/* Plasma コーポレートサイト v4 — ゼロベース再設計
   参照: nttd-mse / fivot / taiyo-kogyo 系の「写真＋短文＋ニュース」型
   原則: 語らない。1セクション1メッセージ。本文は50字以内。事実(実績・日付)で見せる。 */

:root {
  --ink:        #1A2436;
  --ink-soft:   #55607A;
  --ink-faint:  #98A0B0;
  --paper:      #FFFFFF;
  --paper-2:    #F5F5F2;
  --line:       #E8E8E4;
  --accent:     #1E6E64;

  --maxw: 1160px;
  --gutter: clamp(24px, 5vw, 60px);
  --serif: "Noto Serif JP", "Hiragino Mincho ProN", serif;
  --sans:  "Noto Sans JP", "Hiragino Kaku Gothic ProN", system-ui, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; overflow-x: clip; background: var(--ink); }
body {
  margin: 0; font-family: var(--sans); color: var(--ink); background: var(--paper);
  line-height: 1.9; font-size: 15px; -webkit-font-smoothing: antialiased; letter-spacing: .02em;
  overflow-x: clip;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

/* iOS15以前は overflow: clip 非対応 → html/body の clip 宣言が無効化されるため hidden で補う */
@supports not (overflow: clip) {
  html, body { overflow-x: hidden; }
}
.wrap { max-width: var(--maxw); margin: 0 auto; padding-inline: var(--gutter); }

/* ---------- header ---------- */
.site-header { position: sticky; top: 0; z-index: 50; background: rgba(255,255,255,.92); backdrop-filter: blur(10px); }
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; height: 76px; }
.logo { display: flex; align-items: center; }
.logo-img { height: 42px; width: auto; display: block; }
.nav { display: flex; gap: 32px; font-size: 13px; color: var(--ink); letter-spacing: .06em; font-weight: 500; }
.nav a:hover { color: var(--accent); }
.nav .cta-mini { color: var(--accent); font-weight: 700; }

/* ---------- mobile nav (hamburger) ---------- */
.nav-toggle { display: none; }
@media (max-width: 720px){
  .nav { display: none; }
  .logo-img { height: 32px; }

  .nav-toggle {
    display: inline-flex; align-items: center; justify-content: center;
    width: 44px; height: 44px; margin-right: -10px; padding: 0;
    background: none; border: 0; cursor: pointer; position: relative; z-index: 60;
    -webkit-tap-highlight-color: transparent;
  }
  .nav-toggle .bars { position: relative; display: block; width: 24px; height: 16px; }
  .nav-toggle .bars::before,
  .nav-toggle .bars::after,
  .nav-toggle .bars span {
    content: ""; position: absolute; left: 0; width: 100%; height: 2px;
    background: var(--ink); border-radius: 2px; transition: transform .28s ease, opacity .2s ease, top .28s ease;
  }
  .nav-toggle .bars::before { top: 0; }
  .nav-toggle .bars span { top: 7px; }
  .nav-toggle .bars::after { top: 14px; }
  .nav-toggle[aria-expanded="true"] .bars::before { top: 7px; transform: rotate(45deg); }
  .nav-toggle[aria-expanded="true"] .bars span { opacity: 0; }
  .nav-toggle[aria-expanded="true"] .bars::after { top: 7px; transform: rotate(-45deg); }
  .nav-toggle[aria-expanded="true"] .bars::before,
  .nav-toggle[aria-expanded="true"] .bars::after { background: #fff; }

  .mobile-menu {
    position: fixed; inset: 0; top: 0; right: 0; bottom: 0; left: 0; z-index: 55;
    background: var(--ink);
    display: flex; flex-direction: column; justify-content: center;
    padding: 0 var(--gutter);
    opacity: 0; visibility: hidden; transform: translateY(-8px);
    transition: opacity .3s ease, transform .3s ease, visibility 0s linear .3s;
  }
  .mobile-menu.open {
    opacity: 1; visibility: visible; transform: translateY(0);
    transition: opacity .3s ease, transform .3s ease;
  }

