/* 解説「限られた経営資源でも、セキュリティは強化できる」共通 CSS
   トークンと部品は LP（security-gateway.html）のインライン CSS から切り出したもの。LP 側は変更しない。 */
:root {
  --paper: #F1EFE8;
  --paper-2: #FAF9F5;
  --ink: #2C2C2A;
  --ink-2: #5F5E5A;
  --ink-3: #888780;
  --line: #D3D1C7;
  --safe: #0F6E56;
  --alert: #A32D2D;
  --r1: #D85A30; --r2: #EF9F27; --r3: #97C459; --r4: #5DCAA5; --r5: #85B7EB; --r6: #AFA9EC; --r7: #ED93B1;
  --f-min: "Shippori Mincho", "Yu Mincho", "YuMincho", "Hiragino Mincho ProN", serif;
  --f-got: "Zen Kaku Gothic New", "Hiragino Sans", "Yu Gothic", "YuGothic", sans-serif;
  --f-lat: "Inter", "Zen Kaku Gothic New", "Hiragino Sans", "Yu Gothic", sans-serif;
  --pad-x: 24px;
  --part-y: 56px;
  --head-h: 64px;
}
@media (min-width: 960px) {
  :root { --pad-x: 40px; --part-y: 80px; --head-h: 80px; }
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-padding-top: calc(var(--head-h) + 16px); }
@media (prefers-reduced-motion: no-preference) { html { scroll-behavior: smooth; } }
html:has(dialog[open]) { overflow: hidden; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--f-got);
  font-weight: 400;
  font-size: 16px;
  line-height: 1.9;
  overflow-wrap: break-word;
}
@media (min-width: 640px) { body { font-size: 17px; } }
h1, h2 { font-family: var(--f-min); font-weight: 700; letter-spacing: .02em; margin: 0; color: var(--ink); }
h1 { font-size: clamp(32px, 5.6vw, 60px); line-height: 1.3; }
h2 { font-size: clamp(24px, 3.2vw, 32px); line-height: 1.45; text-wrap: balance; }
h1 .ph, h2 .ph { display: inline-block; max-width: 100%; }
h1 .nw { display: inline-block; max-width: 100%; }
h3 { font-family: var(--f-got); font-weight: 700; font-size: 18px; line-height: 1.6; margin: 0; }
p { margin: 0; }
a { color: inherit; }
ul, ol { margin: 0; padding: 0; }
:focus-visible { outline: 2px solid var(--ink); outline-offset: 3px; }

.vh {
  position: absolute !important; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}
.wrap { max-width: calc(1120px + var(--pad-x) * 2); margin: 0 auto; padding: 0 var(--pad-x); }

/* レインボー線（ヘッダー / h1 の上 / フッターの 3 か所だけ） */
.bow { display: flex; height: 2px; }
.bow i { flex: 1 1 0; }
.bow i:nth-child(1) { background: var(--r1); }
.bow i:nth-child(2) { background: var(--r2); }
.bow i:nth-child(3) { background: var(--r3); }
.bow i:nth-child(4) { background: var(--r4); }
.bow i:nth-child(5) { background: var(--r5); }
.bow i:nth-child(6) { background: var(--r6); }
.bow i:nth-child(7) { background: var(--r7); }

.eyebrow {
  font-family: "Inter", sans-serif; font-weight: 500; font-size: 12px; line-height: 1.4;
  letter-spacing: .25em; text-transform: uppercase; color: var(--ink-3); margin: 0 0 18px;
}
.note { font-size: 13px; line-height: 1.8; color: var(--ink-3); }
.num { font-family: var(--f-lat); font-weight: 600; letter-spacing: -.02em; }

/* ボタン */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 14px 28px; border-radius: 9999px; border: 1px solid transparent;
  font-family: var(--f-got); font-weight: 500; font-size: 15px; line-height: 1.5;
  text-decoration: none; cursor: pointer; transition: opacity .2s;
}
.btn:hover { opacity: .85; }
.btn-primary { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--ink); }
.actions { display: flex; flex-wrap: wrap; gap: 12px; }
@media (max-width: 639px) { .btn { width: 100%; } }

