/* ============================================================
   NAGI AI - Design System
   コンセプト:「現場に、凪を。」— 過剰な演出を削ぎ落とした、
   静かで信頼感のあるBtoBコンサルティングブランドのトーン。
   ============================================================ */

:root {
  /* Color */
  --color-ink: #10192b;        /* 見出し・本文の基調色(深い藍) */
  --color-navy: #14213d;       /* ヒーロー/フッターの背景 */
  --color-navy-soft: #1c2c4e;
  --color-paper: #f7f5f0;      /* ページ背景(生成りの白) */
  --color-paper-alt: #eeece4;
  --color-white: #ffffff;
  --color-line: #e3ded2;
  --color-teal: #3f8f83;       /* アクセント1: 凪いだ海の緑青 */
  --color-teal-dark: #2c6b61;
  --color-amber: #d99a3d;      /* アクセント2: 夜明けの陽 */
  --color-amber-dark: #b87c26;
  --color-text-muted: #5b6472;
  --color-text-on-navy: #d9dde6;

  /* Type */
  --font-base: "Hiragino Sans", "Noto Sans JP", "Yu Gothic", "Segoe UI", sans-serif;
  --font-serif: "Shippori Mincho", "Yu Mincho", serif;

  /* Layout */
  --max-width: 1120px;
  --radius: 10px;
  --shadow-card: 0 8px 24px rgba(16, 25, 43, 0.06);
  --shadow-card-hover: 0 14px 32px rgba(16, 25, 43, 0.1);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-base);
  background: var(--color-paper);
  color: var(--color-ink);
  line-height: 1.85;
  letter-spacing: 0.02em;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 12.5px;
  letter-spacing: 0.18em;
  font-weight: 700;
  color: var(--color-teal-dark);
  text-transform: uppercase;
}
.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--color-amber);
}

h1, h2, h3, h4 { line-height: 1.5; margin: 0; font-weight: 700; }
h2.section-title {
  font-size: clamp(24px, 3vw, 32px);
  margin: 10px 0 16px;
}
p.section-lead {
  color: var(--color-text-muted);
  max-width: 640px;
  margin: 0 0 40px;
}

.section-head { margin-bottom: 44px; }
.section-head.center { text-align: center; margin-left: auto; margin-right: auto; }
.section-head.center p.section-lead { margin-left: auto; margin-right: auto; }

section { padding: 88px 0; }
section.tight { padding: 56px 0; }
section.alt { background: var(--color-paper-alt); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 15px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
  white-space: nowrap;
}
.btn:hover { transform: translateY(-1px); }
.btn-primary {
  background: var(--color-amber);
  color: #241503;
  box-shadow: 0 10px 24px rgba(217, 154, 61, 0.35);
}
.btn-primary:hover { background: var(--color-amber-dark); }
.btn-outline {
  background: transparent;
  border-color: rgba(255,255,255,0.4);
  color: inherit;
}
.btn-outline:hover { background: rgba(255,255,255,0.08); }
.btn-ghost {
  background: var(--color-white);
  border-color: var(--color-line);
  color: var(--color-ink);
}
.btn-ghost:hover { border-color: var(--color-teal); color: var(--color-teal-dark); }
.btn-block { width: 100%; justify-content: center; }
.btn-sm { padding: 10px 18px; font-size: 13.5px; }

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(247, 245, 240, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-line);
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 18px;
  color: var(--color-ink);
}
.brand-mark {
  width: 34px; height: 34px;
  border-radius: 50%;
  background: radial-gradient(circle at 32% 30%, var(--color-teal) 0%, var(--color-navy) 70%);
  position: relative;
  flex-shrink: 0;
}
.brand-mark::after {
  content: "";
  position: absolute;
  left: 6px; right: 6px; top: 15px;
  height: 2px;
  border-radius: 2px;
  background: var(--color-amber);
  transform: rotate(-6deg);
}
.brand small {
  display: block;
  font-size: 10.5px;
  font-weight: 500;
  letter-spacing: 0.12em;
  color: var(--color-text-muted);
}

.nav-primary { display: flex; align-items: center; gap: 4px; }
.nav-primary a {
  padding: 10px 16px;
  font-size: 14.5px;
  font-weight: 600;
  color: var(--color-ink);
  border-radius: 8px;
}
.nav-primary a:hover { color: var(--color-teal-dark); }
.nav-primary a.is-active { color: var(--color-teal-dark); }
.nav-cta { display: flex; align-items: center; gap: 10px; margin-left: 12px; }

