*,*::before,*::after{margin:0;padding:0;box-sizing:border-box}

    /* ===== TETSUYA'S EDUCATIONAL HTML DESIGN SYSTEM ===== */
    :root{
      /* Background & Cards */
      --bg:#F5F0E6;--bg-warm:#EDE8DE;--card:#FFFFFF;--surface:#fff;--elevated:#fff;
      /* Text Hierarchy */
      --text:#1C1917;--text-secondary:#57534E;--text-muted:#787572;
      /* Legacy aliases */
      --text2:var(--text-secondary);--text3:var(--text-muted);
      /* Borders */
      --border:rgba(28,25,23,.08);--border-visible:rgba(28,25,23,.12);
      /* Accent */
      --accent:#E85D3B;
      /* Semantic colors - Nordic muted tones */
      --blue:#0D9488;--purple:#5B7A82;--green:#4D7A56;--orange:#9A6E22;--red:#B85450;
      /* Category Colors (Difficulty Levels) */
      --cat-basic:#4D7A56;--cat-basic-light:#EDF5EF;
      --cat-comm:#C28A2E;--cat-comm-light:#FBF6ED;
      --cat-advanced:#7E5A9E;--cat-advanced-light:#F5F0F8;
      /* Conjunction Type Colors (Nordic Teal Theme) */
      --coord:#0D9488;--coord-light:#f0fdfa;
      --subord:#5B7A82;--subord-light:#f5f7f8;
      --correl:#7D8B75;--correl-light:#f6f7f5;
      --adverb:#8B8178;--adverb-light:#f8f7f6;
      /* Glass effect */
      --glass:rgba(250,248,245,.85);--blur:8px;
      /* Nordic Soft Glow Shadows */
      --shadow-sm:0 1px 2px rgba(61,67,64,.05),0 4px 12px rgba(61,67,64,.08),inset 0 1px 0 rgba(255,255,255,.5);
      --shadow:0 2px 4px rgba(61,67,64,.06),0 8px 24px rgba(61,67,64,.12),inset 0 1px 0 rgba(255,255,255,.6);
      --shadow-lg:0 4px 8px rgba(61,67,64,.06),0 16px 48px rgba(61,67,64,.15),inset 0 2px 0 rgba(255,255,255,.7);
      /* Easing and animation */
      --ease:cubic-bezier(.4,0,.2,1);--spring:cubic-bezier(.34,1.56,.64,1);
      --r:20px;--r-sm:12px;--r-full:100px;
      /* Fluid typography */
      --fs-base:clamp(15px,1.1vw,17px);--fs-qtext:clamp(17px,1.3vw,19px);
      --font:-apple-system,BlinkMacSystemFont,'SF Pro Display','SF Pro Text','Helvetica Neue','Noto Sans JP',sans-serif;
      --font-serif:'Noto Serif JP','Yu Mincho',serif;
      --anim-stagger:0.08s;
      --anim-duration:0.5s;
      --font-scale:1
    }

    /* ===== FONT SIZE SCALE ===== */
    [data-font="xs"]{--font-scale:0.85}
    [data-font="s"]{--font-scale:0.925}
    [data-font="m"]{--font-scale:1}
    [data-font="l"]{--font-scale:1.1}
    [data-font="xl"]{--font-scale:1.2}

    /* ===== DARK MODE ===== */
    [data-theme="dark"]{
      /* Background & Cards */
      --bg:#141312;--bg-warm:#1e1c1a;--card:rgba(36,34,32,.92);--card-solid:#242220;--surface:#242220;--elevated:#2C2A28;
      /* Text Hierarchy */
      --text:#F5F3F0;--text-secondary:#A3A09C;--text-muted:#8A8A8A;
      --text2:var(--text-secondary);--text3:var(--text-muted);
      /* Borders */
      --border:rgba(255,255,255,.06);--border-visible:rgba(255,255,255,.10);
      /* Accent */
      --accent:#F06A48;
      /* Semantic colors - Lighter tones for dark mode */
      --blue:#5BA8A0;--purple:#7A9AA3;--green:#6BA876;--orange:#D9A043;--red:#D4807A;
      /* Category Colors (Dark) */
      --cat-basic:#6BA876;--cat-basic-light:rgba(90,143,101,.15);
      --cat-comm:#D9A043;--cat-comm-light:rgba(194,138,46,.15);
      --cat-advanced:#9A72B8;--cat-advanced-light:rgba(126,90,158,.15);
      /* Conjunction Type Colors (Dark) */
      --coord:#5BA8A0;--coord-light:rgba(91,168,160,.12);
      --subord:#7A9AA3;--subord-light:rgba(122,154,163,.12);
      --correl:#95A58D;--correl-light:rgba(149,165,141,.12);
      --adverb:#A39B93;--adverb-light:rgba(163,155,147,.12);
      /* Glass effect */
      --glass:rgba(15,14,13,.85);
      /* Enhanced dark mode shadows */
      --shadow-sm:0 2px 8px rgba(0,0,0,.35),0 0 0 1px rgba(255,255,255,.03),inset 0 1px 0 rgba(255,255,255,.05);
      --shadow:0 4px 20px rgba(0,0,0,.5),0 0 0 1px rgba(255,255,255,.04),inset 0 1px 0 rgba(255,255,255,.06);
      --shadow-lg:0 12px 40px rgba(0,0,0,.6),0 0 0 1px rgba(255,255,255,.05),inset 0 1px 0 rgba(255,255,255,.08)
    }
    [data-theme="dark"] body{background:var(--bg);color:var(--text);background-image:radial-gradient(ellipse 100% 80% at 50% 0%,rgba(91,168,160,.06) 0%,transparent 50%),radial-gradient(ellipse 80% 60% at 20% 100%,rgba(139,129,120,.05) 0%,transparent 40%),radial-gradient(ellipse 60% 50% at 80% 80%,rgba(122,154,163,.04) 0%,transparent 40%),linear-gradient(135deg,#141312 0%,#1a1816 50%,#121110 100%);background-attachment:fixed}
    [data-theme="dark"] .intro{background:var(--bg-warm)}
    [data-theme="dark"] .ans-content{background:rgba(90,143,101,.08);border-color:rgba(90,143,101,.2);box-shadow:0 2px 8px rgba(0,0,0,.3),0 0 0 1px rgba(90,143,101,.1)}
    [data-theme="dark"] .ans-body{background:rgba(90,143,101,.04)}
    [data-theme="dark"] .q{border:1px solid var(--border-visible);box-shadow:var(--shadow-sm)}
    [data-theme="dark"] .opt{border:1px solid var(--border-visible);box-shadow:var(--shadow-sm)}
    [data-theme="dark"] .vocab-notes{background:rgba(13,148,136,.08)}
    [data-theme="dark"] .btn-primary{background:var(--text);color:var(--bg)}
    [data-theme="dark"] .btn-primary:hover{background:rgba(255,255,255,.85)}
    [data-theme="dark"] .btn-secondary{border-color:var(--border-visible);color:var(--text)}
    [data-theme="dark"] .btn-secondary:hover{background:var(--surface)}

