/* ============ tokens: light is the base ============ */
:root{
  --ground:#EAEEF3; --surface:#FFFFFF; --surface-2:#F3F6F9; --sunken:#E2E8EF;
  --ink:#111820; --ink-2:#414F5F; --ink-3:#6C7C8D; --line:#CFD8E2; --line-2:#E4EAF1;
  --addr:#0F7A4B; --addr-soft:#DFF2E8;
  --data:#5B3BB8; --data-soft:#E9E3FA;
  --ctrl:#B32D2D; --ctrl-soft:#FBE3E1;
  --cs:#10609F;   --cs-soft:#DEEAF7;
  --boot:#9A6414; --boot-soft:#F8ECD5;
  --teal:#0F7A8A;
  --ok:#0F7A4B; --warn:#9A6414; --bad:#B32D2D;
  --shadow:0 1px 2px rgba(17,24,32,.06), 0 8px 24px -12px rgba(17,24,32,.18);
  --shadow-lift:0 2px 4px rgba(17,24,32,.08), 0 18px 40px -18px rgba(17,24,32,.30);
  --grid-line:rgba(16,96,159,.07);
}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    --ground:#0C1218; --surface:#141C25; --surface-2:#18222D; --sunken:#0F171F;
    --ink:#E3EAF1; --ink-2:#A9B8C7; --ink-3:#7A8B9C; --line:#28343F; --line-2:#1E2A35;
    --addr:#46CC8C; --addr-soft:#0F2A20;
    --data:#AE92F7; --data-soft:#221A3A;
    --ctrl:#FF837A; --ctrl-soft:#341A1B;
    --cs:#5FB4F2;   --cs-soft:#0F2537;
    --boot:#EAB459; --boot-soft:#2E2312;
    --teal:#4FC3D9;
    --ok:#46CC8C; --warn:#EAB459; --bad:#FF837A;
    --shadow:0 1px 2px rgba(0,0,0,.4), 0 10px 30px -14px rgba(0,0,0,.7);
    --shadow-lift:0 2px 6px rgba(0,0,0,.5), 0 22px 50px -20px rgba(0,0,0,.8);
    --grid-line:rgba(95,180,242,.07);
  }
}
:root[data-theme="dark"]{
  --ground:#0C1218; --surface:#141C25; --surface-2:#18222D; --sunken:#0F171F;
  --ink:#E3EAF1; --ink-2:#A9B8C7; --ink-3:#7A8B9C; --line:#28343F; --line-2:#1E2A35;
  --addr:#46CC8C; --addr-soft:#0F2A20;
  --data:#AE92F7; --data-soft:#221A3A;
  --ctrl:#FF837A; --ctrl-soft:#341A1B;
  --cs:#5FB4F2;   --cs-soft:#0F2537;
  --boot:#EAB459; --boot-soft:#2E2312;
  --teal:#4FC3D9;
  --ok:#46CC8C; --warn:#EAB459; --bad:#FF837A;
  --shadow:0 1px 2px rgba(0,0,0,.4), 0 10px 30px -14px rgba(0,0,0,.7);
  --shadow-lift:0 2px 6px rgba(0,0,0,.5), 0 22px 50px -20px rgba(0,0,0,.8);
  --grid-line:rgba(95,180,242,.07);
}

*{box-sizing:border-box}
body{
  margin:0; background:var(--ground); color:var(--ink);
  font-family:'IBM Plex Sans Thai','Noto Sans Thai',system-ui,sans-serif;
  font-size:15.5px; line-height:1.62; -webkit-font-smoothing:antialiased;
  background-image:linear-gradient(var(--grid-line) 1px,transparent 1px),linear-gradient(90deg,var(--grid-line) 1px,transparent 1px);
  background-size:32px 32px;
}
h1,h2,h3,h4,.disp{font-family:'Chakra Petch','IBM Plex Sans Thai',system-ui,sans-serif;font-weight:600;text-wrap:balance;letter-spacing:.01em}
code,kbd,.mono{font-family:'IBM Plex Mono',ui-monospace,monospace;font-variant-ligatures:none}
a{color:var(--cs)}
:focus-visible{outline:2px solid var(--cs);outline-offset:3px;border-radius:4px}

