/* ── Reset & tokens ── */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{
  --ink:#1a1a1a; --soft:#5a5a6a; --rule:#dddbe0; --page:#f7f6f3;
  --white:#ffffff; --accent:#1A3F7A; --accent-l:#EAF0FA;
  --pass:#1A6B30; --pass-l:#EAF5EC; --fail:#8A1A1A; --fail-l:#FAF0EF;
  --warn:#7A5C10; --warn-l:#FFF8E0;
  --v1:#C05A1A; --v1l:#FFF3E8; --v1m:#F0A06A;
  --v2:#0F6B7A; --v2l:#E8F6F8; --v2m:#6AC4D0;
  --v3:#1A6B30; --v3l:#EAF5EC; --v3m:#6AC88A;
  --v4:#5C2A8A; --v4l:#F3EDF9; --v4m:#B08AD0;
  --v5:#1A3F7A; --v5l:#EAF0FA; --v5m:#7090CC;
  --c:#1A3F7A; --cl:#EAF0FA; --cm:#7090CC; /* active version */
  --r:6px;
}
body{font-family:'DM Sans',sans-serif;background:var(--page);color:var(--ink);min-height:100vh;padding-bottom:64px}

/* ── Top bar ── */
.topbar{
  background:var(--ink);color:#fff;
  display:flex;align-items:center;justify-content:space-between;
  padding:14px 28px;position:sticky;top:0;z-index:100;
  box-shadow:0 2px 12px rgba(0,0,0,.25)
}
.topbar-brand{display:flex;align-items:center;gap:10px}
.topbar-brand .logo{font-family:'DM Serif Display',serif;font-size:1rem;opacity:.9}
.topbar-brand .sub{font-size:.72rem;opacity:.55;letter-spacing:.04em}
.topbar-right{display:flex;align-items:center;gap:12px}
.key-btn{
  background:rgba(255,255,255,.1);border:1px solid rgba(255,255,255,.2);
  color:#fff;border-radius:4px;padding:6px 14px;font-size:.75rem;
  letter-spacing:.05em;text-transform:uppercase;cursor:pointer;
  font-family:'DM Sans',sans-serif;transition:.15s
}
.key-btn:hover{background:rgba(255,255,255,.18)}
.key-btn.on{background:var(--pass);border-color:var(--pass)}

/* ── Version selector ── */
.version-bar{
  display:flex;gap:0;padding:0 28px;background:var(--ink);
  border-top:1px solid rgba(255,255,255,.08)
}
.vbtn{
  padding:10px 18px;font-size:.78rem;font-weight:500;letter-spacing:.04em;
  color:rgba(255,255,255,.45);border:none;background:none;cursor:pointer;
  border-bottom:2.5px solid transparent;transition:.15s;
  font-family:'DM Sans',sans-serif;display:flex;align-items:center;gap:6px;
  white-space:nowrap
}
.vbtn:hover{color:rgba(255,255,255,.75)}
.vbtn.active{color:#fff;border-bottom-color:var(--cm)}

/* ── Main layout ── */
.shell{max-width:860px;margin:0 auto;padding:28px 20px}

/* ── Exam header ── */
.exam-header{
  background:var(--cl);border:1.5px solid var(--cm);border-radius:var(--r);
  padding:22px 26px;margin-bottom:24px;display:flex;align-items:center;gap:20px
}
.exam-icon{font-size:2.2rem}
.exam-info h1{font-family:'DM Serif Display',serif;font-size:1.55rem;color:var(--c)}
.exam-info p{font-size:.82rem;color:var(--soft);margin-top:3px;line-height:1.5}
.exam-badge{
  margin-left:auto;text-align:center;flex-shrink:0;
  background:var(--c);color:#fff;border-radius:var(--r);padding:10px 18px
}
.exam-badge .pts{font-family:'DM Serif Display',serif;font-size:1.6rem;line-height:1}
.exam-badge .lbl{font-size:.65rem;letter-spacing:.08em;text-transform:uppercase;opacity:.75;margin-top:2px}

/* ── Q-nav ── */
.qnav{display:flex;gap:8px;margin-bottom:20px;flex-wrap:wrap}
.qbtn{
  padding:8px 16px;border-radius:4px;font-size:.8rem;font-weight:500;
  border:1.5px solid var(--rule);background:#fff;color:var(--soft);cursor:pointer;
  transition:.15s;font-family:'DM Sans',sans-serif
}
.qbtn:hover{border-color:var(--cm);color:var(--c)}
.qbtn.active{background:var(--c);border-color:var(--c);color:#fff}