    /* ===== BASE ===== */
    html{scroll-behavior:smooth;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
    :fullscreen,:-webkit-full-screen{scroll-behavior:auto}
    body{font:400 calc(15px * var(--font-scale))/1.6 var(--font);background:var(--bg);color:var(--text);transition:color .4s var(--ease)}

    /* ===== INTRO SECTION ===== */
    .intro{min-height:100vh;min-height:100dvh;display:flex;flex-direction:column;justify-content:center;align-items:center;text-align:center;padding:clamp(48px,10vh,100px) clamp(16px,4vw,48px);background:var(--bg-warm);position:relative}
    .intro-label{font-size:clamp(11px,1.2vw,14px);font-weight:600;letter-spacing:.15em;text-transform:uppercase;color:var(--accent);margin-bottom:clamp(16px,3vh,32px)}
    .intro-title{font-family:var(--font-serif);font-size:clamp(40px,8vw,120px);font-weight:400;line-height:1.1;letter-spacing:-.03em;margin-bottom:clamp(12px,2vh,20px);color:var(--text)}
    .intro-subtitle{font-size:clamp(14px,1.5vw,20px);color:var(--text2);max-width:min(500px,85vw);margin-bottom:clamp(24px,4vh,48px)}
    .intro-cta{display:flex;gap:clamp(12px,2vw,20px);flex-wrap:wrap;justify-content:center}
    .btn-primary{padding:clamp(12px,2vw,18px) clamp(24px,3vw,36px);background:var(--text);color:var(--bg);border:none;border-radius:100px;font:600 clamp(13px,1.1vw,16px) var(--font);cursor:pointer;transition:background .3s ease}
    .btn-primary:hover{background:rgba(0,0,0,.8)}
    .btn-secondary{padding:clamp(12px,2vw,18px) clamp(24px,3vw,36px);background:transparent;color:var(--text);border:1px solid var(--border);border-radius:100px;font:600 clamp(13px,1.1vw,16px) var(--font);cursor:pointer;transition:background .3s ease,border-color .3s ease}
    .btn-secondary:hover{background:var(--surface)}
    .intro-stats{display:flex;gap:clamp(24px,4vw,56px);margin-top:clamp(32px,6vh,72px);flex-wrap:wrap;justify-content:center}
    .intro-stat{text-align:center;min-width:80px}
    .intro-stat b{display:block;font-size:clamp(28px,4vw,44px);font-weight:700;color:var(--text);font-family:var(--font-serif)}
    .intro-stat span{font-size:clamp(9px,1vw,12px);color:var(--text3);text-transform:uppercase;letter-spacing:.1em}

    /* ===== LAYOUT - FLUID RESPONSIVE ===== */
    .wrap{
      width:clamp(320px, 94%, 1400px);
      max-width:min(90vw, 1400px);
      margin:0 auto;
      padding:clamp(32px, 6vw, 80px) clamp(12px, 3vw, 32px) clamp(60px, 10vw, 120px);
      transition:padding-top .3s var(--ease)
    }
    body.font-bar-open .wrap{padding-top:calc(clamp(32px, 6vw, 80px) + 50px)}
    body.question-bar-open .wrap{padding-top:calc(clamp(32px, 6vw, 80px) + 50px)}

    @media(min-width:1200px){
      .wrap{width:88%;max-width:1320px}
    }
    @media(min-width:1600px){
      .wrap{width:85%;max-width:1500px}
    }
    @media(min-width:1920px){
      .wrap{width:80%;max-width:1600px}
    }

    /* ===== NAVIGATION BAR ===== */
    .nav-bar{position:fixed;top:0;left:0;right:0;z-index:200;background:var(--glass);backdrop-filter:blur(6px);-webkit-backdrop-filter:blur(6px);border-bottom:1px solid var(--border);padding:clamp(6px,1.2vw,12px) clamp(12px,2vw,24px);display:flex;gap:clamp(6px,1vw,12px);flex-wrap:wrap;justify-content:center;align-items:center;transform:translateY(-100%);transition:transform .3s var(--ease);contain:layout paint}
    .nav-bar.show{transform:translateY(0)}
    :fullscreen .nav-bar,:-webkit-full-screen .nav-bar{backdrop-filter:none;-webkit-backdrop-filter:none;background:var(--bg)}
    @media(prefers-reduced-motion:reduce){.nav-bar{backdrop-filter:none;-webkit-backdrop-filter:none;background:var(--bg-primary,var(--bg))}}
    .nav-seg{display:flex;background:var(--elevated);border-radius:var(--r-sm);padding:3px;border:1px solid var(--border)}
    .nav-seg button{padding:8px 14px;border:none;background:transparent;font:500 12px var(--font);color:var(--text2);border-radius:7px;cursor:pointer;transition:background .25s var(--ease),color .25s var(--ease)}
    .nav-seg button.on{background:var(--blue);color:#fff}
    .nav-seg button:not(.on):hover{background:rgba(255,255,255,.1);color:var(--text)}
    .nav-label{padding:8px 12px;font:500 12px var(--font);color:var(--text2);opacity:0.5;letter-spacing:0.5px;user-select:none}
    .nav-btn{display:inline-flex;align-items:center;gap:5px;padding:8px 12px;border:none;border-radius:var(--r-sm);font:500 12px var(--font);cursor:pointer;transition:background .2s var(--ease),color .2s var(--ease),border-color .2s var(--ease);background:var(--elevated);color:var(--text);border:1px solid var(--border)}
    .nav-btn:hover{background:var(--surface)}
    .nav-btn:active{opacity:.8}

    /* ===== FONT SIZE SUB-BAR ===== */
    .font-subbar{display:none;width:100%;justify-content:center;align-items:center;gap:8px;padding:8px 12px;background:var(--surface);border-top:1px solid var(--border)}
    .font-subbar.show{display:flex}
    .font-subbar-label{font:500 12px var(--font);color:var(--text2)}
    .font-btn{padding:6px 12px;border:1px solid var(--border);border-radius:var(--r-sm);background:var(--elevated);font:600 11px var(--font);color:var(--text2);cursor:pointer;transition:background .2s var(--ease),border-color .2s var(--ease)}
    .font-btn:hover{background:var(--surface)}
    .font-btn.on{background:var(--blue);color:#fff;border-color:var(--blue)}

