/* アイのあるミライ 公式サイト — 基礎スタイル / ヘッダー / フッター */

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: var(--font-ja);
  font-size: var(--step-0);
  line-height: 1.85;
  color: var(--ink);
  background-color: var(--bg);
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 64px 64px, 64px 64px;
  overflow-x: hidden;
  transition: background-color 0.4s var(--ease), color 0.4s var(--ease);
}

body.is-locked {
  overflow: hidden;
}

h1, h2, h3, h4 {
  margin: 0;
  line-height: 1.25;
  font-weight: 900;
  letter-spacing: 0.01em;
}

p {
  margin: 0;
}

img {
  display: block;
  max-width: 100%;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
  color: inherit;
  border: none;
  background: none;
  cursor: pointer;
}

ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

:focus-visible {
  outline: 3px solid var(--brand-cyan);
  outline-offset: 3px;
  border-radius: 4px;
}

::selection {
  background: var(--brand-pink);
  color: #fff;
}

/* ---------- 汎用ユーティリティ ---------- */

section[id],
main[id] {
  scroll-margin-top: 92px;
}

.shell {
  width: min(100% - var(--gutter) * 2, var(--page));
  margin-inline: auto;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-en);
  font-size: var(--step--1);
  font-weight: 700;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

.eyebrow::before {
  content: "";
  width: 26px;
  height: 2px;
  background: linear-gradient(90deg, var(--brand-pink), var(--brand-cyan));
}

.section-title {
  font-size: var(--step-3);
  margin-block: 14px 18px;
  text-wrap: balance;
}

.section-lead {
  max-width: 54ch;
  color: var(--ink-soft);
  font-size: var(--step-1);
}

.grad-text {
  background: linear-gradient(100deg, var(--brand-pink), var(--brand-cyan));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* ---------- ボタン ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 28px;
  border-radius: var(--radius-pill);
  font-weight: 700;
  font-size: var(--step-0);
  line-height: 1;
  transition: transform 0.4s var(--ease), box-shadow 0.4s var(--ease), background 0.3s var(--ease), color 0.3s var(--ease);
  will-change: transform;
}

.btn:hover {
  transform: translateY(-3px);
}

.btn-primary {
  color: #fff;
  background: linear-gradient(100deg, var(--brand-pink), var(--brand-cyan));
  box-shadow: 0 14px 30px -14px var(--glow-pink);
}

.btn-primary:hover {
  box-shadow: 0 22px 44px -16px var(--glow-pink);
}

.btn-ghost {
  border: 1.5px solid var(--line-strong);
  background: var(--surface);
}

.btn-ghost:hover {
  border-color: var(--brand-cyan);
  color: var(--brand-cyan);
}

.btn .arrow {
  transition: transform 0.4s var(--ease);
}

.btn:hover .arrow {
  transform: translateX(4px);
}

/* ---------- スクロール進捗 ---------- */

.scroll-progress {
  position: fixed;
  inset: 0 auto auto 0;
  z-index: 90;
  width: 100%;
  height: 3px;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--brand-pink), var(--brand-cyan));
}

/* ---------- ヘッダー ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  backdrop-filter: blur(20px) saturate(1.4);
  -webkit-backdrop-filter: blur(20px) saturate(1.4);
  background: var(--header-bg);
  border-bottom: 1px solid transparent;
  transition: border-color 0.35s var(--ease), background 0.35s var(--ease);
}

.site-header.is-stuck {
  border-bottom-color: var(--line);
}

.header-inner {
  display: flex;
  align-items: center;
  gap: 20px;
  min-height: 72px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  margin-right: auto;
}

.brand img {
  width: 40px;
  height: 40px;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: #fff;
}

.brand-text strong {
  display: block;
  font-size: 1rem;
  font-weight: 900;
  letter-spacing: 0.04em;
  line-height: 1.2;
}

.brand-text span {
  display: block;
  font-family: var(--font-en);
  font-size: 0.64rem;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 4px;
}

.site-nav a {
  position: relative;
  padding: 10px 14px;
  font-size: 0.9rem;
  font-weight: 700;
  border-radius: var(--radius-pill);
  transition: color 0.3s var(--ease);
}

