:root{
  --bg:#eef2f4; --panel:#ffffff; --ink:#15242c; --muted:#5a6a73; --faint:#8a99a1;
  --line:#e0e7eb; --line2:#eef2f4;
  --acc:#0e7c86; --acc-deep:#0a5a62; --acc-soft:#e6f2f3; --acc-mid:#bfe0e2;
  --sky:#2f6f9f; --sky-soft:#e9f1f8;
  --warn:#b06d17; --warn-soft:#fbf2e3; --warn-line:#ecca8f;
  --ok:#2e7d5b; --ok-soft:#e7f4ee;
  --sat:#334652;
  --serif:"Hiragino Mincho ProN","Yu Mincho","YuMincho",serif;
  --sans:-apple-system,"Hiragino Kaku Gothic ProN","Yu Gothic","YuGothic",Meiryo,sans-serif;
  --sh:0 2px 14px rgba(20,45,50,.06);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--sans);line-height:1.95;font-size:16px;-webkit-text-size-adjust:100%;text-underline-offset:2px}
img{max-width:100%;display:block}
a{color:var(--acc-deep)}
.wrap{max-width:880px;margin:0 auto;padding:0 20px}
b,strong{font-weight:800}
mark{background:linear-gradient(transparent 62%,#ffe9b8 62%);padding:0 1px}

/* header + series nav */
header.top{position:sticky;top:0;z-index:30;background:rgba(255,255,255,.92);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.top .wrap{display:flex;align-items:center;gap:14px;min-height:56px;flex-wrap:wrap;padding-top:6px;padding-bottom:6px}
.top .logo{font-weight:800;font-size:15px;color:var(--ink);text-decoration:none;display:flex;align-items:center;gap:7px;white-space:nowrap}
.top .logo .b{color:var(--acc)}
.series{display:flex;gap:4px;flex-wrap:wrap}
.series a{font-size:12.5px;color:var(--muted);text-decoration:none;padding:5px 11px;border-radius:8px;white-space:nowrap}
.series a:hover{background:var(--acc-soft);color:var(--acc-deep)}
.series a.on{background:var(--acc);color:#fff;font-weight:700}
.top .home{margin-left:auto;font-size:12.5px;color:var(--muted);text-decoration:none;border:1px solid var(--line);border-radius:8px;padding:6px 12px;white-space:nowrap}
.top .home:hover{border-color:var(--acc);color:var(--acc-deep)}
@media(max-width:640px){.top .home{display:none}}

/* hero */
.hero{position:relative;overflow:hidden;background:linear-gradient(150deg,#083f45,#0e7c86 55%,#2f6f9f);color:#fff;padding:50px 0 46px}
.hero.alt{background:linear-gradient(150deg,#0a4a63,#2f6f9f 55%,#0e7c86)}
.hero::after{content:"";position:absolute;inset:0;background-image:radial-gradient(circle at 85% 20%,rgba(255,255,255,.14),transparent 42%),radial-gradient(circle at 15% 90%,rgba(255,255,255,.08),transparent 40%);pointer-events:none}
.hero .wrap{position:relative;z-index:1}
.hero .eyebrow{font-size:12px;letter-spacing:.2em;font-weight:700;opacity:.92;text-transform:uppercase}
.hero h1{font-family:var(--serif);font-size:clamp(25px,4.8vw,38px);line-height:1.34;margin:12px 0 14px;font-weight:800;letter-spacing:.01em}
.hero p{margin:0;font-size:15.5px;line-height:1.95;opacity:.97;max-width:54em}
.hero .tags{display:flex;flex-wrap:wrap;gap:8px;margin-top:20px}
.hero .tags span{background:rgba(255,255,255,.15);border:1px solid rgba(255,255,255,.32);border-radius:999px;padding:5px 13px;font-size:12px;font-weight:600}

/* summary */
.summary{background:var(--panel);border:1px solid var(--line);border-left:5px solid var(--acc);border-radius:12px;box-shadow:var(--sh);padding:18px 22px;margin:26px 0 6px}
.summary h2{font-size:13px;letter-spacing:.08em;color:var(--acc-deep);margin:0 0 8px;font-weight:800}
.summary ul{margin:0;padding-left:1.2em;columns:2;column-gap:26px;font-size:14px}
.summary li{margin-bottom:5px}
@media(max-width:600px){.summary ul{columns:1}}