    /* ===== QUESTION SUB-BAR ===== */
    .question-subbar{display:none;width:100%;justify-content:center;align-items:center;gap:8px;padding:8px 12px;background:var(--surface);border-top:1px solid var(--border)}
    .question-subbar.show{display:flex}
    .question-btn{padding:8px 14px;border:1px solid var(--border);border-radius:var(--r-sm);background:var(--elevated);font:600 12px var(--font);color:var(--text2);cursor:pointer;transition:background .2s var(--ease),border-color .2s var(--ease)}
    .question-btn:hover{background:var(--surface)}
    .question-btn.on{background:var(--blue);color:#fff;border-color:var(--blue)}

    /* ===== VIEW SYSTEM ===== */
    .view{display:none}
    .view.active{display:block}

    /* ===== SECTION HEADER ===== */
    .sec-header{display:flex;align-items:center;gap:clamp(10px,1.5vw,18px);padding:clamp(14px,2vw,28px);margin-bottom:clamp(16px,2.5vw,24px);background:var(--surface);border-radius:var(--r);border:1px solid var(--border)}
    .sec-num{width:clamp(32px,4vw,42px);height:clamp(32px,4vw,42px);background:linear-gradient(135deg,var(--blue),var(--purple));color:#fff;border-radius:var(--r-sm);display:grid;place-items:center;font-weight:700;font-size:clamp(13px,1.2vw,16px)}
    .sec-title{font-weight:600;font-size:clamp(14px,1.2vw,17px)}
    .sec-tag{background:rgba(88,86,214,.1);color:var(--purple);padding:clamp(3px,0.5vw,5px) clamp(8px,1vw,12px);border-radius:var(--r-full);font-size:clamp(10px,0.9vw,12px);font-weight:600;margin-left:auto}

    /* ===== PASSAGE TRANSLATIONS ===== */
    .jp{display:block}
    .passage-trans-page{background:var(--surface);border-radius:var(--r);margin-bottom:16px;padding:24px;border:1px solid var(--border)}
    .passage-trans-page h2{font-size:calc(20px * var(--font-scale));font-weight:700;margin-bottom:20px;color:var(--text)}
    .passage-item{margin-bottom:24px;padding-bottom:24px;border-bottom:1px solid var(--border)}
    .passage-item:last-child{margin-bottom:0;padding-bottom:0;border-bottom:none}
    .passage-item h3{font-size:calc(16px * var(--font-scale));font-weight:600;color:var(--blue);margin-bottom:12px}
    .passage-jp{font-size:calc(14px * var(--font-scale));line-height:1.8;color:var(--text2)}
    .passage-jp p{margin-bottom:12px}

    /* ===== PASSAGE BLOCK ===== */
    .passage{background:var(--elevated);border-left:3px solid var(--blue);border-radius:0 var(--r-sm) var(--r-sm) 0;padding:clamp(14px,2.5vw,28px);margin-bottom:clamp(16px,2.5vw,24px);font-size:calc(clamp(13px,1.1vw,16px) * var(--font-scale));line-height:1.9}
    .passage p{margin-bottom:clamp(12px,1.5vw,16px);text-align:justify}
    .passage p:last-child{margin-bottom:0}
    .blank{background:rgba(255,149,0,.15);color:var(--orange);padding:2px 8px;border-radius:4px;font-weight:600}
    .ul{text-decoration:underline;text-decoration-color:var(--purple);text-underline-offset:3px}

    /* ===== VOCABULARY ===== */
    .vocab-notes{background:rgba(0,122,255,.05);border-radius:var(--r-sm);padding:14px;margin-bottom:20px;font-size:calc(13px * var(--font-scale))}
    .vocab-notes b{color:var(--blue)}
    .vocab-box{background:linear-gradient(135deg,rgba(0,122,255,.08),rgba(88,86,214,.08));border-radius:var(--r);padding:16px;margin-bottom:20px;display:none}
    .vocab-box.show{display:block}
    .vocab-title{font-weight:600;font-size:calc(14px * var(--font-scale));color:var(--purple);margin-bottom:12px;display:flex;align-items:center;gap:8px}
    .vocab-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:8px}
    .vocab-item{background:var(--surface);border-radius:var(--r-sm);padding:10px 12px;font-size:calc(12px * var(--font-scale));border:1px solid var(--border)}
    .vocab-en{font-weight:600;color:var(--text);margin-bottom:2px}
    .vocab-ja{color:var(--text2);font-size:calc(11px * var(--font-scale))}

    /* ===== QUESTION CARDS ===== */
    .q{background:var(--elevated);border-radius:var(--r);padding:clamp(14px,2.5vw,28px);margin-bottom:clamp(12px,2vw,18px);border:1px solid var(--border);contain:layout style paint}
    .q:last-child{margin-bottom:0}
    .q-num{display:inline-block;background:linear-gradient(135deg,var(--purple),var(--blue));color:#fff;padding:clamp(3px,0.5vw,5px) clamp(10px,1.5vw,16px);border-radius:var(--r-full);font-weight:600;font-size:clamp(11px,1vw,13px);margin-bottom:clamp(10px,1.5vw,16px)}
    .q-text{font-size:calc(clamp(13px,1.2vw,16px) * var(--font-scale));line-height:1.7;margin-bottom:clamp(12px,1.5vw,16px)}
    .q-text b{color:var(--purple)}

    /* ===== OPTIONS (Grid Layout for Equal-Width Cards) ===== */
    .opts{display:grid;grid-template-columns:repeat(4,1fr);gap:clamp(6px,1vw,12px);margin-bottom:clamp(12px,1.5vw,16px)}
    .opts.vertical{grid-template-columns:1fr}
    .opt{background:var(--surface);border:1px solid rgba(0,0,0,.15);border-radius:var(--r-sm);padding:clamp(10px,1.2vw,14px) clamp(12px,1.5vw,18px);font-size:calc(clamp(12px,1vw,14px) * var(--font-scale));line-height:1.5;box-shadow:0 1px 3px rgba(0,0,0,.05);contain:layout style paint;display:flex;align-items:center;cursor:pointer}
    .opt-label{color:var(--blue);font-weight:600;margin-right:clamp(6px,0.8vw,10px)}

    /* ===== TRANSLATION QUESTIONS ===== */
    .translation-q{background:var(--elevated);border-radius:var(--r);padding:20px;margin-bottom:14px;border-left:3px solid var(--purple)}
    .translation-q .q-num{background:linear-gradient(135deg,var(--purple),var(--accent))}

