:root{--paper:#F5F7FB;--card:#fff;--ink:#111A33;--muted:#5A6478;--blue:#1E3FAE;--blue-d:#162F85;--hl:#FFE45C;--line:#DDE2EE;--ok:#12805C;--bad:#B42318}
html{-webkit-text-size-adjust:100%;text-size-adjust:100%}
*{box-sizing:border-box}
body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.6 system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif}
h1,h2,h3{line-height:1.2;letter-spacing:-.02em}
a{color:var(--blue)}
:focus-visible{outline:3px solid var(--blue);outline-offset:2px}
.wrap{max-width:1120px;margin:0 auto;padding-left:16px;padding-right:16px}
.hidden{display:none}

/* ---------- header ---------- */
header.top{background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:50}
.bar{display:flex;align-items:center;justify-content:space-between;min-height:60px;position:relative}
.brand{display:flex;align-items:center;gap:9px;color:var(--ink);text-decoration:none;font-weight:800;font-size:1.3rem;letter-spacing:-.03em}
.logo{width:26px;height:26px;border-radius:7px;background:var(--ink);position:relative;display:inline-block}
.logo::after{content:"";position:absolute;right:-4px;bottom:-4px;width:12px;height:12px;border-radius:3px;background:var(--hl);border:2px solid #fff}
.burger{width:44px;height:44px;border:0;background:none;padding:0;margin:0 -8px 0 0;display:flex;flex-direction:column;justify-content:center;align-items:center;gap:5px;cursor:pointer;border-radius:8px}
.burger span{display:block;width:22px;height:2px;background:var(--ink)}
.menu{display:none;position:absolute;top:100%;left:0;right:0;background:#fff;border-bottom:1px solid var(--line);padding:4px 16px 12px;max-height:calc(100vh - 62px);overflow:auto}
.menu.open{display:block}
.ddb{display:flex;width:100%;justify-content:space-between;align-items:center;background:none;border:0;border-top:1px solid var(--line);padding:14px 2px;font:inherit;font-weight:600;color:var(--ink);cursor:pointer;text-align:left}
.ddb::after{content:"";width:8px;height:8px;border-right:2px solid currentColor;border-bottom:2px solid currentColor;transform:rotate(45deg);margin:-4px 4px 0 8px;transition:transform .15s}
.dd.open .ddb::after{transform:rotate(-135deg);margin-top:4px}
.dd:first-child .ddb{border-top:0}
.ddp{display:none;padding:0 0 8px 10px}
.dd.open .ddp{display:block}
.ddp a{display:block;padding:9px 4px;color:var(--ink);text-decoration:none}
.ddp a:hover{color:var(--blue)}
.menu .plain{display:block;border-top:1px solid var(--line);padding:14px 2px;font-weight:600;color:var(--ink);text-decoration:none}
.dd.on .ddb{color:var(--blue)}
@media(min-width:900px){
  .burger{display:none}
  .menu{display:flex;position:static;padding:0;border:0;max-height:none;overflow:visible;align-items:stretch;gap:2px;background:none}
  .dd{position:relative;display:flex}
  .ddb{border:0;padding:0 12px;min-height:60px;width:auto;font-size:.95rem}
  .dd:first-child .ddb{border-top:0}
  .ddb::after{margin:-4px 0 0 8px}
  .dd.open .ddb::after{margin-top:4px}
  .dd.on .ddb{box-shadow:inset 0 -3px 0 var(--hl)}
  .ddp{position:absolute;top:100%;left:0;min-width:230px;background:#fff;border:1px solid var(--line);border-radius:10px;padding:6px;box-shadow:0 10px 28px rgba(17,26,51,.12)}
  .ddp a{padding:9px 12px;border-radius:6px}
  .ddp a:hover{background:var(--paper)}
  .menu .plain{border:0;padding:0 12px;display:flex;align-items:center;min-height:60px;font-size:.95rem}
}
@media(min-width:900px) and (hover:hover){.dd:hover .ddp{display:block}}

