/* ===========================================================
   ธีมพาสเทล — นุ่ม กลม อ่านง่าย รองรับทั้งโหมดสว่างและมืด
   =========================================================== */
:root{
  --bg1:#fff5f8; --bg2:#f3f1ff; --bg3:#eefaf7;
  --card:#ffffff; --card2:#fffafc;
  --line:#ebdfe9; --line2:#e2d9f2;
  --ink:#463f59; --ink2:#332d47; --dim:#8a8199;

  --pink:#f7729d; --pink-s:#fff0f5;
  --blue:#6d84ee; --blue-s:#eff3ff;
  --mint:#3cb894; --mint-s:#e9f9f4;
  --peach:#ffbe7d;

  --ok:#37bf97; --ok-s:#e6f9f2;
  --bad:#ff7d97; --bad-s:#fff0f3;
  --gold:#e8a33d; --gold-s:#fff7e8;

  --sh:0 6px 18px rgba(150,120,160,.10);
  --sh-lift:0 12px 28px rgba(150,120,160,.18);
  --thai:"Noto Sans Thai","Sukhumvit Set","Thonburi","Leelawadee UI",system-ui,sans-serif;
  --r:22px;
}
@media (prefers-color-scheme:dark){
  :root{
    --bg1:#241f2e; --bg2:#1d1b2a; --bg3:#1b2029;
    --card:#2c2739; --card2:#332c42;
    --line:#3d3550; --line2:#3d3550;
    --ink:#f0eaf6; --ink2:#ffffff; --dim:#a79fb8;
    --pink-s:#3d2b38; --blue-s:#2b3048; --mint-s:#233b38;
    --ok-s:#233b38; --bad-s:#3f2830; --gold-s:#3b3125;
    --sh:0 6px 18px rgba(0,0,0,.28);
    --sh-lift:0 12px 28px rgba(0,0,0,.4);
  }
}

*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html,body{margin:0;padding:0}
body{
  background:
    radial-gradient(900px 520px at 12% -6%, var(--bg1) 0%, transparent 62%),
    radial-gradient(800px 500px at 92% 4%, var(--bg3) 0%, transparent 60%),
    var(--bg2);
  background-attachment:fixed;
  color:var(--ink); font-family:var(--thai); min-height:100vh;
  padding:0 16px calc(24px + env(safe-area-inset-bottom)) 16px;
  line-height:1.6;
}
#app{max-width:680px;margin:0 auto}
.screen{display:none;padding:20px 0 40px;animation:pop-in .3s cubic-bezier(.34,1.3,.5,1)}
.screen.active{display:block}
@keyframes pop-in{from{opacity:0;transform:translateY(10px) scale(.99)}to{opacity:1;transform:none}}

/* ---------------- หัวเรื่อง ---------------- */
.hero{text-align:center;padding:26px 0 20px}
.hero-sm{padding:10px 0 16px}
.hero-badge{
  display:inline-block;font-size:13px;font-weight:600;color:var(--pink);
  background:var(--pink-s);border:1.5px solid var(--pink);
  padding:6px 18px;border-radius:999px;margin-bottom:14px
}
.hero h1{font-size:clamp(24px,5.6vw,32px);margin:0 0 8px;font-weight:800;color:var(--ink2);line-height:1.4}
.hero-sub{color:var(--dim);font-size:14.5px;margin:0;line-height:1.75}
.foot{text-align:center;color:var(--dim);font-size:12.5px;margin-top:28px;line-height:1.9}

/* ---------------- การ์ดวิชา ---------------- */
.subject-grid{display:grid;gap:15px}
.subj{
  display:block;width:100%;cursor:pointer;font-family:inherit;color:var(--ink);
  background:var(--card);border:2px solid var(--line);border-radius:26px;
  padding:18px;box-shadow:var(--sh);transition:transform .18s cubic-bezier(.34,1.4,.5,1),box-shadow .18s,border-color .18s
}
@media (hover:hover){.subj:hover{transform:translateY(-4px);border-color:color-mix(in srgb, var(--sc,#f7729d) 55%, var(--line));box-shadow:var(--sh-lift)}}
.subj:active{transform:translateY(-1px) scale(.99)}
.subj-inner{display:flex;align-items:center;gap:15px;text-align:left}
.subj-ico{
  flex:0 0 56px;height:56px;border-radius:20px;display:grid;place-items:center;
  font-size:27px;background:var(--card2);border:2px solid var(--line);
  background:color-mix(in srgb, var(--sc,#f7729d) 13%, var(--card));
  border-color:color-mix(in srgb, var(--sc,#f7729d) 32%, var(--line))
}
.subj-txt{flex:1;min-width:0}
.subj-code{font-size:12px;font-weight:700;letter-spacing:.04em;color:var(--sc,var(--pink))}
.subj-name{font-size:18px;font-weight:800;color:var(--ink2);margin:2px 0 4px;line-height:1.35}
.subj-desc{font-size:12.5px;color:var(--dim);line-height:1.6}