.nav-toggle {
  display: none;
  width: 40px; height: 40px;
  border-radius: 8px;
  border: 1px solid var(--color-line);
  background: var(--color-white);
  align-items: center;
  justify-content: center;
}
.nav-toggle span, .nav-toggle span::before, .nav-toggle span::after {
  content: "";
  display: block;
  width: 18px; height: 2px;
  background: var(--color-ink);
  position: relative;
  transition: 0.2s;
}
.nav-toggle span::before { position: absolute; top: -6px; }
.nav-toggle span::after { position: absolute; top: 6px; }

/* ---------- Hero ---------- */
.hero {
  background: linear-gradient(180deg, var(--color-navy) 0%, var(--color-navy-soft) 100%);
  color: var(--color-white);
  padding: 96px 0 110px;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  right: -120px; top: -160px;
  width: 480px; height: 480px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(63,143,131,0.35) 0%, rgba(63,143,131,0) 70%);
}
.hero .container { position: relative; }
.hero-tag {
  display: inline-block;
  padding: 7px 16px;
  border-radius: 999px;
  border: 1px solid rgba(255,255,255,0.25);
  font-size: 12.5px;
  letter-spacing: 0.1em;
  color: var(--color-text-on-navy);
  margin-bottom: 24px;
}
.hero h1 {
  font-size: clamp(32px, 4.4vw, 52px);
  letter-spacing: 0.03em;
  margin-bottom: 22px;
}
.hero h1 em {
  font-style: normal;
  color: var(--color-amber);
}
.hero-lead {
  font-size: 16.5px;
  color: var(--color-text-on-navy);
  max-width: 560px;
  margin-bottom: 36px;
}
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 56px; }
.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
  border-top: 1px solid rgba(255,255,255,0.15);
  padding-top: 32px;
}
.hero-stats .stat-num {
  font-size: clamp(22px, 2.6vw, 30px);
  font-weight: 700;
  color: var(--color-white);
}
.hero-stats .stat-num span { font-size: 14px; margin-left: 2px; color: var(--color-amber); }
.hero-stats .stat-label {
  font-size: 12.5px;
  color: var(--color-text-on-navy);
  margin-top: 4px;
}

/* ---------- Logos / trust strip ---------- */
.trust-strip { padding: 28px 0; border-bottom: 1px solid var(--color-line); }
.trust-strip .container {
  display: flex;
  align-items: center;
  gap: 24px;
  flex-wrap: wrap;
  justify-content: space-between;
}
.trust-strip .trust-label {
  font-size: 12.5px;
  color: var(--color-text-muted);
  letter-spacing: 0.08em;
  flex-shrink: 0;
}
.trust-tags { display: flex; gap: 10px; flex-wrap: wrap; }
.trust-tags span {
  font-size: 12.5px;
  padding: 6px 14px;
  border-radius: 999px;
  background: var(--color-paper-alt);
  color: var(--color-text-muted);
}

/* ---------- Issue list ---------- */
.issue-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}
.issue-card {
  background: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 26px 24px;
}
.issue-card .num {
  font-size: 13px;
  font-weight: 700;
  color: var(--color-amber-dark);
  margin-bottom: 10px;
  display: block;
}
.issue-card p { margin: 0; font-size: 15px; }
.issue-resolve {
  margin-top: 40px;
  text-align: center;
  font-size: 17px;
  font-weight: 700;
  padding: 26px;
  border-radius: var(--radius);
  background: var(--color-navy);
  color: var(--color-white);
}
.issue-resolve span { color: var(--color-amber); }

/* ---------- Cards / Grid ---------- */
.grid-3 { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 24px; }
.grid-2 { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 24px; }

.card {
  background: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow-card);
  transition: box-shadow 0.2s ease, transform 0.2s ease;
}
.card:hover { box-shadow: var(--shadow-card-hover); transform: translateY(-2px); }
.card .icon {
  width: 44px; height: 44px;
  border-radius: 12px;
  background: var(--color-paper-alt);
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 18px;
  font-size: 20px;
}
.card h3 { font-size: 17px; margin-bottom: 10px; }
.card p { color: var(--color-text-muted); font-size: 14.5px; margin: 0; }
.card ul { margin: 14px 0 0; padding-left: 18px; color: var(--color-text-muted); font-size: 14px; }
.card ul li { margin-bottom: 6px; }
.card .card-link {
  display: inline-block;
  margin-top: 16px;
  font-size: 13.5px;
  font-weight: 700;
  color: var(--color-teal-dark);
}

