:0 0 0 3px rgba(55,125,255,.12)}
.answer-lines{min-height:112px;padding:16px 17px 20px;color:transparent;font:500 23px/1.85 Consolas,"Cascadia Mono","Courier New",monospace;overflow-wrap:normal;pointer-events:none;user-select:none}
.word-slots{display:inline-block;white-space:nowrap;vertical-align:top}
.char-slot,.space-slot{display:inline-block;width:1ch;height:1.48em;vertical-align:top}
.char-slot{border-bottom:2px solid #4d75a3}
.answer-line-field:focus-within .char-slot{border-bottom-color:#5d94d4}
.answer-form textarea{position:absolute;inset:0;display:block;width:100%;height:100%;min-height:112px;resize:none;border:0;padding:16px 17px 20px;color:#fff;background:transparent;caret-color:var(--cyan);font:500 23px/1.85 Consolas,"Cascadia Mono","Courier New",monospace;overflow:hidden;overflow-wrap:normal;outline:0}
.answer-form textarea:disabled{opacity:.48;cursor:not-allowed}
.answer-actions{display:flex;justify-content:center;gap:10px;margin-top:18px}
.primary-button{min-width:260px;padding:14px 22px;color:#fff;background:linear-gradient(105deg,#267df5,#7042ee);font-weight:800;box-shadow:0 12px 26px rgba(72,75,236,.22)}
.primary-button kbd{margin-left:35px;color:#b8c7e8;background:transparent;border:0}
.primary-button:disabled{opacity:.45;cursor:not-allowed;transform:none;filter:none}
.answer-actions .secondary-button{padding:13px 20px;font-weight:700}

.feedback{margin-top:13px;border:1px solid;border-radius:12px;padding:13px 15px;font-size:13px;line-height:1.6}
.feedback.is-hidden{display:none}
.feedback.is-correct{border-color:rgba(49,212,160,.65);color:#d8fff2;background:rgba(6,70,62,.28)}
.feedback.is-wrong{border-color:rgba(251,113,133,.55);color:#ffe3e8;background:rgba(94,24,46,.25)}
.feedback strong{display:block;margin-bottom:2px;color:var(--green);font-size:15px}
.feedback.is-wrong strong{color:#ff91a4}
.answer-diff{display:flex;flex-wrap:wrap;gap:5px;margin-top:8px}
.answer-diff span{padding:2px 5px;border-radius:5px;background:rgba(255,255,255,.06);font-family:var(--font-en)}
.answer-diff .wrong-word{color:#ff9aab;background:rgba(251,113,133,.14);text-decoration:underline;text-decoration-style:wavy}
.answer-diff .missing-word{color:#fcd34d;background:rgba(252,211,77,.12)}

.sentence-navigation{margin-top:auto;padding-top:21px;display:flex;align-items:center;justify-content:space-between;gap:14px;color:var(--muted);font-size:11px}
.sentence-navigation button{border:0;background:transparent;color:#b9c9dc;cursor:pointer;font-size:12px}
.sentence-navigation button:hover{color:#fff}

.stats-sidebar{display:flex;flex-direction:column;gap:23px}
.stats-sidebar section+section{padding-top:22px;border-top:1px solid var(--border-soft)}
.stat-list{display:grid;gap:2px}
.stat-row{padding:12px 7px;display:flex;align-items:center;gap:12px;border-bottom:1px solid rgba(100,134,171,.13)}
.stat-icon{width:38px;height:38px;border-radius:11px;display:grid;place-items:center;flex:0 0 auto;font:700 20px/1 var(--font-en)}
.stat-icon.blue{color:#5aa8ff;background:rgba(57,137,255,.15)}
.stat-icon.green{color:#3fe0aa;background:rgba(49,212,160,.15)}
.stat-icon.orange{color:#ff9a50;background:rgba(251,146,60,.14)}
.stat-icon.violet{color:#a586ff;background:rgba(112,71,248,.17)}
.stat-row small,.stat-row strong{display:block}
.stat-row small{color:var(--muted);font-size:11px}
.stat-row strong{margin-top:3px;font-size:14px}
.stat-row b{font:800 20px/1 var(--font-en)}
.sentence-tools{display:grid;gap:10px}
.sentence-tools h2{margin-bottom:3px}
.sentence-tools button{width:100%;padding:13px;border:1px solid var(--border-soft);border-radius:13px;background:rgba(6,22,45,.58);display:flex;align-items:center;gap:11px;text-align:left;cursor:pointer;transition:border-color .16s ease,background .16s ease}
.sentence-tools button:hover{border-color:#496f9a;background:#10294c}
.sentence-tools button>span:first-child{width:30px;color:#eaf1fb;font:700 24px/1 var(--font-en);text-align:center}
.sentence-tools strong,.sentence-tools small{display:block}
.sentence-tools strong{font-size:14px}
.sentence-tools small{margin-top:3px;color:var(--muted);font-size:10px}

.shortcut-bar{width:min(1540px,calc(100% - 44px));min-height:65px;margin:0 auto 24px;padding:14px 22px;border:1px solid var(--border-soft);border-radius:16px;display:flex;align-items:center;justify-content:center;gap:24px;flex-wrap:wrap;color:#758ba5;background:rgba(7,24,48,.72);font-size:11px}
.shortcut-bar strong{color:#4d90ff;font-size:12px}
kbd{padding:3px 7px;border:1px solid rgba(116,145,178,.2);border-radius:5px;color:#9eb1c8;background:#102640;font-family:var(--font-en);font-size:10px}