/* ---------------- รายการพาร์ท ---------------- */
.part-list{display:grid;gap:14px}
.part{
  cursor:pointer;font-family:inherit;color:var(--ink);text-align:left;
  background:var(--card);border:2px solid var(--line);border-radius:24px;
  padding:17px 18px;box-shadow:var(--sh);display:flex;align-items:center;gap:15px;
  transition:transform .18s cubic-bezier(.34,1.4,.5,1),box-shadow .18s,border-color .18s
}
@media (hover:hover){.part:hover{transform:translateY(-4px);border-color:var(--blue);box-shadow:var(--sh-lift)}}
.part:active{transform:translateY(-1px) scale(.99)}
.part-n{
  flex:0 0 46px;height:46px;border-radius:16px;display:grid;place-items:center;
  font-weight:800;font-size:18px;color:#fff;
  background:linear-gradient(140deg,var(--blue),var(--pink));
  box-shadow:0 4px 10px rgba(124,156,255,.35)
}
.part-b{flex:1;min-width:0}
.part-t{font-weight:800;font-size:16px;color:var(--ink2);margin-bottom:3px}
.part-d{font-size:12.5px;color:var(--dim);line-height:1.7}
.part-q{font-size:12px;color:var(--mint);font-weight:600;margin-top:6px}
.back-btn{
  background:var(--card);border:2px solid var(--line);color:var(--dim);
  font-family:inherit;font-size:14px;font-weight:600;cursor:pointer;
  padding:8px 16px;border-radius:999px;box-shadow:var(--sh);transition:.16s
}
.back-btn:hover{color:var(--ink2);border-color:var(--pink)}

/* ---------------- หน้าทำข้อสอบ ---------------- */
.quiz-top{display:flex;align-items:center;justify-content:space-between;gap:10px;padding:14px 4px 12px}
.quit-btn{
  background:none;border:none;color:var(--dim);font-family:inherit;font-size:14px;
  font-weight:600;cursor:pointer;padding:4px 6px;border-radius:12px
}
.quit-btn:hover{color:var(--bad);background:var(--bad-s)}
.quiz-meta{font-size:12.5px;color:var(--dim);display:flex;gap:7px;align-items:center;min-width:0}
.quiz-meta span{white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.dot{opacity:.45}
.timer{font-variant-numeric:tabular-nums;color:var(--blue);font-weight:700}
.quiz-count{font-size:15px;font-weight:800;color:var(--dim);font-variant-numeric:tabular-nums}
.quiz-count span:first-child{color:var(--pink)}

.progress{height:10px;background:var(--card);border:2px solid var(--line);border-radius:999px;overflow:hidden;margin-bottom:20px}
.progress-bar{
  height:100%;width:0;border-radius:999px;
  background:linear-gradient(90deg,var(--blue),var(--pink),var(--peach));
  transition:width .35s cubic-bezier(.34,1.2,.5,1)
}

.qcard{
  background:var(--card);border:2px solid var(--line);border-radius:26px;
  padding:22px 20px;margin-bottom:16px;box-shadow:var(--sh)
}
.qbank{font-size:11.5px;font-weight:600;color:var(--dim);margin-bottom:9px}
.qtext{font-size:17.5px;line-height:2.1;color:var(--ink2);font-weight:600}

.choices{display:grid;gap:11px}
.ch{
  display:flex;align-items:center;gap:14px;cursor:pointer;width:100%;text-align:left;
  background:var(--card);border:2px solid var(--line);border-radius:20px;
  padding:15px 17px;color:var(--ink);font-family:inherit;font-size:16.5px;
  box-shadow:var(--sh);transition:transform .16s cubic-bezier(.34,1.4,.5,1),border-color .16s,background .16s
}
@media (hover:hover){
  .ch:hover:not(:disabled):not(.selected):not(.right):not(.wrong){
    border-color:var(--blue);transform:translateY(-2px)
  }
}
.ch:disabled{cursor:default;box-shadow:none}
.ch-k{
  flex:0 0 34px;height:34px;border-radius:12px;display:grid;place-items:center;
  font-weight:800;font-size:14px;background:var(--card2);
  border:2px solid var(--line);color:var(--dim);transition:.16s
}
.ch-v{flex:1;min-width:0;line-height:1.95}