/* toc */
.toc{background:linear-gradient(180deg,#fff,#fbfdfd);border:1px solid var(--line);border-radius:14px;box-shadow:var(--sh);padding:18px 22px;margin:16px 0 8px}
.toc h2{font-size:13px;letter-spacing:.1em;color:var(--muted);margin:0 0 10px;font-weight:800}
.toc ol{margin:0;padding-left:0;list-style:none;counter-reset:t;columns:2;column-gap:28px}
.toc li{margin-bottom:7px;font-size:14px;break-inside:avoid;counter-increment:t;position:relative;padding-left:30px}
.toc li::before{content:counter(t,decimal-leading-zero);position:absolute;left:0;top:0;font-size:11px;font-weight:800;color:var(--acc);background:var(--acc-soft);border-radius:5px;padding:1px 5px}
.toc a{color:var(--ink);text-decoration:none} .toc a:hover{color:var(--acc-deep)}
@media(max-width:600px){.toc ol{columns:1}}

/* sections */
section{padding:26px 0 6px;scroll-margin-top:104px}
.sec-head{display:flex;align-items:center;gap:12px;margin:0 0 6px}
.sec-num{flex:none;font-family:var(--serif);font-size:26px;font-weight:800;color:var(--acc-mid);line-height:1}
h2.sec{font-family:var(--serif);font-size:clamp(20px,3.3vw,27px);font-weight:800;margin:0;line-height:1.4}
.sec-rule{height:2px;background:linear-gradient(90deg,var(--acc),var(--acc-mid) 40%,transparent);border-radius:2px;margin:6px 0 18px}
h3{font-size:17.5px;font-weight:800;margin:28px 0 10px;color:var(--acc-deep);display:flex;align-items:center;gap:8px}
h3::before{content:"";width:8px;height:8px;border-radius:2px;background:var(--acc);transform:rotate(45deg);flex:none}
h4{font-size:15px;font-weight:800;margin:18px 0 6px}
p{margin:0 0 15px}
ul,ol{margin:0 0 16px;padding-left:1.4em} li{margin-bottom:7px}
.lead{font-size:16.5px}

/* cards & callouts */
.card{background:var(--panel);border:1px solid var(--line);border-radius:14px;box-shadow:var(--sh);padding:20px 22px;margin:16px 0}
.callout{background:var(--acc-soft);border:1px solid var(--acc-mid);border-left:5px solid var(--acc);border-radius:0 12px 12px 0;padding:14px 18px;margin:16px 0;font-size:14.5px}
.callout .lbl{font-weight:800;color:var(--acc-deep);display:block;margin-bottom:2px;font-size:13px;letter-spacing:.04em}
.warn{background:var(--warn-soft);border:1px solid var(--warn-line);border-left:5px solid var(--warn);border-radius:0 12px 12px 0;padding:14px 18px;margin:16px 0;font-size:14.5px}
.warn .lbl{font-weight:800;color:var(--warn);display:block;margin-bottom:2px;font-size:13px}
.tip{background:var(--ok-soft);border:1px solid #bfe3d1;border-left:5px solid var(--ok);border-radius:0 12px 12px 0;padding:14px 18px;margin:16px 0;font-size:14.5px}
.tip .lbl{font-weight:800;color:var(--ok);display:block;margin-bottom:2px;font-size:13px}

/* figures */
figure{margin:20px 0;background:var(--panel);border:1px solid var(--line);border-radius:14px;box-shadow:var(--sh);padding:20px;overflow:hidden}
figure svg{display:block;width:100%;height:auto}
figcaption{font-size:12.5px;color:var(--muted);text-align:center;margin-top:12px;line-height:1.7}

/* photo placeholder */
.photo{margin:18px 0;border:2px dashed var(--sky);border-radius:14px;background:var(--sky-soft);min-height:140px;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;color:var(--sky);padding:22px}
.photo .ic{font-size:28px} .photo b{font-size:14px;margin-top:5px;color:var(--sky)} .photo small{font-size:11.5px;color:var(--muted);margin-top:3px;max-width:36em;line-height:1.6}

/* compare */
.compare{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin:16px 0}
@media(max-width:640px){.compare{grid-template-columns:1fr}}
.compare .col{background:var(--panel);border:1px solid var(--line);border-radius:14px;box-shadow:var(--sh);padding:18px 20px}
.compare .col.a{border-top:4px solid var(--sky)} .compare .col.b{border-top:4px solid var(--acc)}
.compare h4{margin:0 0 4px;font-size:16px}
.compare .col.a h4{color:var(--sky)} .compare .col.b h4{color:var(--acc-deep)}
.compare .sub{font-size:12px;color:var(--muted);margin-bottom:10px}
.compare ul{margin:0;padding-left:1.2em;font-size:14px} .compare li{margin-bottom:6px}