  /* メニュー用トップバー（ヘッダーと視覚的に連続） */
  .menu-topbar {
    position: absolute; top: 0; left: 0; right: 0;
    height: 76px; padding: 0 var(--gutter);
    display: flex; align-items: center; justify-content: space-between;
  }
  .menu-topbar .menu-logo { height: 32px; width: auto; display: block; }
  .menu-close {
    display: inline-flex; align-items: center; justify-content: center;
    width: 44px; height: 44px; margin-right: -10px; padding: 0;
    background: none; border: 0; cursor: pointer; position: relative;
    -webkit-tap-highlight-color: transparent;
  }
  .menu-close::before,
  .menu-close::after {
    content: ""; position: absolute; left: 50%; top: 50%;
    width: 24px; height: 2px; background: #fff; border-radius: 2px;
  }
  .menu-close::before { transform: translate(-50%, -50%) rotate(45deg); }
  .menu-close::after { transform: translate(-50%, -50%) rotate(-45deg); }

  .mobile-menu nav { display: flex; flex-direction: column; }
  .mobile-menu a {
    font-family: var(--serif); font-size: 22px; color: #fff; font-weight: 600;
    letter-spacing: .04em; padding: 14px 0; line-height: 1.4;
  }
  .mobile-menu a:active { color: var(--accent); }
  .mobile-menu a.cta-mini { color: var(--accent); }
  .mobile-menu .menu-sep { height: 1px; background: rgba(255,255,255,.16); margin: 18px 0; border: 0; }
  .mobile-menu a.ext { font-size: 18px; color: #C3CAD7; }
}
@media (min-width: 721px){ .mobile-menu { display: none; } }

/* ---------- buttons ---------- */
.btn { display: inline-block; font-size: 13.5px; font-weight: 600; letter-spacing: .08em; padding: 15px 40px; transition: .25s; }
.btn-primary { background: var(--ink); color: #fff; }
.btn-primary:hover { background: var(--accent); }

/* ---------- HERO: 全面写真＋一行 ---------- */
.hero-full { position: relative; height: min(82vh, 760px); min-height: 480px; background: var(--ink); overflow: hidden; }
.hero-full .bg { position: absolute; inset: 0; }
.hero-full .bg img { width: 100%; height: 100%; object-fit: cover; opacity: .72; }
.hero-full::after { content: ""; position: absolute; inset: 0;
  background: linear-gradient(15deg, rgba(16,24,42,.78) 22%, rgba(16,24,42,.25) 60%, rgba(16,24,42,.1)); }
.hero-full .inner { position: absolute; inset: 0; z-index: 2; display: flex; align-items: flex-end; }
.hero-full .inner .wrap { width: 100%; padding-bottom: clamp(48px, 8vw, 88px); }
.hero-full h1 {
  font-family: var(--serif); font-weight: 600; color: #fff;
  font-size: clamp(30px, 5.2vw, 56px); line-height: 1.4; letter-spacing: .02em; margin: 0 0 18px;
}
.hero-full .sub { color: rgba(255,255,255,.85); font-size: clamp(13.5px, 1.5vw, 15.5px); letter-spacing: .1em; margin: 0; }

/* ---------- section 共通 ---------- */
section { padding: clamp(72px, 10vw, 120px) 0; }
.sec-label { display: flex; align-items: baseline; gap: 16px; margin-bottom: clamp(36px, 5vw, 56px); }
.sec-label .en { font-size: clamp(22px, 2.6vw, 30px); font-weight: 700; letter-spacing: .06em; font-family: var(--sans); }
.sec-label .jp { font-size: 12.5px; color: var(--accent); font-weight: 600; letter-spacing: .12em; }

/* ---------- BUSINESS ---------- */
.biz-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: clamp(20px, 3vw, 36px); }
.biz { display: flex; flex-direction: column; }
.biz .media { aspect-ratio: 3 / 2; overflow: hidden; background: var(--ink); }
.biz .media img { width: 100%; height: 100%; object-fit: cover; filter: saturate(.9); transition: transform .5s ease; }
.biz:hover .media img { transform: scale(1.04); }
.biz .body { padding: 20px 0 0; }
.biz .domain { font-size: 12px; color: var(--ink-faint); letter-spacing: .12em; margin: 0 0 4px; }
.biz h3 { font-size: 18.5px; font-weight: 700; margin: 0 0 8px; letter-spacing: .03em; }
.biz p { font-size: 13.5px; color: var(--ink-soft); margin: 0 0 10px; line-height: 1.85; }
.biz .more { font-size: 12.5px; color: var(--accent); font-weight: 700; letter-spacing: .08em; }
.biz .more::after { content: "  →"; }
@media (max-width: 820px){ .biz-grid { grid-template-columns: 1fr; gap: 44px; } }

