/* =========================================================
   Kru Physics OS · Interactive Lab — Design System (kp.css)
   ใช้ร่วมกันทุกหน้า: โทเคนสี, ตัวอักษร, คอมโพเนนต์, โหมดครู/นักเรียน
   ========================================================= */

:root {
  --bg: #f5f6fb;
  --bg-soft: #eceffa;
  --surface: #ffffff;
  --surface-2: #f8f9fe;
  --ink: #1d2140;
  --muted: #525a7a;
  --line: #e1e5f2;
  --primary: #4b4bc9;
  --primary-ink: #ffffff;
  --primary-soft: #e8e8fd;
  --accent: #ff8a5b;
  --good: #16794d;
  --good-soft: #dff5ea;
  --bad: #c62f34;
  --bad-soft: #fde4e4;
  --warn: #a8570a;
  --warn-soft: #fff3d6;

  /* สีประจำสถานี 1–5 */
  --st1: #8b5cf6;
  --st2: #0ea5e9;
  --st3: #f59e0b;
  --st4: #10b981;
  --st5: #ec4899;
  /* สีสด (--st1…5, --accent) ใช้เป็นพื้น/เส้นขอบ/ไอคอนเท่านั้น
     ถ้าเป็นตัวหนังสือ ให้ใช้ชุด -ink ซึ่งผสมกับ --ink จึงผ่านคอนทราสต์ AA ทั้งโหมดสว่างและโหมดมืด
     พื้นสีสด + ตัวหนังสือ: ใช้ "พื้นจาง + ตัวหนังสือ -ink" (ดู .kp-stations .n) หรือหมึกเข้ม #1d2140 บนพื้นสีสด */
  --st1-ink: color-mix(in srgb, var(--st1) 45%, var(--ink));
  --st2-ink: color-mix(in srgb, var(--st2) 45%, var(--ink));
  --st3-ink: color-mix(in srgb, var(--st3) 45%, var(--ink));
  --st4-ink: color-mix(in srgb, var(--st4) 45%, var(--ink));
  --st5-ink: color-mix(in srgb, var(--st5) 45%, var(--ink));
  --accent-ink: color-mix(in srgb, var(--accent) 45%, var(--ink));
  --on-vivid: #1d2140; /* หมึกบนพื้นสีสด (คงที่ทั้งสองโหมด) */
  --blackout: #000000; --blackout-ink: #8a90a6; /* จอดำของครู (คงที่ทั้งสองโหมด) */

  /* สีสำหรับ canvas (simulation อ่านค่าจากตรงนี้) */
  --sim-bg: #f9fbff;
  --sim-grid: #e4e9f5;
  --sim-ground: #9ccf8f;
  --sim-ink: #1d2140;
  --sim-a: #5b5bd6;
  --sim-b: #ff8a5b;
  --sim-c: #10b981;
  --sim-d: #ec4899;

  --radius: 18px;
  --radius-sm: 12px;
  --shadow: 0 6px 24px rgba(40, 50, 110, .08);
  --shadow-lg: 0 18px 50px rgba(40, 50, 110, .16);
  --font-head: "Kanit", "Sarabun", system-ui, sans-serif;
  --font-body: "Sarabun", "Kanit", system-ui, sans-serif;
  --fs: 17px;
  --maxw: 1180px;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #11131d; --bg-soft: #181b29; --surface: #1b1e2e; --surface-2: #22263a;
    --ink: #eef0f8; --muted: #a6acc6; --line: #2e3350;
    --primary: #8b8bff; --primary-ink: #11131d; --primary-soft: #2a2b55;
    --good: #3ccf8e; --good-soft: #163a2b; --bad: #ff6b6f; --bad-soft: #42191d;
    --warn: #f5b942; --warn-soft: #3d3014;
    --sim-bg: #161927; --sim-grid: #262b42; --sim-ground: #3f6b44; --sim-ink: #eef0f8;
    --sim-a: #9a9aff; --sim-b: #ffa47f; --sim-c: #3ccf8e; --sim-d: #ff7ab8;
    --shadow: 0 6px 24px rgba(0, 0, 0, .35); --shadow-lg: 0 18px 50px rgba(0, 0, 0, .5);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #11131d; --bg-soft: #181b29; --surface: #1b1e2e; --surface-2: #22263a;
  --ink: #eef0f8; --muted: #a6acc6; --line: #2e3350;
  --primary: #8b8bff; --primary-ink: #11131d; --primary-soft: #2a2b55;
  --good: #3ccf8e; --good-soft: #163a2b; --bad: #ff6b6f; --bad-soft: #42191d;
  --warn: #f5b942; --warn-soft: #3d3014;
  --sim-bg: #161927; --sim-grid: #262b42; --sim-ground: #3f6b44; --sim-ink: #eef0f8;
  --sim-a: #9a9aff; --sim-b: #ffa47f; --sim-c: #3ccf8e; --sim-d: #ff7ab8;
  --shadow: 0 6px 24px rgba(0, 0, 0, .35); --shadow-lg: 0 18px 50px rgba(0, 0, 0, .5);
  color-scheme: dark;
}