.mistake-dialog{width:min(760px,calc(100% - 30px));max-height:min(78vh,720px);border:1px solid #3a5a7c;border-radius:22px;padding:0;color:var(--text);background:#081a33;box-shadow:0 35px 100px rgba(0,0,0,.58)}
.mistake-dialog::backdrop{background:rgba(1,8,19,.75);backdrop-filter:blur(4px)}
.dialog-heading{padding:23px 25px 18px;display:flex;align-items:flex-start;justify-content:space-between;border-bottom:1px solid var(--border-soft)}
.dialog-heading p{margin:0 0 4px;color:var(--cyan);font-size:11px;font-weight:700}
.dialog-heading h2{margin:0;font-size:24px}
.dialog-heading button{border:0;background:transparent;color:#aebfd3;cursor:pointer;font-size:30px;line-height:1}
.dialog-summary{margin:17px 25px;color:var(--muted);font-size:13px}
.mistake-list{max-height:430px;padding:0 25px;overflow:auto;display:grid;gap:8px}
.mistake-item{padding:13px 14px;border:1px solid var(--border-soft);border-radius:12px;display:grid;grid-template-columns:42px 1fr auto;gap:11px;align-items:start;background:#0c2342}
.mistake-item>span{color:#6f8cac;font:700 12px/1.5 var(--font-en)}
.mistake-item p{margin:0;color:#e8eef7;font:400 14px/1.55 var(--font-en)}
.mistake-item button{border:0;background:transparent;color:#63a6ff;cursor:pointer;font-size:12px}
.dialog-actions{padding:20px 25px 25px;display:flex;justify-content:flex-end;gap:10px}
.dialog-actions button{padding:12px 16px}
.dialog-actions .primary-button{min-width:170px}
.noscript{margin:20px;text-align:center;color:#fff}

@media(max-width:1200px){
  .app-shell{grid-template-columns:270px minmax(480px,1fr)}
  .stats-sidebar{grid-column:1/-1;display:grid;grid-template-columns:1fr 1fr;padding:21px 25px}
  .stats-sidebar section+section{padding:0 0 0 24px;border-top:0;border-left:1px solid var(--border-soft)}
  .stat-list{grid-template-columns:repeat(4,1fr)}
  .stat-row{padding:8px;border-bottom:0}
  .sentence-tools{grid-template-columns:repeat(2,1fr);align-content:start}
  .sentence-tools h2{grid-column:1/-1}
}

@media(max-width:820px){
  .site-header{height:auto;min-height:66px;padding:14px 18px;gap:18px}
  .brand{font-size:21px}
  .header-nav a:first-child{display:none}
  .app-shell{width:min(100% - 24px,720px);margin-top:14px;grid-template-columns:1fr}
  .practice-panel{order:1}
  .practice-sidebar{order:2}
  .stats-sidebar{order:3}
  .practice-sidebar{display:grid;grid-template-columns:1fr 1.2fr;gap:18px;padding:20px}
  .library-heading{padding:0 18px 0 0;border:0;border-right:1px solid var(--border-soft)}
  .mode-section{padding:0}
  .overall-section{grid-column:1/-1;display:grid;grid-template-columns:1fr auto;gap:12px 18px;align-items:start}
  .overall-section h2{grid-column:1/-1}
  .progress-overview{max-width:360px}
  .mistake-button{width:190px;margin:0}
  .jump-control{grid-column:2;margin:0;width:190px}
  .practice-panel{min-height:630px;padding:24px 22px 18px}
  .stats-sidebar{grid-column:auto;grid-template-columns:1fr}
  .stats-sidebar section+section{padding:20px 0 0;border-left:0;border-top:1px solid var(--border-soft)}
  .shortcut-bar{width:calc(100% - 24px);gap:14px}
}

@media(max-width:560px){
  .header-nav a{font-size:13px}
  .app-shell{width:calc(100% - 18px);gap:12px}
  .practice-sidebar{display:block;padding:18px}
  .library-heading{padding:0 0 18px;border:0;border-bottom:1px solid var(--border-soft)}
  .sentence-total strong{font-size:36px}
  .overall-section{display:block}
  .mistake-button,.jump-control{width:100%;margin-top:15px}
  .practice-panel{min-height:610px;padding:21px 17px 16px}
  .practice-topline{align-items:flex-start}
  .mode-status{padding:7px 10px}
  .practice-stage{min-height:210px;padding:28px 0 20px}
  .stage-heading{align-items:flex-start;gap:10px}
  .stage-label{padding-top:7px;line-height:1.55}
  .primary-speak-button{min-width:151px;padding:8px 9px;gap:8px}
  .speak-icon{width:32px;height:32px}
  .speak-icon svg{width:20px;height:20px}
  .target-text{font-size:25px;line-height:1.5}
  .answer-line-field,.answer-lines,.answer-form textarea{min-height:126px}
  .answer-lines,.answer-form textarea{padding:14px 13px 18px;font-size:18px;line-height:1.9}
  .primary-button{min-width:0;width:100%}
  .primary-button kbd{display:none}
  .stats-sidebar{padding:19px}
  .stat-list{grid-template-columns:1fr 1fr}
  .sentence-tools{grid-template-columns:1fr}
  .sentence-tools h2{grid-column:auto}
  .shortcut-bar{width:calc(100% - 18px);justify-content:flex-start;padding:14px 17px}
  .mistake-item{grid-template-columns:32px 1fr}
  .mistake-item button{grid-column:2;justify-self:start}
  .dialog-actions{flex-direction:column-reverse}
  .dialog-actions button,.dialog-actions .primary-button{width:100%}
}

@media(prefers-reduced-motion:reduce){
  *,*::before,*::after{scroll-behavior:auto!important;transition:none!important;animation:none!important}
}