:root {
  --blue: #1565C0;
  --blue-dark: #0D47A1;
  --blue-light: #E3F2FD;
  --text: #1A1A2E;
  --muted: #546E7A;
  --bg: #FFFFFF;
  --border: #E0E0E0;
  --code-bg: #1E1E2E;
  --code-text: #CDD6F4;
  --green: #2E7D32;
  --green-light: #E8F5E9;
  --amber: #F57F17;
  --amber-light: #FFF8E1;
}

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

body {
  font-family: system-ui, -apple-system, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", "Yu Gothic", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.8;
  margin: 0;
  padding: 0;
  font-size: 15px;
}

a { color: var(--blue); }
a:hover { color: var(--blue-dark); }

/* ===== SITE HEADER ===== */
.site-header {
  background: var(--blue);
  padding: 0;
}

.site-header-inner {
  max-width: 900px;
  margin: 0 auto;
  padding: 12px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-header .logo {
  color: white;
  text-decoration: none;
  font-weight: bold;
  font-size: 15px;
}

.breadcrumb {
  display: flex;
  gap: 8px;
  align-items: center;
  font-size: 13px;
}

.breadcrumb a {
  color: rgba(255,255,255,0.75);
  text-decoration: none;
}
.breadcrumb a:hover { color: white; }
.breadcrumb .sep { color: rgba(255,255,255,0.4); }
.breadcrumb .current { color: white; }

/* ===== MAIN CONTENT ===== */
.container {
  max-width: 820px;
  margin: 0 auto;
  padding: 0 24px 80px;
}

/* ===== PAGE HEADER ===== */
.page-header {
  padding: 40px 0 28px;
  margin-bottom: 36px;
  border-bottom: 3px solid var(--blue);
}

.part-badge {
  display: inline-block;
  background: var(--blue);
  color: white;
  font-size: 11px;
  font-weight: bold;
  padding: 3px 12px;
  border-radius: 12px;
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-bottom: 14px;
}

.page-header h1 {
  font-size: 30px;
  margin: 0 0 10px;
  line-height: 1.4;
}

.page-header .lead {
  color: var(--muted);
  font-size: 15px;
  margin: 0;
}

.time-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--blue-light);
  color: var(--blue);
  font-size: 13px;
  padding: 4px 12px;
  border-radius: 20px;
  margin-top: 12px;
}

/* ===== GOAL BOX ===== */
.goal-box {
  background: var(--blue);
  color: white;
  padding: 16px 20px;
  border-radius: 10px;
  margin: 24px 0 32px;
}

.goal-box .label {
  font-size: 11px;
  font-weight: bold;
  opacity: 0.7;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 6px;
}

.goal-box p {
  margin: 0;
  font-size: 16px;
  font-weight: bold;
  line-height: 1.6;
}

/* ===== STEPS ===== */
.step {
  display: flex;
  gap: 20px;
  margin: 36px 0;
}

.step-number {
  flex-shrink: 0;
  width: 38px;
  height: 38px;
  background: var(--blue);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  font-size: 16px;
  margin-top: 2px;
}

.step-content {
  flex: 1;
  min-width: 0;
}

.step-content h3 {
  margin: 0 0 14px;
  font-size: 21px;
  color: var(--text);
  padding-top: 4px;
}

.step-content p, .step-content li {
  margin: 0 0 10px;
}

.step-content ul, .step-content ol {
  padding-left: 1.5em;
  margin: 10px 0;
}

.step-content li { margin-bottom: 6px; }

/* ===== SCREENSHOTS ===== */
.screenshot-wrap {
  margin: 20px 0;
}

.screenshot {
  width: 100%;
  max-width: 100%;
  border: 1px solid var(--border);
  border-radius: 8px;
  box-shadow: 0 2px 12px rgba(0,0,0,0.08);
  display: block;
}

figcaption, .caption {
  text-align: center;
  font-size: 13px;
  color: var(--muted);
  margin-top: 8px;
}

