/* =========================================================
   株式会社デルタスタート — Fable 5版
   ダーク×ディープブルー、Δ（デルタ）モチーフのワンページ構成
   ========================================================= */

:root {
  --ink: #070b14;          /* ベースの闇（青みの黒） */
  --ink-2: #0b111f;        /* セクション交互の面 */
  --ink-3: #101828;        /* カード面 */
  --line: rgba(148, 163, 198, 0.16);
  --text: #e9edf6;
  --muted: #97a3bd;
  --accent: #4d8dff;       /* デルタブルー */
  --accent-soft: #8ab4ff;
  --en: 'Space Grotesk', sans-serif;
  --ja: 'Noto Sans JP', sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--ja);
  background: var(--ink);
  color: var(--text);
  line-height: 1.8;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

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

.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- 出現アニメーション ---------- */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.is-visible { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}

/* ---------- ヘッダー ---------- */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  transition: background 0.3s ease, border-color 0.3s ease;
  border-bottom: 1px solid transparent;
}
.site-header.is-scrolled {
  background: rgba(7, 11, 20, 0.86);
  backdrop-filter: blur(12px);
  border-bottom-color: var(--line);
}
.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  gap: 32px;
}
.brand { display: flex; align-items: center; gap: 10px; }
.brand-mark {
  width: 30px; height: 30px;
  display: grid; place-items: center;
  color: var(--accent);
}
.brand-text { display: flex; flex-direction: column; line-height: 1.25; }
.brand-en {
  font-family: var(--en);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.14em;
}
.brand-ja { font-size: 11px; color: var(--muted); letter-spacing: 0.06em; }

.site-nav {
  margin-left: auto;
  display: flex;
  gap: 26px;
  font-size: 13.5px;
  color: var(--muted);
}
.site-nav a { transition: color 0.2s ease; }
.site-nav a:hover { color: var(--text); }

.header-cta {
  font-size: 13px;
  padding: 9px 20px;
  border: 1px solid var(--line);
  border-radius: 999px;
  transition: border-color 0.2s ease, background 0.2s ease;
}
.header-cta:hover { border-color: var(--accent); background: rgba(77, 141, 255, 0.1); }

/* ---------- ボタン ---------- */
.btn {
  display: inline-block;
  font-size: 14.5px;
  font-weight: 700;
  letter-spacing: 0.04em;
  padding: 15px 36px;
  border-radius: 4px;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease, border-color 0.2s ease;
}
.btn-primary {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 8px 28px rgba(77, 141, 255, 0.28);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 34px rgba(77, 141, 255, 0.4); }
.btn-ghost {
  border: 1px solid var(--line);
  color: var(--text);
}
.btn-ghost:hover { border-color: var(--accent-soft); }

/* ---------- ヒーロー ---------- */
.hero {
  position: relative;
  min-height: 100svh;
  display: flex;
  align-items: center;
  overflow: hidden;
}
.hero-bg { position: absolute; inset: 0; }
.grid-layer {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(148, 163, 198, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(148, 163, 198, 0.05) 1px, transparent 1px);
  background-size: 72px 72px;
  mask-image: radial-gradient(ellipse 90% 70% at 50% 40%, #000 40%, transparent 100%);
}
.delta-field { position: absolute; inset: 0; width: 100%; height: 100%; }
.delta-field .d, .pro-bg .d {
  fill: none;
  stroke: rgba(122, 160, 235, 0.2);
  stroke-width: 1.4;
}
.delta-field .d2 { stroke: rgba(77, 141, 255, 0.34); }
.delta-field .d4 { fill: rgba(77, 141, 255, 0.1); stroke: none; }
.delta-field .d1 { animation: drift 14s ease-in-out infinite alternate; }
.delta-field .d3 { animation: drift 18s ease-in-out infinite alternate-reverse; }
@keyframes drift {
  from { transform: translateY(0); }
  to   { transform: translateY(-18px); }
}

.hero-inner {
  position: relative;
  max-width: 1080px;
  margin: 0 auto;
  padding: 120px 24px 80px;
  width: 100%;
}
.hero-eyebrow {
  font-family: var(--en);
  font-size: 12.5px;
  letter-spacing: 0.22em;
  color: var(--muted);
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 28px;
}
.hero-eyebrow .tick {
  width: 34px; height: 1px;
  background: var(--accent);
  display: inline-block;
}
.hero h1 {
  font-size: clamp(34px, 5.6vw, 64px);
  font-weight: 900;
  line-height: 1.35;
  letter-spacing: 0.02em;
  margin-bottom: 30px;
}
.hero h1 em {
  font-style: normal;
  color: var(--accent-soft);
  text-shadow: 0 0 44px rgba(77, 141, 255, 0.45);
}
.hero-lead {
  font-size: 15.5px;
  color: var(--muted);
  margin-bottom: 44px;
}
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }

.hero-foot {
  position: absolute;
  bottom: 28px; right: 32px;
}
.scroll-cue {
  font-family: var(--en);
  font-size: 10.5px;
  letter-spacing: 0.3em;
  color: var(--muted);
  writing-mode: vertical-rl;
  display: inline-flex;
  align-items: center;
  gap: 10px;
}
.scroll-cue::after {
  content: '';
  width: 1px; height: 46px;
  background: linear-gradient(var(--accent), transparent);
  animation: cue 2s ease-in-out infinite;
}
@keyframes cue {
  0%, 100% { opacity: 0.35; }
  50% { opacity: 1; }
}

/* ---------- セクション共通 ---------- */
.section { padding: 110px 0; }
.section-label {
  font-family: var(--en);
  font-size: 12px;
  letter-spacing: 0.24em;
  color: var(--accent);
  margin-bottom: 16px;
}
.section-title {
  font-size: clamp(26px, 3.4vw, 38px);
  font-weight: 900;
  letter-spacing: 0.03em;
  margin-bottom: 28px;
}

/* ---------- ABOUT ---------- */
.about { background: var(--ink-2); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.about-grid {
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 60px;
  align-items: center;
}
.about-glyph {
  aspect-ratio: 1;
  display: grid;
  place-items: center;
  border: 1px solid var(--line);
  position: relative;
}
.about-glyph::before {
  content: '';
  position: absolute;
  inset: 14px;
  border: 1px solid rgba(77, 141, 255, 0.24);
}
.about-glyph span {
  font-family: var(--en);
  font-size: 120px;
  font-weight: 500;
  color: var(--accent);
  text-shadow: 0 0 60px rgba(77, 141, 255, 0.5);
}
.about-body h2 {
  font-size: clamp(26px, 3.4vw, 38px);
  font-weight: 900;
  margin-bottom: 24px;
}
.about-body p { color: var(--muted); margin-bottom: 18px; }
.about-body p:last-child { margin-bottom: 0; }

/* ---------- TRACK RECORD ---------- */
.track-record { border-bottom: 1px solid var(--line); }
.track-lead { max-width: 660px; color: var(--muted); margin-top: -16px; }
.track-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2px;
  margin-top: 42px;
  background: var(--line);
  border: 1px solid var(--line);
}
.track-card { background: var(--ink); padding: 34px 30px; }
.track-number {
  display: block;
  font-family: var(--en);
  color: var(--accent-soft);
  font-size: clamp(38px, 4vw, 56px);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.06em;
}
.track-number span { font-size: 0.42em; letter-spacing: 0; margin-left: 4px; }
.track-card h3 { font-size: 15px; margin: 18px 0 10px; }
.track-card p { color: var(--muted); font-size: 13.5px; }
.track-note { color: var(--muted); font-size: 12.5px; margin-top: 18px; }

/* ---------- BUSINESS ---------- */
.biz-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
  margin-top: 40px;
}
.biz-card {
  position: relative;
  background: var(--ink-3);
  border: 1px solid var(--line);
  padding: 40px 36px 36px;
  overflow: hidden;
  transition: transform 0.25s ease, border-color 0.25s ease;
}
.biz-card::after {
  content: '';
  position: absolute;
  right: -34px; bottom: -34px;
  width: 96px; height: 96px;
  background: rgba(77, 141, 255, 0.07);
  clip-path: polygon(50% 0, 100% 100%, 0 100%);
  transition: transform 0.25s ease;
}
.biz-card:hover { transform: translateY(-4px); border-color: rgba(77, 141, 255, 0.4); }
.biz-card:hover::after { transform: scale(1.25); }
.biz-num {
  font-family: var(--en);
  font-size: 13px;
  letter-spacing: 0.18em;
  color: var(--accent);
  display: block;
  margin-bottom: 18px;
}
.biz-card h3 {
  font-size: 19px;
  font-weight: 700;
  margin-bottom: 14px;
  letter-spacing: 0.02em;
}
.biz-card p { font-size: 14px; color: var(--muted); }

/* ---------- FOR PROFESSIONALS ---------- */
.professionals {
  position: relative;
  background: var(--ink-2);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  overflow: hidden;
}
.pro-bg { position: absolute; inset: 0; }
.pro-bg svg { width: 100%; height: 100%; }
.professionals .container { position: relative; }
.pro-lead { color: var(--muted); margin-bottom: 48px; }
.pro-points {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
  margin-bottom: 52px;
}
.pro-point {
  border-top: 2px solid var(--accent);
  background: linear-gradient(rgba(77, 141, 255, 0.05), transparent 60%);
  padding: 28px 24px 8px;
}
.pro-point-num {
  font-family: var(--en);
  font-size: 26px;
  font-weight: 700;
  color: var(--accent);
  display: block;
  margin-bottom: 12px;
}
.pro-point h3 { font-size: 16.5px; font-weight: 700; margin-bottom: 10px; }
.pro-point p { font-size: 13.5px; color: var(--muted); }