/* ---------- home ---------- */
.herob{padding:32px 0 16px}
.herob h1{font-size:clamp(2rem,6vw,3.5rem);font-weight:800;letter-spacing:-.035em;line-height:1.05;margin:0 0 14px;max-width:19ch}
.herob .lead{font-size:1.1rem;color:var(--muted);max-width:56ch;margin:0 0 20px}
.cta{display:flex;flex-wrap:wrap;gap:10px}
a.btn{display:inline-block;padding:12px 18px;background:var(--blue);color:#fff;border-radius:10px;text-decoration:none;font-weight:700}
a.btn:hover{background:var(--blue-d)}
a.btn.ghost{background:transparent;color:var(--ink);border:1px solid var(--ink)}
a.btn.ghost:hover{background:var(--hl)}
.sizes{margin-top:30px}
.ruler{height:16px;background:linear-gradient(90deg,var(--ink) 0 1px,transparent 1px) left bottom/50px 16px repeat-x,linear-gradient(90deg,var(--ink) 0 1px,transparent 1px) left bottom/10px 8px repeat-x}
.sizes h2{font-size:1rem;margin:10px 0 12px;font-weight:600;color:var(--muted);letter-spacing:0}
.chips{display:grid;grid-template-columns:repeat(2,1fr);gap:10px}
@media(min-width:560px){.chips{grid-template-columns:repeat(4,1fr)}}
@media(min-width:900px){.chips{grid-template-columns:repeat(8,1fr)}}
.chip{display:flex;flex-direction:column;justify-content:center;padding:14px;background:#fff;border:1px solid var(--line);border-radius:12px;text-decoration:none;color:var(--ink);min-height:88px;transition:background .15s,border-color .15s}
.chip b{font-size:1.9rem;line-height:1;font-weight:800;letter-spacing:-.03em;font-variant-numeric:tabular-nums}
.chip span{font-size:.85rem;color:var(--muted);margin-top:6px}
.chip:hover,.chip:focus-visible{background:var(--hl);border-color:var(--ink)}
.chip:hover span{color:var(--ink)}
.sect{padding-top:28px;padding-bottom:8px}
.sect>h2{font-size:1.5rem;margin:0 0 14px}
.index{border-top:2px solid var(--ink)}
.irow{display:grid;gap:10px;padding:16px 0;border-bottom:1px solid var(--line)}
@media(min-width:820px){.irow{grid-template-columns:280px 1fr;gap:24px}}
.irow h3{margin:0;font-size:1.1rem}
.irow p{margin:2px 0 0;color:var(--muted);font-size:.92rem}
.pills{display:flex;flex-wrap:wrap;gap:8px;align-content:flex-start}
.pill{display:inline-block;padding:8px 14px;background:#fff;border:1px solid var(--line);border-radius:999px;color:var(--ink);text-decoration:none;font-size:.95rem}
.pill:hover,.pill:focus-visible{background:var(--hl);border-color:var(--ink)}
.steps{list-style:none;margin:0;padding:0;display:grid;gap:12px;counter-reset:s}
@media(min-width:760px){.steps{grid-template-columns:repeat(3,1fr);gap:20px}}
.steps li{counter-increment:s;background:#fff;border:1px solid var(--line);border-radius:12px;padding:16px 16px 16px 62px;position:relative}
.steps li::before{content:counter(s);position:absolute;left:16px;top:16px;width:32px;height:32px;border-radius:50%;background:var(--hl);color:var(--ink);font-weight:800;display:grid;place-items:center}
.steps b{display:block}
.steps span{color:var(--muted);font-size:.95rem}
.band{background:var(--ink);color:#fff;margin-top:32px;padding:36px 0}
.band h2{margin:0 0 8px;font-size:1.5rem}
.band p{margin:0;max-width:60ch;color:#C9D1E6}
.faq details{background:#fff;border:1px solid var(--line);border-radius:10px;padding:2px 14px;margin-bottom:8px}
.faq summary{cursor:pointer;font-weight:600;padding:12px 0}
.faq details p{margin:0 0 12px;color:#344054}

/* ---------- plain pages (privacy, about, contact) ---------- */
.hero{max-width:1120px;margin:0 auto;padding:28px 16px 0}
.hero h1{margin:0;font-size:clamp(1.7rem,4vw,2.4rem);font-weight:800;letter-spacing:-.03em}
main{max-width:1120px;margin:0 auto;padding:16px}
main>article.card:only-child{max-width:760px}

