:root {
  --paper: #f3efe7;
  --paper-2: #e9e3d7;
  --ink: #23211d;
  --muted: #6e685d;
  --line: #d3cbbb;
  --green: #344b3c;
  --green-soft: #5f7a66;
  --clay: #a5583a;
  --mincho: "Shippori Mincho", "Hiragino Mincho ProN", "Yu Mincho", serif;
  --gothic: "Zen Kaku Gothic New", "Hiragino Sans", "Yu Gothic", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, monospace;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: 72px; }
body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--gothic);
  font-size: 16px;
  line-height: 1.9;
  letter-spacing: .02em;
}
a { color: inherit; }
img, svg { display: block; max-width: 100%; }

html.lang-ja .en, html.lang-en .ja { display: none !important; }
html.lang-en body { line-height: 1.7; letter-spacing: 0; }

.wrap { max-width: 1120px; margin: 0 auto; padding: 0 clamp(20px, 4vw, 40px); }
.small { font-size: .85rem; }
.muted { color: var(--muted); }

/* ---------- header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 10;
  background: rgba(243, 239, 231, .94);
  border-bottom: 1px solid var(--line);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; gap: 24px; }
.wordmark {
  font-family: var(--mincho); font-weight: 700;
  letter-spacing: .32em; font-size: 1.05rem; text-decoration: none;
}
.nav { display: flex; gap: 28px; font-size: .9rem; }
.nav a, .footer-links a { text-decoration: none; color: var(--muted); }
.nav a:hover, .footer-links a:hover { color: var(--ink); }
.header-actions { display: flex; align-items: center; gap: 18px; font-size: .9rem; }
.lang {
  font: 500 .78rem var(--mono); letter-spacing: .08em;
  background: none; border: 1px solid var(--line); color: var(--ink);
  padding: 4px 10px; cursor: pointer;
}
.lang:hover { border-color: var(--ink); }
.link-order { text-decoration: none; border-bottom: 1px solid var(--ink); padding-bottom: 1px; }

/* ---------- buttons ---------- */
.btn {
  display: inline-block; text-decoration: none; cursor: pointer;
  font: 500 .95rem var(--gothic); letter-spacing: .05em;
  background: var(--green); color: var(--paper);
  border: 1px solid var(--green);
  padding: 14px 26px;
  transition: background .2s, color .2s;
}
.btn:hover { background: var(--ink); border-color: var(--ink); }
.btn-line { background: transparent; color: var(--ink); border-color: var(--ink); }
.btn-line:hover { background: var(--ink); color: var(--paper); }

/* ---------- hero ---------- */
.hero {
  display: grid; grid-template-columns: 1fr 1.15fr; gap: clamp(32px, 5vw, 72px);
  align-items: center;
  padding-top: clamp(48px, 8vw, 96px); padding-bottom: clamp(56px, 8vw, 104px);
}
.status { display: flex; align-items: center; gap: 10px; font-size: .85rem; color: var(--green); margin-bottom: 28px; }
.dot { width: 7px; height: 7px; border-radius: 50%; background: var(--clay); }
h1 {
  font-family: var(--mincho); font-weight: 700;
  font-size: clamp(2.4rem, 5.2vw, 4rem); line-height: 1.35; letter-spacing: .04em;
}
html.lang-en h1 { letter-spacing: -.01em; line-height: 1.15; }
.lead { margin: 28px 0 36px; color: #4a463e; max-width: 30em; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; }

.hero-figure { margin: 0; }
.panel { background: var(--paper-2); padding: clamp(14px, 2.5vw, 28px); border: 1px solid var(--line); }
.panel svg { width: 100%; height: auto; }
.case { fill: #dcd5c7; stroke: var(--ink); stroke-width: 2; }
.glass-bg { fill: #ece7dd; }
.parts * { fill: none; stroke: #9d968a; stroke-width: 1.5; }
.parts .board { fill: #e3ddd1; }
.parts .solid { fill: #d6cfc1; }
.parts .hub { fill: #d6cfc1; }
.parts .tube { stroke: #b4ada1; stroke-width: 7; stroke-linecap: round; }
.reflect { fill: #fff; opacity: .28; }

.layer { opacity: 0; transition: opacity .5s ease; }
.panel[data-mode="stats"] .layer-stats,
.panel[data-mode="art"] .layer-art { opacity: 1; }
.tint { fill: #f6f3ec; opacity: .42; }
.d-big { font: 500 92px var(--mono); fill: var(--green); }
.d-small, .d-label { font: 500 15px var(--mono); fill: var(--green); letter-spacing: .12em; }
.d-val { font: 500 20px var(--mono); fill: var(--green); }
.d-track { fill: var(--green); opacity: .18; }
.d-fill { fill: var(--clay); transition: width .8s; }
.art-ring { fill: none; stroke: var(--clay); stroke-width: 2; opacity: .8; }
.art-kanji { font: 700 190px var(--mincho); fill: var(--green); opacity: .82; }
.art-caption { font: 500 16px var(--mono); letter-spacing: .6em; fill: var(--green); }