/* ---------- WORKS: 実名バンド ---------- */
.partners { background: var(--ink); color: #fff; padding: clamp(56px, 8vw, 80px) 0; }
.partners .wrap { display: flex; align-items: center; justify-content: space-between; gap: 32px; flex-wrap: wrap; }
.partners .lead-line { font-size: 13px; color: #A9B2C4; letter-spacing: .1em; margin: 0; }
.partners .names { display: flex; gap: clamp(28px, 5vw, 64px); flex-wrap: wrap; align-items: center; }
.partners .names span { font-family: var(--serif); font-size: clamp(17px, 2vw, 22px); font-weight: 600; letter-spacing: .04em; white-space: nowrap; }
.partners .names small { display: block; font-family: var(--sans); font-size: 11px; color: #8B94A8; letter-spacing: .08em; margin-top: 2px; }

/* ---------- NEWS ---------- */
.news { background: var(--paper-2); }
.news-list { margin: 0; padding: 0; list-style: none; max-width: 880px; }
.news-list li { border-bottom: 1px solid var(--line); }
.news-list li:first-child { border-top: 1px solid var(--line); }
.news-list a { display: grid; grid-template-columns: 110px 92px 1fr; gap: 18px; align-items: baseline; padding: 20px 4px; transition: background .2s; }
.news-list a:hover { background: rgba(30,110,100,.04); }
.news-list time { font-size: 12.5px; color: var(--ink-faint); letter-spacing: .06em; }
.news-list .cat { font-size: 11px; color: var(--accent); border: 1px solid currentColor; text-align: center; padding: 1px 0; letter-spacing: .08em; }
.news-list .t { font-size: 14px; color: var(--ink); }
@media (max-width: 640px){ .news-list a { grid-template-columns: 90px 1fr; } .news-list .cat { display: none; } }

/* ---------- COMPANY ---------- */
.about-table { width: 100%; border-collapse: collapse; max-width: 720px; }
.about-table th, .about-table td { text-align: left; padding: 17px 0; border-bottom: 1px solid var(--line); font-size: 14px; vertical-align: top; }
.about-table th { width: 150px; color: var(--ink-faint); font-weight: 500; }

/* ---------- CONTACT ---------- */
.contact-sec { background: var(--ink); color: #fff; text-align: center; }
.contact-sec .sec-label { justify-content: center; }
.contact-sec h2 { font-family: var(--serif); font-weight: 600; font-size: clamp(22px, 3vw, 32px); margin: 0 0 14px; }
.contact-sec p { color: #A9B2C4; font-size: 13.5px; margin: 0 0 34px; }
.contact-sec .btn-primary { background: #fff; color: var(--ink); }
.contact-sec .btn-primary:hover { background: var(--accent); color: #fff; }

/* ---------- footer ---------- */
.site-footer { background: var(--ink); color: #8B94A8; font-size: 12px; border-top: 1px solid rgba(255,255,255,.08); }
.site-footer .wrap { padding-block: 36px; display: flex; justify-content: space-between; align-items: center; gap: 16px; flex-wrap: wrap; }
.site-footer .logo-img { height: 32px; }

/* ============ 下層ページ ============ */
.breadcrumb { font-size: 12px; color: var(--ink-faint); padding-top: 24px; letter-spacing: .05em; }
.breadcrumb a:hover { color: var(--accent); }

.page-hero { padding: clamp(48px, 7vw, 80px) 0 clamp(40px, 5vw, 60px); }
.page-hero .tag { display: inline-block; font-size: 11px; letter-spacing: .22em; color: var(--accent); font-weight: 700; margin-bottom: 20px; }
.page-hero h1 { font-family: var(--serif); font-weight: 600; font-size: clamp(28px, 4.2vw, 44px); line-height: 1.4; margin: 0 0 16px; max-width: 22ch; }
.page-hero .sub { color: var(--ink-soft); max-width: 54ch; font-size: 14.5px; }