    /* ===== BUTTONS ===== */
    .q-btns{display:flex;gap:8px}
    .hint-btn,.ans-btn{padding:10px 16px;border:none;border-radius:var(--r-full);font:500 13px var(--font);cursor:pointer;transition:background .2s var(--ease)}
    .hint-btn:active,.ans-btn:active{opacity:.8}
    .hint-btn{background:rgba(255,149,0,.1);color:var(--orange);border:1px solid rgba(255,149,0,.2)}
    .ans-btn{background:var(--green);color:#fff;transition:background .2s var(--ease)}
    .ans-btn:hover{background:#4A7A55}

    /* ===== EXPAND/COLLAPSE ALL BUTTONS ===== */
    .bulk-actions{display:flex;gap:8px;margin-bottom:16px;padding:0 4px}
    .expand-all-btn,.collapse-all-btn{padding:8px 14px;border:1px solid var(--border-visible);border-radius:var(--r-sm);background:var(--elevated);font:500 12px var(--font);color:var(--text2);cursor:pointer;transition:background .2s var(--ease),border-color .2s var(--ease)}
    .expand-all-btn:hover,.collapse-all-btn:hover{background:var(--surface);border-color:var(--blue)}
    .expand-all-btn:active,.collapse-all-btn:active{opacity:.8}

    /* ===== COLLAPSIBLE BOXES (No Animation - GPU Safe) ===== */
    .hint-box,.ans-box{display:none;margin-top:14px}
    .hint-box.show,.ans-box.show{display:block}

    /* ===== ANSWER CONTENT ===== */
    .hint-content{background:rgba(255,149,0,.08);border:1px solid rgba(255,149,0,.15);border-radius:var(--r-sm);padding:14px;font-size:calc(13px * var(--font-scale))}
    .hint-content b{color:var(--orange)}
    .ans-content{background:#FBFDFB;border:1px solid rgba(90,143,101,.18);border-radius:var(--r-sm);padding:0;font-size:calc(13px * var(--font-scale));line-height:1.75;overflow:hidden;box-shadow:0 1px 2px rgba(74,122,85,.04),0 4px 12px rgba(74,122,85,.08),0 0 0 1px rgba(90,143,101,.05)}
    .ans-header{background:linear-gradient(135deg,#5A8F65 0%,#4A7A55 100%);color:#fff;padding:12px 16px;font-weight:600;font-size:calc(13px * var(--font-scale))}
    .ans-body{padding:16px;background:#F7FAF8}
    .ans-section{margin-bottom:16px;padding-bottom:16px;border-bottom:1px solid var(--border)}
    .ans-section:last-child{margin-bottom:0;padding-bottom:0;border-bottom:none}
    .ans-section-title{font-size:calc(12px * var(--font-scale));font-weight:600;color:var(--text2);margin-bottom:8px;display:flex;align-items:center;gap:6px}
    .correct{color:var(--green);font-weight:700;font-size:calc(18px * var(--font-scale));margin-bottom:4px}
    .jp{color:var(--text2);font-size:calc(12px * var(--font-scale));margin-top:4px;padding-left:12px;border-left:2px solid var(--border)}
    .ans-steps{margin:0;padding-left:0;list-style:none}
    .ans-steps li{padding:8px 12px;background:rgba(0,122,255,.05);border-radius:var(--r-sm);margin-bottom:6px;font-size:calc(13px * var(--font-scale))}
    .ans-steps li:last-child{margin-bottom:0}
    .ans-choices{display:grid;grid-template-columns:repeat(2,1fr);gap:8px;font-size:calc(13px * var(--font-scale))}
    @media(max-width:500px){.ans-choices{grid-template-columns:1fr}}
    .ans-choice{padding:10px 12px;background:var(--elevated);border-radius:var(--r-sm);border:1px solid var(--border);display:flex;gap:8px;align-items:baseline}
    .ans-choice-label{font-weight:700;color:var(--blue);min-width:20px}
    .ans-wrong{margin-top:12px}
    .ans-wrong-item{padding:8px 12px;background:rgba(255,59,48,.05);border-radius:var(--r-sm);margin-bottom:6px;font-size:calc(12px * var(--font-scale))}
    .ans-wrong-item:last-child{margin-bottom:0}
    .ans-wrong-item b{color:var(--red)}
    .wrong-ok{color:var(--green)}
    .wrong-no{color:var(--red)}
    /* Colorblind-safe indicators */
    .wrong-ok::before{content:"O";display:inline-flex;justify-content:center;align-items:center;width:18px;height:18px;border-radius:50%;background:var(--green);color:#fff;font-size:10px;font-weight:700;margin-right:6px}
    .wrong-no::before{content:"X";display:inline-flex;justify-content:center;align-items:center;width:18px;height:18px;border-radius:50%;background:var(--red);color:#fff;font-size:10px;font-weight:700;margin-right:6px}
    .tip{background:rgba(255,149,0,.1);border-left:3px solid var(--orange);padding:10px 12px;border-radius:0 var(--r-sm) var(--r-sm) 0;margin-top:12px;font-size:calc(12px * var(--font-scale))}
    .tip b{color:var(--orange)}

    /* ===== THREE-LAYER DEEP ANALYSIS SYSTEM ===== */
    .ans-meta{display:flex;gap:16px;align-items:center;padding:10px 14px;background:linear-gradient(135deg,rgba(13,148,136,.08),rgba(91,122,130,.08));border-radius:var(--r-sm);margin-bottom:14px;font-size:calc(13px * var(--font-scale));flex-wrap:wrap}
    .ans-meta-item{display:flex;align-items:center;gap:6px;color:var(--text2)}
    .ans-meta-item b{color:var(--text)}
    .difficulty{display:flex;gap:2px}
    .difficulty .star{color:var(--orange)}
    .difficulty .star-empty{color:var(--border-visible)}

    /* Layer toggle buttons */
    .layer-toggles{display:flex;gap:8px;margin:14px 0;flex-wrap:wrap}
    .layer-toggle{display:flex;align-items:center;gap:6px;padding:8px 14px;border:1px solid var(--border-visible);border-radius:var(--r-sm);background:var(--elevated);font:500 12px var(--font);color:var(--text2);cursor:pointer;transition:all .2s var(--ease)}
    .layer-toggle:hover{background:var(--surface);border-color:var(--blue)}
    .layer-toggle.active{background:var(--blue);color:#fff;border-color:var(--blue)}
    .layer-toggle .layer-icon{font-size:14px}