/* ============ shell ============ */
.wrap{max-width:1180px;margin:0 auto;padding:0 20px 96px}
.topbar{position:sticky;top:0;z-index:50;-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);
  background:color-mix(in srgb,var(--ground) 86%,transparent);border-bottom:1px solid var(--line)}
.topbar-in{max-width:1180px;margin:0 auto;padding:8px 20px;display:flex;align-items:center;gap:12px}
.brand{display:flex;align-items:center;gap:9px;font-family:'Chakra Petch',sans-serif;font-weight:700;font-size:15px;white-space:nowrap;color:var(--ink);text-decoration:none;flex:none}
.brand .dot{width:9px;height:9px;border-radius:50%;background:var(--addr);box-shadow:0 0 0 3px color-mix(in srgb,var(--addr) 22%,transparent)}
.brand:hover{color:var(--cs)}
.tabs{display:flex;align-items:center;gap:6px;flex:1;min-width:0}
.dd{position:relative}
.tab-btn{display:inline-flex;align-items:center;gap:7px;border:1px solid transparent;background:none;color:var(--ink-2);font-family:'Chakra Petch','IBM Plex Sans Thai',sans-serif;font-weight:600;font-size:14px;line-height:1.2;padding:6px 10px 6px 12px;border-radius:9px;cursor:pointer;white-space:nowrap;transition:background .15s,color .15s,border-color .15s}
.tab-btn:hover{background:var(--surface-2);color:var(--ink)}
.dd.here>.tab-btn{color:var(--ink);background:var(--surface);border-color:var(--line);box-shadow:inset 0 -2px 0 var(--cs)}
.dd.open>.tab-btn{background:var(--surface);border-color:var(--cs);color:var(--ink)}
.tab-btn .cur{font-family:'IBM Plex Sans Thai',sans-serif;font-weight:500;font-size:12.5px;color:var(--cs);max-width:190px;overflow:hidden;text-overflow:ellipsis}
.tab-btn .cur:empty{display:none}
.tab-btn .cur::before{content:'·';margin-right:6px;color:var(--ink-3)}
.tab-btn .chev{width:12px;height:12px;flex:none;transition:transform .2s ease;color:var(--ink-3)}
.dd.open>.tab-btn .chev{transform:rotate(180deg)}
.tab-btn .soon{font-family:'Chakra Petch',sans-serif;font-size:10.5px;font-weight:700;letter-spacing:.06em;color:var(--boot);background:var(--boot-soft);border-radius:20px;padding:1px 7px}
.menu{position:absolute;top:calc(100% + 8px);left:0;min-width:270px;background:var(--surface);border:1px solid var(--line);border-radius:14px;box-shadow:var(--shadow-lift);padding:8px;display:none;z-index:60}
.dd.open>.menu{display:block;animation:menuIn .16s ease-out}
.menu.menu-wide{min-width:620px}
.dd.open>.menu.menu-wide{display:grid;grid-template-columns:1fr 1fr;gap:4px 10px}
@keyframes menuIn{from{opacity:0;transform:translateY(-4px)}to{opacity:1;transform:none}}
.menu-h{font-family:'Chakra Petch',sans-serif;font-size:11.5px;font-weight:700;letter-spacing:.12em;text-transform:uppercase;color:var(--ink-3);padding:7px 10px 5px;display:flex;align-items:center;gap:8px}
.menu-h a{padding:0;margin-left:auto;font-size:11.5px;letter-spacing:.04em;text-transform:none;color:var(--cs);background:none}
.menu a{display:flex;align-items:baseline;gap:9px;padding:7px 10px;border-radius:8px;color:var(--ink-2);text-decoration:none;font-size:14px;line-height:1.35;transition:background .12s,color .12s}
.menu a:hover,.menu a:focus-visible{background:var(--surface-2);color:var(--ink)}
.menu a.on{background:var(--cs-soft);color:var(--cs);font-weight:600}
.menu a .n{font-family:'IBM Plex Mono',monospace;font-size:12px;color:var(--ink-3);min-width:2.1em;flex:none}
.menu a.on .n{color:var(--cs)}
.menu a small{display:block;font-size:12px;color:var(--ink-3);font-weight:400}
.menu-sep{height:1px;background:var(--line-2);margin:6px 4px}
.menu-col{min-width:0}
.themebtn{border:1px solid var(--line);background:var(--surface);color:var(--ink-2);border-radius:8px;width:34px;height:32px;padding:0;cursor:pointer;display:grid;place-items:center;flex:none;margin-left:auto}
.themebtn:hover{color:var(--ink);border-color:var(--ink-3)}
.themebtn svg{width:16px;height:16px}
.progress{height:2px;background:var(--cs);width:0;transition:width .1s linear}
@media (max-width:760px){
  .topbar-in{padding:8px 12px;gap:8px}
  .brand .full{display:none}
  .tabs{gap:2px}
  .dd{position:static}
  .tab-btn{padding:6px 8px 6px 10px;font-size:13.5px}
  .tab-btn .cur{display:none}
  .menu,.menu.menu-wide{left:8px;right:8px;min-width:0;top:calc(100% + 1px);max-height:calc(100vh - 64px);max-height:calc(100dvh - 64px);overflow:auto;overscroll-behavior:contain}
  .dd.open>.menu.menu-wide{grid-template-columns:1fr}
}
.banner{display:flex;gap:14px;align-items:center;flex-wrap:wrap;background:var(--surface);border:1px solid var(--line);border-left:4px solid var(--ctrl);border-radius:12px;padding:12px 16px;margin:22px 0 0;box-shadow:var(--shadow)}
.banner b{font-family:'Chakra Petch',sans-serif}
.banner p{margin:0;flex:1;min-width:220px;font-size:14.5px;color:var(--ink-2)}
.banner .btn{text-decoration:none}

