/* EngPass — ธีมกลาง: กระดาษสมุดข้อสอบ + หมึกแดงกระดาษคำตอบ (OMR dropout ink) + ไส้ดินสอ */
:root{
  --bg:#f3f5f8; --sheet:#ffffff; --sheet-2:#f8f9fb; --ink:#141b24; --muted:#5a6472; --line:#dde2e8;
  --omr:#cf3f58; --omr-ink:#b02f47; --omr-soft:#fbe8ec; --graphite:#262b33; --on-graphite:#ffffff;
  --ok:#17784c; --ok-soft:#e3f3ea; --bad:#b4232f; --bad-soft:#fbe6e7; --warn:#8a5a00; --warn-soft:#fff3d6;
  --focus:#2f6fd6; --shadow:0 1px 2px rgba(20,27,36,.06),0 6px 20px rgba(20,27,36,.06);
  --r:12px; --sans:"IBM Plex Sans Thai","IBM Plex Sans",system-ui,-apple-system,"Segoe UI",sans-serif;
  --serif:"IBM Plex Serif",Georgia,"Times New Roman",serif;
  color-scheme:light;
}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){
  --bg:#0f1318; --sheet:#171c23; --sheet-2:#1c222a; --ink:#e7eaef; --muted:#9ba5b3; --line:#2b323c;
  --omr:#ec6b80; --omr-ink:#f28a9b; --omr-soft:#3a1f27; --graphite:#e7eaef; --on-graphite:#11151a;
  --ok:#4cc38a; --ok-soft:#14301f; --bad:#f07178; --bad-soft:#3a1c1f; --warn:#f0b549; --warn-soft:#33270c;
  --focus:#7aa7ff; --shadow:0 1px 2px rgba(0,0,0,.3),0 6px 20px rgba(0,0,0,.25); color-scheme:dark}}
:root[data-theme="dark"]{
  --bg:#0f1318; --sheet:#171c23; --sheet-2:#1c222a; --ink:#e7eaef; --muted:#9ba5b3; --line:#2b323c;
  --omr:#ec6b80; --omr-ink:#f28a9b; --omr-soft:#3a1f27; --graphite:#e7eaef; --on-graphite:#11151a;
  --ok:#4cc38a; --ok-soft:#14301f; --bad:#f07178; --bad-soft:#3a1c1f; --warn:#f0b549; --warn-soft:#33270c;
  --focus:#7aa7ff; --shadow:0 1px 2px rgba(0,0,0,.3),0 6px 20px rgba(0,0,0,.25); color-scheme:dark}

*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.65 var(--sans)}
a{color:var(--omr-ink)}
img{max-width:100%;display:block}
h1,h2,h3{line-height:1.25;text-wrap:balance;margin:0}
button{font:inherit;color:inherit}
:focus-visible{outline:2px solid var(--focus);outline-offset:2px}
.wrap{max-width:1080px;margin:0 auto;padding-inline:16px}
.muted{color:var(--muted)}
.tnum{font-variant-numeric:tabular-nums}
.lbl{font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);font-weight:600}

/* ---------- ปุ่ม ---------- */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:46px;padding:0 20px;border-radius:10px;border:1px solid var(--line);background:var(--sheet);font-weight:600;cursor:pointer;text-decoration:none;color:var(--ink)}
.btn.primary{background:var(--omr);border-color:var(--omr);color:#fff}
.btn.dark{background:var(--graphite);border-color:var(--graphite);color:var(--on-graphite)}
.btn.ghost{background:transparent}
.btn.sm{min-height:36px;padding:0 12px;font-size:14px;border-radius:8px}
.btn:disabled{opacity:.5;cursor:not-allowed}

/* ---------- แถบบน ---------- */
.top{position:sticky;top:env(safe-area-inset-top,0px);z-index:20;background:var(--sheet);border-bottom:1px solid var(--line)}
.top .wrap{display:flex;align-items:center;gap:12px;min-height:56px}
.top .btn{white-space:nowrap}
@media (max-width:420px){.top .wrap{gap:6px}.top .btn.sm{padding-inline:9px;font-size:13px}.top .brand{font-size:15px}}
@media (max-width:359px){.top .hide-xs{display:none}}
.brand{display:flex;align-items:center;gap:8px;font-weight:700;text-decoration:none;color:var(--ink);letter-spacing:-.01em}
.brand-mark{width:26px;height:26px;border-radius:50%;border:2px solid var(--omr);display:grid;place-items:center;font-size:11px;font-weight:700;color:var(--omr-ink)}
.brand-mark::after{content:"";width:12px;height:12px;border-radius:50%;background:var(--graphite)}
.spacer{flex:1}