/* กำลังเลือกอยู่ (ยังไม่ยืนยัน) */
.ch.selected,.ch.selected:hover{
  border-color:var(--pink);background:var(--pink-s);
  transform:translateY(-2px) scale(1.012);
  box-shadow:0 8px 20px rgba(247,114,157,.3)
}
.ch.selected .ch-k{background:var(--pink);border-color:var(--pink);color:#fff}
.ch.selected .ch-v{font-weight:700}
/* วงกลมไอคอนบอกสถานะของตัวเลือก */
.ch-mark{
  flex:0 0 26px;width:26px;height:26px;border-radius:50%;
  display:grid;place-items:center;margin-left:6px;
  background:transparent;color:#fff;opacity:0;transform:scale(.5);
  transition:opacity .16s,transform .2s cubic-bezier(.34,1.6,.5,1)
}
.ch-mark .ic{width:16px;height:16px;stroke-width:2.8}
.mk-check,.mk-x{display:none}
.ch.selected .ch-mark{background:var(--pink);opacity:1;transform:scale(1)}
.ch.selected .mk-check{display:block}
.ch.right .ch-mark{background:var(--ok);opacity:1;transform:scale(1)}
.ch.right .mk-check{display:block}
.ch.wrong .ch-mark{background:var(--bad);opacity:1;transform:scale(1)}
.ch.wrong .mk-x{display:block}
/* เฉลย */
.ch.right{border-color:var(--ok);background:var(--ok-s)}
.ch.right .ch-k{background:var(--ok);border-color:var(--ok);color:#fff}
.ch.wrong{border-color:var(--bad);background:var(--bad-s);animation:shake .34s}
.ch.wrong .ch-k{background:var(--bad);border-color:var(--bad);color:#fff}
@keyframes shake{0%,100%{transform:translateX(0)}22%{transform:translateX(-7px)}55%{transform:translateX(6px)}80%{transform:translateX(-3px)}}

/* ---------------- แถบยืนยันคำตอบ ---------------- */
.confirm-bar{
  position:sticky;bottom:0;z-index:5;margin-top:16px;
  padding:13px 0 calc(12px + env(safe-area-inset-bottom));
  background:linear-gradient(to top,var(--bg2) 62%,transparent);
  display:grid;gap:9px;justify-items:center
}
.confirm-hint{font-size:13px;color:var(--dim);text-align:center;line-height:1.6;transition:.2s}
.confirm-bar.ready .confirm-hint{color:var(--pink);font-weight:600}
.btn-confirm{
  width:100%;background:linear-gradient(135deg,#5f76e8,#ee5b8c);color:#fff;
  border:none;font-size:17px;font-weight:800;padding:16px;border-radius:20px;
  box-shadow:0 8px 20px rgba(255,144,179,.38);cursor:pointer;
  transition:transform .16s cubic-bezier(.34,1.4,.5,1),opacity .16s,box-shadow .16s
}
.btn-confirm:hover:not(:disabled){transform:translateY(-2px);box-shadow:0 12px 26px rgba(255,144,179,.5)}
.btn-confirm:active:not(:disabled){transform:translateY(0) scale(.985)}
.btn-confirm:disabled{
  background:var(--card);color:var(--dim);border:2px solid var(--line);
  box-shadow:none;cursor:not-allowed
}

/* ---------------- หน้าผลลัพธ์ ---------------- */
.result{
  text-align:center;padding:34px 22px 28px;border-radius:30px;margin-top:16px;
  border:2px solid var(--line);background:var(--card);box-shadow:var(--sh-lift)
}
.result h1{font-size:26px;margin:0 0 10px;font-weight:800;color:var(--ink2)}
.result-icon{
  width:82px;height:82px;border-radius:50%;display:grid;place-items:center;
  font-size:40px;margin:0 auto 16px
}
.fail .result-icon{background:var(--bad-s);border:2.5px solid var(--bad)}
.pass{border-color:var(--ok);background:linear-gradient(170deg,var(--ok-s) 0%,var(--card) 48%)}
.pass .result-icon{background:var(--ok-s);border:2.5px solid var(--ok);animation:bounce .6s cubic-bezier(.34,1.7,.5,1)}
@keyframes bounce{0%{transform:scale(0) rotate(-25deg)}60%{transform:scale(1.15) rotate(6deg)}100%{transform:scale(1) rotate(0)}}
.pass-stamp{
  display:inline-block;font-size:13px;font-weight:800;letter-spacing:.1em;color:#fff;
  background:linear-gradient(135deg,var(--mint),var(--ok));
  border-radius:999px;padding:7px 22px;margin-bottom:14px;
  box-shadow:0 5px 14px rgba(55,191,151,.34)
}
.pass h1{font-size:23px;line-height:1.4}
.pass-part{color:var(--dim);font-size:14px;margin-bottom:16px}
.pass-score{
  font-size:50px;font-weight:900;line-height:1.05;font-variant-numeric:tabular-nums;
  background:linear-gradient(135deg,var(--mint),var(--blue));
  -webkit-background-clip:text;background-clip:text;color:transparent
}
.pass-score small{display:block;font-size:13px;font-weight:600;color:var(--dim);margin-top:5px;-webkit-text-fill-color:var(--dim)}