/* ============ hero ============ */
.hero{padding:64px 0 40px;position:relative}
.eyebrow{font-family:'Chakra Petch',sans-serif;font-size:12px;font-weight:600;letter-spacing:.16em;text-transform:uppercase;color:var(--cs)}
.hero h1{font-size:clamp(34px,6vw,58px);line-height:1.06;margin:12px 0 0;font-weight:700}
.hero h1 em{font-style:normal;color:var(--addr)}
.hero p.lead{font-size:17px;color:var(--ink-2);max-width:62ch;margin:16px 0 0}
.stats{display:flex;flex-wrap:wrap;gap:10px;margin-top:26px}
html{overflow-x:hidden}
.stat{background:var(--surface);border:1px solid var(--line);border-radius:11px;padding:10px 15px;box-shadow:var(--shadow)}
.stat b{display:block;font-family:'Chakra Petch',sans-serif;font-size:23px;line-height:1.1}
.stat span{font-size:12.5px;color:var(--ink-3)}

/* ============ sections & cards ============ */
section{scroll-margin-top:64px;padding-top:52px}
.sechead{display:flex;align-items:flex-end;gap:14px;flex-wrap:wrap;border-bottom:2px solid var(--line);padding-bottom:12px;margin-bottom:22px}
.sechead h2{font-size:27px;margin:0;flex:1;min-width:220px}
.qtag{font-family:'Chakra Petch',sans-serif;font-size:12px;font-weight:700;letter-spacing:.1em;padding:3px 10px;border-radius:5px;text-transform:uppercase}
.card{background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:20px 22px;box-shadow:var(--shadow);margin-bottom:16px}
.card h3{font-size:18px;margin:0 0 10px}
.card h4{font-size:15px;margin:16px 0 6px;color:var(--ink-2)}
.card > :last-child{margin-bottom:0}
.grid{display:grid;gap:16px}
.grid>*{min-width:0}
.card,.lab{min-width:0}
@media(min-width:840px){.g2{grid-template-columns:1fr 1fr}.g3{grid-template-columns:repeat(3,1fr)}}