    /* Layer content boxes */
    .layer-box{display:none;margin:12px 0;padding:14px;border-radius:var(--r-sm);font-size:calc(13px * var(--font-scale));line-height:1.75}
    .layer-box.show{display:block}
    .layer-box h4{font-size:calc(14px * var(--font-scale));font-weight:600;margin-bottom:10px;display:flex;align-items:center;gap:8px}

    /* Layer 1: 行間を読む */
    .layer-1{background:rgba(13,148,136,.06);border-left:3px solid var(--blue)}
    .layer-1 h4{color:var(--blue)}
    .layer-1 .layer-item{padding:8px 0;border-bottom:1px dashed rgba(13,148,136,.2)}
    .layer-1 .layer-item:last-child{border-bottom:none}
    .layer-1 .layer-label{font-weight:600;color:var(--blue);margin-bottom:4px}

    /* Layer 2: 筆者の意図 */
    .layer-2{background:rgba(126,90,158,.06);border-left:3px solid var(--purple)}
    .layer-2 h4{color:var(--purple)}
    .layer-2 .layer-item{padding:8px 0;border-bottom:1px dashed rgba(126,90,158,.2)}
    .layer-2 .layer-item:last-child{border-bottom:none}
    .layer-2 .layer-label{font-weight:600;color:var(--purple);margin-bottom:4px}

    /* Layer 3: 問題作成者の意図 */
    .layer-3{background:rgba(184,84,80,.06);border-left:3px solid var(--red)}
    .layer-3 h4{color:var(--red)}
    .layer-3 .layer-item{padding:8px 0;border-bottom:1px dashed rgba(184,84,80,.2)}
    .layer-3 .layer-item:last-child{border-bottom:none}
    .layer-3 .layer-label{font-weight:600;color:var(--red);margin-bottom:4px}

    /* Trap type badges */
    .trap-badge{display:inline-flex;align-items:center;gap:4px;padding:2px 8px;border-radius:var(--r-full);font-size:calc(10px * var(--font-scale));font-weight:600;margin-right:6px}
    .trap-opposite{background:rgba(184,84,80,.15);color:var(--red)}
    .trap-partial{background:rgba(154,110,34,.15);color:var(--orange)}
    .trap-notmentioned{background:rgba(91,122,130,.15);color:var(--purple)}
    .trap-overgeneralization{background:rgba(77,122,86,.15);color:var(--green)}
    .trap-truewrong{background:rgba(13,148,136,.15);color:var(--blue)}
    .trap-misplaced{background:rgba(139,129,120,.15);color:var(--text2)}
    .trap-extreme{background:rgba(184,84,80,.15);color:var(--red)}

    /* Dark mode adjustments for layers */
    [data-theme="dark"] .layer-1{background:rgba(91,168,160,.1)}
    [data-theme="dark"] .layer-2{background:rgba(154,114,184,.1)}
    [data-theme="dark"] .layer-3{background:rgba(212,128,122,.1)}
    [data-theme="dark"] .ans-meta{background:rgba(91,168,160,.08)}

    /* ===== REVIEW TABS ===== */
    .review-tabs{display:flex;gap:0;margin-bottom:16px;border-bottom:2px solid var(--border)}
    .review-tab{padding:10px 20px;border:none;background:transparent;font:600 calc(13px * var(--font-scale)) var(--font);color:var(--text2);cursor:pointer;border-bottom:2px solid transparent;margin-bottom:-2px;transition:all .2s var(--ease)}
    .review-tab:hover{color:var(--text);background:var(--surface)}
    .review-tab.active{color:var(--blue);border-bottom-color:var(--blue)}
    .review-content{display:none}
    .review-content.show{display:block}
    .quick-tip{padding:14px;background:linear-gradient(135deg,rgba(13,148,136,.08),rgba(91,122,130,.08));border-radius:var(--r-sm);font-size:calc(14px * var(--font-scale));line-height:1.75}
    .explanation-narrative{margin:16px 0;padding:16px;background:var(--surface);border-radius:var(--r-sm);border-left:3px solid var(--blue)}
    .narrative-text{font-size:calc(14px * var(--font-scale));line-height:1.9;color:var(--text)}
    .narrative-text p{margin-bottom:1em;text-indent:1em}
    .narrative-text p:last-child{margin-bottom:0}
    [data-theme="dark"] .explanation-narrative{background:rgba(91,168,160,.06)}

    /* ===== TRANSLATION REVEAL SYSTEM ===== */
    .hidden-until-reveal{display:none}
    .q.revealed .hidden-until-reveal{display:block}
    .q-text-jp{font-size:calc(13px * var(--font-scale));color:var(--text2);margin-top:8px;padding:10px 12px;background:rgba(109,129,150,.06);border-left:2px solid var(--blue);border-radius:0 var(--r-sm) var(--r-sm) 0;line-height:1.75}

    /* Option translation */
    .opt-jp{font-size:calc(12px * var(--font-scale));color:var(--text2);line-height:1.6}

    /* SHORT CHOICES: horizontal layout */
    .opts:not(.vertical) .opt-jp{margin-left:auto;margin-top:0;padding-left:12px;width:auto;white-space:nowrap}

    /* LONG CHOICES: stacked layout */
    .opts.vertical .opt{flex-wrap:wrap;align-items:flex-start}
    .opts.vertical .opt-jp{flex-basis:100%;margin-top:6px;margin-left:0;padding-left:28px}

    /* Correct answer highlight */
    .q.revealed .opt.correct-opt{
      border-left:4px solid var(--blue);
      background:rgba(13,148,136,.06);
      box-shadow:0 0 0 1px rgba(13,148,136,.15),0 4px 12px rgba(13,148,136,.12),0 8px 24px rgba(13,148,136,.08);
      transform:translateY(-1px)
    }
    [data-theme="dark"] .q.revealed .opt.correct-opt{
      background:rgba(45,212,191,.08);
      box-shadow:0 0 0 1px rgba(45,212,191,.2),0 4px 16px rgba(45,212,191,.15),0 8px 32px rgba(45,212,191,.1)
    }

    .correct-compact{display:flex;align-items:center;gap:8px;padding:8px 12px;background:rgba(90,143,101,.08);border-radius:var(--r-sm);border:1px solid rgba(90,143,101,.15)}
    .correct-num{font-size:calc(24px * var(--font-scale));font-weight:700;color:var(--green);min-width:28px}
    [data-theme="dark"] .q-text-jp{background:rgba(109,129,150,.12)}
    [data-theme="dark"] .correct-compact{background:rgba(90,143,101,.15);border-color:rgba(90,143,101,.25)}