.page-hero.has-media { position: relative; color: #fff; background: var(--ink); overflow: hidden; padding-top: clamp(40px, 5vw, 56px); }
.page-hero.has-media .bg { position: absolute; inset: 0; }
.page-hero.has-media .bg img { width: 100%; height: 100%; object-fit: cover; opacity: .45; }
.page-hero.has-media::after { content: ""; position: absolute; inset: 0; background: linear-gradient(90deg, rgba(16,24,42,.9), rgba(16,24,42,.4)); }
.page-hero.has-media .wrap { position: relative; z-index: 2; }
.page-hero.has-media .tag { color: rgba(255,255,255,.8); }
.page-hero.has-media h1 { color: #fff; }
.page-hero.has-media .sub { color: #C3CAD7; }
.page-hero.has-media .breadcrumb { margin-bottom: clamp(28px, 4vw, 44px); }
.on-dark-breadcrumb { color: rgba(255,255,255,.6); }
.on-dark-breadcrumb a:hover { color: #fff; }

.section-head { max-width: 60ch; margin-bottom: clamp(36px, 5vw, 52px); }
.section-head .kicker { font-size: 11.5px; letter-spacing: .24em; color: var(--accent); font-weight: 700; margin: 0 0 14px; }
.section-head h2 { font-family: var(--serif); font-weight: 600; font-size: clamp(24px, 3.2vw, 34px); line-height: 1.5; margin: 0 0 14px; }
.section-head p { color: var(--ink-soft); margin: 0; font-size: 14px; }

.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: clamp(28px, 4vw, 48px); }
.step .n { color: var(--accent); font-size: 13px; font-weight: 700; letter-spacing: .1em; padding-top: 18px; border-top: 2px solid var(--ink); display: block; }
.step h4 { font-size: 16px; margin: 10px 0 6px; font-weight: 700; }
.step p { font-size: 13px; color: var(--ink-soft); margin: 0; line-height: 1.85; }
@media (max-width: 820px){ .steps { grid-template-columns: 1fr; gap: 30px; } }

.band { background: var(--ink); color: #fff; }
.band .wrap { display: grid; grid-template-columns: 1fr 1.15fr; gap: clamp(28px, 5vw, 64px); align-items: center; }
.band h2 { font-family: var(--serif); font-weight: 600; font-size: clamp(22px, 3vw, 32px); line-height: 1.5; margin: 0; }
.band p { color: #B4BCCB; margin: 0; font-size: 13.5px; line-height: 2; }
.band .accent-rule { width: 44px; height: 2px; background: var(--accent); margin-bottom: 22px; }
.band.has-media { position: relative; overflow: hidden; }
.band.has-media .bg { position: absolute; inset: 0; }
.band.has-media .bg img { width: 100%; height: 100%; object-fit: cover; opacity: .2; }
.band.has-media .wrap { position: relative; z-index: 2; }
@media (max-width: 820px){ .band .wrap { grid-template-columns: 1fr; gap: 22px; } }

.split { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(28px, 5vw, 64px); align-items: center; }
.split .fig { margin: 0; }
.split .fig img { width: 100%; display: block; }
.split figcaption { font-size: 11.5px; color: var(--ink-faint); margin-top: 10px; letter-spacing: .04em; }
@media (max-width: 820px){ .split { grid-template-columns: 1fr; } }

.prose { max-width: 60ch; }
.prose p { color: var(--ink-soft); font-size: 14px; }
.prose b { color: var(--ink); }
.note, .imgnote { font-size: 11.5px; color: var(--ink-faint); }

/* CTA strip（下層ページ末尾） */
.cta-strip { background: var(--paper-2); text-align: center; }
.cta-strip h2 { font-family: var(--serif); font-weight: 600; font-size: clamp(20px, 2.6vw, 28px); margin: 0 0 26px; }