/* โหมดนำเสนอ (ครูฉายจอ): ขยายทุกอย่าง */
body.kp-present { --fs: 21px; --maxw: 1500px; }

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font-family: var(--font-body); font-size: var(--fs); line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3, h4 { font-family: var(--font-head); font-weight: 600; line-height: 1.25; margin: 0 0 .5em; }
h1 { font-size: clamp(1.7rem, 4vw, 2.6rem); }
h2 { font-size: clamp(1.35rem, 3vw, 1.8rem); }
h3 { font-size: 1.15rem; }
p { margin: 0 0 .8em; }
a { color: var(--primary); }
img, canvas, svg { max-width: 100%; }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; border-radius: 6px; }
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 16px; }
.muted { color: var(--muted); }
/* ตัวยก/ตัวห้อย ไม่เล็กกว่า 12px (10⁶ กับ 10⁵ ต้องอ่านออกชัด) */
sup, sub { font-size: max(12px, .72em); }
.small { font-size: .88em; }
.center { text-align: center; }
.row { display: flex; gap: 12px; flex-wrap: wrap; align-items: center; }
.grid { display: grid; gap: 16px; }
.grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
@media (max-width: 820px) { .grid-2, .grid-3 { grid-template-columns: 1fr; } }

/* ---------- ลายน้ำ (ข้อความเดียวกลางจอ) ---------- */
.kp-watermark {
  position: fixed; inset: 0; display: grid; place-items: center;
  pointer-events: none; z-index: 1; user-select: none;
  font-family: var(--font-head); font-weight: 700;
  font-size: clamp(2.5rem, 9vw, 7rem); color: var(--ink); opacity: .04;
  transform: rotate(-18deg); white-space: nowrap;
}
main, .kp-header, .kp-footer { position: relative; z-index: 2; }

/* ---------- Header ---------- */
.kp-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--surface) 88%, transparent);
  backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.kp-header .bar { display: flex; align-items: center; gap: 10px; min-height: 60px; }
.kp-brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); font-family: var(--font-head); font-weight: 600; white-space: nowrap; }
.kp-logo { width: 34px; height: 34px; border-radius: 10px; display: grid; place-items: center; background: linear-gradient(135deg, var(--primary), var(--accent)); color: #fff; font-size: 18px; }
.kp-brand small { display: block; font-weight: 400; font-size: .75rem; color: var(--muted); line-height: 1; }
.kp-spacer { flex: 1; }
.kp-xp { display: flex; align-items: center; gap: 8px; font-family: var(--font-head); font-size: .9rem; }
.kp-xp .lv { background: var(--primary-soft); color: var(--primary); border-radius: 999px; padding: 2px 10px; font-weight: 600; }
.kp-xp .meter { width: 90px; height: 8px; background: var(--bg-soft); border-radius: 99px; overflow: hidden; }
.kp-xp .meter i { display: block; height: 100%; background: linear-gradient(90deg, var(--primary), var(--accent)); width: 0; transition: width .5s; }
@media (max-width: 640px) { .kp-xp .meter, .kp-brand small, .kp-hide-sm { display: none; } }
@media (max-width: 480px) {
  .kp-header .bar { gap: 4px; }
  .kp-brand .kp-brand-text { display: none; }
  .kp-header .btn.icon { min-width: 38px; padding: 6px; }
  .kp-mode button { padding: 6px 9px; }
}