    /* ===== TRUE/FALSE QUESTION ===== */
    .tf-item{background:var(--surface);border:1px solid var(--border);border-radius:var(--r-sm);padding:14px;margin-bottom:10px;font-size:calc(14px * var(--font-scale));line-height:1.6;contain:layout style paint}
    .tf-item:last-child{margin-bottom:14px}
    .tf-num{display:inline-block;background:var(--blue);color:#fff;width:24px;height:24px;border-radius:50%;text-align:center;line-height:24px;font-size:calc(12px * var(--font-scale));font-weight:600;margin-right:10px}
    .tf-answer{display:none}

    /* ===== T/F EXPLANATIONS ===== */
    .tf-explanations{margin-top:16px}
    .tf-explain{background:var(--surface);border:1px solid var(--border);border-radius:var(--r-sm);padding:16px;margin-bottom:12px}
    .tf-explain:last-child{margin-bottom:0}
    .tf-explain-header{font-size:calc(15px * var(--font-scale));font-weight:700;margin-bottom:10px;padding-bottom:8px;border-bottom:1px solid var(--border)}
    .tf-explain-stmt{font-size:calc(13px * var(--font-scale));line-height:1.7;margin-bottom:6px;color:var(--text)}
    .tf-explain-stmt-jp{font-size:calc(13px * var(--font-scale));line-height:1.7;margin-bottom:10px;color:var(--text2)}
    .tf-explain-quote{font-size:calc(12px * var(--font-scale));line-height:1.7;padding:10px 12px;background:rgba(0,122,255,.04);border-left:3px solid var(--blue);border-radius:0 var(--r-sm) var(--r-sm) 0;margin-bottom:10px}
    .tf-explain-quote b{color:var(--blue)}
    .tf-explain-reason{font-size:calc(13px * var(--font-scale));line-height:1.8;padding:10px 12px;background:var(--bg-warm);border-radius:var(--r-sm)}
    .tf-explain-reason b{color:var(--text)}

    /* ===== FAB (Scroll to Top) ===== */
    .fab{position:fixed;bottom:24px;right:24px;width:48px;height:48px;background:var(--blue);color:#fff;border:none;border-radius:50%;font-size:20px;cursor:pointer;box-shadow:0 4px 12px rgba(0,122,255,.3);opacity:0;visibility:hidden;transition:opacity .3s var(--ease),visibility .3s var(--ease);z-index:1000}
    .fab.show{opacity:1;visibility:visible}
    .fab:active{opacity:.8}

    /* Skip Link for Keyboard Navigation */
    .skip-link{position:absolute;top:-100%;left:16px;padding:12px 20px;background:var(--blue);color:#fff;border-radius:var(--r-sm);font:600 13px var(--font);text-decoration:none;z-index:1000;transition:top .2s var(--ease)}
    .skip-link:focus{top:16px}

    /* ===== FOOTER ===== */
    footer{text-align:center;padding:40px 20px;color:var(--text3);font-size:12px}

    /* ===== RESPONSIVE ===== */
    @media(min-width:1400px){
      .intro{padding:100px 48px}
      .intro-title{font-size:clamp(72px,8vw,120px)}
      .intro-stats{gap:56px}
      .intro-stat b{font-size:44px}
      .sec-header{padding:24px 28px}
      .q{padding:28px}
      .opts{gap:12px}
      .passage{padding:28px;font-size:calc(15px * var(--font-scale))}
      .ans-body{padding:20px}
    }

    @media(min-width:1200px) and (max-width:1399px){
      .intro{padding:90px 40px}
      .intro-title{font-size:clamp(64px,7vw,100px)}
      .intro-stats{gap:48px}
      .sec-header{padding:22px 24px}
      .q{padding:24px}
      .passage{padding:24px}
    }

    @media(min-width:1024px) and (max-width:1199px){
      .intro{padding:80px 32px}
      .intro-title{font-size:clamp(56px,8vw,88px)}
      .intro-stats{gap:40px}
      .sec-header{padding:20px 22px}
      .q{padding:22px}
    }

    @media(min-width:769px) and (max-width:1023px){
      .intro{padding:70px 28px}
      .intro-title{font-size:clamp(48px,9vw,72px)}
      .intro-stats{gap:36px}
      .sec-header{padding:18px 20px}
      .q{padding:20px}
      .opts{grid-template-columns:repeat(2,1fr);gap:10px}
    }

    @media(min-width:601px) and (max-width:768px){
      .intro{padding:60px 20px}
      .intro-title{font-size:clamp(40px,10vw,64px)}
      .intro-subtitle{font-size:16px}
      .intro-stats{gap:28px;flex-wrap:wrap}
      .intro-stat b{font-size:32px}
      .sec-header{padding:16px 18px;flex-wrap:wrap;gap:10px}
      .sec-tag{margin-left:0;margin-top:4px}
      .q{padding:18px}
      .opts{grid-template-columns:repeat(2,1fr);gap:8px}
      .passage{padding:18px;font-size:calc(14px * var(--font-scale))}
      .nav-bar{padding:8px 12px}
      .nav-seg button{padding:6px 12px;font-size:11px}
    }

    @media(min-width:481px) and (max-width:600px){
      .intro{padding:50px 16px}
      .intro-title{font-size:clamp(36px,11vw,52px)}
      .intro-subtitle{font-size:15px;max-width:90%}
      .intro-stats{gap:20px;flex-wrap:wrap}
      .intro-stat b{font-size:28px}
      .intro-cta{flex-direction:column;width:100%;max-width:280px}
      .btn-primary,.btn-secondary{width:100%;text-align:center}
      .sec-header{padding:14px 16px;flex-direction:column;align-items:flex-start;gap:8px}
      .sec-tag{margin-left:0}
      .q{padding:16px}
      .opts{grid-template-columns:1fr;gap:8px}
      .passage{padding:16px;font-size:calc(13px * var(--font-scale));line-height:1.8}
      .nav-bar{padding:8px 10px;gap:6px}
      .nav-seg{width:100%;justify-content:center}
      .nav-seg button{flex:1;padding:8px 10px;font-size:11px}
      .nav-btn{padding:6px 10px;font-size:11px}
    }