/* table */
.tbl-scroll{overflow-x:auto;margin:14px 0;border-radius:12px;border:1px solid var(--line);box-shadow:var(--sh)}
.tbl{width:100%;border-collapse:collapse;font-size:13.5px;min-width:520px;background:var(--panel)}
.tbl th,.tbl td{border-bottom:1px solid var(--line);border-right:1px solid var(--line2);padding:10px 13px;text-align:left;vertical-align:top}
.tbl th{background:var(--acc-soft);color:var(--acc-deep);font-weight:800;white-space:nowrap}
.tbl td:first-child{font-weight:700}
.tbl tr:last-child td{border-bottom:none}
.tbl tr:nth-child(even) td{background:#fafcfc}
.note-s{font-size:12px;color:var(--faint);margin:-6px 0 14px}

/* code chips */
.kv{display:flex;flex-wrap:wrap;gap:8px;margin:10px 0 4px}
.kv .chip{background:#0e2b2f;color:#c8ecee;border-radius:8px;padding:6px 12px;font-size:13px;font-family:"SFMono-Regular",Consolas,monospace}
.kv .chip b{color:#fff;font-weight:700}
code{background:var(--line2);border:1px solid var(--line);border-radius:5px;padding:1px 6px;font-size:12.5px;color:var(--ink);font-family:"SFMono-Regular",Consolas,monospace}

/* steps */
.steps{counter-reset:st;list-style:none;padding:0;margin:18px 0}
.steps>li{position:relative;padding:2px 0 18px 60px;margin-bottom:4px;border-left:2px solid var(--acc-mid);margin-left:17px}
.steps>li:last-child{border-left-color:transparent;padding-bottom:2px}
.steps>li::before{counter-increment:st;content:counter(st);position:absolute;left:-18px;top:-2px;width:36px;height:36px;border-radius:50%;background:var(--acc);color:#fff;display:grid;place-items:center;font-weight:800;font-size:16px;box-shadow:0 2px 6px rgba(14,124,134,.35)}
.steps b{display:block;font-size:15.5px;margin-bottom:3px}
.steps .d{font-size:14px;color:var(--muted)}
.steps .d code{background:#fff}

/* faq */
.faq{border:1px solid var(--line);border-radius:12px;background:var(--panel);margin-bottom:10px;overflow:hidden;box-shadow:var(--sh)}
.faq summary{cursor:pointer;padding:14px 44px 14px 18px;font-weight:800;font-size:15px;list-style:none;position:relative}
.faq summary::-webkit-details-marker{display:none}
.faq summary::before{content:"Q";color:var(--acc);font-weight:800;margin-right:8px}
.faq summary::after{content:"＋";position:absolute;right:16px;top:13px;color:var(--muted);font-weight:700}
.faq[open] summary::after{content:"－"}
.faq[open] summary{border-bottom:1px solid var(--line2)}
.faq .a{padding:14px 18px;color:var(--muted);font-size:14px;line-height:1.9}
.faq .a::before{content:"A";color:var(--warn);font-weight:800;margin-right:8px}

/* glossary */
.glo{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin:14px 0}
@media(max-width:640px){.glo{grid-template-columns:1fr}}
.glo div{background:var(--panel);border:1px solid var(--line);border-radius:10px;padding:12px 15px}
.glo dt{font-weight:800;font-size:14px;color:var(--acc-deep)}
.glo dd{margin:3px 0 0;font-size:13px;color:var(--muted);line-height:1.75}

/* related pages */
.related{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:20px 0 6px}
@media(max-width:600px){.related{grid-template-columns:1fr}}
.related a{display:block;background:var(--panel);border:1px solid var(--line);border-radius:12px;box-shadow:var(--sh);padding:16px 18px;text-decoration:none;color:var(--ink)}
.related a:hover{border-color:var(--acc)}
.related .k{font-size:11px;letter-spacing:.1em;color:var(--acc);font-weight:800}
.related b{display:block;margin:3px 0 2px;font-size:15px}
.related small{color:var(--muted);font-size:12.5px}

/* footer */
footer{background:#0a1c20;color:#c3d4d6;margin-top:44px;padding:32px 0 44px;font-size:13px;line-height:1.9}
footer h3{color:#fff;font-size:14px;margin:0 0 10px;display:block}
footer h3::before{display:none}
footer a{color:#8fd3d8}
footer .src li{margin-bottom:6px}
footer .disc{margin-top:20px;padding-top:16px;border-top:1px solid rgba(255,255,255,.14);color:#8ea1a4;font-size:12px}
.updated{font-size:12px;color:#8ea1a4;margin-top:6px}

