/* accounting-research.co.jp
   依存ゼロ。ビルド不要。外部フォントを読み込まない
   (表示が速く、第三者にアクセス情報が渡らない)。

   見出しは明朝。Web フォントを取りに行かず、OS 搭載の明朝を使う。
   環境によって字面は変わるが、明朝であることは変わらない。 */

:root {
  --bg:        #faf8f4;
  --bg-sub:    #f2ede4;
  --fg:        #1c1a16;
  --fg-sub:    #4a453c;
  --fg-mute:   #8a8377;
  --line:      #e6e0d6;
  --line-soft: #ece7dd;
  --accent:    #6b5b3e;

  --serif: "Hiragino Mincho ProN", "Hiragino Mincho Pro", "Yu Mincho",
           YuMincho, "Noto Serif JP", "Source Han Serif JP",
           "Sans Serif", serif;
  --sans:  system-ui, -apple-system, "Segoe UI", "Hiragino Sans",
           "Hiragino Kaku Gothic ProN", "Noto Sans JP", Meiryo, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg:        #16150f;
    --bg-sub:    #1e1c15;
    --fg:        #ece7dd;
    --fg-sub:    #bab3a5;
    --fg-mute:   #8c8578;
    --line:      #2c2921;
    --line-soft: #23211a;
    --accent:    #c9ae7c;
  }
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 2.05;
  letter-spacing: 0.03em;
  font-feature-settings: "palt" 1;
  text-rendering: optimizeLegibility;
}

.wrap { max-width: 46rem; margin: 0 auto; padding: 0 1.75rem; }

/* --- ヘッダ --- */
.site-header {
  border-bottom: 1px solid var(--line);
  position: sticky; top: 0; z-index: 10;
  background: color-mix(in srgb, var(--bg) 92%, transparent);
  backdrop-filter: saturate(1.3) blur(10px);
}
.site-header .wrap {
  display: flex; align-items: baseline; gap: 1.5rem;
  padding: 1.125rem 1.75rem; flex-wrap: wrap;
}
.brand {
  font-family: var(--serif);
  font-weight: 700; font-size: 0.9375rem; letter-spacing: 0.08em;
  text-decoration: none; color: var(--fg);
}
.brand span {
  display: block; font-family: var(--sans);
  color: var(--fg-mute); font-weight: 400;
  font-size: 0.6875rem; letter-spacing: 0.14em;
}
.site-header nav { margin-left: auto; display: flex; gap: 1.5rem; font-size: 0.8125rem; }
.site-header nav a { color: var(--fg-sub); text-decoration: none; white-space: nowrap; }
.site-header nav a:hover { color: var(--accent); }

/* --- 見出し --- */
h1 {
  font-family: var(--serif);
  font-size: clamp(1.625rem, 5.5vw, 2.5rem);
  line-height: 1.7; letter-spacing: 0.05em;
  margin: 0 0 2.25rem; font-weight: 700;
}
h2 {
  font-family: var(--serif);
  font-size: 1.3125rem; font-weight: 700; letter-spacing: 0.12em;
  margin: 0 0 2.5rem;
}
h3 {
  font-family: var(--serif);
  font-size: 1.0625rem; font-weight: 700; margin: 0 0 0.75rem;
  letter-spacing: 0.05em;
}

p { margin: 0 0 1.25rem; color: var(--fg-sub); }
p.lead { color: var(--fg-sub); font-size: 1rem; line-height: 2.2; }
.note { font-size: 0.8125rem; color: var(--fg-mute); line-height: 1.9; }

section { padding: 4.25rem 0; border-top: 1px solid var(--line); }
.hero { padding: 5.5rem 0 4.5rem; border-top: 0; }

/* --- ヒーロー --- */
.hero-grid { display: grid; gap: 3rem; }
@media (min-width: 46rem) {
  .hero-grid { grid-template-columns: 1fr 13rem; gap: 3.5rem; align-items: start; }
}
.creds {
  border-left: 1px solid var(--line); padding-left: 1.5rem;
  font-size: 0.8125rem; line-height: 2.1; color: var(--fg-mute);
}
.creds dt {
  font-family: var(--serif); font-size: 0.875rem;
  color: var(--fg); margin-bottom: 0.5rem; font-weight: 700;
}
.creds dd { margin: 0; }

/* --- 一覧 --- */
.items { list-style: none; margin: 0; padding: 0; display: grid; gap: 2.875rem; }
.items p { margin: 0; font-size: 0.9375rem; }

/* --- 会社概要 --- */
.facts { border-collapse: collapse; width: 100%; font-size: 0.9375rem; }
.facts th, .facts td {
  text-align: left; vertical-align: top;
  padding: 0.9375rem 0; border-bottom: 1px solid var(--line-soft);
}
.facts th {
  width: 8rem; font-weight: 400; color: var(--fg); white-space: nowrap;
  font-size: 0.8125rem; letter-spacing: 0.08em; padding-top: 1.125rem;
}
.facts td { color: var(--fg-sub); }
.facts tr:last-child th, .facts tr:last-child td { border-bottom: 0; }

/* --- 連絡 --- */
a.cta {
  display: inline-block; margin: 0.5rem 0 1.75rem;
  font-family: var(--serif);
  border: 1px solid var(--fg); color: var(--fg);
  font-weight: 700; font-size: 0.9375rem; letter-spacing: 0.12em;
  text-decoration: none; padding: 0.9375rem 2.375rem;
}
a.cta:hover { background: var(--fg); color: var(--bg); }

/* --- フッタ --- */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 2.5rem 0 4rem;
  font-size: 0.75rem; letter-spacing: 0.08em; color: var(--fg-mute);
}
.site-footer p { color: inherit; margin: 0; }

:where(a):focus-visible {
  outline: 2px solid var(--accent); outline-offset: 3px;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}