/* ---------- ฟองคำตอบ (หัวใจของดีไซน์) ---------- */
.bubbles{display:flex;gap:10px;flex-wrap:wrap}
.bub{width:44px;height:44px;border-radius:50%;border:2px solid var(--omr);background:var(--sheet);color:var(--omr-ink);font-weight:700;font-size:16px;display:grid;place-items:center;cursor:pointer;transition:background .12s,color .12s}
.bub[aria-pressed="true"]{background:var(--graphite);border-color:var(--graphite);color:var(--on-graphite)}
.bub.sm{width:26px;height:26px;font-size:11px;border-width:1.5px}

/* ---------- หน้าข้อสอบ ---------- */
.exam-bar{display:flex;align-items:center;gap:10px;flex-wrap:wrap}
.chip{display:inline-flex;align-items:center;gap:6px;padding:4px 10px;border-radius:999px;background:var(--omr-soft);color:var(--omr-ink);font-size:13px;font-weight:600}
.timer{font:600 18px/1 var(--sans);font-variant-numeric:tabular-nums}
.timer.low{color:var(--bad)}
.progress{height:4px;background:var(--line);border-radius:4px;overflow:hidden}
.progress>i{display:block;height:100%;background:var(--omr);width:0}

.book{background:var(--sheet);border:1px solid var(--line);border-radius:var(--r);box-shadow:var(--shadow);padding:20px}
.book + .book{margin-top:16px}
.book .serif,.passage,.q-text,.choice-text{font-family:var(--serif)}
.part-head{display:flex;align-items:baseline;gap:10px;margin-bottom:12px}
.part-head h2{font-size:20px}
.photo{border-radius:8px;border:1px solid var(--line);width:100%;max-width:640px;aspect-ratio:4/3;object-fit:cover;background:var(--sheet-2)}
.qno{font-weight:700;font-variant-numeric:tabular-nums}

.q{padding:14px 0;border-top:1px solid var(--line)}
.q:first-child{border-top:0;padding-top:0}
.q-text{font-size:17px;margin:0 0 10px}
.choices{display:grid;gap:8px}
.choice{display:flex;align-items:flex-start;gap:12px;padding:8px 10px;border-radius:10px;border:1px solid transparent;cursor:pointer;text-align:left;background:none;width:100%}
.choice:hover{background:var(--sheet-2)}
.choice .bub{width:32px;height:32px;font-size:14px;flex:none}
.choice-text{padding-top:4px;font-size:16px}
.choice[aria-pressed="true"]{border-color:var(--line);background:var(--sheet-2)}
.choice[aria-pressed="true"] .bub{background:var(--graphite);border-color:var(--graphite);color:var(--on-graphite)}

.passage{white-space:pre-wrap;font-size:16px;line-height:1.7;background:var(--sheet-2);border:1px solid var(--line);border-radius:10px;padding:16px;overflow-wrap:anywhere}
.passage + .passage{margin-top:12px}
.passage .ptitle{display:block;font-family:var(--sans);font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin-bottom:6px}
.blank{display:inline-block;min-width:4.5em;border-bottom:2px solid var(--ink);text-align:center;font-family:var(--sans);font-weight:700;font-size:13px;color:var(--omr-ink);padding:0 4px;line-height:1.3}
.blank.filled{background:var(--omr-soft)}

.split{display:grid;gap:16px}
@media (min-width:900px){.split{grid-template-columns:minmax(0,1.1fr) minmax(0,1fr);align-items:start}
  .split .stick{position:sticky;top:calc(env(safe-area-inset-top,0px) + 130px);max-height:calc(100vh - 150px);overflow:auto}}

.gtable{overflow-x:auto;margin:6px 0 14px}
.gtable table{border-collapse:collapse;font-size:15px;min-width:280px}
.gtable caption{text-align:left;font-weight:700;padding:0 0 6px}
.gtable th,.gtable td{border:1px solid var(--line);padding:6px 10px;text-align:left}
.gtable th{background:var(--sheet-2)}