/* ---------- ปุ่ม ---------- */
.btn {
  appearance: none; border: 1px solid var(--line); background: var(--surface); color: var(--ink);
  font: 500 .95rem var(--font-head); padding: 10px 16px; border-radius: 12px; cursor: pointer;
  display: inline-flex; align-items: center; gap: 8px; min-height: 44px; text-decoration: none;
  transition: transform .12s, background .2s, border-color .2s, box-shadow .2s;
}
.btn:hover { border-color: var(--primary); }
.btn:active { transform: scale(.97); }
.btn.primary { background: var(--primary); color: var(--primary-ink); border-color: var(--primary); }
.btn.accent { background: var(--accent); color: var(--on-vivid); border-color: var(--accent); }
.btn.ghost { background: transparent; }
.btn.sm { min-height: 36px; padding: 6px 12px; font-size: .85rem; }
.btn.icon { padding: 8px; min-width: 44px; justify-content: center; }
/* ปุ่มที่กดไม่ได้: ไม่ใช้ opacity (ตัวหนังสือจะตก AA) ใช้พื้นเทา + เส้นประ + ตัวหนังสือสีรองแทน */
.btn[disabled], .btn.primary[disabled], .btn.accent[disabled] { background: var(--surface-2); color: var(--muted); border: 1px dashed var(--line); box-shadow: none; cursor: not-allowed; transform: none; }
.btn.big { font-size: 1.1rem; padding: 14px 24px; border-radius: 14px; }

/* สวิตช์โหมด ครู/นักเรียน */
.kp-mode { display: inline-flex; background: var(--bg-soft); border-radius: 12px; padding: 3px; border: 1px solid var(--line); }
.kp-mode button { border: 0; background: transparent; color: var(--muted); font: 500 .85rem var(--font-head); padding: 6px 12px; border-radius: 9px; cursor: pointer; min-height: 36px; }
.kp-mode button[aria-pressed="true"] { background: var(--surface); color: var(--ink); box-shadow: var(--shadow); }

/* ---------- Card / Panel ---------- */
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px; box-shadow: var(--shadow); }
.card.soft { background: var(--surface-2); box-shadow: none; }
.pill { display: inline-flex; align-items: center; gap: 6px; font: 500 .78rem var(--font-head); padding: 3px 10px; border-radius: 999px; background: var(--bg-soft); color: var(--muted); }
.pill.good { background: var(--good-soft); color: var(--good); }
.pill.warn { background: var(--warn-soft); color: var(--warn); }
.pill.primary { background: var(--primary-soft); color: var(--primary); }
.pill.accent { background: var(--accent); color: var(--on-vivid); }
.pill.st1 { background: color-mix(in srgb, var(--st1) 20%, var(--surface)); color: var(--st1-ink); }
.callout { border-left: 4px solid var(--primary); background: var(--primary-soft); padding: 12px 16px; border-radius: 0 12px 12px 0; margin: 12px 0; }
.callout.warn { border-color: var(--warn); background: var(--warn-soft); }
.callout.good { border-color: var(--good); background: var(--good-soft); }

/* ---------- Lesson hero ---------- */
.kp-hero { padding: 32px 0 12px; }
.kp-hero .credit { font-family: var(--font-head); color: var(--muted); font-size: .95rem; margin-top: -4px; }
.kp-hero .meta { margin-top: 10px; }

/* ---------- แถบเส้นทางการเรียน 7 ขั้น (KP.journey) ---------- */
.kp-journey { background: var(--surface); border-bottom: 1px solid var(--line); }
.kp-jrow { display: flex; align-items: center; gap: 8px 12px; flex-wrap: wrap; padding-top: 8px; padding-bottom: 8px; }
.kp-jlabel { font: 500 .85rem var(--font-head); white-space: nowrap; }
.kp-jsteps { list-style: none; margin: 0; padding: 2px; display: flex; gap: 4px; flex: 1 1 320px; min-width: 0; overflow-x: auto; scrollbar-width: none; }
.kp-jsteps::-webkit-scrollbar { display: none; }
.kp-jstep { display: inline-flex; align-items: center; gap: 6px; min-height: 44px; padding: 4px 10px 4px 4px; border-radius: 999px; border: 2px solid transparent; color: var(--muted); text-decoration: none; white-space: nowrap; font: 500 .82rem var(--font-head); }
.kp-jstep .d { width: 32px; height: 32px; border-radius: 50%; display: grid; place-items: center; background: var(--bg-soft); color: var(--ink); font-size: .95rem; flex: none; }
.kp-jstep.done .d { background: var(--good-soft); color: var(--ink); font-weight: 700; }
.kp-jstep.cur .d { box-shadow: 0 0 0 2px var(--primary); }
.kp-jstep.here { border-color: var(--primary); background: var(--primary-soft); color: var(--ink); }
.kp-jstep.lock { opacity: .85; }
.kp-jstep:hover { color: var(--ink); }
.kp-jnext { white-space: nowrap; }
.kp-jneed { white-space: nowrap; }
/* จอแคบ: แสดงชื่อเฉพาะขั้นที่อยู่ เหลือขั้นอื่นเป็นวงกลม */
@media (max-width: 640px) { .kp-jstep:not(.here) .t { display: none; } .kp-jstep:not(.here) { padding-right: 4px; } .kp-jlabel { display: none; } .kp-jneed { white-space: normal; } }
@media print { .kp-journey { display: none !important; } }

