@charset "UTF-8";

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", Arial, "Hiragino Sans", "Hiragino Kaku Gothic ProN", Meiryo, sans-serif;
  font-size: 16px;
  line-height: 1.8;
  color: #1f2937;
  background: #fff; }

h1 {
  font-size: 1.75em;
  font-weight: 700;
  letter-spacing: -0.01em; }

h2 {
  font-size: 1.4em;
  font-weight: 700;
  padding-bottom: 8px;
  border-bottom: 2px solid #e5e7eb; }

h3 {
  font-size: 1.15em;
  font-weight: 600; }

h1, h2, h3 {
  margin-top: 36px;
  margin-bottom: 16px;
  color: #111827; }

h4, h5, h6 {
  margin-top: 20px;
  margin-bottom: 12px;
  font-weight: 600; }
  h4:before, h5:before, h6:before {
    content: "■";
    margin-right: 0.3em;
    color: #9ca3af; }

p {
  margin-bottom: 16px; }

dd {
  margin-left: 3em; }

/* --- Column / Callout --- */
div.column {
  border: 1px solid #e5e7eb;
  border-left: 4px solid #6b7280;
  border-radius: 6px;
  padding: 16px 20px;
  margin-top: 16px;
  margin-bottom: 16px;
  background: #f9fafb; }
  div.column h1, div.column h2, div.column h3 {
    margin-top: 8px;
    border-bottom: none;
    font-size: 1em; }

div.lead {
  font-size: 16px;
  margin-left: 3em; }

p.flushright {
  text-align: right; }

/* --- Footnotes --- */
.noteref {
  vertical-align: super;
  font-size: smaller;
  color: #2563eb;
  text-decoration: none; }

p.footnote {
  font-size: 0.85em;
  color: #4b5563;
  padding-top: 8px;
  border-top: 1px solid #f3f4f6; }

.main-content {
  display: flex;
  flex-direction: column; }

div.footnote {
  order: 1; }

/* --- Images / Tables / Code --- */
.image, .table, .caption-code, .cmd-code {
  margin-bottom: 20px; }

.image .caption, .table .caption {
  text-align: center;
  font-size: 0.9em;
  color: #4b5563; }

.image .caption {
  margin-top: 4px; }
  .image .caption:before {
    content: "▲";
    margin-right: 0.3em;
    color: #d1d5db; }

.caption-code .caption, .table .caption {
  margin-bottom: 4px; }
  .caption-code .caption:before, .table .caption:before {
    content: "▼";
    margin-right: 0.3em;
    color: #d1d5db; }

.image img {
  display: block;
  max-width: 100%;
  height: auto;
  margin-left: auto;
  margin-right: auto; }

/* --- Code blocks --- */
pre, code {
  font-family: "SF Mono", "Menlo", "Consolas", monospace;
  font-size: 0.9em; }

pre {
  background: #f8f9fa;
  border: 1px solid #e5e7eb;
  border-radius: 6px;
  padding: 16px;
  overflow-x: auto;
  line-height: 1.6; }

code {
  background: #f3f4f6;
  padding: 0.15em 0.4em;
  border-radius: 4px; }

pre code {
  background: none;
  padding: 0;
  border-radius: 0; }

/* --- Tables --- */
table {
  border-collapse: collapse;
  width: 100%;
  margin-bottom: 16px;
  font-size: 0.95em; }

th, td {
  border: 1px solid #e5e7eb;
  padding: 8px 12px;
  text-align: left; }

th {
  background: #f8f9fa;
  font-weight: 600; }

/* --- Links --- */
a {
  color: #2563eb;
  text-decoration: none; }

a:hover {
  text-decoration: underline; }

/* --- Legacy header/footer (TechBooster) --- */
.tb-header {
  background-image: url(images/html_header.jpg);
  background-size: cover;
  height: 20vw;
  background-color: #64C1D7;
  color: white;
  text-indent: 150%;
  overflow: hidden;
  white-space: nowrap; }

.tb-nav-link {
  margin-top: 1em;
  margin-bottom: 1em; }
  .tb-nav-link a.prev:before {
    content: "<<"; }
  .tb-nav-link a.next:after {
    content: ">>"; }

.tb-footer {
  margin-top: 16px;
  padding-top: 16px;
  padding-bottom: 16px;
  color: white;
  background-color: #424242; }
  .tb-footer a {
    color: #9e9e9e; }
  .tb-footer p {
    margin-right: 10px; }

.tb-footer-links li:nth-child(n+2)::before {
  color: #9e9e9e;
  content: "/";
  margin-right: 16px; }