.badge {
  display: inline-block;
  font-size: 11.5px;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 999px;
  background: rgba(63,143,131,0.12);
  color: var(--color-teal-dark);
  margin-bottom: 12px;
}
.badge.amber { background: rgba(217,154,61,0.15); color: var(--color-amber-dark); }

/* ---------- Case studies ---------- */
.case-card {
  background: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-card);
}
.case-card .case-head {
  padding: 22px 24px;
  background: var(--color-paper-alt);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
}
.case-card .case-head strong { font-size: 15px; }
.case-card .case-head .tag {
  font-size: 12px;
  color: var(--color-text-muted);
}
.case-card .case-body { padding: 24px; }
.case-metric-row {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px dashed var(--color-line);
}
.case-metric { font-size: 13.5px; }
.case-metric b { display: block; font-size: 18px; color: var(--color-teal-dark); }

/* ---------- Testimonials ---------- */
.testi-card {
  background: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 28px;
}
.testi-card p.quote {
  font-size: 14.5px;
  color: var(--color-ink);
  margin: 0 0 18px;
}
.testi-card .who {
  font-size: 12.5px;
  color: var(--color-text-muted);
  border-top: 1px solid var(--color-line);
  padding-top: 14px;
}

/* ---------- FAQ ---------- */
.faq-item {
  border-bottom: 1px solid var(--color-line);
}
.faq-q {
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  padding: 22px 4px;
  font-size: 15.5px;
  font-weight: 700;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  color: var(--color-ink);
  font-family: inherit;
}
.faq-q .plus { color: var(--color-teal-dark); font-size: 20px; transition: transform 0.2s; }
.faq-item.is-open .faq-q .plus { transform: rotate(45deg); }
.faq-a {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.25s ease;
  color: var(--color-text-muted);
  font-size: 14.5px;
}
.faq-a-inner { padding: 0 4px 22px; }
.faq-item.is-open .faq-a { max-height: 320px; }

/* ---------- CTA band ---------- */
.cta-band {
  background: var(--color-navy);
  color: var(--color-white);
  border-radius: 20px;
  padding: 56px;
  text-align: center;
}
.cta-band h2 { font-size: clamp(22px, 3vw, 28px); margin-bottom: 14px; }
.cta-band p { color: var(--color-text-on-navy); margin-bottom: 30px; }
.cta-actions { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }

/* ---------- Footer ---------- */
.site-footer {
  background: var(--color-navy);
  color: var(--color-text-on-navy);
  padding: 64px 0 28px;
  margin-top: 40px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 32px;
  padding-bottom: 40px;
  border-bottom: 1px solid rgba(255,255,255,0.12);
}
.footer-grid h4 {
  font-size: 13px;
  color: var(--color-white);
  margin-bottom: 16px;
  letter-spacing: 0.05em;
}
.footer-grid ul { list-style: none; margin: 0; padding: 0; }
.footer-grid li { margin-bottom: 10px; font-size: 13.5px; }
.footer-grid a:hover { color: var(--color-amber); }
.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 24px;
  font-size: 12.5px;
  flex-wrap: wrap;
  gap: 10px;
  color: rgba(217,221,230,0.6);
}

/* ---------- Page header (sub pages) ---------- */
.page-header {
  background: var(--color-navy);
  color: var(--color-white);
  padding: 64px 0 48px;
}
.page-header .eyebrow { color: var(--color-amber); }
.page-header h1 { font-size: clamp(26px, 3.4vw, 36px); margin-top: 12px; }
.page-header p { color: var(--color-text-on-navy); margin-top: 14px; max-width: 620px; }
.breadcrumb {
  font-size: 12.5px;
  color: var(--color-text-on-navy);
  margin-bottom: 14px;
}
.breadcrumb a { color: var(--color-text-on-navy); border-bottom: 1px solid rgba(255,255,255,0.3); }