/* ── Question card ── */
.qcard{
  background:#fff;border:1.5px solid var(--rule);border-radius:var(--r);
  padding:28px 30px;margin-bottom:20px;display:none
}
.qcard.show{display:block}
.qnum{
  font-size:.68rem;font-weight:600;letter-spacing:.12em;text-transform:uppercase;
  color:var(--c);margin-bottom:6px;display:flex;align-items:center;gap:8px
}
.qnum .pts-chip{
  background:var(--cl);color:var(--c);border-radius:20px;
  padding:2px 9px;font-size:.65rem;font-weight:600
}
.qcard h2{font-family:'DM Serif Display',serif;font-size:1.35rem;color:var(--ink);margin-bottom:4px}
.qcard .intro{font-size:.85rem;color:var(--soft);margin-bottom:18px;line-height:1.55;
  background:var(--warn-l);border-left:3px solid #C8A010;padding:10px 14px;border-radius:3px}

/* ── Dialogue/passage context ── */
.ctx-label{
  font-size:.72rem;letter-spacing:.08em;text-transform:uppercase;color:var(--soft);
  margin-bottom:10px;font-weight:500
}
.dialogue{
  background:var(--page);border:1px solid var(--rule);border-radius:4px;
  padding:18px 20px;margin-bottom:22px
}
.dialogue-item{
  display:flex;flex-direction:column;gap:4px;
  padding:9px 0;border-bottom:1px solid var(--rule);font-size:.88rem
}
.dialogue-item:last-child{border-bottom:none;padding-bottom:0}
.dl-sentence{line-height:1.6;color:var(--ink)}
.dl-blank-wrap{display:inline-flex;align-items:center;gap:6px;flex-wrap:wrap;margin-top:3px}
.blank-input{
  border:none;border-bottom:2px solid var(--cm);background:transparent;
  font-family:'DM Sans',sans-serif;font-size:.88rem;color:var(--ink);
  padding:2px 4px;min-width:130px;outline:none;transition:.15s
}
.blank-input:focus{border-bottom-color:var(--c)}
.blank-input.correct{border-bottom-color:var(--pass);background:var(--pass-l);color:var(--pass);border-radius:3px;padding:2px 6px}
.blank-input.wrong{border-bottom-color:var(--fail);background:var(--fail-l);color:var(--fail);border-radius:3px;padding:2px 6px}
.answer-reveal{
  font-size:.78rem;color:var(--pass);font-weight:600;margin-left:4px;
  display:none
}
.answer-reveal.show{display:inline}

/* ── Passage fill-in ── */
.passage-block{
  background:var(--page);border:1px solid var(--rule);border-radius:4px;
  padding:18px 22px;font-size:.88rem;line-height:2.1;color:var(--ink)
}
.p-blank{display:inline-flex;align-items:baseline;gap:3px}
.p-blank .blank-input{min-width:110px}
.p-num{
  font-size:.68rem;font-weight:700;color:var(--cm);
  vertical-align:super;margin-right:1px
}

/* ── Reading text ── */
.reading-text{
  background:var(--page);border:1px solid var(--rule);border-radius:4px;
  padding:20px 24px;font-size:.87rem;line-height:1.75;color:var(--ink);
  margin-bottom:22px
}
.reading-text strong{font-weight:600}
.reading-text em{font-style:italic;color:var(--soft)}

/* ── Listening scripts ── */
.scripts-wrap{margin-bottom:22px}
.script-card{
  border:1px solid var(--rule);border-radius:4px;margin-bottom:12px;overflow:hidden
}
.script-head{
  display:flex;align-items:center;justify-content:space-between;
  padding:10px 16px;background:var(--cl);cursor:pointer;
  font-size:.82rem;font-weight:500;color:var(--c);user-select:none
}
.script-head .toggle{font-size:.72rem;opacity:.6;margin-left:8px}
.script-body{
  font-size:.83rem;line-height:1.72;color:var(--ink);
  padding:0 16px;max-height:0;overflow:hidden;transition:max-height .3s ease,padding .3s
}
.script-body.open{max-height:400px;padding:12px 16px}
.teacher-note{
  background:var(--warn-l);border:1px solid #D4A830;border-radius:4px;
  padding:10px 14px;font-size:.78rem;color:var(--warn);margin-bottom:14px;
  display:flex;align-items:flex-start;gap:8px
}

/* ── T/F questions ── */
.tf-list{display:flex;flex-direction:column;gap:10px}
.tf-item{
  display:flex;align-items:flex-start;gap:12px;
  padding:10px 14px;background:var(--page);border-radius:4px;
  border:1px solid var(--rule);font-size:.86rem
}
.tf-num{font-weight:600;color:var(--c);min-width:22px;font-size:.8rem;padding-top:1px}
.tf-text{flex:1;line-height:1.55;color:var(--ink)}
.tf-btns{display:flex;gap:6px;flex-shrink:0}
.tf-btn{
  padding:4px 12px;border-radius:3px;font-size:.75rem;font-weight:600;
  border:1.5px solid var(--rule);background:#fff;cursor:pointer;
  font-family:'DM Sans',sans-serif;transition:.15s;color:var(--soft)
}
.tf-btn:hover{border-color:var(--cm);color:var(--c)}
.tf-btn.sel-T{background:var(--pass-l);border-color:var(--pass);color:var(--pass)}
.tf-btn.sel-F{background:var(--fail-l);border-color:var(--fail);color:var(--fail)}
.tf-btn.correct{background:var(--pass);border-color:var(--pass);color:#fff}
.tf-btn.wrong{background:var(--fail);border-color:var(--fail);color:#fff}
.tf-result{font-size:.72rem;margin-left:4px;display:none;font-weight:600;padding-top:2px}
.tf-result.show{display:block}
.tf-result.ok{color:var(--pass)}
.tf-result.bad{color:var(--fail)}