/* ---------- สถานี (Station nav + sections) ---------- */
.kp-stations {
  position: sticky; top: 60px; z-index: 40; background: var(--bg);
  padding: 10px 0; border-bottom: 1px solid var(--line);
}
.kp-stations ol { list-style: none; margin: 0; padding: 0; display: flex; gap: 8px; overflow-x: auto; scrollbar-width: none; }
.kp-stations ol::-webkit-scrollbar { display: none; }
.kp-stations a {
  display: flex; align-items: center; gap: 8px; text-decoration: none; color: var(--muted);
  font: 500 .9rem var(--font-head); padding: 6px 12px 6px 6px; border-radius: 999px;
  border: 1px solid var(--line); background: var(--surface); white-space: nowrap;
}
.kp-stations a .n { width: 28px; height: 28px; border-radius: 50%; display: grid; place-items: center; background: color-mix(in srgb, var(--c, var(--primary)) 22%, var(--surface)); color: color-mix(in srgb, var(--c, var(--primary)) 45%, var(--ink)); border: 2px solid var(--c, var(--primary)); font-size: .85rem; font-weight: 600; }
.kp-stations a.active { color: var(--ink); border-color: var(--c); box-shadow: 0 0 0 2px color-mix(in srgb, var(--c) 25%, transparent); }
.kp-stations a.done .n::after { content: "✓"; }
.kp-stations a.done .n span { display: none; }

.station { padding: 36px 0 12px; scroll-margin-top: 130px; }
.station-head { display: flex; align-items: center; gap: 14px; margin-bottom: 16px; }
.station-head .badge {
  width: 52px; height: 52px; flex: none; border-radius: 16px; display: grid; place-items: center;
  font: 600 1.4rem var(--font-head); color: color-mix(in srgb, var(--c, var(--primary)) 45%, var(--ink)); background: color-mix(in srgb, var(--c, var(--primary)) 22%, var(--surface)); border: 2px solid var(--c, var(--primary));
  box-shadow: 0 8px 20px color-mix(in srgb, var(--c) 35%, transparent);
}
.station-head h2 { margin: 0; }
.station-head p { margin: 0; color: var(--muted); }
.station-done { margin-top: 14px; display: flex; justify-content: flex-end; }

/* ---------- Teacher-only / Student-only ---------- */
body:not([data-mode="teacher"]) .teacher-only, body:not([data-mode="teacher"]) .teacher-note { display: none !important; }
body[data-mode="teacher"] .student-only { display: none !important; }
.teacher-note {
  border: 2px dashed var(--warn); background: var(--warn-soft); border-radius: 14px; padding: 12px 16px; margin: 12px 0;
}
.teacher-note[data-tn]:empty { display: none !important; } /* เนื้อหาครูที่ยังไม่ได้โหลดจากเว็บหลัก (tools/deploy.cjs) */
.teacher-note::before { content: "👩‍🏫 บันทึกสำหรับครู"; display: block; font: 600 .85rem var(--font-head); color: var(--warn); margin-bottom: 4px; }

