/* =========================================================
   BundAI — style.css
   softbank.jp / group.softbank の白背景・黒文字・シルバーアクセント、
   装飾を抑えた編集的なレイアウトに準拠
   ========================================================= */

:root{
  --bg: #ffffff;
  --bg-alt: #f5f5f6;
  --ink: #131416;
  --border: rgba(19,20,22,0.14);
  --border-soft: rgba(19,20,22,0.08);
  --text: #131416;
  --text-dim: rgba(19,20,22,0.66);
  --text-faint: rgba(19,20,22,0.42);
  --silver: #7c8288;
  --silver-deep: #5c6166;
  --font-jp: 'Noto Sans JP', -apple-system, BlinkMacSystemFont, 'Hiragino Sans', sans-serif;
  --header-h: 72px;
  --max: 1120px;
}

*, *::before, *::after{ box-sizing: border-box; }
html{ scroll-behavior: smooth; scroll-padding-top: var(--header-h); }
body{
  margin:0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-jp);
  line-height: 1.85;
  -webkit-font-smoothing: antialiased;
}
a{ color: inherit; text-decoration:none; }
img{ max-width:100%; display:block; }
ul{ list-style:none; margin:0; padding:0; }
h1,h2,h3{ margin:0; font-weight:700; }
p{ margin:0; }

.container{ max-width: var(--max); margin:0 auto; padding: 0 24px; }
.container-narrow{ max-width: 700px; }

.pc-only{ display:inline; }
@media (max-width:600px){ .pc-only{ display:none; } }

/* ---------- Header ---------- */
.site-header{
  position: fixed; top:0; left:0; right:0; z-index:100;
  height: var(--header-h);
  display:flex; align-items:center;
  background: #ffffff;
  border-bottom: 1px solid var(--border-soft);
}
.header-inner{
  width:100%; max-width: var(--max); margin:0 auto; padding: 0 24px;
  display:flex; align-items:center; justify-content:space-between;
}
.logo{
  font-weight:700; font-size: 19px;
  letter-spacing: 0.3px; color: var(--text);
}
.logo span{ color: var(--silver); }

.nav{ display:flex; align-items:center; gap: 36px; }
.nav a{
  font-size: 14px; font-weight:500; color: var(--text-dim);
  transition: color .2s ease; position:relative;
}
.nav a:not(.nav-cta):hover{ color: var(--ink); }
.nav-cta{
  padding: 8px 20px; border: 1px solid var(--ink);
  border-radius: 3px; color: var(--ink) !important;
  font-weight: 500;
  transition: background .2s ease, color .2s ease;
}
.nav-cta:hover{ background: var(--ink); color: #fff !important; }

.nav-toggle{
  display:none; flex-direction:column; justify-content:center; gap:5px;
  width: 32px; height:32px; background:none; border:none; cursor:pointer; padding:0;
}
.nav-toggle span{
  display:block; height:1.5px; width:100%; background: var(--text);
  transition: transform .3s ease, opacity .3s ease;
}
.nav-toggle.open span:nth-child(1){ transform: translateY(6.5px) rotate(45deg); }
.nav-toggle.open span:nth-child(2){ opacity:0; }
.nav-toggle.open span:nth-child(3){ transform: translateY(-6.5px) rotate(-45deg); }

/* ---------- Hero ---------- */
.hero{
  position: relative;
  overflow: hidden;
  min-height: 92vh;
  display:flex;
  align-items: flex-end;
  padding: calc(var(--header-h) + 60px) 24px 90px;
  text-align: left;
  background: var(--ink);
}
.hero-video{
  position:absolute; inset:0; z-index:0;
  width:100%; height:100%; object-fit:cover;
  filter: saturate(1.45) hue-rotate(-8deg) contrast(1.05) brightness(0.98);
}
.hero-content{
  position:relative; z-index:2; max-width: var(--max); margin: 0 auto; width:100%;
  text-shadow: 0 2px 16px rgba(0,0,0,0.4);
}
.hero-eyebrow{
  font-size: 12px; letter-spacing: 2px;
  color: rgba(255,255,255,0.82); font-weight:600; margin-bottom: 24px;
  padding-bottom: 14px; border-bottom: 1px solid rgba(255,255,255,0.32);
  display:inline-block;
}
.hero-title{
  font-size: clamp(38px, 7vw, 68px);
  line-height: 1.4;
  letter-spacing: 0.2px;
  margin-bottom: 44px;
  max-width: 20ch;
  color: #fff;
}
.hero-actions{ display:flex; gap:16px; flex-wrap:wrap; }
.hero .btn-primary{ background:#fff; color: var(--ink); }
.hero .btn-primary:hover{ background:#f0f0f0; }
.hero .btn-ghost{ border-color: rgba(255,255,255,0.55); color:#fff; }
.hero .btn-ghost:hover{ border-color:#fff; background: rgba(255,255,255,0.08); }

.btn{
  display:inline-flex; align-items:center; justify-content:center;
  padding: 13px 28px; border-radius: 3px; font-weight:500; font-size:14.5px;
  transition: background .2s ease, color .2s ease, border-color .2s ease;
  border: 1px solid transparent; cursor:pointer;
}
.btn-primary{ background: var(--ink); color:#fff; }
.btn-primary:hover{ background: #000; }
.btn-ghost{ border-color: var(--border); color: var(--text); }
.btn-ghost:hover{ border-color: var(--ink); }
.btn-wide{ width:100%; }

