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

:root {
  --blue: #1a56db;
  --blue-light: #e8f0fe;
  --blue-mid: #3b82f6;
  --indigo: #3730a3;
  --green: #059669;
  --green-light: #d1fae5;
  --orange: #d97706;
  --orange-light: #fef3c7;
  --red: #dc2626;
  --red-light: #fee2e2;
  --purple: #7c3aed;
  --purple-light: #ede9fe;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-400: #9ca3af;
  --gray-600: #4b5563;
  --gray-800: #1f2937;
  --gray-900: #111827;
  --white: #ffffff;
  --shadow: 0 4px 24px rgba(26,86,219,0.10);
  --radius: 16px;
}

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

body {
  font-family: 'Noto Sans JP', sans-serif;
  background: var(--gray-50);
  color: var(--gray-800);
  line-height: 1.7;
}

/* ===== HEADER ===== */
.page-header {
  background: linear-gradient(135deg, #1a56db 0%, #3730a3 100%);
  color: white;
  padding: 52px 24px 40px;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.page-header::before {
  content: '';
  position: absolute;
  top: -60px; right: -60px;
  width: 260px; height: 260px;
  border-radius: 50%;
  background: rgba(255,255,255,0.07);
  pointer-events: none;
}
.page-header::after {
  content: '';
  position: absolute;
  bottom: -80px; left: -40px;
  width: 200px; height: 200px;
  border-radius: 50%;
  background: rgba(255,255,255,0.05);
  pointer-events: none;
}
.header-badge {
  display: inline-block;
  background: rgba(255,255,255,0.18);
  border: 1px solid rgba(255,255,255,0.3);
  border-radius: 999px;
  padding: 4px 18px;
  font-size: 12px;
  letter-spacing: 0.1em;
  margin-bottom: 14px;
  font-family: 'Space Mono', monospace;
}
.page-header h1 {
  font-size: clamp(24px, 4vw, 40px);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 10px;
}
.page-header p {
  font-size: 15px;
  opacity: 0.85;
  max-width: 520px;
  margin: 0 auto;
  font-weight: 300;
}
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: rgba(255,255,255,0.75);
  text-decoration: none;
  font-size: 13px;
  margin-bottom: 20px;
  transition: color 0.2s;
}
.back-link:hover { color: white; }

/* ===== NAV ===== */
.nav-wrap {
  background: white;
  border-bottom: 1px solid var(--gray-200);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 12px rgba(0,0,0,0.06);
}
nav {
  max-width: 980px;
  margin: 0 auto;
  display: flex;
  overflow-x: auto;
  scrollbar-width: none;
  padding: 0 12px;
}
nav::-webkit-scrollbar { display: none; }
nav a {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 14px 16px;
  font-size: 13px;
  font-weight: 500;
  color: var(--gray-600);
  text-decoration: none;
  border-bottom: 3px solid transparent;
  white-space: nowrap;
  transition: all 0.2s;
}
nav a:hover { color: var(--blue); border-bottom-color: var(--blue-light); }
nav a.active { color: var(--blue); border-bottom-color: var(--blue); }
nav a .ni { font-size: 16px; }

/* ===== MAIN ===== */
main {
  max-width: 980px;
  margin: 0 auto;
  padding: 40px 20px 80px;
}

/* ===== SECTION ===== */
.section { margin-bottom: 60px; }
.section-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 24px;
  padding-bottom: 14px;
  border-bottom: 2px solid var(--blue-light);
}
.section-num {
  width: 46px; height: 46px;
  background: var(--blue);
  color: white;
  border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
  font-family: 'Space Mono', monospace;
  font-size: 18px;
  font-weight: 700;
  flex-shrink: 0;
}
.section-title { font-size: 20px; font-weight: 700; color: var(--gray-900); }
.section-sub { font-size: 13px; color: var(--gray-400); margin-top: 2px; }