/* ヘッダー */
.site-head {
  position: fixed; top: 0; left: 0; right: 0; z-index: 50;
  background: var(--paper);
  background: color-mix(in srgb, var(--paper) 92%, transparent);
  border-bottom: 1px solid var(--line);
}
.head-in { display: flex; align-items: center; justify-content: space-between; gap: 24px; height: var(--head-h); }
.mark {
  display: inline-flex; flex-direction: column; gap: 6px; text-decoration: none; color: var(--ink);
  font-family: var(--f-min); font-weight: 700; font-size: 20px; line-height: 1.2; white-space: nowrap;
}
.mark small { margin-left: 10px; font-family: var(--f-got); font-weight: 500; font-size: 12px; letter-spacing: .04em; color: var(--ink-2); }
.mark .bow { width: 72px; }
.brand { display: flex; align-items: center; gap: 12px; }
.mark-sub { font-family: var(--f-got); font-weight: 500; font-size: 12px; letter-spacing: .04em; color: var(--ink-2); text-decoration: none; white-space: nowrap; }
.mark-sub:hover { text-decoration: underline; text-underline-offset: 6px; }
/* 360px 未満では「セキュリティ解説」を 2 行目に回し、メニューボタンを画面内に収める */
@media (max-width: 359px) { .mark small { display: block; margin: 2px 0 0; } }
.gnav ul { display: flex; gap: 22px; list-style: none; }
.gnav a { font-family: var(--f-lat); font-weight: 500; font-size: 14px; text-decoration: none; text-underline-offset: 6px; white-space: nowrap; }
.gnav a:hover, .gnav a[aria-current="page"] { text-decoration: underline; }
.head-cta { padding: 10px 22px; font-size: 14px; white-space: nowrap; }
.menu-btn {
  display: none; width: 44px; height: 44px; flex: none; padding: 0; cursor: pointer;
  border: 1px solid var(--ink); border-radius: 9999px; background: transparent;
  flex-direction: column; align-items: center; justify-content: center; gap: 5px;
}
.menu-btn span { display: block; width: 18px; height: 1px; background: var(--ink); }
/* ナビ 8 項目とボタンが 1 行に収まらない幅ではメニューに切り替える */
@media (max-width: 1079px) {
  .gnav, .head-cta { display: none; }
  html.js .menu-btn { display: inline-flex; }
}

/* メニュー（dialog） */
.menu {
  position: fixed; top: 0; right: 0; bottom: 0; left: auto; margin: 0;
  width: min(340px, 86vw); height: 100%; max-width: none; max-height: none;
  padding: 0; border: 0; border-left: 1px solid var(--line);
  background: var(--paper); color: var(--ink);
}
.menu::backdrop { background: rgba(44,44,42,.35); background: color-mix(in srgb, var(--ink) 35%, transparent); }
.menu-in { display: flex; flex-direction: column; height: 100%; padding: 12px 24px 32px; overflow-y: auto; }
.menu-top { display: flex; justify-content: flex-end; }
.menu-close {
  width: 44px; height: 44px; padding: 0; cursor: pointer; position: relative;
  border: 1px solid var(--ink); border-radius: 9999px; background: transparent;
}
.menu-close::before, .menu-close::after {
  content: ""; position: absolute; left: 12px; right: 12px; top: 50%; height: 1px; background: var(--ink);
}
.menu-close::before { transform: rotate(45deg); }
.menu-close::after { transform: rotate(-45deg); }
.menu ul { list-style: none; margin: 20px 0 32px; border-top: 1px solid var(--line); }
.menu li a { display: block; padding: 14px 0; border-bottom: 1px solid var(--line); font-weight: 500; font-size: 16px; line-height: 1.6; text-decoration: none; }
.menu li a[aria-current="page"] { text-decoration: underline; text-underline-offset: 6px; }
.menu li .num { display: inline-block; min-width: 2.2em; color: var(--ink-3); }
.menu .btn { width: 100%; }

/* ページの頭: 英字ラベル → レインボー線 → h1 → 費用の印 → リード */
.page-head { padding: calc(var(--head-h) + 56px) 0 56px; }
.page-head .eyebrow { margin: 0; }
.head-bow { width: 120px; margin: 22px 0 26px; }
.page-head .lead { margin-top: 24px; max-width: 34em; }
.cost { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 12px; margin-top: 24px; }
.cost-note { font-size: 14px; line-height: 1.7; color: var(--ink-2); }
@media (min-width: 960px) { .page-head { padding: calc(var(--head-h) + 88px) 0 72px; } }

/* 費用の印（無料 = --safe、有料 = --alert の枠線ピル） */
.pill {
  display: inline-block; border: 1px solid currentColor; border-radius: 9999px; padding: 3px 14px;
  font-family: var(--f-got); font-weight: 500; font-size: 13px; line-height: 1.6; white-space: nowrap;
}
.pill-free { color: var(--safe); }
.pill-paid { color: var(--alert); }