/* ---------- Flip cards ---------- */
.flip-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 16px; }
.flip { perspective: 1000px; min-height: 190px; cursor: pointer; border: 0; padding: 0; background: none; font: inherit; color: inherit; text-align: left; }
.flip .inner { position: relative; width: 100%; height: 100%; min-height: 190px; transition: transform .6s; transform-style: preserve-3d; }
.flip.flipped .inner { transform: rotateY(180deg); }
.flip .face {
  position: absolute; inset: 0; backface-visibility: hidden; -webkit-backface-visibility: hidden;
  border-radius: var(--radius); padding: 20px; display: flex; flex-direction: column; justify-content: center;
  border: 1px solid var(--line); box-shadow: var(--shadow);
}
.flip .front { background: linear-gradient(135deg, var(--primary-soft), var(--surface)); }
.flip .front::after { content: "แตะเพื่อพลิก ↻"; position: absolute; right: 14px; bottom: 10px; font-size: .78rem; color: var(--muted); font-family: var(--font-head); }
.flip .back { background: var(--surface); transform: rotateY(180deg); }
.flip .face h4 { font-size: 1.05rem; margin-bottom: 6px; }
@media (prefers-reduced-motion: reduce) {
  .flip .inner { transition: none; }
}

/* ---------- Predict (ทายก่อนทดลอง) ---------- */
.predict { border: 2px solid var(--st1); }
.predict .q { font: 500 1.1rem var(--font-head); margin-bottom: 12px; }
.choices { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 10px; }
.choice {
  appearance: none; text-align: left; border: 2px solid var(--line); background: var(--surface); color: var(--ink);
  font: inherit; padding: 12px 14px; border-radius: 14px; cursor: pointer; min-height: 52px;
  display: flex; gap: 10px; align-items: flex-start; transition: border-color .2s, background .2s;
}
.choice .key { flex: none; width: 28px; height: 28px; border-radius: 8px; display: grid; place-items: center; background: var(--bg-soft); font: 600 .85rem var(--font-head); }
.choice:hover:not([disabled]) { border-color: var(--primary); }
.choice.picked { border-color: var(--primary); background: var(--primary-soft); }
.choice.correct { border-color: var(--good); background: var(--good-soft); }
.choice.correct .key { background: var(--good); color: var(--surface); }
.choice.wrong { border-color: var(--bad); background: var(--bad-soft); }
.choice.wrong .key { background: var(--bad); color: var(--surface); }
.choice.wrong .key::before { content: "✕"; }
.choice.wrong .key span { display: none; }
.choice[disabled] { cursor: default; }
.shake { animation: kp-shake .4s; }
@keyframes kp-shake { 0%,100% { transform: translateX(0); } 20% { transform: translateX(-8px); } 40% { transform: translateX(8px); } 60% { transform: translateX(-5px); } 80% { transform: translateX(5px); } }
@media (prefers-reduced-motion: reduce) { .shake { animation: none; } }
.feedback { margin-top: 12px; border-radius: 12px; padding: 12px 14px; display: none; }
.feedback.show { display: block; }
.feedback.good { background: var(--good-soft); }
.feedback.bad { background: var(--bad-soft); }
.feedback.info { background: var(--primary-soft); }

/* ---------- Quiz ---------- */
.quiz-top { display: flex; justify-content: space-between; align-items: center; gap: 10px; margin-bottom: 12px; flex-wrap: wrap; }
.quiz-dots { display: flex; gap: 6px; }
.quiz-dots i { width: 12px; height: 12px; border-radius: 50%; background: var(--line); }
.quiz-dots i.now { background: var(--primary); }
.quiz-dots i.ok { background: var(--good); }
.quiz-dots i.retry { background: var(--warn); }
.quiz-q { font: 500 1.15rem var(--font-head); margin-bottom: 14px; }
.quiz-result { text-align: center; padding: 20px; }
.quiz-result .score { font: 700 3rem var(--font-head); color: var(--primary); }