    @media(min-width:376px) and (max-width:480px){
      .intro{padding:40px 14px}
      .intro-title{font-size:clamp(32px,12vw,44px)}
      .intro-subtitle{font-size:14px;max-width:95%}
      .intro-stats{gap:16px;flex-wrap:wrap;justify-content:center}
      .intro-stat{min-width:80px}
      .intro-stat b{font-size:24px}
      .intro-stat span{font-size:10px}
      .intro-cta{flex-direction:column;width:100%;padding:0 8px}
      .btn-primary,.btn-secondary{width:100%;padding:14px 24px}
      .sec-header{padding:12px 14px;flex-direction:column;align-items:flex-start;gap:6px}
      .sec-num{width:32px;height:32px;font-size:13px}
      .sec-title{font-size:14px}
      .sec-tag{margin-left:0;font-size:10px;padding:3px 8px}
      .q{padding:14px;margin-bottom:12px}
      .q-num{padding:3px 12px;font-size:11px}
      .q-text{font-size:calc(14px * var(--font-scale))}
      .opts{grid-template-columns:1fr;gap:6px}
      .opt{padding:10px 12px;font-size:calc(12px * var(--font-scale))}
      .passage{padding:14px;font-size:calc(13px * var(--font-scale));line-height:1.75}
      .ans-body{padding:12px}
      .ans-choices{grid-template-columns:1fr}
      .nav-bar{padding:6px 8px;gap:4px}
      .nav-seg{width:100%}
      .nav-seg button{flex:1;padding:7px 8px;font-size:10px}
      .nav-btn{padding:6px 8px;font-size:10px}
      .nav-label{padding:6px 8px;font-size:10px}
      .fab{width:44px;height:44px;font-size:18px;bottom:16px;right:16px}
    }

    @media(max-width:375px){
      .intro{padding:32px 12px}
      .intro-label{font-size:11px;letter-spacing:.1em;margin-bottom:16px}
      .intro-title{font-size:clamp(28px,13vw,38px)}
      .intro-subtitle{font-size:13px;margin-bottom:24px}
      .intro-stats{gap:12px;flex-wrap:wrap;justify-content:center}
      .intro-stat{min-width:70px}
      .intro-stat b{font-size:22px}
      .intro-stat span{font-size:9px}
      .intro-cta{flex-direction:column;width:100%;gap:10px}
      .btn-primary,.btn-secondary{width:100%;padding:12px 20px;font-size:14px}
      .sec-header{padding:10px 12px;flex-direction:column;align-items:flex-start;gap:6px}
      .sec-num{width:28px;height:28px;font-size:12px}
      .sec-title{font-size:13px}
      .sec-tag{font-size:9px;padding:2px 6px}
      .q{padding:12px;margin-bottom:10px}
      .q-num{padding:3px 10px;font-size:10px;margin-bottom:10px}
      .q-text{font-size:calc(13px * var(--font-scale));line-height:1.6;margin-bottom:10px}
      .opts{grid-template-columns:1fr;gap:5px}
      .opt{padding:9px 10px;font-size:calc(11px * var(--font-scale))}
      .opt-label{font-size:11px;margin-right:6px}
      .passage{padding:12px;font-size:calc(12px * var(--font-scale));line-height:1.7}
      .vocab-grid{grid-template-columns:1fr}
      .vocab-item{padding:8px 10px}
      .vocab-en{font-size:calc(11px * var(--font-scale))}
      .vocab-ja{font-size:calc(10px * var(--font-scale))}
      .ans-btn,.hint-btn{padding:8px 12px;font-size:12px}
      .q-btns{flex-wrap:wrap}
      .ans-body{padding:10px}
      .ans-section{padding-bottom:12px;margin-bottom:12px}
      .ans-choices{grid-template-columns:1fr;gap:6px}
      .ans-choice{padding:8px 10px;font-size:calc(12px * var(--font-scale))}
      .ans-wrong-item{padding:6px 10px;font-size:calc(11px * var(--font-scale))}
      .tip{padding:8px 10px;font-size:calc(11px * var(--font-scale))}
      .correct{font-size:calc(16px * var(--font-scale))}
      .jp{font-size:calc(11px * var(--font-scale))}
      .nav-bar{padding:5px 6px;gap:3px}
      .nav-seg{width:100%}
      .nav-seg button{flex:1;padding:6px 6px;font-size:9px}
      .nav-btn{padding:5px 7px;font-size:9px}
      .nav-label{display:none}
      .fab{width:40px;height:40px;font-size:16px;bottom:12px;right:12px}
      footer{padding:24px 12px;font-size:11px}
    }

    @media(max-height:500px) and (orientation:landscape){
      .intro{min-height:auto;padding:40px 24px}
      .intro-title{font-size:clamp(32px,8vw,48px)}
      .intro-stats{margin-top:24px}
      .nav-bar{position:sticky}
    }

    @media(hover:hover) and (pointer:fine){
      /* Simplified transitions - removed transform to reduce GPU load on 140+ elements */
      .opt{transition:opacity .2s var(--ease)}
      .opt:hover{opacity:0.85}
      .q{transition:box-shadow .2s var(--ease)}
      .q:hover{box-shadow:var(--shadow)}
    }

    @media(hover:none) and (pointer:coarse){
      .opt{-webkit-tap-highlight-color:transparent}
      .opt:active{background:var(--bg-warm);border-color:var(--blue)}
      .ans-btn:active,.hint-btn:active{transform:scale(0.98)}
    }

    /* ===== PREMIUM ENHANCEMENTS ===== */
    /* Simplified gradient - reduced from 3 to 1 radial gradient for GPU efficiency */
    body::before{
      content:'';
      position:fixed;
      inset:0;
      pointer-events:none;
      z-index:-1;
      background:radial-gradient(ellipse 100% 80% at 50% 0%, rgba(109,129,150,.04) 0%, transparent 60%),var(--bg)
    }
    [data-theme="dark"] body::before{
      background:radial-gradient(ellipse 100% 80% at 50% 0%, rgba(109,129,150,.06) 0%, transparent 60%),var(--bg)
    }

    /* backdrop-filter and contain now set in main .nav-bar rule above */

    /* Consolidated animations - reduced stagger count, uses opacity-only for GPU efficiency */
    .view.active .sec-header,
    .view.active .passage,
    .view.active .vocab-notes,
    .view.active .passage-trans-page,
    .view.active .passage-item{
      animation:fadeIn 0.3s var(--ease) backwards
    }
    .view.active .sec-header{animation-delay:0.05s}
    .view.active .passage,
    .view.active .passage-trans-page{animation-delay:0.1s}
    .view.active .vocab-notes,
    .view.active .passage-item{animation-delay:0.15s}

    @keyframes fadeIn{
      from{opacity:0}
      to{opacity:1}
    }
    @keyframes fadeInUp{
      from{opacity:0;transform:translateY(16px)}
      to{opacity:1;transform:translateY(0)}
    }

    .intro .intro-label,
    .intro .intro-title,
    .intro .intro-subtitle,
    .intro .intro-cta,
    .intro .intro-stats{
      animation:fadeInUp var(--anim-duration) var(--ease) backwards
    }
    .intro .intro-label{animation-delay:0.1s}
    .intro .intro-title{animation-delay:0.2s}
    .intro .intro-subtitle{animation-delay:0.3s}
    .intro .intro-cta{animation-delay:0.4s}
    .intro .intro-stats{animation-delay:0.5s}