/* ── Writing ── */
.writing-prompt{
  background:var(--cl);border-left:3px solid var(--c);border-radius:4px;
  padding:18px 20px;margin-bottom:18px;font-size:.87rem;line-height:1.7;color:var(--ink)
}
.writing-prompt strong{font-weight:600}
.word-area-wrap{position:relative;margin-bottom:10px}
textarea.writing-area{
  width:100%;min-height:180px;resize:vertical;
  border:1.5px solid var(--rule);border-radius:4px;padding:14px 16px;
  font-family:'DM Sans',sans-serif;font-size:.87rem;line-height:1.65;color:var(--ink);
  background:#fff;outline:none;transition:.15s
}
textarea.writing-area:focus{border-color:var(--cm)}
.word-count{
  text-align:right;font-size:.75rem;color:var(--soft);margin-top:4px
}
.word-count.ok{color:var(--pass);font-weight:600}
.word-count.warn{color:var(--fail);font-weight:600}
.checklist-title{font-size:.75rem;font-weight:600;letter-spacing:.06em;text-transform:uppercase;color:var(--soft);margin-bottom:10px}
.checklist{display:flex;flex-direction:column;gap:7px}
.check-item{display:flex;align-items:center;gap:10px;font-size:.82rem;color:var(--ink);cursor:pointer}
.check-item input[type=checkbox]{accent-color:var(--c);width:15px;height:15px;cursor:pointer}
.check-item.done{color:var(--pass)}

/* ── Speaking ── */
.speaking-prompt{
  background:var(--cl);border-left:3px solid var(--c);border-radius:4px;
  padding:18px 20px;margin-bottom:18px;font-size:.87rem;line-height:1.7;color:var(--ink)
}
.speaking-prompt strong{font-weight:600}
.timer-wrap{
  display:flex;align-items:center;gap:14px;margin-bottom:20px;
  background:var(--page);border:1px solid var(--rule);padding:14px 18px;border-radius:4px
}
.timer-display{
  font-family:'DM Serif Display',serif;font-size:2.2rem;color:var(--c);
  min-width:70px;letter-spacing:.03em
}
.timer-display.running{color:var(--pass)}
.timer-display.over{color:var(--fail)}
.timer-btns{display:flex;gap:8px;flex-wrap:wrap}
.tbtn{
  padding:8px 16px;border-radius:4px;font-size:.8rem;font-weight:500;
  border:1.5px solid var(--rule);background:#fff;cursor:pointer;
  font-family:'DM Sans',sans-serif;transition:.15s;color:var(--ink)
}
.tbtn:hover{border-color:var(--cm);color:var(--c)}
.tbtn.primary{background:var(--c);border-color:var(--c);color:#fff}
.tbtn.primary:hover{opacity:.88}
.timer-hint{font-size:.75rem;color:var(--soft);line-height:1.5}

/* ── Score summary ── */
.score-bar{
  background:#fff;border:1.5px solid var(--rule);border-radius:var(--r);
  padding:20px 24px;margin-bottom:20px;display:flex;align-items:center;gap:20px;flex-wrap:wrap
}
.score-bar h3{font-family:'DM Serif Display',serif;font-size:1.1rem;color:var(--ink)}
.score-totals{display:flex;gap:16px;margin-left:auto;flex-wrap:wrap}
.score-cell{text-align:center}
.score-cell .val{font-family:'DM Serif Display',serif;font-size:1.4rem;color:var(--c)}
.score-cell .lbl{font-size:.65rem;letter-spacing:.08em;text-transform:uppercase;color:var(--soft)}

/* ── Utility ── */
.divider{height:1px;background:var(--rule);margin:22px 0}
.part-title{
  font-size:.7rem;font-weight:700;letter-spacing:.1em;text-transform:uppercase;
  color:var(--cm);margin-bottom:14px;padding-bottom:8px;border-bottom:1px solid var(--rule)
}
.hidden{display:none}

/* ── Responsive ── */
@media(max-width:600px){
  .shell{padding:16px 12px}
  .topbar{padding:12px 16px}
  .version-bar{padding:0 12px;overflow-x:auto}
  .qcard{padding:20px 16px}
  .tf-item{flex-wrap:wrap}
  .exam-header{flex-direction:column;gap:12px;text-align:center}
  .exam-badge{margin-left:0}
}