.tint{border-left:4px solid var(--tint,var(--cs));background:var(--tintbg,var(--cs-soft));border-radius:10px;padding:12px 15px;margin:12px 0}
.tint .lbl{display:block;font-family:'Chakra Petch',sans-serif;font-weight:700;font-size:13px;letter-spacing:.03em;color:var(--tint,var(--cs));margin-bottom:3px}
.t-ans{--tint:var(--addr);--tintbg:var(--addr-soft)}
.t-why{--tint:var(--cs);--tintbg:var(--cs-soft)}
.t-flip{--tint:var(--boot);--tintbg:var(--boot-soft)}
.t-trap{--tint:var(--ctrl);--tintbg:var(--ctrl-soft)}
.t-tip{--tint:var(--data);--tintbg:var(--data-soft)}

table{border-collapse:collapse;width:100%;font-size:14px}
.tablewrap{overflow-x:auto;margin:12px 0;border:1px solid var(--line);border-radius:11px}
.tablewrap table{font-variant-numeric:tabular-nums}
th,td{padding:7px 11px;text-align:left;border-bottom:1px solid var(--line-2);vertical-align:top}
thead th{background:var(--surface-2);font-family:'Chakra Petch',sans-serif;font-size:12.5px;letter-spacing:.03em;font-weight:700;color:var(--ink-2);white-space:nowrap}
tbody tr:last-child td{border-bottom:0}
tbody tr:hover td{background:var(--surface-2)}
td.c,th.c{text-align:center}

code{background:var(--sunken);border:1px solid var(--line-2);padding:.5px 5px;border-radius:5px;font-size:.9em}
pre{background:var(--sunken);border:1px solid var(--line);border-radius:11px;padding:14px 16px;overflow-x:auto;font-family:'IBM Plex Mono',monospace;font-size:13.5px;line-height:1.62;margin:12px 0}
pre code{background:none;border:0;padding:0;font-size:inherit}
.cm{color:var(--ink-3);font-style:italic}
.kw{color:var(--data);font-weight:500}
.hx{color:var(--boot);font-weight:500}
ul,ol{padding-left:1.25em;margin:8px 0}
li{margin:3px 0}
.hl{background:color-mix(in srgb,var(--boot) 26%,transparent);border-radius:3px;padding:0 3px}

/* ============ widgets ============ */
.lab{background:var(--surface);border:1px solid var(--line);border-radius:14px;overflow:hidden;box-shadow:var(--shadow-lift);margin:18px 0}
.lab-head{display:flex;align-items:center;gap:10px;padding:11px 16px;background:var(--surface-2);border-bottom:1px solid var(--line)}
.lab-head .k{font-family:'Chakra Petch',sans-serif;font-size:12px;font-weight:700;letter-spacing:.12em;text-transform:uppercase;color:var(--ink-3)}
.lab-head .t{font-family:'Chakra Petch',sans-serif;font-weight:600;font-size:15px}
.lab-body{padding:18px}
.seg{display:inline-flex;background:var(--sunken);border:1px solid var(--line);border-radius:10px;padding:3px;gap:3px;flex-wrap:wrap}
.seg button{border:0;background:none;color:var(--ink-2);font:inherit;font-size:13.5px;padding:6px 13px;border-radius:7px;cursor:pointer;transition:background .16s,color .16s;font-family:'Chakra Petch',sans-serif;font-weight:600}
.seg button:hover{color:var(--ink)}
.seg button[aria-pressed="true"]{background:var(--cs);color:#fff}
.field{display:flex;flex-direction:column;gap:5px}
.field label{font-size:12.5px;font-family:'Chakra Petch',sans-serif;font-weight:600;letter-spacing:.06em;text-transform:uppercase;color:var(--ink-3)}
input[type=text],select{font-family:'IBM Plex Mono',monospace;font-size:14.5px;background:var(--sunken);color:var(--ink);border:1px solid var(--line);border-radius:9px;padding:8px 11px;width:100%}
input[type=text]:focus,select:focus{border-color:var(--cs)}
.row{display:flex;gap:12px;flex-wrap:wrap;align-items:flex-end}
.readout{font-family:'IBM Plex Mono',monospace;font-size:17px;font-weight:500;letter-spacing:.02em}
.pill{display:inline-block;font-family:'Chakra Petch',sans-serif;font-size:12px;font-weight:700;letter-spacing:.06em;padding:2px 9px;border-radius:20px;border:1px solid}
.p-ok{color:var(--ok);border-color:var(--ok);background:var(--addr-soft)}
.p-warn{color:var(--warn);border-color:var(--warn);background:var(--boot-soft)}
.p-bad{color:var(--bad);border-color:var(--bad);background:var(--ctrl-soft)}
.p-cs{color:var(--cs);border-color:var(--cs);background:var(--cs-soft)}
.note{font-size:13.5px;color:var(--ink-2);margin-top:12px}
svg{display:block;max-width:100%;height:auto}
.dash{stroke-dasharray:5 7;animation:flow 1.1s linear infinite}
@keyframes flow{to{stroke-dashoffset:-24}}
.pulse{animation:pulse 1.4s ease-in-out infinite}
@keyframes pulse{0%,100%{opacity:.35}50%{opacity:1}}
.shake{animation:shake .42s cubic-bezier(.36,.07,.19,.97)}
@keyframes shake{10%,90%{transform:translateX(-1.5px)}20%,80%{transform:translateX(3px)}30%,50%,70%{transform:translateX(-5px)}40%,60%{transform:translateX(5px)}}
.flash{animation:flash .6s ease-out}
@keyframes flash{from{background:color-mix(in srgb,var(--boot) 45%,transparent)}to{background:transparent}}
.js .reveal{opacity:0;transform:translateY(14px);transition:opacity .5s ease,transform .5s ease}
.js .reveal.in{opacity:1;transform:none}
@media (prefers-reduced-motion: reduce){
  *,*::before,*::after{animation-duration:.001ms !important;animation-iteration-count:1 !important;transition-duration:.001ms !important}
  .js .reveal{opacity:1;transform:none}
}