    .view{
      opacity:0;
      transition:opacity 0.25s var(--ease)
    }
    .view.active{
      opacity:1
    }

    .btn-primary:hover{background:rgba(0,0,0,.8)}
    .btn-primary:active{opacity:.8}
    .btn-secondary:hover{background:var(--surface)}
    .btn-secondary:active{opacity:.8}

    .ans-btn{transition:background .2s var(--ease)}
    .ans-btn:hover{background:rgba(52,199,89,.85)}
    .ans-btn:active{opacity:.8}
    .hint-btn{transition:background .2s var(--ease)}
    .hint-btn:hover{background:rgba(255,149,0,.2)}
    .hint-btn:active{opacity:.8}

    .nav-seg button{transition:background .25s var(--ease),color .25s var(--ease)}
    .nav-btn{transition:background .2s var(--ease),color .2s var(--ease),border-color .2s var(--ease)}
    .nav-btn:hover{background:rgba(0,0,0,.03)}

    .fab{opacity:0;visibility:hidden;transition:opacity .3s var(--ease),visibility .3s var(--ease)}
    .fab.show{opacity:1;visibility:visible}
    .fab:hover{opacity:.9;box-shadow:0 8px 28px rgba(109,129,150,.5)}
    .fab:active{opacity:0.8}

    /* GPU-safe expand/collapse - uses display toggle instead of max-height animation */
    .vocab-box{
      display:none;
      opacity:0;
      padding:16px;
      margin-bottom:20px;
      transition:opacity 0.25s var(--ease)
    }
    .vocab-box.show{
      display:block;
      opacity:1
    }

    .intro-title{
      font-family:var(--font-serif);
      font-weight:500;
      letter-spacing:-0.02em
    }
    .intro-stat b{
      font-family:var(--font-serif);
      font-weight:600
    }
    .sec-title{
      font-family:var(--font);
      font-weight:600;
      letter-spacing:0.01em
    }
    .passage-item h3{
      font-family:var(--font-serif);
      font-weight:500
    }
    .correct{
      font-family:var(--font);
      font-weight:700
    }

    .passage-jp,
    .jp,
    .ans-body{
      line-height:1.85
    }

    .opt{
      transition:border-color 0.2s var(--ease),background 0.2s var(--ease)
    }
    .opt:focus-visible{
      border-color:var(--blue);
      background:rgba(109,129,150,.06);
      outline:2px solid var(--blue);
      outline-offset:2px
    }

    @media(prefers-reduced-motion:reduce){
      *,*::before,*::after{
        animation-duration:0.01ms !important;
        animation-iteration-count:1 !important;
        transition-duration:0.01ms !important
      }
      .view{transition:none}
      .hint-box,.ans-box,.vocab-box{transition:none}
      .nav-bar{backdrop-filter:none;-webkit-backdrop-filter:none;background:var(--bg)}
      body::before{display:none}
    }

    .sec-header{
      box-shadow:0 2px 12px rgba(0,0,0,.04)
    }
    [data-theme="dark"] .sec-header{
      box-shadow:0 2px 12px rgba(0,0,0,.2)
    }

    .ans-content{
      box-shadow:0 2px 16px rgba(52,199,89,.08)
    }
    .ans-header{
      letter-spacing:0.02em
    }

    .q{
      box-shadow:0 1px 4px rgba(0,0,0,.03)
    }
    .translation-q{
      box-shadow:0 1px 4px rgba(0,0,0,.03)
    }
    [data-theme="dark"] .q,
    [data-theme="dark"] .translation-q{
      box-shadow:none
    }

    /* ===== SPLIT VIEW MODE ===== */
    :root{
      --split-left-width:50%;
      --split-min-width:20%
    }

    body.split-active .view.active{display:none}
    body.split-active .split-container{display:flex}

    .split-container{
      display:none;
      position:fixed;
      top:0;
      left:0;
      right:0;
      bottom:0;
      z-index:10;
      background:var(--bg)
    }

    .split-left{
      width:var(--split-left-width,50%);
      min-width:var(--split-min-width);
      overflow-y:auto;
      padding:clamp(12px,2vw,24px);
      background:var(--bg);
      contain:layout style paint
    }

    .split-right{
      flex:1;
      min-width:var(--split-min-width);
      overflow-y:auto;
      padding:clamp(12px,2vw,24px);
      background:var(--bg);
      contain:layout style paint
    }

    .split-resizer{
      width:8px;
      background:var(--border-visible);
      cursor:col-resize;
      flex-shrink:0;
      transition:background 0.15s ease
    }

    .split-resizer:hover,
    .split-resizer.dragging{
      background:var(--blue)
    }

    .split-content{
      max-width:none
    }

    .split-content .passage{
      margin-bottom:20px
    }

    .split-content .q{
      margin-bottom:16px
    }

    .split-left .sec-header{
      padding:12px 16px;
      margin-bottom:12px;
      margin-top:40px
    }

    .split-right .bulk-actions{
      padding:10px 0;
      margin-bottom:12px;
      margin-top:40px
    }

    body.question-bar-open .split-left .sec-header{
      margin-top:90px
    }

    body.question-bar-open .split-right .bulk-actions{
      margin-top:90px
    }

    #split-toggle{
      min-width:60px;
      text-align:center
    }

    #split-toggle[aria-pressed="true"]{
      background:var(--blue);
      color:#fff
    }

    @media(max-width:767px){
      #split-toggle{display:none}
    }

    @media(prefers-reduced-motion:reduce){
      .split-resizer{transition:none}
    }

    /* ===== POSTER BLOCK ===== */
    .poster-block{background:var(--elevated);border:2px solid var(--border-visible);border-radius:var(--r);padding:clamp(16px,3vw,32px);margin-bottom:clamp(16px,2.5vw,24px);font-size:calc(clamp(13px,1.1vw,15px) * var(--font-scale));line-height:1.7}
    .poster-block h4{font-size:calc(18px * var(--font-scale));font-weight:700;text-align:center;margin-bottom:16px;color:var(--text)}
    .poster-block p{margin-bottom:12px}
    .poster-block .company-name{font-weight:700;font-size:calc(16px * var(--font-scale));color:var(--blue);text-align:center;margin:16px 0 8px}
    .poster-block .tagline{font-style:italic;text-align:center;margin-bottom:16px}
    .poster-block .address{font-size:calc(12px * var(--font-scale));color:var(--text2);margin-top:16px}