.pager{display:flex;align-items:center;gap:10px;justify-content:space-between;margin-top:16px}

/* ---------- กระดาษคำตอบ (โมดัล) ---------- */
.modal{position:fixed;inset:0;z-index:50;background:rgba(10,14,20,.45);display:flex;align-items:flex-end;justify-content:center}
@media (min-width:700px){.modal{align-items:center}}
.sheet-panel{background:var(--sheet);width:100%;max-width:720px;max-height:85vh;overflow:auto;border-radius:16px 16px 0 0;padding:18px 16px calc(18px + env(safe-area-inset-bottom,0px))}
@media (min-width:700px){.sheet-panel{border-radius:16px}}
.omr-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:4px 14px;margin-top:10px}
.omr-row{display:flex;align-items:center;gap:5px;padding:3px 4px;border-radius:6px;cursor:pointer;background:none;border:0;width:100%}
.omr-row:hover{background:var(--sheet-2)}
.omr-row .n{width:30px;text-align:right;font-size:12px;font-weight:700;color:var(--omr-ink);font-variant-numeric:tabular-nums}
.omr-row .bub{pointer-events:none}

/* ---------- ข้อความแจ้ง ---------- */
.note{border-radius:10px;padding:12px 14px;font-size:15px}
.note.warn{background:var(--warn-soft);color:var(--warn)}
.note.bad{background:var(--bad-soft);color:var(--bad)}
.note.ok{background:var(--ok-soft);color:var(--ok)}
.toast{position:fixed;left:50%;bottom:calc(20px + env(safe-area-inset-bottom,0px));transform:translateX(-50%);background:var(--graphite);color:var(--on-graphite);padding:10px 16px;border-radius:10px;z-index:60;font-size:14px;max-width:calc(100% - 32px)}

/* ---------- ผลสอบ ---------- */
.score-row{display:grid;gap:12px;grid-template-columns:repeat(auto-fit,minmax(130px,1fr))}
.score{padding:16px;border-radius:var(--r);background:var(--sheet-2);border:1px solid var(--line)}
.score b{display:block;font-size:30px;line-height:1.1;font-variant-numeric:tabular-nums}
.bars{display:grid;gap:8px;margin-top:8px}
.bar{display:grid;grid-template-columns:72px 1fr 64px;align-items:center;gap:10px;font-size:14px}
.bar .track{height:10px;background:var(--line);border-radius:6px;overflow:hidden}
.bar .track i{display:block;height:100%;background:var(--graphite)}
.bar.pace{grid-template-columns:72px 1fr 112px}.bar.pace>.tnum{text-align:right}
.bar.over .track i{background:var(--bad)}
.bar.over .tnum{color:var(--bad)}
.rv{padding:14px 0;border-top:1px solid var(--line)}
.rv .tag{font-size:12px;font-weight:700;padding:2px 8px;border-radius:999px}
.tag.ok{background:var(--ok-soft);color:var(--ok)}
.tag.bad{background:var(--bad-soft);color:var(--bad)}
.tag.skip{background:var(--sheet-2);color:var(--muted)}
.rv .ch{display:flex;gap:8px;padding:2px 0;font-family:var(--serif)}
.rv .ch.key{color:var(--ok);font-weight:600}
.rv .ch.mine{color:var(--bad)}
.why{margin-top:8px;padding:10px 12px;background:var(--sheet-2);border-left:3px solid var(--omr);border-radius:0 8px 8px 0;font-size:15px}
.tabs{display:flex;gap:6px;flex-wrap:wrap}
.tabs button{border:1px solid var(--line);background:var(--sheet);border-radius:999px;padding:6px 12px;font-size:14px;cursor:pointer}
.tabs button[aria-pressed="true"]{background:var(--graphite);color:var(--on-graphite);border-color:var(--graphite)}
details.script{margin:8px 0;font-size:15px}
details.script summary{cursor:pointer;color:var(--omr-ink);font-weight:600}
details.script p{margin:4px 0;font-family:var(--serif)}
.footer{padding-block:32px;color:var(--muted);font-size:13px}