/* 本文の区切り */
.part { padding: var(--part-y) 0; border-top: 1px solid var(--line); }
.part > .wrap > h2 { max-width: 38em; margin-bottom: 28px; }
.prose { max-width: 38em; }
.prose > p + p, .prose > p + ul, .prose > ul + p, .prose > p + ol, .prose > ol + p { margin-top: 1.2em; }
.prose a { text-underline-offset: 4px; }
.prose-after { margin-top: 32px; }

/* 出典番号 */
.cite { font-family: var(--f-lat); font-weight: 500; font-size: 11px; line-height: 0; vertical-align: super; margin-left: 1px; }
.cite a { color: var(--ink-2); text-decoration: none; padding: 0 1px; }
.cite a:hover { text-decoration: underline; }

/* 罫線区切りのリスト */
.rule-list { list-style: none; border-top: 1px solid var(--line); }
.rule-list > li { padding: 20px 0; border-bottom: 1px solid var(--line); }

/* 番号付きの罫線リスト（左に番号、右に見出しと本文） */
.numlist { list-style: none; border-top: 1px solid var(--line); max-width: 38em; }
.numlist > li { display: grid; grid-template-columns: 48px minmax(0, 1fr); column-gap: 16px; padding: 24px 0; border-bottom: 1px solid var(--line); }
.numlist .n { font-size: 26px; line-height: 1.35; color: var(--ink-3); }
.numlist h2, .numlist h3 { font-family: var(--f-got); font-weight: 700; font-size: 19px; line-height: 1.6; letter-spacing: 0; margin-bottom: 8px; }
.numlist.is-tight > li { padding: 16px 0; }
.numlist.is-tight .n { font-size: 20px; line-height: 1.7; }
@media (min-width: 640px) {
  .numlist > li { grid-template-columns: 64px minmax(0, 1fr); column-gap: 20px; padding: 28px 0; }
  .numlist .n { font-size: 32px; line-height: 1.2; }
}
.part .numlist + p, .part .prose + .numlist, .part .numlist + .prose { margin-top: 32px; }

/* 数字の帯 */
.stats { background: var(--paper-2); border-top: 1px solid var(--line); padding: 48px 0; }
.stats ul { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); list-style: none; }
.stats li { padding: 4px 24px; border-left: 1px solid var(--line); }
.stats li:first-child { border-left: 0; padding-left: 0; }
.stats .num { display: block; font-size: clamp(40px, 6vw, 64px); line-height: 1.1; white-space: nowrap; }
.stats .u { font-family: var(--f-got); font-weight: 500; font-size: .36em; letter-spacing: 0; }
.stats p { margin-top: 10px; font-size: 13px; line-height: 1.7; color: var(--ink-2); }
.stats .note { margin-top: 28px; }
@media (max-width: 959px) {
  .stats ul { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .stats li { padding: 20px 0 20px 20px; }
  .stats li:nth-child(odd) { border-left: 0; padding-left: 0; }
  .stats li:nth-child(n+3) { border-top: 1px solid var(--line); }
}

/* 被害の連鎖（4 段階。PC は横並び、スマホは縦） */
.chain { list-style: none; display: grid; grid-template-columns: minmax(0, 1fr); margin-top: 40px; }
.chain > li { display: grid; grid-template-columns: 48px minmax(0, 1fr); column-gap: 16px; position: relative; padding-bottom: 32px; }
.chain > li:last-child { padding-bottom: 0; }
.chain > li:not(:last-child)::before {
  content: ""; position: absolute; left: 15px; top: 40px; bottom: 6px; width: 1px; background: var(--line);
}
.chain-no { font-size: 26px; line-height: 1.3; color: var(--ink-3); }
.chain h3 { font-size: 18px; margin-bottom: 6px; }
.chain p { font-size: 15px; line-height: 1.85; color: var(--ink-2); }
.chain > li:last-child .chain-no { color: var(--alert); }
@media (min-width: 900px) {
  .chain { grid-template-columns: repeat(4, minmax(0, 1fr)); column-gap: 28px; }
  .chain > li { display: block; padding-bottom: 0; }
  .chain > li:not(:last-child)::before { content: none; }
  .chain-no { display: flex; align-items: center; gap: 14px; margin-bottom: 18px; }
  .chain > li:not(:last-child) .chain-no::after { content: ""; flex: 1; height: 1px; background: var(--line); margin-right: -28px; }
}