/* ---------- tool pages ---------- */
.thero{padding:20px 0 4px}
.crumbs{font-size:.88rem;color:var(--muted)}
.crumbs a{color:var(--muted)}
.thero h1{font-size:clamp(1.6rem,4.5vw,2.5rem);margin:6px 0;font-weight:800;letter-spacing:-.03em}
.thero p{margin:0;color:var(--muted);max-width:62ch}
.layout{display:grid;gap:18px;padding-top:16px;padding-bottom:28px}
.layout>*{min-width:0}
@media(min-width:960px){
  .layout{grid-template-columns:minmax(0,1fr) 300px;gap:28px}
  .side{position:sticky;top:76px;align-self:start}
}
.card{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:16px;margin-bottom:16px}
.drop{border:2px dashed var(--blue);border-radius:12px;padding:34px 12px;text-align:center;cursor:pointer;background:#F1F4FF;display:block;margin:0;font-weight:400}
.drop:hover{background:#E8EDFF}
.drop strong{display:block;font-size:1.1rem}
.drop span{color:var(--muted);font-size:.9rem}
input[type=file]{display:none}
label{display:block;font-weight:600;font-size:.9rem;margin:12px 0 4px}
input[type=number],select{width:100%;padding:10px;border:1px solid var(--line);border-radius:8px;font-size:1rem;background:#fff;color:var(--ink)}
input[type=range]{width:100%}
.row{display:flex;gap:10px}
.row>div{flex:1}
.check{display:flex;align-items:center;gap:8px;margin-top:12px;font-size:.95rem}
.check input{width:18px;height:18px}
.check label{margin:0;font-weight:400}
.card button{width:100%;margin-top:16px;padding:13px;border:0;border-radius:10px;background:var(--blue);color:#fff;font-size:1.05rem;font-weight:700;cursor:pointer}
.card button:hover{background:var(--blue-d)}
.card button:disabled{background:#B8C0E0;cursor:not-allowed}
.card button.alt{background:#fff;color:var(--blue);border:1px solid var(--blue);margin-top:0}
.card button.alt:hover{background:#F1F4FF}
.btns{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-top:12px}
.stats{display:flex;gap:10px;flex-wrap:wrap}
.stat{flex:1;min-width:110px;background:var(--paper);border-radius:10px;padding:10px;text-align:center}
.stat b{display:block;font-size:1.05rem}
.stat small{color:var(--muted)}
#sn{background:var(--hl);color:var(--ink);border-radius:4px;display:inline-block;padding:0 8px}
img.preview{max-width:100%;max-height:340px;display:block;margin:14px auto 0;border-radius:8px;border:1px solid var(--line)}
canvas.work{max-width:100%;height:auto;display:block;margin:12px auto 0;border-radius:8px;border:1px solid var(--line);touch-action:none;background:#eee}
#msg{margin-top:10px;font-size:.9rem;color:var(--muted);text-align:center}
#tmsg{margin-top:10px;font-size:.9rem;color:var(--bad);text-align:center}
.note{margin-top:8px;font-size:.88rem;color:var(--muted);text-align:center}
article h2{font-size:1.15rem;margin:22px 0 8px}
article h2:first-child{margin-top:0}
article p,article li{color:#344054;max-width:72ch}
article details{border-top:1px solid var(--line);padding:10px 0}
article details:first-of-type{border-top:0}
article summary{cursor:pointer;font-weight:600}
article details p{margin:8px 0 0}
.sidecard h2{font-size:1rem;margin:0 0 6px}
.sidecard a{display:block;padding:8px 0;border-top:1px solid var(--line);color:var(--ink);text-decoration:none;font-size:.95rem}
.sidecard h2+a{border-top:0}
.sidecard a:hover{color:var(--blue);text-decoration:underline}

/* ---------- footer ---------- */
.foot{background:#fff;border-top:1px solid var(--line);margin-top:24px;padding:28px 0 22px}
.fcols{display:grid;grid-template-columns:repeat(2,1fr);gap:22px}
@media(min-width:760px){.fcols{grid-template-columns:repeat(6,1fr)}}
.fcol h3{font-size:.95rem;margin:0 0 8px}
.fcol a{display:block;color:var(--muted);text-decoration:none;font-size:.9rem;padding:4px 0}
.fcol a:hover{color:var(--blue);text-decoration:underline}
.fbase{display:flex;flex-wrap:wrap;gap:10px 24px;justify-content:space-between;margin-top:24px;padding-top:16px;border-top:1px solid var(--line);font-size:.88rem;color:var(--muted)}
.fbase a{color:var(--muted);margin-right:16px}

@media(prefers-reduced-motion:reduce){*{transition:none!important}}