.modes { display: flex; border: 1px solid var(--line); border-top: 0; }
.modes button {
  flex: 1; padding: 10px 6px; cursor: pointer;
  background: var(--paper); border: 0; border-right: 1px solid var(--line);
  font: .85rem var(--gothic); color: var(--muted);
}
.modes button:last-child { border-right: 0; }
.modes button.on { background: var(--ink); color: var(--paper); }
.hero-figure figcaption { font-size: .78rem; color: var(--muted); margin-top: 10px; }

/* ---------- sections ---------- */
.section { padding-top: clamp(64px, 9vw, 112px); padding-bottom: clamp(64px, 9vw, 112px); }
.band { background: var(--paper-2); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.section-title { display: flex; align-items: baseline; gap: 18px; margin-bottom: 36px; }
.kicker { font: 500 .8rem var(--mono); color: var(--clay); }
h2 { font-family: var(--mincho); font-weight: 700; font-size: clamp(1.6rem, 3vw, 2.2rem); line-height: 1.4; letter-spacing: .04em; }
h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: 8px; }
.body { color: #4a463e; margin-bottom: 32px; max-width: 34em; }
.narrow { max-width: 38em; }

.three { display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid var(--ink); }
.three article { padding: 28px 28px 8px 0; }
.three article + article { padding-left: 28px; border-left: 1px solid var(--line); }
.three p { color: #4a463e; font-size: .95rem; }

.build-grid { display: grid; grid-template-columns: 1fr 1.1fr; gap: clamp(32px, 6vw, 80px); align-items: start; }
.spec { border-top: 1px solid var(--ink); }
.spec div { display: grid; grid-template-columns: 9em 1fr; gap: 16px; padding: 16px 0; border-bottom: 1px solid var(--line); }
.spec dt { color: var(--muted); font-size: .9rem; }
.spec dd { font-size: .95rem; }

.flow { list-style: none; display: grid; grid-template-columns: repeat(4, 1fr); gap: 0; border-top: 1px solid var(--ink); }
.flow li { padding: 24px 24px 0 0; }
.flow li + li { padding-left: 24px; border-left: 1px solid var(--line); }
.flow .n { font: 500 .8rem var(--mono); color: var(--clay); display: block; margin-bottom: 10px; }
.flow p { font-size: .92rem; color: #4a463e; }

/* ---------- form ---------- */
.order-grid { display: grid; grid-template-columns: 1fr 1.3fr; gap: clamp(32px, 6vw, 80px); align-items: start; }
.form { display: grid; gap: 20px; }
.row { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.f { display: grid; gap: 6px; font-size: .85rem; color: var(--muted); }
input, select, textarea {
  font: 1rem var(--gothic); color: var(--ink);
  background: var(--paper); border: 1px solid var(--line); border-radius: 0;
  padding: 12px 14px; width: 100%;
}
input:focus, select:focus, textarea:focus { outline: 2px solid var(--green-soft); outline-offset: -1px; border-color: var(--green-soft); }
.form .btn { justify-self: start; }
.hp { position: absolute; left: -9999px; width: 1px; height: 1px; opacity: 0; }
.notice { padding: 16px 18px; border-left: 3px solid var(--green); background: var(--paper); font-size: .95rem; }
.notice.err { border-color: var(--clay); }

/* ---------- faq ---------- */
.faq { border-top: 1px solid var(--ink); max-width: 820px; }
details { border-bottom: 1px solid var(--line); }
summary { cursor: pointer; list-style: none; padding: 20px 0; display: flex; justify-content: space-between; gap: 16px; font-weight: 500; }
summary::-webkit-details-marker { display: none; }
summary::after { content: "+"; font-family: var(--mono); color: var(--muted); }
details[open] summary::after { content: "−"; }
details p { padding: 0 0 22px; color: #4a463e; font-size: .95rem; }

/* ---------- footer ---------- */
.site-footer { background: var(--ink); color: var(--paper); padding: 56px 0; }
.site-footer .muted { color: #a29b8d; }
.footer-inner { display: flex; justify-content: space-between; align-items: flex-start; flex-wrap: wrap; gap: 28px; }
.footer-links { display: flex; flex-wrap: wrap; gap: 24px; }
.site-footer .footer-links a { color: #cfc8ba; }
.site-footer .footer-links a:hover { color: var(--paper); }
.site-footer .wordmark { margin-bottom: 6px; }

/* ---------- legal page ---------- */
.legal { padding-top: 64px; padding-bottom: 96px; max-width: 860px; }
.legal h1 { font-size: clamp(1.6rem, 3vw, 2.1rem); margin-bottom: 32px; }
.legal h2 { font-size: 1.4rem; margin: 64px 0 20px; }
.legal p { color: #4a463e; margin-bottom: 14px; }
.legal .todo { background: #f0dccf; padding: 0 4px; }

/* ---------- responsive ---------- */
@media (max-width: 900px) {
  .nav { display: none; }
  .hero, .build-grid, .order-grid { grid-template-columns: 1fr; }
  .three, .flow { grid-template-columns: 1fr 1fr; }
  .three article:nth-child(3), .flow li:nth-child(3) { border-left: 0; padding-left: 0; }
}
@media (max-width: 560px) {
  .three, .flow, .row { grid-template-columns: 1fr; }
  .three article + article, .flow li + li { border-left: 0; padding-left: 0; border-top: 1px solid var(--line); }
  .spec div { grid-template-columns: 1fr; gap: 2px; }
  .link-order { display: none; }
}