/* 株式会社MUT 公式サイト（叩き台） */
:root {
  --bg: #0e0e0f;          /* 黒 */
  --bg-alt: #17171a;      /* チャコール */
  --line: #2a2a2e;
  --text: #f4f3f0;        /* 白文字 */
  --muted: #a3a29e;
  --accent: #d8a64a;      /* アクセントは1色のみ */
  --wrap: 1120px;
  --gutter: clamp(20px, 5vw, 48px);
  --font-en: "Inter Tight", "Helvetica Neue", Arial, sans-serif;
  --font-ja: "Noto Sans JP", "Hiragino Sans", "Hiragino Kaku Gothic ProN", Meiryo, sans-serif;
}

*,
*::before,
*::after { box-sizing: border-box; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-ja);
  font-size: 16px;
  line-height: 1.85;
  letter-spacing: 0.02em;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, p, ol, ul, dl, dd, figure { margin: 0; }
ol, ul { padding: 0; list-style: none; }
a { color: inherit; }
a:focus-visible, .btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }

.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 var(--gutter); }

.skip { position: absolute; left: -9999px; }
.skip:focus { left: 16px; top: 16px; z-index: 100; background: var(--text); color: var(--bg); padding: 8px 12px; }

/* ヘッダー */
.site-header {
  position: sticky; top: 0; z-index: 10;
  background: rgba(14, 14, 15, 0.88);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; gap: 16px; }
.logo { display: block; line-height: 0; }
.logo img { display: block; height: 40px; width: auto; }
.nav { display: flex; gap: clamp(14px, 3vw, 32px); font-family: var(--font-en); font-weight: 500; font-size: 14px; letter-spacing: 0.06em; }
.nav a { text-decoration: none; color: var(--muted); transition: color .2s; }
.nav a:hover { color: var(--text); }
.nav .nav-cta { color: var(--accent); }

/* ボタン */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 48px; padding: 0 28px;
  background: var(--text); color: var(--bg);
  font-weight: 700; font-size: 15px; letter-spacing: 0.04em;
  text-decoration: none; border: 1px solid var(--text);
  transition: background .2s, color .2s;
}
.btn:hover { background: transparent; color: var(--text); }
.btn--outline { background: transparent; color: var(--text); }
.btn--outline:hover { background: var(--text); color: var(--bg); }
.btn--large { min-height: 56px; font-size: 16px; }

/* ヒーロー */
.hero {
  padding: clamp(72px, 14vw, 176px) 0 clamp(160px, 22vw, 280px);
  /* 文字の視認性優先：左と上を暗く落とし、下部の光の軌跡だけを見せる */
  background:
    linear-gradient(to right, rgba(14, 14, 15, 0.7) 0%, rgba(14, 14, 15, 0.25) 60%, rgba(14, 14, 15, 0) 100%),
    linear-gradient(to bottom, rgba(14, 14, 15, 0.6) 0%, rgba(14, 14, 15, 0.35) 55%, rgba(14, 14, 15, 0) 85%, var(--bg) 100%),
    url("../assets/hero-abstract-light-trails.jpg") center bottom / cover no-repeat,
    var(--bg);
}
@media (max-width: 720px) {
  /* 縦長画面では左側の明るい交差部分が切れないよう寄せる */
  .hero { background-position: 0 0, 0 0, 22% bottom, 0 0; }
}
.eyebrow { font-family: var(--font-en); font-size: 12px; font-weight: 500; letter-spacing: 0.2em; text-transform: uppercase; color: var(--muted); margin-bottom: 20px; }
.hero-title {
  font-family: var(--font-en); font-weight: 800;
  font-size: clamp(44px, 10vw, 136px); line-height: 1.0; letter-spacing: -0.02em;
}
.hero-company { margin: 20px 0 32px; font-weight: 700; font-size: clamp(16px, 2vw, 20px); letter-spacing: 0.12em; }
.hero-company::before { content: ""; display: inline-block; width: 28px; height: 2px; background: var(--accent); vertical-align: middle; margin-right: 12px; }