.site-nav a::after {
  content: "";
  position: absolute;
  left: 14px;
  right: 14px;
  bottom: 6px;
  height: 2px;
  background: linear-gradient(90deg, var(--brand-pink), var(--brand-cyan));
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform 0.4s var(--ease);
}

.site-nav a:hover::after,
.site-nav a.is-current::after {
  transform: scaleX(1);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.icon-btn {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  border: 1.5px solid var(--line);
  background: var(--surface);
  transition: border-color 0.3s var(--ease), transform 0.3s var(--ease), color 0.3s var(--ease);
}

.icon-btn:hover {
  border-color: var(--brand-cyan);
  color: var(--brand-cyan);
  transform: translateY(-2px);
}

.theme-toggle .sun { display: none; }
[data-theme="dark"] .theme-toggle .sun { display: block; }
[data-theme="dark"] .theme-toggle .moon { display: none; }

.header-cta {
  padding: 12px 22px;
  font-size: 0.88rem;
}

.nav-toggle {
  display: none;
}

/* ---------- モバイル用オーバーレイメニュー ---------- */

.nav-overlay {
  position: fixed;
  inset: 0;
  z-index: 95;
  display: grid;
  align-content: center;
  gap: 8px;
  padding: 0 var(--gutter);
  background: var(--bg);
  clip-path: circle(0% at calc(100% - 44px) 44px);
  transition: clip-path 0.65s var(--ease);
  visibility: hidden;
}

.nav-overlay.is-open {
  clip-path: circle(150% at calc(100% - 44px) 44px);
  visibility: visible;
}

.nav-overlay a {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 10px 0;
  font-size: clamp(2rem, 11vw, 3.4rem);
  font-weight: 900;
  border-bottom: 1px solid var(--line);
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
}

.nav-overlay.is-open a {
  opacity: 1;
  transform: none;
}

.nav-overlay a span {
  font-family: var(--font-en);
  font-size: 0.72rem;
  letter-spacing: 0.2em;
  color: var(--ink-faint);
}

.nav-overlay-close {
  position: absolute;
  top: 22px;
  right: var(--gutter);
}

/* ---------- 出現アニメーション ---------- */

.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.8s var(--ease), transform 0.8s var(--ease);
  transition-delay: var(--delay, 0ms);
}

.reveal.is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- フッター ---------- */

.site-footer {
  position: relative;
  padding-block: clamp(56px, 8vw, 96px) 36px;
  border-top: 1px solid var(--line);
  background: var(--bg-alt);
}

.footer-top {
  display: flex;
  flex-wrap: wrap;
  gap: 40px;
  justify-content: space-between;
  align-items: flex-start;
}

.footer-brand {
  max-width: 34ch;
  display: grid;
  gap: 16px;
}

.footer-brand img {
  width: 76px;
  border-radius: 18px;
  border: 1px solid var(--line);
  background: #fff;
}

.footer-brand p {
  color: var(--ink-soft);
  font-size: 0.92rem;
}

.footer-cols {
  display: flex;
  flex-wrap: wrap;
  gap: clamp(32px, 6vw, 72px);
}

.footer-col h3 {
  font-family: var(--font-en);
  font-size: 0.7rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-bottom: 14px;
}

.footer-col li + li {
  margin-top: 8px;
}

.footer-col a {
  font-size: 0.92rem;
  font-weight: 700;
  transition: color 0.3s var(--ease);
}

.footer-col a:hover {
  color: var(--brand-pink);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: space-between;
  align-items: center;
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
  font-size: 0.78rem;
  color: var(--ink-faint);
  font-family: var(--font-en);
  letter-spacing: 0.08em;
}

/* ---------- レスポンシブ ---------- */

/* ナビとCTAが窮屈になる前に、CTAから先に畳む */
@media (max-width: 1100px) {
  .header-cta {
    display: none;
  }
}

@media (max-width: 900px) {
  .site-nav {
    display: none;
  }

  .nav-toggle {
    display: grid;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }
}