/* bit field strip */
.bits{display:flex;border-radius:9px;overflow:hidden;border:1px solid var(--line);margin:10px 0;font-family:'IBM Plex Mono',monospace}
.bits div{padding:7px 4px;text-align:center;color:#fff;font-size:12.5px;line-height:1.3;min-width:0}
.bits div small{display:block;font-size:10px;opacity:.85;font-family:'Chakra Petch',sans-serif;letter-spacing:.06em}
.b-op{background:#B32D2D}.b-rs{background:#10609F}.b-rt{background:#0F7A4B}
.b-rd{background:#5B3BB8}.b-sh{background:#7A5C1F}.b-fn{background:#9A6414}.b-im{background:#455A6B}

/* memory map bar */
.mapbar{display:flex;height:38px;border-radius:9px;overflow:hidden;border:1px solid var(--line);margin:12px 0;position:relative}
.mapbar div{display:grid;place-items:center;min-width:0;overflow:hidden;white-space:nowrap;text-overflow:ellipsis;font-family:'Chakra Petch',sans-serif;font-size:11.5px;font-weight:700;color:#fff;border-right:1px solid rgba(255,255,255,.28);transition:filter .2s}
.mapbar div:last-child{border-right:0}
.mapbar div.dim{filter:saturate(.15) opacity(.42)}
.marker{position:absolute;top:-7px;bottom:-7px;width:3px;background:var(--ink);border-radius:2px;box-shadow:0 0 0 1.5px var(--surface);z-index:3;transition:left .28s cubic-bezier(.2,.9,.3,1)}
.marker::before{content:'';position:absolute;top:-5px;left:-4px;width:11px;height:11px;background:var(--ink);border:1.5px solid var(--surface);border-radius:50%}

/* device chips for arbiter */
.devrow{display:flex;gap:12px;flex-wrap:wrap;margin:14px 0}
.dev{flex:1;min-width:120px;border:2px solid var(--line);border-radius:12px;padding:12px;text-align:center;cursor:pointer;background:var(--surface-2);transition:border-color .2s,background .2s,transform .18s}
.dev:hover{transform:translateY(-2px)}
.dev.grant{border-color:var(--addr);background:var(--addr-soft)}
.dev.conflict{border-color:var(--ctrl);background:var(--ctrl-soft)}
.dev .nm{font-family:'Chakra Petch',sans-serif;font-size:19px;font-weight:700}
.dev .st{font-size:12px;color:var(--ink-2);margin-top:3px}