/* セクション共通 */
.section { padding: clamp(72px, 11vw, 128px) 0; border-top: 1px solid var(--line); }
.section--alt { background: var(--bg-alt); }
.section-head { margin-bottom: clamp(32px, 5vw, 56px); }
.section-en { font-family: var(--font-en); font-weight: 800; font-size: clamp(32px, 5.5vw, 56px); line-height: 1; letter-spacing: -0.01em; }
.section-title { margin-top: 12px; font-size: 14px; font-weight: 500; color: var(--muted); letter-spacing: 0.16em; }

/* 事業内容 */
.services { display: grid; gap: 0; counter-reset: svc; border-top: 1px solid var(--line); }
.services li { counter-increment: svc; display: grid; grid-template-columns: 48px 1fr; column-gap: 12px; padding: 22px 0; border-bottom: 1px solid var(--line); }
.services li::before { content: counter(svc, decimal-leading-zero); grid-row: span 2; font-family: var(--font-en); font-weight: 700; font-size: 14px; color: var(--accent); padding-top: 4px; }
.services h3 { font-size: clamp(17px, 2vw, 20px); font-weight: 700; line-height: 1.6; }
.services p { color: var(--muted); font-size: 15px; }
@media (min-width: 900px) {
  .services { grid-template-columns: 1fr 1fr; column-gap: 56px; border-top: 0; }
  .services li:nth-child(-n+2) { border-top: 1px solid var(--line); }
}

/* 取引実績 */
.clients { display: grid; grid-template-columns: 1fr; column-gap: clamp(32px, 5vw, 64px); border-top: 1px solid var(--line); }
.clients li { position: relative; padding: 22px 0 22px 28px; border-bottom: 1px solid var(--line); font-weight: 700; font-size: clamp(15px, 1.8vw, 17px); letter-spacing: 0.04em; }
.clients li::before { content: ""; position: absolute; left: 0; top: calc(22px + 0.85em); width: 12px; height: 2px; background: var(--accent); }
@media (min-width: 720px) {
  .clients { grid-template-columns: repeat(2, 1fr); border-top: 0; }
  .clients li:nth-child(-n+2) { border-top: 1px solid var(--line); }
}

/* プロフィール・会社概要 */
.about { display: grid; gap: clamp(40px, 6vw, 72px); }
.profile-name { font-size: clamp(24px, 3vw, 30px); font-weight: 900; letter-spacing: 0.08em; line-height: 1.4; margin-bottom: 8px; }
.profile-name span { display: block; font-family: var(--font-en); font-weight: 500; font-size: 14px; letter-spacing: 0.16em; color: var(--muted); }
.profile-role { font-weight: 700; margin-bottom: 16px; }
.profile p:last-child { color: #d6d5d1; }
.company { border-top: 1px solid var(--line); }
.company div { display: grid; grid-template-columns: 6.5em 1fr; gap: 16px; padding: 16px 0; border-bottom: 1px solid var(--line); }
.company dt { color: var(--muted); font-size: 14px; padding-top: 2px; }
.company a { text-decoration: underline; text-underline-offset: 4px; text-decoration-color: var(--accent); }
@media (min-width: 900px) {
  .about { grid-template-columns: 1fr 1fr; align-items: start; }
}

/* 問い合わせ */
.section--contact { background: var(--bg-alt); }
.contact-lead { margin-bottom: 32px; color: #d6d5d1; }
.contact-actions { display: flex; flex-direction: column; gap: 16px; }
.contact-actions .btn { width: 100%; }
@media (min-width: 640px) {
  .contact-actions { flex-direction: row; flex-wrap: wrap; }
  .contact-actions .btn { width: auto; }
}

/* フッター */
.site-footer { border-top: 1px solid var(--line); padding: 32px 0; }
.footer-inner { display: flex; justify-content: space-between; align-items: center; }
.footer-logo { line-height: 0; }
.footer-logo img { display: block; height: 28px; width: auto; }
.copyright { font-family: var(--font-en); font-size: 12px; color: var(--muted); letter-spacing: 0.08em; }

/* スマートフォン */
@media (max-width: 520px) {
  .nav { gap: 14px; font-size: 13px; }
}