/* ---------- FOUNDER ---------- */
.founder-grid { display: grid; grid-template-columns: 300px 1fr; gap: clamp(32px, 6vw, 72px); align-items: start; }
.founder-grid .photo img { width: 100%; display: block; }
.founder-grid .photo figcaption { font-size: 11.5px; color: var(--ink-faint); margin-top: 10px; letter-spacing: .05em; }
.founder .name { font-family: var(--serif); font-size: clamp(21px, 2.4vw, 26px); font-weight: 600; margin: 0 0 2px; }
.founder .role { font-size: 12px; color: var(--ink-faint); letter-spacing: .12em; margin: 0 0 22px; }
.founder .bio { font-size: 14px; color: var(--ink-soft); margin: 0 0 18px; max-width: 58ch; }
.founder .quote { font-family: var(--serif); font-size: clamp(16px, 1.8vw, 19px); color: var(--ink); line-height: 1.9; margin: 0 0 22px; max-width: 40ch; }
.media-line { font-size: 12px; color: var(--ink-faint); letter-spacing: .06em; margin: 0; padding-top: 16px; border-top: 1px solid var(--line); max-width: 58ch; }
.media-line b { color: var(--ink-soft); font-weight: 600; }
@media (max-width: 820px){ .founder-grid { grid-template-columns: 1fr; } .founder-grid .photo { max-width: 260px; } }

/* ---------- CORE TECHNOLOGY (v5) ---------- */
.core { background: var(--ink); color: #fff; }
.core .sec-label .en { color: #fff; }
.core-lead { font-family: var(--serif); font-weight: 600; font-size: clamp(24px, 3.4vw, 38px); line-height: 1.5; margin: 0 0 14px; }
.core-sub { color: #A9B2C4; font-size: 14px; margin: 0 0 clamp(40px, 6vw, 64px); }
.core-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: clamp(28px, 4vw, 56px); }
.core-item .en { display: block; color: var(--accent-l, #4FB3A6); font-size: 12px; font-weight: 700; letter-spacing: .26em; padding-top: 20px; border-top: 1px solid rgba(255,255,255,.25); }
.core-item h3 { font-family: var(--serif); font-size: 20px; font-weight: 600; margin: 12px 0 8px; color: #fff; }
.core-item p { font-size: 13px; color: #A9B2C4; margin: 0; line-height: 1.9; }
@media (max-width: 820px){ .core-grid { grid-template-columns: 1fr; gap: 30px; } }

/* BUSINESS 導入1行 */
.sec-lead { margin: calc(-1 * clamp(20px, 3vw, 36px)) 0 clamp(36px, 5vw, 52px); color: var(--ink-soft); font-size: 14px; }

/* ---------- CONTACT FORM ---------- */
.contact-form { max-width: 620px; margin: 0 auto; text-align: left; }
.contact-form .hp { display: none; }
.contact-form label { display: block; font-size: 12.5px; font-weight: 600; letter-spacing: .06em; color: #C3CAD7; margin-bottom: 18px; }
.contact-form .req { font-size: 10px; color: #fff; background: var(--accent); border-radius: 2px; padding: 1px 6px; margin-left: 6px; font-weight: 600; vertical-align: 1px; }
.contact-form input[type="text"], .contact-form input[type="email"], .contact-form textarea {
  display: block; width: 100%; margin-top: 8px;
  background: rgba(255,255,255,.06); border: 1px solid rgba(255,255,255,.22); border-radius: 2px;
  color: #fff; font-size: 14px; font-family: var(--sans); padding: 13px 14px; transition: border-color .2s, background .2s;
}
.contact-form input::placeholder, .contact-form textarea::placeholder { color: rgba(255,255,255,.35); }
.contact-form input:focus, .contact-form textarea:focus { outline: none; border-color: var(--accent); background: rgba(255,255,255,.09); }
.contact-form textarea { resize: vertical; min-height: 130px; }
.contact-form .row2 { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
@media (max-width: 640px){ .contact-form .row2 { grid-template-columns: 1fr; gap: 0; } }
.contact-form button { width: 100%; margin-top: 8px; border: none; cursor: pointer; background: #fff; color: var(--ink); }
.contact-form button:hover { background: var(--accent); color: #fff; }
.contact-form .alt { text-align: center; font-size: 12px; color: #8B94A8; margin: 18px 0 0; }
.contact-form .alt a { color: #C3CAD7; text-decoration: underline; }