.result-lead{color:var(--dim);font-size:15px;margin:0 0 16px;line-height:1.85}
.result-box{
  background:var(--card2);border:2px solid var(--line);border-radius:20px;
  padding:4px 17px;margin:20px 0;text-align:left
}
.teacher-box{border-color:var(--ok);background:var(--ok-s)}
.rb-row{
  display:flex;justify-content:space-between;align-items:center;gap:12px;
  padding:13px 0;font-size:14.5px;border-bottom:1.5px dashed var(--line)
}
.rb-row:last-child{border-bottom:none}
.rb-row span{color:var(--dim);white-space:nowrap}
.rb-row b{font-weight:700;text-align:right;color:var(--ink2);font-variant-numeric:tabular-nums}
.result-note{color:var(--dim);font-size:13.5px;line-height:1.9;margin:0}
.bless{font-size:15.5px;line-height:2.05;color:var(--ink2);margin:18px 0;font-weight:600}
.teacher-note{
  background:var(--gold-s);border:2px dashed var(--gold);color:var(--gold);
  border-radius:18px;padding:14px;font-size:14px;font-weight:700;line-height:1.75;margin-top:6px
}

.result-actions{display:grid;gap:11px;margin-top:24px}
.btn{
  cursor:pointer;font-family:inherit;font-size:16px;font-weight:700;
  border-radius:18px;padding:15px 20px;border:2px solid transparent;transition:.16s
}
.btn-primary{
  background:linear-gradient(135deg,#5f76e8,#ee5b8c);color:#fff;
  box-shadow:0 8px 20px rgba(238,91,140,.34)
}
.btn-primary:hover{transform:translateY(-2px)}
.btn-ghost{background:var(--card);color:var(--dim);border-color:var(--line)}
.btn-ghost:hover{color:var(--ink2);border-color:var(--dim)}

/* ---------------- ระบบไอคอน SVG ---------------- */
.sprite{display:none}
.ic{
  width:1.15em;height:1.15em;flex:0 0 auto;vertical-align:-.2em;
  fill:none;stroke:currentColor;stroke-width:1.9;
  stroke-linecap:round;stroke-linejoin:round
}
.ic .fill{fill:currentColor;stroke:none}
.ic .nostroke{stroke:none}
.ic-xl{width:30px;height:30px;stroke-width:1.7}
.ic-spark{width:17px;height:17px;color:var(--gold);margin-right:5px}

.back-btn,.quit-btn,.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px}
.subj-arrow{width:20px;height:20px;color:var(--dim);stroke-width:2.4}
.rb-row span{display:inline-flex;align-items:center;gap:8px}
.rb-row .ic{width:17px;height:17px;color:var(--dim)}
.teacher-note{display:flex;align-items:center;justify-content:center;gap:9px;text-align:left}
.teacher-note .ic{width:19px;height:19px;flex:0 0 auto}
.pass-stamp{display:inline-flex;align-items:center;gap:7px}
.pass-stamp .ic{width:16px;height:16px;stroke-width:2.2}
.result-icon .ic{width:40px;height:40px;stroke-width:2.4}
.fail .result-icon .ic{color:var(--bad)}
.pass .result-icon .ic{color:var(--ok)}
.bless{display:flex;align-items:flex-start;justify-content:center;gap:2px;text-align:left}
.bless .ic-spark{margin-top:6px}
.quit-btn .ic{width:15px;height:15px;stroke-width:2.6}
.back-btn .ic{width:15px;height:15px;stroke-width:2.6}
.btn .ic{width:19px;height:19px;stroke-width:2.3}

/* ---------------- KaTeX ---------------- */
.katex{font-size:1.08em}
.ch-v .katex{font-size:1.05em}

@media (prefers-reduced-motion:reduce){
  *{animation-duration:.01ms!important;transition-duration:.01ms!important}
}