/* ---------- Simulation lab ---------- */
.lab { display: grid; grid-template-columns: minmax(0, 1fr) 320px; gap: 16px; align-items: start; }
@media (max-width: 960px) { .lab { grid-template-columns: 1fr; } }
.sim-stage { background: var(--sim-bg); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; position: relative; }
.sim-stage canvas { display: block; width: 100%; height: auto; touch-action: none; }
.sim-overlay { position: absolute; left: 12px; top: 10px; font: 500 .85rem var(--font-head); color: var(--muted); pointer-events: none; }
.controls { display: grid; gap: 14px; }
.ctrl label { display: flex; justify-content: space-between; font: 500 .92rem var(--font-head); margin-bottom: 4px; }
.ctrl output { color: var(--primary); font-variant-numeric: tabular-nums; }
input[type="range"] { width: 100%; accent-color: var(--primary); height: 28px; cursor: pointer; }
.readouts { display: grid; grid-template-columns: repeat(2, 1fr); gap: 8px; }
.readout { background: var(--surface-2); border: 1px solid var(--line); border-radius: 12px; padding: 8px 10px; }
.readout b { display: block; font: 600 1.05rem var(--font-head); font-variant-numeric: tabular-nums; }
.readout span { font-size: .78rem; color: var(--muted); }
.seg { display: flex; flex-wrap: wrap; gap: 6px; }
.seg button { border: 1px solid var(--line); background: var(--surface); color: var(--ink); border-radius: 10px; padding: 6px 10px; font: 500 .85rem var(--font-head); cursor: pointer; min-height: 38px; }
.seg button[aria-pressed="true"] { background: var(--primary); color: var(--primary-ink); border-color: var(--primary); }
.check { display: flex; gap: 8px; align-items: center; font-size: .92rem; cursor: pointer; }
.check input { width: 18px; height: 18px; accent-color: var(--primary); }

/* ---------- Worksheet / table ---------- */
table.data { width: 100%; border-collapse: collapse; font-variant-numeric: tabular-nums; }
table.data th, table.data td { border: 1px solid var(--line); padding: 8px 10px; text-align: center; }
table.data th { background: var(--bg-soft); font: 500 .9rem var(--font-head); }
table.data input { width: 100%; min-width: 3.6em; border: 0; background: transparent; color: var(--ink); font: inherit; text-align: center; padding: 4px; }
.table-scroll { overflow-x: auto; }
textarea, input.text, input.num {
  width: 100%; border: 1.5px solid var(--line); border-radius: 12px; padding: 10px 12px;
  font: inherit; background: var(--surface); color: var(--ink);
}
textarea { min-height: 84px; resize: vertical; }
textarea:focus, input.text:focus, input.num:focus { border-color: var(--primary); outline: none; box-shadow: 0 0 0 3px var(--primary-soft); }

/* ---------- Exercises ---------- */
.ex { border-left: 5px solid var(--st5); }
.ex + .ex { margin-top: 14px; }
.ex .lvl { font: 500 .78rem var(--font-head); }
.ex .answer-row { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; margin-top: 10px; }
.ex .answer-row input { max-width: 200px; }
.ex .unit { font-family: var(--font-head); color: var(--muted); }
.ex .steps { margin-top: 12px; display: grid; gap: 8px; }
.ex .step { background: var(--surface-2); border: 1px solid var(--line); border-radius: 12px; padding: 10px 14px; animation: kp-in .35s ease; }
.ex .step b { font-family: var(--font-head); color: var(--st5-ink); margin-right: 6px; }
.ex.solved { border-left-color: var(--good); }
@keyframes kp-in { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }
@media (prefers-reduced-motion: reduce) { .ex .step { animation: none; } }

/* ---------- Toast / overlay / modal ---------- */
.kp-toasts { position: fixed; right: 16px; bottom: 16px; z-index: 300; display: grid; gap: 8px; }
.kp-toast { background: var(--ink); color: var(--bg); padding: 10px 16px; border-radius: 12px; font: 500 .92rem var(--font-head); box-shadow: var(--shadow-lg); animation: kp-in .3s ease; max-width: 320px; }
.kp-flash { position: fixed; inset: 0; background: rgba(229, 72, 77, .18); pointer-events: none; z-index: 250; opacity: 0; }
.kp-flash.go { animation: kp-flash .35s ease; }
@keyframes kp-flash { 0% { opacity: 0; } 40% { opacity: 1; } 100% { opacity: 0; } }
.kp-confetti { position: fixed; inset: 0; pointer-events: none; z-index: 260; }
.kp-modal { position: fixed; inset: 0; z-index: 400; background: rgba(10, 12, 30, .55); display: none; place-items: center; padding: 16px; }
.kp-modal.open { display: grid; }
.kp-modal .box { background: var(--surface); color: var(--ink); border-radius: 22px; padding: 24px; width: min(560px, 100%); max-height: 90vh; overflow: auto; box-shadow: var(--shadow-lg); }
.kp-modal .box h3 { display: flex; justify-content: space-between; align-items: center; }
.timer-display { font: 700 clamp(3rem, 14vw, 6rem) var(--font-head); text-align: center; font-variant-numeric: tabular-nums; }
.picker-display { font: 700 clamp(2rem, 10vw, 4.5rem) var(--font-head); text-align: center; min-height: 1.4em; color: var(--primary); }