/* ===== STEPS ===== */
.steps { display: flex; flex-direction: column; gap: 18px; }
.step {
  background: white;
  border-radius: var(--radius);
  padding: 22px;
  box-shadow: var(--shadow);
  border: 1px solid var(--gray-100);
  display: grid;
  grid-template-columns: 38px 1fr;
  gap: 14px;
  align-items: start;
  transition: transform 0.2s, box-shadow 0.2s;
}
.step:hover { transform: translateY(-2px); box-shadow: 0 8px 32px rgba(26,86,219,0.13); }
.step-circle {
  width: 38px; height: 38px;
  background: var(--blue-light);
  color: var(--blue);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700;
  font-size: 15px;
  font-family: 'Space Mono', monospace;
  flex-shrink: 0;
}
.step h3 { font-size: 15px; font-weight: 700; margin-bottom: 6px; color: var(--gray-900); }
.step p { font-size: 14px; color: var(--gray-600); }

.arrow-down { text-align: center; color: var(--blue-mid); font-size: 20px; margin: -6px 0; opacity: 0.45; }

/* ===== SCREEN MOCKUP ===== */
.screen-wrap {
  margin-top: 14px;
  background: var(--gray-100);
  border-radius: 10px;
  padding: 10px;
  border: 1px solid var(--gray-200);
}
.browser-bar {
  background: var(--gray-200);
  border-radius: 8px 8px 0 0;
  padding: 7px 10px;
  display: flex;
  align-items: center;
  gap: 5px;
}
.browser-dot { width: 9px; height: 9px; border-radius: 50%; }
.d-red { background: #ef4444; } .d-yellow { background: #f59e0b; } .d-green { background: #10b981; }
.browser-url {
  background: white;
  border-radius: 4px;
  padding: 2px 10px;
  font-size: 11px;
  color: var(--gray-600);
  margin-left: 6px;
  font-family: 'Space Mono', monospace;
  flex: 1;
}
.browser-content { background: white; border-radius: 0 0 8px 8px; overflow: hidden; }

/* ===== HIGHLIGHT BOXES ===== */
.highlight {
  border-radius: 12px;
  padding: 16px 18px;
  margin: 16px 0;
  display: flex;
  gap: 12px;
  align-items: flex-start;
  font-size: 14px;
}
.highlight.info { background: var(--blue-light); border-left: 4px solid var(--blue); }
.highlight.warning { background: var(--orange-light); border-left: 4px solid var(--orange); }
.highlight.success { background: var(--green-light); border-left: 4px solid var(--green); }
.highlight.danger { background: var(--red-light); border-left: 4px solid var(--red); }
.highlight .hi-icon { font-size: 18px; flex-shrink: 0; margin-top: 1px; }
.highlight strong { display: block; margin-bottom: 3px; }

/* ===== TAG ===== */
.tag {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 99px;
  font-size: 12px;
  font-weight: 600;
  margin-right: 4px;
}
.tag.blue { background: var(--blue-light); color: var(--blue); }
.tag.green { background: var(--green-light); color: var(--green); }
.tag.orange { background: var(--orange-light); color: var(--orange); }
.tag.purple { background: var(--purple-light); color: var(--purple); }

/* ===== FAQ ===== */
.faq-item {
  background: white;
  border-radius: var(--radius);
  padding: 18px 22px;
  box-shadow: var(--shadow);
  border: 1px solid var(--gray-100);
  margin-bottom: 12px;
}
.faq-item .faq-q { font-weight: 700; color: var(--blue); margin-bottom: 7px; }
.faq-item .faq-a { font-size: 14px; color: var(--gray-600); }

/* ===== FOOTER ===== */
footer {
  background: var(--gray-900);
  color: rgba(255,255,255,0.55);
  text-align: center;
  padding: 28px;
  font-size: 13px;
}
footer strong { color: white; }
footer a { color: rgba(255,255,255,0.7); text-decoration: none; }
footer a:hover { color: white; }

/* ===== RESPONSIVE ===== */
@media (max-width: 600px) {
  .step { grid-template-columns: 1fr; }
  .step-circle { display: none; }
}