/* ===== CODE BLOCKS ===== */
pre {
  background: var(--code-bg);
  color: var(--code-text);
  padding: 18px 22px;
  border-radius: 8px;
  font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
  font-size: 14px;
  overflow-x: auto;
  margin: 16px 0;
  line-height: 1.6;
}

code {
  background: #EEF3FB;
  color: #0D47A1;
  padding: 2px 7px;
  border-radius: 4px;
  font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
  font-size: 0.875em;
}

pre code {
  background: none;
  color: inherit;
  padding: 0;
  font-size: inherit;
}

/* ===== CALLOUT BOXES ===== */
.callout {
  background: var(--blue-light);
  border-left: 4px solid var(--blue);
  padding: 14px 18px;
  border-radius: 0 8px 8px 0;
  margin: 16px 0;
  font-size: 14px;
}

.callout.success {
  background: var(--green-light);
  border-color: var(--green);
}

.callout.warning {
  background: var(--amber-light);
  border-color: var(--amber);
}

.callout strong {
  display: block;
  margin-bottom: 4px;
}

/* ===== DIVIDER ===== */
.section-label {
  font-size: 12px;
  font-weight: bold;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 1.5px;
  padding: 28px 0 10px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 8px;
}

/* ===== PART NAVIGATION ===== */
.part-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 28px 0;
  margin-top: 56px;
  border-top: 1px solid var(--border);
  font-size: 14px;
}

.part-nav a {
  display: flex;
  align-items: center;
  gap: 6px;
  text-decoration: none;
  padding: 8px 16px;
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--blue);
  transition: background 0.15s;
}

.part-nav a:hover {
  background: var(--blue-light);
  border-color: var(--blue);
}

/* ===== INDEX PAGE ===== */
.hero {
  padding: 60px 0 48px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 48px;
}

.hero .eyebrow {
  font-size: 13px;
  color: var(--blue);
  font-weight: bold;
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.hero h1 {
  font-size: 36px;
  line-height: 1.3;
  margin: 0 0 16px;
}

.hero .desc {
  color: var(--muted);
  font-size: 16px;
  max-width: 560px;
  line-height: 1.7;
  margin: 0;
}

.part-cards {
  display: grid;
  gap: 20px;
  margin-bottom: 56px;
}

.part-card {
  display: flex;
  gap: 20px;
  padding: 24px;
  border: 1px solid var(--border);
  border-radius: 12px;
  text-decoration: none;
  color: var(--text);
  transition: box-shadow 0.2s, border-color 0.2s, transform 0.1s;
}

.part-card:hover {
  box-shadow: 0 4px 20px rgba(21,101,192,0.12);
  border-color: var(--blue);
  transform: translateY(-1px);
}

.part-card-number {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  background: var(--blue);
  color: white;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  font-size: 20px;
}

.part-card-body { flex: 1; }

.part-card-body .part-label {
  font-size: 11px;
  font-weight: bold;
  color: var(--blue);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 6px;
}

.part-card-body h2 {
  margin: 0 0 8px;
  font-size: 18px;
}

.part-card-body p {
  margin: 0;
  font-size: 14px;
  color: var(--muted);
  line-height: 1.6;
}

.part-card-body .steps-list {
  margin: 10px 0 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.part-card-body .steps-list li {
  font-size: 12px;
  background: var(--blue-light);
  color: var(--blue);
  padding: 2px 10px;
  border-radius: 12px;
}

/* ===== FOOTER ===== */
footer {
  padding: 28px 0;
  text-align: center;
  font-size: 13px;
  color: var(--muted);
  border-top: 1px solid var(--border);
  margin-top: 64px;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 600px) {
  .container { padding: 0 16px 60px; }
  .hero h1 { font-size: 26px; }
  .page-header h1 { font-size: 22px; }
  .step { gap: 14px; }
  .step-number { width: 32px; height: 32px; font-size: 14px; }
  .part-card { flex-direction: column; gap: 12px; }
  pre { font-size: 12px; }
}