/* ---------- Sections ---------- */
.section{ padding: 100px 0; }
.section-alt{ background: var(--bg-alt); }
.section-eyebrow{
  font-size:12px; letter-spacing:2px;
  color: var(--silver-deep); font-weight:600; margin-bottom:12px;
}
.section-title{
  font-size: clamp(22px, 3vw, 30px);
  margin-bottom: 36px;
}

/* Service list */
.service-grid{
  display:grid; grid-template-columns: repeat(3, 1fr); gap: 0;
}
.service-card{
  padding: 8px 32px;
  border-right: 1px solid var(--border);
  position:relative;
}
.service-card:last-child{ border-right:none; }
.service-num{
  font-weight:600; font-size:13px;
  color: var(--silver); margin-bottom: 18px;
  letter-spacing: 1px;
}
.service-card h3{ font-size: 18px; margin-bottom: 16px; color: var(--ink); }
.service-text{ color: var(--text-dim); font-size: 14px; line-height:1.95; }

/* Strength */
.strength-grid{
  display:grid; grid-template-columns: repeat(3, 1fr); gap: 0;
}
.strength-item{
  padding: 8px 32px;
  border-right: 1px solid var(--border);
}
.strength-item:last-child{ border-right:none; }
.strength-num{
  font-weight:600; font-size: 11px;
  color: var(--silver); margin-bottom: 18px; letter-spacing:1px;
}
.strength-item h3{ font-size: 18px; margin-bottom: 16px; color: var(--ink); }
.strength-item p{ color: var(--text-dim); font-size: 14px; line-height:1.95; }

/* About / Profile */
.about-table{ width:100%; border-collapse: collapse; margin-bottom: 60px; }
.about-table tr{ border-bottom: 1px solid var(--border-soft); }
.about-table tr:first-child{ border-top: 1px solid var(--border); }
.about-table th, .about-table td{
  text-align:left; padding: 16px 12px; font-size: 14.5px; font-weight:400;
}
.about-table th{
  width: 140px; color: var(--text-faint); font-weight:600; letter-spacing:0.3px;
}
.about-table td a{ color: var(--silver-deep); }
.about-table td a:hover{ text-decoration: underline; }

.timeline-heading{
  font-size: 15px; font-weight:600; color: var(--ink);
  margin-bottom: 20px;
}
.timeline{ border-top: 1px solid var(--border); }
.timeline li{
  display:flex; flex-wrap:wrap; gap: 6px 24px;
  padding: 16px 4px; border-bottom: 1px solid var(--border-soft);
  font-size: 14.5px;
}
.timeline-period{
  width: 150px; flex-shrink:0; color: var(--text-faint); font-size: 13.5px;
}
.timeline-body{ color: var(--text); flex:1; min-width: 200px; }

/* Contact */
.contact-lead{
  color: var(--text-dim); margin-bottom: 44px; font-size: 14.5px;
}
.form-row{ margin-bottom: 22px; }
.form-row label{
  display:block; font-size: 13.5px; font-weight:600; margin-bottom: 8px;
  color: var(--text-dim);
}
.form-row label span{
  font-size: 11px; color: var(--silver-deep); border:1px solid var(--border);
  border-radius:3px; padding: 1px 6px; margin-left:8px; font-weight:500;
}
.form-row input,
.form-row select,
.form-row textarea{
  width:100%; padding: 12px 14px; border-radius: 3px;
  background: #fff; border: 1px solid var(--border);
  color: var(--text); font-family: var(--font-jp); font-size: 14.5px;
  outline:none; transition: border-color .2s ease;
}
.form-row input:focus,
.form-row select:focus,
.form-row textarea:focus{ border-color: var(--silver-deep); }
.form-row textarea{ resize: vertical; }
.form-note{ margin-top: 16px; font-size: 13.5px; color: var(--silver-deep); min-height: 20px; }
.contact-alt{
  margin-top: 36px; color: var(--text-faint); font-size: 13px;
}
.contact-alt a{ color: var(--silver-deep); }

/* Footer */
.site-footer{
  padding: 44px 0; border-top: 1px solid var(--border-soft);
}
.site-footer .container{ display:flex; flex-direction:column; align-items:center; justify-content:center; gap:14px; text-align:center; }
.site-footer p{ color: var(--text-faint); font-size: 12.5px; }

/* ---------- Responsive ---------- */
@media (max-width: 900px){
  .service-grid{ grid-template-columns: 1fr; }
  .service-card{ border-right:none; border-bottom: 1px solid var(--border); padding: 28px 4px; }
  .service-card:last-child{ border-bottom:none; }
  .strength-grid{ grid-template-columns: 1fr; }
  .strength-item{ border-right:none; border-bottom: 1px solid var(--border); padding: 24px 4px; }
  .strength-item:last-child{ border-bottom:none; }
}

@media (max-width: 760px){
  .nav{
    position:fixed; top: var(--header-h); left:0; right:0;
    flex-direction:column; align-items:flex-start; gap:0;
    background: #fff;
    border-bottom: 1px solid var(--border-soft);
    max-height: 0; overflow:hidden;
    transition: max-height .3s ease;
  }
  .nav.open{ max-height: 320px; }
  .nav a{ width:100%; padding: 16px 24px; border-bottom: 1px solid var(--border-soft); }
  .nav-cta{ margin: 14px 24px; border-radius: 3px; text-align:center; }
  .nav-toggle{ display:flex; }
  .about-table th{ width: 110px; font-size:13px; }
  .timeline-period{ width: 100%; }
}

@media (max-width: 480px){
  .hero{ min-height: 76vh; padding: calc(var(--header-h) + 40px) 20px 60px; }
  .section{ padding: 70px 0; }
}