/* 表（罫線は横線のみ） */
.tbl-hint { display: none; margin-bottom: 8px; }
.tbl-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; border-radius: 4px; }
.tbl { width: 100%; border-collapse: collapse; font-size: 15px; line-height: 1.7; }
.tbl th, .tbl td { text-align: left; vertical-align: top; padding: 16px 16px 16px 0; border-bottom: 1px solid var(--line); }
.tbl thead th { font-weight: 500; font-size: 13px; color: var(--ink-2); padding-top: 12px; padding-bottom: 12px; border-top: 1px solid var(--line); }
.tbl tbody th { font-weight: 500; white-space: nowrap; }
.prose .tbl-wrap { margin: 28px 0; }

/* 開閉の「＋」（details を使うときの共通の型。LP と同じ） */
summary::-webkit-details-marker { display: none; }
.plus { list-style: none; cursor: pointer; display: flex; justify-content: space-between; align-items: center; gap: 16px; padding: 14px 0; font-weight: 500; font-size: 14px; color: var(--ink-2); }
.plus::after { content: "＋"; flex: none; line-height: 1; color: var(--ink-2); transition: transform .25s ease; }
details[open] > summary.plus::after { transform: rotate(45deg); }

/* 多層防御の図 */
.fig { margin: 40px 0 0; max-width: 560px; }
.layer-art { display: block; width: 100%; height: auto; }
.layer-art .ln { fill: none; stroke: var(--ink-2); stroke-width: 1.5; stroke-linecap: round; stroke-linejoin: round; }
.layer-art .t { fill: var(--ink); font-family: var(--f-got); font-weight: 500; font-size: 14px; }
.layer-art .t-sub { fill: var(--ink-2); font-family: var(--f-got); font-size: 12px; }
.layer-art .d-free { fill: var(--safe); }
.layer-art .d-paid { fill: var(--alert); }
.layer-art .d-n { fill: var(--paper); font-family: var(--f-lat); font-weight: 600; font-size: 10px; }
.fig figcaption { display: flex; flex-wrap: wrap; gap: 4px 20px; margin-top: 16px; font-size: 13px; line-height: 1.7; color: var(--ink-2); }
.key { display: inline-flex; align-items: center; gap: 8px; }
.key::before { content: ""; width: 10px; height: 10px; border-radius: 50%; background: var(--safe); }
.key.is-paid::before { background: var(--alert); }

/* 6 つの層（導線） */
.layers { max-width: 52em; }
.layers > li { padding: 0; }
.layer-link { display: grid; grid-template-columns: 56px minmax(0, 1fr) auto; column-gap: 20px; align-items: start; padding: 24px 0; text-decoration: none; }
.layer-link .n { font-size: 32px; line-height: 1.2; color: var(--ink-3); }
.layer-link h3 { font-size: 19px; }
.layer-link h3 span { text-decoration: underline; text-decoration-color: var(--line); text-underline-offset: 6px; }
.layer-link:hover h3 span { text-decoration-color: var(--ink); }
.layer-link p { margin-top: 4px; color: var(--ink-2); }
.layer-link .cost { margin-top: 0; justify-content: flex-end; }
@media (max-width: 719px) {
  .layer-link { grid-template-columns: 44px minmax(0, 1fr); column-gap: 14px; }
  .layer-link .n { font-size: 24px; line-height: 1.5; }
  .layer-link .cost { grid-column: 2; justify-content: flex-start; margin-top: 12px; }
}

/* 06 の層の一覧 */
.toc-list { max-width: 38em; }
.toc-list > li { padding: 14px 0; }
.toc-list a { text-underline-offset: 5px; }
.toc-list .num { display: inline-block; min-width: 2.4em; color: var(--ink-3); }

/* Rainbow Gateway への導線（03 と 04 の末尾に 1 か所ずつ） */
.guide-cta { background: var(--paper-2); border: 1px solid var(--line); border-radius: 4px; padding: 40px 24px; max-width: 52em; }
.guide-cta h2 { margin-bottom: 16px; }
.guide-cta p { max-width: 38em; }
.guide-cta .actions { margin-top: 28px; }
@media (min-width: 640px) { .guide-cta { padding: 48px 48px; } }

/* 出典 */
.sources { background: var(--paper-2); border-top: 1px solid var(--line); padding: 48px 0; }
.sources h2 { font-family: var(--f-got); font-size: 15px; font-weight: 700; letter-spacing: .04em; margin-bottom: 12px; }
.sources ol { padding-left: 2.2em; max-width: 60em; }
.sources li { font-size: 13px; line-height: 1.8; color: var(--ink-2); }
.sources li + li { margin-top: 10px; }
.sources a { display: block; overflow-wrap: anywhere; color: var(--ink-2); }
.sources li:target { color: var(--ink); }

