/* ===================================
   吉成株式会社 - メインスタイルシート
   =================================== */

/* Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+JP:wght@300;400;500;700&family=Inter:wght@300;400;500;600;700&display=swap');

/* ---- リセット & ベース ---- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --color-bg: #ffffff;
  --color-surface: #f8fafc;
  --color-border: #e2e8f0;
  --color-text-primary: #0f172a;
  --color-text-secondary: #475569;
  --color-text-muted: #94a3b8;
  --color-accent: #1e40af;
  --color-accent-light: #3b82f6;
  --color-accent-hover: #1d4ed8;
  --color-white: #ffffff;
  --font-ja: 'Noto Sans JP', sans-serif;
  --font-en: 'Inter', sans-serif;
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.07), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.08);
  --shadow-lg: 0 10px 40px rgba(0,0,0,0.10);
  --transition: 0.25s ease;
  --max-width: 1100px;
}

html {
  scroll-behavior: smooth;
}

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

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition);
}

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

ul {
  list-style: none;
}

/* ---- コンテナ ---- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---- セクション ---- */
section {
  padding: 80px 0;
}

.section-label {
  font-family: var(--font-en);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-accent-light);
  margin-bottom: 12px;
}

.section-title {
  font-size: clamp(26px, 4vw, 38px);
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--color-text-primary);
  margin-bottom: 16px;
}

.section-desc {
  font-size: 16px;
  color: var(--color-text-secondary);
  max-width: 560px;
  line-height: 1.9;
}

/* ---- ヘッダー / ナビゲーション ---- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  transition: box-shadow var(--transition);
}

.site-header.scrolled {
  box-shadow: var(--shadow-sm);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.logo {
  display: flex;
  flex-direction: column;
  gap: 1px;
}

.logo-name {
  font-family: var(--font-en);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--color-text-primary);
  line-height: 1;
}

.logo-tagline {
  font-size: 10px;
  color: var(--color-text-muted);
  letter-spacing: 0.05em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 36px;
}

.nav-links a {
  font-size: 14px;
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: color var(--transition);
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -3px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-accent);
  border-radius: 2px;
  transition: width var(--transition);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-accent);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

.nav-cta {
  background: var(--color-accent) !important;
  color: var(--color-white) !important;
  padding: 9px 22px;
  border-radius: var(--radius-sm);
  font-size: 13px !important;
  font-weight: 600 !important;
  transition: background var(--transition), transform var(--transition) !important;
}

.nav-cta::after {
  display: none !important;
}

.nav-cta:hover {
  background: var(--color-accent-hover) !important;
  transform: translateY(-1px);
}

/* ハンバーガー（モバイル） */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
  background: none;
  border: none;
}

.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text-primary);
  border-radius: 2px;
  transition: all 0.3s;
}

/* ---- ボタン ---- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all var(--transition);
  font-family: var(--font-ja);
}

.btn-primary {
  background: var(--color-accent);
  color: var(--color-white);
}

.btn-primary:hover {
  background: var(--color-accent-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(30,64,175,0.25);
}

.btn-secondary {
  background: transparent;
  color: var(--color-text-primary);
  border: 1.5px solid var(--color-border);
}

.btn-secondary:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  transform: translateY(-2px);
}

/* ---- フッター ---- */
.site-footer {
  background: var(--color-text-primary);
  color: rgba(255,255,255,0.6);
  padding: 48px 0 28px;
}

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

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

.footer-logo .logo-name {
  color: var(--color-white);
  font-size: 20px;
}

.footer-logo .logo-tagline {
  color: rgba(255,255,255,0.4);
}

.footer-desc {
  font-size: 13px;
  margin-top: 10px;
  line-height: 1.9;
  max-width: 280px;
}

.footer-nav h4 {
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: rgba(255,255,255,0.4);
  margin-bottom: 16px;
  font-family: var(--font-en);
}

.footer-nav ul {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-nav a {
  font-size: 13px;
  color: rgba(255,255,255,0.6);
  transition: color var(--transition);
}

.footer-nav a:hover {
  color: var(--color-white);
}

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.08);
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}

.footer-copyright {
  font-size: 12px;
  color: rgba(255,255,255,0.35);
  font-family: var(--font-en);
}

/* ---- ユーティリティ ---- */
.text-center { text-align: center; }
.mt-8 { margin-top: 8px; }
.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }
.mt-40 { margin-top: 40px; }
.mt-48 { margin-top: 48px; }

/* ---- アニメーション ---- */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

.fade-in-delay-1 { transition-delay: 0.1s; }
.fade-in-delay-2 { transition-delay: 0.2s; }
.fade-in-delay-3 { transition-delay: 0.3s; }
.fade-in-delay-4 { transition-delay: 0.4s; }
.fade-in-delay-5 { transition-delay: 0.5s; }

/* ---- レスポンシブ ---- */
@media (max-width: 768px) {
  section { padding: 56px 0; }

  .hamburger { display: flex; }

  .nav-links {
    display: none;
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    background: var(--color-white);
    flex-direction: column;
    align-items: flex-start;
    padding: 20px 24px 28px;
    gap: 20px;
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
  }

  .nav-links.open { display: flex; }

  .nav-links a { font-size: 16px; }

  .nav-cta {
    width: 100%;
    justify-content: center;
  }

  .footer-top {
    flex-direction: column;
    gap: 32px;
  }
}