/* ---------- Footer ---------- */
.kp-footer { padding: 40px 0 60px; color: var(--muted); font-size: .9rem; text-align: center; }

/* ---------- Print (ใบงาน A4) ---------- */
@media print {
  .kp-header, .kp-stations, .kp-footer, .kp-watermark, .btn, .no-print, .kp-toasts { display: none !important; }
  body { background: #fff; color: #000; font-size: 13pt; }
  .card { box-shadow: none; border-color: #bbb; break-inside: avoid; }
  .station { padding: 8px 0; }
  body.kp-printing .station:not(.print-me), body.kp-printing .kp-hero { display: none; }
  @page { size: A4; margin: 14mm; }
}

/* ---------- แถบเครื่องมือครู (assets/js/kp-teacher.js) ---------- */
body.kt-docked { padding-bottom: 76px; }
body.kt-docked .kp-toasts { bottom: 84px; }
.kt-dock { position: fixed; left: 50%; bottom: 10px; transform: translateX(-50%); z-index: 280; display: flex; gap: 6px; align-items: center;
  padding: 6px; max-width: calc(100% - 16px); background: var(--surface); color: var(--ink); border: 1px solid var(--line); border-radius: 16px; box-shadow: var(--shadow-lg); }
.kt-dock .btn { min-height: 44px; padding: 6px 10px; white-space: nowrap; }
.kt-dock .kt-clock { font: 600 1rem var(--font-head); font-variant-numeric: tabular-nums; }
.kt-dock .kt-clock small { display: block; font: 500 .75rem var(--font-body); color: var(--muted); line-height: 1.1; }
.kt-dock .kt-clock.over b { color: var(--bad); }
.kt-dock .kt-room { font: 600 .8rem var(--font-head); padding: 4px 10px; border-radius: 999px; background: var(--primary-soft); color: var(--ink); white-space: nowrap; }
.kt-dock.min > :not(.kt-toggle) { display: none; }
@media (max-width: 700px) { .kt-dock .kt-lbl { display: none; } .kt-dock .kt-clock small { display: none; } }
body.kt-hide-notes .teacher-note { display: none !important; }
.kt-notice { font-size: .85rem; color: var(--muted); padding: 0 6px; max-width: 220px; }
.kt-blackout { position: fixed; inset: 0; z-index: 500; background: var(--blackout); color: var(--blackout-ink); display: grid; place-items: center; text-align: center; cursor: pointer;
  font: 500 1rem var(--font-head); animation: kt-fade .4s ease; }
@keyframes kt-fade { from { opacity: 0; } to { opacity: 1; } }
@media (prefers-reduced-motion: reduce) { .kt-blackout { animation: none; } }
.kt-plan { display: grid; gap: 6px; margin: 10px 0; }
.kt-seg { display: grid; grid-template-columns: 1fr auto; gap: 8px; align-items: center; padding: 8px 12px; border-radius: 12px; border: 1px solid var(--line); background: var(--surface-2); }
.kt-seg.now { border: 2px solid var(--primary); background: var(--primary-soft); }
.kt-seg.done { color: var(--muted); }
.kt-seg .kt-min { display: flex; gap: 6px; align-items: center; font-variant-numeric: tabular-nums; }
.kt-seg .kt-min .btn { min-height: 44px; min-width: 44px; padding: 4px; justify-content: center; }
.kt-sum h4 { margin: 14px 0 6px; }
.kt-sum textarea { width: 100%; min-height: 220px; font: 400 1rem/1.6 var(--font-body); color: var(--ink); background: var(--surface-2); border: 1px solid var(--line); border-radius: 12px; padding: 10px 12px; }
.kt-sum table { width: 100%; border-collapse: collapse; font-size: .92rem; }
.kt-sum td, .kt-sum th { padding: 6px 8px; border-bottom: 1px solid var(--line); text-align: left; }
.kt-sum .kt-code { user-select: all; word-break: break-all; font: 400 .8rem/1.4 monospace; background: var(--bg-soft); padding: 8px 10px; border-radius: 10px; }
@media print { .kt-dock, .kt-blackout { display: none !important; } }