.stepper{display:flex;gap:8px;flex-wrap:wrap;align-items:center;margin-bottom:14px}
.btn{font-family:'Chakra Petch',sans-serif;font-weight:600;font-size:13.5px;border:1px solid var(--line);background:var(--surface-2);color:var(--ink);border-radius:9px;padding:7px 14px;cursor:pointer;transition:background .16s,border-color .16s}
.btn:hover{border-color:var(--cs);background:var(--cs-soft)}
.btn.primary{background:var(--cs);border-color:var(--cs);color:#fff}
.btn.primary:hover{filter:brightness(1.08)}
.btn[disabled]{opacity:.4;cursor:not-allowed}
.regs{display:grid;grid-template-columns:repeat(auto-fit,minmax(128px,1fr));gap:9px;margin-top:14px}
.reg{background:var(--sunken);border:1px solid var(--line);border-radius:9px;padding:8px 11px}
.reg .n{font-family:'IBM Plex Mono',monospace;font-size:12px;color:var(--ink-3)}
.reg .v{font-family:'IBM Plex Mono',monospace;font-size:14.5px;font-weight:500}

details.flip{border:1px solid var(--line);border-radius:11px;background:var(--surface);margin-bottom:9px;overflow:hidden}
details.flip summary{cursor:pointer;padding:11px 15px;font-weight:500;list-style:none;display:flex;gap:10px;align-items:flex-start}
details.flip summary::-webkit-details-marker{display:none}
details.flip summary::before{content:'+';font-family:'IBM Plex Mono',monospace;color:var(--boot);font-weight:600;flex:none;line-height:1.5}
details.flip[open] summary::before{content:'−'}
details.flip[open] summary{background:var(--boot-soft);border-bottom:1px solid var(--line)}
details.flip .ans{padding:12px 15px 14px 34px;font-size:14.5px;color:var(--ink-2)}
details.flip .ans b,details.flip .ans strong{color:var(--ink)}


.figbox{background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:14px;box-shadow:var(--shadow);margin:18px 0}
.figbox img{display:block;width:auto;max-width:100%;height:auto;margin:0 auto;border-radius:8px;background:#fff}
.figbox figcaption{font-size:13px;color:var(--ink-3);margin-top:10px;text-align:center}
/* ---------- per-sub-question blocks ---------- */
.qhead{border-top:3px solid var(--acc,var(--cs))}
.qintro{margin:12px 0 0;font-size:14.5px;color:var(--ink-2)}
.subs-lead{display:flex;align-items:center;gap:12px;margin:26px 0 14px;font-family:'Chakra Petch',sans-serif;font-size:12px;font-weight:700;letter-spacing:.16em;text-transform:uppercase;color:var(--ink-3)}
.subs-lead .line{flex:1;height:1px;background:var(--line)}
.sub{background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:16px 18px 18px;box-shadow:var(--shadow);margin-bottom:14px;scroll-margin-top:70px}
.sub-head{display:flex;align-items:center;gap:10px;flex-wrap:wrap;margin-bottom:12px}
.sub-no{font-family:'IBM Plex Mono',monospace;font-weight:600;font-size:13.5px;color:#fff;background:var(--acc,var(--cs));border-radius:8px;padding:3px 10px;flex:none}
.sub-head h3{margin:0;font-size:17px;flex:1;min-width:170px}
.sub .scan{margin-bottom:12px}
.sub .tint:last-child{margin-bottom:0}
.sub pre{margin:8px 0 0}
.subindex{display:flex;align-items:center;gap:6px;flex-wrap:wrap;margin-top:14px;padding-top:12px;border-top:1px dashed var(--line)}
.subindex>span:first-child{font-family:'Chakra Petch',sans-serif;font-size:11.5px;font-weight:700;letter-spacing:.12em;text-transform:uppercase;color:var(--ink-3);margin-right:2px}
.subjump{font-family:'IBM Plex Mono',monospace;font-size:12.5px;text-decoration:none;color:var(--acc,var(--cs));border:1px solid var(--line);border-radius:7px;padding:2px 9px;transition:background .15s,border-color .15s,color .15s}
.subjump:hover{background:var(--acc,var(--cs));border-color:var(--acc,var(--cs));color:#fff}

.itgrid{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:9px;margin-top:14px}
.itcell{background:var(--sunken);border:1px solid var(--line);border-radius:10px;padding:9px 12px;transition:border-color .25s,background .25s}
.itcell.on{border-color:var(--ctrl);background:var(--ctrl-soft)}
.itcell .k{font-family:'Chakra Petch',sans-serif;font-size:11.5px;font-weight:700;letter-spacing:.08em;color:var(--ink-3)}
.itcell.on .k{color:var(--ctrl)}
.itcell .v{font-family:'IBM Plex Mono',monospace;font-size:14.5px;font-weight:500;margin-top:2px}