/* ===== 追加機能：ダークモード・印刷・ツール類 ===== */
/* header tools */
.hdr-tools{margin-left:auto;display:flex;align-items:center;gap:8px}
.hdr-tools .home{margin-left:0}
.tool-btn{border:1px solid var(--line);background:var(--panel);color:var(--muted);width:34px;height:34px;border-radius:9px;cursor:pointer;font-size:15px;line-height:1;display:grid;place-items:center;padding:0}
.tool-btn:hover{border-color:var(--acc);color:var(--acc-deep)}
@media(max-width:640px){.tool-btn{width:32px;height:32px}}

/* copy chip button */
.copy-btn{border:1px solid var(--acc);background:var(--acc-soft);color:var(--acc-deep);border-radius:8px;padding:6px 12px;font-size:12.5px;font-weight:700;cursor:pointer;margin:2px 0 8px}
.copy-btn:hover{background:var(--acc);color:#fff}

/* to-top */
.to-top{position:fixed;right:18px;bottom:18px;z-index:40;width:44px;height:44px;border-radius:50%;border:none;background:var(--acc);color:#fff;font-size:20px;cursor:pointer;box-shadow:0 4px 14px rgba(0,0,0,.25);opacity:0;pointer-events:none;transition:opacity .2s,transform .2s;transform:translateY(8px)}
.to-top.show{opacity:1;pointer-events:auto;transform:translateY(0)}
.to-top:hover{background:var(--acc-deep)}

/* toc active (scroll-spy) */
.toc a.active{color:var(--acc-deep);font-weight:800}
.toc li:has(a.active)::before{background:var(--acc);color:#fff}

/* ===== ダークモード ===== */
:root[data-theme="dark"]{
  --bg:#0f1c21; --panel:#17262c; --ink:#e7eef0; --muted:#a2b2b8; --faint:#7b8c92;
  --line:#283a41; --line2:#1d2d33;
  --acc:#3fb6c0; --acc-deep:#82d4da; --acc-soft:#12333a; --acc-mid:#2c565e;
  --sky:#6fb2e2; --sky-soft:#13293a;
  --warn:#e0a862; --warn-soft:#2c2416; --warn-line:#584327;
  --ok:#63c99c; --ok-soft:#122a20;
  --sh:0 2px 16px rgba(0,0,0,.34);
}
:root[data-theme="dark"] header.top{background:rgba(23,38,44,.9)}
:root[data-theme="dark"] .toc{background:linear-gradient(180deg,#17262c,#14232a)}
:root[data-theme="dark"] .tbl tr:nth-child(even) td{background:#1b2b31}
:root[data-theme="dark"] figure{background:#eef3f4} /* 図は白地のまま＝SVGの視認性を確保 */
:root[data-theme="dark"] figure figcaption{color:#5a6a73}
:root[data-theme="dark"] .photo{background:#13293a}
:root[data-theme="dark"] mark{background:linear-gradient(transparent 62%,rgba(224,168,98,.4) 62%);color:inherit}

/* ===== 印刷 ===== */
@media print{
  header.top,.to-top,.hdr-tools,.hero .tags,.copy-btn,.related{display:none!important}
  body{background:#fff;color:#000;font-size:11.5pt;line-height:1.7}
  .hero{background:#fff!important;color:#000;padding:6px 0 12px;border-bottom:2px solid #000}
  .hero::after{display:none}
  .hero .eyebrow,.hero h1,.hero p{color:#000;opacity:1}
  .wrap{max-width:none}
  figure,.card,.callout,.warn,.tip,.faq,.toc,.summary,.compare .col,.tbl-scroll{box-shadow:none;break-inside:avoid}
  details.faq>*{display:block!important} /* FAQを開いて印刷 */
  a{color:#000;text-decoration:underline}
  footer{background:#fff;color:#000;border-top:2px solid #000}
  footer h3,footer a{color:#000}
  section{padding:10px 0}
}

/* 工程ごとの写真差し替え枠（コンパクト） */
.shot{display:flex;align-items:center;justify-content:center;gap:7px;margin:10px 0 2px;padding:11px;border:1.5px dashed var(--sky);border-radius:9px;background:var(--sky-soft);color:var(--sky);font-size:11.5px;font-weight:700;text-align:center;line-height:1.5}
.shot::before{content:"📷";font-size:15px}
:root[data-theme="dark"] .shot{background:#13293a}
@media print{.shot{display:none!important}}