/* ---------- COMPANY ---------- */
.company-table {
  margin-top: 40px;
  border-top: 1px solid var(--line);
}
.company-table > div {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 24px;
  padding: 26px 8px;
  border-bottom: 1px solid var(--line);
}
.company-table dt {
  font-weight: 700;
  color: var(--muted);
  font-size: 14px;
  letter-spacing: 0.06em;
}
.company-table dd { font-size: 15px; }

/* ---------- CONTACT ---------- */
.contact { background: var(--ink-2); border-top: 1px solid var(--line); text-align: center; }
.contact .section-label { text-align: center; }
.contact-lead { color: var(--muted); margin-bottom: 48px; }

.contact-form {
  max-width: 620px;
  margin: 0 auto;
  text-align: left;
}
.field { margin-bottom: 24px; }
.field label {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  margin-bottom: 10px;
  color: var(--text);
}
.field .req {
  font-family: var(--en);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--accent);
  border: 1px solid rgba(77, 141, 255, 0.4);
  border-radius: 3px;
  padding: 2px 7px;
}
.field input,
.field textarea {
  width: 100%;
  background: var(--ink);
  border: 1px solid var(--line);
  border-radius: 5px;
  color: var(--text);
  font-family: var(--ja);
  font-size: 15px;
  line-height: 1.7;
  padding: 14px 16px;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}
.field textarea { resize: vertical; min-height: 140px; }
.field input::placeholder,
.field textarea::placeholder { color: rgba(151, 163, 189, 0.5); }
.field input:focus,
.field textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(77, 141, 255, 0.15);
}
.form-submit {
  width: 100%;
  margin-top: 8px;
  cursor: pointer;
  border: none;
  font-family: var(--ja);
}
.contact-alt {
  margin-top: 28px;
  font-size: 13.5px;
  color: var(--muted);
}
.contact-alt a { color: var(--accent-soft); border-bottom: 1px solid rgba(138, 180, 255, 0.4); }
.contact-alt a:hover { color: var(--text); }

/* ---------- フッター ---------- */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 56px 0 32px;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 40px;
  flex-wrap: wrap;
}
.footer-brand { display: flex; gap: 14px; align-items: flex-start; }
.footer-brand .brand-mark { margin-top: 3px; }
.footer-name { font-weight: 700; letter-spacing: 0.04em; }
.footer-addr { font-size: 12.5px; color: var(--muted); margin-top: 6px; }
.footer-nav {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
  font-size: 13px;
  color: var(--muted);
}
.footer-nav a:hover { color: var(--text); }
.copyright {
  text-align: center;
  font-family: var(--en);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--muted);
  margin-top: 48px;
}

/* ---------- 下層ページ（プライバシーポリシー等） ---------- */
.subpage-title {
  padding: 170px 0 70px;
  background: var(--ink-2);
  border-bottom: 1px solid var(--line);
}
.subpage-title .en {
  font-family: var(--en);
  font-size: 12px;
  letter-spacing: 0.24em;
  color: var(--accent);
  display: block;
  margin-bottom: 14px;
}
.subpage-title h1 { font-size: clamp(26px, 3.4vw, 38px); font-weight: 900; }
.prose { max-width: 780px; }
.prose h2 {
  font-size: 19px;
  font-weight: 700;
  margin: 2.2em 0 0.8em;
  padding-left: 14px;
  border-left: 3px solid var(--accent);
}
.prose p, .prose li { color: var(--muted); font-size: 15px; }
.prose ul { padding-left: 1.4em; margin: 0.6em 0 1em; }
.prose a { color: var(--accent-soft); text-decoration: underline; }

/* ---------- レスポンシブ ---------- */
@media (max-width: 900px) {
  .site-nav { display: none; }
  .about-grid { grid-template-columns: 1fr; gap: 40px; }
  .about-glyph { max-width: 240px; }
  .biz-grid { grid-template-columns: 1fr; }
  .track-grid { grid-template-columns: 1fr; gap: 1px; }
  .pro-points { grid-template-columns: 1fr; }
  .company-table > div { grid-template-columns: 1fr; gap: 6px; }
  .pc { display: none; }
  .section { padding: 80px 0; }
  .hero-foot { display: none; }
}