/* ---------- original exam question scans ---------- */
.paper{border:1px solid var(--line);border-radius:14px;background:var(--surface);box-shadow:var(--shadow);margin:0 0 18px;overflow:hidden}
.paper>summary{cursor:pointer;list-style:none;display:flex;align-items:center;gap:10px;padding:11px 16px;background:var(--surface-2);border-bottom:1px solid var(--line);font-family:'Chakra Petch',sans-serif;font-weight:600;font-size:15px}
.paper>summary::-webkit-details-marker{display:none}
.paper>summary::before{content:'\25BE';color:var(--ink-3);font-size:12px;line-height:1;transition:transform .2s}
.paper:not([open])>summary{border-bottom:0}
.paper:not([open])>summary::before{transform:rotate(-90deg)}
.paper>summary .k{font-family:'Chakra Petch',sans-serif;font-size:11.5px;font-weight:700;letter-spacing:.12em;text-transform:uppercase;color:var(--ink-3)}
.paper>summary .hint{margin-left:auto;font-family:'IBM Plex Sans Thai',sans-serif;font-weight:400;font-size:12.5px;color:var(--ink-3)}
.paper-body{padding:14px;background:var(--sunken)}
.scan{overflow:auto;border-radius:8px;background:#fff;border:1px solid var(--line);cursor:zoom-in;max-height:none}
.scan img{display:block;width:auto;max-width:100%;height:auto;margin:0 auto}
.scan:not(.zoomed) img{max-width:min(100%,840px)}
.scan-head:not(.zoomed) img{max-width:min(100%,540px)}
.scan.zoomed{cursor:zoom-out}
.scan.zoomed img{width:auto;max-width:none;min-width:100%;margin:0}

/* ---------- printable sheets ---------- */
.sheet{display:flex;flex-direction:column;background:var(--surface);border:1px solid var(--line);border-radius:14px;overflow:hidden;box-shadow:var(--shadow);transition:transform .2s ease,box-shadow .2s ease}
.sheet:hover{transform:translateY(-3px);box-shadow:var(--shadow-lift)}
.sheet-thumb{display:block;background:var(--sunken);padding:14px 14px 0;position:relative}
.sheet-thumb img{display:block;width:100%;height:auto;border:1px solid var(--line);border-radius:6px 6px 0 0;box-shadow:0 -1px 12px rgba(0,0,0,.10)}
.sheet-thumb .badge{position:absolute;top:20px;right:20px;background:var(--ink);color:var(--surface);font-family:'Chakra Petch',sans-serif;font-size:11px;font-weight:700;letter-spacing:.06em;padding:3px 9px;border-radius:20px}
.sheet-body{padding:16px 18px 18px;display:flex;flex-direction:column;gap:10px;flex:1}
.sheet-body h3{margin:0;font-size:17px}
.sheet-body p{margin:0;font-size:14px;color:var(--ink-2)}
.sheet-meta{list-style:none;margin:0;padding:0;display:flex;flex-wrap:wrap;gap:6px}
.sheet-meta li{font-size:11.5px;font-family:'Chakra Petch',sans-serif;font-weight:600;letter-spacing:.03em;color:var(--ink-2);background:var(--sunken);border:1px solid var(--line);border-radius:20px;padding:2px 9px}
.sheet-actions{display:flex;gap:8px;flex-wrap:wrap;margin-top:auto;padding-top:4px}
.sheet-actions .btn{text-decoration:none}
.pickbar{display:flex;gap:6px;flex-wrap:wrap;margin-bottom:12px}
.viewer{width:100%;height:min(78vh,900px);border:1px solid var(--line);border-radius:11px;background:var(--sunken)}
.rec{border:1px dashed var(--addr);background:var(--addr-soft);border-radius:11px;padding:12px 15px;font-size:14px}
.rec b{color:var(--addr)}
@media print{.topbar,.hero,.sheet-actions,.banner{display:none}}

footer{margin-top:72px;padding-top:24px;border-top:1px solid var(--line);color:var(--ink-3);font-size:13.5px}
.filterbar{display:flex;gap:6px;flex-wrap:wrap;margin-bottom:14px}