/* 前へ / 次へ */
.pager { border-top: 1px solid var(--line); padding: 48px 0 56px; }
.pager-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.pager-grid a, .pager-grid .pager-none { display: block; padding: 22px 0; text-decoration: none; }
.pager-grid .next { text-align: right; border-left: 1px solid var(--line); padding-left: 20px; }
.pager-grid .prev { padding-right: 20px; }
.pager-label { display: block; font-size: 13px; line-height: 1.6; color: var(--ink-3); }
.pager-title { display: block; margin-top: 4px; font-family: var(--f-min); font-weight: 700; font-size: 18px; line-height: 1.5; }
.pager-grid a:hover .pager-title { text-decoration: underline; text-underline-offset: 5px; }
.pager-toc { margin-top: 20px; font-size: 15px; }
.pager-toc a { text-underline-offset: 5px; }
@media (max-width: 639px) {
  .pager-grid { grid-template-columns: minmax(0, 1fr); }
  .pager-grid .next { border-left: 0; border-top: 1px solid var(--line); padding-left: 0; }
  .pager-grid .prev { padding-right: 0; }
  .pager-grid .pager-none { display: none; }
}

/* 事例の年表 */
.cases-wrap { margin-top: 8px; }
.tbl.cases { min-width: 1000px; font-size: 14px; }
.tbl.cases td:nth-child(4) { min-width: 16em; }
.tbl.cases td:last-child a { overflow-wrap: anywhere; font-family: var(--f-lat); font-size: 13px; color: var(--ink-2); }
.tbl.cases .num { font-weight: 500; letter-spacing: 0; white-space: nowrap; }
@media (max-width: 1079px) { .cases-hint { display: block; } }
.cases-note { margin-top: 24px; max-width: 60em; }

/* フッター */
.foot { background: var(--paper-2); }
.foot-in { padding-top: 56px; padding-bottom: 40px; }
.foot .mark { display: inline-block; }
.foot-nav ul { display: flex; flex-wrap: wrap; gap: 8px 22px; list-style: none; margin: 22px 0 28px; }
.foot-nav a { font-weight: 500; font-size: 14px; text-decoration: none; }
.foot-nav a:hover { text-decoration: underline; text-underline-offset: 6px; }
/* フッターの情報セキュリティ基本方針（盾のマーク付き。リンクだけでなく姿勢を見せる） */
.foot-sec {
  display: flex; align-items: center; gap: 18px; max-width: 680px; margin: 0 0 28px; padding: 18px 22px;
  border: 1px solid var(--line); border-radius: 4px; background: var(--paper); color: var(--ink); text-decoration: none;
  transition: border-color .2s;
}
.foot-sec:hover { border-color: var(--ink); }
.foot-sec-icon { flex: none; width: 40px; height: 47px; fill: none; stroke-linecap: round; stroke-linejoin: round; }
.foot-sec-icon .shield { stroke: var(--ink); stroke-width: 2; }
.foot-sec-icon .chk { stroke: var(--safe); stroke-width: 3; }
.foot-sec-txt { display: flex; flex-direction: column; min-width: 0; }
.foot-sec-label { font-family: var(--f-lat); font-weight: 500; font-size: 11px; line-height: 1.6; letter-spacing: .25em; color: var(--ink-3); }
.foot-sec-title { font-family: var(--f-min); font-weight: 700; font-size: 18px; line-height: 1.5; }
.foot-sec-desc { margin-top: 2px; font-size: 13px; line-height: 1.7; color: var(--ink-2); }
.foot-sec-arrow { flex: none; margin-left: auto; font-family: var(--f-lat); color: var(--ink-3); transition: transform .2s, color .2s; }
.foot-sec:hover .foot-sec-arrow { transform: translateX(3px); color: var(--ink); }
@media (max-width: 479px) { .foot-sec { gap: 14px; padding: 16px; } .foot-sec-icon { width: 32px; height: 38px; } .foot-sec-arrow { display: none; } }
@media (prefers-reduced-motion: reduce) { .foot-sec, .foot-sec-arrow { transition: none; } }
.company { font-size: 14px; line-height: 1.9; color: var(--ink-2); }
.foot-note { margin-top: 20px; }
.copyright { margin-top: 8px; font-family: var(--f-lat); }

@media (prefers-reduced-motion: reduce) {
  .btn, .plus::after { transition: none; }
}
@media print {
  .site-head, .menu { display: none; }
  .page-head { padding-top: 24px; }
}