/* ---------- Table-ish spec list ---------- */
.spec-table { width: 100%; border-collapse: collapse; }
.spec-table th, .spec-table td {
  text-align: left;
  padding: 16px 18px;
  border-bottom: 1px solid var(--color-line);
  font-size: 14.5px;
  vertical-align: top;
}
.spec-table th {
  width: 180px;
  color: var(--color-text-muted);
  font-weight: 600;
}

/* ---------- Forms ---------- */
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.form-field { margin-bottom: 20px; }
.form-field.full { grid-column: 1 / -1; }
.form-field label {
  display: block;
  font-size: 13.5px;
  font-weight: 700;
  margin-bottom: 8px;
}
.form-field label .req {
  color: #b3492f;
  font-size: 11px;
  font-weight: 700;
  margin-left: 6px;
  border: 1px solid #b3492f;
  border-radius: 4px;
  padding: 1px 6px;
}
.form-field input,
.form-field select,
.form-field textarea {
  width: 100%;
  padding: 13px 14px;
  border: 1px solid var(--color-line);
  border-radius: 8px;
  font-family: inherit;
  font-size: 14.5px;
  background: var(--color-white);
}
.form-field textarea { resize: vertical; min-height: 110px; }
.form-note { font-size: 12.5px; color: var(--color-text-muted); margin-top: 18px; text-align: center; }
.form-success {
  display: none;
  background: rgba(63,143,131,0.12);
  border: 1px solid var(--color-teal);
  color: var(--color-teal-dark);
  border-radius: var(--radius);
  padding: 20px 22px;
  font-size: 14.5px;
  margin-bottom: 20px;
}
.form-success.is-visible { display: block; }

/* ---------- Blog ---------- */
.blog-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0,1fr));
  gap: 24px;
}
.post-card {
  background: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow-card);
}
.post-card .post-meta {
  font-size: 12px;
  color: var(--color-text-muted);
  display: flex;
  gap: 10px;
  margin-bottom: 12px;
}
.post-card h3 { font-size: 16px; margin-bottom: 10px; }
.post-card p { font-size: 13.5px; color: var(--color-text-muted); }
.post-card .tag {
  display: inline-block;
  font-size: 11px;
  padding: 3px 10px;
  border-radius: 999px;
  background: var(--color-paper-alt);
  color: var(--color-text-muted);
}

.post-body {
  max-width: 720px;
  margin: 0 auto;
  font-size: 16px;
}
.post-body h2 { font-size: 22px; margin: 40px 0 16px; }
.post-body h3 { font-size: 18px; margin: 32px 0 14px; }
.post-body p { margin: 0 0 20px; color: var(--color-ink); }
.post-body ul, .post-body ol { margin: 0 0 20px; padding-left: 22px; color: var(--color-ink); }
.post-body li { margin-bottom: 8px; }
.post-body blockquote {
  margin: 24px 0;
  padding: 18px 22px;
  border-left: 3px solid var(--color-teal);
  background: var(--color-paper-alt);
  color: var(--color-text-muted);
  border-radius: 0 8px 8px 0;
}
.post-hero {
  text-align: center;
  padding: 64px 0 40px;
  background: var(--color-navy);
  color: var(--color-white);
}
.post-hero .post-meta { justify-content: center; color: var(--color-text-on-navy); }
.post-hero h1 { font-size: clamp(24px, 3.2vw, 34px); margin: 14px auto 0; max-width: 760px; }

/* ---------- Utilities ---------- */
.mt-0 { margin-top: 0; }
.text-center { text-align: center; }
.stack { display: flex; flex-direction: column; gap: 14px; }

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
  .grid-3, .issue-grid, .footer-grid, .blog-grid { grid-template-columns: repeat(2, minmax(0,1fr)); }
  .hero-stats { grid-template-columns: repeat(2, minmax(0,1fr)); row-gap: 24px; }
  .form-grid { grid-template-columns: 1fr; }
}
@media (max-width: 880px) {
  .nav-primary, .nav-cta .btn-ghost { display: none; }
  .nav-toggle { display: flex; }
  section { padding: 64px 0; }
  .grid-3, .grid-2, .issue-grid, .footer-grid, .blog-grid { grid-template-columns: 1fr; }
  .cta-band { padding: 36px 22px; }
  body.nav-open .nav-primary {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 76px; left: 0; right: 0;
    background: var(--color-paper);
    border-bottom: 1px solid var(--color-line);
    padding: 12px 24px 20px;
  }
  body.nav-open .nav-cta { display: none; }
}